Mucosal surveillance cultures in predicting Gram-negative late-onset sepsis in neonatal intensive care units.

Summary This study aimed to examine the spectrum and time course of gut and nasopharyngeal colonization with Gram-negative micro-organisms, and to define the value of surveillance cultures in predicting late-onset sepsis in neonates admitted to neonatal intensive care units. Nasopharyngeal and rectal swabs were collected on admission and twice weekly thereafter in 278 neonates admitted within the first 72 h of life with risk factors of early-onset sepsis. Sterile body fluid cultures were obtained on admission and subsequently as clinically indicated. Approximately half of the rectal (693/1250, 55%) and nasopharyngeal (558/1153, 48%) samples but only 6% (32/555) of the sterile fluid samples in 26 patients were culture positive for Gram-negative organisms. In total, 2108 invasive and mucosal culture pairs were analysed. The overall sensitivity, specificity, and positive and negative predictive values of a mucosal sample to predict late-onset sepsis were 27%, 66%, 4% and 94%, respectively. Patients with pre-existing colonization with Klebsiella pneumoniae ( P  = 0.011), Klebsiella oxytoca ( P  = 0.002), Escherichia coli ( P  = 0.003), Stenotrophomonas spp. ( P  = 0.003) and Pseudomonas spp. ( P  ≤ 0.001) were more likely to develop late-onset sepsis. No such association was found for Acinetobacter baumannii , Serratia spp. or Enterobacter cloacae . In conclusion, routine mucosal cultures are inefficient for the prediction of Gram-negative late-onset sepsis in neonatal intensive care units. However, targeted screening for specific organisms in an outbreak (e.g. Klebsiella spp., E .  coli , Stenotrophomonas spp. and Pseudomonas spp.) may offer an opportunity to improve infection control measures and enable timely initiation of appropriate antibiotic therapy.