Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (32)

Search Parameters:
Keywords = Ornithodoros

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
20 pages, 2180 KiB  
Article
Insights into the Regulatory Roles of miRNAs in the Salivary Glands of the Soft Ticks Ornithodoros moubata and Ornithodoros erraticus
by Ana Laura Cano-Argüelles, Ricardo Pérez-Sánchez, Cristian Gallardo-Escárate, Rocío Vizcaíno-Marín, María González-Sánchez and Ana Oleaga
Pathogens 2025, 14(6), 595; https://doi.org/10.3390/pathogens14060595 - 17 Jun 2025
Viewed by 413
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression by inhibiting or degrading messenger RNAs (mRNAs). In ticks, salivary miRNAs are proposed to play key roles in modulating host–vector interactions during blood feeding. Previously, we identified salivary miRNAs in Ornithodoros moubata and [...] Read more.
MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression by inhibiting or degrading messenger RNAs (mRNAs). In ticks, salivary miRNAs are proposed to play key roles in modulating host–vector interactions during blood feeding. Previously, we identified salivary miRNAs in Ornithodoros moubata and Ornithodoros erraticus, major vectors of African swine fever and tick-borne human relapsing fever. In this study, we investigated the regulatory roles of salivary miRNAs in tick biology. Salivary miRNA datasets were re-analysed to identify conserved miRNAs, and putative target genes were predicted using the sialotranscriptomes of both species. In silico predictions were validated through experimental inhibition of specific miRNAs using antagomirs. Knockdown of miR-375 and miR-1 significantly reduced blood intake, oviposition, and fertility, indicating their involvement in feeding and reproductive processes. Silencing miR-252b in O. moubata led to increased mortality, suggesting a critical role in survival. Notably, Metis1 was identified as a likely target of miR-252b, and its dysregulation may underlie the observed lethality in miR-252b-silenced ticks. These findings highlight the functional relevance of salivary miRNAs in tick physiology and host interaction, offering new perspectives for the development of innovative tick control strategies. Full article
(This article belongs to the Section Ticks)
Show Figures

Graphical abstract

15 pages, 969 KiB  
Article
Vector-Borne Bacteria Detected in Ticks, Mites and Flies Parasitizing Bats in the State of Rondônia, Brazilian Amazon
by Leormando Fortunato Dornelas Júnior, Irineu Norberto Cunha, Felipe Rodrigues Jorge, Gustavo Graciolli, Ricardo Bassini-Silva, Fernando de Castro Jacinavicius, Maria Carolina A. Serpa, Marcelo Bahia Labruna, Felipe Arley Costa Pessoa and Luís Marcelo Aranha Camargo
Pathogens 2025, 14(4), 338; https://doi.org/10.3390/pathogens14040338 - 31 Mar 2025
Viewed by 749
Abstract
Bats (Chiroptera) are among the most diverse and geographically dispersed mammals. They are of great importance to the ecosystem, as pollinators, seed dispersers and pest controllers, in addition to being hosts to several parasitic arthropods, including ticks, mites, lice, fleas and flies. Their [...] Read more.
Bats (Chiroptera) are among the most diverse and geographically dispersed mammals. They are of great importance to the ecosystem, as pollinators, seed dispersers and pest controllers, in addition to being hosts to several parasitic arthropods, including ticks, mites, lice, fleas and flies. Their diet includes the tissue and blood or other body fluids of bats. Bats are reservoirs of several disease-causing agents, many of them pathogenic to humans, such as bacteria, as well as protozoa, viruses and fungi. This study was conducted in Monte Negro, Rondônia, Brazil and the occurrence of parasitic arthropods in bats was evaluated, as well as a screening of bacteria that these ectoparasites can carry. Through a total of 69 nocturnal captures, 217 chiropterans were sampled, representing 23 species and six families. A total of 592 specimens of parasitic arthropods (ticks, mites and flies) were collected from these bats (9% dipterans, 59% ticks and 32% mites). Bartonella spp. were found in two species of bat flies (Trichobius joblingi and Strebla mirabilis) in peri-urban and forest areas with an infection rate of 62% and 38%, respectively. We report for the first time in Rondônia the argasid tick Ornithodoros hasei and its infection by a spotted fever group bacterium ‘Candidatus Rickettsia wissemanii’ in a peri-urban area. Full article
(This article belongs to the Special Issue Zoonotic Pathogens in the Tropics: From the Forest to the Cities)
Show Figures

