Determination of Genetic Variations of Toll-Like Receptor (TLR) 2, 4, and 6 with Next-Generation Sequencing in Native Cattle Breeds of Anatolia and Holstein Friesian

In recent years, the focus of disease resistance and susceptibility studies in cattle have been on determining patterns in the innate immune response of key proteins, such as Toll-like receptors (TLR). In the bovine genome, there are 10 TLR family members and, of these, TLR2, TLR4, and TLR6 are specialized in the recognition of bacterial ligands. Indigenous cattle breeds of Anatolia have been reported to show fewer signs of clinical bacterial infections, such as bovine tuberculosis and mastitis, and it is hypothesized that this might be due to a less stringent genetic selection during breeding. In contrast, Holstein-Friesian cattle have been under strong selection for milk production, which may have resulted in greater susceptibility to diseases. To test this hypothesis, we have compared the TLR2, TLR4, and TLR6 genes of Anatolian Black (AB), East Anatolian Red (EAR), South Anatolian Red (SAR), Turkish Grey (TG), and Holstein (HOL) cattle using next-generation sequencing. The SAR breed had the most variations overall, followed by EAR, AB, TG, and HOL. TG had the most variations for TLR2, whereas SAR had the most variations in TLR4 and TLR6. We compared these variants with those associated with disease and susceptibility traits. We used exon variants to construct haplotypes, investigated shared haplotypes within breeds, and proposed candidate haplotypes for a disease resistance phenotype in Anatolian cattle breeds

Molecular detection and genotyping of microsporidia species in chickens in Turkey

Microsporidia are obligate intracellular pathogens that infect various hosts including invertebrates and vertebrates. Despite the importance, knowledge on the prevalence and molecular characteristics of microsporidia in chickens is limited, and no data are available for Turkey. A total of 300 fecal samples from chickens in the Central Anatolia Region of Turkey were analyzed by using a nested polymerase chain reaction assay targeting the rRNA internal transcribed spacer (ITS) region for the common microsporidia species. Corresponding PCR amplicons from the positive samples were sequenced for genotyping. Enterocytozoon bieneusi was identified in 22 (7.3 %) samples, whereas Encephalitozoon spp. was not detected. The prevalence of E. bieneusi was 63.6 % in Kayseri and 36.4 % in Nevsehir provinces, and 8.8 % in soft fecal samples and 9.7 % in diarrhoeic samples. No infections were found in Kirsehir Province. Significant differences were found for the distribution of E. bieneusi among provinces and fecal conditions. Infections were found only in free-range chickens. As a result of ITS region sequencing, two genotypes were characterized. The novel genotype ERUNT1 (n = 21), belonging to zoonotic group 1, was the most common genotype throughout the study area. The other known genotype, ERUSS1 (n = 1), had a restricted distribution and was previously detected in cattle and sheep in the same region. Our study provides the first data on microsporidia species from chickens in Turkey. None of these genotypes have been reported in humans; thus, the risk potential for public health is limited but needs further investigation

Molecular Prevalence of Three Chicken Gastrointestinal Tract Pathogens and Phylogenetic Characterization of Tetratrichomonas gallinarum in Türkiye

Several species of parasites infect chickens and can cause economic losses. Histomonas meleagridis, its intermediate host Heterakis gallinarum, and Tetratrichomonas gallinarum are the most common parasites of poultry. The current study aimed to determine the molecular prevalence and phylogenetic relationships of H. meleagridis, He. gallinarum, and T. gallinarum in chickens in Central Anatolia Region of Türkiye. For this, a total of 100 fecal specimens from chickens were analyzed by using a PCR assay targeting the 18S rRNA gene region of H. meleagridisand T. gallinarum and the mtDNA COI gene region of He. gallinarum. PCR analysis identified T. gallinarum in 11 (1.1%) specimens, whereas other species were not found in all the examined pecimens. Positive specimens were detected only in backyard chickens. Sequence analyses identified two novel genotypes named TRTgal1 and TRTgal3, and one known genotype (TRTgal2) of T. gallinarum. The TRTgal2 genotype was found to be identical to the human genotype (AY247746) and the four avian genotypes. Phylogenetic analyses of the obtained genotypes clustered in separate monophyletic clades. Our study provides the first data on T. gallinarum in chickens in Türkiye and contributes to public health with the identified zoonotic genotype and knowledge of the epidemiology of this parasite