Publikationsdatenbank

Occurrence and characterisation of ESBL-encoding plasmids among Escherichia coli isolates from fresh vegetables (2018)

Art

Zeitschriftenartikel / wissenschaftlicher Beitrag

Autoren

Freitag, Christin (WE 7)

Michael, G B (WE 7)

Li, Jun

Kadlec, Kristina

Wang, Yang

Hassel, Melanie

Schwarz, Stefan (WE 7)

Quelle

Veterinary microbiology : an international journal

Bandzählung: 219

Seiten: 63 – 69

ISSN: 0378-1135

Sprache

Englisch

Verweise

DOI: 10.1016/j.vetmic.2018.03.028

Pubmed: 29778206

Kontakt

Institut für Mikrobiologie und Tierseuchen

Robert-von-Ostertag-Str. 7-13
14163 Berlin
+49 30 838 51843 / 66949
mikrobiologie@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates have been increasingly reported in different reservoirs. The aims of this study were to investigate the presence of ESBL-producing E. coli in fresh vegetables and to characterise their ESBL gene-carrying plasmids. Among the 245 samples from vegetables investigated during 2011-2013, seven putative ESBL-producing E. coli (salad n = 2, sprouts n = 5) were found. They were subjected to ESBL phenotypic confirmatory tests, detection/sequencing of ESBL genes, antimicrobial susceptibility testing (AST), phylotyping, XbaI-macrorestriction analysis, multilocus sequence typing and transformation. Transformants were characterised by AST, S1-nuclease PFGE, replicon typing, conjugation and investigated for co-located antimicrobial resistance genes. Two ESBL gene-carrying plasmids were sequenced using a HiSeq 2500 system. The seven isolates were confirmed as ESBL producers, displayed unrelated XbaI-patterns and unique sequence types (STs) and belonged to the phylogroups A, B1 or D. The ESBL genes were located on plasmids. Two plasmids carrying bla_CTX-M-14 genes (incompatibility group IncK or IncHI2) were seen in isolates from salad (ST973) and sprout (ST527). Two bla_CTX-M-15- (IncFIB; non-typeable) and the IncN bla_CTX-M-65- and IncHI2 bla_CTX-M-125-carrying plasmids were found in isolates from sprouts (ST410, ST847, ST10, ST542). All plasmids were conjugative, except for the IncFIA-FIB bla_CTX-M-2-carrying plasmid. Sequence analysis of two plasmids identified the ESBL genes in close location to other resistance genes: sulfonamide resistance gene sul2, streptomycin resistance genes strA and strB, the plasmid-mediated quinolone resistance gene qnrS1 and bla_TEM-1 (sul2-strA-strB-IS66-bla_TEM-1-tnpR-ΔtnpA-ISEcp1-bla_CTX-M-15-Δorf477-ΔtnpA-qnrS1) or the fosfomycin resistance gene fosA3 (ΔISEcp1-bla_CTX-M-125-ΔIS903B-fosA3). These observations underline the importance of vegetables as reservoirs for multidrug resistant ESBL-producing E. coli.