Figure 1

17 pages, 2470 KiB  
Article
Complete Genome Sequencing and Comparative Phylogenomics of Nine African Swine Fever Virus (ASFV) Isolates of the Virulent East African p72 Genotype IX without Viral Sequence Enrichment
by Jean-Baka Domelevo Entfellner, Edward Abworo Okoth, Cynthia Kavulani Onzere, Chris Upton, Emma Peter Njau, Dirk Höper, Sonal P. Henson, Samuel O. Oyola, Edwina Bochere, Eunice M. Machuka and Richard P. Bishop
Viruses 2024, 16(9), 1466; https://doi.org/10.3390/v16091466 - 14 Sep 2024
Cited by 1 | Viewed by 1506
Abstract
African swine fever virus (ASFV) is endemic to African wild pigs (Phacochoerus and Potamochoerus), in which viral infection is asymptomatic, and Ornithodoros soft ticks. However, ASFV causes a lethal disease in Eurasian domestic pigs (Sus scrofa). While Sub-Saharan Africa [...] Read more.
African swine fever virus (ASFV) is endemic to African wild pigs (Phacochoerus and Potamochoerus), in which viral infection is asymptomatic, and Ornithodoros soft ticks. However, ASFV causes a lethal disease in Eurasian domestic pigs (Sus scrofa). While Sub-Saharan Africa is believed to be the original home of ASFV, publicly available whole-genome ASFV sequences show a strong bias towards p72 Genotypes I and II, which are responsible for domestic pig pandemics outside Africa. To reduce this bias, we hereby describe nine novel East African complete genomes in p72 Genotype IX and present the phylogenetic analysis of all 16 available Genotype IX genomes compared with other ASFV p72 clades. We also document genome-level differences between one specific novel Genotype IX genome sequence (KE/2013/Busia.3) and a wild boar cell-passaged derivative. The Genotype IX genomes clustered with the five available Genotype X genomes. By contrast, Genotype IX and X genomes were strongly phylogenetically differentiated from all other ASFV genomes. The p72 gene region, on which the p72-based virus detection primers are derived, contains consistent SNPs in Genotype IX, potentially resulting in reduced sensitivity of detection. In addition to the abovementioned cell-adapted variant, eight novel ASFV Genotype IX genomes were determined: five from viruses passaged once in primary porcine peripheral blood monocytes and three generated from DNA isolated directly from field-sampled kidney tissues. Based on this methodological simplification, genome sequencing of ASFV field isolates should become increasingly routine and result in a rapid expansion of knowledge pertaining to the diversity of African ASFV at the whole-genome level. Full article
(This article belongs to the Special Issue African Swine Fever Virus 4.0)
Show Figures

Figure 1

20 pages, 3270 KiB  
Article
Chemical Synthesis and Structure–Activity Relationship Studies of the Coagulation Factor Xa Inhibitor Tick Anticoagulant Peptide from the Hematophagous Parasite Ornithodoros moubata
by Vincenzo De Filippis, Laura Acquasaliente, Andrea Pierangelini and Oriano Marin
Biomimetics 2024, 9(8), 485; https://doi.org/10.3390/biomimetics9080485 - 12 Aug 2024
Viewed by 1770
Abstract
Tick Anticoagulant Peptide (TAP), a 60-amino acid protein from the soft tick Ornithodoros moubata, inhibits activated coagulation factor X (fXa) with almost absolute specificity. Despite TAP and Bovine Pancreatic Trypsin Inhibitor (BPTI) (i.e., the prototype of the Kunitz-type protease inhibitors) sharing a [...] Read more.
Tick Anticoagulant Peptide (TAP), a 60-amino acid protein from the soft tick Ornithodoros moubata, inhibits activated coagulation factor X (fXa) with almost absolute specificity. Despite TAP and Bovine Pancreatic Trypsin Inhibitor (BPTI) (i.e., the prototype of the Kunitz-type protease inhibitors) sharing a similar 3D fold and disulphide bond topology, they have remarkably different amino acid sequence (only ~24% sequence identity), thermal stability, folding pathways, protease specificity, and even mechanism of protease inhibition. Here, fully active and correctly folded TAP was produced in reasonably high yields (~20%) by solid-phase peptide chemical synthesis and thoroughly characterised with respect to its chemical identity, disulphide pairing, folding kinetics, conformational dynamics, and fXa inhibition. The versatility of the chemical synthesis was exploited to perform structure–activity relationship studies on TAP by incorporating non-coded amino acids at positions 1 and 3 of the inhibitor. Using Hydrogen–Deuterium Exchange Mass Spectrometry, we found that TAP has a remarkably higher conformational flexibility compared to BPTI, and propose that these different dynamics could impact the different folding pathway and inhibition mechanisms of TAP and BPTI. Hence, the TAP/BPTI pair represents a nice example of divergent evolution, while the relative facility of TAP synthesis could represent a good starting point to design novel synthetic analogues with improved pharmacological profiles. Full article
(This article belongs to the Special Issue Biomimetic Approaches in Healthcare—Innovations Inspired by Nature)
Show Figures

