Antimicrobial and Antibiofilm Activities of Probiotic Lactobacilli on Antibiotic-Resistant .

The emergence of biofilm-forming, multi-drug-resistant (MDR) infections is a serious threat that necessitates non-antibiotic therapies. Antibiotic susceptibility and biofilm-forming activity of isolates from urine samples were assessed by disc diffusion and crystal violet assays, respectively. Antimicrobial activities of probiotic by crystal violet assays. While most isolates were antibiotic-resistant to varying degrees, isolate P14 was MDR (resistant to ceftazidime, cefotaxime, amoxicillin-clavulanic acid, imipenem, ciprofloxacin, and amikacin) and formed strong biofilms. Cultures and cell-free supernatants of and exhibited antimicrobial and antibiofilm activities. The 1/16 concentration of untreated supernatants of and significantly reduced mature biofilm formation and adherence of P14 by 60% and 72%, respectively (for ), and by 73% each (for ). The 1/8 concentration of pH-adjusted supernatants of and significantly reduced mature biofilm formation and adherence of P14 by 39% and 75%, respectively (for ), and by 73% each (for ). Scanning electron microscopy (SEM) confirmed eradication of P14's biofilm by . and could be utilized to combat -associated urinary tract infections.