Isolation of Egg-Contaminating Bacteria and Evaluation of Bacterial Radiation Sensitivity

계란 오염 세균의 분리 및 분리 균주의 감마선 감수성 평가

  • Kim, Dong-Ho (Department of Radiation Biotechnology, Korea Atomic Energy Research Institute) ;
  • Yun, Hye-Jeong (Department of Radiation Biotechnology, Korea Atomic Energy Research Institute) ;
  • Song, Hyun-Pa (Department of Animal Science and Biotechnology, Chungnam National University) ;
  • Lim, Byung-Lak (H&BT Korea Co., Ltd.) ;
  • Jo, Cheo-Run (Department of Animal Science and Biotechnology, Chungnam National University)
  • 김동호 (한국원자력연구원 정읍방사선과학연구소) ;
  • 윤혜정 (한국원자력연구원 정읍방사선과학연구소) ;
  • 송현파 (충남대학교 동물자원생명과학과) ;
  • 임병락 ;
  • 조철훈 (충남대학교 동물자원생명과학과)
  • Published : 2008.10.31

Abstract

was performed and Staphylococcus sciuri, Bacillus cereus, Escherichia coli, Proteus mirabilis, and Enterococcus faecalis were identified. No Salmonella strain, a typical contaminant of eggs, was found. The radiation sensitivities of isolated bacteria and Salmonella typhimurium, in an inoculated model system, were expressed in $D_{10}$ values. The ranges of $D_{10}$ values shown by S. typhimurium, S. sciuri, B. cereus, E. coli, P. mirabilis, and E. faecalis were 0.365-0.399 kGy, 0.418-0.471 kGy, 1.075-1.119 kGy, 0.280-0.304 kGy, 1.132-1.330 kGy, and 0.993-1.290 kGy, respectively. The growth of all six test bacteria in eggs (inoculated at $10^6-10^7\;CFU/g$) during 3 days of post-irradiation storage at ambient conditions ($25^{\circ}C$) was recorded. S. typhimurium was eliminated by irradiation at 3 kGy, and E. coli and S. sciuri were eliminated by irradiation at 5 kGy. The viable cell counts of B. cereus, P. mirabilis, and E. faecalis in eggs showed 4-6 log reductions after irradiation with 5 kGy.

계란의 주요 오염 미생물을 분리하여 계란의 난각 표면과 내부에 접종한 다음 감마선 살균을 실시하여 각 미생물의 감마선 감수성을 평가하였다. 본 실험에서 시중 유통 계란으로부터 분리된 미생물을 16S rDNA 염기서열분석을 통하여 잠정 동정한 결과 Staphylococcus sciuri, Bacillus cereus, Escherichia coli, Proteus mirabilis 및 Enterococcus faecalis의 5 종의 미생물이 확인되었으며 Salmonella는 검출되지 않았다. 표준 시험균주인 S. Typhimurium을 비롯하여 계란 분리균주 5종을 계란 난각 표면과 내부에 $10^{6{\sim}7}\;CFU/g$되게 접종한 다음 감마선을 조사하여 D10 값으로 감마선 감수성을 평가한 결과, S. Typhimurium은 $0.365{\sim}0.399\;kGy$, Staphylococcus sciuri는 $0.418{\sim}0.471\;kGy$, B. cereus는 $1.075{\sim}1.119\;kGy$, E. coli는 $0.280{\sim}0.304\;kGy$, P. mirabilis는 $1.132{\sim}1.330\;kGy$, 그리고 Enterococcus faecalis는 $0.993{\sim}1.290\;kGy$ 수준의 D10 값을 나타내었다. 감마선 조사 후 $25^{\circ}C$ 상온저장 조건에서 미생물의 생장을 살펴본 결과, S. Typhimurium은 3 kGy에서, E. coli와 Staphylococcus sciuri는 5 kGy에서 완전 사멸되었으며 다른 미생물 접종 시험군에서도 각각의 $D_{10}$ 값에 준하는 미생물생장 억제효과가 나타났다. 일반적인 계란의 미생물 오염 수준을 102 CFU/g 수준임을 감안할 때, 3 kGy의 감마선 조사선량으로 계란의 미생물 제거가 가능할 것으로 사료되었다.

