Molecular detection, risk factors, and phylogenetic analysis of tick-borne pathogens in dogs from northern Vietnam

@#In tropical regions, numerous tick-borne pathogens (TBPs) play a crucial role as causative agents of infectious diseases in humans and animals. Recently, the population of companion and pet dogs has significantly increased in Vietnam; however, information on the occurrence of TBPs is still limited. The objectives of this investigation were to determine the occurrence rate, risk factors, and phylogenetic characteristics of TBPs in dogs from northern Vietnam. Of 341 blood samples tested by PCR, the total infection of TBPs was 73.9% (252/341). Babesia vogeli (18SrRNA gene – 30.5%) was detected most frequently in studied dogs followed by Rickettsia spp. (OmpA gene – 27%), Anaplasma platys (groEL gene – 22%), Bartonella spp. (16SrRNA – 18.8%), Mycoplasma haemocanis (16SrRNA – 9.4%) and Hepatozoon canis (18SrRNA gene – 1.2%), respectively. All samples were negative for Ehrlichia canis and Anaplasma phagocytophylum. Co-infection was detected in 31.4% of the samples (107/341) of which, A. platys/Bartonella spp. (34/94,10%), Rickettsia spp./B. vogeli (19/94, 5.6%), and M. haemocanis/B. vogeli (19/94, 5.6%) were recorded as the three most frequent two species of co-infection types. Statistical analysis revealed a significant correlation between TBP infection and several host variables regarding age, breed, and living area in the current study. The recent findings reported herein, for the first time in Vietnam, are essential for local veterinarians when considering the appropriate approaches for diagnosing these diseases. Furthermore, this data can be used to establish control measures for future surveillance and prevention strategies against canine TBPs in Vietnam.

Molecular biological identification of ticks and tick-borne pathogens in Yadong,Tibet / 中国人兽共患病学报

This study was aimed at identifying species of ticks and investigating infections with tick-borne pathogens a-mong people in Yadong,Tibet.The total of 23 ticks(Ixodes and Haemaphysalis)collected from livestock in Yadong,Tibet in July 2021,the gene sequences of cytochrome oxidase subunitⅠ(COX Ⅰ),mitochondrial 16S ribosomal DNA(16S rDNA)and mitochondrial 12S ribosomal DNA(12S rDNA)were identi-fied on the basis of molecular biology classification.The gene sequences of spotted fever group rickettsia(SFGR),Borrelia burgdorferi,Francisella tularensis and Coxiella burnetii in ticks were amplified by PCR and sequenced,and phylogenetic ana-lyses were performed.In addition,184 serum samples collected from Yadong in 2021 were screened for antibodies to Lyme dis-ease,Q fever,spotted fever,and tularemia by ELISA,and infections with tick-borne pathogens in Yadong were comprehen-sively analyzed.The ticks(Ixodes)collected in Yadong,Tibet,were grouped into two categories.The COX Ⅰ,16S rDNA,and 12S rDNA gene sequences of the ticks had 99.5％,97.57％,and 99.12％ similarity,respectively,to those of Ixodes nuttallia-nus in GenBank.The similarities between the COX Ⅰ and 16S rDNA gene sequences of another Ixodes tick species and the COXⅠ and 16S rDNA gene sequences of Ixodes ovatus in GenBank were 88.29％ and 95.75％,respectively.The similarity between the COX Ⅰ,16S rDNA,and 12S rDNA gene sequences of Haemaphysalis ticks and those of Haemaphysalis Tibet in GenBank were 96.04％,96.17％,and 97.47％,respectively.The sequence amplification results for Borrelia burgdorferi,Francisella tularensis,and Coxsiella burnetii in 23 ticks were negative,whereas gltA gene amplification of spotted fever group Rickettsia in 23 ticks was positive.The similarity of gltA gene sequences with respect to those of Candidatus Rickettsia tarasevichiae,Rickettsia raoultii,Rickettsia canadensis,and a Rickettsia endosymbiont of Eucalyptus brunneri in GenBank was 96.77％,96.76％,95.35％,and 95.35％,respectively.Among 184 serum samples from Yadong,the positivity rates of Lyme disease,Q fever,spotted fever,and tularemia were 6.52％,12.50％,8.70％,and 10.87％,respectively.These results indicated that the 23 parasitic ticks collected in Yadong,Tibet,in July 2021 were Ixodes nuttallianus,Ixodes ovatus and Haemaphysalis ti-betensis,and 23 ticks were infected with SFGR.Lyme disease,Q fever,spotted fever,and tularemia infection were prevalent in the population of Yadong.Therefore,efforts to control tick-borne diseases must be strengthened.

