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Pathogens, Volume 9, Issue 7 (July 2020) – 82 articles

Cover Story (view full-size image): Campylobacter jejuni is a major foodborne pathogen with broad host specificity and a common cause of bacterial enteritis worldwide. PFGE or 7-loci MLST have traditionally been used to trace foodborne C. jejuni infections to the source animal. In this study, we use all 1343 loci of the Campylobacter core genome to analyze 622 strains isolated from food animals through the NARMS program and 222 strains from human patients. The cgMLST typing scheme, allowing for a 200-allele difference, revealed that ~80% of cattle isolates shared a typing group with human isolates, compared to only 40% of chicken isolates categorized with humans. Further, certain AMR and virulence markers were highly conserved within specific groups and animal sources. This typing scheme combined with AMR data can provide an excellent tool for source attribution of C. jejuni infections. View this paper
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17 pages, 2337 KiB  
Article
Molecular Characterization of Clistobothrium sp. Viable Plerocercoids in Fresh Longfin Inshore Squid (Doryteuthis pealeii) and Implications for Cephalopod Inspection
by Lisa Guardone, Alice Giusti, Ewa Bilska-Zajac, Renato Malandra, Miroslaw Różycki and Andrea Armani
Pathogens 2020, 9(7), 596; https://doi.org/10.3390/pathogens9070596 - 21 Jul 2020
Cited by 6 | Viewed by 3748
Abstract
Cephalopods, an appreciated seafood product, are common hosts of marine cestodes. The aim of this work is to report visible alive plerocercoids in longfin inshore squid (Doryteuthis pealeii), a cephalopod species commercialized as fresh and whole in Italy. Seventy D. pealeii [...] Read more.
Cephalopods, an appreciated seafood product, are common hosts of marine cestodes. The aim of this work is to report visible alive plerocercoids in longfin inshore squid (Doryteuthis pealeii), a cephalopod species commercialized as fresh and whole in Italy. Seventy D. pealeii from the Northwest Atlantic (FAO area 21) were collected and visually inspected. In total, 18 plerocercoid larvae were found in the viscera of 10 host specimens (P: 14.3% 95% CI 7.1–24.7; MI: 1.8, MA: 0.26; range 1–4) and molecularly analyzed targeting the variable D2 region of the large subunit (LSU) rRNA gene and the cytochrome c oxidase subunit I (COI) gene. The molecular characterization allowed to identify all the plerocercoids as Clistobothrium sp., a cestode of the Phyllobothriidae family with Lamnidae sharks as definitive hosts, and cephalopods as second intermediate hosts. These findings represent the first molecular record of Clistobothrium sp. in D. pealeii, thus contributing to elucidate its poorly known life cycle. Even if not affecting consumer’s health, these visible parasites may represent a reason for disgust for consumers. Therefore, the results suggest that Food Business Operators should also check for the presence of these visible parasites during inspection and underline the importance of a correct consumers’ education. Full article
(This article belongs to the Special Issue Animal Parasitic Diseases)
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14 pages, 669 KiB  
Article
First Report on the Occurrence and Subtypes of Blastocystis in Pigs in Poland Using Sequence-Tagged-Site PCR and Barcode Region Sequencing
by Monika Rudzińska, Beata Kowalewska, Beata Szostakowska, Maciej Grzybek, Katarzyna Sikorska and Agnieszka Świątalska
Pathogens 2020, 9(7), 595; https://doi.org/10.3390/pathogens9070595 - 21 Jul 2020
Cited by 11 | Viewed by 2376
Abstract
Blastocystis is an enteric microorganism commonly found in humans and animals worldwide. Its pathogenic role in humans and transmission patterns has not been fully explained. However, nine subtypes (ST1–8, ST12) are considered as potentially zoonotic. Studies from various regions of the world show [...] Read more.
Blastocystis is an enteric microorganism commonly found in humans and animals worldwide. Its pathogenic role in humans and transmission patterns has not been fully explained. However, nine subtypes (ST1–8, ST12) are considered as potentially zoonotic. Studies from various regions of the world show that pigs are mainly infected with ST5. Although pigs are important farmed animals in Poland, the question of Blastocystis infection in these animals has not yet been investigated. Herein, 149 pig stool samples from 10 Polish pig farms were analyzed using sequence-tagged-site PCR and barcode region sequencing. The percentage of samples in which Blastocystis was identified using each method separately was similar: 38.25% and 37.58%, respectively. However, the percentage of positive results obtained by combining both methods was 46.97%, which means that, depending on the method used, the number of undetected samples varied between 8.72% and 9.39%. This shows the methodological limitations of up-to-date molecular approaches commonly used in Blastocystis research. A moderate infection rate (44.4–50%) observed in different pig age groups with a vital predominance of ST5 (94.28%) in every age group shows that pigs are a likely natural host of ST5. A small percentage of mixed infections, namely ST5/ST1 (5.26%), ST5/ST3 (1.75%), and ST3/ST1 (1.75%), was observed only in animals of older age, suggesting that ST3 and ST1 can be acquired by pigs during contact with humans. This study provides the first data on the prevalence and Blastocystis subtypes (STs) distribution in pigs in Poland. The results also highlight the need for the development of new methods capable of detecting highly genetically diverse Blastocystis isolates and mixed infections. Full article
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23 pages, 16329 KiB  
Article
The Epstein-Barr Virus-Encoded EBNA1 Protein Activates the Bone Morphogenic Protein (BMP) Signalling Pathway to Promote Carcinoma Cell Migration
by Hannah E. Bridgewater, Kathryn L. Date, John D. O’Neil, Chunfang Hu, John R. Arrand, Christopher W. Dawson and Lawrence S. Young
Pathogens 2020, 9(7), 594; https://doi.org/10.3390/pathogens9070594 - 21 Jul 2020
Cited by 7 | Viewed by 3345
Abstract
The Epstein-Barr virus (EBV)-encoded nuclear antigen 1 (EBNA1) protein is expressed in all virus-associated malignancies, where it performs an essential role in the maintenance, replication and transcription of the EBV genome. In recent years, it has become apparent that EBNA1 can also influence [...] Read more.
The Epstein-Barr virus (EBV)-encoded nuclear antigen 1 (EBNA1) protein is expressed in all virus-associated malignancies, where it performs an essential role in the maintenance, replication and transcription of the EBV genome. In recent years, it has become apparent that EBNA1 can also influence cellular gene transcription. Here, we demonstrate that EBNA1 is able to stimulate the expression of the Transforming growth factor-beta (TGFβ) superfamily member, bone morphogenic protein 2 (BMP2), with consequential activation of the BMP signalling pathway in carcinoma cell lines. We show that BMP pathway activation is associated with an increase in the migratory capacity of carcinoma cells, an effect that can be ablated by the BMP antagonist, Noggin. Gene expression profiling of authentic EBV-positive nasopharyngeal carcinoma (NPC) tumours revealed the consistent presence of BMP ligands, established BMP pathway effectors and putative target genes, constituting a prominent BMP “signature” in this virus-associated cancer. Our findings show that EBNA1 is the major viral-encoded protein responsible for activating the BMP signalling pathway in carcinoma cells and supports a role for this pathway in promoting cell migration and possibly, metastatic spread. Full article
(This article belongs to the Section Human Pathogens)
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15 pages, 2267 KiB  
Article
Monitoring Mycoplasma bovis Diversity and Antimicrobial Susceptibility in Calf Feedlots Undergoing a Respiratory Disease Outbreak
by Claire A.M. Becker, Chloé Ambroset, Anthéa Huleux, Angélique Vialatte, Adélie Colin, Agnès Tricot, Marie-Anne Arcangioli and Florence Tardy
Pathogens 2020, 9(7), 593; https://doi.org/10.3390/pathogens9070593 - 21 Jul 2020
Cited by 19 | Viewed by 3550
Abstract
Bovine respiratory diseases (BRD) are widespread in veal calf feedlots. Several pathogens are implicated, both viruses and bacteria, one of which, Mycoplasma bovis, is under-researched. This worldwide-distributed bacterium has been shown to be highly resistant in vitro to the main antimicrobials used [...] Read more.