Keywords

References

  1. Yoo, Y.M. (2003) Changes in quality of eggs with storage temperature and time. Monthly Poultry, 3, 119-124
  2. Kim, J.W., Kim, H.C. and Hur, J.W. (1998) Quality changes of egg products during storage. Korean J. Food Sci. Technol., 30, 1480-1483
  3. Jang, K.I., Park, J.H. and Kim, K.Y. (1999) Studies on Samonella enteritidis contamination in chicken egg using confocal scanning laser microscopy. Korean J. Food Sci. Technol., 31, 771-777
  4. Jones, F.T., Rives, D.V. and Carey, J.B. (1995) Salmonella contamination in commercial eggs and an egg production facility. Poult. Sci., 74, 753-757 https://doi.org/10.3382/ps.0740753
  5. Gast, R.K. and Beard, C.W. (1992) Detection and enumeration of Salmonella enterotidis in fresh and stored egg laid by experimentally infected hens. J. Food Prot., 55, 152-156 https://doi.org/10.4315/0362-028X-55.3.152
  6. Schoeni, J.L., Glass, K.A., McMernott, J.L. and Wong, A.C.L. (1995) Growth and penetration of Salmonella enteritidis, Salmonella heidelberg and Salmonella typhimurium in egg. Int. J. Food Microbiol., 24, 385-396 https://doi.org/10.1016/0168-1605(94)00042-5
  7. Jones, F.T., Rives, D.V. and Carey, J.B. (1995) Salmonella contamination in commercial eggs and an egg production facility. Poult. Sci., 74, 753-757 https://doi.org/10.3382/ps.0740753
  8. Gast, R.K. and Beard, C.W. (1992) Detection and enumeration of Salmonella enteritidis in fresh and stored eggs laid by experimentally infected hens. J. Food Prot., 55, 152-156 https://doi.org/10.4315/0362-028X-55.3.152
  9. Hmmack, T.S., Sherrod, P.S., Bruce, V.R., June, G.A., Satchell, F.B. and Andrews, W.H. (1993) Growth of Salmonella enteritidis in grade A eggs during prolonged storage. Poult. Sci., 72, 373-377 https://doi.org/10.3382/ps.0720373
  10. Lee, S.H., No, H.K. and Jeong, Y.H. (1996) Effect of chitosan coating on quality of egg during storage (in Korea). J. Korean Soc. Food Nutr., 25, 288-293
  11. Jang, K.I., Park, J.H. and Kim, K.Y. (1999) Studies on Salmonella enteritidis contamination in chiken egg using confocal scanning laser microscopy. Korean J. Food Sci. Technol., 31, 771-777
  12. Farag, R.S., Daw, Z., Shallan, M.A. and Ebtesam, A.M. (1994) Biochemical and microbial studies on the efficiency of some coating materials for egg preservation. Int. J. Food Sci. Nutr., 45, 263-273 https://doi.org/10.3109/09637489409166167
  13. FAO/IAEA/WHO (1999) High-dose irradiation: Wholesomeness of food irradiated with doses above 10 kGy. In WHO technical report series 890. World Health Organization, Geneva. p.49-77
  14. Byun, M.W. (1997). Application and aspect of irradiation technology in food industry. Food Sci. Ind., 30, 89-100
  15. Grant, I.R. and Patterson, M.F. (1992) Sensitivity of foodborne pathogens to irradiation in the components of a chilled ready meal. Food Microbiol., 9, 95-103 https://doi.org/10.1016/0740-0020(92)80017-X
  16. Byun, M.W. and Lee, J.W. (2003) Application of irradiation technology for food safety and security. Food Sci. Ind., 36, 25-41
  17. Thayer, D.W. (1994) Wholesomeness of irradiated foods. Food Technol., 48, 58-67
