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Among the heterogeneous Pasteurellaceae family, Pasteurella multocida and Mannheimia haemolytica are the pathogenic species that cause enzootic pneumonia in cattle and sheep. This study was designed to characterize Pasteurella and Mannheimia species obtained from pneumonia cases in cattle and sheep. The lungs of 100 cattle and 100 sheep diagnosed with infectious pneumonia as a result of histopathological examination were analyzed for Pasteurellaceae members by phenotypic methods, the VITEK 2 Compact system (VITEK), and polymerase chain reaction (PCR). Antibiotic susceptibilities and phylogenetic analysis of the isolates were done by VITEK and 16S rRNA-PCR, respectively. Seven Pasteurella multocida and 9 Mannheimia haemolytica were identified. All strains were resistant to ampicillin and trimethoprim/sulfamethoxazole. High susceptibility to ceftiofur (100%, 7/7 and 88.89%, 8/9) and doxycycline (85.71%, 6/7 and 100%, 9/9) was detected among the P. multocida and M. haemolytica isolates, respectively. The minimum inhibitory concentration (MIC) for gentamicin was within the epidemiologic cutoff limits. The diversity of resistance genes (TEM, OXA-58, AadB, AadA25, Tet H, and Sul 2) was high and their frequency ranged from 22.22% to 100% (16/16) among the strains. Multidrug resistance (MDR) was detected as 100% (7/7) for P. multocida and 33.33% (3/9) for M. haemolytica strains. Based on the MDR, six resistotypes (A to F) were determined, with more among the P. multocida strains. An approach called 'antibiotic resistance marker-based genotyping' was introduced based on the presence of antibiotic resistance genes, and 8 genotypes (I to VIII) were determined, with more profiles (I to V) among the P. multocida strains. The 16S rRNA gene sequencing positioned the strains in two main phylogenetic clusters, and P. multocida strains were found to be more genetically close. A better understanding of bacterial behaviors related to antimicrobial susceptibility may aid communication with producers and veterinarians regarding appropriate antimicrobial stewardship. Phylogenetic clustering of strains can increase country-specific sequence data and create new taxa from a universal perspective. [ABSTRACT FROM AUTHOR]

This study was carried out to evaluate Brucella spp. isolated from various tissue samples of aborted sheep and bovine fetuses sent to the laboratory of Department of Microbiology, Faculty of Veterinary Medicine, Kafkas University between 2011 and 2023 years and determine the Brucella species and biotype diversity that carry a higher risk for abortion complications in these animals. In this context, 155 Brucella spp. isolates obtained from aborted fetuses were identified by species-specific Bruceladder PCR and biotyped using conventional biotyping methods. As a result of the study, B. melitensis and B. abortus were identified in 92.5% (n=74) and 7.5% (n=6) of sheep, B. abortus and B. melitensis were identified in 80% (n=60) and 20% (n=15) of cattle, respectively. B. melitensis biotype 2 in sheep and B. abortus biotype 3 in cattle were found as the dominant biotypes in these definitive hosts. In the Kars region, where brucellosis is endemic, while the biotype responsible for cattle brucellosis (B. abortus biotype 3) maintained its dominance over a 20-year period, there is a profile change from B. melitensis biotype 3 to B. melitensis biotype 2 in sheep. Considering the period covered by the study and the sample size analyzed, the data obtained provide up-to-date and important information about Brucella species and biotypes in Kars region and the animal species that host these agents. [ABSTRACT FROM AUTHOR]