Genotypic Detection of qnrA and qnrC Genes in Citrobacter koseri Isolated from Patients with Urinary Tract Infection

The urinary tract infection (UTI) is a prevalent infection that affects people of all ages. Bacterial agents are the most common causes of UTIs. Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and other staphylococcal species, Citrobacter freundii and Citrobacter koseri (C. koseri) account for a smaller number of infections. These pathogens are transported into the urinary tract from the colonic biotope into dysbacteriosis. Urine samples were randomly collected from 249 outpatients who were suspected of having UTIs. After genital cleaning, 10 mL of urine specimens were collected in a sterilized bowel. Then, the specimens were centrifuged at 2,000 rpm for 5 min and the residue was aerobically incubated with the broth infusion of brain flasks at 37°C for 24 h and then applied with a sterile ring onto blood agar plates and MacConkey agar (OxoidTM). Out of 249 urine samples, the results proved that there were 176 (70.7%) and 51(20.5%) gram-negative and gram-positive bacteria isolates, respectively. However, the results demonstrated that there were 22 (8.8%) urine samples with no growth. In addition, the results showed that eight various antimicrobials are used to treat C. koseri. In the current study, C. koseri was treated with eight different antimicrobial agents. The antimicrobial resistance rate for 7 isolates against Cefotaxime, Ceftriaxone, Ciprofloxacin, and Levofloxacin was high for 6 (85.71%) isolates. The results indicated that 6 and 5 isolates had 85.71% and 71.42% antimicrobial resistance against Ceftazidime and Levofloxacin, respectively. Whereas Gentamicin showed a moderate rate of resistance (4 isolates, 57.14%), and Amikacin resistance was found in 5 isolates, accounting for 28.57%. The bacterial isolates had a high susceptibility rate to Imipenem. The qnrA gene was found in 6 (85.71%) isolates. However, the recorded data demonstrated that there is no isolate carrying the qnrC gene. Among all pathogenic bacteria, C. koseri was the lowest causative agent of UTI in this study and was highly resistant to most antimicrobials except Imipenem, which was a good antibiotic with 100% sensitivity.