Analysis of blaSHV-12-carrying Escherichia coli clones and plasmids from human, animal and food sources.
J Antimicrob Chemother
; 72(6): 1589-1596, 2017 06 01.
Article
en En
| MEDLINE
| ID: mdl-28333184
ABSTRACT
Objectives:
This study aimed at characterizing 23 Escherichia coli isolates from various sources and their respective bla SHV-12 -carrying plasmids and sequencing one of these plasmids completely.Methods:
Isolates were typed by XbaI-PFGE, MLST and PCR-based phylotyping. Transformed bla SHV-12 -carrying plasmids were examined by replicon typing, S1-nuclease, conjugation, EcoRI-HindIII-BamHI digests and plasmid MLST. Co-located resistance genes and integrons as well as the bla SHV-12 genetic environment were analysed by PCR and sequencing. One IncI1 plasmid was sequenced completely using HiSeq 2500 and gap closure by PCRs and Sanger sequencing.Results:
Among the 23 SHV-12-positive E. coli , some isolates from different sources showed the same characteristics ST23/phylogroup A (human, dog, livestock), ST57/D (wild bird, chicken meat) and ST117/D (chicken meat, chicken). All bla SHV-12 genes were horizontally transferable via 30-120 kb plasmids of incompatibility groups IncI1 ( n = 17), IncK ( n = 3), IncF ( n = 1), IncX3 ( n = 1) and a non-typeable plasmid. IncK plasmids, indistinguishable in size and restriction patterns, were found in isolates from different sources (ST57/D, meat; ST131/B2, meat; ST57/B1, dog). The IncI1- bla SHV-12 -carrying plasmids were mostly assigned to plasmid ST (pST) 26 and pST3. Three plasmids showed novel pSTs (pST214, pST215). The majority of the IncI1 transformants exhibited resistance to ß-lactams, chloramphenicol and streptomycin (in relation with a class 1 integron containing an estX - psp - aadA2 - cmlA1 - aadA1 - qacI gene cassette array), and to tetracycline. A novel bla SHV-12 environment was detected and whole plasmid sequencing revealed a Tn 21 -derived- bla SHV12 -ΔTn 1721 resistance complex.Conclusions:
Results from this study suggest that the dissemination of bla SHV-12 genes occurs by vertical (clonal) and horizontal transfer, the latter mainly mediated through IncI1 multidrug-resistance plasmids.
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Banco de datos:
MEDLINE
Asunto principal:
Plásmidos
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Beta-Lactamasas
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Escherichia coli
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Microbiología de Alimentos
Límite:
Animals
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Humans
Idioma:
En
Año:
2017
Tipo del documento:
Article