s Risk Factors Associated with Resistance in CTX-M Producing E. coli Isolates

CTX-M is the most frequent type of extended spectrum beta-lactamase. It is an important cause of anti-microbial resistance against cephalosporins and a recent concern in treating infections caused by Gram negative bacteria. Although Escherichia coli has become the major carrier of the genes, these enzymes were reported in many other bacterial species. The aim of this study was to determine risk factors associated with resistance in CTX-M producing E. coli isolated from patients admitted in Sanandaj city hospitals. The study was a case control investigation. A case patient was defined as a patient from whom a resistant strain of E. coli producing CTX-M was recovered. The control patient was the one who carried a cephalosporin sensitive E. coli strain. The presence of CTX-M was investigated both by a phenotypic method (double disk diffusion); as well as, genotypically by PCR. The potential risk factors for resistance trait were monitored with patient's history and current situations. The main risk factors for CTX-M associated infection were found to be associated with ICU hospitalization (OR 5.702 CI95% 2.286-14.223), mechanical ventilation (OR 5.043 CI 95% 2.082-12.213) and the presence of urinary catheter (OR 11.629 CI95% 3.694-36.613). In conclusion; ICU stay, mechanical ventilation and urinary tract catheter were found to be the most predisposing factors in spread of CTX-M family in hospital environments. It seems that more sophisticated programs are needed to control of this conditions.