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Uncomplicated bacterial uroinfections: aetiological structure and antimicrobial susceptibilityof bacterial isolates

Volume 11, Issue 1

Original Article / Published: November 2023


I. Gergova, D. Petrova, O. Gatsev, I. Saltirov

Microbiology Laboratory, Department of Microbiology, Virology, Clinical Laboratory and Immunology, Military Medical Academy, Sofia, Clinic of Nephrology, Department of Urology and Nephrology, Military, Medical Academy, Sofia
Clinic of Urology, Department of Urology and Nephrology, Military Medical Academy, Sofia


Introduction and objective: The increasing resistance to antimicrobials also affects uropathogens, the causative agents of uncomplicated urinary tract infections (UTIs), and is a frequent cause of failure of empirical antimicrobial therapy. The purpose of the study is to analyze the aetiological structure and susceptibility to antimicrobials of the most common bacterial causative agents of UTIs.
Material and Methods: A prospective analysis of microbial findings was performed in patients with clinical evidence of UTIs. A total of 9,426 urine cultures were examined (female: 5,157; male: 4,269).
Results: Microbial growth was found in 29.7% of female urine cultures and in 19.1% of male urine cultures. A total of 2,364 microbial isolates were identified. The aetiological structure of the isolates in both groups was similar – female: E. coli 51.3 %, Enterococcus spp. 18.9%, K. pneumoniae 13.1%, P.mirabilis 4.6%, Candida spp. 1.2%; male: E. Coli 23.5 %, Enterococcus spp.27.4%, K. pneumoniae 19.5%, P. mirabilis 6.4%, Candida spp. 2.8%. A high frequency of resistance was found to cephalosporinsIII generation (ceftriaxone: K.pneumoniae 31.7 %, P. mirabilis 15.2 %), fluoroquinolones (ciprofloxacin: E.faecium 74.0 %, K.pneumoniae 34.4 %, E. faecalis 27.9 %, E. coli 27.0 %, P. Mirabilis 24.0 %) and trimethoprim/sufamethoxazole (K. pneumoniae 33.9 %, P. mirabilis 33.6 %, E. coli 25.3 %,). Resistance to fosfomycin and nitrofurantoin was low. ESBL-producers were more frequent among K. pneumoniae (31.7 %) compared to E. coli (9.3 %). Resistance to carbapenems was found only in K. pneumoniae (14.9 %).
Conclusion: The study showed that the main uropathogens are often resistant to the antimicrobials recommended for empiric antimicrobial therapy in UTIs, necessitating a revision of local recommendations.


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uncomplicated urinary tract infections, aetiological structure, antimicrobial resistance, empiric antimicrobial therapy.

How to cite this article:

I. Gergova, D. Petrova, O. Gatsev, I. Saltirov. Uncomplicated bacterial uroinfections: aetiological structure and antimicrobial
susceptibility of bacterial isolates. Journal of Endourology and Minimally Invasive Surgery (Bulgaria), 2023; 11(1): 56-63

Corresponding author:

Assoc. Prof. Ivanka Gergova, MD, PhD, Military Medical Academy of Sofia, Department of Microbiology, Virolgy, Clinical laboratory and
Immunology Microbiology Laboratory, 3 Georgi Sofiiski blvd Sofia 1606