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1.
BMC Public Health ; 24(1): 1031, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38614967

RESUMO

BACKGROUND: Urban green spaces are important for human health, but they may expose visitors to tick-borne diseases. This not only presents a potential public health challenge but also undermines the expected public health gains from urban green spaces. The aim of this study is to assess the public health risk of tick-borne diseases in an urban green space used for recreation in Stockholm, Sweden. METHODS: We used a mixed method approach identifying both the magnitude of the tick hazard and the extent of the human exposure to tick-borne diseases. At six entry points to an urban green space, we sampled ticks and documented microhabitat conditions from five randomly assigned 2 m × 2 m plots. Surrounding habitat data was analyzed using geographical information system (GIS). Nymphs and adult ticks were tested for Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum using TaqMan qPCR. Positive B. burgdorferi (s.l.) ticks were further analyzed by nested PCR amplification and sequence analysis. Population census data and visitor count data were used to estimate the degree of human exposure to tick-borne diseases. To further understand the degree to which visitors get in contact with infected ticks we also conducted interviews with visitors to green spaces. RESULTS: High tick densities were commonly found in humid broadleaved forest with low field vegetation. High pathogen prevalence was significantly correlated with increasing proportions of artificial areas. Integrating the tick hazard with human exposure we found that the public health risk of tick-borne diseases was moderate to high at most of the studied entry points. Many of the visitors frequently used urban green spaces. Walking was the most common activity, but visitors also engaged in activities with higher risk for tick encounters. Individual protective measures were connected to specific recreational activities such as picking berries or mushrooms. CONCLUSIONS: The number of visitors can be combined with tick inventory data and molecular analyses of pathogen prevalence to make crude estimations of the public health risk of tick-borne diseases in urban green spaces. The risk of encountering infected ticks is omnipresent during recreational activities in urban green spaces, highlighting the need for public health campaigns to reduce the risk of tick-borne diseases.


Assuntos
Doenças Transmitidas por Carrapatos , Carrapatos , Adulto , Animais , Humanos , Saúde Pública , Parques Recreativos , Promoção da Saúde , Doenças Transmitidas por Carrapatos/epidemiologia
2.
Front Cell Infect Microbiol ; 14: 1334351, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38567020

RESUMO

Most tick-borne viruses (TBVs) are highly pathogenic and require high biosecurity, which severely limits their study. We found that Sindbis virus (SINV), predominantly transmitted by mosquitoes, can replicate in ticks and be subsequently transmitted, with the potential to serve as a model for studying tick-virus interactions. We found that both larval and nymphal stages of Rhipicephalus haemaphysaloides can be infected with SINV-wild-type (WT) when feeding on infected mice. SINV replicated in two species of ticks (R. haemaphysaloides and Hyalomma asiaticum) after infecting them by microinjection. Injection of ticks with SINV expressing enhanced Green Fluorescent Protein (eGFP) revealed that SINV-eGFP specifically aggregated in the tick midguts for replication. During blood-feeding, SINV-eGFP migrated from the midguts to the salivary glands and was transmitted to a new host. SINV infection caused changes in expression levels of tick genes related to immune responses, substance transport and metabolism, cell growth and death. SINV mainly induced autophagy during the early stage of infection; with increasing time of infection, the level of autophagy decreased, while the level of apoptosis increased. During the early stages of infection, the transcript levels of immune-related genes were significantly upregulated, and then decreased. In addition, SINV induced changes in the transcription levels of some functional genes that play important roles in the interactions between ticks and tick-borne pathogens. These results confirm that the SINV-based transmission model between ticks, viruses, and mammals can be widely used to unravel the interactions between ticks and viruses.


