Prevalence of gram-negative bacterial causes of urinary tract infection and their antimicrobial susceptibility profile at the university teaching hospitals in Lusaka, Zambia

Background

Urinary Tract Infections (UTIs) are the most common bacterial infections in healthcare facilities in developing countries. They are often treated empirically based on local etiological agents and bacterial antimicrobial susceptibility data.

Objective

To determine the prevalence, etiological agents, and antimicrobial susceptibility patterns of Urinary Tract Infections at the University Teaching Hospitals in Lusaka, Zambia.

Methods

A cross-sectional study was conducted on in-patients of all age groups and gender. A total of 621 urine samples were processed in the bacteriology laboratory. Bacterial identification of aetiological agents of UTIs was done on the Vitek 2 Compact, while antimicrobial susceptibility was done using the Kirby-Bauer disk diffusion method. Statistical Package for the Social Science (SPSS) version 20 was used for data analysis.

Results

There was a total number of 108 (17.6 %) significant bacteriuria growth. Gram-negative bacteria isolates constituted 75 %, and Gram-positive were 25 %. Escherichia coli was the dominant isolate at 41.7 %, followed by Klebsiella pneumoniae at 19.4 %. Gram-negative showed high resistance ampicillin 96.2 %, trimethoprim/sulfamethoxazole 87.3 %, and ciprofloxacin 64.2 %. Nitrofurantoin (25.3 %) and piperacillin/tazobactam (4.9 %) had a low resistant rate, while all isolates had 100 % susceptibility to imipenem.

Conclusion

Gram-negative bacteria, especially E. coli and Klebsiella pneumoniae were the common causes of UTI at the study site. These isolates showed a high rate of resistance to the recommended antibiotics used in the treatment of UTIs. Routine monitoring of antimicrobial susceptibility patterns of uropathogens should be encouraged to guide treatment of UTIs. Local antibiograms should be developed and/or updated to guide UTIs’ treatment.