Bovine respiratory diseases (BRD) are widespread in veal calf feedlots. Several pathogens are implicated, both viruses and bacteria, one of which, Mycoplasma bovis, is under-researched. This worldwide-distributed bacterium has been shown to be highly resistant in vitro to the main antimicrobials used to treat BRD. Our objective was to monitor the relative prevalence of M. bovis during BRD episodes, its diversity, and its resistance phenotype in relation to antimicrobial use. For this purpose, a two-year longitudinal follow-up of 25 feedlots was organized and 537 nasal swabs were collected on 358 veal calves at their arrival in the lot, at the BRD peak and 4 weeks after collective antimicrobial treatments. The presence of M. bovis was assessed by real-time PCR and culture. The clones isolated were then subtyped (polC subtyping and PFGE analysis), and their susceptibility to five antimicrobials was determined. The course of the disease and the antimicrobials used had no influence on the genetic diversity of the M. bovis strains: The subtype distribution was the same throughout the BRD episode and similar to that already described in France, with a major narrowly-variable subtype circulating, st2. The same conclusion holds for antimicrobial resistance (AMR) phenotypes: All the clones were already multiresistant to the main antimicrobials used (except for fluoroquinolones) prior to any treatments. By contrast, changes of AMR phenotypes could be suspected for Pasteurellaceae in two cases in relation to the treatments registered. Full article
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18 pages, 3015 KiB  
Article
Mycobacterium bovis Population Structure in Cattle and Local Badgers: Co-Localisation and Variation by Farm Type
by Georgina Milne, Adrian Allen, Jordon Graham, Raymond Kirke, Carl McCormick, Eleanor Presho, Robin Skuce and Andrew W. Byrne
Pathogens 2020, 9(7), 592; https://doi.org/10.3390/pathogens9070592 - 21 Jul 2020
Cited by 8 | Viewed by 2876
Abstract
Bovine tuberculosis surveillance in Northern Ireland includes Multiple-Locus Variable number tandem repeat Analysis (MLVA) to determine the Mycobacterium bovis genetic type present in both cattle and the predominant wildlife host, the European badger (Meles meles). These data are useful for investigating [...] Read more.
Bovine tuberculosis surveillance in Northern Ireland includes Multiple-Locus Variable number tandem repeat Analysis (MLVA) to determine the Mycobacterium bovis genetic type present in both cattle and the predominant wildlife host, the European badger (Meles meles). These data are useful for investigating clusters of infection and understanding the scale at which interspecific transmission may occur. We utilised a comprehensive dataset of routinely sampled isolates from infected cattle and from badgers killed in road-traffic accidents to investigate the spatial co-location of MLVA types in, and between, the badger and cattle populations. Furthermore, we investigated the hypothesis that the type of farming enterprise might explain some variation in this relationship. MLVA types were spatially co-localised in cattle and road-traffic accident (RTA) badger hosts, indicative of a shared epidemic. Dairy herds were more likely to have at least one MLVA type in common with nearby RTA badgers, compared to non-dairy herd types. Marginally more MLVA spatial clustering was observed in non-dairy herds, which may be a consequence of relatively more between-herd movements. For the cattle population, local transmission mechanisms such as infection from contiguous herds, infectious wildlife and short-range between-herd cattle movements appear primarily to drive the epidemic: there appears to be a more limited role for long-range movements. Animal management practices are likely to be the driving force behind this observation, as beef rearing is associated with elevated numbers of animal movements compared to dairy herds. Full article
(This article belongs to the Special Issue Tuberculosis Epidemiology and Control in Multi-Host Systems)
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12 pages, 1810 KiB  
Case Report
Concurrent Infection of Skunk Adenovirus-1, Listeria monocytogenes, and a Regionally Specific Clade of Canine Distemper Virus in One Gray Fox (Urocyon cinereoargenteus) and Concurrent Listeriosis and Canine Distemper in a Second Gray Fox
by David B. Needle, Jacqueline L. Marr, Cooper J. Park, Cheryl P. Andam, Annabel G. Wise, Roger K. Maes, Rebecca P. Wilkes, Eman A. Anis, Inga F. Sidor, Dalen Agnew, Julie C. Ellis, Patrick Tate, Abigail Mathewson, Christopher Benton and Robert Gibson
Pathogens 2020, 9(7), 591; https://doi.org/10.3390/pathogens9070591 - 21 Jul 2020
Cited by 11 | Viewed by 3852
Abstract
One free-ranging Gray fox (Urocyon cinereoargenteus) underwent autopsy following neurologic disease, with findings including morbilliviral inclusions and associated lesions in numerous tissues, adenoviral intranuclear inclusions in bronchial epithelial cells, and septic pleuropneumonia, hepatitis, splenitis, and meningoencephalitis. Molecular diagnostics on fresh lung [...] Read more.
One free-ranging Gray fox (Urocyon cinereoargenteus) underwent autopsy following neurologic disease, with findings including morbilliviral inclusions and associated lesions in numerous tissues, adenoviral intranuclear inclusions in bronchial epithelial cells, and septic pleuropneumonia, hepatitis, splenitis, and meningoencephalitis. Molecular diagnostics on fresh lung identified a strain within a distinct clade of canine distemper that is currently unique to wildlife in New England, as well as the emerging multi-host viral pathogen skunk adenovirus-1. Bacterial culture of fresh liver resulted in a pure growth of Listeria monocytogenes, with whole genome sequencing indicating that the isolate had a vast array of antimicrobial resistance and virulence-associated genes. One year later, a second fox was euthanized for inappropriate behavior in a residential area, and diagnostic workup revealed canine distemper and septic L. monocytogenes, with the former closely related to the distemper virus found in the previous fox and the latter divergent from the L. monocytogenes from the previous fox. Full article
(This article belongs to the Special Issue Canine Distemper Virus Infection)
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9 pages, 433 KiB  
Review
Understanding HCMV Latency Using Unbiased Proteomic Analyses
by Emma Poole and John Sinclair
Pathogens 2020, 9(7), 590; https://doi.org/10.3390/pathogens9070590 - 20 Jul 2020
Cited by 12 | Viewed by 3304
Abstract
Human cytomegalovirus (HCMV) establishes either a latent (non-productive) or lytic (productive) infection depending upon cell type, cytokine milieu and the differentiation status of the infected cell. Undifferentiated cells, such as precursor cells of the myeloid lineage, support a latent infection whereas terminally differentiated [...] Read more.
Human cytomegalovirus (HCMV) establishes either a latent (non-productive) or lytic (productive) infection depending upon cell type, cytokine milieu and the differentiation status of the infected cell. Undifferentiated cells, such as precursor cells of the myeloid lineage, support a latent infection whereas terminally differentiated cells, such as monocytes or dendritic cells are an environment conducive to reactivation and support a lytic infection. The mechanisms which regulate HCMV in either a latent or lytic infection have been the focus of intense investigation with a view to developing novel treatments for HCMV-associated disease which can have a heavy clinical burden after reactivation or primary infection in, especially, the immune compromised. To this end, a number of studies have been carried out in an unbiased manner to address global changes occurring within the latently infected cell to address the molecular changes associated with HCMV latency. In this review, we will concentrate on the proteomic analyses which have been carried out in undifferentiated myeloid cells which either stably express specific viral latency associated genes in isolation or on cells which have been latently infected with virus. Full article
(This article belongs to the Special Issue Cytomegalovirus (CMV) Infection and Latency)
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51 pages, 2593 KiB  
Review
West Nile Virus: An Update on Pathobiology, Epidemiology, Diagnostics, Control and “One Health” Implications
by Gervais Habarugira, Willy W. Suen, Jody Hobson-Peters, Roy A. Hall and Helle Bielefeldt-Ohmann
Pathogens 2020, 9(7), 589; https://doi.org/10.3390/pathogens9070589 - 19 Jul 2020
Cited by 92 | Viewed by 15076
Abstract
West Nile virus (WNV) is an important zoonotic flavivirus responsible for mild fever to severe, lethal neuroinvasive disease in humans, horses, birds, and other wildlife species. Since its discovery, WNV has caused multiple human and animal disease outbreaks in all continents, except Antarctica. [...] Read more.
