650 KB37 KB200420252024Abd-El Razik, Khaled Abd-EL HamidEid Elsaid Abdelaziz, SolimanElaal, Ahmed AbdEl-Alfy, El-SayedElkenany, Rasha M.El-Khodery, SabryGioushy, Magdyštevilka:4letnik:61str. 271-279DOI:10.26873/SVR-1882-2024ISSN:1580-4003COBISSID_HOST:227464195URN:URN:NBN:SI:doc-IAQRZHLNenslZaložba Univerze v LjubljaniSlovenian veterinary researchantimicrobial susceptibilitychronic mastitisMycoplasma bovissequence analysisvirulence genesMolecular characterization, virulence, and antimicrobial susceptibility of mycoplasma bovisassociated with chronic mastitis in dairy cows|Mycoplasma bovis (M. bovis) is the most common Mycoplasma species, which has a growing impact on the dairy industry. The purpose of this study was to in-vestigate the molecular characterization, virulence, and antibiotic susceptibility of M. bo-vis isolates from dairy cows with chronic mastitis in Egypt. Eighty-four composite milk samples from mastitic cows were aseptically collected from dairy farms in Egypt. Based on microbiological examination and the polymerase chain reaction (PCR) technique targeting the 16S rRNA, 14 (16.7%) of all milk samples were positive for Mycoplasmaspp. PCR targeting M. bovis-specific gene identified six (7.14%) of the 14 mycoplasma isolates as M. bovis. PCR assays for different virulence genes showed that all M. bovisisolates exhibited the presence of vspA gene, while other virulence genes (uvrC, gap, and p40 pseudogenes) were determined in only two M. bovis isolates (2/6). The 16S rRNA gene phylogenetic analysis demonstrated 100% homology with reference strains of M. bovis isolated from different species and locations. When compared to other iso-lates in the GenBank, the amino acid sequence alignment of our isolate VspA-like pro-tein indicated a distinct mutation. The in vitro antimicrobial susceptibility testing of the six M. bovis isolates in this study to seven antimicrobial drugs revealed that tilmycosin and tylosin had the lowest minimum inhibitory concentrations (MIC) values (?1 µg/mL), while danofloxacin, streptomycin and florfenicol had the highest MIC values (<4 µg/mL). Nonetheless, this study showed the virulence of M. bovis in dairy cows in Egypt, and macrolides were found to be the most potent compounds in vitro against all tested isolates, but further studies in nationwide surveys are neededTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Ljubljani, Veterinarska fakulteta