Determination of Quinolone Resistance Genes among Clinical Isolates of Pathogenic Enterobacteriaceae: A Case Study

Abstract

With growing morbidity and mortality, particularly in developing nations like Nigeria, increasing multidrug resistance among Enterobacteriaceae has complicated treatment choices. The commonly recommended remedy for infections caused by these agents is Fluoroquinolones (FQs). This study investigates the characteristics of FQs resistance genes within the clinical isolates of Enterobacteriaceae. It also determined the antibiotic resistance pattern of the isolates in the Yola metropolis of Adamawa State, Nigeria. A total of 472 Enterobacteriaceae isolates recovered from the targeted patients tested for antimicrobial susceptibility. Disc diffusion technique was employed to determine antibiotic susceptibility and resistance. Deoxyribonucleic acid (DNA), gyrB, and ParC were confirmed using multiplex PCR. DNA sequencing technique was carried out to identify alterations in the gyrB and ParC. About (27%) of isolates were resistant to quinolones (Perfloxacin), 32 % to Aminoglycosides (Streptomycin) and 20% to sulfonamides (Septrin). Multiple antibiotic-resistant phenotypes with multiple antibiotic-resistant indexes (MAR) ranging between 0.4 to 0.8 indicates similarity to 13 different species of Enterobacteriaceae. Three were shown to be Salmonella species, 5 Citrobacter, 2 Enterobacter, 1 Aeromonas taiwanensis, 1 Kluyvera genomosp and 1 Escherichia coli harbouring one or more gyrB, each indicating various alterations in the genes. While just one gene can explain quinolone resistance, both the gyrB and parC genes are involved in the resistance to fluoroquinolones. High resistance to FQs is conferred by QRDR gene accumulation and mutations. These findings highlight the pressing need for legislation prohibiting the over-the-counter sale of antibiotics, as is the case currently.