Mi-Ju Kim

Quantitative detection of pork in commercial meat products by TaqMan® real-time PCR assay targeting the mitochondrial D-loop region.

The TaqMan® real-time PCR assay using the mitochondrial D-loop region was developed for the quantitative detection of pork in processed meat products. The newly designed primers and probe specifically amplified pork without any cross-reactivity with non-target animal species. The limit of detection of the real-time PCR assay was 0.1pg of heat-treated pork meat and 0.1% (w/w) pork meat in beef and chicken meat mixtures. The quantitative real-time PCR assay was applied to analyze the pork meat content in 22 commercial processed meat products including jerkies, press hams, sausages, hamburger patties and steaks, grilled short rib patties, and nuggets. The developed real-time PCR method was able to detect pork meat in various types of processed meat products that declared the use of pork meat on their label. All processed meat products that declared no use of pork meat showed a negative result in the assay. The method developed in this study showed sensitivity and specificity in the quantification of pork meat in commercial processed meat products.

Development of a One-Step Duplex RT-PCR Method for the Simultaneous Detection of VP3/VP1 and VP1/P2B Regions of the Hepatitis A Virus.

The simultaneous detection and accurate identification of hepatitis A virus (HAV) is critical in food safety and epidemiological studies to prevent the spread of HAV outbreaks. Towards this goal, a one-step duplex reverse-transcription (RT)-PCR method was developed targeting the VP1/P2B and VP3/VP1 regions of the HAV genome for the qualitative detection of HAV. An HAV RT-qPCR standard curve was produced for the quantification of HAV RNA. The detection limit of the duplex RT-PCR method was 2.8 × 10(1) copies of HAV. The PCR products enabled HAV genotyping analysis through DNA sequencing, which can be applied for epidemiological investigations. The ability of this duplex RT-PCR method to detect HAV was evaluated with HAV-spiked samples of fresh lettuce, frozen strawberries, and oysters. The limit of detection of the one-step duplex RT-PCR for each food model was 9.4 × 10(2) copies/20 g fresh lettuce, 9.7 × 10(3) copies/20 g frozen strawberries, and 4.1 × 10(3) copies/1.5 g oysters. Use of a one-step duplex RT-PCR method has advantages such as shorter time, decreased cost, and decreased labor owing to the single amplification reaction instead of four amplifications necessary for nested RT-PCR.

Simultaneous Detection of Four Foodborne Viruses in Food Samples Using a One-Step Multiplex Reverse Transcription PCR

A one-step multiplex reverse transcription PCR (RT-PCR) method comprising six primer sets (for the detection of norovirus GI and GII, hepatitis A virus, rotavirus, and astrovirus) was developed to simultaneously detect four kinds of pathogenic viruses. The size of the PCR products for norovirus GI and GII, hepatitis A virus (VP3/VP1 and P2A regions), rotavirus, and astrovirus were 330, 164, 244, 198, 629, and 449 bp, respectively. The RT-PCR with the six primer sets showed specificity for the pathogenic viruses. The detection limit of the developed multiplex RT-PCR, as evaluated using serially diluted viral RNAs, was comparable to that of one-step single RT-PCR. Moreover, this multiplex RT-PCR was evaluated using food samples such as water, oysters, lettuce, and vegetable product. These food samples were artificially spiked with the four kinds of viruses in diverse combinations, and the spiked viruses in all food samples were detected successfully.

Development and validation of a multiplex PCR assay for simultaneous detection of chicken, turkey and duck in processed meat products

We developed a multiplex PCR assay for the efficient detection of chicken, turkey and duck meat. Three species-specific primer sets targeting 12S rRNA gene of turkey and mitochondrial cytochrome b (CYTB) gene of chicken and duck were selected. A universal primer pair targeting 18S rRNA gene was additionally used as a positive control. PCR product sizes for endogenous control, chicken, turkey and duck were confirmed to be 99 bp, 133 bp, 163 bp and 204 bp respectively. The specificity of each primer pairs was evaluated in 20 animal species. The limit of detection of this multiplex PCR assay was 1 pg for all species. Furthermore, this method was successfully applied to 31 commercial meat samples and validated at intralaboratory. This multiplex PCR assay for the simultaneous identification of chicken, turkey and duck meat in processed products can be utilised to monitor various processed food products for food control and regulation.

Draft Genome Sequence of Pediococcus pentosaceus Strain FBL2, a Probiotic Bacterium Isolated from Jogaejeot, a Salted Fermented Food, in the Republic of Korea

ABSTRACT Pediococcus pentosaceus strain FBL2 is a lactic acid bacterium isolated in the Republic of Korea from jogaejeot, a salted fermented food made with shellfish. P. pentosaceus strain FBL2 comprised 54 contigs (≥1 kb) and had a total draft genome size of 1,934,229 bp with a G+C content of 37.2%.