• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.51 no.5
• /
• pp.518-523
• /
• 2018

This study analyzed the food safety in processing process of simple-processed fishery products. A total of 88 samples analyzed for the presence of pathogenic bacteria and physicochemical hazards. No major foodborne pathogenic bacteria, such as Salmonella sp., Listeria monocytogenes and Escherichia coli O157:H7, were detected in any of the samples. However, Bacillus cereus (12 samples, 13.6%) and Staphylococcus aureus (15 samples, 17.0%) were frequently detected in both the intermediate processing stages and the final products, although cell populations were not high. Very small amounts of heavy metals and histamine were detected in some samples, in quantities that did not exceed the safe guidelines according to Korean Government regulations. Similarly, no other physical hazards such as foreign material were observed in any of the samples. We concluded that there are no significant pathogenic bacteria or physicochemical food hazards in simply processed fish products from Korea. The present study strongly suggests that increased food sanitation measures should be implemented to decrease the prevalence of S. aureus in simple-processed fishery products.

• Korean Journal of Food Science and Technology
• /
• v.37 no.6
• /
• pp.1005-1011
• /
• 2005

Widespread distributions of repetitive DNA elements in bacteria genomes are useful for analysis of genomes and should be exploited to differentiate food-borne pathogenic bacteria among and within species. Enterobacterial repetitive intergenic consensus (ERIC) sequence has been used for ERIC-PCR genomic fingerprinting to identify and differentiate bacterial strains from various environmental sources. ERIC-PCH genomic fingerprinting was applied to detect and differentiate four major Gram-negative food-borne bacterial pathogens, Esherichia coli, Salmonella, Shigella, and Vibrio. Target DNA fragments of pathogens were amplified by ERIC-PCR reactions. Dendrograms of subsequent PCR fingerprinting patterns for each strain were constructed, through which relative similarity coefficients or genetic distances between different strains were obtained numerically. Numerical comparisons revealed ERIC-PCR genotyping is effective for differentiation of strains among and within species of food-borne bacterial pathogens, showing ERIC-PCR fingerprinting methods can be utilized to differentiate isolates from outbreak and to determine their clonal relationships among outbreaks.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.3
• /
• pp.307-314
• /
• 2016

Cheese is generally considered a safe and nutritious food, but foodborne illnesses linked to cheese consumption have occurred in many countries. Several microbial risk assessments related to Listeria monocytogenes, Staphylococcus aureus, and Escherichia coli infections, causing cheese-related foodborne illnesses, have been conducted. Although the assessments of microbial risk in soft and low moisture cheeses such as semi-hard and hard cheeses have been accomplished, it has been more focused on the correlations between pathogenic bacteria and soft cheese, because cheese-associated foodborne illnesses have been attributed to the consumption of soft cheeses. As a part of this microbial risk assessment, predictive models have been developed to describe the relationship between several factors (pH, Aw, starter culture, and time) and the fates of foodborne pathogens in cheese. Predictions from these studies have been used for microbial risk assessment as a part of exposure assessment. These microbial risk assessments have identified that risk increased in cheese with high moisture content, especially for raw milk cheese, but the risk can be reduced by preharvest and postharvest preventions. For accurate quantitative microbial risk assessment, more data including interventions such as curd cooking conditions (temperature and time) and ripening period should be available for predictive models developed with cheese, cheese consumption amounts and cheese intake frequency data as well as more dose-response models.

