DNA fingerprinting and antimicrobial susceptibility pattern of clinical and environmental Acinetobacter baumannii isolates: a multicentre study

Abstract

Background and aim: The aims of this study were to establish antibiotic profile and the molecular epidemiology of Acinetobacter baumannii isolates, with considering the effectiveness of control infection measures across three hospitals in the Kurdistan, west part of Iran.

Methods: Fifty-four A. baumannii isolates were collected from patients and environmental specimens. Antibiotic susceptibility patterns (Antibio-type) were evaluated for 17 different antibiotics and MIC for imipenem was done. Isolates were assessed for the presence of metallo-beta-lactamases (MBLs), class 1 and 2 integrons, and integrated gene cassettes and bla _{OXA-likefamilies} genes. Repetitive-sequence-based PCR (REP-PCR) was done for analysing clonality and relativeness of isolates (REP-type).

Results: Antibiotic susceptibility patterns distinguished 11 distinct Antibio-types and REP-PCR showed three clusters with 20 subclusters, mostly belonged to two clonal subgroups, A1 and B1. bla _OXA-51 and bla _OXA-23 were detected in 100% (54/54) and 52% (28/54), respectively, while bla _OXA-24-like and bla _OXA-58 were not present in isolates. MBLs were not detected, but, however, high rate of imipenem resistance was observed (52%). MIC₉₀ of imipenem was 16 mg/ml. Class 1 integrons were detected in 11% (6/54) of isolates followed by 24% (13/54) of class 2. Both classes of integron genes were detected in 15% (8/54) of isolates. Integrated gene cassettes were in low level (11% of class 1 harboring isolates). Two arrays of gene cassettes were revealed, dfrA5-like and dfrA17-aadA5.

Conclusion: Infection control surveillance should be considered as a serious manner, even the superficial eradication of hospital acquired pathogens. MBL genes were not induced carbapenem resistance in studied hospital settings, but bla _{OXA-51 & 23} contributed in imipenem resistant. Integrons had a little share in resistance of A. baumannii isolates.

Keywords:

• Acinetobacter baumannii
• Carbapenemase
• Integron
• Antimicrobial
• Molecular epidemiology
• REP-PCR