Previous Issue

Table of Contents

Pathogens, Volume 8, Issue 1 (March 2019)

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
View options order results:
result details:
Displaying articles 1-23
Export citation of selected articles as:
Open AccessReview Helicobacter pylori-induced DNA Methylation as an Epigenetic Modulator of Gastric Cancer: Recent Outcomes and Future Direction
Received: 28 December 2018 / Revised: 4 February 2019 / Accepted: 11 February 2019 / Published: 13 February 2019
Viewed by 103 | PDF Full-text (239 KB) | HTML Full-text | XML Full-text
Abstract
Gastric cancer is ranked fifth in cancer list and has the third highest mortality rate. Helicobacter pylori is a class I carcinogen and a predominant etiological factor of gastric cancer. H. pylori infection may induce carcinogenesis via epigenetic alterations in the promoter region [...] Read more.
Gastric cancer is ranked fifth in cancer list and has the third highest mortality rate. Helicobacter pylori is a class I carcinogen and a predominant etiological factor of gastric cancer. H. pylori infection may induce carcinogenesis via epigenetic alterations in the promoter region of various genes. H. pylori is known to induce hypermethylation-silencing of several tumor suppressor genes in H. pylori-infected cancerous and H. pylori-infected non-cancerous gastric mucosae. This article presents a review of the published literature mainly from the last year 15 years. The topic focuses on H. pylori-induced DNA methylation linked to gastric cancer development. The authors have used MeSH terms “Helicobacter pylori” with “epigenetic,” “DNA methylation,” in combination with “gastric inflammation”, gastritis” and “gastric cancer” to search SCOPUS, PubMed, Ovid, and Web of Science databases. The success of epigenetic drugs such as de-methylating agents in the treatment of certain cancers has led towards new prospects that similar approaches could also be applied against gastric cancer. However, it is very important to understand the role of all the genes that have already been linked to H. pylori-induced DNA methylation in order to in order to evaluate the potential benefits of epigenetic drugs. Full article
(This article belongs to the Section Human Pathogens)
Open AccessArticle Genome Mining and Comparative Analysis of Streptococcus intermedius Causing Brain Abscess in a Child
Received: 12 December 2018 / Revised: 18 January 2019 / Accepted: 30 January 2019 / Published: 13 February 2019
Viewed by 119 | PDF Full-text (7148 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Streptococcus intermedius (SI) is associated with prolonged hospitalization and low survival rates. The genetic mechanisms involved in brain abscess development and genome evolution in comparison to other members of the Streptococcus anginosus group are understudied. We performed a whole-genome comparative analysis of an [...] Read more.
Streptococcus intermedius (SI) is associated with prolonged hospitalization and low survival rates. The genetic mechanisms involved in brain abscess development and genome evolution in comparison to other members of the Streptococcus anginosus group are understudied. We performed a whole-genome comparative analysis of an SI isolate, LAU_SINT, associated with brain abscess following sinusitis with all SI genomes in addition to S. constellatus and S. anginosus. Selective pressure on virulence factors, phages, pan-genome evolution and single-nucleotide polymorphism analysis were assessed. The structural details of the type seven secretion system (T7SS) was elucidated and compared with different organisms. ily and nanA were both abundant and conserved. Nisin resistance determinants were found in 47% of the isolates. Pan-genome and SNPs-based analysis didn’t reveal significant geo-patterns. Our results showed that two SC isolates were misidentified as SI. We propose the presence of four T7SS modules (I–IV) located on various genomic islands. We detected a variety of factors linked to metal ions binding on the GIs carrying T7SS. This is the first detailed report characterizing the T7SS and its link to nisin resistance and metal ions binding in SI. These and yet uncharacterized T7SS transmembrane proteins merit further studies and could represent potential therapeutic targets. Full article
(This article belongs to the Section Human Pathogens)
Figures

