• Food Science of Animal Resources
• /
• v.31 no.4
• /
• pp.557-562
• /
• 2011

The study was performed to investigate microbial and physicochemical properties of domestic liquid eggs during cold storage. The liquid eggs used in the experiment were whole liquid, liquid egg yolks, and liquid egg whites. All samples were analyzed in summer and winter. The aerobic microorganisms were 1,270-83,300 CFU/g from non-sterilized liquid eggs produced in summer and their numbers increased from those produced in winter (ND, ~4,330 CFU/g). Total coliforms were not observed in non-sterilized whole liquid and non-sterilized liquid egg yolk regardless of season. Total coliforms from nonsterilized products were not detected in liquid egg whites during cold storage. Salmonella sp. was not observed in any of the liquid egg products. However, Pseudomonas sp., Pseudomonas geezennei, Pseudomonas otitidis, and Pseudomonas aeruginosa were identified by 16S rRNA from non-sterilized whole liquid eggs produced in summer. The pH and viscosity of whole liquid eggs and liquid egg whites were not different between the sterilized and non-sterilized treatments during cold storage. These results suggest that managing cross-contamination is necessary when non-sterilized liquid eggs are processed in summer.

• Journal of Microbiology
• /
• v.42 no.3
• /
• pp.216-222
• /
• 2004

In a previous paper, the ogdH gene that encodes 2-oxoglutarat dehydrogenase was isolated from Salmonella typhimurium. The catalytic N-terminal region in the enzyme was found to be very specific for the Salmonella species. Therefore, the aim of the present study was to detect S. typhimurium in food sources using primers designed for OGDH-l and OGDH-2 which were based on the salmonella-specific region of the ogdH gene. A simple polymerase chain reaction (PCR) detection method was developed to detect low numbers of S. typhimurium in a chicken meat microbial consortium. Using the ogdH-specific primers under stringent amplification conditions and for gene probe analysis, fewer than 100 colony-forming units (CFUs) were detectable when pure cultures were employed. When the PCR assay was run on S. typhimurium-contaminated meat contents, only the positive meat samples containing as few as 200 CFUs reacted to the assay. The method employed for sample processing is simple and it was determined to provide a sensitive means of detecting trace amounts of S. typhimurium-specific sequences in the presence of mixed meat microbial populations. When compared with six representative intestinal gram-negative bacterial strains in foods, including Vibrio parahaemolyticus, V. vulnificus, Enterobacter cloacae, E. coli O157:H7, Pseudomonas aeruginosa, and Proteus sp., S. typhimurium had a unique and distinct PCR product (796 bp). In conclusion, the two OGDH primers were found to be rapid and sensitive detectors of Salmonella spp for the PCR method.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.12
• /
• pp.1605-1614
• /
• 2022

The strains associated with foodborne Salmonella enterica Thompson outbreaks in Korea have not been identified. Therefore, we characterized S. Thompson strains isolated from chocolate cakes linked to foodborne outbreaks in Korea. A total of 56 strains were isolated from preserved cake products, products in the supply chain distribution, the manufacturer's apparatus, and egg white liquid products used for cream preparation. Subsequently, serological typing, pathogenic gene-targeted polymerase chain reaction (PCR), pulsed-field gel electrophoresis (PFGE), and whole-genome multi-locus sequence typing (wgMLST) were performed to characterize these isolates. The antigen formula of all isolates was 7:k:1,5, namely Salmonella enterica subsp. enterica Serovar Thompson. All 56 isolates harbored invA, his, hin, and stn, and were negative for sefA and spvC based on gene-targeted PCR analyses. Based on PFGE results, these isolates were classified into one group based on the same SP6X01.011 pattern with 100% similarity. We selected 19 strains based on the region and sample type, which were subjected to wgMLST. Although the examined strains showed 100% similarity, they were classified into seven clusters based on allelic differences. According to our findings, the cause of these outbreaks was chocolate cake manufactured with egg white liquid contaminated with the same Salmonella Thompson. Additionally, comparative analysis of wgMLST on domestic isolates of S. Thompson from the three outbreaks showed genetic similarities of over 99.6%. Based on the results, the PFGE and wgMLST combination can provide highly resolved phylogeny and reliable evidence during Salmonella outbreak investigations.

• Journal of the Korean Ceramic Society
• /
• v.34 no.1
• /
• pp.13-22
• /
• 1997

Water-soluble phosphate glasses containing Ag and Cu ion were prepared through melting process. Dis-solution characteristics, bactericidal effect and cytotoxicity were investigated with composition and time in D. I. water using the powdered sample. Surface change were observed with increasing dissolution time us-ing the bulk specimen. Dissolution amount was maximum at the molar Ag:Cu ratio of 1 and increased with increasing time. The behavior of dissolution was total dissolution from the early stage. But no new layer was observed at the glass surface during dissolution. The bactericidal effect for pseudomonas sp, e. coli, sta-phylococcus aureus, and salmonella increased with increasing dissolution amount and therefore great bac-tericidal effect appeared. The result of cytotoxicity experiment to L929 showed that solution with more than 10 ppm of Ag ion had strong cytotoxicity.

