Abstract

Bacterial biofilms forming on indwelling urinary catheters continue to represent a public health problem because they are associated with urinary tract infections (UTIs). This study was undertaken to evaluate the ability of immobilized Lactobacillus acidophilus cells to inhibit biofilm formation on catheter surfaces. Urine bacteria and Lactobacillus species were isolated from urine and vaginal swabs (HVS), respectively. Immobilization of L. acidophilus on catheter samples was achieved using sodium alginate and the inhibition of urine bacteria by the immobilized Lactobacillus cells was evaluated by microscopy and viable cell count procedures following co-culture of the immobilized cells and urine bacteria. Results showed that pre-coating of catheter surfaces with L. acidophilus before exposure to urine bacteria significantly (p<0.05) reduced attachment of some urine bacteria to the catheter surfaces. Staphylococcus aureus, Klebsiella and Escherichia coli were significantly inhibited, while Pseudomonas aeruginosa was not inhibited. Furthermore, crude bacteriocin preparations from the Lactobacillus cells had antimicrobial activity against the urine bacteria. This study shows that pre-coating of catheter surfaces with L. acidophilus could be an effective strategy for controlling biofilm formation on urinary catheters.

Key words: Biofilm, catheter, Lactobacillus, immobilization, sodium alginate.