Antifungal and Antiadhesion Activities of Lactic Acid Bacteria Isolated from Honey against Candida Species

Candida species are recognized as one of the major cause of hospital-acquired infections.They have become resistance to many antifungal agents, there is a need to develop methods to inhibit the growth of pathogenic Candida spp.This study evaluated the ability of lactic acid bacteria against pathogenic Candida spp.Twenty five isolates of lactic acid bacteria (LAB) were isolated from honey samples from Malaysia,Libya, Saudi Arabia and Yemen, were evaluated for antifungal activity against five strains of pathogenic Candida species namely,C albicans ATCC 1405, C glabrata ATCC2001, C. tropicalis ATCC750,C. parapsilosis ATCC 22019 and C. krusei ATCC6258 using dual agar overlay method and well diffusion method.Four isolates of LAB showed good inhibitory activity against Candida spp. And were identified using API 50CHL nad 16SrDNA as Lactobacillus plantarum HS, Lactobacillus curvatus HH,Pediococcus acidilactici HC and Pediococcus pentosaceus HM. Heating the cell free supernatant (CFS) at 90 and 121°C resulted in growth reduction of most Candida spp. Especially growth of C.glabrata was significantly (p˂0.001) and complete inhibition by CFS of L.curvatus HH and P.pentosaceus HM.The antifungal activity of these CFS was active at Ph 3 to 5,but decreased at Ph 6.CFS of L. plantarum HS and P. pentosaceus HM lost their antifungal activity especially, against C.parapsilosis at PH 7.The antifungal activity of CFS L. plantarum HS was decreased when tested with proteinase K indicating that CFS contained protein-like antifungal compaouns but, the antifungal activity of CFS HC,HH and HM was not destroyed when treated with proteinase K. Treating CFS with RNase destroyed the antifungal activity of HC and HH against all Candida spp.The CFS produced by these LAB inhibited the adhesion of five Candida spp. Biofilm in pre-coating and co-incubation experiments.In pre-coating experiment CFS showed significantly (p˂0.05) higher anti-adhesion activity against C. glabrata and C. albicans by 79.4% and 61.1%, respectively.While in co-incubation experiment CFS had high anti-adhesion activity against all Candida spp.This study demonstrated that the cells and supernatants of L. plantarum HS,P. acidilactici HC, L curvatus HH and P. pentosaceus HM that were isolated from honey could be used to inhibit the growth of Candida spp. And decreased the biofilm formation by these pathogen.