Assuntos
Carrapatos , Vírus , Animais , Camundongos , Vírus Sindbis/genética , Mosquitos Vetores , Mamíferos
3.
Parasit Vectors ; 17(1): 167, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38566227

RESUMO

BACKGROUND: Hyalomma ticks are widely distributed in semi-arid zones in Northwest China. They have been reported to harbor a large number of zoonotic pathogens. METHODS: In this study, a total of 334 Hyalomma asiaticum ticks infesting domestic animals were collected from four locations in Xinjiang, Northwest China, and the bacterial agents in them were investigated. RESULTS: A putative novel Borrelia species was identified in ticks from all four locations, with an overall positive rate of 6.59%. Rickettsia sibirica subsp. mongolitimonae, a human pathogen frequently reported in Europe, was detected for the second time in China. Two Ehrlichia species (Ehrlichia minasensis and Ehrlichia sp.) were identified. Furthermore, two Anaplasma species were characterized in this study: Candidatus Anaplasma camelii and Anaplasma sp. closely related to Candidatus Anaplasma boleense. It is the first report of Candidatus Anaplasma camelii in China. CONCLUSIONS: Six bacterial agents were reported in this study, many of which are possible or validated pathogens for humans and animals. The presence of these bacterial agents may suggest a potential risk for One Health in this area.


Assuntos
Ixodidae , Rickettsia , Doenças Transmitidas por Carrapatos , Carrapatos , Animais , Humanos , Carrapatos/microbiologia , Doenças Transmitidas por Carrapatos/microbiologia , Rickettsia/genética , Ixodidae/microbiologia , Ehrlichia , Anaplasma , China
4.
Vet Med Sci ; 10(3): e1434, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38567942

RESUMO

BACKGROUND: No tick-borne pathogens (TBPs) causing haemolytic anaemia in cattle have been reported, except Theileria orientalis and complete blood count (CBC) profile is the only haematological parameter to determine the severity of regenerative haemolytic anaemia. OBJECTIVES: To identify the causative agents of TBP-induced haemolytic anaemia and determine haematological parameters that indicate haemolytic anaemia in grazing cattle. METHODS: Eighty-two Korean indigenous cattle (Hanwoo) were divided into two groups: grazing (n = 67) and indoor (n = 15) groups. CBC and serum biochemistry were performed. PCR was conducted using whole blood-extracted DNA to investigate the prevalence of TBPs. RESULTS: TBP-induced haemolytic anaemia was observed in the grazing group. In grazing cattle, co-infection (43.3%, 29/67) was most frequently detected, followed by T. orientalis (37.6%, 25/67) and Anaplasma phagocytophilum infections (1.5%, 1/67). In indoor cattle, only co-infection (20%, 3/15) was identified. Grazing cattle exhibited regenerative haemolytic anaemia with marked monocytosis, mild neutropenia, and thrombocytopenia. According to grazing frequency, the 1st-time grazing group had more severe anaemia than the 2nd-time grazing group. Elevations in indirect bilirubin and L-lactate due to haemolytic anaemia were identified, and correlations with the respective markers were determined in co-infected grazing cattle. CONCLUSIONS: Quantitative evaluation of haematocrit, mean corpuscular volume, and reticulocytes (markers of regenerative haemolytic anaemia in cattle) was performed for the first time. Our results show that, in addition to T. orientalis, A. phagocytophilum is strongly associated with anaemia. The correlation between haemolytic anaemia severity and haematological parameters (indirect bilirubin, reticulocytes, and L-lactate) was confirmed.


Assuntos
Anemia Hemolítica , Doenças dos Bovinos , Coinfecção , Theileriose , Carrapatos , Bovinos , Animais , Theileriose/epidemiologia , Doenças dos Bovinos/epidemiologia , Coinfecção/veterinária , Anemia Hemolítica/etiologia , Anemia Hemolítica/veterinária , Bilirrubina , Lactatos
5.
Emerg Med Clin North Am ; 42(2): 287-302, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38641392

RESUMO

Ticks are responsible for the vast majority of vector-borne illnesses in the United States. The number of reported tick-borne disease (TBD) cases has more than doubled in the past 20 years. The majority of TBD cases occur in warm weather months in individuals with recent outdoor activities in wooded areas. The risk of contracting a TBD is also highly dependent on geographic location. Between 24 and 48 hours of tick attachment is required for most disease transmission to occur. Only 50% to 70% of patients with a TBD will recall being bitten by a tick, and TBDs are often initially misdiagnosed as a viral illness. Most TBDs are easily treated when diagnosed early in their course.


