Detection of SNPs and benzimidazole resistance in strongyle nematode eggs of horses by allele-specific PCR.

This study was conducted to determine single nucleotide polymorphisms (SNPs) and the benzimidazole (BZ) resistance in strongyle nematode egg populations in horses using molecular techniques. A total of 200 fecal samples were collected from horses in 26 farms in two provinces (Kayseri and Nevsehir) of the Central Anatolia Region of Türkiye between May and August 2022. The flotation method was used to detect strongyle nematode eggs in the fecal samples of the horses. Afterward, strongyle nematode eggs were collected, and the allele-specific polymerase chain reaction (AS-PCR) technique was used to detect the BZ resistance. BZ-susceptible and BZ-resistant PCR products were sequenced to determine single nucleotide polymorphisms (SNPs) in the ß-tubulin isotype 1 gene. The strongyle nematode eggs were determined in 85 (42.5%) out of 200 fecal samples. AS-PCR detected 50.58% (43/85) BZ-resistant (homozygous resistant) and 36.4% (31/85) BZ-susceptible (homozygous susceptible) genes in the strongyle eggs. Both BZ-resistant and BZ-susceptible genes (heterozygous) were determined in 11 samples. BZ-resistant and BZ-susceptible allele frequencies were determined as 57.0% (48.5/85) and 43.0% (36.5/85), respectively. SNPs were detected only in codon 200 of the ß-tubulin isotype 1 gene in four sequenced isolates of the two resistant and two susceptible isolates. This study is the first molecular report on BZ resistance in strongyle nematode eggs in horses in Türkiye. The widespread prevalence of BZ-resistant alleles in equine strongyle nematodes shows the requirement for the immediate usage of other anthelmintics instead of the BZ group drugs for the effective management and control of equine strongyle nematodes.

Molecular Prevalence and Phylogenetic Characterization of Enterocytozoon bieneusi in Sheep in the Van Region

OBJECTIVE: In this study, we aimed to determine the prevalence of Enterocytozoon bieneusi in healthy sheep in Van province using molecular techniques and to reveal genotypes of the detected isolates. METHODS: A total of 200 healthy appearance sheep comprise 38 male and 162 female, 32 preweaned, 38 postweaned lamb and 130 adult sheep from several farms in the Van region were included in the study between May and September 2021. Genomic DNA (gDNA) extractions were utilized on fecal samples collected from sheep by commercial kits, and E. bieneusi DNA was investigated by Nested polymerase chain reaction (PCR) amplifying ITS rRNA in the gDNA isolates. PCR products of the positive isolates were subjected to sequence analyze for genotyping and phylogenetic analyses of E. bieneusi. RESULTS: E. bieneusi DNA was determined in 16 out of 200 examined sheep fecal gDNA samples (8.0%) by Nested PCR. The highest E. bieneusi prevalence was determined in preweaned lambs with a rate of 18.8%. This was followed by postweaned lambs and adult sheep with a prevalence of 10.5% and 4.6%, respectively. The prevalence of the infection in males and females was 7.9% and 9.3%, respectively. All the ITS rRNA amplicons from 16 positive isolates were subjected to sequence analyses for genotyping and phylogenetic analyses. Sequence analyses revealed that all the isolates determined in sheep belonged to the BEB6 genotype and clustered in genogroup 2 of E. bieneusi with the BEB6 isolates from different hosts in several countries. CONCLUSION: Molecular epidemiological data on the prevalence of E. bieneusi in sheep in Turkey were obtained with this study and the common genotype was determined as BEB6 in the research area. The obtained data contribute to the molecular epidemiology and diversity of E. bieneusi in sheep.

Occurrence and molecular characterization of Enterocytozoon bieneusi in water buffaloes (Bubalus bubalis) in Turkey.

Microsporidia are obligate intracellular fungus-like parasites that infect humans and animals worldwide. However, there is limited epidemiological data on the occurrence and molecular diversity of microsporidia in buffaloes worldwide. In the present study, fecal samples of 300 water buffaloes (Bubalus bubalis) in Kayseri, Sivas, and Samsun provinces of Turkey were investigated using two nested PCR assays targeting the rRNA of E. bieneusi and Encephalitozoon spp. All the fecal samples from water buffalo were found to be negative for Encephalitozoon spp. PCR positive isolates of E. bieneusi were bidirectionally sequenced for genotyping and phylogenetic analyses. Enterocytozoon bieneusi was the only microsporidian species identified in 8 water buffaloes with an overall molecular prevalence of 2.7%. Two known genotypes, YNDCEB-90 (n = 5) and J (n = 3) were identified by ITS sequence analysis. The YNDCEB-90 and J genotypes fall into zoonotic Group 1 and 2 of E. bieneusi in the phylogenetic tree, respectively. These findings suggested that water buffalo in Turkey are harbouring zoonotic genotypes of E. bieneusi and may have a significant risk for zoonotic transmission to humans. This is the first report of detecting E. bieneusi genotypes J and YNDCEB-90 in water buffaloes. Further insight into the epidemiology of E. bieneusi in water buffaloes in different geographical areas in Turkey will be highly important to have determined the public health significance of this pathogen.