West Nile virus (WNV) is an important zoonotic flavivirus responsible for mild fever to severe, lethal neuroinvasive disease in humans, horses, birds, and other wildlife species. Since its discovery, WNV has caused multiple human and animal disease outbreaks in all continents, except Antarctica. Infections are associated with economic losses, mainly due to the cost of treatment of infected patients, control programmes, and loss of animals and animal products. The pathogenesis of WNV has been extensively investigated in natural hosts as well as in several animal models, including rodents, lagomorphs, birds, and reptiles. However, most of the proposed pathogenesis hypotheses remain contentious, and much remains to be elucidated. At the same time, the unavailability of specific antiviral treatment or effective and safe vaccines contribute to the perpetuation of the disease and regular occurrence of outbreaks in both endemic and non-endemic areas. Moreover, globalisation and climate change are also important drivers of the emergence and re-emergence of the virus and disease. Here, we give an update of the pathobiology, epidemiology, diagnostics, control, and “One Health” implications of WNV infection and disease. Full article
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13 pages, 970 KiB  
Article
Identification of Antimicrobial Resistance-Associated Genes through Whole Genome Sequencing of Mycoplasma bovis Isolates with Different Antimicrobial Resistances
by Lisa Ledger, Jason Eidt and Hugh Y. Cai
Pathogens 2020, 9(7), 588; https://doi.org/10.3390/pathogens9070588 - 19 Jul 2020
Cited by 8 | Viewed by 3744
Abstract
Antimicrobial resistance (AMR) in Mycoplasma bovis has been previously associated with topoisomerase and ribosomal gene mutations rather than specific resistance-conferring genes. Using whole genome sequencing (WGS) to identify potential new AMR mechanisms for M. bovis, it was found that a 2019 clinical isolate [...] Read more.
Antimicrobial resistance (AMR) in Mycoplasma bovis has been previously associated with topoisomerase and ribosomal gene mutations rather than specific resistance-conferring genes. Using whole genome sequencing (WGS) to identify potential new AMR mechanisms for M. bovis, it was found that a 2019 clinical isolate with high MIC (2019-043682) for fluoroquinolones, macrolides, lincosamides, pleuromutilins and tetracyclines had a new core genome multilocus sequencing (cgMLST) type (ST10-like) and 91% sequence similarity to the published genome of M. bovis PG45. Closely related to PG45, a 1982 isolate (1982-M6152) shared the same cgMLST type (ST17), 97.2% sequence similarity and low MIC results. Known and potential AMR- associated genetic events were identified through multiple sequence alignment of the three genomes. Isolate 2019-043682 had 507 genes with non-synonymous mutations (NSMs) and 67 genes disrupted. Isolate 1982-M6152 had 81 NSMs and 20 disruptions. Using functional roles and known mechanisms of antimicrobials, a 55 gene subset was assessed for AMR potential. Seventeen were previously identified from other bacteria as sites of AMR mutation, 38 shared similar functions to them, and 11 contained gene-disrupting mutations. This study indicated that M. bovis may obtain high AMR characteristics by mutating or disrupting other functional genes, in addition to topoisomerases and ribosomal genes. Full article
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16 pages, 2346 KiB  
Article
Modulation of Leptin and Leptin Receptor Expression in Mice Acutely Infected with Neospora caninum
by Luzia Teixeira, Alexandra Correia, Bárbara M. Oliveira, Ana Pinto, Paula G. Ferreira and Manuel Vilanova
Pathogens 2020, 9(7), 587; https://doi.org/10.3390/pathogens9070587 - 17 Jul 2020
Cited by 3 | Viewed by 2612
Abstract
Neospora caninum is an apicomplexan parasite that in cattle assumes particular importance, as it is responsible for abortions reported worldwide. Leptin is an adipokine mainly secreted by adipocytes, which beside its role in maintaining metabolic homeostasis also has important effects in both innate [...] Read more.
Neospora caninum is an apicomplexan parasite that in cattle assumes particular importance, as it is responsible for abortions reported worldwide. Leptin is an adipokine mainly secreted by adipocytes, which beside its role in maintaining metabolic homeostasis also has important effects in both innate and adaptive immunity. In previous work, we showed that mice chronically infected with N. caninum had elevated serum leptin levels. Here, we sought to assess whether acute infection with N. caninum infection influenced the production of this adipokine as well as leptin receptor mRNA levels. Our results show that acute infection with N. caninum led to decreased leptin serum levels and mRNA expression in adipose tissue. A decrease in leptin receptor transcript variant 1 mRNA (long isoform) and leptin receptor transcript variant 3 mRNA (one of the short isoforms) expression was also observed. An increase in the number of cells staining positive for leptin in the liver of infected mice was observed, although this increase was less marked in Interleukin (IL)-12/IL-23 p40-deficient mice. Overall, our results show that N. caninum infection also influences leptin production during acute infection. Full article
(This article belongs to the Special Issue Neospora Caninum: Infection and Immunity)
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13 pages, 1936 KiB  
Article
Stenamoeba dejonckheerei sp. nov., a Free-Living Amoeba Isolated from a Thermal Spring
by Manuel Alejandro Borquez-Román, Luis Fernando Lares-Jiménez, Libia Zulema Rodriguez-Anaya, Jose Reyes Gonzalez-Galaviz, Paul A. Fuerst, José Cuauhtémoc Ibarra-Gámez, Ramón Casillas-Hernández and Fernando Lares-Villa
Pathogens 2020, 9(7), 586; https://doi.org/10.3390/pathogens9070586 - 17 Jul 2020
Cited by 7 | Viewed by 2784
Abstract
Two amoeboid organisms were obtained from water samples taken from a thermal spring, "Agua Caliente", in Northwestern Mexico. The isolates were obtained when samples were cultivated at 37 °C on non-nutrient agar coated with Escherichia coli. The initial identification of the isolates was [...] Read more.
Two amoeboid organisms were obtained from water samples taken from a thermal spring, "Agua Caliente", in Northwestern Mexico. The isolates were obtained when samples were cultivated at 37 °C on non-nutrient agar coated with Escherichia coli. The initial identification of the isolates was performed morphologically using light microscopy. The samples were found to have trophozoite morphology consistent with members of the genus Stenamoeba, a genus derived in 2007 from within the abolished polyphyletic genus Platyamoeba. Further analysis was performed by sequencing PCR products obtained using universal eukaryotic primers for the small subunit ribosomal ribonucleic acid (SSU rRNA) gene. Sequencing primers were designed to allow the comparison of the 18S rRNA gene sequences of the new isolates with previous sequences reported for Stenamoeba. Phylogenetic relationships among sequences from Stenamoeba were determined using Maximum Likelihood analysis. The results showed the two "Agua Caliente" sequences to be closely related, while clearly separating them from those of other Stenamoeba taxa. The degrees of sequence differentiation from other taxa were considered sufficient to allow us to propose that the Mexican isolates represent a new species. Full article
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13 pages, 2364 KiB  
Communication
Scientometrics Approach to Research in Ovine Mastitis from 1970 to 2019 (with a Complete List of Relevant Literature References)
by Daphne T. Lianou and George C. Fthenakis
Pathogens 2020, 9(7), 585; https://doi.org/10.3390/pathogens9070585 - 17 Jul 2020
Cited by 13 | Viewed by 2608
Abstract
The present study is a scientometrics evaluation of refereed publications on bacterial mastitis in sheep; the objectives were the evaluation of the relevant papers and the presentation of quantitative characteristics regarding their scientific content and bibliometric details. The Web of Science platform was [...] Read more.