Figure 1

Open AccessArticle The Experimental Infections of the Human Isolate of Strongyloides Stercoralis in a Rodent Model (The Mongolian Gerbil, Meriones Unguiculatus)
Received: 9 January 2019 / Revised: 27 January 2019 / Accepted: 31 January 2019 / Published: 5 February 2019
Viewed by 181 | PDF Full-text (573 KB)
Abstract
Strongyloidiasis is life-threatening disease which is mainly caused by Strongyloides stercoralis infection. Autoinfection of the parasite results in long-lasting infection and fatal conditions, hyperinfection and dissemination (primarily in immunosuppressed hosts). However, mechanisms of autoinfection and biology remain largely unknown. Rodent models including mice [...] Read more.
Strongyloidiasis is life-threatening disease which is mainly caused by Strongyloides stercoralis infection. Autoinfection of the parasite results in long-lasting infection and fatal conditions, hyperinfection and dissemination (primarily in immunosuppressed hosts). However, mechanisms of autoinfection and biology remain largely unknown. Rodent models including mice and rats are not susceptible to the human isolate of S. stercoralis. Variations in susceptibility of the human isolate of S. stercoralis are found in dogs. S. ratti and S. venezuelensis infections in rats are an alternative model without the ability to cause autoinfection. The absence of appropriate model for the human isolate of strongyloidiasis hampers a better understanding of human strongyloidiasis. We demonstrated the maintenance of the human isolate of the S. stercoralis life cycle in the Mongolian gerbil (Meriones unguiculatus). The human isolate of S. stercoralis caused a patent infection in immunosuppressed gerbils, more than 18 months. The mean number of recovery adult parasitic worms were 120 ± 23 (1.2% of the initial dose) and L1s were 12,500 ± 7,500 after day 28 post-inoculation (p.i.). The prepatent period was 9–14 days. Mild diarrhoea was found in gerbils carrying a high number of adult parasitic worms. Our findings provided a promising model for studying biology and searching new alternative drugs against the parasites. Further studies about the hyperinfection and dissemination would be performed. Full article
(This article belongs to the Section Human Pathogens)
Open AccessArticle Antibacterial Activities of Herbal Toothpastes Combined with Essential Oils against Streptococcus mutans
Received: 17 December 2018 / Revised: 24 January 2019 / Accepted: 29 January 2019 / Published: 1 February 2019
Viewed by 222 | PDF Full-text (1762 KB) | HTML Full-text | XML Full-text
Abstract
In recent years, people have become more conscious about the side-effects of fluoride toothpastes and herbal products have drawn attention as alternatives in the struggle against caries. Studies have focused on the benefits of essential oils obtained from herbs because of their antibacterial [...] Read more.
In recent years, people have become more conscious about the side-effects of fluoride toothpastes and herbal products have drawn attention as alternatives in the struggle against caries. Studies have focused on the benefits of essential oils obtained from herbs because of their antibacterial effects. The aim of this study was to evaluate and compare the antibacterial activity of Origanum dubium and Cinnamomum cassia oils combined with herbal toothpastes against Streptococcus mutans. The antibacterial activity of the test materials was determined using the agar well diffusion method before and after the addition of essential oils. We tested the efficacy of Splat Organic and Splat Biocalcium against S. mutans (12 mm and 11 mm, respectively) doubled in combination with Origanum dubium (23 mm for both toothpastes) and tripled with Cinnamomum cassia (38 mm and 36 mm, respectively). Jack N’ Jill toothpaste, which did not initially show any antibacterial effect, exhibited the largest inhibition zones after the addition of the essential oils (38 mm for Origanum dubium and 39 mm for Cinnamomum cassia). The results of this study pointed out that herbal toothpastes exhibit statistically higher antibacterial activity against Streptococcus mutans (p < 0.05) than their initial forms after the addition of essential oils. Full article
(This article belongs to the Section Human Pathogens)
Figures

Figure 1

Open AccessReview Non-typhoidal Salmonella in the Pig Production Chain: A Comprehensive Analysis of Its Impact on Human Health
Received: 27 December 2018 / Revised: 21 January 2019 / Accepted: 24 January 2019 / Published: 29 January 2019
Viewed by 386 | PDF Full-text (970 KB) | HTML Full-text | XML Full-text
Abstract
Salmonellosis remains one of the most frequent foodborne zoonosis, constituting a worldwide major public health concern. The most frequent sources of human infections are food products of animal origin, being pork meat one of the most relevant. Currently, particular pig food production well-adapted [...] Read more.
Salmonellosis remains one of the most frequent foodborne zoonosis, constituting a worldwide major public health concern. The most frequent sources of human infections are food products of animal origin, being pork meat one of the most relevant. Currently, particular pig food production well-adapted and persistent Salmonella enterica serotypes (e.g., Salmonella Typhimurium, Salmonella 1,4,[5],12:i:-, Salmonella Derby and Salmonella Rissen) are frequently reported associated with human infections in diverse industrialized countries. The dissemination of those clinically-relevant Salmonella serotypes/clones has been related to the intensification of pig production chain and to an increase in the international trade of pigs and pork meat. Those changes that occurred over the years along the food chain may act as food chain drivers leading to new problems and challenges, compromising the successful control of Salmonella. Among those, the emergence of antibiotic resistance in non-typhoidal Salmonella associated with antimicrobials use in the pig production chain is of special concern for public health. The transmission of pig-related multidrug-resistant Salmonella serotypes, clones and/or genetic elements carrying clinically-relevant antibiotic resistance genes, frequently associated with metal tolerance genes, from pigs and pork meat to humans, has been reported and highlights the contribution of different drivers to the antibiotic resistance burden. Gathered data strengthen the need for global mandatory interventions and strategies for effective Salmonella control and surveillance across the pig production chain. The purpose of this review was to provide an overview of the role of pig and pork meat in human salmonellosis at a global scale, highlighting the main factors contributing to the persistence and dissemination of clinically-relevant pig-related Salmonella serotypes and clones. Full article
Figures