Assuntos
Ehrlichiose , Doenças Transmitidas por Carrapatos , Carrapatos , Animais , Humanos , Estados Unidos/epidemiologia , Ehrlichiose/diagnóstico , Ehrlichiose/terapia , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/terapia
6.
Biomed Environ Sci ; 37(3): 266-277, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38582991

RESUMO

Objective: The purpose of this study was to investigate the bacterial communities of biting midges and ticks collected from three sites in the Poyang Lake area, namely, Qunlu Practice Base, Peach Blossom Garden, and Huangtong Animal Husbandry, and whether vectors carry any bacterial pathogens that may cause diseases to humans, to provide scientific basis for prospective pathogen discovery and disease prevention and control. Methods: Using a metataxonomics approach in concert with full-length 16S rRNA gene sequencing and operational phylogenetic unit (OPU) analysis, we characterized the species-level microbial community structure of two important vector species, biting midges and ticks, including 33 arthropod samples comprising 3,885 individuals, collected around Poyang Lake. Results: A total of 662 OPUs were classified in biting midges, including 195 known species and 373 potentially new species, and 618 OPUs were classified in ticks, including 217 known species and 326 potentially new species. Surprisingly, OPUs with potentially pathogenicity were detected in both arthropod vectors, with 66 known species of biting midges reported to carry potential pathogens, including Asaia lannensis and Rickettsia bellii, compared to 50 in ticks, such as Acinetobacter lwoffii and Staphylococcus sciuri. We found that Proteobacteria was the most dominant group in both midges and ticks. Furthermore, the outcomes demonstrated that the microbiota of midges and ticks tend to be governed by a few highly abundant bacteria. Pantoea sp7 was predominant in biting midges, while Coxiella sp1 was enriched in ticks. Meanwhile, Coxiella spp., which may be essential for the survival of Haemaphysalis longicornis Neumann, were detected in all tick samples. The identification of dominant species and pathogens of biting midges and ticks in this study serves to broaden our knowledge associated to microbes of arthropod vectors. Conclusion: Biting midges and ticks carry large numbers of known and potentially novel bacteria, and carry a wide range of potentially pathogenic bacteria, which may pose a risk of infection to humans and animals. The microbial communities of midges and ticks tend to be dominated by a few highly abundant bacteria.


Assuntos
Ceratopogonidae , Microbiota , Carrapatos , Animais , Humanos , Carrapatos/microbiologia , Ceratopogonidae/genética , Filogenia , RNA Ribossômico 16S/genética , Estudos Prospectivos , Coxiella/genética
7.
J Parasitol ; 110(2): 155-158, 2024 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-38621699

RESUMO

Eight ticks were found in Comacchio (FE), Italy parasitizing a young black iguana (Ctenosaura similis) that had been accidentally transported in a commercial plant container from Costa Rica. Specimens were identified morphologically as Amblyomma scutatum and then confirmed by the barcoding of the mitochondrial cytochrome c oxidase subunit 1 gene. Amblyomma scutatum is a common tick known to infest reptiles in Central America, Mexico, and Venezuela, but not in Europe. In Italy, the possibility for this tick to become endemic is unlikely because of the absence of its principal hosts. Nevertheless, this finding confirms the high risk of introducing exotic species that is linked with global commerce and therefore the need for veterinary control of shipments.


Assuntos
Ixodidae , Lagartos , Infestações por Carrapato , Carrapatos , Animais , Ixodidae/genética , Amblyomma , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/veterinária , Itália
8.
PLoS One ; 19(4): e0296127, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38626020

RESUMO

Lyme disease is the most prevalent vector-borne infectious disease in Europe and the USA. Borrelia burgdorferi, as the causative agent of Lyme disease, is transmitted to the mammalian host during the tick blood meal. To adapt to the different encountered environments, Borrelia has adjusted the expression pattern of various, mostly outer surface proteins. The function of most B. burgdorferi outer surface proteins remains unknown. We determined the crystal structure of a previously uncharacterized B. burgdorferi outer surface protein BBK01, known to belong to the paralogous gene family 12 (PFam12) as one of its five members. PFam12 members are shown to be upregulated as the tick starts its blood meal. Structural analysis of BBK01 revealed similarity to the coiled coil domain of structural maintenance of chromosomes (SMC) protein family members, while functional studies indicated that all PFam12 members are non-specific DNA-binding proteins. The residues involved in DNA binding were identified and probed by site-directed mutagenesis. The combination of SMC-like proteins being attached to the outer membrane and exposed to the environment or located in the periplasm, as observed in the case of PFam12 members, and displaying the ability to bind DNA, represents a unique feature previously not observed in bacteria.


