Molecular characterization of Dr/Afa genes prevalent among multi drug resistant Escherichia coli isolated from urinary tract infections


  • Asmaa Samir Mohsin Department of Biology, College of Science, Mustansiriyah University, Baghdad, Iraq
  • Ali Haider Alsakini Department of Biology, College of Science, Mustansiriyah University, Baghdad, Iraq
  • Munim Radwan Ali Department of Biology, College of Science, Mustansiriyah University, Baghdad, Iraq



Recurrent UTIs; uropathogenic E. coli (UPEC); afimbrial adhesions; Dr/Afa genes; drug resistance.


Introduction and Aim: Escherichia coli strains are derived from several phylogenetic groups and have an array of virulence factors such as fimbrial adhesins, which are expressed by the Dr/Afa gene clusters and contribute to overcoming diverse defense mechanisms, resist drugs, and causing disease. The study sought to ascertain the prevalence of the Dr/Afa genes and resistance patterns among E. coli isolated from patients suffering from recurrent urinary tract infections. 

Materials and Methods: In this prospective cross-sectional study, a maximum of 500 mid-stream urine samples were collected from UTI patients identified at medical centers in Baghdad, Iraq. Antimicrobial susceptibility tests and polymerase chain reaction were used to determine the resistance pattern and gene distribution among isolates, respectively, as well as biochemical tests to diagnose isolates.  

Results: Research data revealed that recurrent urinary tract infections were associated with the pathogen E. coli (43.88%), followed by Klebsiella pneumoniae (12.82%). The results demonstrated significant antibiotic resistance patterns among isolates associated with recurrent UTIs and the most common antibiotic resistance was observed with penicillin (81.4%), followed by 81 (68.6%) sulfonamides and 63 (53.4%) fluoroquinolones. Molecular studies of the Dr/Afa operon using polymerase chain reaction, revealed several genotypes for genes within the operon. Among isolates studied the prevalence of the gene draA gene was 62 (52.5%), draB 41 (34.7%), draC 66 (55.9%), draD 65 (55.1%), draE 64 (54.2%), and draP 95 (80.5%). Furthermore, XDR and MDR-resistant phenotypes were significantly prevalent in isolates harboring hetero Dr/Afa fimbriae.

Conclusion: The results of this study indicate an inverse correlation between the presence of antibiotic resistance patterns and the prevalence of Dr/Afa genes wherein, the isolates with fewer fimbrial adhesion genes were found to be highly resistant. This study implies the Dr/Afa genes involvement in developing UTIs, suggesting that they might be associated with antibiotic resistance and  recurrent UTIs.


Dadi, B. R., Abebe, T., Zhang, L., Mihret, A., Abebe, W., Amogne, W. Distribution of virulence genes and phylogenetics of uropathogenic Escherichia coli among urinary tract infection patients in Addis Ababa, Ethiopia; BMC Infectious Diseases. 2020; 20(1): 108.

Sabitha, B., Karnake, V.K., Geetha, R. K. Adhesins of uropathogenic Escherichia coli (UPEC). International Journal of Medical Microbiology and Tropical Diseases. 2016;2(1): 10-18.

Ali, M.R., Khudhair, A. M. Detection of colony adhesion factors and genetic background of adhesion genes among multidrug-resistant uropathogenic Escherichia coli Isolated in Iraq. Journal of Pure and Applied Microbiology. 2018; 12(4): 2017.

Servin, A. L. Pathogenesis of Afa/Dr diffusely adhering Escherichia coli. Clinical microbiology reviews. 2005;18(2): 264-292.

Peiffer, I., Blanc-Potard, A.B., Bernet-Camard, M.F., Guignot, J., Barbat, A., et al., Afa/Dr diffusely adhering Escherichia coli C1845 infection promotes selective injuries in the junctional domain of polarized human intestinal Caco-2/TC7 cells; Infect. Immun.2000; 68:3431-3442.

Servin, A.L. Pathogenesis of human diffusely adhering Escherichia coli expressing Afa/Dr adhesins (Afa/Dr DAEC): current insights and future challenges; Clin. Microbiol Rev. 2014; 27(4):823-869.

Scholes, D., Hooton, T. M., Roberts, P. L., Gupta, K., Stapleton, A. E., Stamm, W. E. Risk factors associated with acute pyelonephritis in healthy women. Annals of Internal Medicine. 2005;142(1): 20-27.

Kansau, I., Berger, C., Hospital, M., Amsellem, R., Nicolas, V., Servin, A.L., et al., Zipper-like internalization of Dr-positive Escherichia coli by epithelial cells is preceded by an adhesion -induced mobilization of raft-associated molecules in the initial step of adhesion; Infect Immun. 2004;72:3733- 3734.

