Korean J Pediatr.  2006 Feb;49(2):150-156. 10.3345/kjp.2006.49.2.150.

Molecular-epidemiologic study on outbreak of colonization by extended spectrum beta-lactamase producing Klebsiella pneumoniae in neonatal intensive care unit

• Jun NL
• Kim MN
• Jeong JS
• Kim YS
• Kim EA
• Kim KS
• Pi SY

• KMID: 1966606
• DOI: http://doi.org/10.3345/kjp.2006.49.2.150

Abstract

PURPOSE: The aims of this study included assessment of molecular-epidemiologic features during an outbreak of colonization of extended spectrum beta-lactamase producing Klebsiella pneumoniae(ESBL-KPN) and re-evaluation of their colonized status one year later.
METHODS
Rectal swab cultures for ESBL-KPN from all hospitalized infants and newly admitted infants were obtained during the outbreak of colonization from July to December, 2000. The pattern of XbaI-digested chromosomal DNA of isolates were analyzed by pulsed-field gel electrophoresis. Weekly rectal swab cultures were obtained during the outbreak until patients were either discharged or decolonized. Patients discharged after being colonized had follow up stool cultures a year later.
RESULTS
A total of 80 patients(28.5 percent) were colonized. Of those, 53 whose pulsed-field gel electrophoresis(PFGE) was possible only once, were ESBL-KPN grouped into six cluster clones and 10 single clones:28 patients(52.8 percent) were colonized with type A, the most common clone, followed by type B in 11 patients(20.8 percent). Of those 12 patients in whom serial PFGE was done more than twice, type A was predominant. Narrowed-down in strains occurred from types A, B, C, D and three single clones at initiation of the study into types A and type B after three months of strict infection control. Among 75 patients(93.7 percent) who were sent home after being colonized, 30 patients were re-called for stool cultures a year later:All of them were decolonized.
CONCLUSION
This study demonstrates the importance of infection control as the diversity of ESBL-KPN strains could be narrowed into fewer strains. Colonization of ESBL-KPN could be reversed upon return to the community.

Keyword

Extended spectrum beta-lactamase producing K. pneumoniae; Pulsed-field-gel-electrophoresis; Colonization; Neonatal intensive care unit

MeSH Terms

beta-Lactamases*
Clone Cells
Colon*
DNA
Electrophoresis, Gel, Pulsed-Field
Follow-Up Studies
Humans
Infant
Infant, Newborn
Infection Control
Intensive Care, Neonatal*
Klebsiella pneumoniae*
Klebsiella*
DNA
beta-Lactamases