The present study is a scientometrics evaluation of refereed publications on bacterial mastitis in sheep; the objectives were the evaluation of the relevant papers and the presentation of quantitative characteristics regarding their scientific content and bibliometric details. The Web of Science platform was used with search terms: [mastitis OR *mammary infection*] AND [sheep OR ewe* OR ovine] for papers from 1970 tο 2019; only ‘articles’, ‘reviews’, ‘proceedings papers’, or ‘data papers’ were evaluated, whilst documents related solely to contagious agalactia, mammary aspects of lentiviral infections, or infections of the teats and the udder skin were excluded. Finally, 580 papers were considered in detail. The number of published papers increased from 8 during the 1970s to 273 during the 2010s. These papers originated from 43 countries (most from Greece or Spain, n = 87 from each) and 240 institutions (145 universities and 95 other establishments), of which 35 produced ≥ 5 papers each. Most papers present original studies (n = 539) with a few reviews (n = 41). The original papers refer to dairy (n = 428), meat (n = 113), or wool (n = 1) production systems and present field (n = 329), laboratory (n = 163), or experimental (n = 67) work; the papers report aetiology (n = 146), risk factors (n = 100), pathogenesis (n = 92), diagnosis (n = 88), effects (n = 66), treatment (n = 50), control (n = 36), or descriptive epidemiology (n = 32) of the disease. Papers related to dairy production present more field and fewer experimental work than papers related to meat production; also, in papers describing work performed in dairy sheep, studies about aetiology, risk factors, and diagnosis of the disease predominate, whilst in papers performed in meat sheep, studies about aetiology, pathogenesis, and effects/diagnosis are reported more often. The papers were published in 175 scientific journals (most in Small Ruminant Research, n = 90, or Journal of Dairy Science, n = 54). On average, the papers received 16.8 total citations and 1.6 yearly citations (h-index = 47). Most papers were published in Scimago classification Q1 (n = 240) or Q2 (n = 230) journals and received 23.4 or 15.4 total citations, respectively. Reviews received more citations than original papers; among the latter, papers with work referring to dairy production received more yearly citations than papers referring to meat production; no differences in citations were seen according to type of work or mastitis aspect covered. Most citations were received by papers from France. Papers published in Journal of Dairy Science or Small Ruminant Research received the most citations. In total, there were 1558 individual authors of the papers, with 24 authors having co-authored > 10 papers each (max: 73 papers); on average, there were 5.2 co-authors per paper (min–max: 1–25). Average number of co-authors progressively increased from 2.1 in the 1970s to 6.3 in the 2010s, with original papers having a higher number of co-authors than reviews: 5.3 and 3.7, respectively. Papers from France had highers number of co-authors (7.9). The findings of this first ever scientometrics study into ovine mastitis indicate that the disease has not been studied as other sheep diseases and that future studies in it should be directed to its control. Full article
(This article belongs to the Collection Mastitis in Dairy Ruminants)
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12 pages, 2578 KiB  
Article
Polymorphism and Selection Pressure of SARS-CoV-2 Vaccine and Diagnostic Antigens: Implications for Immune Evasion and Serologic Diagnostic Performance
by Eric Dumonteil and Claudia Herrera
Pathogens 2020, 9(7), 584; https://doi.org/10.3390/pathogens9070584 - 17 Jul 2020
Cited by 11 | Viewed by 4564
Abstract
The ongoing SARS-CoV-2 pandemic has triggered multiple efforts for serological tests and vaccine development. Most of these tests and vaccines are based on the Spike glycoprotein (S) or the Nucleocapsid (N) viral protein. Conservation of these antigens among viral strains is critical to [...] Read more.
The ongoing SARS-CoV-2 pandemic has triggered multiple efforts for serological tests and vaccine development. Most of these tests and vaccines are based on the Spike glycoprotein (S) or the Nucleocapsid (N) viral protein. Conservation of these antigens among viral strains is critical to ensure optimum diagnostic test performance and broad protective efficacy, respectively. We assessed N and S antigen diversity from 17,853 SARS-CoV-2 genome sequences and evaluated selection pressure. Up to 6–7 incipient phylogenetic clades were identified for both antigens, confirming early variants of the S antigen and identifying new ones. Significant diversifying selection was detected at multiple sites for both antigens. Some sequence variants have already spread in multiple regions, in spite of their low frequency. In conclusion, the N and S antigens of SARS-CoV-2 are well-conserved antigens, but new clades are emerging and may need to be included in future diagnostic and vaccine formulations. Full article
(This article belongs to the Section Human Pathogens)
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5 pages, 1495 KiB  
Case Report
Bovine Papillomatosis Hiding a Zoonotic Infection: Epitheliotropic Viruses in Bovine Skin Lesions
by Laura Gallina, Federica Savini, Sabrina Canziani, Matteo Frasnelli, Antonio Lavazza, Alessandra Scagliarini and Davide Lelli
Pathogens 2020, 9(7), 583; https://doi.org/10.3390/pathogens9070583 - 17 Jul 2020
Cited by 5 | Viewed by 4068
Abstract
We describe two cases of skin co-infections with epitheliotropic viruses, detected in two cattle during lumpy skin disease (LSD) surveillance in northern Italy. A diagnostic protocol including different molecular methods as well as negative staining electron microscopy was applied to detect the most [...] Read more.
We describe two cases of skin co-infections with epitheliotropic viruses, detected in two cattle during lumpy skin disease (LSD) surveillance in northern Italy. A diagnostic protocol including different molecular methods as well as negative staining electron microscopy was applied to detect the most common viral agents belonging to the family Papillomaviridae, Poxviridae and Herpesviridae which cause skin diseases in cattle. Two specimens were collected from cases clinically diagnosed as papillomatosis and pseudo-LSD. Both skin lesions were shown to harbor more than one viral species. This case report shows, for the first time, co-infection of zoonotic parapoxvirus with bovine papillomavirus and herpesvirus in skin lesions of cattle. In particular, the simultaneous presence of virions morphologically referable to parapoxvirus and papillomavirus confirms that the replication of both viruses in the same lesion can happen and the so-called papillomatosis can bear zoonotic viruses. Full article
(This article belongs to the Special Issue Bovine Papillomavirus Infection)
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13 pages, 1025 KiB  
Article
Molecular Characterization of African Swine Fever Virus Isolates in Estonia in 2014–2019
by Annika Vilem, Imbi Nurmoja, Tarmo Niine, Taavi Riit, Raquel Nieto, Arvo Viltrop and Carmina Gallardo
Pathogens 2020, 9(7), 582; https://doi.org/10.3390/pathogens9070582 - 17 Jul 2020
Cited by 28 | Viewed by 3980
Abstract
After the extensive spread of the African swine fever virus (ASFV) genotype II in Eastern Europe, the first case of African swine fever (ASF) in Estonia was diagnosed in September 2014. By the end of 2019, 3971 ASFV-positive wild boars were found, and [...] Read more.
