مناقشة طالب دكتوراه من كلية العلوم


A Thesis
Submitted to the Council of the College of Science of Tikrit University as a Partial Fulfillment of the Requirements for the Degree of Doctor of Science Philosophy in Biology/Microbiology

M.Sc. College of Science/Biology/ Tikrit University 2009

Ibraheem Abudl Rahman Latif


Prof. Dr. Assist. Prof. Dr.
Abdulghani M. Alsamarai Mohammed M. Abdul-Aziz

مناقشة طالب دكتوراه من كلية العلوم

Urinary tract infection is a health growing problem globally and encountered at all ages and associated with treatment failure. Escherichia coli is the predominant pathogen which is causing urinary tract infection (UTI), the most common bacterial infectious disease encountered in clinical practice, accounting for significant morbidity and high medical costs. The severity of UTI produced by E. coli is due to the expression of a wide spectrum of virulence factors, ESBL E. coli producers prevalence increased worldwide and contributed to epidemiological changes in (UTI) pattern and interfere with management of urinary tract infection.

مناقشة طالب دكتوراه من كلية العلوم
In this study we evaluated role of E. coli virulence genes determinants in the pathogenesis of UTI, the predictive value of urine direct testing approaches (as a non-invasive and cost effective test for diagnosis of urinary tract infection especially in primary health care centers in which culture is not available) , determine the frequency ESBL producing E. coli and clarify their susceptibility to antibiotics.

مناقشة طالب دكتوراه من كلية العلوم
This study began in April 2015 and finished in March 2016. The patients with clinically diagnosed or suspected UTI were enrolled in this study. This study included different ages of males and females. A total of 500 urine samples were collected aseptically from out and inpatients admitted to Erbil Teaching-Hospital in Erbil City, 307 (61.4%) of females and 193 (38.6%) of males. Cultures (MacConkey and blood agar) and nonculture methods (Urine Gram stain, Nitrite , Leukocyte Esterase) for the laboratory diagnosis of UTI were done for all cases.
Bacterial isolates were identified, antibiotics susceptibility and ESBL were determined using VITEX 2 system. A total of 20 uropathogenic E. coli strains were screened by PCR for the prevalence of five virulence genes encoding type I pili (fimH), S fimbriae (sfa), P fimbriae (papC), uropathogenic specific protein (uspA) and cytotoxic necrotizing factor (cnf).

This study indicates that the incidence of UTI in Erbil City was 22%. The incidence was significantly higher in female as compared to male. E. coli was the predominantly (46.42%; 52/112) isolated from subjects with UTI, followed by Coagulase negative staphylococci (33.9%; 38/112), Klebsiella pneumonia (8.03%; 9/112), Enterobacter cloacae (5.35%;6/112), Serratia marcescens (4.46%; 5/112) and Acinetobacter baumannii (1.78%;2/112). Direct urine tests (Urine Gram stain, Nitrite and Leukocyte Esterase) show low sensitivity, but with high specificity and their combination may increase the sensitivity and specificity rate. All E. coli isolates were resistant to Ampicillin, Mezlocilin and Piperacillin, while all were sensitive to Ertapenem, Fosfomycin and Tigecycline, except one isolate was resistant to the all tested antibiotics. Although, this study shows that ESBL producing E. coli uropathogen isolates was high [61.5 %, 32/52], however, the rate was within the range reported globally. ESBL producing E. coli shows maximum resistance to Ampicillin, Cefazolin, Cefepime, Cefotaxime, Tetracycline, Mezlocilin, Piperacillin, Cefuroxime (100%) and ceftazidime (93.7%) while minimum resistance was to Ertapenem, Tigecycline, Fosfomycin (3.1%), Imipenem (6.2%) and Amikacin, Nitrofurantion (9.6%). ESBL producing E. coli was with higher rate of resistance as compared to ESBL negative E. coli.
Regarding virulence genes in E. coli, the most prevalent genes were adhesions genes, sfa (100%), papC (95%), uspA (90%) fimH (80%) and gene coding for toxin production cnf (95%).

مناقشة طالب دكتوراه من كلية العلوم

In conclusion, UTI incidence was low to that reported in other areas in Iraq and significantly more in females than in males. E. coli was the predominantly isolated from subjects with UTI, followed by Coagulase negative staphylococci. Rapid tests (non-cultured) are with predictive value in diagnosis of UTI when interpreted in combination. The high rate of ESBL E. coli producer's isolates is a community and nosocomial health problem that is associated with the emergence of antimicrobial resistance which is attributed to treatment failure of UTI and recurrent infections. This study demonstrated that virulence genes are common among E. coli strains causing urinary tract infection.

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