Microsoft Word 代晓航-二校 3516

Transcription

1 7 9 Vol. 7 No Journal of Food Safety and Quality Sep., 2016 A B C 1, 代晓航 2 1,, 郭灵安 2*, 魏超 (1., ; 2. ( ), ) 1, 2 摘要 : 目的 3 SEA SEB SEC 方法, 10 4 CFU/g ( ) 10 2 CFU/g ( ),, 8 25, GB 4789 (A-C) 结果,,, SEA SEB SEC, 25, 10 4 CFU/g SEA, 10 5 CFU/g SEC, 10 7 CFU/g SEB; 8, 48 h 结论, 3, 关键词 : ; ; Study of staphylococcal enterotoxins A, B, and C expression on strawberry DAI Xiao-Hang 1, 2, GUO Ling-An 1, 2*, WEI Chao 1, 2 (1. Analysis and Testing Center of Sichuan Academy of Agricultural Sciences, Chengdu , China; 2. Security Risk Assessment Laboratory of Ministry of Agriculture (Chengdu), Chengdu , China) ABSTRACT: Objective To investigate the correlation between the growth of Staphylococcus aureus (SA) and expression of staphylococcal enterotoxins (SE) including SEA, SEB and SEC on strawberry. Methods The enterotoxin strains were confirmed, 10 4 CFU/g and 10 2 CFU/g of bacteria were prepared and artificial pollution to the strawberry by immersion method. According to GB 4789, SA and staphylococcal enterotoxins (A-C) of strawberry were counted and detected in the storage process of 8 and 25. Results Under the suitable conditions, regardless of initial contamination level of SA in strawberry could normal growth and produce enterotoxin, especially the production of SEA was higher than that of SEB and SEC quickly. Among them, SEA could be detected from the sample when SA accumulated to more than 10 4 CFU/g at 25 storage conditions, accumulated to more than 10 5 CFU/g would be able to detect SEC, accumulated to more than 10 7 CFU/g would be able to detect SEB. SE were not detected at 8 within 48 h. Conclusion The correlation between the growth of SA and expression of SE on strawberry were studied, which would be valuable to the microbiological risk assessment and standards setting of strawberry. 基金项目 : (GJFP ) Fund: Supported by National Major Projects for Risk Assessment of Agricultural Products Quality and Safety (GJFP ) * 通讯作者 :,, gla028@163.com *Corresponding author: GUO Li-An, Associate Researcher, Analysis and Testing Center of Sichuan Academy of Agricultural Sciences, Chengdu , China. gla028@163.com

2 9, : A B C 3517 KEY WORDS: strawberry; Staphylococcus aureus; staphylococcal enterotoxins 1 引言,,,,,,,,,,, [1,2],,, 33%,, 1957~ , 6.93%( 6 ) [3] 23, SEA-SEF SEG-SET SELU-SELX TSST-1 [3-7] SEA [8],, 10 5 CFU/g, 1 μg,,,,,, 2 材料与方法 2.1 材料 : 142 : NaCl (, ) 0.1% A-C, 7.5%NaCl, BP,, : DHP-9082 ( ) Mini-bk ( ) DW-Hl100 ( ) 2.2 方法 金黄色葡萄球菌收集 142, [9] 菌液制备及染菌 0.5, 0.1%, 10 4 CFU/g( ) 10 2 CFU/g( ),,, 7.5%NaCl (36 ),, 贮存及检测 2~4, 0~25,, 2, 8 25, 8, 25,, 8 12 h, 25 5 h, 2, 3 结果与分析 3.1 金黄色葡萄球菌收集结果 142 3, 2% 菌落计数结果, 10 4 CFU/g 10 2 CFU/g, 3, 3, SEA SEB SEC 1 C T, 10 ng/ml, A B C, SEA SEC, SEA SEB SEC, [10] 不同贮存条件下高低初始污染量对金黄色葡萄球菌产毒素的影响 贮存条件下产毒素情况 25, 1 2

3 Fig. 1 1 The results of staphylococcal enterotoxins detection 表 1 25 贮存条件下草莓中金黄色葡萄球菌产毒素结果 Table 1 The results of staphylococcal enterotoxins expression at 25 storage (h) G/D G/D G/D G/D G/D G/D G/D /+ SEA /+ /+ SEB /+ - + SEC /+ /+ G: ; D: : +: ; -: ; : G: Sample with high pollution; D: Sample with low pollution; +: Positive; -: Negative; : Not analyzed 2 25 Fig. 2 Growth of Staphylococcus aureus at 25 storage in the strawberry 2, D D, G G, 25, 5 h 1 2, 3 SEA SEC SEB, SEA 5h 25 h,, CFU/g SEC 10 h 25 h,, CFU/g, SEB 25 h 35 h,, CFU/g, 3,, SEA,,,, SEA SEB SEC