  18. ISO 6579 (1993) Microbiology-General Guidance on Methods for the Detection of Salmonella Interantional Organization of Stadardization
  19. Dario, D.M., Luciana, C., Elisabetta D., Simona, D.P., Emma, F. and Laura, T. (2003) Evaluation of DNA extraction methods for use in combination with sybr green I real-time PCR to detect Salmonella enterica serotype enteritidis in poultry. Appl. Environ. Microbiol., 69, 3456-3461 https://doi.org/10.1128/AEM.69.6.3456-3461.2003
  20. Breidt, F. and Fleming, H.P. (1996) Identification of lactic acid bacteria by ribotyping. J. Rapid Methods Automation Microbiol., 4, 219-233 https://doi.org/10.1111/j.1745-4581.1996.tb00125.x
  21. Harrigan, W.F. and Mccane, M.E. (1976) Laboratory Methods in Food and Dairy Microbiology. Academic Press, London, p.25-146
  22. Moon, E.S. and Ko, M.H. (2006) Quality grade of eggs in the food stores. Safe Food, 1, 23-26
  23. Lee, S.M., Kim, K.H., Lee, J.G., Park, E.J., Lee, S.W. and Hong, C.H. (2002) Hygienic quality of eggs in the department food stores in the Incheon metropolitam area. J. Food Hyg. Safety, 17, 129-136
  24. Yook, H.S., Kim, S., Lee, K.H., Kim, Y.J., Kim, K.P. and Byun, M.W. (1998) Gamma-radiation sensitivity of pathogen bacteria in beef. Korean J. Food Sci. Technol., 30, 1432-1438
  25. Maxcy, R.B. (1983) Significance of residual organism s in foods after substerilizing doses of gamma irradiation. J. Food Safety, 5, 203-211 https://doi.org/10.1111/j.1745-4565.1983.tb00471.x
  26. Thayer, D.W., Boyd, G., Muller, W.S., Lipson, C.A., Hayne, W.C. and Baer, S.H. (1990) Radiation resistance of Salmonella. J. Ind. Microbiol., 5, 383-390 https://doi.org/10.1007/BF01578097
  27. Kim, D.H., Yook, H.S., Youn, K.C., Cha, B.S., Kim, J.O. and Byun, M.W. (2000) Changes of microbiological and general qulity characteristics of gamma irradiated Chungkukjang. Korean J. Food Sci. Technol., 32, 896-901
  28. Briggs, A. (1966) The resistance of spores of the Bacillus to phenol, heat and radiation. J. Appl. Bacteriol., 29, 490-504 https://doi.org/10.1111/j.1365-2672.1966.tb03500.x
  29. Farkas, J. and Roberts, T.A. (1976) The effect of sodium chloride, gamma irradiation and/or heating on germination and development of spores of Bacillus cereus in single germinant and complex media. Acta Alimentaria, 5, 289-302
  30. Ma, K. and Maxcy, R.B. (1981) Factors influencing radiation resistance of vegetative bacteria and spores associated with radappertization of meat. J. Appl. Bacteriol., 36, 677-682
  31. Kim, D.H., Ahn, H.J., Yook, H.S., Kim, M.J., Sohn, C.B. and Byun, M.W. (2000) Quality properties of gamma irradiated Samjang, seasoned soybean paste during storage. Korean J. Food Sci. Technol., 32, 396-401
  32. Kim, D.H., Song, H.P., Lee, Y.S., Cha, B.S., Kim, B.K. and Byun, M.W. (2004) Effects of gamma irradiation on the shelf stability of whole baked egg. Korean J. Food Preserv., 11, 394-399
  33. Jang, A., Lim, D.G., Jeon, H.J., Jo, C., Kim, I.J. and Lee, M. (2007) Optimum conditions for the seperation of lecithin from egg yolk by response surface methodology. Korean J. Food Sci. Ani. Resour., 27, 482-488 https://doi.org/10.5851/kosfa.2007.27.4.482