• Food Quality and Culture
• /
• v.3 no.1
• /
• pp.34-39
• /
• 2009

This study assessed the efficacy of aqueous chlorine dioxide ($ClO_2$) and commercial chlorine sanitizer in terms of its ability to eliminate Listeria monocytogenes, Salmonella Typhimurium, and Escherichia coli O157:H7 on radish sprouts (Raphanus sativus L.). Radish sprouts were inoculated with a cocktail containing one each of three strains of three different foodborne pathogens, then treated with distilled water (control) or chemical sanitizers (100 ppm commercial chlorine, and 50, 100, 200 ppm $C1O_2$) for 1, 5, and 10 min at room temperature ($22{\pm}2^{\circ}C$). Populations of S. Typhimurium, E. coli O157:H7 and L. monocytogenes were counted at 4.64, 6.05, and 4.29 log CFU/g, respectively, after inoculation. Treatment with water did not significantly reduce the levels of any of the three foodborne pathogens. The levels of all three pathogens were reduced by treatment with chemical sanitizers; however, the observed levels of reduction of E. coli O157:H7 and L. monocytogenes were not significant as compared with the controls. The levels of the three pathogens were reduced most profoundly when treated for 10 min with 200 ppm of $C1O_2$, and the reduction levels of S. Typhimurium, E. coli O157:H7, and L. monocytogenes were 1.17, 1.63, and 0.96 log CFU/g, respectively. When chemically injured cells were investigated using SPRAB for E. coli O157 :H7 and by selective overlay methods for S. Typhimurium and L. monocytogenes, respectively, it was noted that commercial chlorine sanitizer generated more numbers of injured pathogens than did $C1O_2$. These data indicate that $C1O_2$ treatment may prove useful in reducing the numbers of pathogenic bacteria in radish sprouts.

• Food Science of Animal Resources
• /
• v.32 no.2
• /
• pp.241-246
• /
• 2012

This report outlines the development of a rapid, simple, and sensitive detection system for pathogenic bacteria using a capillary electrophoresis-based, single strand conformation polymorphism (CE-SSCP) combined with PCR. We demonstrate that this method, used with primers targeting the V4 region of the16S rRNA gene, is capable of the simultaneous detection of 10 microbes that could be associated with foodborne illness, caused by animal-derived foods: Salmonella enterica, Listeria monocytogenes, Escherichia coli O157:H7, Campylobacter jejuni, Staphylococcus aureus, Bacillus cereus, Clostridium perfringens, Yersinia enterocolitica, Vibrio parahaemolyticus, and Enterobacter sakazakii. The traditional detection techniques are time-consuming and labor-intensive, due to the necessary task of separate cultivation of each target species. As such, the CE-SSCP-PCR method, that we have developed, has the potential to diagnose pathogens rapidly, unlike the traditional technique, in order to prevent foodborne illness in a much more efficient manner.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.4
• /
• pp.551-560
• /
• 2018

Bellflower root (Platycodon grandiflorum), which belongs to the Campanulaceae family, is a perennial grass that grows naturally in Korea, northeastern China, and Japan. Bellflower is widely consumed as both food and medicine owing to its high nutritional value and potential therapeutic effects. Since foodborne disease outbreaks often come from vegetables, understanding the public health risk of microorganisms on fresh vegetables is pivotal to predict and prevent foodborne disease outbreaks. We investigated the microbial communities on the bellflower root (n = 10). 16S rRNA gene amplicon sequencing targeting the V6-V9 regions of 16S rRNA genes was conducted via the 454-Titanium platform. The sequence quality was checked and phylogenetic assessments were performed using the RDP classifier implemented in QIIME with a bootstrap cutoff of 80%. Principal coordinate analysis was performed using the weighted Fast UniFrac distance. The average number of sequence reads generated per sample was 67,192 sequences. At the phylum level, bacterial communities from the bellflower root were composed primarily of Proteobacteria, Firmicutes, and Actinobacteria in March and September samples. Genera Serratia, Pseudomonas, and Pantoea comprised more than 54% of the total bellflower root bacteria. Principal coordinate analysis plots demonstrated that the microbial community of bellflower root in March samples was different from those in September samples. Potential pathogenic genera, such as Pantoea, were detected in bellflower root samples. Even though further studies will be required to determine if these species are associated with foodborne illness, our results indicate that the 16S rRNA gene-based sequencing approach can be used to detect pathogenic bacteria on fresh vegetables.