Prevalence of Ehrlichia canis and Hepatozoon canis in sheltered dogs in southern Aburrá Valley, Colombia

Background: Bacteria of the Anaplasmataceae family and canine hemoparasitic protozoans transmitted by ticks are common in Colombia due to circulation and biological adaptation of vector Rhipicephalus sanguineus sensu lato (s.l.). Objective: To detect the circulation of Ehrlichia canis and Hepatozoon canis in sheltered dogs in three municipalities in southern Aburrá Valley, province of Antioquia, Colombia. Methods: Primers were used to amplify the 16S rRNA associated with the Anaplasmataceae family, dsb for Ehrlichia sp. and 18S rRNA for Hepatozoon sp. Results: Of the 357 samples of venous blood obtained, representing all the sheltered dogs in the study zone, Ehrlichia canis DNA was detected in 2.2% of individuals, showing identity of 100% with previous sequences from the GenBank. Hepatozoon canis showed 8.7% (31/357) prevalence of infection, with 100% identity to genotypes from Japan, Brazil, and Spain. Only one sequence of H. canis exhibited a phylogenic divergence concerning H. canis previously reported in Brazil and the Old World. Conclusions: This study confirms the circulation of E. canis and H. canis in asymptomatic shelter dogs in the south-central zone of the Aburrá Valley, province of Antioquia, Colombia. The present study is the first molecular detection of H. canis in the Province of Antioquia and the third report of canine hepatozoonosis from Colombia, highlighting the importance of considering this agent in veterinary clinic.

Antecedentes: Los agentes patógenos transmitidos por garrapatas, tales como las bacterias de la familia Anaplasmataceae y los protozoos hemoparasitarios caninos, son comunes en Colombia debido a la circulación y la adaptación biológica del vector Rhipicephalus sanguineus sensu lato (s.l.). Objetivo: Detectar la circulación de Ehrlichia canis y Hepatozoon canis en perros protegidos en tres municipios del sur del Valle de Aburrá, departamento de Antioquia, Colombia. Métodos: Se usaron cebadores para amplificar el gen 16S rRNA asociado con la familia Anaplasmataceae y el gen dsb para Ehrlichia sp. y el 18S rRNA para Hepatozoon sp. Resultados: De las 357 muestras de sangre venosa obtenidas, que representan a todos los perros de albergues en la zona de estudio, 2,2% fueron positivas para Ehrlichia canis, con 100% de identidad con secuencias anteriores publicadas en todo el mundo. Hepatozoon canis mostró una prevalencia de infección del 8,7% (31/357), con una identidad del 100% con genotipos de Japón, Brasil y España. Solo una secuencia de H. canis exhibió divergencia filogénica en relación con H. canis previamente reportada en Brasil y el Viejo Mundo. Conclusiones: Este estudio confirma la circulación de E. canis y H. canis en perros asintomáticos de albergues en la zona centro-sur del Valle de Aburrá, departamento de Antioquia, Colombia. El presente estudio es la primera detección molecular en el Departamento de Antioquia y el tercer reporte de hepatozoonosis canina de Colombia destacando la importancia de considerar este agente en la clínica veterinaria.

