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

Background: Acinetobacter baumannii nonomial outbreaks are common and the m icroorganism is frequently resistant to multiple antimicrobials. There is l ittle information about Acinetobacter baumannii antimicrobial susceptibilit y in the northern region of Chile. Aim: To identify different Acinetobacter baumannii biotypes isolated from clinical samples and to determine their a ntimicrobial susceptibility. Materials and methods: One hundred twenty thre e Acinetobacter baumannii isolates were studied. The identification and typ ing of Acinetobacter baumannii was based on phenotypic characteristics. Ant imicrobial susceptibility was investigated using agar dilution techniques. Results: Most Acinetobacter baumannii strains were isolated from wounds, ur inary and respiratory infections. Seven biotypes were isolates, being bioty pe 9 the most frequent. Imipenem was the antimicrobial with the higher acti vity against the microorganism. Amikacin, cefoperazonesulbactam, ampicillin sulbactam and ceftazidime had a moderate activity. There were high resistan ce levels to ampicillin and older cephalosporins. Conclusions: Acinetobacte r baumannii is emerging as a significant nosocomial pathogen in Chile and s hows high resistance rates to multiple antibiotics.