Figure 1

Open AccessArticle Potato Pathogens in Russia’s Regions: An Instrumental Survey with the Use of Real-Time PCR/RT-PCR in Matrix Format
Received: 27 November 2018 / Revised: 26 January 2019 / Accepted: 26 January 2019 / Published: 29 January 2019
Viewed by 188 | PDF Full-text (2323 KB) | HTML Full-text | XML Full-text
Abstract
Viral and bacterial diseases of potato cause significant yield loss worldwide. The current data on the occurrence of these diseases in Russia do not provide comprehensive understanding of the phytosanitary situation. Diagnostic systems based on disposable stationary open qPCR micromatrices intended for the [...] Read more.
Viral and bacterial diseases of potato cause significant yield loss worldwide. The current data on the occurrence of these diseases in Russia do not provide comprehensive understanding of the phytosanitary situation. Diagnostic systems based on disposable stationary open qPCR micromatrices intended for the detection of eight viral and seven bacterial/oomycetal potato diseases have been used for wide-scale screening of target pathogens to estimate their occurrence in 11 regions of Russia and to assess suitability of the technology for high-throughput diagnostics under conditions of field laboratories. Analysis of 1025 leaf and 725 tuber samples confirmed the earlier reported data on the dominance of potato viruses Y, S, and M in most regions of European Russia, as well as relatively high incidences of Clavibacter michiganensis subsp. sepedonicus, Pectobacterium atrosepticum, and P. carotovorum subsp. carotovorum, and provided detailed information on the phytosanitary status of selected regions and geographical spread of individual pathogens. Information on the occurrence of mixed infections, including their composition, was the first data set of this kind for Russia. The study is the first large-scale screening of a wide range of potato pathogens conducted in network mode using unified methodology and standardized qPCR micromatrices. The data represent valuable information for plant pathologists and potato producers and indicate the high potential of the combined use of matrix PCR technology and network approaches to data collection and analysis with the view to rapidly and accurately assess the prevalence of certain pathogens, as well as the phytosanitary state of large territories. Full article
(This article belongs to the Section Plant Pathogens)
Figures

Figure 1

Open AccessReview Virus–Host Interactions Involved in Lassa Virus Entry and Genome Replication
Received: 21 December 2018 / Revised: 25 January 2019 / Accepted: 26 January 2019 / Published: 29 January 2019
Viewed by 221 | PDF Full-text (1020 KB) | HTML Full-text | XML Full-text
Abstract
Lassa virus (LASV) is the causative agent of Lassa fever, a human hemorrhagic disease associated with high mortality and morbidity rates, particularly prevalent in West Africa. Over the past few years, a significant amount of novel information has been provided on cellular factors [...] Read more.
Lassa virus (LASV) is the causative agent of Lassa fever, a human hemorrhagic disease associated with high mortality and morbidity rates, particularly prevalent in West Africa. Over the past few years, a significant amount of novel information has been provided on cellular factors that are determinant elements playing a role in arenavirus multiplication. In this review, we focus on host proteins that intersect with the initial steps of the LASV replication cycle: virus entry and genome replication. A better understanding of relevant virus–host interactions essential for sustaining these critical steps may help to identify possible targets for the rational design of novel therapeutic approaches against LASV and other arenaviruses that cause severe human disease. Full article
Figures

Figure 1

Open AccessArticle In silico Identification of Novel Toxin Homologs and Associated Mobile Genetic Elements in Clostridium perfringens
Received: 18 December 2018 / Revised: 16 January 2019 / Accepted: 24 January 2019 / Published: 29 January 2019
Viewed by 428 | PDF Full-text (2198 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Clostridium perfringens causes a wide range of diseases in a variety of hosts, due to the production of a diverse set of toxins and extracellular enzymes. The C. perfringens toxins play an important role in pathogenesis, such that the presence and absence of [...] Read more.
Clostridium perfringens causes a wide range of diseases in a variety of hosts, due to the production of a diverse set of toxins and extracellular enzymes. The C. perfringens toxins play an important role in pathogenesis, such that the presence and absence of the toxins is used as a typing scheme for the species. In recent years, several new toxins have been discovered that have been shown to be essential or highly correlated to diseases; these include binary enterotoxin (BecAB), NetB and NetF. In the current study, genome sequence analysis of C. perfringens isolates from diverse sources revealed several putative novel toxin homologs, some of which appeared to be associated with potential mobile genetic elements, including transposons and plasmids. Four novel toxin homologs encoding proteins related to the pore-forming Leukocidin/Hemolysin family were found in type A and G isolates. Two novel toxin homologs encoding proteins related to the epsilon aerolysin-like toxin family were identified in Type A and F isolates from humans, contaminated food and turkeys. A novel set of proteins related to clostridial binary toxins was also identified. While phenotypic characterisation is required before any of these homologs can be established as functional toxins, the in silico identification of these novel homologs on mobile genetic elements suggests the potential toxin reservoir of C. perfringens may be much larger than previously thought. Full article
(This article belongs to the Section Animal Pathogens)
Figures

