Neonatal bacteremia in a neonatal intensive care unit: analysis of causative organisms and antimicrobial susceptibility.

BACKGROUND Infections cause significant mortality and morbidity in neonates, especially the premature ones. Although there are various antibiotics can be used to combat neonatal infection, resistant strains have subsequently emerged. In an epidemiological survey, we analyzed bacterial isolates and their antibiotic susceptibilities for cases of bacteremia in a neonatal intensive care unit (NICU) of a teaching hospital. METHODS From November 1999 to October 2001, 623 neonates admitted to the NICU were enrolled. The incidence and incidence density of bacteremia, morbidity and mortality of sepsis, as well as antibiotic susceptibility, were investigated. RESULTS Totally, 754 blood cultures were done on 623 patients. Fifty-eight patients experienced 85 episodes of bacteremia, with 87 isolates cultured. The incidence of bacteremia in our NICU was 9.31% (58/623) with an incidence density of 10.98/1000 patient-days. The overall mortality rate was 7.22%. The case fatality rate of bacteremia was 20.7% (12/58). The bacterial pathogens encountered, in order of frequency, were coagulase-negative Staphylococcus (29%), Staphylococcus aureus (22%), and Enterobacter cloacae (17%). All of the gram-positive bacteria were susceptible to vancomycin, while the gram-negative bacteria were susceptible to imipenem, amikacin and ciprofloxacin. Oxacillin-resistant S. epidermidis, oxacillin-resistant S. aureus, and multi-drug resistant enterobacteriae were the leading microorganisms causing bacteremia in our NICU. CONCLUSIONS It is an endless struggle to combat neonatal infection. Periodic evaluation of bacterial antibiotic susceptibility is necessary. More judicious selection of antibiotics and rotating antibiotic regimens should be kept in mind to reduce the resurgence of multidrug resistant strains.