Tick-borne Pathogen Detection and Its Association with Alterations in Packed Cell Volume of Dairy Cattle in Thailand.

Tick-borne diseases (TBDs) massively impact bovine production. In endemic countries, animals are often subclinically infected, showing no signs of the illness. Anemia is a hallmark of TBDs, but there is inadequate information on its presence in infected Thai cattle. In the present study, 265 cattle from four provinces in Thailand were surveyed to identify tick-borne pathogens (TBPs) and to evaluate the changes in the packed cell volume (PCV) values associated with detection. Microscopy and polymerase chain reaction (PCR) were also compared for TBP detection. Babesia/Theileria/Hepatozoon was detected in 33.58% (89/265) of the cattle samples. Specifically, Babesia bovis (9/265), B. bigemina (12/265), Theileria orientalis (62/265), and Anaplasma marginale (50/265) were identified using species-specific assays. Significant decreases in the mean PCV levels were observed in cattle that were positive for at least one TBP (p < 0.001), Babesia/Theileria/Hepatozoon (p < 0.001), T. orientalis (p < 0.001), and A. marginale (p = 0.049). The results of PCR and microscopy for the detection of TBPs suggested slight and fair agreement between the two detection tools. The present findings contribute to a better understanding of TBDs in the field and shall facilitate the formulation of effective control for TBDs in Thailand.

Histopathology and virulence of an in vitro-adapted Trypanosoma evansi TEDC 953 strain (Thailand isolate) in mice.

Background and Aim: Trypanosoma evansi is a blood and tissue protozoan parasite affecting domestic and wild animals. The T. evansi Thai strain, namely, T. evansi from dairy cattle number 953 (TEDC 953) strain, has been successfully isolated from dairy cattle and cultivated in vitro. The in vitro-cultivated parasite is useful for biological studies, evaluation of novel chemotherapeutic agents, and production of antigens for diagnostic tests. This study aimed to observe the histopathology and virulence of an in vitro-adapted T. evansi TEDC 953 strain in vivo. Materials and Methods: The histopathology and virulence of the TEDC 953 strain were clarified in mice. Six mice were infected with 1 × 105 trypomastigotes of TEDC 953 strain intraperitoneally, and four mice were in the negative control. Parasitemia was monitored daily, and the mice were euthanized on 30 days post-infection (DPI). Internal organs were collected for histopathological examination using hematoxylin and eosin staining. Results: Histopathological lesions were found in the liver, lung, heart, kidney, spleen, and brain of the inoculated mice. The main histopathological feature was lymphoplasmacytic inflammation in parenchyma and perivascular areas of multiple organs, and the severity of histopathological changes was related to the presence of trypomastigotes in the regional vessels. Granulomatous inflammation was seen in meninges, pleura, renal capsule, renal pelvis, and spleen of some infected mice. Four mice died at 17, 24, 26, and 27 DPI with an average parasitemia of 4.05 × 1011 trypomastigotes/mL. The average survival time was 23.5 DPI (mice = 4). Conclusion: This study confirmed that the TEDC 953 strain is infectious and pathogenic in mice after the continuously cultivated in vitro. To replace the use of experimental animals, the in vitro-cultivated parasite can be used instead in further studies.

Molecular Identification of Culicoides Species and Host Preference Blood Meal in the African Horse Sickness Outbreak-Affected Area in Hua Hin District, Prachuap Khiri Khan Province, Thailand.

