Abstracto

Lactobacillus Acidophilus la-5 Inhibits Growth and Biofilm Formation of Methicillin Resistant Staphylococcus aureus Isolated from Wounds of Hospitalized Patients

Salahuddin Khan and Salma Mahmud

The aim of the present study was to assess the ability of predominantly used probiotic strain Lactobacillus acidophilus La-5 to inhibit the growth and biofilm formation by Methicillin Resistant clinical isolates of S. aureus. A total of 41 clinical isolates of S. aureus were collected from wound samples of patients. Biofilm formation assay was performed using microtiter plate. At 24h incubation, 13 (31.70%, P<0.5) of the clinical isolates were strongly adherent, 25 (60.97%, P<0.5) were moderately adherent and only 3 (7.31%, P<0.5) were weakly adherent. Agar overlay interference test was employed to study the ability of L. acidophilus La-5 to inhibit the growth of S. aureus. The growth was completely inhibited at higher cell concentrations of L. acidophilus (107- 109). The inhibitory effects declined with lowering of cell concentration. The assay to study the inhibition of biofilm formation was conducted using microtiter plate and staining with crystal violet. Only 5 of the 13 strong biofilm producers were able to form biofilm upon introduction of probiotic strain. There were only 6 out of 25 moderate biofilm producers and none of the three weak biofilm formers were able to form biofilm upon co-inoculation with L. acidophilus La-5.