Molecular and biochemical characterizations of human oral lactobacilli as putative probiotic candidates

• Published in: Oral microbiology and immunology 2007-04, Vol.22 (2), p.111-117
• Main Authors: Strahinic, I., Busarcevic, M., Pavlica, D., Milasin, J., Golic, N., Topisirovic, L.
• Format: Article
• Language: English
• Subjects: 16S rDNA; Adult; Antibiosis; Bacterial Typing Techniques; Biological and medical sciences; Candida albicans; Dental Caries - microbiology; Dentistry; DNA, Bacterial - analysis; DNA, Ribosomal - analysis; Enterococcus faecalis; Female; Fundamental and applied biological sciences. Psychology; Humans; Hydrogen-Ion Concentration; lactobacilli; Lactobacillus - chemistry; Lactobacillus - classification; Lactobacillus - genetics; Lactobacillus acidophilus; Lactobacillus cellobiosus; Lactobacillus delbrueckii; Lactobacillus fermentum; Lactobacillus gasseri; Lactobacillus paracasei; Lactobacillus plantarum; Lactobacillus salivarius; Male; Microbiology; Micrococcus flavus; Middle Aged; Mouth - microbiology; oral microflora; probiotic; Probiotics; repetitive sequence-based polymerase chain reaction; Repetitive Sequences, Nucleic Acid; Salmonella enteritidis; Sequence Analysis, DNA; Staphylococcus aureus; Streptococcus mutans; Streptococcus pneumoniae
• ISSN: 0902-0055; 1399-302X
• DOI: 10.1111/j.1399-302X.2007.00331.x

Introduction:  The objective of this study was to characterize the lactobacilli from the human oral cavity as a potential source of probiotic strains. Methods:  Samples were collected from four different locations within the oral cavity: surface of healthy tooth, oral mucous membrane, surface of tooth decay and deep tooth decay. On the basis of morphological and biochemical properties eight categories were formed and 26 isolates were selected for further characterization. The isolates were determined as Lactobacillus sp. using primers specific for 16S rDNA. Sequencing of 16S rDNA genes and repetitive sequence‐based polymerase chain reactions were used for determination to species and subspecies levels. Results:  Predominant species were Lactobacillus fermentum, Lactobacillus plantarum, Lactobacillus salivarius and Lactobacillus paracasei subsp. paracasei, while Lactobacillus acidophilus, Lactobacillus cellobiosus, Lactobacillus delbrueckii subsp. lactis and Lactobacillus gasseri were also present. The isolates Lactobacillus salivarius BGHO1, Lactobacillus fermentum BGHO36 and BGHO64, Lactobacillus gasseri BGHO89 and Lactobacillus delbrueckii subsp. lactis BGHO99 exhibited antagonistic action on the growth of Staphylococcus aureus, Enterococcus faecalis, Micrococcus flavus, Salmonella enteritidis, Streptococcus pneumoniae and Streptococcus mutans, but not on growth of Candida albicans. Moreover, the isolates L. salivarius BGHO1 and L. gasseri BGHO89 were tolerant to low pH and high concentration of bile salts. Conclusion:  Taken together, these findings imply that L. salivarius BGHO1 and L. gasseri BGHO89 might be subjects for additional investigation as potential probiotic strains.