High Prevalence and Antimicrobial Drug Susceptibility of Multidrug Resistant Acinetobacter baumannii

Keimyung Medical Journal 2012;31(1):83-93.

다약제 내성 Acinetobacter baumannii 의 유병율과 항균제 감수성

서성일; 백원기; 서민호

Abstract

Acinetobacter baumannii is a typical nosocomial pathogen causing infections and high mortality; almost exclusively in compromised hospital patients. Multidrug resistant Acinetobacter baumannii (MDRAB) is currently causing one of the most difficult infections to treat; because efficacious antimicrobial choices have been highly limited. A total of 176 strains of Acinetobacter baumannii isolated from various clinical specimens in a university medical center were tested for antimicrobial drug susceptibility to 24 drugs including imipenem; meropenem; levofloxacin; colistin and minocycline. Acinetobacter baumannii were most frequently isolated from sputum (84.1%); followed by wound discharge (8.0%); urine (2.8%); pus (2.3%) and etc. Most of the strains were resistant to all the ß-lactams tested; imipenem; meropenem; aztreonam; gentamicin; netilmicin; fluoroquinolones and trimethoprim-sulfamethoxazole. MIC90 of these drugs were more than 512 ㎍/mL; except carbapenems (MIC90: 128-256 ㎍/mL). The resistance frequencies of amikacin and tobramycin were 63.1% and 60.8%; respectively (MIC90: more than 512 ㎍/mL). Most of the strains were susceptible to colistin and minocycline; and MIC90 was 1 and 4 ㎍/mL; respectively. The resistance frequency of doxycycline was 10.8% (MIC90: 32㎍/mL). Isolation frequency of MDRAB strains was 97.7% (172 strains) and was highly prevalent. Fifty eight (33.0%) strains were multiply resistant to 20 drugs; and twenty eight (15.9%) strains were multiply resistant to 19 drugs. All of the MDRAB were multiply resistant to more than 16 drugs. We need concerted multidisciplinary efforts to preserve the efficacy of currently available antimicrobial agents; by continued surveillance of MDRAB prevalence and antimicrobial resistance patterns that is important to choose effective drugs for MDRAB infections.

Key Words: Antimicrobial susceptibility, Colistin, Minocycline, Doxycycline, Imipenem, Levofloxacin, Multidrug resistant Acinetobacter baumannii (MDRAB)