Antecedentes: Agentes patogênicos transmitidos por carrapatos, como bactérias da família Anaplasmataceae e protozoários hemoparasitários caninos, são comuns na Colômbia devido à circulação e adaptação biológica do vetor Rhipicephalus sanguineus sensu lato (s.l.). Objetivo: Detectar Ehrlichia canis e Hepatozoon canis em cães abrigados em três municípios do sul do vale de Aburrá, departamento de Antioquia, Colômbia. Métodos: Os primers foram utilizados para amplificar o rRNA 16S associado à família Anaplasmataceae, o dsb para Ehrlichia sp. e o rRNA 18S para Hepatozoon sp. Resultados: Das 357 amostras de sangue venoso obtidas, representando todos os cães abrigados na zona de estudo, 2,2% foram positivas para Ehrlichia canis, com 100% de identidade com sequências anteriores publicadas em todo o mundo. Hepatozoon canis mostrou uma prevalência de infecção de 8,7% (31/357), com 100% de identidade com genótipos do Japão, Brasil e Espanha. Apenas uma sequência de H. canis apresentou divergência filogênica em relação a H. canis previamente relatados no Brasil e no Velho Mundo. Conclusões: Este estudo confirma a circulação de E. canis e H. canis em cães de abrigo assintomáticos na zona centro-sul do vale de Aburrá, departamento de Antioquia, Colômbia. O presente estudo é a primeira detecção molecular no Departamento de Antioquia e o terceiro relato de hepatozoonose canina na Colômbia, destacando a importância de considerar este agente na clínica veterinária.

Molecular detection of Bartonella, Ehrlichia and Mycoplasma in feral dogs of El Pedregal de San Angel Ecological Reserve in Mexico City / Detecção molecular de Bartonella, Ehrlichia e Mycoplasma em cães selvagens da Reserva Ecológica El Pedregal de San Angel, na Cidade do México

Abstract Free-ranging and feral dogs represent a group of unattended companion animals. They impact wild animal populations by predating native species, displacing predators and introducing exotic pathogens. The aim of this work was to describe the molecular occurrence of Rickettsia, Ehrlichia, Anaplasma, Mycoplasma and Bartonella in feral dogs. The study was carried out in the last relict of a protected area in Mexico City. Blood clots samples from 19 dogs were obtained and analyzed for detection of specific fragments of the 16S-rRNA gene for Anaplasma, Ehrlichia and Mycoplasma and citrate synthase (gltA) for Bartonella and Rickettsia. Our results showed that DNA from three bacteria species (Bartonella vinsonii subsp. berkhoffii, Ehrlichia canis and Mycoplasma haemocanis) was present with frequencies ranging from 5.3 to 15.8%. This is the first record of B. vinsonii subsp. berkhoffii and M. haemocanis in dogs from México, and also the first finding of Ehrlichia canis in Mexico City. It is important to perform surveillance of feral dog populations in order to identify the impact of these pathogens on wild animal populations and Public Health in order to establish prevention and protection programs.

Resumo Cães errantes e selvagens representam um grupo de animais de companhia livres. Eles impactam as populações de animais selvagens pela predação de espécies nativas, deslocando predadores e introduzindo patógenos exóticos. O objetivo deste trabalho foi descrever a ocorrência molecular de Rickettsia, Ehrlichia, Anaplasma, Mycoplasma e Bartonella em cães selvagens. O estudo foi realizado no último ecossistema de uma área protegida na Cidade do México. Amostras de coágulos sanguíneos de 19 cães foram obtidas e analisadas para detecção de fragmentos específicos do gene 16S-rRNA para Anaplasma, Ehrlichia e Mycoplasma e citrato sintase (gltA) para Bartonella e Rickettsia. Nossos resultados mostraram que o DNA de três espécies de bactérias (Bartonella vinsonii subsp. berkhoffii, Ehrlichia canis e Mycoplasma haemocanis) estava presente com frequências variando de 5,3 a 15,8%. Este é o primeiro registro de B. vinsonii subsp. berkhoffii e M. haemocanis em cães do México, e também a primeira descrição de Ehrlichia canis na Cidade do México. É importante realizar a vigilância das populações de cães selvagens para identificar o impacto desses patógenos nas populações de animais silvestres e na Saúde Pública, a fim de estabelecer programas de prevenção e proteção.

