Neonatal intestinal colonization with extended-spectrum β-lactamase-producing Enterobacteriaceae-a 5-year follow-up...

Area of Science:

• Medical Microbiology
• Infectious Diseases
• Neonatal Care

Background:

• Neonatal intensive care units (NICUs) are vulnerable settings for outbreaks of multidrug-resistant organisms.
• Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae pose a significant threat to vulnerable infant populations.

Purpose of the Study:

• To analyze Klebsiella pneumoniae (KP) and Escherichia coli (EC) isolates from an ESBL-producing outbreak in NICU infants.
• To determine the duration of intestinal colonization by ESBL-producing KP and EC in neonates.

Main Methods:

• Prospective cohort study of neonates colonized with ESBL-KP/ESBL-EC following an NICU outbreak.
• Whole genome sequencing, multilocus sequence typing, and PFGE for isolate characterization.
• Stool cultures conducted bi-monthly post-discharge for up to 2 years, and at 5 years of age.

Main Results:

• The predominant ESBL-KP strain identified was sequence type 101, harboring blaCTX-M-15 and specific virulence genes.
• Median colonization duration was 12.5 months, with persistence up to 68 months in some cases.
• Two years after discharge, 23% of patients were carriers of ESBL-KP or ESBL-EC; one patient remained colonized with ESBL-EC at age 5.

Conclusions:

• A significant proportion of neonates remain colonized with ESBL-producing Enterobacteriaceae long after NICU discharge.
• The ESBL-KP ST101 strain demonstrated remarkable persistence in some children for over two years.
• Long-term intestinal colonization highlights the need for ongoing surveillance and infection control measures in neonatal populations.