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Published on: February 1, 2018
Neonatal intestinal colonization with extended-spectrum β-lactamase-producing Enterobacteriaceae-a 5-year follow-up
V Nordberg1, K Jonsson2, C G Giske3
1Department of Neonatal Medicine, Karolinska University Hospital, Sweden; Department of Clinical Science, Intervention and Technology (CLINTEC), Division of Paediatrics, Karolinska Institutet, Sweden.
Insights
Extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae (KP) and Escherichia coli (EC) colonization in neonates can persist for years. Two years post-discharge, nearly a quarter of infants remained carriers, with one ESBL-EC case at age five.
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.
Objectives:
To analyse Klebsiella pneumoniae (KP) isolates from an outbreak of extended-spectrum β-lactamase (ESBL)-producing KP and Escherichia coli (EC) among infants admitted to neonatal intensive care units and to determine the duration of the intestinal colonization.
Methods:
We performed a prospective cohort study of intestinal ESBL-KP/ESBL-EC colonized neonates after a 5-month outbreak in two neonatal intensive care units. Whole genome sequencing, multilocus sequence typing, core genome multilocus sequence typing, pulsed-field electrophoresis and PCR for blaCTX-M were performed on the first isolates. Stool cultures were performed every second month after discharge until 2 years after discharge and at 5 years of age. The last positive samples were analysed with pulsed-field gel electrophoresis and PCR for blaCTX-M. The intestinal relative dominance of ESBL-producing Enterobacteriaceae was determined.
Results:
Thirteen of 17 patients colonized with ESBL-KP/ESBL-EC survived. Isolates from 16 of 17 patients were available for analysis and featured the same strain type of ESBL-KP: sequence type 101. The strain had capsule type K29 and harboured blaCTX-M-15. The virulence genes irp1, irp2, iutA, kfu and mrk were detected in all isolates. The median length of colonization was 12.5 months (range, 5-68 months). After 2 years, two of 13 patients were carriers of ESBL-KP and one of 13 of ESBL-EC. At 5 years of age, one neonate was colonized with ESBL-EC. No infant experienced an ESBL-KP/EC-infection during follow-up.
Conclusions:
Two years after discharge, almost one fourth of the study participants were ESBL/KP-EC carriers. ESBL-KP sequence type 101 persisted in two of 13 children for 23 to 26 months. One patient was colonized with ESBL-EC at age 5 years.
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