Evolution Profile of Escherichia coli Resistance from January 2009 – April 2013 to Antibiotics at the Yaounde University Teaching Hospital, Cameroon

Many strains of Escherichia coli ( E. coli ) have been proven to be pathogenic and are sometimes responsible for deadly outbreaks. This bacterium has become more resistant to antibiotics to which it is often sensitive. The aim of this study was to study the evolution of E. coli resistance to antibiotics from 2009 to 2013 at the Yaoundé University Teaching Hospital. We included archived bench files containing information on patient’s demographic data and results of antimicrobial susceptibility testing. The data were analyzed using Microsoft office, Excel 2007 software and SPSS. A total of 350 strains of E. coli were collected from both hospitalized and non-hospitalized patients. The antimicrobial susceptibility was tested using 23 antibiotics from January 2009 to April 2013 at the Bacteriology Unit of the Yaounde University Teaching Hospital. We observed a decrease in the trend of the resistance to 8 of the antibiotics tested: Amoxicillin + clavulanic acid, cefuroxime, cefoxitin, imipenem, ofloxacine, colistin, gentamicin and netilmicin. Meanwhile, we noticed an increase in the trend of resistance to 15 antibiotics: Amoxicillin, cephalothin, cefoxitin, cefotaxime, ceftazidime, cefixime, cefepime, aztreonam, amikacin, nalidixic acid, norfloxacin, ciprofloxacin, trimethoprim-sulfamethoxazole, nitrofurantoin, chloramphenicol, fosfomycin). The trend observed were statistically significant, for the resistance rate to amoxicillin + clavulanic acid (P value=0.002), also to resistance rates of amikacin and cefotaxime (P-values=0.008 and 0.014 respectively). This increase in resistance over the years to most of the commonly used antibiotics has caused E. coli to be classified among multidrug resistant bacteria. In order to avoid a therapeutic impasse, it is necessary to carry out sensitization against the abusive use of antibiotics; surveillance activities for multidrug resistant bacteria and nosocomial infections should be reinforced as E. coli is one of a most common nosocomial bacteria.