Table of Contents
ISRN Microbiology
Volume 2013 (2013), Article ID 342082, 6 pages
http://dx.doi.org/10.1155/2013/342082
Research Article

16S rRNA PCR-Denaturing Gradient Gel Electrophoresis of Oral Lactobacillus casei Group and Their Phenotypic Appearances

1Common Oral Diseases and Epidemiology Research Center, Faculty of Dentistry, Prince of Songkla University, Hat Yai 90112, Thailand
2Department of Preventive Dentistry, Faculty of Dentistry, Prince of Songkla University, Hat Yai 90112, Thailand
3Department of Stomatology, Faculty of Dentistry, Prince of Songkla University, Hat Yai 90112, Thailand

Received 29 June 2013; Accepted 25 August 2013

Academic Editors: O. Pepe and A. Sunna

Copyright © 2013 S. Piwat and R. Teanpaisan. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This study aimed to develop a 16S rRNA PCR-denaturing gradient gel electrophoresis (DGGE) to identify the species level of Lactobacillus casei group and to investigate their characteristics of acid production and inhibitory effect. PCR-DGGE has been developed based on the 16S rRNA gene, and a set of HDA-1-GC and HDA-2, designed at V2-V3 region, and another set of CARP-1-GC and CARP-2, designed at V1 region, have been used. The bacterial strains included L. casei ATCC 393, L. paracasei CCUG 32212, L. rhamnosus ATCC 7469, L. zeae CCUG 35515, and 46 clinical strains of L. casei/paracasei/rhamnosus. Inhibitory effect against Streptococcus mutans and acid production were examined. Results revealed that each type species strain and identified clinical isolate showed its own unique DGGE pattern using CARP1-GC and CARP2 primers. HDA1-GC and HDA2 primers could distinguish the strains of L. paracasei from L. casei. It was found that inhibitory effect of L. paracasei was stronger than L. casei and L. rhamnosus. The acid production of L. paracasei was lower than L. casei and L. rhamnosus. In conclusion, the technique has been proven to be able to differentiate between closely related species in L. casei group and thus provide reliable information of their phenotypic appearances.