African horse sickness (AHS) was reported as an outbreak in Thailand in 2020. Hematophagous insects from the genus Culicoides are the suspected vector responsible for AHS transmission. Horses in Hua Hin district, Prachuab Khiri Khan province, Thailand, were affected and died from AHS in 2020. However, the potential Culicoides species and its host preference blood meal in the affected areas are unknown. To investigate the potential vectors of AHS, Culicoides were collected using ultraviolet light traps placed near horse stables. Six horse farms, including five farms with AHS history and one farm without AHS history, were included in this study. Morphological and molecular identification of the Culicoides species was performed. Polymerase chain reaction (PCR) targeting the cytochrome b oxidase I (COXI) gene for confirmation of the Culicoides species, identification of the prepronociceptin (PNOC) gene for host preference blood meal, and bidirectional sequencing were conducted. Consequently, 1008 female Culicoides were collected, consisting of 708 and 300 samples captured at positions A and B at a distance of <2 and >5 m from the horse, respectively. Twelve Culicoides species identified by morphology were noted, including C. oxystoma (71.92%), C. imicola (20.44%), C. actoni (2.28%), C. flavipunctatus (1.98%), C. asiana (0.99%), C. peregrinus (0.60%), C. huffi (0.60%), C. brevitarsis (0.40%), C. innoxius (0.30%), C. histrio (0.30%), C. minimus (0.10%), and C. geminus (0.10%). The PCR detection of the Culicoides COXI gene confirmed Culicoides species in 23 DNA samples. PCR targeting the PNOC gene revealed that the Culicoides collected in this study fed on Equus caballus (86.25%), Canis lupus familiaris (6.25%), Sus scrofa (3.75%), and Homo sapiens (3.75%) for their blood meal. Human blood was identified from two samples of C. oxystoma and a sample of C. imicola. Three dominant species including C. oxystoma, C. imicola, and C. actoni that were reported in the Hua Hin area prefer to feed on horse blood. Moreover, C. oxystoma, C. imicola, and C. bravatarsis also feed on canine blood. This study revealed the species of Culicoides in Hua Hin district, Thailand, after the AHS outbreak.

Companion Vector-Borne Pathogens and Associated Risk Factors in Apparently Healthy Pet Animals (Dogs and Cats) in Khukhot City Municipality, Pathum Thani Province, Thailand.

Pet animals (dogs and cats) can be infected with several companion vector-borne pathogens (CVBPs). Morbidity and mortality have been reported in pet animals due to CVBP infections. Pet animals living in close proximity to humans are able to transmit zoonotic pathogens. This study used molecular techniques to investigate the prevalence of CVBPs in apparently healthy pet animals (dogs and cats) from Khukhot City Municipality, Pathum Thani province, Thailand. In total, 210 blood samples were randomly collected from 95 dogs and 115 cats for the detection of seven companion vector-borne pathogens (Anaplasma, Babesia, Bartonella, Ehrlichia, Hepatozoon, Mycoplasma, and Rickettsia) using polymerase chain reaction. The results showed that 10.5% (22/210) of apparently healthy pet animals were infected with at least one pathogen, comprising 6 dogs (6.3% of all dogs tested) and 16 cats (13.9% of all cats tested). Ehrlichia (6.3%) was present only in dogs; furthermore, 1.1% of the dogs were positive for Anaplasma. There was one dog case co-infected with two pathogens (1.1%). In cats, Mycoplasma (9.6%) was the predominant CVBP, followed by Rickettsia (4.4%). The DNA sequences of all positive animals were 97-99% homologous to those found in the GenBank™ database for all CVBPs identified, namely Ehrlichia canis, Anaplasma platys, Rickettsia felis, Mycoplasma haemofelis, and Candidatus Mycoplasma haemominutum. Additionally, the risk of infection with CVBPs in pets was significantly associated with age, with young dogs more likely to be infected with CVBPs than adult dogs (OR 8.5, 95% CI 1.4-50.1, p = 0.006), while adult cats were more likely to be infected with CVBPs than young cats (OR 3.8, 95% CI 1.0-14.0, p = 0.038). The detection of CVBPs demonstrated the potential risk of infection that may occur in apparently healthy pet animals in Pathum Thani province. These results confirmed that apparently healthy pet animals may still be at risk of vector-borne infections and could maintain the infection cycle in pet populations. Furthermore, sampling a greater number of apparently healthy pet animals may disclose predictors of CVBP positivity in domesticated animals in this area.

Serological Detection of Toxoplasma gondii among Free-Grazing Ducks from Central and Western Thailand-A One Health Perspective on Integrated Farming.

