Antibiotic Resistance Among Gram-Negative Bacteria Isolated from Urinary Tract Infections

• Alaa Mohammed Shihab

  Department of Microbiology, Department of Microbiology, Umm Marzam General Hospital, Libya

  Author

• Salma O Jadallah

  Department of Botany, Faculty of Science, Omar Al-Mukhtar University, Al-Bayda, Libya

  Author

• Ismail saad

  Faculty of Life Sciences, Libyan Academy, AL-Jabal Al-Akhdar Branch, Libya.

  Author

Background: Urinary tract infections (UTIs) are among the most common infections worldwide, usually caused by Gram-negative bacteria such as Escherichia coli and Klebsiella pneumoniae. The rise of multidrug resistance has made treating these infections more challenging. Objective: This study aimed to identify the prevalence and antibiotic resistance patterns of Gram-negative bacteria causing UTIs at Umm Marzam General Hospital. Methods: Between December 2024 and February 2025, we collected 50 urine samples from patients suspected of having UTIs. We identified bacterial isolates using standard microbiological and biochemical tests and performed antibiotic susceptibility testing with the Kirby-Bauer disk diffusion method following CLSI guidelines. Results: The most common isolates were E. coli (76%), Klebsiella spp. (17%), and Proteus spp. (9%). We found high levels of resistance to ampicillin (>60%), trimethoprim-sulfamethoxazole (>50%), and ciprofloxacin (>40%). Nitrofurantoin and fosfomycin showed the best results, with susceptibility rates above 70%. Many isolates demonstrated multidrug resistance. Conclusion: This study shows high rates of antibiotic resistance among Gram-negative uropathogens at Umm Marzam Hospital, limiting treatment options. The results highlight the urgent need for routine susceptibility testing and antimicrobial stewardship programs to support effective treatment and prevent the spread of resistant strains.

Bebell, L. M., & Muiru, A. N. (2014). Antibiotic use and emerging resistance: How can resource-limited countries turn the tide? Global Heart, 9(3), 347–358. https://doi.org/10.1016/j.gheart.2014.08.009 DOI: https://doi.org/10.1016/j.gheart.2014.08.009

Donlan, R. M., & Costerton, J. W. (2002). Biofilms: Survival mechanisms of clinically relevant microorganisms. Clinical Microbiology Reviews, 15(2), 167–193. https://doi.org/10.1128/CMR.15.2.167-193.2002 DOI: https://doi.org/10.1128/CMR.15.2.167-193.2002

Flores-Mireles, A. L., Walker, J. N., Caparon, M., & Hultgren, S. J. (2015). Urinary tract infections: Epidemiology, mechanisms of infection and treatment options. Nature Reviews Microbiology, 13(5), 269–284. https://doi.org/10.1038/nrmicro3432 DOI: https://doi.org/10.1038/nrmicro3432

Foxman, B. (2014). Urinary tract infection syndromes: Occurrence, recurrence, bacteriology, risk factors, and disease burden. Infectious Disease Clinics of North America, 28(1), 1–13. https://doi.org/10.1016/j.idc.2013.09.003 DOI: https://doi.org/10.1016/j.idc.2013.09.003

Gupta, K., Hooton, T. M., Naber, K. G., Wullt, B., Colgan, R., Miller, L. G., Moran, G. J., Nicolle, L. E., Raz, R., Schaeffer, A. J., & Soper, D. E. (2017). International clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women: A 2017 update. Clinical Infectious Diseases, 64(6), e25–e32. https://doi.org/10.1093/cid/ciw779. DOI: https://doi.org/10.1093/cid/ciw779

Hausner, M., & Wuertz, S. (1999). High rates of conjugation in bacterial biofilms as determined by quantitative in situ analysis. Applied and Environmental Microbiology, 65(8), 3710–3713. https://doi.org/10.1128/AEM.65.8.3710-3713.1999 DOI: https://doi.org/10.1128/AEM.65.8.3710-3713.1999

Kaplan, J. B. (2010). Biofilm dispersal: Mechanisms, clinical implications, and potential therapeutic uses. Journal of Dental Research, 89(3), 205–218. https://doi.org/10.1177/0022034509359403 DOI: https://doi.org/10.1177/0022034509359403

Mah, T. F., & O'Toole, G. A. (2001). Mechanisms of biofilm resistance to antimicrobial agents. Trends in Microbiology, 9(1), 34–39. https://doi.org/10.1016/S0966-842X(00)01913-2 DOI: https://doi.org/10.1016/S0966-842X(00)01913-2

Mathur, T., Singhal, S., Khan, S., Upadhyay, D. J., Fatma, T., & Rattan, A. (2006). Detection of biofilm formation among the clinical isolates of staphylococci: An evaluation of three different screening methods. Indian Journal of Medical Microbiology, 24(1), 25–29. https://doi.org/10.4103/0255-0857.19890 DOI: https://doi.org/10.1016/S0255-0857(21)02466-X

Mohamed, E. S., Ahmed, E. A., & Khalil, M. A. (2020). Prevalence of ESBL- and carbapenemase-producing Enterobacteriaceae in urinary tract infections in Egypt. Infection and Drug Resistance, 13, 3991–4002. https://doi.org/10.2147/IDR.S279830

Nicolle, L. E. (2019). Urinary tract infections in special populations: Diabetes, renal transplant, HIV infection, and spinal cord injury. Infectious Disease Clinics of North America, 33(3), 513–522. https://doi.org/10.1016/j.idc.2019.04.008

Okeke, I. N., Klugman, K. P., Bhutta, Z. A., Duse, A. G., Jenkins, P., O'Brien, T. F., Pablos-Mendez, A., & Laxminarayan, R. (2005). Antimicrobial resistance in developing countries. Part I: Recent trends and current status. The Lancet Infectious Diseases, 5(8), 481–493. https://doi.org/10.1016/S1473-3099(05)70189-4 DOI: https://doi.org/10.1016/S1473-3099(05)70189-4

Rashid, M., Gupta, N., Singh, R., Shukla, I., & Khan, R. N. (2016). Biofilm formation and antimicrobial resistance in uropathogenic Escherichia coli. Pathogens and Global Health, 110(6), 288–293. https://doi.org/10.1080/20477724.2016.1230570

Singh, R., Ray, P., Das, A., & Sharma, M. (2017). Penetration of antibiotics through Staphylococcus aureus and Staphylococcus epidermidis biofilms. Journal of Antimicrobial Chemotherapy, 72(1), 89–98. https://doi.org/10.1093/jac/dkw358 DOI: https://doi.org/10.1093/jac/dkw358

Tadesse, B. T., Ashley, E. A., Ongarello, S., Havumaki, J., Wijegoonewardena, M., González, I. J., & Dittrich, S. (2017). Antimicrobial resistance in Africa: A systematic review. BMC Infectious Diseases, 17, Article 616. https://doi.org/10.1186/s12879-017-2713-1 DOI: https://doi.org/10.1186/s12879-017-2713-1

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