RpoE缺陷对甲型副伤寒沙门氏菌在肉制品加工中热失活特性的影响
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摘要
目的:RpoE作为由rpoE基因编码的σ因子,是普遍存在于革兰氏阴性细菌中的一类调节基因,对细菌响应各种环境胁迫起着重要的调节作用。为了解甲型副伤寒沙门氏菌rpoE基因在肉制品加工过程中的热应激响应特征。方法:本研究首先对缺陷株△rpoE在最适温度的生长情况进行分析,然后以55,63,72℃对接种10~8CFU/g甲型副伤寒沙门氏菌缺陷株△rpoE和野生株的介质进行热处理,测定处理后样品中甲型副伤寒沙门氏菌的残存数量,比较缺陷株和野生株在肉制品加工中的失活情况。结果:研究结果表明,在最适温度37℃条件下,缺陷株和野生株的生长能力没有显著性差异。野生株和缺陷株在55℃的D值分别为14.0980,10.8933 min,在63℃的D值分别为1.3078,0.3147 min,在72℃的D值分别为0.9885,0.9135 min,并且3个温度下甲型副伤寒沙门氏菌缺陷株和野生株的D值之间有显著性差异(t<0.05),因此野生株的耐热能力显著高于缺陷株。结论:rpoE基因对甲型副伤寒沙门氏菌的耐热性起了重要作用,本文为进一步探讨甲型副伤寒沙门氏菌耐热机理及其控制提供了理论参考。
Objective: σ factor, a regulatory gene, is common in gram negative bacteria, and it plays an important role in regulating the response of bacteria to various environmental stresses. In order to understand the thermal inactivation characterization of rpoE on Salmonella paratyphi A in the meat products processing. Methods: In this study, the first, the growth of rpoE gene mutant strains and wild strains at the optimum temperature were investigated, and then the vaccinated 10~8 CFU/g Salmonella paratyphi A mutant strains and wild strains in different medium, then subjected to thermal treatment. The surviving cell number was counted on selective media, next the inactivation of mutant strains and wild strains were compared in meat products processing. Results: The results showed that the growth ability was no significant different between mutant and wild strains, The D values of the wild and the mutant strains were 14.0980 min and 10.8933 min at 55 ℃, at 63 ℃ were 1.3078 min and 0.3147 min, at 72 ℃ were 0.9885 min and 0.9135 min. and there was a significant difference(t <0.05) in the D value of between Salmonella paratyphi A mutant strains and wild strains, so the heat resistance of mutant strains were significantly weaker than the wild strain. Conclusion: The rpoE gene plays an important role in the thermotolerance of Salmonella paratyphi A, which provides a theoretical reference for the further study on the heat resistant mechanism and the control of Salmonella paratyphi A.
Objective: σ factor, a regulatory gene, is common in gram negative bacteria, and it plays an important role in regulating the response of bacteria to various environmental stresses. In order to understand the thermal inactivation characterization of rpoE on Salmonella paratyphi A in the meat products processing. Methods: In this study, the first, the growth of rpoE gene mutant strains and wild strains at the optimum temperature were investigated, and then the vaccinated 10~8 CFU/g Salmonella paratyphi A mutant strains and wild strains in different medium, then subjected to thermal treatment. The surviving cell number was counted on selective media, next the inactivation of mutant strains and wild strains were compared in meat products processing. Results: The results showed that the growth ability was no significant different between mutant and wild strains, The D values of the wild and the mutant strains were 14.0980 min and 10.8933 min at 55 ℃, at 63 ℃ were 1.3078 min and 0.3147 min, at 72 ℃ were 0.9885 min and 0.9135 min. and there was a significant difference(t <0.05) in the D value of between Salmonella paratyphi A mutant strains and wild strains, so the heat resistance of mutant strains were significantly weaker than the wild strain. Conclusion: The rpoE gene plays an important role in the thermotolerance of Salmonella paratyphi A, which provides a theoretical reference for the further study on the heat resistant mechanism and the control of Salmonella paratyphi A.
引文
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[7]BAUDIN A, OZIER-KALOGEROPOULOS O, DENOUEL A, et al. A simple and efficient method for direct gene deletion in Saccharomyces cerevisiae[J].Nucleic Acids Research, 1993, 21(14):3329-3330.
[8]DATSENKO K A, WANNER B L. One-step inactivation of chromosomal genes in Escherichia coli K-12 using PCR products[J]. Proceedings of the National Academy of Sciences of the United States of America, 2000, 97(12):6640-6645.
