[Carbapenem-resistant Acinetobacter baumannii causing osteomyelitis and infections of skin and soft tissues in hospitals of Medellín, Colombia].

INTRODUCTION: Acinetobacter baumannii is an opportunistic bacterium which infects seriously ill patients, particularly those with ventilator-associated pneumonia and bacteremia. The emergence of resistance to carbapenem limits the options for the treatment of infections caused by this bacterium.

OBJECTIVE: To describe the clinical and molecular characteristics of infections caused by carbapenem-resistant A. baumannii in Medellín hospitals.

MATERIALS AND METHODS: A cross-sectional descriptive study was carried out in five Medellín hospitals over a 2-year period. Clinical information was obtained from medical histories of patients. The presence of carbapenemases was evaluated by three-dimensional test and PCR. Molecular typing was performed using PFGE and MLST.

RESULTS: The study included 32 patients, 13 of whom presented skin and soft tissue infections (n=7, 21.9%) or osteomyelitis (n=6, 18.7%). Resistance rates of the isolates exceeded 80% for all the antibiotics evaluated except colistin and tigecycline. Carbapenemases OXA-23 and OXA-51, as well as the insertion sequence IS Aba1 , were detected in all the isolates. PFGE revealed high genetic diversity in the isolates and MLST showed clones ST229 and ST758 are circulating in the city.

CONCLUSION: In contrast to previous reports, the results of the present study showed osteomyelitis and infections of skin and soft tissues to be the main infections caused by carbapenem-resistant A. baumannii in Medellín hospitals and revealed its importance as an etiological agent for this type of infections.