Figure 1

13 pages, 1776 KiB  
Article
Molecular Analysis of Tick-Borne Bacterial Pathogens from Ticks Infesting Animal Hosts in Kyrgyzstan, 2021
by Yu Jung Kim, Ji Ye Seo, Jin Seo Park, Seong Yoon Kim, Bekbolsun Aknazarov, Nurzina Atabekova and Hee Il Lee
Microorganisms 2024, 12(6), 1046; https://doi.org/10.3390/microorganisms12061046 - 22 May 2024
Cited by 5 | Viewed by 1768
Abstract
This study investigated the prevalence of Anaplasma and Ehrlichia in 494 engorged ticks collected from various animal hosts, including cattle, horses, sheep, chickens, dogs, and cats, in six regions of northern Kyrgyzstan. Ten tick species, belonging to two families and six genera, were [...] Read more.
This study investigated the prevalence of Anaplasma and Ehrlichia in 494 engorged ticks collected from various animal hosts, including cattle, horses, sheep, chickens, dogs, and cats, in six regions of northern Kyrgyzstan. Ten tick species, belonging to two families and six genera, were identified based on CO1, 16S rRNA, and ITS2 genes: Argas persicus (26.5%), Haemaphysalis punctata (18.0%), Dermacentor spp. (16.0%), Rhipicephalus annulatus (11.8%), R. turanicus (10.9%), D. marginatus (7.7%), Hyalomma scupense (4.5%), Hy. marginatum (3.8%), R. sangineus complex (0.6%), and Ornithodoros lahorensis (0.2%). PCR analysis revealed a 15.0% (74/494) overall infection rate of Anaplasma and Ehrlichia. Anaplasma species were found in six tick species and were identified as A. bovis (n = 44), Anaplasma spp. (n = 20), A. ovis (n = 5), and A. capra (n = 2). Ehrlichia species were found only in H. punctata (n = 5) and identified as E. chaffeensis (n = 1) and Ehrlichia spp. (n = 4). Additionally, two H. punctata were co-infected with Anaplasma and Ehrlichia. This is the first study to investigate tick-borne bacterial pathogens in ticks collected from animal hosts in Kyrgyzstan. Our findings contribute to a better understanding of the epidemiology and emergence of tick-borne infections in Kyrgyzstan. Full article
(This article belongs to the Section Parasitology)
Show Figures

Figure 1

18 pages, 2264 KiB  
Review
Rabbits as Animal Models for Anti-Tick Vaccine Development: A Global Scenario
by Arlex Rodríguez-Durán, Shafi Ullah, Luís Fernando Parizi, Abid Ali and Itabajara da Silva Vaz Junior
Pathogens 2023, 12(9), 1117; https://doi.org/10.3390/pathogens12091117 - 1 Sep 2023
Cited by 7 | Viewed by 3181
Abstract
Studies evaluating candidate tick-derived proteins as anti-tick vaccines in natural hosts have been limited due to high costs. To overcome this problem, animal models are used in immunization tests. The aim of this article was to review the use of rabbits as an [...] Read more.
Studies evaluating candidate tick-derived proteins as anti-tick vaccines in natural hosts have been limited due to high costs. To overcome this problem, animal models are used in immunization tests. The aim of this article was to review the use of rabbits as an experimental model for the evaluation of tick-derived proteins as vaccines. A total of 57 tick proteins were tested for their immunogenic potential using rabbits as models for vaccination. The most commonly used rabbit breeds were New Zealand (73.8%), Japanese white (19%), Californians (4.8%) and Flemish lop-eared (2.4%) rabbits. Anti-tick vaccines efficacy resulted in up to 99.9%. Haemaphysalis longicornis (17.9%) and Ornithodoros moubata (12.8%) were the most common tick models in vaccination trials. Experiments with rabbits have revealed that some proteins (CoAQP, OeAQP, OeAQP1, Bm86, GST-Hl, 64TRP, serpins and voraxin) can induce immune responses against various tick species. In addition, in some cases it was possible to determine that the vaccine efficacy in rabbits was similar to that of experiments performed on natural hosts (e.g., Bm86, IrFER2, RmFER2, serpins and serine protease inhibitor). In conclusion, results showed that prior to performing anti-tick vaccination trials using natural hosts, rabbits can be used as suitable experimental models for these studies. Full article
(This article belongs to the Collection Advances in Tick Research)
Show Figures