After the extensive spread of the African swine fever virus (ASFV) genotype II in Eastern Europe, the first case of African swine fever (ASF) in Estonia was diagnosed in September 2014. By the end of 2019, 3971 ASFV-positive wild boars were found, and 27 domestic pig outbreaks were reported. A selection of ASFV isolates from wild boar and domestic pigs (during the period of September 2014–2019) was molecularly characterized using standardized genotyping procedures. One of the proven markers to characterize this virus is the central variable region (CVR) within the B602L gene. In summer 2015, a new ASFV genotype II CVR variant 2 (GII-CVR2) was confirmed in Estonia. The results suggest that the GII-CVR2 variant was only confirmed in wild boar from a limited area in southern Estonia in 2015 and 2016. In addition to GII-CVR2, a single nucleotide polymorphism (SNP) that resulted in amino acid change was identified within the genotype II CVR variant 1 (GII-CVR1). The GII-CVR1/SNP1 strain was isolated in Estonia in November 2016. Additional GII-CVR1/SNP1 cases were confirmed in two neighbouring counties, as well as in one outbreak farm in June 2017. Based on the available data, no GII-CVR2 and GII-CVR1/SNP1 have been reported by other affected European countries. The spread of variant strains in Estonia has been limited over time, and restricted to a relatively small area. Full article
(This article belongs to the Special Issue African Swine Fever Virus Infection)
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13 pages, 955 KiB  
Review
Contributions of Mass Spectrometry-Based Proteomics to Understanding Salmonella-Host Interactions
by Buyu Zhang, Bohao Liu, Yinglin Zhou, Xinxiang Zhang, Qinghua Zou and Xiaoyun Liu
Pathogens 2020, 9(7), 581; https://doi.org/10.3390/pathogens9070581 - 17 Jul 2020
Cited by 5 | Viewed by 3582
Abstract
As a model pathogen, Salmonella invades both phagocytic and non-phagocytic host cells and adopts an intracellular lifestyle in a membrane-bound compartment during infection. Therefore, a systemic overview of Salmonella adaptations to distinct host cells together with host remodeling will assist us in charting [...] Read more.
As a model pathogen, Salmonella invades both phagocytic and non-phagocytic host cells and adopts an intracellular lifestyle in a membrane-bound compartment during infection. Therefore, a systemic overview of Salmonella adaptations to distinct host cells together with host remodeling will assist us in charting the landscape of host-pathogen interactions. Central to the Salmonella-host interplay are bacterial virulence factors (effectors) that are injected into host cells by type III secretion systems (T3SSs). Despite great progress, functional studies of bacterial effectors have experienced daunting challenges as well. In the last decade, mass spectrometry-based proteomics has evolved into a powerful technological platform that can quantitatively measure thousands of proteins in terms of their expression as well as post-translational modifications. Here, we will review the applications of high-throughput proteomic technologies in understanding the dynamic reprogramming of both Salmonella and host proteomes during the course of infection. Furthermore, we will summarize the progress in utilizing affinity purification-mass spectrometry to screen for host substrates of Salmonella T3SS effectors. Finally, we will critically discuss some limitations/challenges with current proteomic platforms in the context of host-pathogen interactions and highlight some emerging technologies that may offer the promise of tackling these problems. Full article
(This article belongs to the Special Issue Salmonella Persistent Infections)
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14 pages, 4534 KiB  
Article
Genetic Diversity Among SARS-CoV2 Strains in South America may Impact Performance of Molecular Detection
by Juan David Ramírez, Marina Muñoz, Carolina Hernández, Carolina Flórez, Sergio Gomez, Angelica Rico, Lisseth Pardo, Esther C. Barros and Alberto E. Paniz-Mondolfi
Pathogens 2020, 9(7), 580; https://doi.org/10.3390/pathogens9070580 - 17 Jul 2020
Cited by 30 | Viewed by 6463
Abstract
Since its emergence in Wuhan (China) on December 2019, the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has rapidly spread worldwide. After its arrival in South America in February 2020, the virus has expanded throughout the region, infecting over 900,000 individuals with approximately [...] Read more.
Since its emergence in Wuhan (China) on December 2019, the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has rapidly spread worldwide. After its arrival in South America in February 2020, the virus has expanded throughout the region, infecting over 900,000 individuals with approximately 41,000 reported deaths to date. In response to the rapidly growing number of cases, a number of different primer-probe sets have been developed. However, despite being highly specific, most of these primer-probe sets are known to exhibit variable sensitivity. Currently, there are more than 300 SARS-CoV2 whole genome sequences deposited in databases from Brazil, Chile, Ecuador, Colombia, Uruguay, Peru, and Argentina. To test how regional viral diversity may impact oligo binding sites and affect test performance, we reviewed all available primer-probe sets targeting the E, N, and RdRp genes against available South American SARS-CoV-2 genomes checking for nucleotide variations in annealing sites. Results from this in silico analysis showed no nucleotide variations on the E-gene target region, in contrast to the N and RdRp genes which showed massive nucleotide variations within oligo binding sites. In lines with previous data, our results suggest that the E-gene stands as the most conserved and reliable target when considering single-gene target testing for molecular diagnosis of SARS-CoV-2 in South America. Full article
(This article belongs to the Collection SARS-CoV Infections)
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20 pages, 17315 KiB  
Article
Pichinde Virus Infection of Outbred Hartley Guinea Pigs as a Surrogate Animal Model for Human Lassa Fever: Histopathological and Immunohistochemical Analyses
by Wun-Ju Shieh, Shuiyun Lan, Sherif R. Zaki, Hinh Ly and Yuying Liang
Pathogens 2020, 9(7), 579; https://doi.org/10.3390/pathogens9070579 - 16 Jul 2020
Cited by 7 | Viewed by 3495
Abstract
Lassa virus (LASV) is a mammarenavirus (arenavirus) that causes zoonotic infection in humans that can lead to fatal hemorrhagic Lassa fever (LF) disease. Currently, there are no FDA-approved vaccines or therapeutics against LASV. Development of treatments against LF and other related arenavirus-induced hemorrhagic [...] Read more.
Lassa virus (LASV) is a mammarenavirus (arenavirus) that causes zoonotic infection in humans that can lead to fatal hemorrhagic Lassa fever (LF) disease. Currently, there are no FDA-approved vaccines or therapeutics against LASV. Development of treatments against LF and other related arenavirus-induced hemorrhagic fevers (AHFs) requires relevant animal models that can recapitulate clinical and pathological features of AHF diseases in humans. Laboratory mice are generally resistant to LASV infection, and non-human primates, while being a good animal model for LF, are limited by their high cost. Here, we describe a small, affordable, and convenient animal model that is based on outbred Hartley guinea pigs infected with Pichinde virus (PICV), a mammarenavirus that is non-pathogenic in humans, for use as a surrogate model of human LF. We conducted a detailed analysis of tissue histopathology and immunohistochemical analysis of different organs of outbred Hartley guinea pigs infected with different PICV strains that show differential disease phenotypes and pathologies. Comparing to infection with the avirulent PICV strain (P2 or rP2), animals infected with the virulent strain (P18 or rP18) show extensive pathological changes in different organs that sustain high levels of virus replication. The similarity of tissue pathology and viral antigen distribution between the virulent PICV–guinea pig model and lethal human LASV infection supports a role of this small animal model as a surrogate model of studying human LF in order to understand its pathogenesis and for evaluating potential preventative and therapeutic options against AHFs. Full article
(This article belongs to the Special Issue Comparative Animal Models of Human Viral Infections)
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18 pages, 1877 KiB  
Article
Prevalence of Infectious Spleen and Kidney Necrosis Virus (ISKNV), Nervous Necrosis Virus (NNV) and Ectoparasites in Juvenile Epinephelus spp. Farmed in Aceh, Indonesia
by Bakhtiar Sah Putra, Paul M. Hick, Evelyn Hall, Richard J. Whittington, Razi Khairul, Evarianti, Nurbariah and Joy A. Becker
Pathogens 2020, 9(7), 578; https://doi.org/10.3390/pathogens9070578 - 16 Jul 2020
Cited by 11 | Viewed by 4205
Abstract
A cross-sectional survey was used to estimate the prevalence of infections with the Infectious spleen and kidney necrosis virus (ISKNV, Megalocytivirus), nervous necrosis virus (NNV, Betanodavirus), and infestations with ectoparasites during the rainy season in juvenile grouper (Epinephelus spp.) farmed [...] Read more.
