fimH and papC Genes Detection in Uropathogenic Escherichia coli and its Association with Biofilm Formation in Catheterized Patients
SUMMARY
Urinary tract infection (UTI) is one of the greatest widely recognized bacterial infection worldwide. Uropathogenic Escherichia coli (UPEC) is one of the main causative agents for nosocomial UTI. The microbial biofilms cause a public health problem to human who acquired indwelling medical devices such as a urinary catheter. The pathogens in biofilms are defended from unfavorable conditions, antibiotic therapies, and the host’s immune system.
The aim of the present study was to detect biofilm producer isolates, find out the correlation between biofilm formation and virulence associated genes, and determination of antimicrobial susceptibility pattern of Escherichia coli strains isolated from the catheterized patients.
In this study, 43 isolates of Escherichia coli were examined out of 211 urine specimens collected from catheterized patients at three hospitals (Rzgari Hospital, West Emergency Hospital, and Republic Teaching Hospital) in Erbil city during 25th of March to 23rd of July 2018. Data analysis was performed using Graph pad prism program version 7. Nonlinear regressions used to clarify the minimal inhibitory concentration, and non-parametric t-test (Mann-Whitney) test used to compare the susceptibility of the planktonic and the biofilm growth state. The level of significance was set at p < 0.05.
All isolates were 100% biofilm producers using 96-well flat bottomed polystyrene microtiter plate method. Also, molecular detection of uspA gene was performed as a species-specific PCR based marker for molecular identification of E. coli. Type 1 fimbriae fimH and pyelonephritis-associated pili papC genes were detected in 100% and 79% of the isolates respectively, as two adhesion genes responsible for biofilm formation. Minimal inhibitory concentrations (MIC50 and MIC90) were explained as the lowest concentration of antimicrobials, which show 50% and 90% inhibition of planktonic form and (BIC50 and BIC90) were biofilm inhibitory concentration. All isolates were 100% resistant to Ceftriaxone, Ciprofloxacin, Levofloxacin, and Cotrimoxazole, while the most effective antimicrobial agent used in the current study was Nitrofurantoin. Furthermore, most isolates in the biofilm form were more resistant to antimicrobial agents than those of the free-floating form. Additionally, there was a positive relationship between the adhesion genes and the capability to produce biofilm in UPEC.