Phenotypic and genotypic characterization of the most prevalent microbial pathogens in diabetic patients’ clinical samples

Abstract

Background: Diabetes mellitus (DM) is one of the known risk factors for many infections due to the uncontrolled hyperglycaemia that causes immunocompromised state of patients. This study was thus carried out to compare the most prevalent pathogenic organisms and their antimicrobial susceptibility patterns in both diabetic and non-diabetic patients. Methods: We collected 169 non-duplicate clinical isolates from different clinical samples. Identification of the isolates up to spp. level and antimicrobial susceptibility profiles were performed by VITEK® 2 compact system. The extensively drug-resistant (XDR) and pan drug-resistant (PDR) isolates were selected for the detection of beta-lactamase genes using PCR. Results: 55.6 % of all isolates were collected from diabetics, while 44.4 % were collected from non-diabetics. Gram-negative bacteria were the most prevalent (80.5%), followed by Candida species (10.7%), then Gram-positive bacteria (8.9%). Most of the Gram-negative bacteria in diabetic patients showed a high resistance rate to ciprofloxacin (80.8%) and cefazolin (78.2%). However, in non-diabetic patients, high resistance rate was found to ampicillin (70.7%), ceftriaxone (67.2%) and cefepime (65.5%). Most of the Gram positive bacteria in diabetic patients showed high resistance rate to benzyl penicillin (71.4%). 72.2% of the isolates showed resistance to ≥ three antibiotics; 60.7% were from diabetics and 39.3% were from non-diabetics. The frequency of beta-lactamase genes among isolates from diabetics was found to be 68.6% but only 46.4% among isolates from non-diabetics. High frequencies of blaOXA-48-like (84.9%) were found. Conclusions: Antibiotic abuse and immunocompromised state of uncontrolled diabetics were highly associated with multidrug resistance.