A cross-sectional survey was used to estimate the prevalence of infections with the Infectious spleen and kidney necrosis virus (ISKNV, Megalocytivirus), nervous necrosis virus (NNV, Betanodavirus), and infestations with ectoparasites during the rainy season in juvenile grouper (Epinephelus spp.) farmed in Aceh, Indonesia. The survey was intended to detect aquatic pathogens present at 10% prevalence with 95% confidence, assuming 100% sensitivity and specificity using a sample size of 30 for each diagnostic test. Eight populations of grouper from seven farms were sampled. Additional targeted sampling was conducted for populations experiencing high mortality. Infection with NNV was detected at all farms with seven of the eight populations being positive. The apparent prevalence for NNV ranged from 0% (95% CI: 0–12) to 73% (95% CI: 54–88). All of the fish tested from the targeted samples (Populations 9 and 10) were positive for NNV and all had vacuolation of the brain and retina consistent with viral nervous necrosis (VNN). Coinfections with ISKNV were detected in five populations, with the highest apparent prevalence being 13% (95% CI: 4–31%). Trichodina sp., Cryptocaryon irritans and Gyrodactylus sp. were detected at three farms, with 66% to 100% of fish being infested. Hybrid grouper sourced from a hatchery were 5.4 and 24.9 times more likely to have a NNV infection and a higher parasite load compared to orange-spotted grouper collected from the wild (p < 0.001). This study found that VNN remains a high-impact disease in grouper nurseries in Aceh, Indonesia. Full article
(This article belongs to the Special Issue Emerging Infectious Diseases in Aquaculture)
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19 pages, 12487 KiB  
Article
Polycystic Kidney Disease Ryanodine Receptor Domain (PKDRR) Proteins in Oomycetes
by Limian Zheng, Barbara Doyle Prestwich, Patrick T. Harrison and John J. Mackrill
Pathogens 2020, 9(7), 577; https://doi.org/10.3390/pathogens9070577 - 16 Jul 2020
Cited by 1 | Viewed by 2647
Abstract
In eukaryotes, two sources of Ca2+ are accessed to allow rapid changes in the cytosolic levels of this second messenger: the extracellular medium and intracellular Ca2+ stores, such as the endoplasmic reticulum. One class of channel that permits Ca2+ entry [...] Read more.
In eukaryotes, two sources of Ca2+ are accessed to allow rapid changes in the cytosolic levels of this second messenger: the extracellular medium and intracellular Ca2+ stores, such as the endoplasmic reticulum. One class of channel that permits Ca2+ entry is the transient receptor potential (TRP) superfamily, including the polycystic kidney disease (PKD) proteins, or polycystins. Channels that release Ca2+ from intracellular stores include the inositol 1,4,5-trisphosphate/ryanodine receptor (ITPR/RyR) superfamily. Here, we characterise a family of proteins that are only encoded by oomycete genomes, that we have named PKDRR, since they share domains with both PKD and RyR channels. We provide evidence that these proteins belong to the TRP superfamily and are distinct from the ITPR/RyR superfamily in terms of their evolutionary relationships, protein domain architectures and predicted ion channel structures. We also demonstrate that a hypothetical PKDRR protein from Phytophthora infestans is produced by this organism, is located in the cell-surface membrane and forms multimeric protein complexes. Efforts to functionally characterise this protein in a heterologous expression system were unsuccessful but support a cell-surface localisation. These PKDRR proteins represent potential targets for the development of new “fungicides”, since they are of a distinctive structure that is only found in oomycetes and not in any other cellular organisms. Full article
(This article belongs to the Special Issue Biology and Pathology of Phytophthora infestans)
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16 pages, 1411 KiB  
Article
Molecular Detection and Genetic Diversity of Toxoplasma gondii Oocysts in Cat Faeces from Klang Valley, Malaysia, Using B1 and REP Genes in 2018
by Mohammed Nasiru Wana, Mohamad Aris Mohd Moklas, Malaika Watanabe, Ngah Zasmy Unyah, Sharif Alhassan Abdullahi, Ashraf Ahmad Issa Alapid, Norshariza Nordin, Rusliza Basir and Roslaini Abd Majid
Pathogens 2020, 9(7), 576; https://doi.org/10.3390/pathogens9070576 - 16 Jul 2020
Cited by 17 | Viewed by 3736
Abstract
The major route for Toxoplasma gondii (T. gondii) infection is through the ingestion of foods contaminated with oocyst from cat faeces. The microscopic detection of T. gondii oocysts in cat faeces is challenging, which contributes to the failure of detecting or [...] Read more.
The major route for Toxoplasma gondii (T. gondii) infection is through the ingestion of foods contaminated with oocyst from cat faeces. The microscopic detection of T. gondii oocysts in cat faeces is challenging, which contributes to the failure of detecting or differentiating it from other related coccidian parasites. This study aims to detect T. gondii oocysts in cat faeces using two multicopy-target PCR assays and to evaluate their genetic diversity. Cat faecal (200) samples were collected from pet cats (PCs; 100) and free-roaming cats (FRCs; 100) within Klang Valley, Malaysia, and screened for coccidian oocysts by microscopy using Sheather’s sucrose floatation. PCR assays were performed on each faecal sample, targeting a B1 gene and a repetitive element (REP) gene to confirm T. gondii oocysts. Additionally, the PCR amplicons from the REP gene were sequenced to further confirm T. gondii-positive samples for phylogenetic analysis. Microscopy detected 7/200 (3.5%) T. gondii-like oocysts, while both the B1 gene and the REP gene detected 17/200 (8.5%) samples positive for T. gondii. All samples that were microscopically positive for T. gondii-like oocysts were also shown to be positive by both B1 and REP genes. The BLAST results sequenced for 16/200 (8.0%) PCR-positive T. gondii samples revealed homology and genetic heterogeneity with T. gondii strains in the GenBank, except for only one positive sample that did not show a result. There was almost perfect agreement (k = 0.145) between the two PCR assays targeting the B1 gene and the REP gene. This is the first report on microscopic, molecular detection and genetic diversity of T. gondii from cat faecal samples in Malaysia. In addition, the sensitivities of either the B1 gene or REP gene multicopy-target PCR assays are suitable for the accurate detection of T. gondii from cat faeces. Full article
(This article belongs to the Section Human Pathogens)
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17 pages, 1934 KiB  
Article
Vector Competence of Aedes aegypti, Aedes albopictus and Culex quinquefasciatus from Brazil and New Caledonia for Three Zika Virus Lineages
by Rosilainy S. Fernandes, Olivia O’Connor, Maria Ignez L. Bersot, Dominique Girault, Marguerite R. Dokunengo, Nicolas Pocquet, Myrielle Dupont-Rouzeyrol and Ricardo Lourenço-de-Oliveira
Pathogens 2020, 9(7), 575; https://doi.org/10.3390/pathogens9070575 - 16 Jul 2020
Cited by 18 | Viewed by 3509
Abstract
Zika virus (ZIKV) has caused severe epidemics in South America beginning in 2015, following its spread through the Pacific. We comparatively assessed the vector competence of ten populations of Aedes aegypti and Ae. albopictus from Brazil and two of Ae. aegypti and one [...] Read more.