Graphical abstract

17 pages, 1416 KiB  
Article
Ornithodoros sonrai Soft Ticks and Associated Bacteria in Senegal
by El Hadji Ibrahima Ndiaye, Adama Zan Diarra, Fatou Samba Diouf, Charles Bouganali, Lionel Almeras, Cheikh Sokhna, Georges Diatta and Philippe Parola
Pathogens 2023, 12(9), 1078; https://doi.org/10.3390/pathogens12091078 - 24 Aug 2023
Cited by 1 | Viewed by 2652
Abstract
The soft ticks, Ornithodoros sonrai, are known as vectors of the tick-borne relapsing fever caused by Borrelia spp. and have also been reported to carry other micro-organisms. The objective of this study was to collect and to identify O. sonrai ticks and [...] Read more.
The soft ticks, Ornithodoros sonrai, are known as vectors of the tick-borne relapsing fever caused by Borrelia spp. and have also been reported to carry other micro-organisms. The objective of this study was to collect and to identify O. sonrai ticks and to investigate the micro-organisms associated with them. In 2019, an investigation of burrows within human dwellings was conducted in 17 villages in the Niakhar area and in 15 villages in the Sine-Saloum area in the Fatick region of Senegal. Ticks collected from the burrows were identified morphologically and by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Micro-organism screening was performed by bacteria-specific qPCR and some identifications were made by standard PCR and gene sequencing. O. sonrai ticks were found in 100% (17/17) of the villages surveyed in the Niakhar area and in 66% (10/15) of the villages in the Sine-Saloum area. A total of 1275 soft tick specimens were collected from small mammal burrows. The ticks collected were morphologically identified as O. sonrai. About 20% (259/1275) of the specimens were also submitted to MALDI-TOF MS for identification. Among the resulting MS profiles, 87% (139/159) and 95% (95/100) were considered good quality specimens, preserved in alcohol and silica gel, respectively. All spectra of good quality were tested against our MALDI-TOF MS arthropod spectra database and identified as O. sonrai species, corroborating the morphological classification. The carriage of four micro-organisms was detected in the ticks with a high prevalence of Bartonella spp., Anaplasmataceae, and Borrelia spp. of 35, 28, and 26%, respectively, and low carriage of Coxiella burnetii (2%). This study highlights the level of tick infestation in domestic burrows, the inventory of pathogens associated with the O. sonrai tick, and the concern about the potential risk of tick involvement in the transmission of these pathogens in Senegal. Full article
Show Figures

Figure 1

9 pages, 823 KiB  
Article
Whole Genome Sequencing Shows that African Swine Fever Virus Genotype IX Is Still Circulating in Domestic Pigs in All Regions of Uganda
by Rodney Okwasiimire, Joseph F. Flint, Edrine B. Kayaga, Steven Lakin, Jim Pierce, Roger W. Barrette, Bonto Faburay, Dickson Ndoboli, John E. Ekakoro, Eddie M. Wampande and Karyn A. Havas
Pathogens 2023, 12(7), 912; https://doi.org/10.3390/pathogens12070912 - 6 Jul 2023
Cited by 9 | Viewed by 2251
Abstract
Blood samples were collected from pigs at six abattoirs in the Kampala, Uganda metropolitan area from May 2021 through June 2022, and tested for African swine fever virus. Thirty-one samples with cycle threshold values < 26 from pigs with different geographic origins, clinical [...] Read more.
Blood samples were collected from pigs at six abattoirs in the Kampala, Uganda metropolitan area from May 2021 through June 2022, and tested for African swine fever virus. Thirty-one samples with cycle threshold values < 26 from pigs with different geographic origins, clinical and pathologic signs, and Ornithodoros moubata exposure underwent whole genome sequencing. The p72 gene was used to genotype the isolates, and all were found to be genotype IX; whole genome sequences to previous genotype IX isolates confirmed their similarity. Six of the isolates had enough coverage to evaluate single nucleotide polymorphisms (SNPs). Five of the isolates differed from historic regional isolates, but had similar SNPs to one another, and the sixth isolate also differed from historic regional isolates, but also differed from the other five isolates, even though they are all genotype IX. Whole genome sequencing data provide additional detail on viral evolution that can be useful for molecular epidemiology, and understanding the impact of changes in genes to disease phenotypes, and may be needed for vaccine targeting should a commercial vaccine become available. More sequencing of African swine fever virus isolates is needed in Uganda to understand how and when the virus is changing. Full article
(This article belongs to the Special Issue Emergence and Control of African Swine Fever)
Show Figures

