GB 4789.9-2025 National food safety standard -Food microbiological examination - Examination of Campylobacter jejuni and Campylobacter coli
1 Scope
This standard specifies the test methods for Campylobacter jejuni and Campylobacter coli in food.
This standard is applicable to the examination of Campylobacter jejuni and Campylobacter coli in food.
2 Equipment and materials
In addition to conventional sterilization, culture, and molecular detection equipment in microbiological laboratories, other equipment and materials are as follows.
2.1 Refrigerator: 2°C to 8°C and -18°C to -20°C.
2.2 Constant temperature incubator: 25°C±1°C, 36°C±1°C, 42℃±1°C.
2.3 Stomacher blender.
2.4 Sterile filter bag for stomacher.
2.5 Electronic balance: sensitivity of 0.1g, 0.01g, 0.001g.
2.6 Constant temperature water bath or metal bath device: 36°C to 100°C.
2.7 Oscillator.
2.8 Sterile petri dishes: diameter of 60 mm, 90 mm.
2.9 Sterile hydrophilic filter membrane: diameter of 47 mm, pore size of 0.45 μm.
2.10 Microaerobic culture device: providing microaerobic conditions (5% oxygen, 10% carbon dioxide, and 85% nitrogen).
2.11 Microscope: 10X to 1 000X.
2.12 Low-temperature high-speed centrifuge: 8 000g to 20 000g, 4°C.
2.13 pH meter or pH colorimetric tube or precision pH test paper.
2.14 Real-time fluorescence PCR instrument.
2.15 Real-time fluorescence PCR reaction tube.
2.16 Micropipette and tips: 0.1μL to 2.5μL, 0.5μL to 10μL, 2μL to 20μL, 20μL to 200μL, 100μL to 1 000μL.
2.17 Sterile centrifuge tubes: 50 mL, 100 mL, or larger capacity.
2.18 Screw-cap tube: 10 mL.
2.19 Sterile inoculation loop: 1μL, 10μL.
2.20 Sterile pipettes: 1 mL (with 0.01 mL graduations), 10 mL (with 0.1 mL graduations).
2.21 Microbial biochemical identification system.
2.22 Matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOF MS).
3 Culture media and reagents
3.1 0.1% peptone water: See A.1 in Annex A.
3.2 Sterile physiological saline: See A.2.
3.3 Campylobacter enrichment broth: See A.3.
3.4 Columbia blood agar: See A.4.
3.5 Karmali blood agar: See A.5.
3.6 Oxidase reagent: See A.6.
3.7 3% hydrogen peroxide (H2O2) solution: See A.7.
3.8 Indoxyl acetate strips: See A.8.
3.9 1 mol/L sodium thiosulfate (Na2S2O3) solution: See A.9.
3.10 Sodium hippurate hydrolysis reagents: See A.10.
3.11 Microbial biochemical identification kit or microbial biochemical identification system reagents.
3.12 Real-time fluorescence PCR detection kit or detection reagents (2× Real-time fluorescence PCR buffer, dNTPs, Taq DNA polymerase, and sterilized deionized water).
3.13 Campylobacter jejuni reference strain [NPRC(S)01.13897] or other equivalent strains.
3.14 Campylobacter coli reference strain [NPRC(S)01.13898] or other equivalent strains.
3.15 Campylobacter upsaliensis reference strain [NPRC(S)01.13899] or other equivalent strains.
3.16 Campylobacter lari reference strain [NPRC(S)01.13900] or other equivalent strains.
4 Examination procedures
Contents
Foreword i
1 Scope
2 Equipment and materials
3 Culture media and reagents
4 Examination procedures
5 Procedures
6 Results and report
Annex A Culture media and reagents
