Comparison Between Urinary Tract Infection Bacteriuria in Diabetic and Non-Diabetic Patients Identified by VITEK 2 and 16S rRNA Sequencing Against Some Biological Factors

Abstract

Objective: To investigate the prevalence and characterization of bacterial species associated with urinary tract infections in both diabetic and non-diabetic patients. 

Study Design: Comparative study 
Place and Duration of Study: This study was conducted at the College of Science, University of Basrah, Iraq from 1st November 2022 to 31st January 2023. 

Methods: One hundred and one midstream urine samples from UTI outpatients (61 diabetic, 39 non-diabetic) were collected. Samples cultured on MacConkey, Blood and Nutrient Agar (Accumix, India) at 37°C for 24h. Macroscopic urinalysis with 10 chemical tests (glucose, protein, pH, bilirubin, blood, ketone, leukocyte, nitrite, specific gravity and urobilinogen) done on all samples. Pure colonies obtained by subculturing, maintained on Nutrient Agar slants and Broth. Gram stain used for preliminary isolate classification. 

Results: Forty-eight (60.7%) were from diabetic patients compared to 31 (39.2%) from non-diabetics (P≤0.05). Gram-positive bacteria were the most prevalent in diabetics (58.3%) versus Gram-negative (54.8%) in non diabetics.16S rRNA sequences in both groups showed Escherichia coli being the most common followed by K. pneumoniae, E. fergusonii , S. hominis, E. Hormaechei, R. Ornithinolytica and S. aureus. While in diabetes were only B. safensis, S. saprophyticus, K. rhizophila, M. vitulinus, S. epidermidis, L. bacterium, C. amalonaticus, M.luteus, P. Gergoviae and P. fragi. Whereas in non-diabetes C. aurimucosum, B. velezensis, E. cloacae, C. Erwinia and E. bugandensis. Importantly, Enterobacter bugandensis was isolated from the urinary tract infection as the first time. VITEK showed only 26.1% of species identifications. Multiple alignment of 16S rRNA showed allelic differences between diabetic and non-diabetic bacteria. Sugar lysis tests showed Gram positive isolates from diabetics had 93 reactions vs. 43 in non-diabetics (P≤0.05), with no difference in Gram negative species. 

Conclusion: The diabetic case influences on the types of bacterial species presents, genetic nucleotide mutations and bacterial enzymes activity either for gram positive or gram negative bacteria.