Study of multi-drug resistant microorganisms isolated from blood cultures of hospitalized newborns in Rio de Janeiro city, Brazil

RESUMO

The aims of this study were to determine the frequency and antimicrobial resistance patterns of microorganisms associated with sepsis cases in a public maternity hospital, and to analyze the main demographic data relating to these infected neonates over a two year period. We analyzed 255 positive blood cultures and the medical records of newborns admitted to the neonatal intensive care unit of the Hospital Maternidade Alexander Fleming II, Rio de Janeiro city, Brazil, from July 1997 to July 1999. Identification and antibiograms of the isolated strains were performed according to routine laboratory procedures. Demographics and microbiological data were analyzed using the Epi-Info program. The mean age of the newborns was 13.1 days, with an average of 1.2 strains isolated per patient. Antibiotics were administered to 207 83.1(per cent) patients before positive blood culture presentation. A total of 90.8 (per cent) patients were premature; 83.9 (per cent) had a gestational age of less than 36 weeks; 52.6 (per cent) presented very low birth weight; 39.8 (per cent) had asphyxia and 33.3 (per cent) presented hyaline membrane disease. A total of 301 microorganisms were isolated with a predominance of Klebsiella pneumoniae 22.9 (per cent), coagulase-negative Staphylococci 17.3 (per cent), Serratia marcescens 15.9 (per cent) and Pseudomonas aeruginosa 10.6 (per cent). Gram-negative strains showed high resistance levels to cephalosporins and aminoglycosides. A total of 93.3 (per cent) Staphylococcus aureus strains were methicillin-resistant. The newborns examined in this study presented several risk factors for acquiring hospital infection and the isolated microorganisms showed high levels of resistance to the majority of the antibiotics routinely used in the hospital.