Figure 1

Open AccessArticle Antimicrobial Activity of Six Essential Oils Against a Group of Human Pathogens: A Comparative Study
Received: 6 January 2019 / Revised: 22 January 2019 / Accepted: 23 January 2019 / Published: 28 January 2019
Viewed by 399 | PDF Full-text (750 KB) | HTML Full-text | XML Full-text
Abstract
Essential oils are concentrated natural extracts derived from plants, which were proved to be good sources of bioactive compounds with antioxidative and antimicrobial properties. This study followed the effect of some commonly used essential oils in micellar and aqueous extract on some of [...] Read more.
Essential oils are concentrated natural extracts derived from plants, which were proved to be good sources of bioactive compounds with antioxidative and antimicrobial properties. This study followed the effect of some commonly used essential oils in micellar and aqueous extract on some of the most common pathogenic bacteria. Frankincense, myrtle, thyme, lemon, oregano and lavender essential oils were tested against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. Both micellar and aqueous extracts were used for determination of their minimal inhibitory (MIC) and bactericidal concentrations (MBC). The most active oils were oregano, thyme, lemon and lavender, while the least active were frankincense and myrtle. Oregano oil presented up to 64 times lower MICs/MBCs than ethylic alcohol, if considered as standard, on all bacteria. Most susceptible bacteria were the Gram-positive cocci, including methicillin resistant S. aureus, while the most resistant was P. aeruginosa. With some exceptions, the best activity was achieved by micelles suspension of essential oils, with MICs and MBCs ranging from 0.1% to > 50% v/v. Only oregano and lavender aqueous extracts presented bactericidal activity and only on K. pneumoniae (MIC = 6.3%). Thyme, lemon and oregano oils present significantly lower overall average MICs for their micellar form than for their aqueous extracts. The present results may suggest some formulas of colloid or micelle suspensions of whole essential oils such as oregano, thyme or lemon oil, that may help in antimicrobial fight. Aqueous extracts of oregano or thyme oil with good antibacterial activity could also be used in selected cases. Full article
Figures

Figure 1

Open AccessArticle Motility, Biofilm Formation and Antimicrobial Efflux of Sessile and Planktonic Cells of Achromobacter xylosoxidans
Received: 19 December 2018 / Revised: 18 January 2019 / Accepted: 24 January 2019 / Published: 27 January 2019
Viewed by 223 | PDF Full-text (1111 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Achromobacter xylosoxidans is an innately multidrug-resistant bacterium capable of forming biofilms in the respiratory tract of cystic fibrosis (CF) patients. During the transition from the planktonic stage to biofilm growth, bacteria undergo a transcriptionally regulated differentiation. An isolate of A. xylosoxidans cultured from [...] Read more.
Achromobacter xylosoxidans is an innately multidrug-resistant bacterium capable of forming biofilms in the respiratory tract of cystic fibrosis (CF) patients. During the transition from the planktonic stage to biofilm growth, bacteria undergo a transcriptionally regulated differentiation. An isolate of A. xylosoxidans cultured from the sputum of a CF patient was separated into sessile and planktonic stages in vitro, and the transcriptomes were compared. The selected genes of interest were subsequently inactivated, and flagellar motility was found to be decisive for biofilm formation in vitro. The spectrum of a new resistance-nodulation-cell division (RND)-type multidrug efflux pump (AxyEF-OprN) was characterized by inactivation of the membrane fusion protein. AxyEF-OprN is capable of extruding some fluoroquinolones (levofloxacin and ciprofloxacin), tetracyclines (doxycycline and tigecycline) and carpabenems (ertapenem and imipenem), which are classes of antimicrobials that are widely used for treatment of CF pulmonary infections. Full article
(This article belongs to the Section Human Pathogens)
Figures

Figure 1

Open AccessCase Report Disease Manifestation and Viral Sequences in a Bonobo More Than 30 Years after Papillomavirus Infection
Received: 20 October 2018 / Revised: 27 December 2018 / Accepted: 15 January 2019 / Published: 26 January 2019
Viewed by 200 | PDF Full-text (1196 KB) | HTML Full-text | XML Full-text
Abstract
Pan paniscus Papillomavirus 1 (PpPV1) causes focal epithelial hyperplasia (FEH) in infected animals. Here, we analyzed the present disease manifestation and PpPV1 genomic sequence of an animal that was afflicted by an FEH epizootic outbreak in 1987 for which the sequence of the [...] Read more.
Pan paniscus Papillomavirus 1 (PpPV1) causes focal epithelial hyperplasia (FEH) in infected animals. Here, we analyzed the present disease manifestation and PpPV1 genomic sequence of an animal that was afflicted by an FEH epizootic outbreak in 1987 for which the sequence of the responsible PpPV1 was determined. The animal displayed FEH more than 30 years after the initial diagnosis, indicating persistence or recurrence of the disease, and evidence for active PpPV1 infection was obtained. Moreover, the sequences of the viral genomes present in the late 1980s and in 2018 differed at 23 nucleotide positions, resulting in 11 amino acid exchanges within coding regions. These findings suggest that PpPV1-induced FEH might not undergo complete and/or permanent remission in a subset of afflicted animals. Full article
Figures