Assuntos
Borrelia burgdorferi , Doença de Lyme , Carrapatos , Animais , Borrelia burgdorferi/genética , Borrelia burgdorferi/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Doença de Lyme/microbiologia , Carrapatos/genética , Proteínas de Membrana/metabolismo , DNA/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Mamíferos/genética
9.
PLoS One ; 19(4): e0299002, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38626086

RESUMO

Tropical theileriosis is a fatal leukemic-like disease of cattle caused by the tick-transmitted protozoan parasite Theileria annulata. The economics of cattle meat and milk production is severely affected by theileriosis in endemic areas. The hydroxynaphtoquinone buparvaquone (BPQ) is the only available drug currently used to treat clinical theileriosis, whilst BPQ resistance is emerging and spreading in endemic areas. Here, we chronically exposed T. annulata-transformed macrophages in vitro to BPQ and monitored the emergence of drug-resistant parasites. Surviving parasites revealed a significant increase in BPQ IC50 compared to the wild type parasites. Drug resistant parasites from two independent cloned lines had an identical single mutation, M128I, in the gene coding for T. annulata cytochrome B (Tacytb). This in vitro generated mutation has not been reported in resistant field isolates previously, but is reminiscent of the methionine to isoleucine mutation in atovaquone-resistant Plasmodium and Babesia. The M128I mutation did not appear to exert any deleterious effect on parasite fitness (proliferation and differentiation to merozoites). To gain insight into whether drug-resistance could have resulted from altered drug binding to TaCytB we generated in silico a 3D-model of wild type TaCytB and docked BPQ to the predicted 3D-structure. Potential binding sites cluster in four areas of the protein structure including the Q01 site. The bound drug in the Q01 site is expected to pack against an alpha helix, which included M128, suggesting that the change in amino acid in this position may alter drug-binding. The in vitro generated BPQ resistant T. annulata is a useful tool to determine the contribution of the various predicted docking sites to BPQ resistance and will also allow testing novel drugs against theileriosis for their potential to overcome BPQ resistance.


Assuntos
Antiprotozoários , Naftoquinonas , Parasitos , Theileria annulata , Theileriose , Carrapatos , Animais , Bovinos , Theileriose/tratamento farmacológico , Theileriose/parasitologia , Theileria annulata/genética , Citocromos b/genética , Isoleucina/farmacologia , Metionina/farmacologia , Antiprotozoários/farmacologia , Mutação , Racemetionina/farmacologia , Antiparasitários/farmacologia , Carrapatos/parasitologia
10.
Front Cell Infect Microbiol ; 14: 1355113, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38500499

RESUMO

Tularemia is a vector-borne disease caused by the Gram-negative bacterium Francisella tularensis. Known hosts and vectors in Europe are hare and ticks. F. tularensis is transmitted from ticks and animals, but also from the hydrotelluric environment and the consumption of contaminated water or food. A changing climate expands the range in which ticks can live and consequently might contribute to increasing case numbers of tularemia. Two subspecies of F. tularensis are human pathogenic. Francisella tularensis tularensis (Ftt) is endemic in North America, while Francisella tularensis holarctica (Fth) is the only subspecies causing tularemia in Europe. Ft is classified as a category A bioterrorism agent due to its low infectious dose, multiple modes of transmission, high infectivity and potential for airborne transmission and has become a global public health concern. In line with the European survey and previous phylogenetic studies, Switzerland shows the co-distribution of B.6 and B.12 strains with different geographical distribution and prevalence within the country. To establish itself in different host environments of ticks and mammals, F. tularensis presumably undergoes substantial changes on the transcriptomics and proteomic level. Here we investigate the transcriptomic and proteomic differences of five strains of Fth upon infection of rabbit macrophages and tick cells.


