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    Molecular Characterization of Pseudomonas aeruginosa Isolated From Clinical Bovine Mastitis Cases
    (Kafkas Univ, Veteriner Fakultesi Dergisi, 2022) Aslantas, Ozkan; Turkyilmaz, Suheyla; Keskin, Oktay; Yucetepe, Ayfer Gullu; Buyukaltay, Kaan
    This study aimed to investigate the presence and distribution of virulence determinants and their antimicrobial susceptibilities of 44 Pseudomonas aeruginosa isolates obtained from clinical bovine mastitis cases. In addition, selected 6 P. aeruginosa isolates were further characterized using whole-genome sequencing (WGS). Based on the presence of T3SS-related genes, 25% of the isolates were found to carry exoU and/or exoS genes belonging to invasive (exoU-/exoS+, 18.2%) and cytotoxic (exoU+/exoS-, 6.8%) strains. But, none of the isolates carried both exoU and exoS genes. In terms of other virulence genes examined, various virulence gene profiles were observed among the isolates. The majority of the isolates (72.7%) were susceptible to all tested antimicrobials. Resistance rates to ciprofloxacin and carbapenems (imipenem and meropenem) were determined as 25% and 4.5%, respectively. WGS analysis indicated the presence of different resistome, but fosA genes in all isolates, and different combinations of mutations in gyrA, parC, oprD, efflux pump, and genes playing a role in the regulation of ampC gene expression. Different sequence types (STs) and serotypes were found in representative isolates with the occurrence of the O11-ST235 clone, which is a worldwide multidrug-resistant high-risk clone representing a serious public health threat. The findings of this study provide valuable information on P. aeruginosa isolated from clinical bovine mastitis cases and current antimicrobial resistance levels and virulence determinants.
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    Whole-genome sequencing of extended-spectrum ?-lactamase (ESBL)-producing Enterobacteriaceae from retail raw milk
    (Wiley, 2022) Aslantas, Ozkan; Yilmaz, Ebru Sebnem; Buyukaltay, Kaan; Kocabag, Hamide Deniz
    The contaminated products of food-producing animals have been proposed to lead the transmission of resistant bacteria to consumers. Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae, which were isolated from raw milk samples, were characterised using whole-genome sequencing in this study. Three confirmed ESBL and one plasmid-mediated AmpC beta-lactamase (pAmpC)-producing isolate were obtained. All of the ESBL-producing isolates showed a multidrug-resistant (MDR) phenotype, but the pAmpC-producing isolate was only resistant to beta-lactams. This study showed that raw milk can contain MDR bacteria that have several resistance determinants and highlighted the necessity of efficiently and routinely screening the products of food-producing animals.
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    Whole-Genome Sequencing-Based Characterization of Listeria monocytogenes from Food and Animal Clinical Cases
    (Kafkas Univ, Veteriner Fakultesi Dergisi, 2023) Aslantas, Ozkan; Buyukaltay, Kaan; Keskin, Oktay; Gullu Yucetepe, Ayfer; Adiguzel, Adem
    Listeriosis is a rare but severe foodborne infection caused by Listeria monocytogenes. In this study, we performed comparative whole-genome sequencing (WGS) on 28 Listeria monocytogenes from seven invasive listeriosis cases in animals and 21 food samples in Turkiye for the first time. Food isolates were delineated into eleven clonal complexes (CCs), namely CC1, CC2, CC3, CC8, CC9, CC20, CC69, CC124, CC155, CC204, ST3002. The isolates from meningoencephalitis cases were associated with CC1, whereas CC9 and CC7 were associated with the isolates from sheep abortus cases. All the isolates carried the fosX, lin, norB, and sul genes. In addition, emrC (n=15), bcrC (n=4), emrE (n=2), qacA (n=1), cadA (n=5) and cadC (n=1) genes, conferring resistance to stress and disinfectants were detected. Listeria pathogenicity island (LIPI)-1 and LIPI-2 were distributed in all isolates, but LIPI-3 was closely related to CC1, CC3, and ST3002 isolates. LIPI-4 was not found in any of the L. monocytogenes isolates. The Inc18(rep25) and Inc18(rep26) plasmids were found in 16 (57.1%) isolates. A total of 15 different intact prophage genomes ranging from one to three were detected in the genomes of 24 isolates. The hypervirulent CC1 and CC2 clones that pose a significant threat to food safety and public health were detected among food isolates. These findings highlight the importance of continuous surveillance of hypervirulent L. monocytogenes strains in different settings.