Microorganisms identified in neonatal sepsis and their antimicrobial resistance in a hospital in Western Mexico

Background: Neonatal sepsis is a serious condition that increases neonatal mortality.The objective of this study was to describe the microorganisms causing neonatal sepsis and their resistance patterns in a neonatal intensive care unit (NICU).Methods: A cross-sectional cohort study was conducted.Microorganisms identified in blood or cerebrospinal fluid cultures from newborns (NBs) admitted to the Nuevo Hospital Civil de Guadalajara Dr. Juan I. Menchaca were studied.Microorganism identification and susceptibility testing were performed using VITEK 2. The cutoff points for classifying resistance were according to the Clinical and Laboratory Standards Institute.Infections were classified as early-onset sepsis (EOS) or late-onset sepsis (LOS).Results: A total of 73 NBs with EOS and 261 with LOS were identified; the incidence rate of EOS was 7.1 events/1000 live births and of LOS was 25.5 events/1000 live births.In both infections, the risk was significantly higher in premature NBs and/or NBs with birth weight < 2500 g.The predominant etiology in all infections was Enterobacterales (63.3%).In EOS, resistance to first-line antibiotics for Enterobacterales was ampicillin 46.6% (27/58) and gentamicin 24.1% (14/58), while in LOS, it was ampicillin 63.7% (186/292) and gentamicin 28.1% (82/292).The second most frequently identified bacteria were Staphylococcus spp.13.6% (n = 75) with oxacillin resistance of 78.7% (59/75).No ampicillin-resistant Streptococcus spp. or Enterococcus spp. was identified.Conclusions: The incidence of EOS and LOS in a Mexican NICU was 7.1 and 25.5 events/1000 live births, and the main etiologies were Enterobacterales and Staphylococcus spp.