Zika virus (ZIKV) has caused severe epidemics in South America beginning in 2015, following its spread through the Pacific. We comparatively assessed the vector competence of ten populations of Aedes aegypti and Ae. albopictus from Brazil and two of Ae. aegypti and one of Culex quinquefasciatus from New Caledonia to transmit three ZIKV isolates belonging to African, Asian and American lineages. Recently colonized mosquitoes from eight distinct sites from both countries were orally challenged with the same viral load (107 TCID50/mL) and examined after 7, 14 and 21 days. Cx. quinquefasciatus was refractory to infection with all virus strains. In contrast, although competence varied with geographical origin, Brazilian and New Caledonian Ae. aegypti could transmit the three ZIKV lineages, with a strong advantage for the African lineage (the only one reaching saliva one-week after challenge). Brazilian Ae. albopictus populations were less competent than Ae. aegypti populations. Ae. albopictus generally exhibited almost no transmission for Asian and American lineages, but was efficient in transmitting the African ZIKV. Viral surveillance and mosquito control measures must be strengthened to avoid the spread of new ZIKV lineages and minimize the transmission of viruses currently circulating. Full article
(This article belongs to the Special Issue Untargeted Alternative Routes of Arbovirus Transmission)
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2 pages, 181 KiB  
Erratum
Erratum: Fukuyama, K., et al. Evaluation of the Immunomodulatory Ability of Lactic Acid Bacteria Isolated from Feedlot Cattle Against Mastitis Using a Bovine Mammary Epithelial Cells In Vitro Assay. Pathogens 2020, 9, 410
by Kohtaro Fukuyama, Md. Aminul Islam, Michihiro Takagi, Wakako Ikeda-Ohtsubo, Shoichiro Kurata, Hisashi Aso, Maria Elena Fatima Nader-Macías, Graciela Vignolo, Julio Villena and Haruki Kitazawa
Pathogens 2020, 9(7), 574; https://doi.org/10.3390/pathogens9070574 - 16 Jul 2020
Cited by 5 | Viewed by 2136
Abstract
The authors would like to make the following corrections about the published paper [...] Full article
(This article belongs to the Collection Mastitis in Dairy Ruminants)
4 pages, 209 KiB  
Editorial
Leptospira Infections in Domestic and Wild Animals
by Giovanni Cilia, Fabrizio Bertelloni and Filippo Fratini
Pathogens 2020, 9(7), 573; https://doi.org/10.3390/pathogens9070573 - 15 Jul 2020
Cited by 28 | Viewed by 3864
Abstract
Leptospirosis is a worldwide-distributed, re-emerging zoonosis due to the large variety of wild and domestic animal species that can play the role of natural or accidental host. Currently, specific animal species play an important role as the reservoir for particular Leptospira serovars, although [...] Read more.
Leptospirosis is a worldwide-distributed, re-emerging zoonosis due to the large variety of wild and domestic animal species that can play the role of natural or accidental host. Currently, specific animal species play an important role as the reservoir for particular Leptospira serovars, although recent investigations have highlighted new host–pathogen interactions involved in Leptospira epidemiology. Furthermore, the constant modification of ecosystems and wildlife habitats and the constantly increasing number of animal species moving towards urban or peri-urban areas are increasing the possibility of direct or indirect contacts between wildlife and domestic animals; furthermore, the constant modification of animal leptospirosis also causes problems for human health. The studies published in this Special Issue have evidenced and confirmed the hidden role of a large variety of animal species, domestic and wild, in the leptospirosis epidemiology. They highlighted the necessity for continuous monitoring and large-scale surveillance studies to better understand this neglected and re-emerging zoonosis. Full article
(This article belongs to the Special Issue Leptospira infections in Domestic and Wild Animal)
12 pages, 1235 KiB  
Article
Frequent Recombination Events in Leishmania donovani: Mining Population Data
by Igor B. Rogozin, Arzuv Charyyeva, Ivan A. Sidorenko, Vladimir N. Babenko and Vyacheslav Yurchenko
Pathogens 2020, 9(7), 572; https://doi.org/10.3390/pathogens9070572 - 15 Jul 2020
Cited by 5 | Viewed by 2550
Abstract
The Leishmania donovani species complex consists of all L. donovani and L. infantum strains mainly responsible for visceral leishmaniasis (VL). It was suggested that genome rearrangements in Leishmania spp. occur very often, thus enabling parasites to adapt to the different environmental conditions. Some [...] Read more.
The Leishmania donovani species complex consists of all L. donovani and L. infantum strains mainly responsible for visceral leishmaniasis (VL). It was suggested that genome rearrangements in Leishmania spp. occur very often, thus enabling parasites to adapt to the different environmental conditions. Some of these rearrangements may be directly linked to the virulence or explain the reduced efficacy of antimonial drugs in some isolates. In the current study, we focused on a large-scale analysis of putative gene conversion events using publicly available datasets. Previous population study of L. donovani suggested that population variability of L. donovani is relatively low, however the authors used masking procedures and strict read selection criteria. We decided to re-analyze DNA-seq data without masking sequences, because we were interested in the most dynamic fraction of the genome. The majority of samples have an excess of putative gene conversion/recombination events in the noncoding regions, however we found an overall excess of putative intrachromosomal gene conversion/recombination in the protein coding genes, compared to putative interchromosomal gene conversion/recombination events. Full article
(This article belongs to the Special Issue Kinetoplastid Phylogenomics and Evolution)
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13 pages, 3654 KiB  
Article
Intracellular Growth and Cell Cycle Progression are Dependent on (p)ppGpp Synthetase/Hydrolase in Brucella abortus
by Mathilde Van der Henst, Elodie Carlier and Xavier De Bolle
Pathogens 2020, 9(7), 571; https://doi.org/10.3390/pathogens9070571 - 14 Jul 2020
Cited by 5 | Viewed by 2905
Abstract
Brucella abortus is a pathogenic bacterium able to proliferate inside host cells. During the first steps of its trafficking, it is able to block the progression of its cell cycle, remaining at the G1 stage for several hours, before it reaches its replication [...] Read more.
Brucella abortus is a pathogenic bacterium able to proliferate inside host cells. During the first steps of its trafficking, it is able to block the progression of its cell cycle, remaining at the G1 stage for several hours, before it reaches its replication niche. We hypothesized that starvation mediated by guanosine tetra- or penta-phosphate, (p)ppGpp, could be involved in the cell cycle arrest. Rsh is the (p)ppGpp synthetase/hydrolase. A B. abortusrsh mutant is unable to grow in minimal medium, it is unable to survive in stationary phase in rich medium and it is unable to proliferate inside RAW 264.7 macrophages. A strain producing the heterologous constitutive (p)ppGpp hydrolase Mesh1b is also unable to proliferate inside these macrophages. Altogether, these data suggest that (p)ppGpp is necessary to allow B. abortus to adapt to its intracellular growth conditions. The deletion of dksA, proposed to mediate a part of the effect of (p)ppGpp on transcription, does not affect B. abortus growth in culture or inside macrophages. Expression of a gene coding for a constitutively active (p)ppGpp synthetase slows down growth in rich medium and inside macrophages. Using an mCherry–ParB fusion able to bind to the replication origin of the main chromosome of B. abortus, we observed that expression of the constitutive (p)ppGpp synthetase gene generates an accumulation of bacteria at the G1 phase. We thus propose that (p)ppGpp accumulation could be one of the factors contributing to the G1 arrest observed for B. abortus in RAW 264.7 macrophages. Full article
(This article belongs to the Special Issue Host Immune Responses and Pathogenesis to Brucella spp. Infection)
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17 pages, 42573 KiB  
Article
Phylogenetic Analyses of Rotavirus A from Cattle in Uruguay Reveal the Circulation of Common and Uncommon Genotypes and Suggest Interspecies Transmission
by Matías Castells, Rubén Darío Caffarena, María Laura Casaux, Carlos Schild, Samuel Miño, Felipe Castells, Daniel Castells, Matías Victoria, Franklin Riet-Correa, Federico Giannitti, Viviana Parreño and Rodney Colina
Pathogens 2020, 9(7), 570; https://doi.org/10.3390/pathogens9070570 - 14 Jul 2020
Cited by 17 | Viewed by 3325
Abstract
Uruguay is one of the main exporters of beef and dairy products, and cattle production is one of the main economic sectors in this country. Rotavirus A (RVA) is the main pathogen associated with neonatal calf diarrhea (NCD), a syndrome that leads to [...] Read more.
