[Association of genotype of OXA-carbapenemases of Acinetobacter baumannii and antibiotic resistance].

Objective: To determine the association of the antibiotic resistance of clinical isolates of Acinetobacter baumannii and the genotype of OXA-carbapenemases.

Methods: One hundred and twenty Acinetobacter baumannii strains were isolated from clinical specimens in the West China Hospital from January 2005 to June 2006. The MICs of 12 common antimicrobial agents were determined by 2-fold agar dilution method followed by NCCLS recommendations. The bla(OXA-23) and bla(OXA-24) of those with resistance to IMP were amplified by PCR.

Results: The resistant rates of the 120 isolates to 11 common antimicrobial agents exceeded 50% except for IMP (44.4%). One hundred and ten strains were resistant to more than three common antimicrobial agents, with a resistant rate of 91.67%. Of the 50 strains resistant to IMP, 13 stains carried bla(OXA-23). No bla(OXA-24) was found in the resistant isolates.

Conclusion: Multiple antibiotic resistances are common in Acinetobacters baumannii isolated in the West China Hospital. OXA-23-type carbapenemase is the major carbapenemase that contributes to the nosocomial infection of Acinetobacters baumannii.