Assuntos
Francisella tularensis , Francisella , Proteogenômica , Carrapatos , Tularemia , Animais , Humanos , Coelhos , Tularemia/microbiologia , Filogenia , Proteômica , Genótipo , Mamíferos
11.
East Mediterr Health J ; 30(2): 145-155, 2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38491900

RESUMO

Background: Tick-borne rickettsioses have become a health concern worldwide following the increasing incidence in recent decades. However, there is limited information about these diseases in Islamic Republic of Iran. Aim: This cross-sectional study was conducted to estimate the Rickettsia infection among ixodid ticks collected from cattle, sheep and goats in Islamic Republic of Iran. Methods: The DNA of ixodid ticks collected from cattle, sheep and goats in 54 villages of Zanjan Province, Islamic Republic of Iran, were collected and analysed using a spectrophotometer. Rickettsial-positive samples were screened by targeting the htrA gene and fragments of gltA gene were analysed. The variables were analysed using descriptive statistics and the χ2 test was used to compare the variables. Results: A total of 528 ticks were tested. Overall, Rickettsia infection rate was 6.44%. Nine of the 12 tick species were infected. Rickettsial positive rates in Hyalomma marginatum and Dermacentor marginatus were 21.33% and 12.77%, respectively. R. aeschlimannii, the predominant rickettsia, was detected only in Hy. marginatum. R. raoultii, R. sibirica and R. slovaca comprised about half of the positive ticks and were recovered from more than one tick species. Conclusion: Considering the discovery of infected ticks in the Islamic Republic of Iran, there is a need to establish a tick control programme in the country, paying attention to populations at high-risk.


Assuntos
Ixodidae , Infecções por Rickettsia , Rickettsia , Rickettsiose do Grupo da Febre Maculosa , Carrapatos , Animais , Humanos , Bovinos , Ovinos , Irã (Geográfico)/epidemiologia , Estudos Transversais , DNA Bacteriano/genética , Rickettsiose do Grupo da Febre Maculosa/epidemiologia , Rickettsiose do Grupo da Febre Maculosa/microbiologia , Rickettsia/genética , Infecções por Rickettsia/epidemiologia , Infecções por Rickettsia/veterinária , Infecções por Rickettsia/microbiologia , Carrapatos/genética , Carrapatos/microbiologia , Cabras
12.
J Virol ; 98(4): e0013224, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38511932

RESUMO

Heartland virus (HRTV) is an emerging tick-borne bandavirus that causes a febrile illness of varying severity in humans, with cases reported in eastern and midwestern regions of the United States. No vaccines or approved therapies are available to prevent or treat HRTV disease. Here, we describe the genetic changes, natural history of disease, and pathogenesis of a mouse-adapted HRTV (MA-HRTV) that is uniformly lethal in 7- to 8-week-old AG129 mice at low challenge doses. We used this model to assess the efficacy of the ribonucleoside analog, 4'-fluorouridine (EIDD-2749), and showed that once-daily oral treatment with 3 mg/kg of drug, initiated after the onset of disease, protects mice against lethal MA-HRTV challenge and reduces viral loads in blood and tissues. Our findings provide insights into HRTV virulence and pathogenesis and support further development of EIDD-2749 as a therapeutic intervention for HRTV disease. IMPORTANCE: More than 60 cases of HRTV disease spanning 14 states have been reported to the United States Centers for Disease Control and Prevention. The expanding range of the Lone Star tick that transmits HRTV, the growing population of at-risk persons living in geographic areas where the tick is abundant, and the lack of antiviral treatments or vaccines raise significant public health concerns. Here, we report the development of a new small-animal model of lethal HRTV disease to gain insight into HRTV pathogenesis and the application of this model for the preclinical development of a promising new antiviral drug candidate, EIDD-2749. Our findings shed light on how the virus causes disease and support the continued development of EIDD-2749 as a therapeutic for severe cases of HRTV infection.