• Korean journal of food and cookery science
• /
• v.21 no.1 s.85
• /
• pp.53-63
• /
• 2005

This study was carried out to determine the inhibitory effect of methanol extract from kimchi ingredients against Salmonella typhimurium, Listeria monocytogenes, Staphylococcus aureus, and Esherichia coli which are pathogenic microorganisms and Aspergillus sp. Penicillium sp. Antimicrobial activity of methanol extracts was tested against bacteria by paper disc method. Antifungal activity of methanol extracts was shown by hyphal growth inhibition ratio. The methanol extracts from all materials were effective against E. coli among them. And the antimicrobial activity of the methanol extracts from ginger and onion were lower than the others. The antifungal activity of the methanol extracts from radish, ginger, and garlic were effective against Aspergillus sp. and Penicillium sp. In the result of identifying antimicrobial effect rate, the methanol extracts from red pepper and radish had more than $40\%$ against S. typhimurium and more than $30\%$ against E. coli. Also the methanol extracts from onion had an high inhibitory effect rate of more than $50\%$ against S. typhimurium and that from garlic had more than $60\%$ against S. aureus. The minimum inhibitory concentration(MIC) of red pepper was examined 500 $\mu$g/mL against L. monocytogenes. This value was the lowest among the others.

• Journal of Microbiology
• /
• v.39 no.4
• /
• pp.334-337
• /
• 2001

The degradative pathway of homoprotocatechuate (HPC) is the bacterial routhe wherby 3,4-dihydrox-yphenylactic acid is catabolized to pyruvate and succinate by a series of sequential reactions . The HPC is catalzed by homoprotocatechuate 2, 3-dioxygenase(HPC-2,3O) to from 5-carboxymethy1-2-hydroxy-muco semialdehyde. In this study, the hha D gene encoding. HPC, 2, 3O was Cloned from the chromo-somal DNA of Pseudomonas sp. DJ-12 and its nucleotide sequence was analyzed. The open reding frame of hpaD gene was found to be composed of 864 nucleotide pairs and to encode a poypetide with 287 amino acide residues. The deduced amino acid sequence of the HPC-2,3O from Pseudomonas. sp. DJ-12 exhibited 60~64% homology with those of the corresponding enzymes from E. coli. Salmonella enterica, and Klebsiella pneumoniae.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2003.10a
• /
• pp.201.1-201
• /
• 2003

생균제로서 가능성 있는 유산균의 선별을 위해 발효식품인 동치미로부터 분리된 균주들의 내산성, 내담즙성, 내췌장액성 및 유해균 억제능을 조사하였다. 특히 분리된 균종 중에서 FF-3가 인공위액과 담즙산에 대한 높은 내성을 나타내었을 뿐만 아니라, Salmonella sp. 과 Escherichia coli에 대하여 높은 항균 활성을 나타내었다. FF-3유래 박테리오신은 그람양성 및 음성 세균에서 넓은 항균 범위를 나타내었다. 본 연구에서 최종선별된 FF-3 균주를 16s rDNA sequence 동정한 결과 Lactobacillus sp.으로 확인되어 FF-3으로 명명하였다.

• Microbiology and Biotechnology Letters
• /
• v.47 no.3
• /
• pp.459-464
• /
• 2019

This study aimed to identify and characterize the antimicrobial activity of prodigiosin produced by Serratia sp. $PDGS^{120915}$ isolated from stream water in Busan, Korea; the identification was performed using phonological, biochemical, and molecular techniques, including 16S rRNA sequence analysis. Prodigiosin from the bacterial culture was purified by high-performance liquid chromatography (HPLC), and its antimicrobial activity and minimum inhibitory concentrations (MICs) were evaluated against 10 intestinal pathogenic gram-positive and negative bacteria. The results revealed that the isolated prodigiosin exhibited high antimicrobial activity against Listeria monocytogenes, Bacillus cereus, Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus, and Vibrio parahaemolyticus; further, the isolated prodigiosin showed minimum inhibitory concentrations (MICs) between $3{\mu}g/ml$ and 30 mg/ml, but they were not active against Bacillus subtilis, Enterococcus faecalis, Klebsiella pneumonia, and Escherichia coli. In conclusion, prodigiosin isolated from Serratia sp. $PDGS^{120915}$ showed high antimicrobial activity against intestinal pathogenic bacteria and has potential applications in the development of new antimicrobial agents.

• KSBB Journal
• /
• v.26 no.1
• /
• pp.62-68
• /
• 2011

To isolate Lactic acid bacteria for animals, we have screened from Kim-chi, swine intestine, swine feces, and dairy products by random selection and anti-viral, antipathogenic bacteria test. Among them, CLP-1 shown that inhibitory effect against rotavirus, porcine epidemic diarrhea (PED) virus, Salmonella sp, and E.coli. By examining biological property, API-ZYM and identified Lactobacillus plantarum by 16S rDNAgene sequence. CLP-1 determined resistance to low pH and bile salt. Futhermore, the cell body of CLP-1 adhered to the intestinal epithelium tissue of swine and Caco-2 cell. CLP-1 was examined on cell immune system modulating activity in vitro. The whole cell and cell culture supernatant was increasing of interferon-${\beta}$ activity. And then, CLP-1 increased prevention effect by Salmonella enteritidis infection in SPF chickens. And we determined similar result in pigs.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.24 no.3
• /
• pp.440-445
• /
• 1995

The antimutagenic effects of juices from green pepper(GP), red pepper leaf(RPL), red pepper(RP) and sweet pepper(SP) were examined by the Ames method using Salmonella typhimurium TA100. The juice supernatants of GP, RPL and RP showed antimutagenic activities against afltoxin B1(AFB1) in Salmonella typhimurium TA 100. The juice supermatants of GP and RPL also exhibited the inhibitory effects(p<0.05) to the mutagenicities induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) and 4-nitro-quinoline-1-oxide(4-NQO). The juice of RP showed antimutagenic activities against indirect mutagen of AFB1, however, the activity was reduced at higher concentration(5.0%), furthermore, as the adding concentration of sample increased to 5.0%, it exhibited slight comutagenicith on direct mutagen of MNNG. Theantimutagenic activities of GP and RPL juices were reduced significantly after heating at 100℃ for 20min, supposing that the antimutagenic compound(s) in the juices were heat labile.