Genotypic Characterization of Antimicrobial Resistance-Associated Genes in Citrobacter Freundii Isolated from Patients with Urinary Tract Infection in Al-Najaf Governorate-Iraq

Citrobacter freundii is one of the most important pathogens that cause urinary tract infection in human because it harbors many types of antimicrobials resistance-associated genes. Therefore, this study aimed to evaluate the prevalence of antimicrobial resistance-associated genes citrobacter freundii isolated from patients with urinary tract infection in Al-Najaf governorate-Iraq. A total of 30 strains of citrobacter freundii isolated from urine samples of patients with urinary tract infection in Al-Najaf central hospital in Al-Najaf City, Iraq, during April to December 2018. Polymers chain reaction technique was used to detect the presence of antimicrobial resistance-associated genes. From the 30 strains of citrobacter freundii, 15 strains (50%) were positive for bla-tem gene, 16 strains (53.3%) were positive for bla-shv gene, 21 strains (70%) were positive for bla-ctxm gene, 3 strains (10%) were positive for bla-ctxm-1 gene, 6 strains (20%) were positive for bla-ctxm-2 gene. Interestingly, it should be noted that no any strain form the 30 we tested was carrying pse1, bla-ctxm-8, bla-ctxm-9 or bla-ctxm-25 genes. Our data showed that 19 strains (63.3%) were positive for cat1 gene, 9 strains (30%) were positive for cat2 gene and 4 strains (13.3%) were positive for cat3 gene. On the other hand, 17 strains (56.6%) were carrying qnrA gene, 11 strains (36.6%) were carrying qnrB gene and aac(6')-Ib-cr gene. Also, the results proved that there were 7 strains (23.3%) being positive for sul1 gene and 11 strains (36.6%) were positive for sul2 gene. We also found 22 strains (73.3%) being positive for strA-strB gene and 4 isolates (13.3%) were positive for aacC1 genes. No strain carrying aacC2, tetA and tetB genes was identified. Citrobacter freundii harbor large numbers of different antimicrobial resistance-associated genes that enable this pathogen to escape the effect of antibiotics which make this bacteria highly resistant causing urinary tract infection.