[9]SOLANO C, GARCíA B, VALLE J, et al. Genetic analysis of Salmonella enteritidis, biofilm formation:critical role of cellulose[J]. Molecular Microbiology,2002, 43(3):793-808.
[10]MUYRERS J P, ZHANG Y, TESTA G, et al.Rapid modification of bacterial artificial chromosomes by ET-recombination[J]. Nucleic Acids Research,1999, 27(6):1555-1557.
[11]YU D, ELLIS H M, LEE E C, et al. An efficient recombination system for chromosome engineering in Escherichia col i[J]. Proceedings of the National Academy of Sciences, 2000, 97(11):5978-5983.
[12]白光兴,孙志伟,黄莺,等.利用Red重组系统对大肠杆菌ClpP基因的敲除[J].中国生物化学与分子生物学报, 2005, 21(1):35-38.
[13]PE?AS A D L, CONNOLLY L, GROSS C A. SigmaE is an essential sigma factor in Escherichia coli[J]. Journal of Bacteriology, 1997, 179(21):6862-6864.
[14]ROLHION N, CARVALHO F A, DARFEUILLEMICHAUD A. OmpC and theσE, regulatory pathway are involved in adhesion and invasion of the Crohn’s disease-associated Escherichia coli, strain LF82[J]. Molecular Microbiology, 2007, 63(6):1684-1700.
[2]HEIR E, HOLCK A L, OMER M K, et al. Effects of post-processing treatments on sensory quality and Shiga toxigenic Escherichia coli, reductions in dryfermented sausages[J]. Meat Science, 2013, 94(1):47-54.
[3]DUCIC M, KLISARA N, MARKOV S, et al. The fate and pasteurization-based inactivation of Escherichia coli, O157, Salmonella, Typhimurium and Listeria monocytogenes, in dry, fermented sausages[J]. Food Control, 2016, 59:400-406.
[4]ZHANG S. Dental caries and vaccination strategy against the major cariogenic pathogen, Streptococcus mutans[J]. Current Pharmaceutical Biotechnology, 2013,14(11):960-966.
[5]BUSBY S, EBRIGHT R H. Promoter structure,promoter recognition, and transcription activation in prokaryotes[J]. Cell, 1994, 79(5):743-746.
[6]HEIN I, FLEKNA G, KRASSNIG M, et al. Realtime PCR for the detection of Salmonella spp. in food:An alternative approach to a conventional PCR system suggested by the FOOD-PCR project[J].Journal of Microbiological Methods, 2006, 66(3):538-547.
[7]BAUDIN A, OZIER-KALOGEROPOULOS O, DENOUEL A, et al. A simple and efficient method for direct gene deletion in Saccharomyces cerevisiae[J].Nucleic Acids Research, 1993, 21(14):3329-3330.
[8]DATSENKO K A, WANNER B L. One-step inactivation of chromosomal genes in Escherichia coli K-12 using PCR products[J]. Proceedings of the National Academy of Sciences of the United States of America, 2000, 97(12):6640-6645.
[9]SOLANO C, GARCíA B, VALLE J, et al. Genetic analysis of Salmonella enteritidis, biofilm formation:critical role of cellulose[J]. Molecular Microbiology,2002, 43(3):793-808.
[10]MUYRERS J P, ZHANG Y, TESTA G, et al.Rapid modification of bacterial artificial chromosomes by ET-recombination[J]. Nucleic Acids Research,1999, 27(6):1555-1557.
[11]YU D, ELLIS H M, LEE E C, et al. An efficient recombination system for chromosome engineering in Escherichia col i[J]. Proceedings of the National Academy of Sciences, 2000, 97(11):5978-5983.
[12]白光兴,孙志伟,黄莺,等.利用Red重组系统对大肠杆菌ClpP基因的敲除[J].中国生物化学与分子生物学报, 2005, 21(1):35-38.
[13]PE?AS A D L, CONNOLLY L, GROSS C A. SigmaE is an essential sigma factor in Escherichia coli[J]. Journal of Bacteriology, 1997, 179(21):6862-6864.
[14]ROLHION N, CARVALHO F A, DARFEUILLEMICHAUD A. OmpC and theσE, regulatory pathway are involved in adhesion and invasion of the Crohn’s disease-associated Escherichia coli, strain LF82[J]. Molecular Microbiology, 2007, 63(6):1684-1700.