Figure 1

11 pages, 306 KiB  
Article
Artificial Feeding of Ornithodoros fonsecai and O. brasiliensis (Acari: Argasidae) and Investigation of the Transstadial Perpetuation of Anaplasma marginale
by Ana Carolina Castro-Santiago, Leidiane Lima-Duarte, Jaqueline Valeria Camargo, Beatriz Rocha De Almeida, Simone Michaela Simons, Luis Antonio Mathias, Ricardo Bassini-Silva, Rosangela Zacarias Machado, Marcos Rogério André and Darci Moraes Barros-Battesti
Microorganisms 2023, 11(7), 1680; https://doi.org/10.3390/microorganisms11071680 - 28 Jun 2023
Cited by 1 | Viewed by 1618
Abstract
Anaplasma marginale is a Gram-negative, obligate intraerythrocytic bacterium that causes bovine anaplasmosis. While hard ticks of the genera Dermacentor and Rhipicephalus can be biological vectors, transmitting this pathogen via saliva during blood meals, blood-sucking insects, and fomites play a role as mechanical vectors. [...] Read more.
Anaplasma marginale is a Gram-negative, obligate intraerythrocytic bacterium that causes bovine anaplasmosis. While hard ticks of the genera Dermacentor and Rhipicephalus can be biological vectors, transmitting this pathogen via saliva during blood meals, blood-sucking insects, and fomites play a role as mechanical vectors. Little is known about the interaction between Anaplasma marginale and Argasidae ticks. Among soft ticks, Ornithodoros fonsecai (Labruna and Venzal) and Ornithodoros brasiliensis Aragão inhabit environments surrounding localities where many cases of bovine anaplasmosis have been reported. Ticks of the species O. fonsecai parasitize bats, while O. brasiliensis can parasitize different vertebrate species. Therefore, the present study aimed to feed third-instar nymphs artificially (N3) of O. fonsecai and O. brasiliensis using blood samples obtained from a calf naturally infected with A. marginale and rabbit blood added to A. marginale-containing bovine erythrocytes, to investigate the ability of these nymphs to acquire, infect and transstadially perpetuate this agent. For the artificial feeding system, adapted chambers and parafilm membranes were used. Nymphs of both tick species were submitted to different replications weighed before and after each feeding. Blood samples and molted ticks were submitted to DNA extraction, quantitative real-time PCR for the msp1β gene to detect A. marginale DNA, while a semi-nested polymerase chain reaction for the msp1α gene was performed for genotyping. Using calf blood naturally infected with A. marginale, among the three artificial feeding replications performed with O. fonsecai and O. brasiliensis nymphs, the DNA of A. marginale was detected in both nymphs after 30–50 days of molting. For artificial feeding with rabbit blood added to bovine erythrocytes containing A. marginale, the DNA of this pathogen was also detected in both nymph species. As for the assay for the msp1α gene, strains were found Is9; 78 24-2; 25; 23; α; and β. It was concluded that nymphs (N3) of O. fonsecai and O. brasiliensis could feed artificially through a parafilm membrane using blood from calves and rabbits infected by A. marginale. The DNA of A. marginale was detected in nymphs fed artificially of both tick species studied after molt. However, further studies are needed to confirm transstadial perpetuation in other instars and their host transmission capacity. Full article
22 pages, 1583 KiB  
Review
An Updated Review of Ornithodoros Ticks as Reservoirs of African Swine Fever in Sub-Saharan Africa and Madagascar
by Ferran Jori, Armanda Bastos, Fernando Boinas, Juanita Van Heerden, Livio Heath, Hélène Jourdan-Pineau, Beatriz Martinez-Lopez, Rémi Pereira de Oliveira, Thomas Pollet, Carlos Quembo, Keaton Rea, Edgar Simulundu, Florian Taraveau and Mary-Louise Penrith
Pathogens 2023, 12(3), 469; https://doi.org/10.3390/pathogens12030469 - 16 Mar 2023
Cited by 17 | Viewed by 5369
Abstract
This updated review provides an overview of the available information on Ornithodoros ticks as reservoirs and biological vectors of the ASF virus in Africa and Indian Ocean islands in order to update the current knowledge in this field, inclusive of an overview of [...] Read more.
This updated review provides an overview of the available information on Ornithodoros ticks as reservoirs and biological vectors of the ASF virus in Africa and Indian Ocean islands in order to update the current knowledge in this field, inclusive of an overview of available methods to investigate the presence of ticks in the natural environment and in domestic pig premises. In addition, it highlights the major areas of research that require attention in order to guide future investigations and fill knowledge gaps. The available information suggests that current knowledge is clearly insufficient to develop risk-based control and prevention strategies, which should be based on a sound understanding of genotype distribution and the potential for spillover from the source population. Studies on tick biology in the natural and domestic cycle, including genetics and systematics, represent another important knowledge gap. Considering the rapidly changing dynamics affecting the African continent (demographic growth, agricultural expansion, habitat transformation), anthropogenic factors influencing tick population distribution and ASF virus (ASFV) evolution in Africa are anticipated and have been recorded in southern Africa. This dynamic context, together with the current global trends of ASFV dissemination, highlights the need to prioritize further investigation on the acarological aspects linked with ASF ecology and evolution. Full article
Show Figures