Figure 1

Open AccessArticle In Vitro Comparison of Antibacterial and Antibiofilm Activities of Selected Fluoroquinolones against Pseudomonas aeruginosa and Methicillin-Resistant Staphylococcus aureus
Received: 7 December 2018 / Revised: 18 January 2019 / Accepted: 21 January 2019 / Published: 24 January 2019
Viewed by 245 | PDF Full-text (238 KB) | HTML Full-text | XML Full-text
Abstract
An in vitro overview of the inhibitory effects of selected fluoroquinolones against planktonic and biofilm cells of the methicillin-resistant Staphylococcus aureus (MRSA) strain American type culture collection (ATCC) 43300 and the Pseudomonas aeruginosa strain ATCC 27853 was carried out. Biofilm cells of both [...] Read more.
An in vitro overview of the inhibitory effects of selected fluoroquinolones against planktonic and biofilm cells of the methicillin-resistant Staphylococcus aureus (MRSA) strain American type culture collection (ATCC) 43300 and the Pseudomonas aeruginosa strain ATCC 27853 was carried out. Biofilm cells of both strains were less susceptible to the selected antibiotics than their planktonic counterparts. In addition, certain antibiotics were more effective against biofilm cells, while others performed better on the planktonic cells. Against P. aeruginosa, ciprofloxacin was the most potent on both planktonic and biofilm cells, whereas ofloxacin was the least potent on both biofilm and planktonic cells. Moxifloxacin and gatifloxacin were the most potent against both planktonic and biofilm MRSA bacteria, however, not in the same order of activity. Norfloxacin was the least active when tested against both planktonic and biofilm cells. The results of this work are expected to provide insight into the efficacy of various fluoroquinolones against MRSA and Pseudomonas aeruginosa biofilms. This study could form the basis for future clinical studies that could recommend special guidelines for the management of infections that are likely to involve bacteria in their biofilm state. Full article
(This article belongs to the Section Human Pathogens)
Open AccessEditorial Malaria Resurgence in the Americas: An Underestimated Threat
Received: 12 January 2019 / Accepted: 14 January 2019 / Published: 18 January 2019
Viewed by 571 | PDF Full-text (463 KB) | HTML Full-text | XML Full-text
Abstract
Malaria is a mosquito-borne disease caused by parasites of the genus Plasmodium (P [...] Full article
Figures

Figure 1

Open AccessArticle Emergence and Spread of Extended Spectrum β-Lactamase Producing Enterobacteriaceae (ESBL-PE) in Pigs and Exposed Workers: A Multicentre Comparative Study between Cameroon and South Africa
Received: 18 December 2018 / Revised: 10 January 2019 / Accepted: 11 January 2019 / Published: 16 January 2019
Viewed by 320 | PDF Full-text (913 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Extended spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) represent a significant public health concern globally and are recognized by the World Health Organization as pathogens of critical priority. However, the prevalence of ESBL-PE in food animals and humans across the farm-to-plate continuum is yet to be [...] Read more.
Extended spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) represent a significant public health concern globally and are recognized by the World Health Organization as pathogens of critical priority. However, the prevalence of ESBL-PE in food animals and humans across the farm-to-plate continuum is yet to be elucidated in Sub-Saharan countries including Cameroon and South Africa. This work sought to determine the risk factors, carriage, antimicrobial resistance profiles and genetic relatedness of extended spectrum β-lactamase producing Enterobacteriaceae (ESBL-PE) amid pigs and abattoir workers in Cameroon and South Africa. ESBL-PE from pooled samples of 432 pigs and nasal and hand swabs of 82 humans were confirmed with VITEK 2 system. Genomic fingerprinting was performed by ERIC-PCR. Logistic regression (univariate and multivariate) analyses were carried out to identify risk factors for human ESBL-PE carriage using a questionnaire survey amongst abattoir workers. ESBL-PE prevalence in animal samples from Cameroon were higher than for South Africa and ESBL-PE carriage was observed in Cameroonian workers only. Nasal ESBL-PE colonization was statistically significantly associated with hand ESBL-PE (21.95% vs. 91.67%; p = 0.000; OR = 39.11; 95% CI 2.02–755.72; p = 0.015). Low level of education, lesser monthly income, previous hospitalization, recent antibiotic use, inadequate handwashing, lack of training and contact with poultry were the risk factors identified. The study highlights the threat posed by ESBL-PE in the food chain and recommends the implementation of effective strategies for antibiotic resistance containment in both countries. Full article
(This article belongs to the Special Issue Zoonotic Diseases and One Health)
Figures

