• Journal of Food Hygiene and Safety
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• v.14 no.1
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• pp.97-103
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• 1999

This study was carried out to isolate and identify Salmonella species from poultry slaughterhouses and pork meat processing plants during the period from January 1997 to August 1998, and analyze resistance of antimicrobial agents and plasmid profiles of isolated Salmonella strains. A total of 15 Salmonella strains was isolated from poultry carcasses, swine carcasses, pork meats and cutting boards. Identified Salmonella strains were S. typhimurium, S. heidelberg, S. hilingdon, S. mbandaka, and S. virginia. Ten (66.7%) of 15 Salmonella strains showed resistance to antimicrobial agents and five strains (33.3%) of them were resistant to two or more antimirobial agents. Plasmids were isolated from three Salmonella isolates which had two or more plasmids.

• Journal of agriculture & life science
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• v.44 no.6
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• pp.111-119
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• 2010

Salmonella spp. are one of major pathogens for zoonosis in worldwide, and can replicate within host cells and generally cause enterocolitis and foodborne poisoning which represents a considerable public health burden. The present study was designated to investigate the safty for host cells, antibacterial effects of Saururus chinensis Baill water extract (SCWE) on pure culture and infection with Salmonella enterica serovar Typhimurium (S. typhimurium) in murine derived macrophage RAW 264.7 cells. The different treatment of SCWE concentration (1, 10 or $100{\mu}g/ml$) did not show any cytotoxic effect to RAW 264.7 cells for 24 h incubation. In determination of antibacterial activity of SCWE against S. typhimurium, bacterial viability was markedly decreased compared to SCWE-untreated control. In RAW 264.7 cells, SCWE significantly induced morphological change (p<0.05). In infection assay of S. typhimurium in RAW 264.7 cells pretreated with $100{\mu}g/ml$ of SCWE, which are non-cytotoxic concentration, bacterial uptake ability of macrophage was increased corresponding with morphological change, whereas bacterial survival rates within macrophage was markedly reduced comparing to that of SCWE-untreated control. Furthermore, nitric oxide (NO) production in SCWE-treated cells was slightly decreased until 24 h post infection. Taken together, these findings demonstrated that SCWE have the antibacterial activity for S. typhimurium and the protective effects against S. typhimurium infection through activating murine macrophage independent on NO, suggesting that SCWE were beneficial on the disease caused by intracellularly replicating pathogens as a safe alternatives of conventional chemotherapies.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.336.1-336
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• 1998

No Abstract, See Full Text

• Proceedings of the Microbiological Society of Korea Conference
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• 2003.05a
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• pp.10-12
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• 2003

• Proceedings of the Zoological Society Korea Conference
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• 1994.10a
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• pp.256-256
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• 1994

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 1994.10a
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• pp.255.1-255
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• 1994

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.286.2-286
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• 1997

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.287.1-287
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• 1997

No Abstract, See Full Text

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.763-770
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• 1998

Salmonella typhimurium is a causitive agent of diarrhea, fever, gastroenteritis, septicemia and sudden death in piglet. The currently used methods such as IFA, ELISA, DNA hybridization assay is needed a long-time and difficult to detect the organism in carrier animal or contaminated sample with other agents. However, it is important to detect rapidly and sensitively S typhimurium in piglet with other infectious pathogens to minimize an economic loss. Two sets of PCR primer, rfbJ forward primer(5'-AGAATATGTAATTGTCAG-3') and reverse primer(5'-TAACCGTTTCAGTAGTTC-3') were designed to amplify a 882 by fragment of Salmonella serovar type B gene. The target genomic DNA for PCR was extracted from the cultivated materials with various enrichment periods in a nonselective enrichment agar and broth with clinical specimens. The PCR is carried out here made it possible to detect the gene from two hours. Also, the amplified fragment with PCR was cloned into pGEM-T vector and digested with restrict enzyme, and sequenced for the identification of Salmonella serotype B rfbJ gene. Duplicated cultivation agar-broth followed by PCR were performed to develop a rapid and sensitive detection of S typhlmurium based on serovar type. This duplicated cultivation-PCR method provides a sensitive and rapid diagnostic tool to detect Salmonella from infected piglet with improved sensitivity.

• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1024-1032
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• 2008

Efficient expression of the Salmonella Typhimurium tdc ABCDEG operon involved in the degradation of L-serine and L-threonine requires TdcA, the transcriptional activator of the tdc operon. We found that the tdcA gene was transiently activated when the bacterial growth condition was changed from aerobic to anaerobic, but this was not observed if Salmonella was grown anaerobically from the beginning of the culture. Expression kinetics of six tdc genes after anaerobic shock demonstrated by a real-time PCR assay showed that the tdc CDEG genes were not induced in the tdcA mutant but tdcB maintained its inducibility by anaerobic shock even in the absence of tdcA, suggesting that an additional unknown transcriptional regulation may be working for the tdcB expression. We also investigated the effects of nucleoid-associated proteins by primer extension analysis and found that H-NS repressed tdcA under anaerobic shock conditions, and fis mutation delayed the peak expression time of the tdc operon. DNA microarray analysis of genes regulated by TdcA revealed that the genes involved in N-acetylmannosamine, maltose, and propanediol utilization were significantly induced in a tdcA mutant. These findings suggest that Tdc enzymes may playa pivotal role in energy metabolism under a sudden change of oxygen tension.