Figure 1

16 pages, 2651 KiB  
Article
A Novel Relapsing Fever Group Borrelia Isolated from Ornithodoros Ticks of the Brazilian Caatinga
by Glauber M. B. de Oliveira, Sebastián Muñoz-Leal, Adriana Santodomingo, Barbara C. Weck, Álvaro A. Faccini-Martínez, Maurício C. Horta and Marcelo B. Labruna
Microorganisms 2023, 11(2), 370; https://doi.org/10.3390/microorganisms11020370 - 1 Feb 2023
Cited by 9 | Viewed by 2795
Abstract
Tick-borne relapsing fever group (RFG) borreliosis remains neglected as a human disease and little is known on its maintenance in ticks and vertebrates, especially in South America. Therefore, this study investigated borrelial infection in Ornithodoros ticks collected in rodent-inhabited rock formations in the [...] Read more.
Tick-borne relapsing fever group (RFG) borreliosis remains neglected as a human disease and little is known on its maintenance in ticks and vertebrates, especially in South America. Therefore, this study investigated borrelial infection in Ornithodoros ticks collected in rodent-inhabited rock formations in the Brazilian semiarid region, within the Caatinga biome. Collected ticks (Ornithodoros rietcorreai and Ornithodoros cf. tabajara) were allowed to feed under laboratory conditions on guinea pigs, which had blood samples examined daily by dark-field microscopy. No spirochetes were visualized in the blood of any of four O. rietcorreai-infested guinea pigs. Contrastingly, spirochetes were visualized between 9 and 39 days after tick feeding in the blood of three guinea pigs, each infested with O. cf. tabajara ticks from a different locality. Guinea pig infection was confirmed by passages into experimental animals and by generating DNA sequences of Borrelia spp. from the blood of spirochetemic guinea pigs. Three O. cf. tabajara populations were infected by the same borrelial organism, which was characterized as a novel RFG agent (named as ‘Candidatus Borrelia caatinga’) based on 10 Borrelia loci (rrs, flaB, glpQ, gyrB, clpX, pepX, pyrG, recG, rplB and uvrA). We demonstrated that O. cf. tabajara is a competent vector of the novel Borrelia sp. isolates, although none of the infected rodents developed clinical illness. Full article
(This article belongs to the Special Issue Molecular Epidemiology and Diagnosis of Parasitic Zoonosis)
Show Figures

