Abstract

COEXISTENCE OF CTX-M, GES AND IMP GENES IN GRAMNEGATIVE BACILLI AND THEIR MULTI RESISTANCE TO BETALACTAMS AT SAINT CAMILLE HOSPITAL IN OUAGADOUGOU (HOSCO)

Pêgdwendé Rose Bonkoungou*, Amana Mètuor Dabiré, Oumar Traoré, Rahimatou Yasmine Wendkuni Tiemtoré, Théodora Mahoukèdè Zohoncon and Jacques Simporé

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Abstract

Extended-spectrum ß-lactamases (ESBLs) are bacterial plasmid or chromosomal enzymes capable of inactivating Penicillins, Cephalosporins, Aztreonam and inactive on Carbapenems. They are encoded by the beta-lactamase genes (bla genes) of the IMP family (Imipenemase), GES (Guyana Extended Spectrum), CTX-M (Cefotaximase – Munich). Bacterial resistance by ESBL production has become a global public health problem because it seriously compromises antimicrobial therapies. The objective of this study was to characterize the CTX-M and GES type ESBL genes as well as the IMP type carbapenemase gene carried by Gram-negative bacilli at Saint Camille Hospital in Ouagadougou (HOSCO). Ninety-five (95) strains of Enterobacteriaceae were collected at HOSCO and tested for antibiotics (AMC, ATM, IMP, CTX, CRO and CAZ). Resistant strains, the detection of resistance genes coding for extended spectrum beta-lactamases (ESBLs) were carried out at LABIOGENE by conventional PCR. The strains were mainly isolated in the urine (54.74%), and showed strong resistance to AMC penicillins 90.52%, to Aztreonam 75.78% to C3Gs: 70.52% CTX, 68.42% CAZ and 64.21% CRO; and imipenem (54.73%). Escherichia coli was the most frequent species (51) followed by Klebsiella spp (24). The ESBL phenotype was found in 31.57% of the strains, which were positive by conventional PCR. The IMP gene (17.89%) dominated the resistance gene profile followed by CTX-M (8.42%) and GES (5.26%). ESBL CTX-M was more produced by Escherichia coli (6.31%) and GES by Pseudomonas spp (3.15%). Escherichia coli was the majority species that harbored these genes. Analysis of PCR products after agarose gel electrophoresis confirms the presence of resistance genes coding for the GES, CTX-M and IMP genes. These genes were mainly detected in E. coli and then in Pseudomonas spp. This study reveals the coexistence of resistance genes of bacterial strains encountered in the clinical environment, hence the need for the establishment and support of an antibiotic resistance monitoring unit.

Keywords: BGN, ESBL, blaIMP, blaGES, blaCTX-M, HOSCO.