Epidemiology of the Acinetobacter-derived cephalosporinase, carbapenem-hydrolysing oxacillinase and metallo-ß-lactamase genes, and of common insertion sequences, in epidemic clones of Acinetobacter baumannii from Spain.
J Antimicrob Chemother
; 68(3): 550-3, 2013 Mar.
Article
in En
| MEDLINE
| ID: mdl-23143900
ABSTRACT
OBJECTIVES:
To study the distribution, diversity and activity of Acinetobacter-derived cephalosporinase (ADC)-, carbapenem-hydrolysing oxacillinase (CHO)- and metallo-ß-lactamase (MBL)-encoding genes, and of the most common insertion sequences (ISs), in the genome of nosocomial, epidemic, multidrug-resistant Acinetobacter baumannii (MDRAB) clones from Spain.METHODS:
The studied population included 59 MDRAB strains previously genotyped by PFGE and multilocus sequence typing. The search for the ADC (bla(ADC)), CHO (bla(OXA-51-like), bla(OXA-23-like), bla(OXA-40-like) and bla(OXA-58-like)) and MBL (bla(IMP), bla(VIM), bla(SIM-1), bla(GIM-1), bla(SPM-1) and bla(NDM-1)) genes, and for the ISs (ISAba1, ISAba2, ISAba3, ISAba4 and IS18) was done by PCR assays. The phenotypic presence of MBL enzymes was examined using imipenem/imipenemâ+âEDTA strips.RESULTS:
The most prevalent IS, ISAba1 (93.2%), was detected upstream of bla(ADC) and bla(OXA-51-like). These genes showed ample diversity (10 and 8 alleles, respectively). Four ADC sequences (ADC-1-like(P240S), ADC-2-like(N260H/T264N), ADC-11-like(Q163K) and ADC-11-like(G342R)) are described here for the first time. bla(OXA-58-like) was carried by 20.3% of strains, in association with ISAba2, ISAba3 or IS18. bla(OXA-40-like) was the most prevalent acquired CHO gene (57.6%), and was associated with none of the studied ISs. Neither bla(OXA-23-like) nor ISAba4 was detected in any strain. Some 67.8% of strains with MBL activity showed no corresponding gene in PCR; these results were more common in strains with a highly active CHO, such as OXA-40.CONCLUSIONS:
All the studied genes and their related ISs showed a clonal distribution. Imipenem resistance was probably provided by OXA-40 for the most part, while MBL- and OXA-23-encoding genes were absent in the studied population.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Genetic Variation
/
Beta-Lactamases
/
Acinetobacter Infections
/
DNA Transposable Elements
/
Acinetobacter baumannii
Type of study:
Screening_studies
Limits:
Humans
Country/Region as subject:
Europa
Language:
En
Journal:
J Antimicrob Chemother
Year:
2013
Type:
Article
Affiliation country:
Spain