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Evolution of an incompatibility group IncA/C plasmid harboring blaCMY-16 and qnrA6 genes and its transfer through three clones of Providencia stuartii during a two-year outbreak in a Tunisian burn unit.
- Source :
-
Antimicrobial agents and chemotherapy [Antimicrob Agents Chemother] 2012 Mar; Vol. 56 (3), pp. 1342-9. Date of Electronic Publication: 2011 Dec 12. - Publication Year :
- 2012
-
Abstract
- During a 2-year period in 2005 and 2006, 64 multidrug-resistant Providencia stuartii isolates, including 58 strains from 58 patients and 6 strains obtained from the same tracheal aspirator, were collected in a burn unit of a Tunisian hospital. They divided into four antibiotypes (ATB1 to ATB4) and three SmaI pulsotypes (PsA to PsC), including 49 strains belonging to clone PsA (48 of ATB1 and 1 of ATB4), 11 strains to clone PsB (7 of ATB2 and 4 of ATB3), and 4 strains to clone PsC (ATB3). All strains, except for the PsA/ATB4 isolate, were highly resistant to broad-spectrum cephalosporins due to the production of the plasmid-mediated CMY-16 β-lactamase. In addition, the 15 strains of ATB2 and ATB3 exhibited decreased quinolone susceptibility associated with QnrA6. Most strains (ATB1 and ATB3) were gentamicin resistant, related to an AAC(6')-Ib' enzyme. All these genes were located on a conjugative plasmid belonging to the incompatibility group IncA/C(2) of 195, 175, or 100 kb. Despite differences in size and in number of resistance determinants, they derived from the same plasmid, as demonstrated by similar profiles in plasmid restriction analysis and strictly homologous sequences of repAIncA/C(2), unusual antibiotic resistance genes (e.g., aphA-6), and their genetic environments. Further investigation suggested that deletions, acquisition of the ISCR1 insertion sequence, and integron cassette mobility accounted for these variations. Thus, this outbreak was due to both the spread of three clonal strains and the dissemination of a single IncA/C(2) plasmid which underwent a remarkable evolution during the epidemic period.
- Subjects :
- Adolescent
Adult
Aged
Bacterial Typing Techniques
Burn Units
Cephalosporins administration & dosage
Child
DNA Restriction Enzymes metabolism
Enterobacteriaceae Infections drug therapy
Enterobacteriaceae Infections microbiology
Female
Gene Transfer, Horizontal
Gentamicins administration & dosage
Humans
Integrons genetics
Male
Middle Aged
Mutagenesis, Insertional
Plasmids
Providencia drug effects
Providencia isolation & purification
Sequence Deletion
Tunisia epidemiology
Anti-Bacterial Agents administration & dosage
Disease Outbreaks
Drug Resistance, Multiple, Bacterial genetics
Enterobacteriaceae Infections epidemiology
Providencia genetics
beta-Lactamases genetics
Subjects
Details
- Language :
- English
- ISSN :
- 1098-6596
- Volume :
- 56
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Antimicrobial agents and chemotherapy
- Publication Type :
- Academic Journal
- Accession number :
- 22155825
- Full Text :
- https://doi.org/10.1128/AAC.05267-11