Epidemiology and infection control of ESBL-producing Klebsiellapneumoniae strains caused 5 outbreaks in a Hungarian neonatal intensive care unit during the years 2001–2004

Abstract number: 1134_01_32

Damjanova I., Ozsvár Z., Tóth Á., Csanádiné dr. Petró I., Szikra L., Pászti J., Simon G.

Objectives:  

The aim of this study was to perform a prospective survey on prevalence and epidemiological relatedness among ESBL KP strains isolated in a Hungarian NICU during a four-year period.

Methods:  

All patients admitted to NICU during the four-year period were screened for colonisation with ESBL-producing K. pneumoniae. Confirmation of ESBL production was done by Etest, double-disc diffusion and agar dilution methods according to NCCLS. We performed PCR analysis for beta-lactamase detection using specific primers, phage typing, resistance transfer, plasmid profile analysis and plasmid REA, genomic fingerprinting by ERIC-PCR and PFGE to determine the genetic relatedness of strains.

Results:  

Among 210 K. pneumoniae isolates recovered from NICU between 2001–2004, 119 were ESBL-producers, but none of these were isolated in 2004. 107 ESBL isolates were recovered from five outbreak periods. The outbreak strains showed multidrug-resistance with similar antibiotypes. 87 of 107 isolates belonged to six different phage types, but 20 were non typable. PFGE analysis revealed six different genetic clones at 90% similarity level. All isolates harboured plasmids ranging from 2,6 to 203 kb: 14 different plasmid profiles were identified. The same plasmid of 94 kb was obtained from the transconjugants of six outbreak clones by plasmid restriction analysis. The sequence analysis of the SHV PCR products showed that SHV-5 was presented in all outbreak clones and their transconjugants.

Conclusions:  

This prospective study confirms that the same ESBL coding plasmid persisted from 2001–2003 in this hospital ward, while six different outbreak clones were revealed during the given period. After the change of the antibiotic treatment regiment at the beginning of 2004 there were no more ESBL-producers isolated.