Assuntos
Doenças dos Animais , Infecções por Bunyaviridae , Bunyaviridae , Phlebovirus , Carrapatos , Nucleotídeos de Uracila , Humanos , Animais , Estados Unidos , Camundongos , Phlebovirus/genética
13.
Vaccine ; 42(11): 2801-2809, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38508929

RESUMO

Ticks as obligate blood-feeding arthropod vectors of pathogenic viruses, bacteria, protozoa and helminths associated with prevalent tick-borne diseases (TBDs) worldwide. These arthropods constitute the second vector after mosquitoes that transmit pathogens to humans and the first vector in domestic animals. Vaccines constitute the safest and more effective approach to control tick infestations and TBDs, but research is needed to identify new antigens and improve vaccine formulations. The tick protein Subolesin (Sub) is a well-known vaccine protective antigen with a highly conserved sequence at both gene and protein levels in the Ixodidae and among arthropods and vertebrates. In this study, transcriptomics and proteomics analyses were conducted together with graph theory data analysis in wild type and Sub knockdown (KD) tick ISE6 cells in order to identify and characterize the functional implications of Sub in tick cells. The results support a key role for Sub in the regulation of gene expression in ticks and the relevance of this antigen in vaccine development against ticks and TBDs. Proteins with differential representation in response to Sub KD provide insights into vaccine protective mechanisms and candidate tick protective antigens.


Assuntos
Infestações por Carrapato , Doenças Transmitidas por Carrapatos , Carrapatos , Vacinas , Animais , Humanos , Carrapatos/microbiologia , Mosquitos Vetores , Antígenos , Infestações por Carrapato/prevenção & controle , Proteínas de Artrópodes/genética , Doenças Transmitidas por Carrapatos/prevenção & controle
14.
J Med Virol ; 96(4): e29567, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38546093

RESUMO

Emerging pathogenic tick-borne viruses (TBVs) have attracted a great deal of attention due to their significant impact on human and animal health. A novel orthonairovirus named Dadong virus (DDV) was isolated from Haemaphysalis concinna ticks in the Changbai Mountain region on the China-North Korea border. DDV can induce cytopathic effects in mammalian and human cell lines. Phylogenetic analysis showed that it belongs to the genus Orthonairovirus, family Nairoviridae, exhibiting 72.4%-81.3% nucleic acid identity to Tofla orthonairovirus, known to cause lethal infection in IFNAR KO mice. The first serological evidence of DDV circulating in cattle and mice was also obtained, with 4.0% (1/25) of cattle and 2.27% (1/44) of mice seropositive for DDV. Further investigations, including serological surveys using human samples, are required to assess the public health risk posed by DDV.


Assuntos
Vírus de RNA , Carrapatos , Vírus , Animais , Humanos , Bovinos , Camundongos , República Democrática Popular da Coreia , Filogenia , Mamíferos
15.
Parasit Vectors ; 17(1): 164, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38555448

RESUMO

BACKGROUND: The immunocompetence handicap hypothesis suggests that males with a higher testosterone level should be better at developing male secondary traits, but at a cost of suppressed immune performance. As a result, we should expect that males with an increased testosterone level also possess a higher parasite load. However, previous empirical studies aimed to test this prediction have generated mixed results. Meanwhile, the effect of testosterone level on parasite load in female hosts remains poorly known. METHODS: In this study, we tested this prediction by manipulating testosterone level in Daurian ground squirrels (Spermophilus dauricus), a medium-sized rodent widely distributed in northeast Asia. S. dauricus is an important host of ticks and fleas and often viewed as a considerable reservoir of plague. Live-trapped S. dauricus were injected with either tea oil (control group) or testosterone (treatment group) and then released. A total of 10 days later, the rodents were recaptured and checked for ectoparasites. Fecal samples were also collected to measure testosterone level of each individual. RESULTS: We found that testosterone manipulation and sex of hosts interacted to affect tick load. At the end of the experiment, male squirrels subjected to testosterone implantation had an averagely higher tick load than males from the control group. However, this pattern was not found in females. Moreover, testosterone manipulation did not significantly affect flea load in S. dauricus. CONCLUSIONS: Our results only lent limited support for the immunocompetence handicap hypothesis, suggesting that the role of testosterone on regulating parasite load is relatively complex, and may largely depend on parasite type and gender of hosts.