Toxoplasmosis is one of the most common zoonotic parasitic diseases infecting nearly all warm-blooded animals, including poultry (geese, turkeys, chickens, and ducks). It is caused by Toxoplasma gondii (T. gondii), which is an obligate intracellular protozoan belonging to the Apicomplexa group. In Thailand, duck meat production for domestic consumption and international trade is mainly bred and produced in the central and western parts of the country. Free-grazing ducks in integrated duck-rice production have significant benefits in rice cultivation, accounting for the popularity of this farming system in Thailand. However, ducks are considered particularly susceptible to consuming T. gondii oocysts from water contaminated with cat feces due to the fact of their feeding habits of free-grazing and dabbling. Hence, the prevalence of this zoonotic parasite in a large-scale integrated farming context is particularly challenging with respect to the contamination of the food chain of humans and farm animals. In the present study, we examined the overall prevalence of T. gondii infection in slaughtered free-grazing ducks originating from Central and Western Thailand, setting the stage for an in-depth One Health approach to assess and manage the risks of integrated farming practices. A representative sample size of 161 ducks was calculated using a two-stage sampling method. Specifically, serum samples were collected from 217 slaughtered free-grazing ducks originating in six provinces in Central and Western Thailand. Serum antibodies against T. gondii were detected using an indirect fluorescent antibody test (IFAT). The positive control serum samples were prepared from ducks experimentally immunized with T. gondii. Sixty-eight (31.3%) of the two hundred and seventeen ducks were seropositive with T. gondii. Two groups of fattening ducks and spent layers showed similar seropositivity rates at 29% and 32.3%, with the majority of positive samples being found in the low titer. In addition, a wide distribution of positive serum samples was observed in all six provinces in the present study. To the best of our knowledge, this is the first report on a serological prevalence snapshot in commercially produced duck populations that have high interaction with farmed environments in Thailand, revealing a high infection pressure in areas of integrated duck-rice farming. Importantly, contaminated duck meat for commercial use, as well as offal and carcasses from slaughterhouses, completes the transmission of T. gondii from the environment into the food chain of humans and domestic animals. Hence, from a One Health perspective, it is important to clarify whether this transmission chain extends further to the wild, i.e., predator-prey cycles that are independent of duck farming or are self-contained.

Molecular Detection and Genetic Characterization of Zoonotic Hookworm in Semi-Domesticated Cats Residing in Monasteries in Bangkok, Thailand.

Hookworms are the most common parasitic nematodes in the genus of Ancylostoma that infect both humans and animals in subtropical and tropical South East Asia. The common hookworm species in cats is Ancylostoma ceylanicum which is emerging in Thailand. However, the genetic characterization of hookworms in cats is outdated and insufficiently studied in Thailand. We aimed to investigate the prevalence, risk factors and genetic characterization of hookworm infection in semi-domesticated temple cats in Bangkok, Thailand. A total of 500 temple cat fecal samples were collected from 43 monasteries in 24 districts of Bangkok, Thailand. Polymerase Chain Reaction (PCR) was performed by amplifying the internal transcribed spacer (ITS) gene and mitochondrial cytochrome oxidase c subunit I (cox 1) gene. The infection prevalence of hookworm in temple cats was 13.2% (66/500). The highest prevalence was 34.6% in the Bang Khun Thian district, which is located in a suburban area. The risk factor analysis revealed that cats older than one year (OR 2.4, 95% CI 1.1-5.5, p < 0.05), lack of veterinary attention (OR 2.9, 95% CI 1.7-4.9, p < 0.001) and Bangkok zone (suburban vs. inner city; OR 2.9, 95% CI 1.6-5.4, p < 0.001) were significantly increasing hookworm infection risk. All hookworm positive samples were identified as A. ceylanicum by ITS gene. Moreover, genetic characterization of cox 1 gene in A. ceylanicum isolates indicated a mix of isolates from humans, cats and dogs. The findings show that temple cats can act as a potential source of zoonotic hookworm parasites for the human and animal population in Bangkok, Thailand. Therefore, appropriate control measures for hookworms in semi-domesticated temple cats as well as prevention measures for hookworms in pet cats and humans should be promoted.

A Flow Cytometry Study of the Binding and Stimulation Potential of Inactivated Trypanosoma evansi toward Dromedary Camel Leukocytes.

