Abstract:
Introduction: Chronic kidney disease (CKD) is a global disease. Diabetes and hypertension are
major risk factors for CKD, while bacterial colonization in the urinary system causes rapid disease
progression. Objectives: To identify the urinary bacterial diversity in diabetic and hypertensive
nephropathy patients rather than identifying urinary infections and study the alteration in bacterial
diversity with CKD progression. Methods: Mid-stream clean catch urine samples were collected
from the study subjects (n=105), including diabetic nephropathy (DN), hypertensive nephropathy
(HT), CKD with both diabetes and hypertension (HD), other aetiology of CKD (O), and healthy
controls (HC). Urine samples were cultured using cystine lactose electrolyte-deficient agar
medium, and a panel of biochemical tests was used to identify the bacterial
species. Results: Bacterial growth was observed in only 31.43% of urine samples. Escherichia
coli, Klebsiella spp., and Staphylococcus aureus were predominantly identified in DN patients
with the highest mean bacterial load (DN: >105 CFU mL-1, HT, HD, and O: between 104 and105
CFU mL-1 and HC: <104 CFU mL-1). Pseudomonas spp. was the most predominant bacteria
isolated from HT, HD, and O CKD study groups. Further, Escherichia coli and Klebsiella spp. had
been predominantly isolated from early-stage (stages 1-3) CKD patients. In
contrast, Pseudomonas spp. and Enterobacter spp. had been isolated from late-stage (stages 4-5)
CKD patients. Conclusions: The findings suggest that diabetes predisposes to urinary bacterial
colonization in CKD, while greater bacterial diversity is associated with increased disease
progression. Further validation is required with a large cohort before clinical application.
