Abstract

Background:
Urinary Tract Infections (UTIs) are among the most frequent bacterial infections, primarily affecting women but also occurring in individuals of all genders and age groups. These infections arise when harmful microorganisms enter the urinary tract, causing symptoms that range from mild urinary discomfort to severe, potentially fatal conditions, such as sepsis.

Aim:
This study aimed to identify the bacterial pathogens responsible for UTIs and evaluate their antibiotic resistance and sensitivity profiles, which are key factors influencing treatment success. Additionally, the research compared two commonly used laboratory techniques, manual disc diffusion and the automated VITEK®2 system, to assess their reliability in detecting antibiotic resistance patterns in clinical isolates from patients with UTI.

Methods:
A total of 550 urine samples were collected from symptomatic patients at the Central Laboratory in Duhok. Bacterial identification was performed using biochemical tests and was confirmed using the VITEK®2 system. Antibiotic susceptibility testing was conducted using both the disc diffusion method and the VITEK®2 system, with 190 samples analyzed using the latter for comparison.

Results:
Of the samples analyzed, 249 patients were confirmed to have UTIs. The most commonly isolated bacteria were Staphylococcus epidermidis (26.9%), Staphylococcus aureus (20.1%), Escherichia coli (16.5%), Streptococcus pyogenes (5.6%), and Pseudomonas aeruginosa (2.8%). The VITEK®2 system showed complete resistance (100%) to clindamycin, teicoplanin, and tetracycline, whereas linezolid and tigecycline demonstrated full effectiveness (100% sensitivity). In contrast, the disc diffusion method revealed greater variability in antibiotic performance. Imipenem showed excellent effectiveness, while vancomycin and piperacillin exhibited high resistance rates. For vancomycin, the manual disc diffusion method identified significantly more resistant and susceptible cases (135) compared to VITEK®2 (32). Similarly, for levofloxacin, the manual method detected 175 resistant or susceptible strains compared to just 15 with VITEK®2, highlighting its superior detection capability.

Conclusion:
The comparison revealed notable differences in sensitivity patterns, with manual disc diffusion often providing more reliable results for several bacterial species. These findings underscore the importance of using multiple testing methods to accurately assess antibiotic resistance. As antibiotic resistance continues to escalate, ongoing surveillance and the development of novel treatment strategies are crucial to combat the growing threat of multidrug-resistant infections.

Key words: Antimicrobial resistance, Antibiotic susceptibility, VITEK, UTI pathogens, Bacterial prevalence