Epidemiology and Sensitivity to Antibiotics of Enterobacteriaceae Producing Extended-Spectrum Beta-Lactamases (ESBL) in the Region of Nouakchott (Mauritania)

Introduction: Extended-spectrum beta-lactamases (ESBL) are a large heterogeneous family of bacterial enzymes discovered in 1980. They are induced either by plasmids or by mutation of the natural genome in the bacterium. Both mechanisms give affected bacteria the ability to hydrolyze a very wide variety of beta-lactams. (ESBL)-producing bacteria represent a major concern due to their epidemic spread and their multiresistance to antibiotics The purpose of this study was to: determine their frequency of ESBL, know their distribution according to sex, hospital department, assess their levels of resistance to antibiotics and educate clinicians on the rational prescription of antibiotics. Materials and Methods: This is a retrospective study which was carried out within the central laboratory of the National Hospital Center of Nouakchott (CHN) over two years. The antibiogram was carried out by the method of diffusion in agar medium or on the Vitek-2 automaton (Biomérieux®) The production of ESBLs has been demonstrated by looking for a synergy between clavulanic acid and third-generation cephalosporins according to the usual techniques. Results: Out of 650 species of Enterobacteriaceae, 18.46% produced ESBL, including 58% in hospitalized patients and 42% in outpatients. The ESBL resistance rate was high to quinolones, aminoglycosides (except amikacin) and cotrimoxazole, fosfomycin and carbapenems retain good activity. Discussion: ESBLs are increasingly incriminated in both community-acquired and nosocomial infections and represent a real public health problem. In fact, 42% of ESBL isolated during our study came from outpatient consultations. This dissemination of ESBL in the community is alarming and could be explained, in part, by the anarchic use of antibiotics, it has also been mentioned by several studies. Fosfomycin retains excellent efficacy against ESBL in our study with 90% sensitivity. The resistance of Enterobacteriaceae to carbapenems remained marginal with sensitivity rates of 98 to 100% , making them the best treatment against ESBL-producing Enterobacteriaceae. However, the misuse of these molecules has led to the emergence of resistance to these antibiotics, especially in certain enterobacteriaceae. Conclusion: Considering the results of our study and the data from the literature, it clearly appears that ESBLs are taking an increasingly important place among multiresistant bacteria. The increase in resistance should be compared with the increase in antibiotic consumption. These trends are problematic because they promote not only the emergence and spread of ESBL enterobacteriaceae, but also those of carbapenemase-producing enterobacteriaceae (CPE). Faced with this worrying situation and given the increased risk of therapeutic impasse caused by these multi-resistant strains; very early detection of ESBL germ infections, isolation of patients carrying a transmissible infection and rational use of antibiotics should be carried out.