Surra, a wasting disease caused by Trypanosoma evansi, is one of the major animal health burdens in camel-rearing countries, imposing significant economic losses due to reduced fertility and high mortality rates. The present study used inactivated T. evansi (from the Card Agglutination Test for Trypanosomes/Trypanosoma evansi; CATT/T. evansi) and flow cytometry to investigate their binding and activation potential toward camel leukocyte subsets. Labeling T. evansi with propidium iodide (PI) enabled their flow cytometric enumeration and identification with forward scatter (FSC; indicative for cell size) and side scatter (SSC; indicative for cell internal complexity) characteristics that are comparable with values reported for Trypanosoma cruzi. The incubation of PI-labeled non-opsonized T. evansi with camel leukocyte populations revealed that camel monocytes have the highest potential to bind T. evansi, followed by granulocytes and lymphocytes. The identification of pattern recognition receptors (PRRs) on camel immune cells and the pathogen-associated molecular patterns (PAMPs) in T. evansi that are responsible for this different binding capacity requires further studies. Stimulation of camel neutrophils with Trypanosoma evansi induced shape change, reactive oxygen species (ROS) production, and neutrophil extracellular traps (NET)-formation. To ensure that T. evansi, in the parasite concentration used in this study, is not apoptotic or necrotic to camel leukocytes, we evaluated cell apoptosis and necrosis after stimulation with T. evansi. The results revealed no impact of T. evansi stimulation for 2 h on the cell viability of camel leukocytes. Subsequent work may focus on the diagnostic employment of labeled T. evansi and flow cytometry for the detection of anti-Trypanosoma antibodies in camel serum. In addition, more efforts should be deployed to investigate the host-pathogen interaction mechanisms and the escape mechanisms of T. evansi in camels. To complete these data, further studies using the living or freshly killed parasites could also be implemented in camels and/or horses.

Detection of Giardia duodenalis Zoonotic Assemblages AI and BIV in Pet Prairie Dogs (Cynomys ludovicanus) in Bangkok, Thailand.

Giardia is a flagellate protozoa that can be transmitted via direct contact and by consuming contaminated water. It is pathogenic in humans and various other animals, including exotic pets. Pet prairie dogs are popular in Thailand, but they have not been investigated regarding giardiasis. Giardia infection was measured, and genetic characterization was performed to investigate the zoonotic potential of Giardia carried by pet prairie dogs. In total, 79 fecal samples were examined from prairie dogs visiting the Kasetsart University Veterinary Teaching Hospital during 2017-2021. Simple floatation was conducted. Two Giardia-positive samples were submitted for DNA extraction, PCR targeting the Giardiassu rRNA, tpi and gdh genes was performed, and genetic characterization using sequencing analysis was conducted. Risk factors associated with Giardia infection were analyzed. Giardia infection was found in 11 out of the 79 pet prairie dogs (13.9%). Giardia infection was significantly higher in male prairie dogs (p = 0.0345). Coccidia cysts (12.7%), the eggs of nematodes (6.3%), and amoeba cysts (2.5%) were also detected. Genetic characterization of the two Giardia-positive samples revealed that they were G. duodenalis assemblage A, sub-genotypes AI and assemblage B, and sub-genotype BIV, the zoonotic assemblages. This was the first report of Giardia infection in pet prairie dogs in Bangkok, Thailand. The results revealed that these pet prairie dogs in Thailand were infected with zoonotic assemblages of G. duodenalis sub-genotype AI, which might have been derived from animal contaminants, whereas sub-genotype BIV might have been derived from human contaminants. Owners of prairie dogs might be at risk of giardiasis or be the source of infection to their exotic pets.

Preliminary Study on Comparative Efficacy of Four Light Sources for Trapping Culicoides spp. (Diptera: Ceratopogonidae) in Prachuap Khiri Khan Province, Thailand.

The light trap is an important tool to determine the presence and abundance of vectors in the field. However, no one has studied the efficiency of light traps for collecting Culicoides in Thailand. In the present study, the efficacy of four light sources was evaluated in Prachuap Khiri Khan province, Thailand. Incandescent (INCND) light, white fluorescent (WHT-FLR) light, ultraviolet fluorescent (UV-FLR) light, and UV light-emitting diode (UV-LED) light were tested using commercial traps. In total, 30,866 individuals of Culicoides species were collected from November 2020 to June 2021, of which 21,016 were trapped on site 1 and 6,731 were trapped on site 2. The two most abundant Culicoides species were C. imicola (54%) and C. oxystoma (31.2%). UV-FLR was highly effective, followed by UV-LED light, WHT-FLR light, and INCND light, respectively, for Culicoides collection. Significantly, more Culicoides species were collected in those traps baited with UV-FLR light, UV-LED light, or WHT-FLR light than for INCND light traps. Traps equipped with UV-FLR lights can be recommended to trap Culcoides biting midges for monitoring purposes.

