Molecular prevalence of Toxoplasma gondii and Trypanosoma evansi in recently calved female cattle from Phayao, Thailand.

Background and Aim: Toxoplasma gondii and Trypanosoma evansi, the zoonotic protozoa responsible for toxoplasmosis and trypanosomiasis, are significant threats to the productivity and financial stability of livestock farming. T. gondii can be transmitted horizontally through ingestion of fecal oocysts and T. evansi through arthropod vectors. In addition, both species can be transmitted from mother to fetus through the placenta. This study aimed to assess the molecular prevalence of T. gondii and T. evansi transplacental-transmitted protozoans and to identify the epidemiological risk factors in recently calved female cattle across Phayao, Thailand. Materials and Methods: We collected 106 bovine placentas from beef and dairy cow full-term pregnancies in Phayao, Thailand. T. gondii and T. evansi DNA were detected using targeted B1 gene and expression site-associated gene (ESAG) species-specific polymerase chain reaction (PCR), respectively. Results: Forty-three placentas were positive for T. gondii B1 PCR, whereas only one was positive for T. evansi ESAG PCR, resulting in an overall prevalence of transplacental-transmitted protozoan infection of 41.5% (44/106). The prevalence of T. gondii and T. evansi was 40.6% (43/106) and 0.9% (1/106), respectively. No significant correlation was found between T. gondii infection and various risk factors, including locality, age, and cattle type. Conclusion: The prevalence of transplacental-transmitted protozoan T. gondii infection was high among female cattle in Phayao, Thailand, whereas the prevalence of T. evansi infection was notably lower. Although the conventional modes of transmission differ between these two parasites, the transplacental transmission of T. evansi and especially T. gondii may play a crucial role in the persistence of these protozoan species in this area.

Molecular detection and dense granule antigen 6 genotyping of feline Toxoplasma gondii in Phayao, Thailand.

Background and Aim: Globally, toxoplasmosis is an important zoonotic parasite infection of many warm-blooded animals (including humans). Toxoplasma gondii oocysts are widespread, and their contamination can be primarily attributed to the members of the Felidae family. This study aimed to estimate the prevalence and determine the dense granule antigen 6 (GRA6) genotype of T. gondii among domestic cats in the Phayao Province, Thailand. Materials and Methods: A total of 124 fecal samples were collected from owned cats in the Muang district, Phayao, Thailand, from January to December 2020. Fecal samples were tested for the presence of T. gondii DNA using targeted B1 gene polymerase chain reaction (PCR) amplification, and positive samples were subsequently analyzed for their T. gondii genotype through PCR-restriction fragment length polymorphism (RFLP) analysis and sequencing of the GRA6 gene. Results: Among the 124 samples, 46 (37.1%) were tested positive for T. gondii. Only 10 positive DNA samples were successfully amplified for the GRA6 marker. Subsequent PCR-RFLP and sequence analyses indicated that all T. gondii isolates from cats in Phayao belonged to GRA6 genotype I. Conclusion: Data revealed that toxoplasmosis is remarkably distributed among (studied) domestic cats in Phayao, Thailand. Moreover, the virulent GRA6 allele was found to be circulated among domestic cats in this area. However, no significant correlation was observed between infection rates and different risk factors, which indicated that pet cats of any age, gender, or breed have similar risks of being infected with T. gondii. Our results further suggested that infective oocysts of T. gondii are widely distributed and that environmental contamination with these oocysts will introduce more risks of disease transmission to humans and other animals.

Identification and expression of a transforming growth factor beta (TGF-ß) homologue in the tropical liver fluke Fasciola gigantica.

