prevalence of anaerobic and aerobic bacteria in early onset neonatal sepsis

background: to determine prospectively the prevalence of anaerobic and aerobic infection in early onset (during 72 hours of age) neonatal sepsis, in tehran vali-e-asr hospital. methods: among all the live birth, neonates suspecting of having septicemia were investigated for isolation of micro­organisms. culture bottle containing enriched tryptic soy broth was used for standard blood culture system to detect aerobes and an anaerobic/f bottle was inoculated using bactec 9120 continuous monitoring blood culture system to deter­mine the growth of anaerobic bacteria. among 1724 live births, 402 consecutive neonates suspecting of having septicemia were investigated for isolation of micro organism. results: a total of 27 episodes of early onset neonatal sepsis occurred with an incidence of 15.66 (11.6 aerobe + 4.0 anaer­obe) per 1000 live births. aerobic bacteria were the major etiological agents, accounting for 20 cases. 7 (26%) cases had posi­tive blood cultures with anaerobic bacteria. propionibacterium and peptostreptococccus (amongst anaerobic) and coagu­lase-negative staphylococci and staphylococcus aureus (amongst aerobic) were the most commonly isolated organisms. compari­son of clinical findings and demographic characteristics between aerobic and anaerobic infection did not have a signifi­cant statistical difference. conclusion: our impression is that while anaerobic bacteremia in the newborn infants can occasionally cause severe morbid­ity and mortality, majority of cases experience a self limited illness with transient bacteremia.