Genetic identification of potentially probiotic vaginal Lactobacillus strains isolated from Argentina

MARÍA SILVINA JUÁREZ TOMÁS; DANIELA ZONENSCHAIN; LORENZO MORELLI; MARÍA ELENA NADER-MACÍAS

Roma. Italia

Congreso; 2º Probiotics, Prebiotics & New Foods; 2003

Idea Congress Srl

Objetive. To identify genetically Lactobacillus strains isolated from human vagina, by the Amplified 16s rDNA Restriction Analysis (ARDRA). These strains, with good surface properties and antagonistic substances producers, were selected by their potential use in a probiotic product for vaginal application. Methods. ARDRA with four restriction enzimes (Sau 3AI, Hinf I, Dra I and Hinc II) was applied to twenty-three vaginal Lactobacillus isolates from Tucumán, Argentina. The results of genetic identification were compared with those previously obtained by phenotypic methods (API CH 50). Results. The genetic identification confirmed the phenotypic results at metabolic groups level (homofermentative and heterofermentative). However, at Lactobacillus species level, the genetic and phenotypic identifications only coincided in six strains (26%), belonging to the species: L. salivarius, L. reuteri, L. rhamnosus, and L. paracasei. The most of microorganisms phenotypically classified as L. acidophilus were L. gasseri. The restriction profiles of two strains, previously identified as L. crispatus, corresponded to L. acidophilus. The ARDRA from three L. delbrueckii strains allowed the identification of a strain as L. johnsonii, while the digestion patterns from the remaining strains were different from the available theoretical profiles.  Conclusions. The application of ARDRA allowed the rapid identification of twenty vaginal Lactobacillus strains, belonging to seven different species. The genetic identification of three remaining strains is even in course. The L. gasseri and L. rhamnosus were the predominant species from the twenty-three vaginal Lactobacillus strains evaluated in this work. The correct genetic identification is a fundamental requirement for those microorganisms with potential probiotic use.