Yazar "Hammerl, Jens Andre" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ N/A ]
    Öğe
    Different fosA genes were found on mobile genetic elements in Escherichia coli from wastewaters of hospitals and municipals in Turkey
    (Elsevier, 2022) Guneri, Cansu Onlen; Stingl, Kerstin; Grobbel, Mirjam; Hammerl, Jens Andre; Kurekci, Cemil
    Aims: The increasing number of globally established fosfomycin-resistant (FosR) Gram-negative bacteria inspired us to investigate the occurrence of FosR Enterobacterales populations (esp. E. coli) in samples of city wastewater treatment plants (WWTPs) and hospital sewage in Hatay, Turkey. FosR target bacteria were further characterized for their clonal relatedness, resistomes and mobile genetic elements (MGEs) to evaluate their impact on fosfomycin resistance dissemination. Methods: A total of 44 samples from raw and treated waters of WWTPs as well as of two hospitals in the Hatay province were subjected to selective cultivation for recovering FosR Enterobacterales. The presence of fosA was verified by PCR and Sanger amplicon sequencing. Detected E. coli were further evaluated against antimicrobial susceptibility-testing, macrorestriction profiling (PFGE) and whole-genome sequencing (WGS). Bioinformatics analysis was performed for genome subtyping (i.e., MLST, serotype), resistome/virulome determination and dissection of the genetic determinants of plasmidic fosA3/4 resistances. Results: Besides ten non-E. coli Enterobacterales, 29 E. coli were collected within this study. In silico-based subtyping revealed that E. coli isolates were assigned to six different serovars and 14 sequence types (ST), while O8:H21 and ST410 represented the major prevalent types, respectively. Fosfomycin resistance in the isolates was found to be mediated by the fosA4 (n = 18), fosA3 (n = 10) and fosA (n = 1), which are frequently associated with transmissible MGEs. Reconstruction of plasmid-associated fosA gene context revealed a linkage between the resistance cassette and IS6 (IS26 family) transposases, which might represent a major driver for the distribution of the genes and the generation of novel fosA-carrying plasmids. Conclusions: The occurrence of plasmid-mediated, transmissible FosR in E. coli from wastewater pose a foreseeable threat to One-Health. To minimize further spread of the resistances in bacterial populations associated with environmental, animal and human health further resistance monitoring and management strategies must be developed.
  • [ 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.