• Journal of Microbiology and Biotechnology
• /
• v.16 no.8
• /
• pp.1301-1305
• /
• 2006

The development of rapid, infallible, and sensitive methods of detecting foodborne pathogens has received much impetus in recent years owing to an increased public awareness of the health hazards. For the rapid and simultaneous detection of these foodborne pathogens, a multiplex PCR method was developed. Yersinia enterocolitica, Staphylococcus aureus, and Shigella spp. are bacteria of concern because of their specific growing condition that enables them to live at low temperatures. In order to detect each pathogenic bacterium, specific primers from Y. enterocolitica, St. aureus, and Sh. flexneri were selected and validated successfully. To apply this method to food stored at low temperature, Y. enterocolitica, St. aureus, and Sh. flexneri were artificially inoculated in lettuce and incubated for enrichment. The multiplex PCR assays were able to simultaneously detect three pathogens, and the presence of three bands was observed at initial inoculation levels of approximately 1$\times$10$^1$ CFU/g in lettuce. Therefore, this method could be used for simultaneous detection of Y. enterocolitica, St. aureus, and Shigella spp. contaminated in lettuce during cultivation, transportation, preservation, and storage.

• Journal of Dairy Science and Biotechnology
• /
• v.29 no.2
• /
• pp.59-68
• /
• 2011

In Korea, there are a couple of risk assessment organizations: The Animal Plant and Fisheries Quarantine and Inspection Agency(QIA) and the Korea Food and Drug Administration (KFDA). The major food laws include the Food Sanitation Act (FSA), the Livestock Product Processing Act (LPPA), and the Agricultural Products Quality Control Act (APQCA). Milk and dairy products are mostly controlled by the Food Sanitation Act and the Livestock Product Processing Act. This study was carried out to estimate the current standard methods of foodborne pathogens for dairy products, comparing the Livestock Products Processing Act with the Food Sanitation Act. The standard methods of foodborne pathogens for dairy products are composed by growth culture, isolation culture, and identification, however, standard methods of QIA and KFDA are different at the using of medium and inspection stage. Therefore, consolidation of risk management and risk assessment methods are regarded important to provide safe dairy products to consumer.

• Food Science of Animal Resources
• /
• v.38 no.4
• /
• pp.727-736
• /
• 2018

In this study, an immuno-magnetic bead (IMB)-based assay was developed to simultaneously detect Escherichia coli, Staphylococcus aureus, and Salmonella spp. and was tested in four animal-derived foods: beef, ham, egg, and ricotta cheese. The IMB-based assay exhibited good specificity by binding to five E. coli serotypes [capture efficiency (CE) average (avg.) 90.4%], five S. aureus strains (CE avg. 91.4%), and five Salmonella serotypes (CE avg. 95.4%) but not binding to non-target bacteria (CE<10%). Furthermore, the assay detected all three pathogens with a detection limit of 10 CFU/g without the need for enrichment or additional platforms. Since the results demonstrated that the IMB-based assay can effectively separate and enrich target bacteria from a variety of animal-derived food matrixes, the assay exhibits good specificity for potential use in providing rapid, immunological, presumptive identification of pathogenic bacteria.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.8
• /
• pp.1318-1331
• /
• 2018

Lettuce (Lactuca sativa L.) is a major ingredient used in many food recipes in South Korea. Lettuce samples were collected during their maximum production period between April and July in order to investigate the microbiota of lettuce during different seasons. 16S rRNA gene-based sequencing was conducted using Illumina MiSeq, and real-time PCR was performed for quantification. The number of total bacterial was greater in lettuce collected in July than in that collected in April, albeit with reduced diversity. The bacterial compositions varied according to the site and season of sample collection. Potential pathogenic species such as Bacillus spp., Enterococcus casseliflavus, Klebsiella pneumoniae, and Pseudomonas aeruginosa showed season-specific differences. Results of the network co-occurrence analysis with core genera correlations showed characteristics of bacterial species in lettuce, and provided clues regarding the role of different microbes, including potential pathogens, in this microbiota. Although further studies are needed to determine the specific effects of regional and seasonal characteristics on the lettuce microbiota, our results imply that the 16S rRNA gene-based sequencing approach can be used to detect pathogenic bacteria in lettuce.