Molecular Detection of blaTEM and blaSHF in Diarrhoegenic Escherichia coli Isolated from Egyptian Children

Introduction: Escherichia coli (E.coli) is a common bacterial pathogen for acute diarrhea in children. The aim of the present study was to determine the prevalence mainly of TEM and SHV-beta lactamase-encoding genes responsible for extended spectrum beta lactamase (ESBL) production amongst diarrheagenic E. coli species as these strains are reported to have been increased in recent years. Methodology: The study included children with acute diarrhea presented in Mansoura University children hospital during the period from January 2011 till Jun 2014. In the microbiological laboratory stool samples were cultured and the isolated colonies were identified by standard biochemical reactions and by multiplex polymerase chain reaction (PCR) for identification of diarrheagenic E.coli strains. In vitro susceptibility testing of all isolates was performed using the discs diffusion method. E.coli isolates were subjected to testing to detect the possible presence of SHV, and TEM genes by conventional PCR. Results and Conclusion: The study included 600 children presented as acute diarrhea. Acute diarrhea caused by E.coli was detected in 160 samples. ESBL genes either TEM or SHF was detected in 31.1% of isolated E.coli. The commonest gene was TEM (22.5%), then SHF (10%). Combined genes were detected only in 2 isolates, table 6. The commonest resistance pattern of E.coli harboring ESBL genes cefepime (100%), cefazolin (96%) and cefotaxime (96%) and for non beta lactams the commonest was for ciprofloxacin (88%), amikacin and tobramycin (20% for each), Table7. From this study we can conclude that extended beta lactamase production is common among diarrheagenic Escherichia coli isolated from children below 5 years. The bla-TEM is the common genetic mechanism for extended beta lactamase production in these isolates followed by bla-SHF.