Prevalence of urinary tract infection and antimicrobial resistance patterns of uropathogens with biofilm forming capacity among outpatients in morogoro, Tanzania: a cross-sectional study

Abstract

Introduction: Urinary tract infection (UTI) is the second most common infectious disease affecting more than 150 million people globally annually. Uropathogenic E. coli (UPEC), the predominant cause of UTI, can occur as a biofilm associated with antimicrobial resistance (AMR). There is a data gap on global AMR patterns from low-income settings, including Tanzania. Data on antimicrobial susceptibility patterns in relation to biofilm formation will help in the proper selection of antibiotics and the fight against AMR.

Methods: This analytical cross-sectional study was conducted among consecutively selected outpatients (n = 344) from January to May 2022 at Morogoro Regional Referal Hospital. Mid-stream urine samples were collected aseptically from symptomatic patients. A significant UTI was defined when more than 10⁵ colonies/ml of urine were recorded. Kirby Bauer's disc diffusion method was used for antibiotics susceptibility patterns and a Congo Red Agar method was used to determine biofilm formation. Two-sided χ2 test or Fisher's exact test, Cohen's kappa coefficient and logistic regression were used for data analysis. A p-value < 0.05 was considered statistically significant.

Results: The prevalence of UTIs was 41% (141/344) and elders (>=60 years) had five times higher odds of having UTI as compared to adolescents (p < 0.001). E. coli was the most predominant bacteria (47%; 66/141), which displayed moderate susceptibility against ciprofloxacin (59.1%) and nitrofurantoin (57.6%). A total of 72 (51%) of all isolated bacteria were multi-drug resistant. All isolated bacteria demonstrated high resistance (> 85%) against ampicillin and co-trimoxazole. In this study, 51.5% (34/66) were biofilm-forming E. coli and demonstrated relatively higher antibiotic resistance as compared to non-biofilm forming bacteria (p < 0.05).

Conclusion: We report high antibiotic resistance against commonly used antibiotics. Slightly more than half of the isolated bacteria were biofilm forming E. coli. A need to strengthen stewardship programs is urgently advocated.

Keywords: Antimicrobial resistance; Biofilm forming bacteria; UTI.

Fig. 1

Study site map. The top right is the map of the Morogoro region. Bottom right is the map of Morogoro Urban. On the left is the map of Tanzania. The study site map was originally generated using ArcGIS software version 10.7.1 (Esri, California, USA; https://www.esri.uconn.edu/software/arcgis-student/)

Fig. 2

Proportion of MDR among the isolated bacteria species. Other species represent non-identified Gram negetive bacilli (p-value is based on the Chi-Square test)

Fig. 3

Antimicrobial resistance patterns among isolated bacteria (`n´ indicate the number of isolates under each bacteria specie)

Fig. 4

Congo Red Agar plates showing non-biofilm forming (A = red colored colonies) and biofilm forming (B = Dry crystalline Black colonies) UPEC isolates