Prevalence and molecular characterization of extended-spectrum β-lactamase-producing Klebsiella pneumoniae in Riyadh, Saudi Arabia

Abstract

BACKGROUND AND OBJECTIVES:Reports on extended-spectrum β-lactamases (ESBL) production by Enterobacteriaceae, and especially in Klebsiella pneumoniae, are few in Saudi Arabia. Therefore, we determined the prevalence of ESBL in K pneumoniae from Riyadh and characterized the predominant β-lactamase gene in these isolates.METHODS:A total of 400 K pneumoniae samples were isolated from two hospitals in Riyadh during 2007 and screened for production of ESBL using ESBL-E-strips and combined disk methods. PCR assay was used to detect blaTEM, blaSHV, and blaCTX-M genes.RESULTS:Phenotypic characterization identified a high ESBL rate of 55% of K pneumoniae isolates. ESBL-producing K pneumoniae were PCR positive for SHV, TEM and CTX-M β-lactamase genes with prevalences 97.3%, 84.1% and 34.1%, respectively. Within the CTX-M family, two groups of enzymes, CTX-M-1 and CTX-M-9-like genes were found with prevalences of 60% and 40%, respectively.CONCLUSIONS:This study confirms the high rate of ESBL in K pneumoniae clinical isolates in hospitals in Riyadh. This study demonstrates the worldwide spread of blaCTX-M genes. This first report of the presence of the blaCTX-M gene in clincial isolates in Saudi Arabia is evidence of the continuing worldwide spread of this gene.

Phenotypic and Genotypic Methods for Detection of Extended Spectrum β Lactamase Producing Escherichia coli and Klebsiella pneumoniae Isolated from Ventilator Associated Pneumonia

“…Similar results have been obtained in many studies in India and other countries [7]. In a study conducted from 10 Indian sites in six Indian cities by Welsh et al, [24] bla CTX-M was the most common genotype isolated.…”

“…Similar results have been documented in Europe, Latin America and other countries [25]. The CTX-M genotype, originating from chromosomally encoded enzymes of the Kluyvera spp, has risen in predominance especially in Escherichia coli and Klebsiella pneumoniae they have greater ability to spread and cause outbreaks [7].…”

“…The CTX-M enzyme forms a rapidly growing family of over 69 enzymes currently [7]. This study has been undertaken to identify the occurrence of ESBL among Escherichia coli and Klebsiella pneumoniae from cases of VAP and detect the genes responsible for ESBL production by conventional PCR method.…”

β-Lactamase Production in Key Gram-Negative Pathogen Isolates from the Arabian Peninsula

“…A 2007 study from two hospitals in Riyadh reported that 97.3% of K. pneumoniae isolates carried bla SHV -like genes, followed by 84.1% carrying bla TEM genes and 34.1% carrying bla CTX-M -like genes. Further PCR screening revealed that 60% of the CTX-M-positive isolates carried bla CTX-M-1 -like genes and the other 40% carried bla CTX-M-9 -like genes (16). In April 2005, an outbreak occurring at a neonatal ward in Riyadh was due to an SHV-12-producing K. pneumoniae strain (17) (Table 3), which is prevalent in other parts of the world (18)(19)(20).…”

Prevalence of blaTEM, blaSHV and blaCTX-M among β-lactamase producing Escherichia coli isolated from tertiary care hospitals in Taif, Saudi Arabia

“…[13][14][15][16][17] Rates of 31.7% and 41% have been reported in neighbour Gulf Countries like Kuwait [18] and the United Arab Emirates [19] respectively. In Saudi Arabia, bla TEM , bla SHV and bla CTX-M have been reported in clinical isolates of Enterobacteriaceae in Riyadh [20,21] , Dammam [11] , and Dhahran. [22,23] In the present study, the prevalence of bla TEM , bla SHV and bla CTX-M in E. coli clinical isolates is reported for the first time in Taif governorate.…”