Tick-Borne Pathogens in Ixodid Ticks from Poyang Lake Region, Southeastern China

Ticks are the vectors of various pathogens, threatening human health and animal production across the globe. Here, for the first time we detected Ricketssia spp., Borrelia spp. and protozoan in ticks from Poyang Lake region in Jiangxi Province of eastern China. In 3 habitat categories and on 12 host species, 311 ticks from 11 species were collected. Haemaphysalis longicornis was the predominant species, accounting for 55.63%, followed by Rhipicephalus microplus, Haemaphysalis flava and Ixodes granulatus. Of the collected ticks, 7.07% were positive for tick-borne pathogens, and H. longicornis and H. flava were found to be co-infected with Ricketssia spp. and protozoan. H. flava was the most detected positive for tick-borne pathogens, whereas H. longicornis had the lowest infection rate, and the difference in infection rates between tick species was significant (χ²=61.24, P < 0.001). Furthermore, adult ticks demonstrated remarkably greater infection rate than immature ticks (χ²=10.12, P=0.018), meanwhile ticks on Erinaceidae showed significantly higher positivity than ticks collected on other host species (χ²=108.44, P < 0.001). Genetic fragment sequencing and analyses showed at least 4 pathogen species presence in ticks, namely Borrelia yangtzensis, Rickettsia slovaca or Rickettsia raoultii related genospecies, Babesia vogeli and Hepatozoon canis or Hepatozoon felis related genospecies. The finding indicates that the abundant ticks can carry diverse pathogens in Poyang Lake region, and pathogen infection is highly related to species, vertebrate hosts and life stages of ticks.

A serological and molecular survey of Babesia vogeli, Ehrlichia canis and Rickettsia spp. among dogs in the state of Maranhão, northeastern Brazil / Detecção sorológica e molecular de Babesia vogeli, Ehrlichia canis e Rickettsia spp. em cães do Estado do Maranhão, Nordeste do Brasil

This study evaluated exposure and infection by tick-borne agents (Babesia vogeli, Ehrlichia canis and Rickettsia spp.) in 172 dogs in rural areas and 150 dogs in urban areas of the municipality of Chapadinha, state of Maranhão, northeastern Brazil, using molecular and serological methods. Overall, 16.1% of the sampled dogs (52/322) were seroreactive to B. vogeli, with endpoint titers ranging from 40 to 640. For E. canis, 14.6% of the dogs (47/322) were seroreactive, with endpoint titers from 80 to 163,840. Antibodies reactive to at least one of the five species of Rickettsia were detected in 18.9% of the dogs (61/322), with endpoint titers ranging from 64 to 4,096. High endpoint titers were observed for Rickettsia amblyommii. Three (0.9%) and nine (2.8%) canine blood samples were PCR-positive for Babesia spp. and E. canis. The ticks collected from urban dogs were all Rhipicephalus sanguineus sensu lato, whereas the rural dogs were infested by R. sanguineus s.l, Amblyomma cajennense sensu lato and Amblyomma ovale. One A. ovale tick was found to be infected by Rickettsia bellii. This study provides an epidemiological background for controlling and preventing canine tick-borne diseases in a neglected region of Brazil.

