An assessment of adhesion, aggregation and surface charges of Lactobacillus strains derived from the human oral cavity.
There is limited information concerning the adhesion and aggregation of human oral lactobacilli. In this study, the adhesion of 10 Lactobacillus species was investigated using H357 oral keratinocyte cells as an in vitro model for oral mucosa. Coaggregation with the representative oral pathogen, Streptococcus mutans ATCC 25175, and the physicochemical cell properties was also evaluated. The results demonstrated significant variations in adhesion (42-96%) and aggregation (autoaggregation, 14-95%; coaggregation, 19-65%). All strains showed a high affinity for chloroform, and most strains had a moderate-to-high hydrophobicity. All strains, except Lactobacillus casei and Lactobacillus gasseri, showed a moderate affinity for ethyl acetate. There was a strong association of autoaggregation with coaggregation (rs = 0·883, P < 0·001). The highest mean for autoaggregation (74%) and coaggregation (47%) belonged to the Lact. gasseri strains. Correlations between the adhesion and surface characteristics and aggregation were observed among the Lactobacillus fermentum and Lactobacillus paracasei strains; however, there was a variation in the strains properties within and between species. This study indicated that the Lact. gasseri, Lact. fermentum, and Lact. paracasei strains might be potential probiotics for the human oral cavity given their desirable properties. It should also be emphasized that a selective process for probiotic strains is required.


CONCLUSIONS
Adhesion to host tissues and bacterial aggregation (auto- and coaggregation) are the highly important criteria for selecting strains with probiotic potential. These abilities are commonly involved with surface-charged characteristics. This is the first study to investigate the oral Lactobacillus species using an oral keratinocyte cell line. Significant results were found for the correlations between the adhesion and surface charge characteristics and for aggregation among certain strains of Lactobacillus gasseri, Lactobacillus fermentum and Lactobacillus paracasei. This observation could be useful when collecting background information for the selection of probiotic strains for use in oral health.
Common Oral Diseases and Epidemiology Research Center, Faculty of Dentistry, Prince of Songkla University, Hat-Yai, Thailand.|Department of Preventive Dentistry, Faculty of Dentistry, Prince of Songkla University, Hat-Yai, Thailand.
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S
Piwat
Common Oral Diseases and Epidemiology Research Center, Faculty of Dentistry, Prince of Songkla University, Hat-Yai, Thailand.|Department of Stomatology, Faculty of Dentistry, Prince of Songkla University, Hat-Yai, Thailand.
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B
Sophatha
Common Oral Diseases and Epidemiology Research Center, Faculty of Dentistry, Prince of Songkla University, Hat-Yai, Thailand.|Department of Stomatology, Faculty of Dentistry, Prince of Songkla University, Hat-Yai, Thailand.
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Teanpaisan
D001422:Bacterial Adhesion / Q000502:physiology*; D002460:Cell Line; D002725:Chloroform / Q000494:pharmacology; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D015603:Keratinocytes / Q000382:microbiology / Q000502:physiology; D007778:Lactobacillus / Q000502:physiology*; D009055:Mouth / Q000382:microbiology*; D019936:Probiotics / Q000627:therapeutic use; D013295:Streptococcus mutans / Q000502:physiology
D002725:Chloroform
Lactobacillus strains; adhesion; aggregation; oral keratinocyte H357 cell; physicochemical properties