Figure 1

12 pages, 2495 KiB  
Article
Detection of Old and New World Relapsing Fever Borreliae in Ornithodoros Ticks Collected from Warthog Burrows in Zambia
by Yongjin Qiu, Herman M. Chambaro, Kozue Sato, David Squarre, Edgar Simulundu, Masahiro Kajihara, Katendi Changula, Manyando Simbotwe, Hayato Harima, Joseph Ndebe, Ladslav Moonga, Ryo Nakao, Ayato Takada, Bernard Mudenda Hang’ombe, Hirofumi Sawa and Hiroki Kawabata
Microorganisms 2023, 11(1), 200; https://doi.org/10.3390/microorganisms11010200 - 12 Jan 2023
Viewed by 3022
Abstract
Relapsing fever (RF) is an arthropod-borne disease caused by Borrelia spirochete, which is one of the major public health concerns in endemic regions including Africa. However, information on Borrelia spirochetes is limited in Zambia. Here, we investigate the Borrelia spirochetes harbored by Ornithodoros ticks in [...] Read more.
Relapsing fever (RF) is an arthropod-borne disease caused by Borrelia spirochete, which is one of the major public health concerns in endemic regions including Africa. However, information on Borrelia spirochetes is limited in Zambia. Here, we investigate the Borrelia spirochetes harbored by Ornithodoros ticks in Zambian National Parks. We analyzed 182 DNA samples pooled from 886 Ornithodoros ticks. Of these, 43 tested positive, and their sequence revealed that the ticks harbored both Old and New World RF borreliae. This research presents the first evidence of Old-World RF borreliae in Zambia. The New World RF borreliae detected herein differed from the Candidatus Borrelia fainii previously reported in Zambia and were closely related to the pathogenic Borrelia sp. VS4 identified in Tanzania. Additionally, Borrelia theileri was recently reported in Zambia. Hence, at least four different Borrelia species occur in Zambia, and the organisms causing relapsing fever there might be more complex than previously thought. We empirically confirmed that real-time PCR with TaqMan minor groove binder probes accurately and simultaneously detected both Old and New World RF. In this manner, they could facilitate quantitative analyses of both types of RF borreliae. Subsequent investigations should endeavor to isolate the aforementioned Borrelia spp. and perform serosurveys on patients with RF. Full article
(This article belongs to the Special Issue Research on Ticks and Tick-Borne Pathogens)
Show Figures

Figure 1

21 pages, 6165 KiB  
Article
Comparative Analysis of Tick-Borne Relapsing Fever Spirochaetes from Ethiopia and Nigeria
by Adefolake A. Bankole, Bersissa Kumsa, Gezahegne Mamo, Ndudim I. Ogo, Nusirat Elelu, Winston Morgan and Sally J. Cutler
Pathogens 2023, 12(1), 81; https://doi.org/10.3390/pathogens12010081 - 3 Jan 2023
Cited by 4 | Viewed by 2851
Abstract
Despite increasing reports of tick-borne diseases in Africa, remarkably, reports of tick-borne relapsing fever (TBRF) in Nigeria are lacking. Ornithodoros savignyi from Nigeria have been reported with the relapsing fever Candidatus Borrelia kalaharica. Conversely, in Ethiopia, the agent of relapsing fever is the [...] Read more.
Despite increasing reports of tick-borne diseases in Africa, remarkably, reports of tick-borne relapsing fever (TBRF) in Nigeria are lacking. Ornithodoros savignyi from Nigeria have been reported with the relapsing fever Candidatus Borrelia kalaharica. Conversely, in Ethiopia, the agent of relapsing fever is the louse-borne relapsing fever (LBRF) spirochaete Borrelia recurrentis with no TBRF reported to occur. A total of 389 Ornithodoros ticks, Ethiopia (N = 312) and Nigeria (N = 77), were sampled, together with 350 cattle, and 200 goat sera were collected from Nigeria. Samples were screened for Borrelia spp. by RT-PCR. Reactive samples were confirmed, then sequenced using flagellin B, 16S rRNA, and 16S–23S intergenic spacer region. The prevalence of Borrelia spp. in livestock was 3.8% (21/550) and 14% (3/21) after final molecular confirmation. Of 312 ticks from Ethiopia, 3.5% (11/312) were positive for Borrelia, with 36% (4/11) by conventional PCR. Sequencing revealed that the borreliae in soft ticks was C. B. kalaharica, whilst that found in animals was Borrelia theileri. Soft ticks were confirmed by sequencing 7% (22/312) and 12% (9/77) of the Ethiopian and Nigerian ticks, respectively. Phylogenetic analysis revealed that these were Ornithodoros savignyi. This is the first evidence of C. B. kalaharica in Ethiopia and demonstrates the co-existence of TBRF in a country endemic to LBRF. Important, this might cause a diagnostic challenge given that LBRF is predominantly diagnosed by microscopy, which cannot differentiate these two spirochaetes. Furthermore, we report B. theileri in ruminants in Nigeria, which may also be of veterinary and economic importance. Full article
(This article belongs to the Special Issue Zoonotic Disease Threats and Interventions)
Show Figures