Este estudo avaliou por métodos sorológicos e moleculares a exposição e infecção por agentes transmitidos por carrapatos (Babesia vogeli, Ehrlichia canis, and Rickettsia spp.) em 172 cães de áreas rurais e 150 cães de áreas urbanas do município de Chapadinha, Estado do Maranhão, Nordeste do Brasil. No geral, 16,1% dos cães amostrados (52/322) apresentaram soros reagentes para B. vogeli, com títulos finais variando de 40 a 640. Para E. canis, 14,6% cães (47/322) apresentaram soros reagentes com títulos finais de 80 a 163,840. Anticorpos reativos para pelo menos uma das cinco espécies de Rickettsia foram detectados em 18,9% dos cães (61/322), com os títulos que variam de 64 a 4096. Foram observados altos títulos para Rickettsia amblyommii. Três amostras de sangue canino (0,9%) e 9 (2,8%) foram PCR positivas para Babesia spp e E. canis. Os carrapatos coletados de cães urbanos eram todos Rhipicephalus sanguineus sensulato, e os cães rurais estavam infestados por R. sanguineus s.l , Amblyomma cajennense sensu lato e Amblyomma ovale. Um carrapato A. ovale foi encontrado infectado por Rickettsia bellii. Este estudo fornece um conhecimento epidemiológico para o controle e prevenção de doenças transmitidas por carrapatos de cães em uma região negligenciada do Brasil.

Genetic Identification and Phylogenetic Analysis of Anaplasma and Ehrlichia Species in Haemaphysalis longicornis Collected from Jeju Island, Korea

A total of 1,395 Haemaphysalis longicornis ticks collected from Jeju Island of Korea were examined by 16S rRNA gene-based nested PCR for the presence of infection with Anaplasma and Ehrlichia species. Template DNAs to detect the tick-borne pathogens were prepared from a total 506 tick pools. Eight genera of Anaplasma and six Ehrlichia by 16S rRNA gene PCR and sequencing analysis were identified. A. phagocytophilum was the most prevalent (27 [1.9%]) by nested PCR, followed by A. bovis (5 [0.4%]), E. chaffeensis (4 [0.2%]), and A. centrale (1 [0.1%]). In the phylogenetic analysis based on 16S rRNA sequences, eight genera of Anaplasma group (> 99.4% homology) and six Ehrlichia group (> 99.5% homology) were close to deposited A. marginale strains (AF309867, AF414874, and FJ226454) and Ehrlichia sp. (DQ324547), respectively. Three Anaplasma species groups A. phagocytophilum (group A), A. bovis (group B), and A. centrale (group C) and one Ehrlichia species E. chaffeensis (group D) were determined by comparing with Anaplasma and Ehrlichia related sequences. First, twenty-eight A. phagocytophilum clones belonging to group A were divided into 7 genotypes. The sequence similarity among genotypes A1 to A4 was very high (> 99.6%). Genotype B2 was close to A. bovis from Korea (99.7%). Genotype D1 was close to known E. chaffeensis strains (M73222, AF147752, and AY350424) and their similarity value was 99.7%. In conclusion, the genera of Anaplasma/Ehrlichia, A. phagocytophilum, and E. chaffeensis identified in predominant H. longicornis ticks were ubiquitous throughout the Jeju Island. The various native groups have been found through sequence identities and phylogenetic analysis.

Microbial pathogens in ticks, rodents and a shrew in northern Gyeonggi-do near the DMZ, Korea

A total of 1,618 ticks [420 individual (adults) and pooled (larvae and nymphs) samples], 369 rodents (Apodemus arius, Rattus norvegicus, Tscherskia triton, Mus musculus, and Myodes regulus), and 34 shrews (Crocidura lasiura) that were collected in northern Gyeonggi-do near the Demilitarized Zone (DMZ) of Korea during 2004-2005, were assayed by PCR for selected zoonotic pathogens. From a total of 420 individual and pooled tick DNA samples, Anaplasma (A.) phagocytophilum (16), A. platys (16), Ehrlichia (E.) chaffeensis (63), Borrelia burgdorferi (16), and Rickettsia spp. (198) were detected using species-specific PCR assays. Out of 403 spleens from rodents and shrews, A. phagocytophilum (20), A. platys (34), E. chaffeensis (127), and Bartonella spp. (24) were detected with species-specific PCR assays. These results suggest that fevers of unknown causes in humans and animals in Korea should be evaluated for infections by these vector-borne microbial pathogens.