Isolation and in vitro cultivation of Trypanosoma evansi Thai strains.

Trypanosoma evansi is a flagellate protozoan parasite responsible for "surra". To generate T. evansi antigens for serodiagnosis, parasites are generally propagated in laboratory animals before isolation. The alternation of animal models using axenic cultivation systems to produce trypomastigotes of various Trypanosoma species is currently available but has never been applied in Thailand. The isolation protocol for separation of live T. evansi trypomastigotes from animal blood components before in vitro cultivation has not been clearly documented. This study focused on validation of trypomastigote isolation method, in vitro cultivation of T. evansi Thai strains, and its virulence ability in vivo. In this study, two strains of T. evansi collected from Thailand were used. Trypanosoma evansi trypomastigotes were propagated in mice, and three different isolation methods, including: low-speed centrifugation, high-speed centrifugation, and ion exchange chromatography using diethylaminoethyl (DEAE) cellulose (or DE52), were compared. Four solutions of in vitro cultivation media, two different in vitro cultivation containers, and different trypomastigote densities for initiation of in vitro culture were compared. Virulence test using in vitro-adapted parasite for 100 days was conducted in vivo. The results showed that the DE52 isolation method was suitable for separation of live T. evansi trypomastigotes from animal blood components before conducting in vitro cultivation. Trypanosoma evansi Thai strains were successfully cultivated and multiplied in HMI-9 Solution I using 25 cm2 flasks and 12-well plates. The parasite was growing slowly at the initiation of in vitro culture for 15-16 days, and then rapidly increased to 10, 20, 50, 100, and 200 folds, approximately. The doubling times were varied from 11.95 ± 8 h to 41.18 ± 4.29 h in vitro. The maximum densities have reached from 0.14 × 106 to 4.63 × 106 trypomastigotes/ml. Virulence test showed that the in vitro-cultivated T. evansi was virulent in mice. In conclusion, T. evansi Thai strains were successfully isolated and cultivated in vitro for the first time. The isolation and in vitro cultivation protocols were clearly provided. The benefit of using the in vitro cultivation system helps in the production of T. evansi antigen, and replacing the use of experimental animals. It is also useful for the development of diagnostic tests in the future.

Viability of Toxoplasma gondii tachyzoites in different conditions for parasite transportation.

Background and Aim: Toxoplasma gondii tachyzoite is the infective stage that causes acute infection, leading to severe toxoplasmosis. The tachyzoite stage has been extensively used for several inoculation purposes, including antigen production, immunological studies, nutrition mechanisms, and in vitro drug trials. The use of fresh tachyzoites is required for inoculation in either in vitro or in vivo studies. However, there is a lack of information on preserving live tachyzoites during transportation from laboratories to inoculation sites. Therefore, this study aimed to validate suitable preservative conditions for maintaining live parasites by determining the survival and viability of T. gondii tachyzoites on the basis of different media, temperatures, and incubation times. Materials and Methods: The free live T. gondii tachyzoites were evaluated on their viability when maintained in different media without 5% Carbon dioxide (CO2). The purified tachyzoites of the RH and PLK strains were individually suspended in normal saline (NS), phosphate-buffered saline (PBS), minimum essential medium (MEM), and MEM with 10% fetal bovine serum (MEM-FBS) and incubated for 6 h at ice-cold (IC; 3-9°C) and room temperature (RT; 25°C). Parasite survival was measured at the 0, 1st, 2nd, 3rd, 4th, 5th, and 6th h post-incubation using the trypan blue exclusion test. Results: The viability was in the range of 85.0%-91.0% for IC using NS and 81.0%-85.1% (IC) and 75.3%-77.5% (RT) using PBS. The viability was approximately 75.0%-83.0% (IC) and 70.0%-79.0% (RT) using MEM and MEM-FBS. There was a significant difference in the viability between the seven periods on the basis of one-way repeated Analysis of variance and Friedman analyses. Parasite survival slightly reduced (20.0%-30.0%) in NS and MEM-FBS at both temperatures during incubation. Notably, PBS could not support tachyzoite viability after 3 h post-incubation. Conclusion: NS was a suitable preservative for maintaining purified T. gondii tachyzoites during transportation at IC and RT without 5% CO2 supplementation. This could be a valuable medium for parasite transportation, especially when there is a large distance between the laboratory and inoculation site.

