RESUMO
Background and Aim: Filarial nematode typically produces a larval stage (microfilariae) in the bloodstream of vertebrate hosts, where microfilariae reside in the blood or subcutaneous tissues. Filarial nematodes cause human diseases, such as river blindness and elephantiasis, which are widely studied. However, in avian species, they are overlooked because they are nonpathogenic. In Thailand, microfilaria can be found in wild birds and domestic chickens. Recently, an increase in the number of blood samples submitted to veterinary diagnostic laboratories may have increased the number of microfilariae. Therefore, knowledge about filarial species and reliable detection methods are important. Therefore, this study aimed to investigate the efficacy of buffy coat smear and polymerase chain reaction (PCR)-based methods for the detection of microfilaria in domestic chickens. In addition, parasites were identified using the sequence of the cytochrome c oxidase subunit 1 (COX1) gene. Materials and Methods: Giemsa-stained buffy coat smears from a previous study were reanalyzed. These available buffy coat smears were prepared from 55 domestic chickens raised as backyard free-ranging in Southern Thailand. Fifty-seven frozen genomic DNA extracted from chicken blood were used to detect the presence of the COX1 gene in Onchocercidae nematodes. The nested PCR protocol for amplification of the OnchoCOI_R2-OnchoCOI_R2 fragment of the COX1 gene was applied from a previous report. Sequences of COX1 were analyzed to identify Onchocercidae nematodes and if they were single or mixed infections. We constructed Bayesian phylogenetics to identify parasites and assessment of the relationship between filarial nematodes in avian species and other vertebrate hosts. Results: Buffy coat smears from 15 samples revealed microfilaria. Of these 15 samples, only eight were positive for COX1 nested-PCR amplification. The other two buffy coat-negative samples were also positive for nested-PCR. Sequencing of these 11 nested PCR-positive samples revealed that almost all of them were Onchocercidae nematodes. Bayesian phylogenetic analysis showed that chicken Onchocercidae spp. were grouped with other avian filarial nematodes. However, all chickens Onchocercidae spp. showed a double peak in the sequencing chromatogram, indicating mixed filarial infection (species or haplotypes). Therefore, no chicken Onchocercidae sequence was deposited on National Center for Biotechnology Information, GenBank. Conclusion: Giemsa-stained buffy coat smear was a reliable method for the detection of chicken microfilaria in routine veterinary diagnostic laboratories. Development of a new PCR-based method is necessary. This method may provide greater sensitivity and specificity of detection. In addition, the PCR method allowed us to access the genetic characteristics of nematodes, which helped us maximize our knowledge of nematodes. Further investigations, such as the pathogenicity of filarial nematodes in chickens and their potential vectors, are required.
RESUMO
Background and Aim: Methicillin-resistant coagulase-positive staphylococci (MRCoPS) cause pyoderma, dermatitis, and nosocomial infection. Numerous factors, including indiscriminate antimicrobial use (AMU) in veterinary medicine, cleaning practices, and AMU in hospitals, contribute to MRCoPS. However, the relationship between hospital age and MRCoPS has not yet been investigated. This study aimed to estimate the prevalence of MRCoPS in the treatment and operation rooms of new, middle-aged, and old veterinary hospitals. Materials and Methods: Samples were collected from small animal hospitals in Surat Thani, Nakhon Si Thammarat, and Songkhla in Thailand. Hospitals were defined as those that had been in operation for 5 years (new, n = 5), 5-15 years (middle-aged, n = 6), or >15 years (old, n = 3). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used to identify 280 samples, and duplex polymerase chain reaction was used to identify resistance genes (mecA and blaZ). The VITEK2® automated system was then used to determine the minimum inhibitory concentration. Results: A total of 57 Staphylococcus species were identified and classified as coagulase-positive staphylococci (CoPS) (22/57, 38.60%) or coagulase-negative staphylococci (35/57, 61.40%), respectively. Nine of the 22 CoPS (40.90%) harbored the mecA gene, and 21 isolates (95.45%) harbored the blaZ gene. Interestingly, more MRCoPS was found in new hospitals (six isolates) than in middle-aged (one isolate) and old hospitals (two isolates), although there was no statistically significant difference in the presence of MRCoPS across new, middle-aged, and old veterinary hospitals (p = 0.095), Kruskal-Wallis test. There is a need for further detailed studies, including an increase in the number of hospitals in various locations. Conclusion: MRCoPS is a nosocomial pathogen that causes zoonotic and recurrent infections in veterinary hospitals. The prevalence of MRCoPS tended to be higher in new hospitals. Areas with heavy animal contact, such as hospital floors, are areas of particular concern, and cleaning/disinfection of these areas must be highlighted in hygiene regimens.