GB 4789.11-2014 PDF EnglishUS$70.00 · In stock · Download in 9 seconds
GB 4789.11-2014: National Food Safety Standard -- Microbiological Examination of Food Hygiene -- Examination of Streptococcus Hemolyticus Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedure Status: Valid GB 4789.11: Historical versions
Similar standardsGB 4789.11-2014: National Food Safety Standard -- Microbiological Examination of Food Hygiene -- Examination of Streptococcus Hemolyticus---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GB4789.11-2014 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA National Food Safety Standard – Food Microbiological Examination – Examination of β-type Hemolytic Streptococcus Issued on. DECEMBER 1, 2014 Implemented on. MAY 1, 2015 Issued by. National Health and Family Planning Commission of the People's Republic of China Table of ContentsForeword... 3 1 Scope... 4 2 Terms and Definitions... 4 3 Equipment and Materials... 4 4 Culture Media and Reagents... 5 5 Inspection Procedure... 5 6 Operation Procedure... 6 7 Results and Reports... 7 Appendix A Culture Media and Reagents... 8ForewordThis Standard replaces "Microbiological Examination of Food Hygiene - Examination of Hemolytic Streptococcus" (GB/T 4789.11-2003). Compared with GB/T 4789.11-2003, this Standard has the following main changes. - The standard name was modified; - The "Scope" was modified; - The "Terms and Definitions" was added; - The "Equipment and Materials" was modified; - The "Culture Media and Reagents" was modified; - The procedure of sample dilution with aseptic normal saline and the bacitracin sensitivity test were deleted; - The catalase test was added; - Appendix A was added. National Food Safety Standard – Food Microbiological Examination – Examination of β-type Hemolytic Streptococcus1 ScopeThis Standard specifies the inspection method for β-type hemolytic streptococcus in foods. This Standard is applicable to inspection of β-type hemolytic streptococcus in foods.2 Terms and Definitions2.1 β-type hemolysis Totally transparent hemolytic rings are formed around the bacterial colony, and the erythrocytes are fully dissolved. 2.2 β-type hemolytic streptococcus It can produce β-type hemolytic streptococcus pyogenes (or A-group) and streptococcus agalactiae (or B-group).3 Equipment and MaterialsIn addition to the conventional sterilization and cultivation equipment in microbiological laboratory, other equipment and materials are as follows.4 Culture Media and Reagents4.1 Modified tryptone soybean broth (mTSB). see A.1 of Appendix A. 4.2 Columbia CNA blood agar. see A.2 of Appendix A. 4.3 Columbia blood agar. see A.3 of Appendix A. 4.4 Gram stain solution. see A.4 of Appendix A. 4.8 3% hydrogen peroxide (H2O2) solution. see A.8 of Appendix A. 4.9 Biochemical identification kit or card.5 Inspection ProcedureThe inspection procedure of hemolytic streptococcus is detailed in Figure 1.6 Operation Procedure6.1 Sample Treatment and Bacteria Enrichment Weigh 25 g (mL) of sample according to aseptic operation; put into a homogenizing bag that contains 225 mL of mTSB; 6.2 Separation The enrichment broth is subject to streak inoculation to the Columbia CNA blood agar plate and anaerobic cultivation under 36°C±1°C for 18 h~24 h, then observe the colony shape. 6.3 Identification 6.3.1 Separable pure cultivation Select five suspicious colonies (if less than five, select all) to inoculate with Columbia blood agar plate and TSB enrichment broth respectively, then cultivate under 36°C±1°C for 18 h~24 h. 6.3.2 Gram stain microscopy Select suspicious colony for gram staining microscopic examination. The β-type hemolytic streptococcus is gram positive, spherical or oval, and generally shaped in short chain. 6.3.4 Streptokinase test (optional item) Suck 0.2 mL of potassium oxalate blood plasma into 0.8 mL of sterilized normal saline and mix well; then add 0.5 mL of TSB culture solution of suspicious colony after cultivation under 36°C±1°C for 18 h~24 h and 0.25 mL of 0.25% calcium chloride solution; oscillate and shake well; place into the water bath of 36°C±1°C for 10 min; 6.3.5 Other inspections Identify the suspicious colony with biochemical identification kit or biochemical identification card.7 Results and ReportsUpon the above test results, report the detected or un-detected hemolytic streptococcus in every 25 g (mL) of samples.Appendix ACulture Media and Reagents A.1 Modified tryptone soybean broth (mTSB) culture medium A.1.1 Basal medium (Tryptone soybean broth [TSB]) A.1.2 Antibiotic solution A.1.2.1 Polymyxin solution Weigh 10 mg of polymyxin B into 10 mL of sterile purified water, shake to mix well, filter and remove bacteria after fully dissolved. A.1.2.2 Nalidixic acid sodium solution Weigh 10 mg of nalidixic acid into 10 mL of sodium hydroxide solution (0.05mol/L), shake to mix well, filter and remove bacteria after fully dissolved. A.1.3 Complete medium A.2.2 Preparation Dissolve the compositions listed in A.2.1 into the distilled water, heat to dissolve, calibrate the pH value to 7.3±0.2 and sterilize at 121°C for 12 min; after cooling to around 50°C, add 50 mL of aseptic defibrinated sheep blood, shake well and pour to the plate. A.3 Columbia blood agar A.3.1 Basal medium A.3.1.1 Compositions Animal tissue zymolyte 23.0 g Starch 1.0 g Sodium chloride 5.0 g Agar 8.0 g~18.0 g Distilled water 1 000.0mL A.4 Gram stain solution A.4.1 Basal medium of crystal violet staining solution A.4.1.1 Compositions Crystal violet 1.0 g 95% ethanol 20.0mL 1% ammonium oxalate solution 80.0 mL A.4.1.2 Preparation Fully dissolve the crystal violet into ethanol, and then mix with ammonium oxalate solution. A.4.2 Gram's iodine solution A.4.2.1 Compositions Iodine 1.0 g Kalium iodide 2.0 g Distilled water 300.0mL A.4.3 Safranin solution A.4.3.1 Compositions Safranin 0.25 g 95% ethanol 10.0mL Distilled water 90.0mL A.4.3.2 Preparation Dissolve safranin into the ethanol, and dilute with distilled water. A.5 Tryptone soybean broth (TSB) A.5.1 Compositions Tryptone 17.0 g Soybean peptone 3.0 g Sodium chloride 5.0 g Potassium dihydrogen phosphate (anhydrous) 2.5 g Glucose 2.5 g Distilled water 1000.0 mL A.6 Potassium oxalate blood plasma A.6.1 Compositions Potassium oxalate 0.01 g Human blood 5.0 mL A.6.2 Preparation Take 0.01 g of potassium oxalate into the small sterilizing test tube, add 5 mL of human blood and mix them well, centrifuge the mixture and make it sediment, and then absorb the supernatant, that is the potassium oxalate blood plasma. A.7 0.25% calcium chloride (CaCl2) solution A.7.1 Compositions Calcium chloride (anhydrous) 22.2 g Distilled water 1000.0 mL ......Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al. Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of English version of GB 4789.11-2014 be delivered?Answer: The full copy PDF of English version of GB 4789.11-2014 can be downloaded in 9 seconds, and it will also be emailed to you in 9 seconds (double mechanisms to ensure the delivery reliably), with PDF-invoice.Question 2: Can I share the purchased PDF of GB 4789.11-2014_English with my colleagues?Answer: Yes. The purchased PDF of GB 4789.11-2014_English will be deemed to be sold to your employer/organization who actually paid for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. 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