Assuntos
Infestações por Pulgas , Doenças dos Roedores , Sifonápteros , Carrapatos , Animais , Feminino , Masculino , Sciuridae/parasitologia , Infestações por Pulgas/veterinária , Testosterona/fisiologia , Imunocompetência/fisiologia
16.
PLoS Pathog ; 20(3): e1012101, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38502642

RESUMO

Emerging and reemerging tick-borne virus infections caused by orthonairoviruses (family Nairoviridae), which are genetically distinct from Crimean-Congo hemorrhagic fever virus, have been recently reported in East Asia. Here, we have established a mouse infection model using type-I/II interferon receptor-knockout mice (AG129 mice) both for a better understanding of the pathogenesis of these infections and validation of antiviral agents using Yezo virus (YEZV), a novel orthonairovirus causing febrile illnesses associated with tick bites in Japan and China. YEZV-inoculated AG129 mice developed hepatitis with body weight loss and died by 6 days post infection. Blood biochemistry tests showed elevated liver enzyme levels, similar to YEZV-infected human patients. AG129 mice treated with favipiravir survived lethal YEZV infection, demonstrating the anti-YEZV effect of this drug. The present mouse model will help us better understand the pathogenicity of the emerging tick-borne orthonairoviruses and the development of specific antiviral agents for their treatment.


Assuntos
Vírus da Febre Hemorrágica da Crimeia-Congo , Febre Hemorrágica da Crimeia , Nairovirus , Doenças Transmitidas por Carrapatos , Carrapatos , Animais , Humanos , Camundongos , Febre Hemorrágica da Crimeia/patologia , Modelos Animais de Doenças , Antivirais/farmacologia , Antivirais/uso terapêutico , Camundongos Knockout
17.
Parasit Vectors ; 17(1): 160, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38549117

RESUMO

BACKGROUND: Equine piroplasmosis is caused by two tick-borne protozoan parasites, Theileria equi and Babesia caballi,, which are clinically relevant in susceptible horses, donkeys, and mules. Moreover, equine piroplasmosis significantly constrains international trading and equestrian events. Rapidly diagnosing both parasites in carrier animals is essential for implementing effective control measures. Here, a rapid immunochromatographic test for the simultaneous detection of antibodies to T. equi and B. caballi was evaluated using samples from horses and donkeys collected in Greece, Israel, and Italy. The results were compared with an improved competitive enzyme-linked immunosorbent assay (cELISA) for detecting antibodies to both parasites using the same panel of samples. METHODS: Blood samples were collected from 255 horses and donkeys. The panel consisted of 129 horses sampled at four locations in northern Greece, 105 donkeys sampled at four locations in Sicily, and 21 horses sampled at two locations in Israel. The rapid test and the cELISA were performed according to the manufacturer's instructions, and the results were subjected to a statistical analysis to determine the sensitivity and specificity of both tests and their association. RESULTS: The immunochromatographic test provided a result within 15 min and can be performed in the field, detecting both pathogens simultaneously. The overall coincidence rate between the rapid test and the cELISA for detecting antibodies against T. equi was 93% and 92.9% for B. caballi. The rapid test's sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for T. equi were above 91.5%. Sixteen samples were positive for both parasites in the rapid test and eight in the cELISA. Either test had no significant association between T. equi and B. caballi detection. The detection rates of both parasites were significantly higher in Italy than in Greece or Israel and in donkeys than in horses. The agreement for T. equi between the results of both tests was high in Greece (93.8%) and Italy (95.2%) and moderate in Israel (76.2%). For B. caballi, the specificity and NPV of the rapid test were high (94.2% and 98.3%, respectively), although the sensitivity and PPV were moderate (69.2% and 39.1%, respectively) due to the small sample size. However, for B. caballi, the sensitivity was higher with the rapid test. CONCLUSIONS: The rapid test detected T. equi and B. caballi simultaneously in the field, potentially replacing laborious cELISA testing and is recommended for import/export purposes. The test can also be helpful for the differential diagnosis of clinical cases, since seropositivity may rule out equine piroplasmosis since it does not indicate current or active infection.


