[Phenotypic characterization of Acinetobacter baumannii isolates in a high-complexity healthcare institution in the city of Cali].

INTRODUCTION: Phenotypic characterization of the Acinetobacter genus bacteria through biochemical and microscopic tests is possible. Studies have shown that the isolates from health-care associated infections show high resistance to first-line antibiotics.

OBJECTIVE: To describe the resistance patterns of the A. baumannii isolates obtained in a health care institution, the phenotypic characteristics of the isolates, and the possible resistance mechanisms.

MATERIALS AND METHODS: A descriptive cross-sectional study was conducted with 28 reports of samples taken from patients hospitalized with infection by A. baumannii . Susceptibility testing for ceftazidime, cefepime, meropenem, amikacin, and ciprofloxacin was performed with the Vitek ™ automated system and the susceptible, intermediate, and resistant classification was based on the protocol established by the Clinical and Laboratory Standards Institute for 2007.

RESULTS: The highest percentage of isolates corresponded to males (53.6 %), to the infectology ward (28.5 %), and to the month of September (21.4 %); the most frequent sample site were endotracheal secretions (53.6 %). From the profile patterns for susceptibility to antibiotics used, 13 phylotypes were obtained.

CONCLUSION: Acinetobacter baumannii is a pathogen resistant to multiple antimicrobial agents involved in outbreaks of health-care associated infections. The resistance profile patterns allow inferring that the possible resistance mechanisms present in the majority of the isolates are: Production of extended-spectrum b -lactamases, antibiotic modifying enzymes, and target site modification.