| Autor: |
Chiara Manfreda, Annemarie Kaesbohrer, Silvia Schmoger, Tanja Skladnikiewicz-Ziemer, Mirjam Grobbel, Alexandra Irrgang |
| Jazyk: |
angličtina |
| Rok vydání: |
2024 |
| Předmět: |
|
| Zdroj: |
Microorganisms, Vol 12, Iss 3, p 632 (2024) |
| Druh dokumentu: |
article |
| ISSN: |
2076-2607 |
| DOI: |
10.3390/microorganisms12030632 |
| Popis: |
AmpC beta-lactamases cause resistance to third-generation cephalosporins, including beta-lactamase inhibitors. In Escherichia coli from the German food production chain, the majority of AmpC beta-lactamase activity can be attributed to plasmid-mediated CMY-2 or overproduction of chromosomal AmpC beta-lactamase, but occasionally other enzymes like DHA-1 are involved. This study investigated the prevalence of the AmpC beta-lactamase DHA-1 in ESBL/AmpC-producing E. coli (n = 4706) collected between 2016 and 2021 as part of a German antimicrobial resistance monitoring program along the food chain. Eight isolates (prevalence < 0.2%) were detected and further characterized by PFGE, transformation and conjugation experiments as well as short-read and long-read sequencing. All eight strains harbored blaDHA-1 together with qnrB4, sul1 and mph(A) resistance genes on an IS26 composite transposon on self-transferable IncFII or IncFIA/FIB/II plasmids. During laboratory experiments, activation of the translocatable unit of IS26-bound structures was observed. This was shown by the variability of plasmid sizes in original isolates, transconjugants or transferred plasmids, and correspondingly, duplications of resistance fragments were found in long-read sequencing. This activation could be artificial due to laboratory handling or naturally occurring. Nevertheless, DHA-1 is a rare AmpC beta-lactamase in livestock and food in Germany, and its dissemination will be monitored in the future. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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