ABSTRACT
Urinary tract infections [UTIs] are the most common cause of nosocomial infection and up to 80% of UTIs are associated with the use of urinary catheter. Inappropriate use of this device may lead to an increase incidence of infectious complications. It has been estimated that 65 % of nosocomial infections are biofilm associated urinary tract infections, loading the health care system enormous costs. These biofilm infections are 10 to 1000 times more resistant to the effects of antimicrobial agents. In this study urine samples were collected from 150 patients with CAUTI [group 1] giving one hundred and fifty bacterial isolates and 70 non catheterized UTI patients [group 2] giving fifty bacterial isolates. Out of the two hundred isolates the most common isolated pathogens were: Escherichia coli[E.coli] [50%] in group I, [48%] in group 2, followed by Klebsiella [26.7%] in group J, [28%] in group 2, pseudomonas aeruginosa [8%] in group 1, [12%] in group 2 then Staphylococcus aureus [8.6%] in group 1, [4.%] in group 2, Proteus [4.6%] in group 1, [4%] in group 2, and lastly, Candida albicans [2%] in group 1,[4. %] in group 2. The E.coli isolates were evaluated for biofilm formation using congo red agar [CRA] and microtitre plate methods. Out of 99 E.coli isolates; 27 were non biofilm forming in group 1, 19 isolates in group 2 while 48 isolates were biofilm forming in group 7, only 5 isolates in group 2 . Using microtitre plate method; out of 48 biofilm forming isolates in group 1; 8 isolates [16.6%] were weak biofilm forming, 10 [20.8%] were moderate biofilm and 30 isolates [62.5%] were strong biofilm forming while, 3 isolates were weak biofilm forming in group2. The two methods used to detect biofilm formation [CRA test and spectrophotometer], both are valid tests. CRA is simpler but spectrophotometer differentiates between weak and strong biofilm producers