Prevalence of Extended Spectrum Beta-Lactamase Phenotype and blaCTX-M-I, blaSHV, and blaTEM Genes among Uro-Pathogenic Escherichia coli Isolates, in Egypt

One of the main reasons for recurrent urinary tract infections (UTIs) could be explained as follows: it is well approved that uro-pathogenic E. coli (UPEC) isolates have the ability to persist in urothelial cells, therefore, it can cause recurrent UTIs. The prevalence of extended-spectrum beta-lactamase (ESBL) has been considered a global health issue. It is well documented that the blaCTX-M, blaSHV, and blaTEM are the prevailing beta-lactamase. Therefore, the current study was designed to determine the ESBL production and prevalence of blaCTX-M1, blaSHV and blaTEM genes among UPEC isolated from 3 hospitals during 2020-2021, Egypt. Total of 111 isolates were obtained from three different hospitals in Egypt during the years 2020-2021. The antibiotic susceptibility testing was conducted according to CLSI advice. The combine disk was used for phenotypic ESBL production. The MIC of ceftazidime was conducted with the micro-broth dilution test. The cloxacilin containing MH agar was used to detect the AmpC-lactamase. The PCR assay was used to detect the blaCTX-M-I, blaSHV and blaTEM genes. The results revealed that in the broth microdilution method, 103 (92.7%) isolates showed MIC≥1, and in the combined disk method, 89 (80.1% of all) were ESBL producers. On the other hand, among 91 ceftazidime resistant isolates, 86 (77.4% of all) were ESBL positive. The difference between the 2 methods for ESBL confirmation was not significant. The results of MIC confirmed the disk diffusion for determination of phenotypic test for ESBL production. The prevalence of blaCTX-M-I, blaSHV and blaTEM genes among ESBL producers was 77.4% (n=86), 47.4% (n=53) and 2.4% (n=2) respectively. These enzymes were amplified in a wide range of MIC to ceftazidime. The prevalence of MDR UPEC and ESBL positive isolates was high in military hospitals in Egypt. The majority of UPEC isolates amplified blaCTXM-I and blaSHV type β–lactamases. One-third of isolates were positive for both these genes. There was no relation between MIC range of ceftazidime and presence of beta-lactamase genes.