Nosocomial infections caused by klebsiellae species with plasmids carrying bla shv-5 extended-spectrum beta-lactamase gene in Mansoura university hospitals

ABSTRACT

SHV-5 is a variant of SHV-1 and it is considered now one of the most important ESBL enzymes produced by Klebsiellae species. In this study we aimed to detect the prevalence of plasmid encoded SHV-5 among Klebsiellae strains causing nosocomial infections in Mansoura University Hospitals [MUH]. One hundred and seventy four Klebsiellae strains were isolated from overall 680 cases of nosocomial infections [25.59%] acquired within MUH over 4 months period from July to November 2004. One hundred and thirty six isolates [78.16%] of them were K. pneumoniae and 38 isolates [21.84%] were K. oxytoca. MICs [micro g/ml] of the isolated strains was done for augmentin, cefoperazone and ceftazidime using E test. One hundred and forty one [81.03%] of them were beta- lactamase producer as detected by nitrocefin discs, where 77 isolates from ?-lactamase producing strains were ESBL producers constituting 44.25% of Klebsiellae isolates. Sixty six ESBL producing strains of total 77 were isolated from cases of blood stream infections [85.71%]. Sixty five ESBL producing strains were isolated from neonatal intensive care unit [NICU] [84.42%]. All ESBL producing strains [n=77] posses at least one large plasmid > 23 kbp. SHV-5 gene was amplified by PCR after plasmid isolation from ESBL producing Klebsiellae isolates, reveal that 68 isolates [88.31%] were harbored SHV-5 gene on their large plasmids. In conclusion we found that the SHV-5-producing K. pneumoniae isolates were recovered from different wards of Mansoura University Hospital during the studied period. Thus, it was hypothesized that one clone may have persisted in that hospital. We recommend that infection control measure of endemic ESBL producers should include the consumption of the broad-spectrum cephalosporins needs to be restricted to reduce the selection pressure which enables the proliferation of ESBL producers in hospital, continuous application of infection control program as; surveillance, hand washing and contact isolation procedure