Molecular Characterization of Biofilm Forming Enterococcus spp. Isolated from Patients with Catheter Associated Urinary Tract Infections

Abstract

Urinary tract infection associated with catheter is the most common healthcare infection which can lead to complications and death. The study was done to investigate the antibiotic resistance profile, biofilm formation and molecular characteristics of Enterococcus spp. isolated from patients with urinary tract infections associated with catheter. Two hundred and twenty (220) urine samples were collected from the catheter tubings / sampling ports of catheterized patients. The samples were inoculated on petri dishes containing blood agar and they were incubated at 370C for 24 hours. The isolated organisms were identified using gram staining and biochemical tests. Antibiotic susceptibility test was done using the disc diffusion method. Biofilm formation was evaluated using Congo Red Agar and PCR was used to detect the resistance genes of the organisms. After the analysis, it was observed that out of the 220 samples, 212 (96.36%) had Enterococcus spp. Also, 118 (56%) isolates out of the 212 isolates were identified as Enterococcus faecalis while 94 (44%) of them were Enterococcus faecium. It was also observed that there was higher prevalence of both Enterococcus faecalis and Enterococcus faecium in females (64.41%; 61.70%) than in males (35.59%; 38.29%). Highest prevalence of Enterococcus spp. (49.2%;47.9%) was seen in patients who were 60 years and above while the least prevalence (7.6%;6.4%) was seen in those who were 20 years and below. The antibiotic resistance pattern of Enterococcus faecalis and Enterococcus faecium observed in this study showed that Enterococcus faecium exhibited higher resistance to the tested antibiotics than Enterococcus faecalis. The virulence genes associated with multidrug resistance of the isolated organisms were found to be asa1, ge1E, esp. efaA and cy1A in Enterococcus faecium isolates and esp, hy1 and efaAfm in E. faecalis.  This confirms that E. faecium had greater multidrug resistant potential on catheter associated urinary tract infections and Enterococcus faecalis carried more virulence genes; asa1, ge1E and esp which were associated with adhesion and biofilm formation. The co-existence of multidrug resistance and virulence observed in both organisms isolated from those patients poses serious treatment challenge and this can lead to life threatening complications. Therefore, regular surveillance of antimicrobial resistance and virulence determinants are essential for effective infection control and management.