Molecular Detection of blaCTX-M-G1, blaVIM blaIMP and mcr Genes in Extended Spectrum β-Lactamase Bacilli Isolated at Schiphra Protestant Hospital, Ouagadougou, Burkina Faso

Abstract

Background and Aim: Infectious diseases nowadays are caused by multidrug-resistant bacteria, making their management both difficult and costly. In Gram-negative bacilli, several enzymes particularly ESBLs and carbapenemases allow to counteract the antibiotic effect of nearly all β-lactams. This leads to a dilemma for clinicians who increasingly include last-resort drugs in therapeutic options. The objective of this study is to focus attention on the precarious situation of antibiotic drugs, even those considered last-resort like colistin. It aims precisely to characterize the blaCTX-M-G1, blaIPM, blaVIM genes and the mcr gene in Gram-negative bacilli producing ESBL. Methodology: A total of 60 strains of Gram-negative bacilli isolated from clinical samplesbetween December 2022 and March 2023 at Shiphra Hospital in Ouagadougou were first subjected to sensitivity test against β-lactamantibiotics using disc diffusion method. Then a synergy test was performed for the phenotypic detection of ESBL producers. Finally, a conventional PCR was performed for isolation of the targeted resistance genes. Results: Of the 60 strains studied, the sensitivity test showed that 86.67% and 88.33% were respectively resistant to ceftazidime and cefotaxime. However, most of isolates were found sensitive to carbapenem drugs. There were 76.67% and 83.33% for meropenem and imipenem respectively. The synergy test revealed that 76.67% of our strains produced ESBLs. Electrophoresis of PCR products revealed 89.13% of strains carrying at least one of the resistance genes studied. All these strains harbored the CTX-M-G1 gene while 6.52% carried also the VIM gene. The IMP genes and the mcr genes were not detected. Conclusion: This study showed that several Gram-negative bacilli harbor resistance genes  against last-resort antibiotics at the Schiphra Protestant Hospital. The results obtained raise the need to regulate the use of antibiotics in order to prevent the emergence of multidrug-resistant bacteria.