Neonatal sepsis contributes a significant rate in infants mortality and morbidity. The pathogens are diverse from region to another and change time to time even in the same place. To evaluate the incidence of neonatal sepsis, the causative microbial pattern of neonatal sepsis, and the susceptibility of antibiotics at one of referral center hospital in Indonesia, Haji Adam Malik Hospital, a cross-sectional descriptive study was conducted on neonates with sepsis diagnosis proven with positive blood culture within one year period (2015-2016). Among 626 neonates admitted to perinatology unit, the total of 154 neonates were having proven neonatal sepsis with positive blood culture with the incidence rate 24.6%. 79 (51.3%) neonates were diagnosed with early onset sepsis while 75 (48,7%) neonates had late onset sepsis. Klebsiella pneumonia was the most common isolated organism in both early and late onset sepsis, encompassing 19.5% of cases. K. pneumonia is resistant to ampicillin, third generation cephalosporins (cefotaxime, ceftriaxone, ceftazidime) and aminoglycoside (gentamicin). Among 30 cases of K. pneumonia infection, 8 cases also showed resistance to meropenem. Regular periodic surveillance of the causative organisms of neonatal sepsis is needed to implement the rational empirical choice of antibiotic prescription while waiting blood culture result come out.

Keywords: Neonatal Sepsis, Microbial pattern, Early onset sepsis, Late onset sepsis, Antibiotic sensitivity.