Bacterial isolates of early-onset neonatal sepsis and their antibiotic susceptibility pattern between 1998 and 2004: an audit from a center in India

BACKGROUND: Epidemiology and surveillance of neonatal sepsis helps in implementation of rational empirical antibiotic strategy. OBJECTIVE: To study the frequency of bacterial isolates of early onset neonatal sepsis (EONS) and their sensitivity pattern. METHODS: In this retrospective study, a case of EONS was defined as an infant who had clinical signs or born to mothers with potential risk factors for infection, in whom blood culture obtained within 72 hours of life, grew a bacterial pathogen. Blood culture sample included a single sample from peripheral vein or artery. Relevant data was obtained from the unit register or neonatal case records. RESULTS: Of 2182 neonates screened, there were 389 (17.8%) positive blood cultures. After excluding coagulase-negative Staphylococci (160), we identified 229 EONS cases. Preterm neonates were 40.6% and small for gestational age, 18.3%. Mean birth weight and male to female ratio were 2344.5 (696.9) g and 1.16:1 respectively. Gram negative species represented 90.8% of culture isolates. Pseudomonas (33.2%) and Klebsiella (31.4%) were common among them. Other pathogens included Acinetobacter (14.4%), Staphylococcus aureus (9.2%), E.coli (4.4%), Enterobacter (2.2%), Citrobacter (3.1%) and Enterococci (2.2%). In Gram negative group, best susceptibility was to Amikacin (74.5%), followed by other aminoglycosides, ciprofloxacin and cefotaxime. The susceptibility was remarkably low to ampicillin (8.4%). Gram positive group had susceptibility of 42.9% to erythromycin, 47.6% to ciprofloxacin and above 50% to aminoglycosides. Of all isolates, 83.8% were susceptible to either cefotaxime or amikacin CONCLUSION: Gram-negative species especially Pseudomonas and Klebsiella were the predominant causative organisms. Initial empirical choice of cefotaxime in combination with amikacin appeared to be rational choice for a given cohort.