4 9, : A B C 3519 表 2 8 贮存条件下草莓中金黄色葡萄球菌产毒素情况 Table 2 The results of staphylococcal enterotoxins expression at 8 storage (h) G/ D G/ D G/ D G/ D SEA -/ SEB SEC G: ; D: : +: ; -: ; : G: Sample with high pollution; D: Sample with low pollution; +: Positive; -: Negative; : Not analyzed [11],, SEA 贮存条件下产毒素情况 h SEA SEC SEB 4 结论,,,,,,, 6l gcfu/g, l gcfu/g [12-15], ph,,, SEA, CFU/g,, SEB SEC 参考文献 3 8 Fig. 3 Growth of Staphylococcus aureus at 8 storage in the strawberry 3, D D, G G,,, [1],,,. VITEK [J]., 2007, 28(3): Pan J, Huang XD, Xie HM, et al. Experiment of hygienical microbiology examination and bacteria identification by VITEK for strawberry [J]. Food Sci, 2007, 28(3): [2],,,. [J]., 2014, 27(6): Wei C, Guo LA, Hu Li, et al. Pesticide residues detection of strawberries

5 surface and its effects on microflora [J]. Southwest China J Agric Sci, 2014, 27(6): [3] Ono HK, Omoe K, Imanishi K,et al. Identification and characterization of two novel Staphylococcal enterotoxins types S and T [J]. Infect Immun, 2008, 76(11): [4] Lina G, Bohach GA,Nair SP, et al. Standard nomenclature for the superantigens expressed by Staphylococcus [J]. J Infect Dis, 2004, 189(12): [5] Pereira V, Lopes C, Castro A, et al. Characterization for enterotoxin production, virulence factors, and antibiotic susceptibility of Staphylococcus aureus isolaties from various foods in Portugal [J]. Food Microbiol, 2009, 26(3): [6] Letertre C, Perelle S, Dilasser F. et al. A strategy based on 5 nuclease multiplex PCR to detect enterotoxin genes sea to sej of Staphylococcus aureus [J]. Mol Cell Probe, 2003, 17(5): [7],,. 1 [M]..., 2015: Liu ZS, Ren HL, Shun HB. Food Pathogenic Microbiology 1Edition [M]. Beijing: Science Press, 2015: [8],,. [J]., 2015, 38(6): Chen WY, You CP, Liu ZM. Progress in research on Staphylococcus aureus exotoxins [J]. Sci Technol Dairy, 2015, 38(6): [9] GB [S]. GB National food safety standard food microbiological examination: Staphylococcus aureus [S]. [10],,,. [J]., 2012, 45(19): Yang J,Yang J, Huang JC, et al. Distribution and temporal expression of Staphylococcus aureus enterotoxin genes in foodborne Staphylococcus aureus strains [J]. Sci Agric Sin, 2012, 45(19): [11] Tseng CW, Zhang S, Stewart GC. Accessory gene regulator control of Staphyloccoccal enterotoxin D gene expression [J]. J Bacteriol, 2004, 186(6): [12],,,.. [J]., 2006, 16(8): Chao GX, Jiao XA, Zhou LP, et al. Enterotoxin production and resistance to anti-microbial drugs of Staphylococcus aureus in selected retail food products [J]. Chin J Health Lab Technol, 2006, 16(8): [13]., [D]. :, Wang T. The study on the growth, enterotoxin producing and there inhibitor methods of Staphylococcus aureus in whipping cream [D]. Shanghai: Shanghai Ocean University, [14],,. [J].., 2009, 10: Zhang HW, Zheng DM, Kong BH. Study on the growth and toxinproducing of Staphylococcus aureus in raw milk stored in low temperature [J]. Acad Period Farm Prod Process, 2009, 10: [15],,,. [J]., 2012, 39(12): Jia HL, Yi WZ, Luo HX,, et al. Research on Staphylococcus aureus and Staphylococcal enterotoxin in the processing of fermented beef [J]. Chin Anim Husb Vet, 2012, 39(12): 作者简介 ( 责任编辑 : 白洪健 ) 代晓航, 硕士, 副研究员, 主要研究方向为农产品微生物风险评估 @qq.com 郭灵安, 学士, 副研究员, 主要研究方向为农产品风险评估工作 gla028@163.com