Uruguay is one of the main exporters of beef and dairy products, and cattle production is one of the main economic sectors in this country. Rotavirus A (RVA) is the main pathogen associated with neonatal calf diarrhea (NCD), a syndrome that leads to significant economic losses to the livestock industry. The aims of this study are to determine the frequency of RVA infections, and to analyze the genetic diversity of RVA strains in calves in Uruguay. A total of 833 samples from dairy and beef calves were analyzed through RT-qPCR and sequencing. RVA was detected in 57.0% of the samples. The frequency of detection was significantly higher in dairy (59.5%) than beef (28.4%) calves (p < 0.001), while it did not differ significantly among calves born in herds that were vaccinated (64.0%) or not vaccinated (66.7%) against NCD. The frequency of RVA detection and the viral load were significantly higher in samples from diarrheic (72.1%, 7.99 log10 genome copies/mL of feces) than non-diarrheic (59.9%, 7.35 log10 genome copies/mL of feces) calves (p < 0.005 and p = 0.007, respectively). The observed G-types (VP7) were G6 (77.6%), G10 (20.7%), and G24 (1.7%), while the P-types were P[5] (28.4%), P[11] (70.7%), and P[33] (0.9%). The G-type and P-type combinations were G6P[11] (40.4%), G6P[5] (38.6%), G10P[11] (19.3%), and the uncommon genotype G24P[33] (1.8%). VP6 and NSP1-5 genotyping were performed to better characterize some strains. The phylogenetic analyses suggested interspecies transmission, including transmission between animals and humans. Full article
(This article belongs to the Special Issue Rotaviruses and Rotavirus Vaccines)
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15 pages, 1009 KiB  
Review
Microbial Etiology and Prevention of Dental Caries: Exploiting Natural Products to Inhibit Cariogenic Biofilms
by Xiuqin Chen, Eric Banan-Mwine Daliri, Namhyeon Kim, Jong-Rae Kim, Daesang Yoo and Deog-Hwan Oh
Pathogens 2020, 9(7), 569; https://doi.org/10.3390/pathogens9070569 - 14 Jul 2020
Cited by 136 | Viewed by 16878
Abstract
Dental caries is one of the most common microbe-mediated oral diseases in human beings. At present, the accepted etiology of caries is based on a four-factor theory that includes oral microorganisms, oral environment, host, and time. Excessive exposure to dietary carbohydrates leads to [...] Read more.
Dental caries is one of the most common microbe-mediated oral diseases in human beings. At present, the accepted etiology of caries is based on a four-factor theory that includes oral microorganisms, oral environment, host, and time. Excessive exposure to dietary carbohydrates leads to the accumulation of acid-producing and acid-resistant microorganisms in the mouth. Dental caries is driven by dysbiosis of the dental biofilm adherent to the enamel surface. Effective preventive methods include inhibiting the cariogenic microorganisms, treatment with an anti-biofilm agent, and sugar intake control. The goal is to reduce the total amount of biofilm or the levels of specific pathogens. Natural products could be recommended for preventing dental caries, since they may possess fewer side effects in comparison with synthetic antimicrobials. Herein, the mechanisms of oral microbial community development and functional specialization are discussed. We highlight the application of widely explored natural products in the last five years for their ability to inhibit cariogenic microorganisms. Full article
(This article belongs to the Special Issue Microbial Interactions during Infection)
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8 pages, 226 KiB  
Article
Seroprevalence of Hepatitis E Virus in Forestry Workers from Trentino-Alto Adige Region (Northern Italy)
by Marina Monini, Fabio Ostanello, Alessandra Dominicis, Valentina Tagliapietra, Gabriele Vaccari, Annapaola Rizzoli, Claudia M. Trombetta, Emanuele Montomoli and Ilaria Di Bartolo
Pathogens 2020, 9(7), 568; https://doi.org/10.3390/pathogens9070568 - 14 Jul 2020
Cited by 6 | Viewed by 2201
Abstract
People with some occupational or recreational activities, such as hunters and veterinarians, may have increased risk to be infected by the hepatitis E virus (HEV). The aim of the present study was to establish whether forestry workers could be considered at a higher [...] Read more.
People with some occupational or recreational activities, such as hunters and veterinarians, may have increased risk to be infected by the hepatitis E virus (HEV). The aim of the present study was to establish whether forestry workers could be considered at a higher risk of HEV infection than a control group. One hundred and fifty sera from forestry workers and a control group of 85 sera were analysed by anti-HEV IgG antibodies detection using a commercial ELISA kit. The anti-HEV IgG seroprevalence was 14% for forestry workers and 9.4% for the control group. Comparing the risk of HEV infection in the two groups, there was no difference in the odds ratio. However, the seroprevalence in older subjects was higher in the forestry workers than in the control group. Two sera from forestry workers were also positive for anti-HEV IgM, and, in one of them, HEV-RNA was detected. Our findings showed an increase of seroprevalence with age, which is likely to reflect cumulative exposure to HEV over time. The occupation of forestry workers did not seem to be associated with a higher risk of HEV infection. The study provided new insights into the risk of acquiring HEV in occupational exposure workers with open-air activities. Full article
(This article belongs to the Special Issue Hepatitis E Virus (HEV) Infections)
29 pages, 2943 KiB  
Article
Legionella Diversity and Spatiotemporal Variation in the Occurrence of Opportunistic Pathogens within a Large Building Water System
by Helen Y. Buse, Brian J. Morris, Vicente Gomez-Alvarez, Jeffrey G. Szabo and John S. Hall
Pathogens 2020, 9(7), 567; https://doi.org/10.3390/pathogens9070567 - 13 Jul 2020
Cited by 19 | Viewed by 3719
Abstract
Understanding Legionella survival mechanisms within building water systems (BWSs) is challenging due to varying engineering, operational, and water quality characteristics unique to each system. This study aimed to evaluate Legionella, mycobacteria, and free-living amoebae occurrence within a BWS over 18–28 months at [...] Read more.
Understanding Legionella survival mechanisms within building water systems (BWSs) is challenging due to varying engineering, operational, and water quality characteristics unique to each system. This study aimed to evaluate Legionella, mycobacteria, and free-living amoebae occurrence within a BWS over 18–28 months at six locations differing in plumbing material and potable water age, quality, and usage. A total of 114 bulk water and 57 biofilm samples were analyzed. Legionella culturability fluctuated seasonally with most culture-positive samples being collected during the winter compared to the spring, summer, and fall months. Positive and negative correlations between Legionella and L. pneumophila occurrence and other physiochemical and microbial water quality parameters varied between location and sample types. Whole genome sequencing of 19 presumptive Legionella isolates, from four locations across three time points, identified nine isolates as L. pneumophila serogroup (sg) 1 sequence-type (ST) 1; three as L. pneumophila sg5 ST1950 and ST2037; six as L. feeleii; and one as Ochrobactrum. Results showed the presence of a diverse Legionella population with consistent and sporadic occurrence at four and two locations, respectively. Viewed collectively with similar studies, this information will enable a better understanding of the engineering, operational, and water quality parameters supporting Legionella growth within BWSs. Full article
(This article belongs to the Special Issue Legionella Contamination in Water Environment)
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