Antifungal effects of Lactobacillus acidophilus and Lactobacillus plantarum against different oral Candida species isolated from HIV/ AIDS patients: an in vitro study

Abstract

Oropharyngeal Candidiasis (OPC) is an opportunistic fungal infection occurring in immunocompromised patients such as HIV/AIDS. The purpose of this study was to evaluate the antifungal properties of <i>Lactobacillus acidophilus</i> and <i>Lactobacillus plantarum</i> on different <i>Candida</i> species isolated from oral cavity of HIV/AIDS patients compared to Fluconazole (FLC). In this study, the antifungal effects of both cells and cell-free supernatants (CFSs) of <i>L. acidophilus</i> and <i>L. plantarum</i> were investigated against different oral <i>Candida</i> species by co-aggregation, agar overlay interference and broth microdilution assays, respectively. Our results showed that the highest co-aggregation ratio of the two tested Lactic acid bacteria (LAB) was observed for <i>C. krusei</i>. Both <i>L. acidophilus</i> and <i>L. plantarum</i> at cell concentrations 10¹⁰ to 10² cfu/ml were able to inhibit the growth of most of the oral <i>Candida</i> species, except for <i>C. albicans</i>, and to some <i>C. krusei</i>. In this study, MIC and MFC values for CFS of <i>L. acidophilus</i> ranged from 100 to 200 µl/ml and 100 to 200 µl/ml, respectively, and MIC and MFC values for CFS of <i>L. plantarum</i> were 50 to 200 µl/ml and 50 to 200 µl/ml, respectively. The ranges of MIC and MFC for FLC were 256-1024 µg/ml and 512-2048 µg/ml, respectively. <i>C. albicans</i> and <i>C. parapsilosis</i> displayed the highest and least susceptibility to CFSs of two LAB, respectively. Our findings showed that both cells and CFSs of <i>L. acidophilus</i> and <i>L. plantarum</i> had antifungal effects against oral <i>Candida</i> species.