Detection of Escherichia coli O157:H7 and O104:H4 in patients with diarrhea in Northern Lebanon and characterization of fecal E.coli producing ESBL and carbapenemase genes

Background. While most strains of Escherichia coli (E. coli) are harmless, some are causing intestinal infections of varying severity. Then Shiga toxin-producing E. coli (STEC)/ enterohemorrhagic E. coli strains can be associated with fatal clinical manifestations. Of these E. coli Serotypes O157: H7 and O104: H4 were responsible for worldwide epidemics causing thousands of intestinal infections and dozens of deaths.The aim of this research is to investigate the prevalence of E. coli O157: H7 and O104: H4 in the diarrheal stools of 242 Lebanese patients.Materials and methods. This study includes 242 E. coli strains isolatedfrom fecal specimens of patients with diarrhea between February2013 and May 2014 in the microbiology department of Nini HospitalLaboratory in Tripoli - North Lebanon. All specimens were inoculatedon sorbitol MacConkey agar. Sorbitol negative strains were investigated for detection of stx1, stx2 and eae genes using real-time PCR. All carbapenem-resistant strains and ESBL producers were investigated by PCR for presence of KPC, IMI, NMC-A, EMS, GHG, VIM, NDM, IMP,OXA-48, blaTEM, blaCTX-M, blaSHV, blaOXA, blaGES and blaPER..Results. A total of 14 sorbitol negative strains were detected. The search for stx1, stx2 and eae genes showed the presence of a single positive strain for E. coli O157: H7. Out of 242 E.coli strains, 48 (19.8%) were ESBL-positive, 4 (1.6%) were resistant to ertapenem, and all were negative for stx2 genes, The blaCTX-M gene was the most frequentamong ESBL positive strains (85%), followed by the blaTEM gene (50%). One strain had the blaNDM-1 gene, another had the blaOXA-48 gene and 2 strains were probably resistant due to impermeability.Conclusion. The results of this study demonstrate rarely presence of enterohemorrhagic E. coli, but shows the frequent presence of multidrug resistant E.coli in the intestinal flra of North Lebanese patients. Therefore, it is important to search for MDR E.coli in the intestinal flra of patients who are going to be treated with major operations or those admitted to intensive care units