High Incidence of Antibiotic Resistance in the Uropathogenic Bacteria Associated with Different Urological Diseases and Metabolic Complications: A Single Center Cross-Sectional Study

Urological diseases affect all age groups and are associated with different urinary complications. Presence of pathogenic bacteria complicates the urological diseases such as chronic kidney disease (CKD), kidney stone disease (KSD), emphysematous pyelonephritis (EPN), and urological cancers (UCs) coinciding with urinary metabolic complications. The One Health concept for preventing the spread of antibiotic resistant opportunistic pathogens necessitates detailed investigation on the virulence and the antibiotic sensitivity patterns of the pathogens from the urinary tract infections (UTIs). This cross-sectional study was aimed to profile the pathogenic bacteria associated with different urological diseases that included urine samples from the patients from a tertiary care hospital. The study included 258 patients representing CKD (15.1%), KSD (28.7%), EPN (15.5%), UC (12.0%), and UTI patients without any urological diseases (28.7%) with overall 70.5% patients showing positive urine culture. Furthermore, other than UTI in patients without any urological diseases (100%), higher culture positive cases were seen in KSD (64.9%), followed by CKD (61.5%), EPN (52.5%), and UC (48.4%). Escherichia coli was the most predominant bacteria in UTI (35.1%) and EPN (66.7%). In KSD, Pseudomonas aeruginosa (41.7%), Staphylococcus aureus (18.8%), and Proteus mirabilis (14.6%) were more common. S. aureus (86.7%) was the most isolated bacteria from the UC cases. Overall rate of multidrug resistance (MDR) was 77.8%. All (100%) E. coli, K. pneumoniae, P. mirabilis, and S. aureus strains were MDR. Among the strains, strong biofilm formation was observed in 73.6%, and 66.7% strains were urease positive. Biofilm was positively correlated with MDR and urease activity. The abundance and distribution of bacteria differed among the urological diseases suggesting their association with the urine metabolite profile. Colonization of MDR pathogens in patients with urological diseases is a serious concern requiring steps to control the emergence of drug resistance and their further spread into the ecosystem.

Differential expression of urease genes and ureolytic activity of uropathogenic Escherichia coli and Pseudomonas aeruginosa isolates in different nutritional conditions

Uropathogens have adaptation strategies to survive in the host urinary tract by efficiently utilizing and tolerating the urinary metabolites. Many uropathogens harbour the enzyme urease for the breakdown of urea and the enzymatic breakdown of urea increases the pH and facilitate the struvite crystallization. In this study, the differential urease activity of uropathogenic Escherichia coli and Pseudomonas aeruginosa strains was investigated under different nutritional conditions. The experiments included measurement of growth, pH, urease activity, NH4-N generation and urease gene (ureC) expression among the bacterial strains under different conditions. Further, the implications of urea breakdown on the struvite crystallization in vitro and biofilm formation were also assessed. The study included urease positive isolates and for comparison urease negative isolates were included. Compared to the urease negative strains the urease positive strains formed higher biofilms and motility. The urease positive P. aeruginosa showed significantly higher (p < 0.01) pH and urease activity (A557-A630) compared to E. coli under experimental conditions. Further, supplementation of glucose to the growth media significantly increased the urease activity in P. aeruginosa and in contrast, it was significantly lower in E. coli. The expression profile of urease gene (ureC) was significantly higher (p < 0.001) in P. aeruginosa compared to E. coli and was consistent with the biochemical results of the urease activity under the nutritional conditions. The differential urease activity under two nutritional conditions influenced the biogenic struvite crystallization. It correlated with the urease activity showing higher crystallization rate in P. aeruginosa compared to E. coli. The results highlight the differential urease activity in two common uropathogens under different nutritional conditions that may have significant role on the regulation of virulence, pathogenicity and in the kidney stone disease.