Magiorakos, A.P., Srinivasan, A., Carey, R.B., Carmeli, Y., Falagas, M.E., Giske, C.G., et al., Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance; Clin Microbiol Infect. 2012;18(3):268-281.

Depardieu, F., Podglajen, I., Leclercq, R., Collatz, E., Courvalin, P. Modes and modulations of antibiotic resistance gene expression; Clin. Microbiol. Rev.2007; 20:79-114.

Zalewska-Piatek, B.M. Urinary tract infections of Escherichia coli strains of chaperone-usher system; Pol. J. Microbiol. 2011; 60:279-285.

Robins-Browne, R. M., Bordun, A. M., Tauschek, M., Bennett-Wood, V. R., Russell, J., Oppedisano, F., et al., Escherichia coli and community-acquired gastroenteritis, Melbourne, Australia; Emerging infectious diseases.2004; 10(10): 1797-1805.

Tewawong, N., Kowaboot, S., Pimainog, Y., Watanagul, N., Thongmee, T., Poovorawan, Y. Distribution of phylogenetic groups, adhesin genes, biofilm formation, and antimicrobial resistance of uropathogenic Escherichia coli isolated from hospitalized patients in Thailand; PeerJ. 2020; 8: e10453.

Derakhshandeh, A., Firouzi, R., Moatamedifar, M., Motamedi, A., Bahadori, M., Naziri, Z. Phylogenetic analysis of Escherichia coli strains isolated from human samples. Molecular Biology Research Communications. 2013; 2(4): 143-149.

Clermont, O., Christenson, J.K., Denamur, E., Gordon, D.M. The Clermont Escherichia coli phylo-typing method revisited: improvement of specificity and detection of new phylo-groups; Environ Microbiol Rep. 2013; 5(1):58-65.

Ahumada-Cota, R.E., Hernandez-Chiñas, U., Milián-Suazo, F., Chávez-Berrocal, M.E., Navarro-Ocaña, A., Martínez-Gómez, D., et al., Effect and Analysis of Bacterial Lysates for the Treatment of Recurrent Urinary Tract Infections in Adults; Pathogens. 2020; 9(2):102.

Hernández-Chiñas, U., Chávez-Berrocal, M.E., Ahumada-Cota, R.E., Navarro-Ocaña, A., Rocha-Ramírez, L.M., Pérez-Del Mazo, Y., et al., Prospective study in children with complicated urinary tract infection treated with autologous bacterial lysates; Microorganisms. 2021; 9(9):1811.

Shimada, K. Editorial comment to circumcision related to urinary tract infections; Sexual transmitted infections, human immunodeficiency virus infection S, and penile and cervical cancer; Int J Urol. 2013; 20: 775-776.

Ejrnæs, K. Bacterial characteristics of importance for recurrent urinary tract infections caused by Escherichia coli. Dan Med Bull. 2011; 58(4): B4187.

Al-naimi, I.A., Abbas, M.A. Recurrent Urinary Tract Infections in Iraqi leukemic patients; International Journal of Advanced Research. 2016; 4(3): 1433-1439.

Khoshbakht, R., Salimi, A., Shirzad, H.A., Keshavarzi, H. Antibiotic susceptibility of bacterial strains isolated from urinary tract infections in Karaj, Iran; Jundishapur J Microbiol. 2013;6(1):86-90.

Alhamdany, M.H.A. Antibiotic susceptibility of bacteria isolated from patients with diabetes mellitus and recurrent urinary tract infections in Babylon Province, Iraq. Medical Journal of Babylon. 2018; 15(1): 63-68.

Shetty, A., Kumar, S., Shekar, M., Shetty, A., Karunasagar, I. Prevalence of adhesive genes among uropathogenic Escherichia coli strains isolated from patients with urinary tract infection in Mangalore. Indian J Med Microbiol. 2014;32(2):175.

Le Bouguénec, C., Lalioui, L., du Merle, L., Jouve, M., Courcoux, P., Bouzari, S., et al., Characterization of AfaE adhesins produced by extraintestinal and intestinal human Escherichia coli isolates: PCR assays for detection of Afa adhesins that do or do not recognize Dr blood group antigens; J Clin Microbiol. 2001;39(5):1738-1745.

Blango, M. G., Ott, E. M., Erman, A., Veranic, P., Mulvey, M.A. Forced resurgence and targeting of intracellular uropathogenic Escherichia coli reservoirs; PloS one. 2014; 9(3): e93327.




How to Cite

Asmaa Samir Mohsin, Haider Alsakini A, Munim Radwan Ali. Molecular characterization of Dr/Afa genes prevalent among multi drug resistant Escherichia coli isolated from urinary tract infections. Biomedicine [Internet]. 2022 Jul. 3 [cited 2023 Mar. 21];42(3):523-9. Available from:



Original Research Articles

Plum Analytics