Prevalence of Ehrlichia-, Babesia-, and Hepatozoon-infected brown dog ticks in Khon Kaen Province, Northeast Thailand

TRP36-ELISA for E. canis detection: Concordance with TaqMan real-time PCR and point-of-care testing

Ehrlichia canis, a widely distributed tick-borne pathogen, requires prompt and accurate diagnosis for effective management. Real-time PCR serves as the reference standard for diagnosing E. canis infection, whereas serological tests are crucial for detecting antibody responses indicative of infection or post-exposure status. Early detection during the acute phase of the disease is essential for optimal treatment and recovery. E. canis Tandem Repeat Protein 36 (TRP36) elicits early acute phase responses. We developed an enzyme-linked immunosorbent assay (ELISA) using recombinant TRP36 to detect IgM and IgG antibodies against E. canis. We assessed the diagnostic agreement, sensitivity, and specificity of the rTRP36-ELISA and a commercial test kit (SNAP 4Dx Plus Test) with TaqMan Real-time PCR (qPCR) using the NCSS 2023 program version 23.0.1. Leftover serum samples from 32 dogs at the Veterinary Teaching Hospital were randomly selected and examined for E. canis infection using qPCR, rTRP36-ELISA, and SNAP 4Dx Plus Test. qPCR detected positive results in 12 (37.5 %), whereas ELISA and SNAP 4Dx Plus detected positive results in 10 (31.25 %) and 13 (40.62 %), respectively. Moderate agreement (κ = 0.545) was observed between rTRP36-ELISA and qPCR, and fair agreement (κ = 0.379) between SNAP 4Dx Plus and qPCR. Substantial agreement (κ = 0.79) was found between rTRP36-ELISA and SNAP 4Dx Plus. Compared to qPCR, the sensitivity and specificity of rTRP36-ELISA were 70 % and 77.27 %, respectively, compared to 53.85 % and 73.86 %, respectively, for SNAP 4Dx Plus. Our findings suggest that TRP36 is a promising antigen for E. canis serodiagnosis, potentially improving sensitivity and specificity.

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.

Bacteria in the blood of healthy stray dogs infested by ticks in northern Mexico

Objective

The objectives of this study were to determine the richness, abundance, and diversity of bacteria in stray dogs (Canis lupus familiaris) infested by ticks in Comarca Lagunera, northern Mexico, and to establish their pathogenic and or/zoonotic potential.

Materials and Methods

Blood samples from 12 dogs were collected, and their deoxyribonucleic acid was extracted. The V3-V4 region of the 16S ribosomal ribunocleic acid gene was amplified by polymerase chain reaction. Next-generation sequencing (NGS) was performed on a MiSeq Illumina platform, and the data were analyzed using quantitative insights into microbial ecology.

Results

The operational taxonomic units resulted in 23 phyla, 54 classes, 89 orders, 189 families, 586 genera, and 620 bacterial species; among them, 64 species and/or bacterial genera with pathogenic or zoonotic potential were identified, some of which have been reported in the literature as relevant to public health (Anaplasma phagocytophilum, Brucella spp., Clostridium spp., Corynebacterium affermentants, Cutibacterium spp., Dietzia spp., Ehrlichia canis, Fusobacterium necrophorum, Leptotrichia spp., Mycobacterium spp., Paracoccus spp., and Roseomonas gilardii).

Conclusion

This research offers relevant information on the prevalence of tick-borne diseases as well as other potential zoonotic diseases in the blood of stray dogs parasitized by ticks in northern Mexico. New molecular biology and massive NGS techniques may play an important role in the study and documentation of bacterial profiles from animals in close proximity to humans.