The Microbial Etiology of Urinary Tract Infections in a Tunisian Orthopedic Institute | Chapter 2 | Medical Science: Recent Advances and Applications Vol. 3

Background: Urinary Tract Infections (UTIs), frequently encountered both in hospitals and community settings, are among the most common reasons for medical consultations in daily practice and constitute a significant driver of antibiotic consumption. The microorganisms most frequently isolated during these infections are Gram-negative bacilli, with Escherichia coli at the top of the list.

Aim: This study aimed to characterise the microbiological profile of Tunisian patients with UTIs and evaluate antibiotic resistance patterns over three years at the Orthopaedic Institute.

Methods: Urine samples collected between January 1, 2019, and December 31, 2021, were analysed. Standard laboratory procedures were employed to identify bacterial strains, and the Microscan Walkway 40 Plus system was used for biochemical assays and antibiotic susceptibility testing. E. coli ATCC 25922, Enterococcus feacalis ATCC 29212, Pseudomonas aeruginosa ATCC27853, Staphylococcus aureus ATCC29213 were used as a control strains. Results were interpreted according to EUCAST guidelines.

Results: A total of 1,313 bacterial strains were isolated. The analysis revealed a predominance of Enterobacteriaceae (96.8%), with Escherichia coli (52.2%) and Klebsiella pneumoniae (19.3%) being the most common pathogens. Antibiotic resistance rates in hospital-acquired E. coli strains were as follows (in descending order): amoxicillin (73.05%), trimethoprim/sulfamethoxazole (46.9%), ofloxacin (40.3%), amoxicillin/clavulanic acid (35.05%), and gentamicin (20.5%). Resistance to fosfomycin was low for E. coli (2.6%) in hospitals but higher for K. pneumoniae (≥12.1%). Amikacin resistance remained moderate, affecting ≥20% of E. coli strains and 10% of K. pneumoniae. Nitrofurantoin resistance was minimal in E. coli (1.06%) but significant in K. pneumoniae (21.5%). The production of Extended-Spectrum Beta-Lactamases (ESBLs) was observed in 19.3% of K. pneumoniae and 14.4% of E. coli isolates.

Conclusion: The prevalence of ESBL-producing E. coli and K. pneumoniae in UTIs is on the rise. Continuous surveillance of resistance patterns is essential to guide empirical treatment and mitigate the spread of multidrug-resistant strains. In future, clinico-bacteriological studies with a high level of scientific evidence must be carried out to increase the strength of the recommendations.

 

Author (s) Details

Hajer Kilani
Microbiology Unit, Clinical Biology Laboratory, Mohamed Kassab Institute of Orthopedics, Tunis, Tunisia and Faculty of Medicine, LR99ES09 Laboratory of Antibiotic Resistance, University of Tunis El Manar, Tunis, Tunisia.

 

Salma Kaoual
Microbiology Unit, Clinical Biology Laboratory, Mohamed Kassab Institute of Orthopedics, Tunis, Tunisia and Department of Biology B, Faculty of Pharmacy, University of Monastir, Monastir, Tunisia.

Fatma Kaabi
Microbiology Unit, Clinical Biology Laboratory, Mohamed Kassab Institute of Orthopedics, Tunis, Tunisia.

 

Ilhem Boutiba-BenBoubaker
Faculty of Medicine, LR99ES09 Laboratory of Antibiotic Resistance, University of Tunis El Manar, Tunis, Tunisia and Department of Microbiology, Hospital of Charles Nicolle, Tunis, Tunisia.

 

Sophia Bouhalila Besbes
Microbiology Unit, Clinical Biology Laboratory, Mohamed Kassab Institute of Orthopedics, Tunis, Tunisia and Department of Biology B, Faculty of Pharmacy, University of Monastir, Monastir, Tunisia.

 

 

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