Liver flukes, Fasciola spp., are veterinary and medically important parasites infecting numerous species of economically important animals in addition to humans on a global scale. The components of transforming growth factor beta (TGF-ß) signalling are widely distributed throughout the animal kingdom and are considerably conserved. Through shared common signal transduction mechanisms, crosstalk of TGF-ß signalling between a host and the parasite during infection is possible. Herein, we have identified and undertaken the molecular characterisation of a putative TGF-ß homologue from the tropical liver fluke F. gigantica (FgTLM). A FgTLM cDNA was 3557 bp in length, it encoded for 620 amino acid polypeptide which consisted of 494 amino acids of prodomain and 126 amino acids comprising the mature protein. FgTLM displayed characteristic structures of mammalian TGF-ß ligands that were unique to the inhibin-ß chain, monomer of activin. A phylogenetic analysis revealed the high degree of conservation with TGF-ß molecules from trematode species. Interestingly, the sequence of amino acid in the active domain of FgTLM was completely identical to FhTLM from F. hepatica. FgTLM expressed throughout the lifecycle of F. gigantica but was highly expressed in developmental active stages. The dynamics of expression of FgTLM during the developmental stages of F. gigantica was comparable to the pattern of TGF-ß expression in F. hepatica. Our findings demonstrated that FgTLM exhibits a high level of similarity to FhTLM in the context of both amino acid sequence and the life stage expression patterns. These similarities underline the possibility that the FgTLM molecule might have the same properties and functions as FhTLM in biological processes of the immature parasites and host immune evasion. Consequently, the specific biological functions of FgTLM on either parasite or relevant hosts need to be defined experimentally.

Occurrence of fluke infection in beef cattle around Phayao Lake, Phayao, Thailand.

BACKGROUND AND AIM: Ruminant flukes, including Fasciola spp. and Paramphistomum spp., are recognized as the significant parasites in livestock worldwide. Cattle infected by these fluke results in slower growth rate and productivity losses contributing to economic losses. In case of Fasciola spp., the parasite is considered as an important zoonotic parasite. This study aimed to investigate the prevalence of fluke invasion in beef cattle around Phayao Lake, Phayao, Thailand, between January 2019 and June 2019. MATERIALS AND METHODS: A total of 311 fecal samples from beef cows reared nearby Phayao Lake were examined for the presence of fluke eggs by formalin-ethyl acetate sedimentation and subsequently identified by morphology together with methylene blue staining. RESULTS: The overall prevalence of fluke invasion in beef cattle around Phayao Lake was 33.8% (105/311). The prevalence of rumen fluke and liver fluke was 25.4% (79/311) and 8.4% (26/311), respectively. Mixed infection of both species was found at 1.9% (6/311). CONCLUSION: Age of cattle was observed to be associated with invasion rate of all flukes, particularly in the ages over 4 years, which was the highest group of invasion. However, other risk factors, including gender, breed, and location of animals, were not found to be related. This study provides the current status of natural fluke invasion among the beef cattle in Phayao, Thailand, which could be critical for designing the control program of these parasites.

Prevalence of vertically transmitted Neospora caninum amongst beef cattle in Phayao, Thailand.

Neospora caninum, the causative agent of neosporosis, is recognised as a significant trigger of abortion and productivity losses in cattle worldwide. Current information regarding to the prevalence of N. caninum in Thailand is limited due to the limitations of detection methods and the difficulty of recovering of viable parasite. Vertical transmission is the main route of N. caninum infection in cattle. Therefore, detection of N. caninum DNA in placental tissue could be a possible means of laboratory diagnosis of neosporosis in live animals, particularly in the context of transplacental transmission. The aim of this study was to investigate the prevalence of transplacentally transmitted N. caninum infection in female beef cattle in the northern Thai province of Phayao by detection of N. caninum DNA in bovine placenta by PCR. A total of 96 bovine placentas were collected from 7 districts of Phayao. Our result indicated that overall PCR prevalence of N. caninum in cattle in this area was 36.5% varying from 16.7-50.0% between districts. The districts with the highest prevalence of infection were Muang (50.0%) and Mae Chai (44.7%). The proportion of N. caninum infection was quite high suggesting that newborn calves were at risk of congenital infection. This study provides a current snapshot of the status of bovine neosporosis in Phayao which could lead to the development of effective strategies for prevention and control this disease.