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  • Küçük Resim
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    Characterization of Campylobacter spp. Strains Isolated From Wild Birds in Turkey
    (Frontiers Media Sa, 2021) Kuerekci, Cemil; Sakin, Fatih; Epping, Lennard; Knuever, Marie-Theres; Semmler, Torsten; Stingl, Kerstin
    Turkey is an important stopover site for many migrating birds between Europe, Asia and Africa. Campylobacter spp. are frequently found in wildlife, in particular waterfowl, and distinct strains are disseminated within this reservoir. In this study, 183 wild birds of hunting areas in Turkey were collected and thermophilic Campylobacter spp. from cloacal swabs were isolated at a prevalence of 5.2% from song thrushes (6/116) and 93% from Eurasian coots (41/44). After PCR species differentiation and flaA restriction profiles determination, C. jejuni and C. coli strains were further investigated by whole genome sequencing. PCR target amplification of the ceuE gene, commonly used for C. coli species-identification was inefficient and even hampered in one isolate. A close look on the ceuE sequence revealed that various mismatches in the ceuE oligo annealing sites caused less efficient diagnostic detection. All C. coli isolates belonged to the environmental clade II and clade III, for which thirty-six novel MLST types were identified. Further single nucleotide polymorphism (SNP) analysis showed a high genomic divergence between the C. coli isolates. High variability was also implicated for putative plasmid-located genes detected in 51% of the C. coli isolates. Distinct gene variants in clades II and III C. coli were identified by a k-mer analysis. After substracting k-mers in common with C. coli clade I database, 11 and 35 distinct genes were identified in clades II and III isolates, mainly involved in surface structures and modifications as well as signal transduction, suggesting niche adaptation of C. coli strains in wild birds. All strains were susceptible against (fluoro-)quinolones, erythromycin, tetracycline, gentamicin and only one isolate was resistant against streptomycin, suggesting that the sensitive phenotype was due to absence of selective pressure and niche separation in wild birds in Turkey. We conclude that Campylobacter spp. isolates from wildlife and environmental sources are still scarce in the databases and that there is a need for more studies on thermophilic Campylobacter spp. from different places all over the world in order to complement our understanding on dissemination and adaptation to distinct niches of this global food-borne pathogen.
  • Küçük Resim
    Öğe
    Evaluation of bulk tank raw milk and raw chicken meat samples as source of ESBL producing Escherichia coli in Turkey: Recent insights
    (Wiley, 2019) Kuerekci, Cemil; Osek, Jacek; Aydin, Muhsin; Tekeli, Ibrahim Ozan; Kurpas, Monika; Wieczorek, Kinga; Sakin, Fatih
    Extended spectrum beta-lactamase producing Escherichia coli (ESBL-EC) was detected in 86.6% of chicken and 22.6% of bulk tank milk (BTM) samples. Pulsed-field gel electrophoresis analysis revealed 49 distinct restriction profiles among 66 isolates, and 62.3% of the isolates carried the bla(CTX-M) gene, among which CTX-M-1 was found to be the predominant ESBL types in chicken isolates, whereas CTX-M-15 was the commonest among BTM samples. Additionally, of 52 ESBL-EC isolates from chicken meat samples, 36.5%, 9.6%, and 7.7% harbored the bla(TEM), bla(CMY-2), and bla(SHV-12) genes, respectively, compared with 28.5% of the bla(TEM) and 7.1% of the bla(SHV-12) markers among BTM isolates. The fimH gene was present in 51 isolates of chicken and in 14 isolates of BTM samples, while other virulence genes iutA (n = 31), iroN (n = 26), kpsMT II (n = 5), papC (n = 2), papG allele II (n = 2), papG allele II-III (n = 2), and papEF (n = 2) were only present in chicken meat isolates. Overall, it can be said that contaminated chicken meat and BTM might serve as vehicles for playing potential role in zoonotic transmission of ESBL-EC to humans in Turkey. Practical applications Extended spectrum beta-lactamase producing E. coli (ESBL-EC) have been considered to be one of the major worldwide clinical problems and have been frequently isolated from the foods of animal origins such as chicken meat, fish, and raw milk. The current study aimed to isolate ESBL-EC from chicken and bulk tank milk samples and further characterize the strains by PFGE, identifying resistance genes and as well as virulence genes. Given the high prevalence of CTX-M-15/55 type ESBL-EC strains possessing important virulence genes in chicken and milk samples, it can be said that foods of animal origins might be an important risk factor for extraintestinal ESBL-EC infections for humans.
  • [ N/A ]
    Öğe
    Impact and Diversity of ESBL-Producing Klebsiella pneumoniae Recovered from Raw Chicken Meat Samples in Türkiye
    (Mdpi, 2024) Kuerekci, Cemil; Uenaldi, Oezlem; Sahin, Seyda; Garcia-Menino, Isidro; Hammerl, Jens Andre; Avbersek, Jana
    The interrelationship between human, animal and environmental sectors leads to the spread of antibiotic resistance due to selective pressures, evolutionary traits and genomic evolution. In particular, the frequent use of antibiotics in livestock inevitably influences the emergence of specific resistance determinants in human strains, associated with reduced treatment options in clinical therapy. In this study, ESBL-producing Klebsiella pneumoniae strains isolated from chicken meat samples were evaluated for public health implications in Turkiye. Whole-genome sequencing was used for genetic dissection and phylogenetic comparison of their genomes. The isolates were assigned to four MLST types (ST147, ST37, ST2747 and ST219); two of them were found to represent the ST147 clone associated with severe human infections worldwide. In addition to cephalosporins, high resistance levels to quinolones/fluoroquinolones were identified phenotypically, caused by acquired resistance genes and chromosomal point variations. One isolate was also found to carry the qacE increment 1 efflux transporter gene, which confers tolerance to quaternary ammonium compounds. The detection of virulence genes (i.e., that coding for enterobactin) associated with the pathogenicity of K. pneumoniae suggests a public health impact. Thus, comprehensive information on the occurrence and impact of K. pneumoniae from livestock is needed to derive appropriate management strategies for consumer protection. In this study, it was shown that poultry meat serves as a reservoir of clinically emerging multidrug-resistant high-risk clones.