A study on Quorum Sensing gene gen luxS and Mixed biofilm dynamics of Proteus mirabilis and Candida albicans in Urinary Tract Infections

Abstract

The role of biofilm formation is to act as protective defences to harbour bacteria, aids them to avoid the host immune system as well as the exposure to antibiotics. This is especially relevant to the case of urinary tract infections (UTIs), where biofilm forming bacteria causes recurring and persistent infection. This study was founded to identify the quorum- sensing gene luxS which is related to the formation of biofilm and to evaluate the antibiotic resistance profile of Proteus mirabilis, and finally to isolate Candida albicans yeast using urinary samples of women with UTIs. 270 midstream urine samples were obtained after collecting female patients aged 15 to 70 years at Kirkuk hospital, Kirkuk, Iraq, over the period April, to October, 2024. Culture was done on appropriate media after the samples were examined microscopically. Among the whole, 20 samples (7.4%) gave growth of bacteria that was characterised as Proteus. mirabilis and 30 isolated as Candida albicans. The results of an antibiotic susceptibility test were low sensitivity to ampicillin (20%), high sensitivity to vancomycin (80%), levofloxacin (90%), and total sensitivity (100%) to imipenem and amikacin. Eighty percent were positive in biofilm growth, i.e., 16 out of 20 isolates. In molecular analysis, 100 percent or all the 20 isolates had luxS gene which is involved in the production of signaling molecules in quorum sensing, and is given significant role in pathogenicity and biofilm. Such results imply that luxS gene is distributed widely among P. mirabilis isolates and can influence antibiotic resistance, thus being one of the targets in the future treatment strategies.