This study aimed to develop strain-specific polymerase chain reaction (PCR) primers to detect Fusobacterium hwasookii KCOM 1249T, F. hwasookii KCOM 1253, F. hwasookii KCOM 1256, F. hwasookii KCOM 1258, and F. hwasookii KCOM 1268 on the basis of nucleotide sequences of a gene specific to each strain. The unique genes for each F. hwasookii strain were determined on the basis of their genome sequences using Roary. The strain-specific PCR primers based on each strain-specific gene were designed using PrimerSelect. The specificity of each PCR primer was determined using the genomic DNA of the 5 F. hwasookii strains and 25 strains of oral bacterial species. The detection limit and sensitivity of each strain-specific PCR primer pair were determined using the genomic DNA of each target strain. The results showed that the strain-specific PCR primers correspond to F. hwasookii KCOM 1249T, F. hwasookii KCOM 1253, F. hwasookii KCOM 1258, F. hwasookii KCOM 1256/F. nucleatum subsp. polymorphum KCOM 1260, or F. hwasookii KCOM 1268/Fusobacterium sp. oral taxon 203 were developed. The detection limits of these strain-specific PCR primers ranged from 0.2 to 2 ng of genomic DNA for each target strain. The results suggest that these strain-specific PCR primers are valuable in quality control for detecting specific F. hwasookii strains.

This study aimed to develop Lautropia mirabilis -specific quantitative real-time polymerase chain reaction (qPCR) primers based on the sequence of DNA-directed RNA polymerase subunit beta gene. The PrimerSelect program was used in designing of the qPCR primers, RTLam-F4 and RTLam-R3. The specificity of the qPCR primers were performed by conventional PCR with 37 strains of 37 oral bacterial species, including L. mirabilis . The sensitivity of the primers was determined by qPCR with the serial dilution of purified genomic DNA of L. mirabilis KCOM 3484, ranged from 4 ng to 4 fg. The data showed that the qPCR primers could detect only L. mirabilis strains and as little as 40 fg of genome DNA of L. mirabilis KCOM 3484. These results indicate that this qPCR primer pair (RTLam-F4/ RTLam-R3) may be useful for species-specific detection of L. mirabilis in epidemiological studies of oral bacterial infectious diseases such as periodontal disease.

The purpose of this study was to develop Peptoniphilus mikwangii -specific quantitative real-time polymerase chain reaction (qPCR) primers based on the 16S ribosomal RNA (16S rDNA) gene. The specificity of the primers was determined by conventional PCR using 29 strains of 27 oral bacterial species including P. mikwangii. The sensitivity of the primers was determined by qPCR using the purified genomic DNA of P. mikwangii KCOM 1628T (40 ng to 4 fg). The data showed that the qPCR primers (RTB134-F4/RTB134-R4) could detect P. mikwangii strains exclusively and as little as 40 fg of the genomic DNA of P. mikwangii KCOM 1628T. These results suggest that the developed qPCR primer pair can be useful for detecting P. mikwangii in epidemiological studies of oral bacterial infectious diseases.

Salmonellosis is one of the most common food-borne diseases in both humans and animals. The recovery of Salmonella from fecal and environmental samples by bacteriological assays takes several days. Polymerase chain reaction (PCR) has become an important technique for the rapid detection of Salmonella in a variety of samples, including feces. For rapid identification of Salmonella by PCR, 1 mL of enrichment culture was harvested after overnight incubation and DNA was extracted by heat lysis. To investigate the optimal conditions for rapid PCR detection of Salmonella, three different primer sets and three different enrichment media were used on a panel of Salmonella strains and a panel of non-Salmonella strains. The results showed that selenite cysteine enrichment broth and a primer set designed for the invA gene provided the most specific and rapid detection of Salmonella by PCR after the enrichment step.