Figure 1

Open AccessArticle Attenuated Replication of Lassa Virus Vaccine Candidate ML29 in STAT-1-/- Mice
Received: 6 December 2018 / Revised: 28 December 2018 / Accepted: 11 January 2019 / Published: 15 January 2019
Viewed by 272 | PDF Full-text (8731 KB) | HTML Full-text | XML Full-text
Abstract
Lassa virus (LASV), a highly prevalent mammalian arenavirus endemic in West Africa, can cause Lassa fever (LF), which is responsible for thousands of deaths annually. LASV is transmitted to humans from naturally infected rodents. At present, there is not an effective vaccine nor [...] Read more.
Lassa virus (LASV), a highly prevalent mammalian arenavirus endemic in West Africa, can cause Lassa fever (LF), which is responsible for thousands of deaths annually. LASV is transmitted to humans from naturally infected rodents. At present, there is not an effective vaccine nor treatment. The genetic diversity of LASV is the greatest challenge for vaccine development. The reassortant ML29 carrying the L segment from the nonpathogenic Mopeia virus (MOPV) and the S segment from LASV is a vaccine candidate under current development. ML29 demonstrated complete protection in validated animal models against a Nigerian strain from clade II, which was responsible for the worst outbreak on record in 2018. This study demonstrated that ML29 was more attenuated than MOPV in STAT1-/- mice, a small animal model of human LF and its sequelae. ML29 infection of these mice resulted in more than a thousand-fold reduction in viremia and viral load in tissues and strong LASV-specific adaptive T cell responses compared to MOPV-infected mice. Persistent infection of Vero cells with ML29 resulted in generation of interfering particles (IPs), which strongly interfered with the replication of LASV, MOPV and LCMV, the prototype of the Arenaviridae. ML29 IPs induced potent cell-mediated immunity and were fully attenuated in STAT1-/- mice. Formulation of ML29 with IPs will improve the breadth of the host’s immune responses and further contribute to development of a pan-LASV vaccine with full coverage meeting the WHO requirements. Full article
Figures

Figure 1

Open AccessArticle Microbiological Air Quality in Heating, Ventilation and Air Conditioning Systems of Surgical and Intensive Care Areas: The Application of a Disinfection Procedure for Dehumidification Devices
Received: 3 December 2018 / Revised: 7 January 2019 / Accepted: 11 January 2019 / Published: 15 January 2019
Viewed by 221 | PDF Full-text (1625 KB) | HTML Full-text | XML Full-text
Abstract
International literature data report that the increase of infectious risk may be due to heating, ventilation and air conditioning (HVAC) systems contaminated by airborne pathogens. Moreover, the presence of complex rotating dehumidification wheels (RDWs) may complicate the cleaning and disinfection procedures of the [...] Read more.
International literature data report that the increase of infectious risk may be due to heating, ventilation and air conditioning (HVAC) systems contaminated by airborne pathogens. Moreover, the presence of complex rotating dehumidification wheels (RDWs) may complicate the cleaning and disinfection procedures of the HVAC systems. We evaluated the efficacy of a disinfection strategy applied to the RDW of two hospitals’ HVAC systems. Hospitals have four RDW systems related to the surgical areas (SA1 and SA2) and to the intensive and sub-intensive care (IC and sIC) units. Microbiological air and surface analyses were performed in HVAC systems, before and after the disinfection treatment. Hydrogen peroxide (12%) with silver ions (10 mg/L) was aerosolized in all the air sampling points, located close to the RDW device. After the air disinfection procedure, reductions of total microbial counts at 22 °C and molds were achieved in SA2 and IC HVAC systems. An Aspergillus fumigatus contamination (6 CFU/500 L), detected in one air sample collected in the IC HVAC system, was eradicated after the disinfection. The surface samples proved to be of good microbiological quality. The results suggest the need for a disinfection procedure to improve the microbiological quality of the complex HVAC systems, mostly in surgical and intensive care areas. Full article
(This article belongs to the Section Waterborne/Foodborne/Airborne Pathogens)
Figures

Figure 1

Open AccessArticle Molecular Characterisation of Equine Herpesvirus 1 Isolates from Cases of Abortion, Respiratory and Neurological Disease in Ireland between 1990 and 2017
Received: 17 December 2018 / Revised: 4 January 2019 / Accepted: 8 January 2019 / Published: 15 January 2019
Viewed by 250 | PDF Full-text (4563 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Multiple locus typing based on sequencing heterologous regions in 26 open reading frames (ORFs) of equine herpesvirus 1 (EHV-1) strains Ab4 and V592 was used to characterise 272 EHV-1 isolates from 238 outbreaks of abortion, respiratory or neurological disease over a 28-year period. [...] Read more.
Multiple locus typing based on sequencing heterologous regions in 26 open reading frames (ORFs) of equine herpesvirus 1 (EHV-1) strains Ab4 and V592 was used to characterise 272 EHV-1 isolates from 238 outbreaks of abortion, respiratory or neurological disease over a 28-year period. The analysis grouped the 272 viruses into at least 10 of the 13 unique long region (UL) clades previously recognised. Viruses from the same outbreak had identical multi-locus profiles. Sequencing of the ORF68 region of EHV-1 isolates from 222 outbreaks established a divergence into seven groups and network analysis demonstrated that Irish genotypes were not geographically restricted but clustered with viruses from all over the world. Multi-locus analysis proved a more comprehensive method of strain typing than ORF68 sequencing. It was demonstrated that when interpreted in combination with epidemiological data, this type of analysis has a potential role in tracking virus between premises and therefore in the implementation of targeted control measures. Viruses from 31 of 238 outbreaks analysed had the proposed ORF30 G2254/D752 neuropathogenic marker. There was a statistically significant association between viruses of the G2254/D752 genotype and both neurological disease and hypervirulence as defined by outbreaks involving multiple abortion or neurological cases. The association of neurological disease in those with the G2254/D752 genotype was estimated as 27 times greater than in those with the A2254/N752 genotype. Full article
(This article belongs to the Section Animal Pathogens)
Figures