Theileria infection in bullfighting cattle in Thailand.

Background and Aim: An apicomplexan protozoan parasite, namely, Theileria, primarily causes theileriosis in cattle worldwide. The virulence of the disease has been neglected because of it's low pathogenicity. However, the disease can have a substantial effect, depending on the virulence of the species, low host immunity, and coinfection. In Thailand, the molecular detection of Theileria infection in bullfighting cattle and its hematological alterations have not been reported. Thus, this study aimed to identify Theileria species in bullfighting cattle in Thailand. Materials and Methods: Blood samples were collected from bullfighting cattle presented at the Prince of Songkla University Animal Hospital and were determined on the basis of hematological evaluation and DNA extraction. Molecular detection using the 18s rRNA and merozoite surface antigen genes was conducted for Theileria spp. and Theileria orientalis, respectively. In addition, bidirectional sequencing of the positive samples was performed. Hematological alterations between Theileria infected and uninfected groups were statistically evaluated. Results: The levels of Theileria spp. and T. orientalis infection in bullfighting cattle were 44.62% (58/130) and 41.54% (54/130), respectively. Theileria orientalis, Theileria sinensis, and Theileria spp. infections were identified in bullfighting cattle samples. Hematological evaluation indicated that the red blood cell (RBC) level was significantly lower in Theileria-infected cattle. Conclusion: This study was the first to use molecular techniques in the identification of Theileria infection in bullfighting cattle in Thailand, with nearly one-half of the study population infected. Theileria infection in bullfighting cattle altered the RBC level, resulting in anemia. Therefore, tick control measures should be promoted.

Knowledge, attitude, and practices associated with rabies in villages with different dog vaccination statuses in Cambodia.

BACKGROUND AND AIM: Rabies is a highly infectious but neglected zoonotic disease. Almost 99% of rabies-related human deaths are caused by dog-mediated rabies. Although canine rabies vaccination is highly effective and provides protection, nationwide rabies vaccination campaigns have been insufficient in Cambodia, resulting in a limited number of rabies vaccinated dogs. This study aimed to explore the rabies knowledge, attitude, and practices (KAP) among participants from both dog rabies vaccinated (DRV) and dog rabies unvaccinated (DRUV) villages located in the Kandal and Prey Veng Provinces, Cambodia. MATERIALS AND METHODS: A cross-sectional survey was conducted with dog owners in Kandal and Prey Veng Provinces, Cambodia, during August and September 2020. The structural questionnaire collected general sociodemographic information and the KAP associated with rabies transmission, clinical signs, management, and control. The data were then analyzed using Wilcoxon rank-sum test and Chi-square statistics. RESULTS: In total, 312 participants were interviewed: 137 participants from DRV villages and 175 from DRUV villages. Among them, 99.4% (310/312) had previously heard about rabies. Out of these 310, 93.5% (290/310) were aware that rabies is a fatal disease, while 96.5% (299/310) were willing to vaccinate their dog against rabies if the vaccination was provided for free. However, 32.9% (102/310) indicated that they would be willing to sell their own dog if it bit someone or showed aggression. More than one-third (115/310) of all the respondents had poor overall KAP regarding rabies. The respondents from DRV villages had significantly higher overall scores with regard to rabies KAP than those from DRUV villages (p<0.0001). According to the factors related to overall KAP, village type and education level were significantly associated with overall KAP of the respondents (p<0.0001). CONCLUSION: The rabies disease is recognized in Cambodia, and dog owners are willing to vaccinate their dogs if the vaccination is provided for free. The overall rabies-related KAP were poor among 30% of the respondents, and higher KAP scores were obtained for the DRV villages. The village type and education level were found to be associated with the different overall KAP of the participants.

Molecular Detection of Tick-Borne Pathogens in Stray Dogs and Rhipicephalussanguineus sensu lato Ticks from Bangkok, Thailand.