Assuntos
Babesia , Babesiose , Doenças dos Bovinos , Doenças dos Cavalos , Theileria , Theileriose , Carrapatos , Cavalos , Animais , Bovinos , Equidae , Babesiose/parasitologia , Theileriose/parasitologia , Anticorpos , Carrapatos/parasitologia , Sicília , Doenças dos Cavalos/parasitologia
18.
Ticks Tick Borne Dis ; 15(3): 102329, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38484538

RESUMO

Maps of the distribution of medically-important ticks throughout the US remain lacking in spatial and temporal resolution in many areas, leading to holes in our understanding of where and when people are at risk of tick encounters, an important baseline for informing public health response. In this work, we demonstrate the use of Bayesian Experimental Design (BED) in planning spatiotemporal surveillance of disease vectors. We frame survey planning as an optimization problem with the objective of identifying a calendar of sampling locations that maximizes the expected information regarding some goal. Here we consider the goals of understanding associations between environmental factors and tick presence and minimizing uncertainty in high risk areas. We illustrate our proposed BED workflow using an ongoing tick surveillance study in South Carolina parks. Following a model comparison study based on two years of initial data, several techniques for finding optimal surveys were compared to random sampling. Two optimization algorithms found surveys better than all replications of random sampling, while a space-filling heuristic performed favorably as well. Further, optimal surveys of just 20 visits were more effective than repeating the schedule of 111 visits used in 2021. We conclude that BED shows promise as a flexible and rigorous means of survey design for vector control, and could help alleviate pressure on local agencies by limiting the resources necessary for accurate information on arthropod distributions. We have made the code for our BED workflow publicly available on Zenodo to help promote the application of these methods to future surveillance efforts.


Assuntos
Carrapatos , Animais , Humanos , Estados Unidos , Teorema de Bayes , Sudeste dos Estados Unidos/epidemiologia
19.
Arch Microbiol ; 206(4): 149, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38466437

RESUMO

Domestic yak (Bos grunniens) is an economically important feature of the mountainous region of Gilgit-Baltistan in Pakistan where agriculture is restricted and yaks play multiple roles which includes being a source of milk, meat, hides, fuel and power. However little is known about the parasitic infections in Pakistani yaks. Aim of this research was to report the prevalence and genetic diversity of protozoa parasite (Theileria ovis, 18 S rDNA gene was targeted) and an obligate bacterium (Anaplasma marginale, msp-1 gene was amplified) in the blood that was sampled from 202 yaks collected from four districts in Gilgit-Baltistan during January 2023 till January 2024. Results revealed that 6/202 (3%) yaks were of Theileria ovis while 8/202 (4%) were Anaplasma marginale infected. Positive PCR products of both parasites were confirmed by DNA sequencing and their similarity with previously available pathogen sequences was determined by BLAST analysis. Phylogenetic tree indicated that isolates of both parasites displayed genetic. Anaplasma marginale infection varied with the sampling districts and Shigar district had the highest rate of bacterial infection. Cows were significantly more prone to Theileria ovis infection than bulls. Calf and hybrid yaks were more prone to Anaplasma marginale infection. In conclusion, this is the first report that yaks residing the Gilgit-Baltistan region in Pakistan are infected with Theileria ovis and Anaplasma marginale. Similar larger scales studies are recommended in various regions of Gilgit-Baltistan to document the infection rates of these parasites to formulate strategies that will lead to the effective control of these pathogens.


Assuntos
Anaplasma marginale , Anaplasmose , Theileria , Carrapatos , Feminino , Bovinos , Animais , Ovinos , Anaplasma marginale/genética , Theileria/genética , Paquistão/epidemiologia , Anaplasma/genética , Prevalência , Carrapatos/microbiologia , Carrapatos/parasitologia , Filogenia , Anaplasmose/epidemiologia , Anaplasmose/microbiologia
20.
Zootaxa ; 5410(1): 91-111, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38480255

RESUMO

We describe a new genus Cryptocroton n. gen. for Amblyomma papuanum Hirst, 1914, a tick of North Queensland, Australia, and Papua New Guinea.


Assuntos
Carrapatos , Animais , Queensland , Amblyomma , Papua Nova Guiné , Austrália
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