Figure 1

Open AccessArticle The Effect of Bacillus licheniformis MH48 on Control of Foliar Fungal Diseases and Growth Promotion of Camellia oleifera Seedlings in the Coastal Reclaimed Land of Korea
Received: 14 November 2018 / Revised: 3 January 2019 / Accepted: 4 January 2019 / Published: 9 January 2019
Viewed by 345 | PDF Full-text (4454 KB) | HTML Full-text | XML Full-text
Abstract
This study investigated the control of foliar fungal diseases and growth promotion of Camellia oleifera seedlings in coastal reclaimed land through the use of Bacillus licheniformis MH48. B. licheniformis MH48 can produce lytic enzymes chitinase and β-1,3-glucanase that can inhibit foliar pathogens by [...] Read more.
This study investigated the control of foliar fungal diseases and growth promotion of Camellia oleifera seedlings in coastal reclaimed land through the use of Bacillus licheniformis MH48. B. licheniformis MH48 can produce lytic enzymes chitinase and β-1,3-glucanase that can inhibit foliar pathogens by 37.4 to 50.5%. Nevertheless, foliar diseases appeared in the seedlings with bacterial inoculation, and their survival rate decreased because they were unable to withstand salt stress. However, B. licheniformis MH48 significantly increased the total nitrogen and phosphorus contents in the soils through fixing atmospheric nitrogen and solubilizing phosphorus. The growth of seedlings with bacterial inoculation increased, particularly in root dry weight, by 7.42 g plant−1, which was 1.7-fold greater than that of the control. B. licheniformis MH48 produces the phytohormone auxin, which potentially stimulates seedling root growth. C. oleifera seedlings significantly increased in total nitrogen content to 317.57 mg plant−1 and total phosphorus content to 46.86 mg plant−1. Our results revealed the effectiveness of B. licheniformis MH48 not only in the control of foliar fungal diseases but also in the growth promotion of C. oleifera seedlings in coastal lands. Full article
(This article belongs to the Special Issue Fungal Pathogens of Forest Trees)
Figures

Figure 1

Open AccessEditorial Acknowledgement to Reviewers of Pathogens in 2018
Published: 8 January 2019
Viewed by 265 | PDF Full-text (203 KB) | HTML Full-text | XML Full-text
Abstract
Rigorous peer-review is the corner-stone of high-quality academic publishing [...] Full article
Open AccessCommunication Diversity of Bacterial Biota in Capnodis tenebrionis (Coleoptera: Buprestidae) Larvae
Received: 2 December 2018 / Revised: 1 January 2019 / Accepted: 4 January 2019 / Published: 6 January 2019
Viewed by 426 | PDF Full-text (1466 KB) | HTML Full-text | XML Full-text
Abstract
The bacterial biota in larvae of Capnodis tenebrionis, a serious pest of cultivated stone-fruit trees in the West Palearctic, was revealed for the first time using the MiSeq platform. The core bacterial community remained the same in neonates whether upon hatching or [...] Read more.
The bacterial biota in larvae of Capnodis tenebrionis, a serious pest of cultivated stone-fruit trees in the West Palearctic, was revealed for the first time using the MiSeq platform. The core bacterial community remained the same in neonates whether upon hatching or grown on peach plants or an artificial diet, suggesting that C. tenebrionis larvae acquire much of their bacterial biome from the parent adult. Reads affiliated with class levels Gammaproteobacteria and Alphaproteobacteria (phylum Proteobacteria ca. 86%), and Actinobacteria (ca. 14%) were highly abundant. Most diverse reads belong to the families Xanthomonadaceae (50%), Methylobacteriaceae (20%), Hyphomicrobiaceae (9%), Micrococcaceae (7%) and Geodermatophilaceae (4.5%). About two-thirds of the reads are affiliated with the genera Lysobacter, Microvirga, Methylobacterium, and Arthrobacter, which encompass species displaying cellulolytic and lipolytic activities. This study provides a foundation for future studies to elucidate the roles of bacterial biota in C. tenebrionis. Full article
(This article belongs to the Section Plant Pathogens)
Figures