Canine tick-borne pathogens (CTBPs) such as Babesia vogeli, Ehrlichia canis, Anaplasma platys, Hepatozoon canis, and Mycoplasma haemocanis are important pathogens in dogs worldwide. Rhipicephalus sanguineus sensu lato, the main vector of several CTBPs, is the most common tick species found on dogs in Thailand. The present study identified CTBPs in dogs and ticks infested dogs. Samples (360 dog blood samples and 85 individual ticks) were collected from stray dogs residing in 37 temples from 24 districts in Bangkok and screened for CTBPs using molecular techniques. The most common CTBP found infecting dogs in this study was Ehrlichia canis (38.3%) followed by Mycoplasma haemocanis (34.2%), Hepatozoon canis (19.7%), Babesia vogeli (18.1%), and Anaplasma platys (13.9%), respectively. Furthermore, A. platys (22.4%) was the most common CTBP in ticks followed by M. haemocanis (18.8%), B. vogeli (9.4%), H. canis (5.9%), and E. canis (2.4%), respectively. The detection of CTBPs from the present study highlights the potential risk of infections that may occur in stray dogs and their ticks residing in Bangkok temples. These findings underline the importance of performing active surveys to understand the complexity of distributions of CTBPs in dogs and their ticks in Thailand.

Molecular detection of Giardia duodenalis and Cryptosporidium spp. from stray dogs residing in monasteries in Bangkok, Thailand.

Both Cryptosporidium spp. and Giardia duodenalis are enteric protozoan parasites that infect a wide variety of domestic animals as well as humans worldwide, causing diarrheal diseases. Giardia duodenalis assemblages C and D are specific to canine hosts and zoonotic assemblages A and B are also found in dogs as a reservoir host. In dogs, Cryptosporidium canis is the host-specific species while humans are infected by C. hominis and C. parvum and at least another 16 zoonotic Cryptosporidium species have been reported causing human infections, with C. meleagridis, C. viatorum, and C. ubiquitum being the most frequent. The objective of this study was to determine the prevalence of Cryptosporidium spp. and G. duodenalis from stray dogs in areas of Bangkok and to identify the species and assemblages. Fecal samples (540) were collected from dogs residing in 95 monasteries in 48 districts in the Bangkok metropolitan area. Nested Polymerase Chain Reaction (PCR) was performed using the ssu-rRNA gene for both parasites. In total, 3.0% (16/540) samples were positive for G. duodenalis, with most being G. duodenalis assemblage D (7/16) followed by assemblage C (7/16) and zoonotic assemblage A (2/16). The prevalence of Cryptosporidium spp. was 0.7% (4/540) based on the PCR results and all were the dog genotype C. canis. These results indicated that dogs residing in Bangkok monasteries poses a limited role as source of human giardiosis and cryptosporidiosis.

Evaluation of hematological alteration of vector-borne pathogens in cats from Bangkok, Thailand.

BACKGROUND: Cats can be carriers of infected arthropods and be infected with several vector-borne pathogens (VBPs) but there is limited knowledge about their pathogenic role in cats. This study aimed to assess the prevalence of some feline vector-borne agents by molecular technique and to characterize the hematological findings associated with these infections in a cat population from Bangkok Thailand. RESULTS: PCR was positive with at least one pathogen in 237 out of 372 subjects (63.7%), with prevalence of 39.5% (147/372) for Babesia spp., 36.9% (137/372) for hemoplasmas and 3.2% (12/372) for Hepatozoon spp. The cats older than 1 year were at significantly greater risk for VBPs infection (P = 0.001; OR = 1.43; 95% CI: 1.12 - 1.81) and hemoplasmas infection (χ2 = 10.8, df = 1; P < 0.0001; OR = 2.45; 95% CI: 1.49 - 4.01). A significant association between hematological findings and hemoplasma infection were identified in the present study. Besides, VBPs infection revealed more frequent in male cats (χ2= 6.38, df = 1, P = 0.01). Macrocytic hypochromic type of anemia was observed in cats infested with blood-sucking arthropods compared to the non-infested cats presented. CONCLUSIONS: The current study confirmed that Babesia, Hepatozoon and hemoplasmas had infected semi-domesticated cats in Bangkok, Thailand, with Babesia and hemoplasmas being dominant in prevalence. Some hematological findings were significantly associated with cats infected with vector-borne pathogens in this study including leukocyte count and platelets count that may help support veterinary technicians in diagnosis and appropriate treatment. Campaigns of VBPs monitoring in Bangkok emphasizing on the investigation of vectors and possible routes of the infection in animals should be conducted to prevent the transmission of the pathogens.

Seroprevalence of Toxoplasma gondii infection from water buffaloes (Bubalus bubalis) in northeastern and southern Thailand.

