Resistance genes to sulphonamide in commensal Escherichia coli isolated from stool of patients in Mansoura University Children Hospital

Commensal bacteria have a great impact on the emergence and spread of antibiotic resistance. This emphasizes a great need to underscore the magnitude of this problem in our locality, and children are taken as a sector in this research because they are usually subjected to heavy load of antibiotic usage. This study aimed at determining sulphonamide resistance genes presence among fecal isolates of commensal Escherichia coli detected in patients attending Mansoura University Children Hospital (MUCH) and to check the value of these commensals in the appearance and transmission of antimicrobial resistance. Forty five (45) co-trimoxazole resistant E. coli were haphazardly chosen for detection of resistant determinant to sulphonamide. The methods used were antibiotic sensitivity tests by disc diffusion, detection of sul and int1 genes by PCR and conjugation assay. Co-trimoxazole resistance was found in 80.3% of the examined fecal commensal E. coli. sul2 gene recorded the highest prevalence in the examined co-trimoxazole resistant E. coli strains (73%). int1 gene was found in 62% of those isolates. 35.5% of the studied isolates had the ability to transmit genes of resistance to the recipient susceptible isolates by conjugation experiment. The recorded great prevalence of resistance genes to sulphonamide in commensal isolates of E. coli among children seems to be alarming which may indicate the future increase in the prevalence of those resistant genes in our community. This problem underlines the necessity of limitation of antibiotic usage, particularly among children.   Key words: Sulphonamide resistance, Escherichia coli, sul genes, integrons.