Figure 1

11 pages, 1418 KiB  
Article
Pathogen Detection in Ornithodoros sonrai Ticks and Invasive House Mice Mus musculus domesticus in Senegal
by Basma Ouarti, Moussa Sall, El Hadji Ibrahima Ndiaye, Georges Diatta, Adama Zan Diarra, Jean Michel Berenger, Cheikh Sokhna, Laurent Granjon, Jean Le Fur and Philippe Parola
Microorganisms 2022, 10(12), 2367; https://doi.org/10.3390/microorganisms10122367 - 30 Nov 2022
Cited by 5 | Viewed by 2111
Abstract
Ornithodoros sonrai (O. sonrai) ticks are the only known vectors of Borrelia crocidurae, an agent of tick-borne relapsing fever (TBRF) borreliosis. Rodents serve as principal natural reservoirs for Borrelia. Our research objective was to detect TBRF Borrelia and other [...] Read more.
Ornithodoros sonrai (O. sonrai) ticks are the only known vectors of Borrelia crocidurae, an agent of tick-borne relapsing fever (TBRF) borreliosis. Rodents serve as principal natural reservoirs for Borrelia. Our research objective was to detect TBRF Borrelia and other zoonotic bacterial infections in ticks and in house mice Mus musculus domesticus, an invasive species currently expanding in rural northern Senegal. Real-time and conventional PCR were utilized for detecting Borrelia and other bacterial taxa. The analyses were performed on 253 specimens of O. sonrai and 150 samples of brain and spleen tissue from rodents. Borrelia crocidurae was found in one O. sonrai tick and 18 Mus musculus domesticus samples, with prevalences of 0.39 percent and 12 percent, respectively, as well as Ehrlichia sp. in one Mus musculus domesticus. Further, we were able to detect the presence of a potentially infectious novel species belonging to the Anaplasmataceae family for the first time in O. sonrai ticks. More attention should be paid to the house mouse and O. sonrai ticks, as they can be potential hosts for novel species of pathogenic bacteria in humans. Full article
(This article belongs to the Special Issue Ticks and Tick-Borne Diseases in Animals)
Show Figures

Figure 1

23 pages, 12524 KiB  
Article
Detection of African Swine Fever Virus in Ornithodoros Tick Species Associated with Indigenous and Extralimital Warthog Populations in South Africa
by Anthony F. Craig, Mathilde L. Schade-Weskott, Thapelo Rametse, Livio Heath, Gideon J. P. Kriel, Lin-Mari de Klerk-Lorist, Louis van Schalkwyk, Jessie D. Trujillo, Jan E. Crafford, Juergen A. Richt and Robert Swanepoel
Viruses 2022, 14(8), 1617; https://doi.org/10.3390/v14081617 - 26 Jul 2022
Cited by 5 | Viewed by 3538
Abstract
We investigated the possibility that sylvatic circulation of African swine fever virus (ASFV) in warthogs and Ornithodoros ticks had extended beyond the historically affected northern part of South Africa that was declared a controlled area in 1935 to prevent the spread of infection [...] Read more.
We investigated the possibility that sylvatic circulation of African swine fever virus (ASFV) in warthogs and Ornithodoros ticks had extended beyond the historically affected northern part of South Africa that was declared a controlled area in 1935 to prevent the spread of infection to the rest of the country. We recently reported finding antibody to the virus in extralimital warthogs in the south of the country, and now describe the detection of infected ticks outside the controlled area. A total of 5078 ticks was collected at 45 locations in 7/9 provinces during 2019–2021 and assayed as 711 pools for virus content by qPCR, while 221 pools were also analysed for tick phylogenetics. Viral nucleic acid was detected in 50 tick pools representing all four members of the Ornithodoros (Ornithodoros) moubata complex known to occur in South Africa: O. (O.) waterbergensis and O. (O.) phacochoerus species yielded ASFV genotypes XX, XXI, XXII at 4 locations and O. (O.) moubata yielded ASFV genotype I at two locations inside the controlled area. Outside the controlled area, O. (O.) moubata and O. (O.) compactus ticks yielded ASFV genotype I at 7 locations, while genotype III ASFV was identified in O. (O.) compactus ticks at a single location. Two of the three species of the O. (O.) savignyi complex ticks known to be present in the country, O. (O.) kalahariensis and O. (O.) noorsveldensis, were collected at single locations and found negative for virus. The only member of the Pavlovskyella subgenus of Ornithodoros ticks known to occur in South Africa, O. (P.) zumpti, was collected from warthog burrows for the first time, in Addo National Park in the Eastern Cape Province where ASFV had never been recorded, and it tested negative for the viral nucleic acid. While it is confirmed that there is sylvatic circulation of ASFV outside the controlled area in South Africa, there is a need for more extensive surveillance and for vector competence studies with various species of Ornithodoros ticks. Full article
(This article belongs to the Special Issue African Swine Fever and Other Swine Viral Diseases in Africa)
Show Figures

Figure 1

Back to TopTop