Nosocomial bloodstream infections: organisms, risk factors and resistant phenotypes in the Brazilian University Hospital.

Bacteremia is one of the most frequent and challenging hospital-acquired infection and it is associated with high attributable morbidity and mortality and additional use of healthcare resources. The objective of this work was to determine the frequencies of its occurrence, organisms and resistance phenotypes associated to nosocomial acquired bloodstream infections. A total number of 51 nosocomial bacteremia by Gram-negative and 99 by Gram-positive were evaluated and compared during a 15-month period. The risk factors associated with these bacteremias were analyzed and antibiotic use and surgery were associated with bacteremia by Gram-negative and > 2 invasive devices with Gram-positive. The resistance phenotypes ESBL (extended-spectrum beta-lactamases) (23.5%) and AmpC/others (17.6%) correspond to 41.2 % with predominance of E. agglomerans among AmpC (44.4%) and K. pneumoniae among ESBLs (38.5%). Among S. aureus bacteremia, approximately 40% were associated to MRSA (methicillin-resistant Staphylococcus aureus).