Analysis of late-onset neonatal sepsis cases in a level three neonatal intensive care unit

Newborns in neonatal intensive care units (NICUs) are at high risk for developing nosocomial infections (NIs), which may result in morbidity and mortality. In this study, we aimed to ascertain the bacteriological profiles and their antimicrobial susceptibility patterns in NIs.

We conducted a cross-sectional study in the NICU. Late-onset sepsis (LOS) cases confirmed with blood cultures were evaluated retrospectively. Laboratory parameters, demographics, and clinical data were collected and analyzed from hospital records retrospectively.

Of the 1210 infants in the NICU, 76 (6.3%) had LOS. A total of 86 episodes of LOS were documented; in 10 infants, two pathogens were identified. The mean gestational age (GA) of the infants with LOS was 33.2±4.8 weeks (23 to 42 weeks). Gram-positive cocci (GPC) caused most of the LOS episodes (65.8%, 50/76), with coagulase-negative Staphylococcus (CoNS) as the most common cause of LOS (50%, 38/76). Gram-negative rod species (GNRs) accounted for 32.9% (25/76) of the LOS cases, and fungi accounted for 1.3% (1/76). The mortality rates for GNR and GPC were 17.9% and 6.4%, respectively (p>0.05). The mean CRP and conjugated bilirubin levels for the GPC and GNR groups were 37.5 vs. 29.5 mg/dl and 0.7 vs 1.5 mg/dl, respectively (p>0.05). GNRs had a 20-25% ceftriaxone resistance. Two (4%) GPC species were resistant to linezolid, while all were susceptible to vancomycin. All of the GNRs were susceptible to carbapenems.

These results underscore the recent emergence of CoNS in NICUs. LOS due to GNRs seems to display higher C-reactive protein and conjugated bilirubin values than those due to GPC. Clinical monitoring of NIs and bacterial resistance profiles are required in all NICUs.