Neonatal Intestinal Colonization with Extended-Spectrum B-Lactamase-Producing Enterobacteriaceae: Molecular Analysis and Risk Factors in NICU neonates

The goal of this project was to assay the prevalence of fecal carriage of ESΒL-producing Enterobacteriaceae (ESΒL-PE), and to identify the risk factors for carriage in neonates hospitalized in a Neonatal Intensive Care Unit (NICU) of an educational therapeutic hospital (Vali-e-Asr) of Birjand city, east of Iran.

Rectal swabs were taken from 200 neonates at the beginning of hospitalization, every week in case of hospitalization and at the time of discharge. Bacterial isolates were identified using different biochemical experiments. Screening of ESΒL-PE was first done by phenotypic test (DD test) and then antibiotic resistance genes were detected by PCR assay.

In our research, 42 Enterobacteriaceae were obtained from 200 neonates. The total prevalence rate of neonatal rectal carriage of ESΒL-PE was 42/200 (21%), mostly Escherichia coli, 18 (42.8%). blaCTX-M and blaCTX-M-15 were the most prevailing β-lactamase-encoding genes recognized by PCR tests. Intestinal carriage of ESβL among neonates displayed a statistically significant relationship with the use of the mechanical ventilation (p=0.025), APGAR score (p=0.005) and gestational age (weeks) (p=0.044).

Our findings highlighted the importance of consistent screening for resistant ESΒL-PE among neonates (especially preterm newborns) and minimizing invasive ventilation whenever possible.