Phenotypic and Genotypic Detection of Extended-Spectrum β-Lactamases (ESBL) among Escherichia coli Isolated from Symptomatic Female's Genital Tract Infection

Abstract

Clinical E. coli isolates (36) from women (aged 18-45 years) with symptomatic genital tract infection were detected phenotypically and genotypically for ESBL production. Phenotypically, most (30/36: 83.3%) isolates were resistant to cefotaxime (CTX) and more than half of them (26/36: 72.2%) were resistant to ceftazidime (CAZ). All (100%) and 25 (69.4%) of them were ESBLs producers by screening and confirmatory tests, respectively. Genotypically, ESBL genotypes were detected in 31/36 (86.1%) of isolates. All four ESBL genotypes were found among these isolates with predominance of CTX-M-type (26/36: 72.2%) followed by SHV-type (22/36: 61.1%), OXA-type (7/36: 19.4%), and TEM-type (1/36: 2.7%). Of These isolates, 25/36 (69.4%) had two types of ESBL genes. Seventeen (17/22: 77.2%) of SHV-type positive isolates were CTX-M positive. Six (6/7: 85.7%) of OXA-type and the TEM-type positives were also CTX-M- positive whereas the other OXA-type positive isolate was SHV-type positive. Most (22/25: 88%) isolates with two types of ESBLs were resistant to both CTX and CAZ. It can be concluded that, in female's genital tract infection, ESBL production, especially CTX-M-type, can be added as another factor, in addition to virulence factors, that select for certain strains to survive and cause disease and as vaginal E. coli is a reservoir along the fecal-vaginal-urinary/neonatal course of transmission in extraintestinal E. coli infections, our clinicalmicrobiology labs and clinicians need to be aware of the presence of these ESBL-producing organisms and should conduct surveillance studies to ascertain this.