High prevalence of CTX-M-15 extended spectrum beta-lactamase-producing bacterial clinical isolates in both community and hospital settings in Egypt

ABSTRACT

High prevalence of infections caused by extended-spectrum beta-lactamase [ESBL]-producing isolates, notably Escherichia coli, has been suggested in Egypt. As little is known about the genetic background of these isolates, ESBL-positive E. coli isolates obtained among 520 Enterobacteriaceae prospectively collected [May 2007 -August 2008] from inpatients [n=320] and outpatients [n=200] seen at the Theodor Bilharz Research Institute [Cairo], were characterized. Clinical epidemiology, antibiotic susceptibility, and genetic traits including bla gene, phylogenetic group, ERIC-2 PCR profile, multilocus sequence type [ST] were determined. Among the 520 collected Enterobacteriaceae, were 291 [56%] E. coli and 165 [32%] Klebsiella pneumoniae. A total of 16% of all Enterobacteriaceae were ESBL-producers 19% in E. coli and 14% in K. pneumoniae. Of the E. coli ESBL-producers, 75% [n=41] were isolated from urine. Rates of ESBL producers did not differ significantly between in and outpatients for E. coli [20 vs 17%] but significantly for non E. coli ESBL producers [18.5 vs 1.2 % p= 0.0001]. CTX-M-15 was identified in all ESBL producers. Of the E. coli ESBL producers, 40% belonged to phylogenetic group A, 32% to D and 26% to B2. The ERIC-2 PCR method showed genetic background diversity with clusters in each group having profiles indistinguishable to that of previously published clones complex ST10 and ST131. MLST showed that 75% of E. coli group B2 belonged to clone ST131 and 15% to clones previously detected worldwide, ST73 and ST405. This study illustrates the dissemination of different E. coli clones producing CTX-M-15 in Africa, notably in outpatients