Canine filariasis is caused by several nematode species, such as Dirofilaria immitis, Dirofilaria repens, Brugia pahangi, Brugia malayi, and Acanthocheilonema reconditum. Zoonotic filariasis is one of the world’s neglected tropical diseases. Since 2000, the World Health Organization (WHO) has promoted a global filarial eradication program to eliminate filariasis by 2020. Apart from vector control strategies, the infection control of reservoir hosts is necessary for more effective filariasis control. In addition, many studies have reported that Wolbachia is necessary for the development, reproduction, and survival of the filarial nematode. Consequently, the use of antibiotics to kill Wolbachia in nematodes has now become an alternative strategy to control filariasis. Previously, a case of subconjunctival dirofilariasis caused by Dirofilaria spp. has been reported in a woman who resides in the center of Bangkok, Thailand. Therefore, our study aimed to principally demonstrate the presence of filarial nematodes and Wolbachia bacteria in blood collected from domestic dogs from the Bangkok Metropolitan Region, Thailand. A total of 57 blood samples from dogs with suspected dirofilariasis who had visited veterinary clinics in Bangkok were collected. The investigations for the presence of microfilaria were carried out by using both microscopic and molecular examinations. PCR was used as the molecular detection method for the filarial nematodes based on the COI and ITS1 regions. The demonstration of Wolbachia was performed using PCR to amplify the FtsZ gene. All positive samples by PCR were then cloned and sequenced. The results showed that the filarial nematodes were detected in 16 samples (28.07%) using microscopic examinations. The molecular detection of filarial species using COI-PCR revealed that 50 samples (87.72%) were positive; these consisted of 33 (57.89%), 13 (22.81%), and 4 (7.02%) samples for D. immitis, B. pahangi, and B. malayi, respectively. While the ITS1-PCR showed that 41 samples (71.93%) were positive—30 samples (52.63%) were identified as containing D. immitis and 11 samples (19.30%) were identified to have B. pahangi, whereas B. malayi was not detected. Forty-seven samples (82.45%) were positive for Wolbachia DNA and the phylogenetic tree of all positive Wolbachia was classified into the supergroup C clade. This study has established fundamental data on filariasis associated with Wolbachia infection in domestic dogs in the Bangkok Metropolitan Region. An extensive survey of dog blood samples would provide valuable epidemiologic data on potential zoonotic filariasis in Thailand. In addition, this information could be used for the future development of more effective prevention and control strategies for canine filariasis in Thailand.

Babesia spp., Theileria orientalis, and Anaplasma marginale are significant tick-borne pathogens that affect the health and productivity of cattle in tropical and subtropical areas. In this study, we used PCR to detect the presence of Babesia bovis, Babesia bigemina, and T. orientalis in 279 beef cattle from Western Thailand and A. marginale in 608 beef cattle from the north, northeastern, and western regions. The PCRs were performed using species-specific primers based on the B. bovis spherical body protein 2 (BboSBP2), B. bigemina rhoptry-associated protein 1a (BbiRAP-1a), T. orientalis major piroplasm surface protein (ToMPSP), and A. marginale major surface protein 4 (AmMSP4) genes. To determine the genetic diversity of the above parasites, amplicons of B. bovis and B. bigemina ITS1-5.8s rRNA gene-ITS2 regions (B. bovis ITS, B. bigemina ITS), ToMPSP, and AmMSP4 genes were sequenced for phylogenetic analysis. PCR results revealed that the prevalence of B. bovis, B. bigemina, T. orientalis, and A. marginale in the Western region was 11.1, 12.5, 7.8, and 39.1 %, respectively. Coinfections of two or three parasites were observed in 17.9 % of the animals sampled. The study revealed that the prevalence of A. marginale in the western region was higher than in the north and northeastern regions (7 %). Sequence analysis showed the BboSBP2 gene to be more conserved than B. bovis ITS in the different isolates and, similarly, the BbiRAP-1a was more conserved than B. bigemina ITS. In the phylogenetic analysis, T. orientalis MPSP sequences were classified into types 3, 5, and 7 as previously reported. A. marginale MSP4 gene sequences shared high identity and similarity with each other and clustered with isolates from other countries. This study provides information on the prevalence and genetic diversity of tick-borne pathogens in beef cattle and highlights the need for effective strategies to control these pathogens in Thailand.

