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Aims: To characterize in vitro the ability of human Lactobacillus strains to inhibit the adhesion, to displace and to compete with clinically isolated Candida strains., Methods and Results: Three types of assays were performed to determine the inhibitory effect of Lactobacillus plantarum 319, Lactobacillus rhamnosus IMC 501, Lactobacillus paracasei IMC 502 and a specific probiotic combination (SYNBIO) on adhesion of Candida pathogens to HeLa cells: blockage by exclusion (lactobacilli and HeLa followed by pathogens), competition (lactobacilli, HeLa and pathogens together) and displacement (pathogens and HeLa followed by the addition of lactobacilli). Bacterial adhesion to HeLa was quantified by microscopy after May-Grünwald/Giemsa stain. The inhibition results highlight a significant (P < 0·05) competition of the considered probiotics against all the Candida strains. The results suggest that the probiotic strains used in this study could prevent colonization of the urogenital tract by relevant pathogens such as Candida strains through barrier and interference mechanisms (mainly displacement and competition), but the degree of inhibition of adhesion was bacterial strain-dependent., Conclusions: The results support the potential of these Lactobacillus probiotic strains as anti-infective agents in the vagina and encourage further studies about their capacity to prevent and manage urogenital tract infections in females., Significance and Impact of the Study: To optimize the defensive properties of the vaginal microbiota, improving the health of many women by probiotic intervention., (© 2015 The Society for Applied Microbiology.)

Aims Probiotic lactobacilli have a great potential to produce antimicrobial compounds that inhibit and control the microbial pathogen growth. The antimicrobial and antifungal activities of two probiotic strains, Lactobacillus rhamnosus IMC 501® and Lactobacillus paracasei IMC 502®, and their 1 : 1 combination, named SYNBIO®, were studied using four different methods. Methods and Results Using two modified streak methods and a well diffusion method, the inhibitory activity of the probiotics and their metabolites towards six Gram-positive, nine Gram-negative pathogenic bacterial strains and eight Candida strains was tested. Antagonistic effect of probiotic Lactobacillus strains was also investigated by coculturing assay highlighting a significant inhibition of most of the pathogens tested in this study. The combination SYNBIO® showed a microbicidal activity against most of the strains tested in the study. Conclusions Compared with the control, most of the pathogenic bacteria and yeast were inhibited by all probiotic strains tested to various degrees. Significance and Impact of the Study Screening Lactobacillus strains according to their activity in various environmental conditions could precede the clinical efficacy studies for adjunct treatment with probiotics in cure of different gastrointestinal and vaginal tract infections. [ABSTRACT FROM AUTHOR]

Aims To test different Lactobacillus strains for their antipathogenic activity towards Candida strains and their adhesion properties for the preparation of vaginal ovules and douches to be used in vaginal candidiasis prevention. Methods and Results Five strains of lactobacilli were tested for their antimicrobial potential against different clinically isolated Candida strains. They were also screened for their ability to produce hydrogen peroxide and to coaggregate with pathogens. Adhesion properties of the five different Lactobacillus strains to HeLa cells and the presence of arcA gene were also assessed. The in vitro experiments demonstrated that all the five Lactobacillus strains tested possessed inhibitory action against the Candida strains using the radial streak method, but the effect is strain dependent. The same situation arises with regard to the ability of coaggregation that is present in all the strains into different degrees. Only Lactobacillus rhamnosus IMC 501® and Lactobacillus paracasei IMC 502® were able to produce H2 O2 and none of the strains possess arcA gene. The most adherent strains to He La cells were Lact. rhamnosus IMC 501®, Lact. paracasei IMC 502® and also their combination SYNBIO®. This latter was selected for the preparation of ovules and douches using different matrix. Witepsol® ovules have proved the best formulation in terms of probiotic viability. Conclusions Lactobacillus rhamnosus IMC 501®, Lact. paracasei IMC 502® and SYNBIO® were able to produce H2 O2, to coaggregate and to exert antimicrobial activity against pathogenic Candida strains and to strongly adhere to He La cells. All these properties together with those technological make these strains good candidates for the realization of formulations suitable for vaginal health. Significance and Impact of the Study To develop new vaginal formulations taking into account the impact of probiotic strains on pathogens as well as the technological properties of the strains to validate their effectiveness in human health. [ABSTRACT FROM AUTHOR]