Figure 1

Open AccessArticle Serological Survey of Ehrlichia canis and Anaplasma phagocytophilum in Dogs from Central Italy: An Update (2013–2017)
Received: 19 November 2018 / Revised: 21 December 2018 / Accepted: 31 December 2018 / Published: 4 January 2019
Viewed by 316 | PDF Full-text (226 KB) | HTML Full-text | XML Full-text
Abstract
Ehrlichia canis and Anaplasma phagocytophilum are tick-borne bacteria of veterinary concern. Indirect immunofluorescent assay was carried out to detect antibodies against E. canis and A. phagocytophilum in 1026 owned dogs living in Central Italy during the period 2013–2017. One hundred and eighty-six (18.12%) [...] Read more.
Ehrlichia canis and Anaplasma phagocytophilum are tick-borne bacteria of veterinary concern. Indirect immunofluorescent assay was carried out to detect antibodies against E. canis and A. phagocytophilum in 1026 owned dogs living in Central Italy during the period 2013–2017. One hundred and eighty-six (18.12%) dogs were positive for at least one pathogen and 14 (1.36%) for both agents. More in detail, 166 (16.18%) samples were positive for E. canis and 34 (3.31%) for A. phagocytophilum. No statistically significant differences in the seroprevalence values related to gender were detected, whereas the highest rate to E. canis occurred in animals aged more than 10 years. Mean seroprevalence values for both E. canis and A. phagocytophilum detected in 2014 and 2015 were statistically higher with respect to other years. Even though dogs’ owners are informed about the risk of pet infections by tick-borne pathogens and prophylaxis against ticks is often executed, E. canis and A. phagocytophilum are still present and infect the canine population in Central Italy. Full article
(This article belongs to the Special Issue Ticks and Tick Borne Diseases Surveillance)
Open AccessArticle Staphylococcus aureus Superantigen-Like Protein SSL1: A Toxic Protease
Received: 7 November 2018 / Revised: 12 December 2018 / Accepted: 20 December 2018 / Published: 1 January 2019
Viewed by 608 | PDF Full-text (6695 KB) | HTML Full-text | XML Full-text
Abstract
Staphylococcus aureus is a major cause of corneal infections that can cause reduced vision, even blindness. Secreted toxins cause tissue damage and inflammation resulting in scars that lead to vision loss. Identifying tissue damaging proteins is a prerequisite to limiting these harmful reactions. [...] Read more.
Staphylococcus aureus is a major cause of corneal infections that can cause reduced vision, even blindness. Secreted toxins cause tissue damage and inflammation resulting in scars that lead to vision loss. Identifying tissue damaging proteins is a prerequisite to limiting these harmful reactions. The present study characterized a previously unrecognized S. aureus toxin. This secreted toxin was purified from strain Newman ΔhlaΔhlg, the N-terminal sequence determined, the gene cloned, and the purified recombinant protein was tested in the rabbit cornea. The virulence of a toxin deletion mutant was compared to its parent and the mutant after gene restoration (rescue strain). The toxin (23 kDa) had an N-terminal sequence matching the Newman superantigen-like protein SSL1. An SSL1 homodimer (46 kDa) had proteolytic activity as demonstrated by zymography and cleavage of a synthetic substrate, collagens, and cytokines (IL-17A, IFN-γ, and IL-8); the protease was susceptible to serine protease inhibitors. As compared to the parent and rescue strains, the ssl1 mutant had significantly reduced virulence, but not reduced bacterial growth, in vivo. The ocular isolates tested had the ssl1 gene, with allele type 2 being the predominant type. SSL1 is a protease with corneal virulence and activity on host defense and structural proteins. Full article
(This article belongs to the Section Human Pathogens)
Figures

Figure 1

Open AccessArticle Identification of Residues in Lassa Virus Glycoprotein Subunit 2 That Are Critical for Protein Function
Received: 28 November 2018 / Revised: 20 December 2018 / Accepted: 22 December 2018 / Published: 26 December 2018
Viewed by 594 | PDF Full-text (2152 KB) | HTML Full-text | XML Full-text
Abstract
Lassa virus (LASV) is an Old World arenavirus, endemic to West Africa, capable of causing hemorrhagic fever. Currently, there are no approved vaccines or effective antivirals for LASV. However, thorough understanding of the LASV glycoprotein and entry into host cells could accelerate therapeutic [...] Read more.
Lassa virus (LASV) is an Old World arenavirus, endemic to West Africa, capable of causing hemorrhagic fever. Currently, there are no approved vaccines or effective antivirals for LASV. However, thorough understanding of the LASV glycoprotein and entry into host cells could accelerate therapeutic design. LASV entry is a two-step process involving the viral glycoprotein (GP). First, the GP subunit 1 (GP1) binds to the cell surface receptor and the viral particle is engulfed into an endosome. Next, the drop in pH triggers GP rearrangements, which ultimately leads to the GP subunit 2 (GP2) forming a six-helix-bundle (6HB). The process of GP2 forming 6HB fuses the lysosomal membrane with the LASV envelope, allowing the LASV genome to enter the host cell. The aim of this study was to identify residues in GP2 that are crucial for LASV entry. To achieve this, we performed alanine scanning mutagenesis on GP2 residues. We tested these mutant GPs for efficient GP1-GP2 cleavage, cell-to-cell membrane fusion, and transduction into cells expressing α-dystroglycan and secondary LASV receptors. In total, we identified seven GP2 mutants that were cleaved efficiently but were unable to effectively transduce cells: GP-L280A, GP-L285A/I286A, GP-I323A, GP-L394A, GP-I403A, GP-L415A, and GP-R422A. Therefore, the data suggest these residues are critical for GP2 function in LASV entry. Full article
Figures

Figure 1

Pathogens EISSN 2076-0817 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top