Over the last decade, research interest in defining how extracellular vesicles (EVs) shape cross‐species communication has grown rapidly. Parasitic helminths, worm species found in the phyla Nematoda and Platyhelminthes, are well‐recognised manipulators of host immune function and physiology. Emerging evidence supports a role for helminth‐derived EVs in these processes and highlights EVs as an important participant in cross‐phylum communication. While the mammalian EV field is guided by a community‐agreed framework for studying EVs derived from model organisms or cell systems [e.g., Minimal Information for Studies of Extracellular Vesicles (MISEV)], the helminth community requires a supplementary set of principles due to the additional challenges that accompany working with such divergent organisms. These challenges include, but are not limited to, generating sufficient quantities of EVs for descriptive or functional studies, defining pan‐helminth EV markers, genetically modifying these organisms, and identifying rigorous methodologies for in vitro and in vivo studies. Here, we outline best practices for those investigating the biology of helminth‐derived EVs to complement the MISEV guidelines. We summarise community‐agreed standards for studying EVs derived from this broad set of non‐model organisms, raise awareness of issues associated with helminth EVs and provide future perspectives for how progress in the field will be achieved.

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Background and Aim: Canine babesiosis, a tick-borne parasitic disease, is caused by the hemoprotozoa, Babesia vogeli, and Babesia gibsoni. Infection with these parasites, which is endemic globally, leads to life-threatening immunosuppression in dogs. The merozoites invade the red blood cells (RBCs) of infected dogs. Ehrlichia canis, an intracellular bacterium that infects monocytes, is transmitted by the same tick species (Rhipicephalus sanguineus) during blood consumption and coinfection with B. vogeli and E. canis has been reported. Although the hematology and biochemistry of canine babesiosis have been studied, more studies are needed to develop a better understanding of the hematobiochemical and molecular profiles associated with cases of single infection and coinfection of canine babesiosis in Thailand. This study aimed to investigate the hematological, biochemical, and molecular profiles of B. vogeli infection and E. canis coinfection. Materials and Methods: The study included 33 B. vogeli–positive blood samples and 11 E. canis–coinfected blood samples. To exclude coinfection with Hepatozoon canis and Anaplasma platys, only dogs with B. vogeli infection and B. vogeli–E. canis coinfection were included in the study. A multiplex polymerase chain reaction (PCR) assay was conducted to detect B. vogeli, E. canis, and H. canis, and a conventional PCR assay was conducted for the detection of A. platys. Besides, the PCR assay and sequencing, comprehensive data analysis was conducted, including a microscopic blood parasite examination and hematological and biochemical data analysis. Results: The comparison of the hematobiochemical data between the B. vogeli–positive and E. canis coinfection groups identified that there were statistically significant differences in the RBC parameters, including RBC count, hemoglobin concentration, hematocrit, and RBC distribution width (p=0.001). Neither B. vogeli infection nor coinfection with E. canis was associated with the sex, breed, recorded clinical signs, geographic origin of the dog and also B. vogeli 18S rRNA gene sequencing results. Conclusion: Coinfection with E. canis increased the severity of babesiosis. The pathogenic mechanisms underlying this infection, such as destruction of RBCs, require further investigation. This study may enhance diagnosis, treatment, and prevention of canine babesiosis.

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The stable fly, Stomoxys calcitrans (Diptera: Muscidae), and the horse fly, Tabanus megalops (Diptera: Tabanidae), are important ectoparasites of livestock in Thailand. These species affect animal health and cause economic losses. This study investigated the insecticidal activity of Plectranthus amboinicus essential oil against S. calcitrans and T. megalops through contact and fumigant toxicity tests and evaluated the effects of the essential oil on these flies through histopathological and scanning electron microscopic (SEM) studies. The results of the contact toxicity test indicated that the median lethal dose against S. calcitrans and T. megalops was 12.05 and 131.41 µg/fly, and the 90% lethal dose was 45.53 and 200.62 µg/fly, respectively. The results of the fumigant toxicity test showed that the median lethal concentration against S. calcitrans and T. megalops was 1.34 and 7.12 mg/L air, and the 90% lethal concentration was 4.39 and 30.37 mg/L air, respectively. Histopathology revealed neuronal degeneration in the brain of S. calcitrans and interstitial neuronal edema of the brain and ovarian necrosis in T. megalops. No external morphological changes were observed via SEM. Given its insecticidal properties against S. calcitrans and T. megalops, P. amboinicus essential oil could be developed into a natural insecticide to control these fly species.