Tick-borne pathogens Ehrlichia, Hepatozoon, and Babesia co-infection in owned dogs in Central Thailand.

Tick-borne pathogens are transmitted by a wide range of tick species and affect both human and animal health. Understanding the diversity of these pathogens and their co-infection rates in domesticated animals in urban areas is crucial for effective disease management and prevention. In this study, a total of 565 owned dogs in the central region of Thailand were investigated for the infection rate of three genera of Ehrlichia, Hepatozoon, and Babesia infection using multiplex PCR. The results revealed an overall infection rate of 19.1%, with Ehrlichia having the highest infection rate (12.2%), followed by Babesia (2.5%) and Hepatozoon (1.4%). The rate of co-infection was 3%, with mixed infections involving two or three genera. Male dogs exhibited a slightly higher infection rate compared to females, although not statistically significant. Young adult dogs (1-3 years) showed the highest infection rate of both single infections and co-infections. Monthly infection rate indicated variations throughout the year, with co-infection rate significantly associated with overall infection rate. Clinical manifestations in three genera of infected dogs included thrombocytopenia and eosinopenia. The results of this study are useful to design strategies for the management and prevention of tick-borne diseases in the study area.

Diversity and genetic characterization of Chlamydia isolated from Siamese crocodiles (Crocodylus siamensis).

Chlamydiosis, an infection caused by several Chlamydia species, has been reported in Nile, saltwater, and Siamese crocodiles. Despite its widespread reports in various countries, including Thailand, genetic information on Chlamydia species remains limited. This study presents a whole-genome-based characterization of Siamese crocodile-isolated Chlamydia. The results showed that Siamese crocodile Chlamydia contained a single circular chromosome with a size of 1.22-1.23 Mbp and a plasmid with a size of 7.7-8.0 kbp. A plasmid containing eight coding sequences (CDSs) was grouped in a ß lineage. A chromosome sequence had approximately 1,018-1,031 CDSs. Chlamydial factors involving virulence were documented in terms of the presence of cytotoxins and several virulence factors in the chromosomes of Siamese crocodile Chlamydia. The analysis of antimicrobial resistance genes in the Chlamydia genome revealed that the most common resistance genes were associated with aminoglycosides, fluoroquinolones, macrolides, tetracyclines, and cephalosporins, with loose matching (identities between 21.12 % and 74.65 %). Phylogenetic analyses, encompassing the assessments of both whole proteome and nine taxonomic markers, revealed that Siamese crocodile Chlamydia was separated into three lineages (lineages I-III) with high bootstrapping statistic support. Interestingly, isolate 12-01 differed genetically from the others, suggesting that it is a new member of Chlamydia. The study findings indicate that Siamese crocodiles are susceptible hosts to Chlamydia, involving more than one species. This study is the first employing the highest number of whole-genome data on Siamese crocodile Chlamydia and provides better insights into pathogen genetics.

Occurrence of Chlamydia spp. In wild birds in Thailand

Objective: To determine the occurrence of Chlamydia spp. in wild birds in Thailand. Methods: Cloacal and tracheal swabs of 313 wild birds from 11 orders, 27 families, and 51 species were tested to determine the occurrence of Chlamydia infection. The outer membrane protein A (ompA) gene was amplified from positive samples to construct a phylogenetic tree. Results: At the time of sample collection, none of the birds showed clinical signs of any disease. Of 313 wild birds, two Asian openbill stork (Anastomus oscitans) were positive for Chlamydia spp., representing 0.64% (2/313) and 4.9% (2/41) occurrence for birds overall and for the Asian openbill stork, respectively. Phylogram analysis based on deduced amino acid of the ompA gene showed that Chlamydia spp. in Asian openbill storks was closely related to that in wildfowl (Pica pica and Cygnus olor) from Poland in a different branch with a 95% bootstrap value and had a shorter evolutionary distance to Chlamydia abortus. Conclusions: Asymptomatic Asian openbill storks could be a potential source of Chlamydia infection in domestic animals, poultry, and humans who share their habitat.