Antimicrobial resistance of different Acinetobacter baumannii biotypes isolated in the northern region of Chile

Background: Acinetobacter baumannii nonomial outbreaks are common and the microorganism is frequently resistant to multiple antimicrobials. There is little information about Acinetobacter baumannii antimicrobial susceptibility in the northern region of Chile. Aim: To identify different Acinetobacter baumannii biotypes isolated from clinical samples and to determine their antimicrobial susceptibility. Materials and methods: One hundred twenty three Acinetobacter baumannii isolates were studied. The identification and typing of Acinetobacter baumannii was based on phenotypic characteristics. Antimicrobial susceptibility was investigated using agar dilution techniques. Results: Most Acinetobacter baumannii strains were isolated from wounds, urinary and respiratory infections. Seven biotypes were isolates, being biotype 9 the most frequent. Imipenem was the antimicrobial with the higher activity against the microorganism. Amikacin, cefoperazonesulbactam, ampicillinsulbactam and ceftazidime had a moderate activity. There were high resistance levels to ampicillin and older cephalosporins. Conclusions: Acinetobacter baumannii is emerging as a significant nosocomial pathogen in Chile and shows high resistance rates to multiple antibiotics.