ABSTRACT Background: Carbapenem-resistant Acinetobacter baumannii (CRAb) is an important cause of nosocomial infections especially in intensive care units. This study aimed to assess clinical aspects and the genetic background of CRAb among ICU patients at a Brazilian teaching hospital. Methods: 56 critically ill patients colonized or infected by CRAb, during ICU stay, were prospectively assessed. Based on imipenem MIC ≥ 4 µg/mL, 28 CRAB strains were screened for the presence of genes encoding metallo-β-lactamases and OXA-type β-lactamases. The blaOXA-type genes were characterized by PCR using primers targeting ISAba-1 or -3. Genetic diversity of blaOXA-positive strains was determined by ERIC-PCR analysis. Results: Patient's mean age (±SD) was 61 (±15.1), and 58.9% were male. Eighty-percent of the patients presented risk factors for CRAb colonization, mainly invasive devices (87.5%) and previous antibiotic therapy (77.6%). Thirty-three patients died during hospital stay (59.0%). Resistance to carbapenems was associated with a high prevalence of blaOXA-23 (51.2%) and/or blaOXA-143 (18.6%) genes. ERIC-PCR genotyping identified 10 clusters among OXA-producing CRAb. Three CRAb strains exhibited additional resistance to polymyxin B (MIC ≥ 4 µg/mL), whereas 10 CRAb strains showed tigecycline MICs > 2 µg/mL. Conclusions: In this study, clonally unrelated OXA-123- and OXA-143-producing A. baumannii strains in ICU patients were strongly correlated to colonization with infected patients being associated with a poor outcome.

In order to prevent and control the spreading of infectious and contagious diseases and multi-resistant bacteria in hospital settings, measures are adopted beyond the standard measures, according to the means of transmission. This study monitored patients and defined behaviors for the prevention and control in a pediatric ward of a teaching hospital from January to April 2004. All patients were monitored for infectious-contagious diseases or colonization by multiresistant bacteria. Eighty-six patients were indicated for precautions, of which 93% due to possible or confirmed multiresistant bacteria, with, respectively, 5 and 27 days average stay. Only 6 patients had infectious-contagious diseases. The results showed an increase in the number of patients with multiresistant bacteria, with a predominance of gram-negative bacteria. This shows the need for educational measures for health workers, children, parents and visitors with a clear definition of their responsibilities in the healthcare process.

Para prevenir y controlar la transmisión de enfermedades infecciosas y de bacterias resistentes en el ambiente hospitalario se adoptan precauciones de acuerdo con las vías de transmisión, además de las precauciones estándar. Este estudio se propuso monitorear los pacientes y definir los tipos de precauciones de acuerdo con la(s) vía(s) de transmisión de las bacterias resistentes y enfermedades infectocontagiosas en una unidad pediátrica de un hospital escuela, entre enero y abril de 2004. Fueron monitoreados todos los pacientes con diagnostico de enfermedad infectocontagiosa y/ o bacteria resistente. Ciento ochenta y siete pacientes (27,5%) tuvieron indicación de precauciones, 95,8% de ellos por sospecha o confirmación de ser portadores de bacterias resistentes. La precaución por contacto fue la más indicada. Sólo para seis pacientes hubo indicación como para enfermedad infectocontagiosa. Los resultados evidenciaron aumento de portadores de bacterias resistentes, sobre todo de Gram negativas.

Para prevenir e controlar a disseminação de doenças infecto-contagiosas e bactérias resistentes no ambiente hospitalar adotam-se precauções de acordo com as vias de transmissão, além das precauções-padrão. Com este estudo, objetivou-se monitorar os pacientes e definir as condutas pertinentes à prevenção e controle da transmissão das doenças infecto-contagiosas e bactérias resistentes em uma unidade pediátrica de um hospital de ensino, no período de janeiro a abril de 2004. Foram monitorados todos os pacientes internados quanto ao diagnóstico de doenças infecto-contagiosas ou colonizados por bactéria resistente. Dentre os pacientes, 87 (27,5%) tiveram indicação de precauções de acordo com as vias de transmissão, sendo 95,8% deles por suspeita ou confirmação de serem portadores de bactérias resistentes. A precaução por contato foi a mais indicada. Apenas para seis pacientes a indicação deveu-se a doenças infecto-contagiosas. Os resultados evidenciaram aumento de portadores de bactérias resistentes, predominantemente gram-negativos.