Detection of Antibiotic-Resistance Genes associated with S. aureus and E. coli from Patients with Diabetic Foot Infection from Selected Hospitals in Katsina Metropolis, Katsina State, Nigeria

Abstract

Diabetic foot infections (DFI) is one of the most serious clinical complication among diabetic patients, often resulting in morbidity and healthcare burdens. The emergence of antibiotic-resistant bacteria among diabetic foot ulcers patients poses a major challenge in the treatment of these infections. This study investigated the antibiotic resistant profiles of Staphylococcus aureus and Escherichia coli isolates from patients with diabetic foot infections at selected hospitals in Katsina metropolis, Katsina State, Nigeria. A total of 150 wound samples were collected from patients diagnosed with DFI in two hospitals (i.e Federal Teaching Hospital Katsina and General Hospital Katsina). Isolates were preliminarily identified and characterized using standard microbiological techniques, while antibiogram were determined using disk diffusion method. Multi-Drug Resistant (MDR) isolates were selected for PCR amplification of antibiotics resistance genes based on their resistance to ≥ 3 classes of antibiotics. S. aureus and E. coli identities were confirmed by PCR amplification of the uidA and nuc genes, respectively. Antibiotic resistance genes amplified among selected S. aureus include: mecA, qnrA and parC for methicillin and quinolone resistance, respectively while amplification of bla_TEM and bla_CTX for beta-lactam resistance were carried out for selected E. coli isolates. Forty four (44) isolates were isolated from this study, a total of 22 representing each of S. aureus and  E. coli, respectively. Among the E. coli, high (100%) resistance to each of cefuroxime, ciprofloxacin, ofloxacin, augmentin, ampicillin and erythromycin was observed. S. aureus showed 100%, 95%, 45% and 27% resistance to pefloxacin, ciprofloxacin, cefoxitin and gentamicin, respectively. All isolated E. coli (22, 14.66%) and S. aureus (6, 8%) from this study, were MDR. Among the selected MDR, 83.3% (5/6) and 100% (4/4) identities were confirmed as S. aureus and E.coli, respectively by PCR amplification while 16.7% (1/5) of the selected MDR S. aureus tested positive for each of parC and mecA gene, whereas, 100% (4/4) and 50% (2/4) of selected MDR E. coli tested positive for bla_TEM and bla_CTX, respectively. The study concluded that wounds of diabetic patients harbored MDR strains of both S. aureus and E. coli, carrying various antibiotics resistance genes, thus, likely hindering accelerated healing process in the course of treating diabetic foot ulcers. Therefore, there is urgent need for surveillance and appropriate antimicrobial stewardship.

Keywords: Antibiotics, Diabetic foot infection, Multi-drug resistance, Genes