Toxoplasmosis is a parasitic disease resulting from infection with the apicomplexan Toxoplasma gondii (Nicolle et Manceaux, 1908), one of the world's most common parasites in warm-blooded animals, including humans. Sources of infection can be exposed to infected cat faeces, mother-to-child transmission during pregnancy, and notably, the consumption of undercooked contaminated meat of intermediate hosts. In Thailand, water buffaloes are highly valued for rice cultivation, traditional culture and meat production. Like several other mammalian species, these animals play a role as reservoirs of T. gondii, thus representing a threat to human health. The seroprevalence of T. gondii infection in swamp buffaloes was examined in southern and northeastern Thailand. In total, serum samples of 721 water buffaloes were collected from seven provinces (Ubon Ratchathani, Roi Et, Si Sa Ket, Surin, Buri Ram, Sakon Nakhon, and Songkhla) and examined for the presence of T. gondii infection using commercial latex agglutination test kits (TOXOCHECK-MT, Eiken Chemical Co., Tokyo, Japan). Of the 721 animals analysed, 49 (6.8%) were positive for T. gondii. Songkhla province had the highest seroprevalence (14.7%) among the seven provinces covered in this survey. There was a potential risk to local citizens of T. gondii infection identified by the present study, notably in northeastern Thailand, where despite lower seroprevalence consuming raw buffalo meat salad should be restricted to avoid the risk of zoonotic infections.

Investigation of Trypanosoma evansi infection in bullfighting cattle in Southern Thailand.

BACKGROUND AND AIM: Trypanosoma evansi infection has been reported in Thai livestock such as beef and dairy cattle. However, there is little information on T. evansi infection in bullfighting cattle in Southern Thailand. The aim of this study was to investigate the infection of T. evansi in bullfighting cattle presented for health checks at the Animal Hospital, Faculty of Veterinary Science, Prince of Songkla University, Thailand. MATERIALS AND METHODS: Blood and serum samples were collected from 177 bullfighting cattle from April 2016 to February 2017 after bullfighting matches. Animal inspected showed signs of fever, weight loss, or exercise intolerance. Investigation of T. evansi infection was tested using polymerase chain reaction (PCR) with TBR primers and using indirect enzyme-linked immunosorbent assay with T. evansi crude antigen. RESULTS: The seroprevalence of T. evansi in bullfighting cattle was 22.60% (40/177). The PCR results detected no parasite DNA in this study. However, bullfighting cattle may serve as T. evansi reservoirs. CONCLUSION: Health checking procedures for T. evansi should be promoted for bullfighting events so that infected animals can be quarantined in the preparatory stages of such events.

Prevalence of Tritrichomonas foetus infection in cats in Bangkok metropolitan area and in vitro drug sensitivity testing.

Tritrichomonas foetus is a causative agent of feline trichomonosis, resulting in large-bowel diarrhea in cats. Feline trichomonosis has been reported in the USA, Europe and some Asian countries but there is limited information for Thailand. This study investigated the prevalence of T. foetus infection in cats in the Bangkok metropolitan area and evaluated the in vitro efficacy of metronidazole (MDZ) and ronidazole (RDZ) against T. foetus Thai isolates. In total, 215 fecal samples were collected from 121 owned cats and 94 stray cats. All fecal samples were cultivated in InPouch™ TF-feline medium. Afterward, polymerase chain reaction (PCR) assays targeting the 5.8S rRNA gene, the ITS regions and DNA sequencing were used for the confirmation of T. foetus. The overall prevalence of T. foetus infection was 4.18% (9/215) based on cultivation and PCR. The sequencing results showed 100% homology to T. foetus sequences from GenBank. The average minimal lethal concentrations (MLCs) of MDZ were 333.33 and 66.67 µg/ml at 24 and 48 h, respectively. The average MLCs of RDZ were 29.16 and 12.5 µg/ml at 24 and 48 h, respectively. The MLC of the MDZ results revealed that T. foetus Thai isolates had a tendency to be MDZ-resistant. To the best of the authors' knowledge, this study was the first using in vitro cultivation and molecular techniques to report and confirm the presence of T. foetus in cats living in the Bangkok metropolitan area. Further studies are needed to determine the genuine infection rate of T. foetus in a greater population sample and the infection status in cats with signs of diarrhea in Thailand.