Epidemiological study by pulsed-field gel electrophoresis of an outbreak of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae in a geriatric hospital

Abstract

Twelve cases of infections caused by extended-spectrum beta-lactamase (ESBla)-producing Klebsiella pneumoniae were reported between August 1991 and March 1993 in the Geriatric Department of the Nimes University Hospital, where these bacteria had not been previously isolated. Restriction profiles of total genomic DNAs cleaved byXMal and Spel were compared by pulsed-field gel electrophoresis. The strains that were tested included the 12 isolates from K. pneumoniae-infected patients, strains recovered from rectal swabs of asymptomatic patients in the same ward, and strains isolated in other hospitals in Nimes at the same time. The restriction profiles of the 12 isolates and those recovered from asymptomatic patients in the same ward were very similar. Over a period of more than 1 year, extended-spectrum beta-lactamases were not detected in K. pneumoniae isolates with restriction patterns different from that of the epidemic strain. It seems, therefore, that there was no transfer of a plasmid or a gene coding for ESBla to strains of K. pneumoniae that were different from the epidemic strain. At the same time, ESBla-producing K. pneumoniae isolates exhibiting restriction endonuclease proffles very different from that of the epidemic strain were isolated from other hospitals in Nimes. None of these strains caused an outbreak. Pulsed-field gel electrophoresis, which allows precise characterization of strains beyond the species level, is a useful tool for studying the ESBla-producing K. pneumoniae strains involved in nosocomial outbreaks.

Evolution and epidemiology of extended-spectrum β-lactamases (ESBLs) and ESBL-producing microorganisms

“…It may also be imported by a patient from another center, even though that may be located in another city or country [31,57,[138][139][140][141]. Once selected, the ESBL variant may spread in the center by different means, including clonal dissemination of the producer strain [14,92,93,142,143] or horizontal transmission of the ESBL gene-carrying plasmid among non-related strains [29,144]. A growing number of ESBL outbreaks have recently been attributed to concurrent plasmid transfer and clonal spread events [78,102,134].…”

PCR-based DNA fingerprinting (REP-PCR, AP-PCR) and pulsed-field gel electrophoresis characterization of a nosocomial outbreak caused by imipenem- and meropenem-resistant Acinetobacter baumannii

“…Macrorestriction analysis of chromosomal DNA with SmaI and ApaI (New England Biolabs, Boston, MA, USA) was carried out by PFGE following published procedures [30]. PFGE was run in a CHEF-DRIII apparatus (Bio-Rad Laboratories, Richmond, CA, USA), with pulses ranging from 0.5 to 15 s at a voltage of 6 V/cm at 14 8C for 20 h. Products were detected after staining with ethidium bromide (50 mg/L) and photographed with Polaroid type 665 ®lm.…”

A 5-year epidemiological study of extended-spectrum betabeta-lactamase-producing Klebsiella pneumoniae isolates in a medium- and long-stay neurological unit

“…In these hospitals most of the strains were isolated from patients in short-stay units (intensive care, surgery, general medicine, neonatal medicine and paediatrics) while, in our study, they were isolated from patients in a mediumand long-stay unit. Nevertheless, in the study by Gouby et al (1994), performed in a geriatric unit, the ESBL was also TEM-3.…”

“…pneumoniae producing extended-spectrum b-lactamases (ESBL Kp) were discovered in France in 1984 (Brun-Buisson et al 1987;Sirot et al 1987;Sirot et al 1988;Chanal et al 1989;De Champs et al 1991). Such strains are now encountered world-wide (Casellas and Goldberg 1989;Medeiros 1993;Meyer et al 1993;Pagani et al 1994;French et al 1996;Marranzano et al 1996;Prodinger et al 1996;Grogan et al 1998;Pitout et al 1998;Shannon et al 1998) and are involved in nosocomial outbreaks in intensive care units, cancer, surgery and paediatric departments, medium-and long-stay wards and geri-atric units (Arlet et al 1990;Rice et al 1990;Naumovski et al 1992;Bauerfeind et al 1993;Bingen et al 1993;Gouby et al 1994;Weller et al 1997;Gaillot et al 1998;Peña et al 1998).…”