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.