GB/T 14926.1-2026 Laboratory animal—Method for examination of Salmonella spp. English, Anglais, Englisch, Inglés, えいご
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ICS 13.220.10
CCS H 57
National Standard of the People's Republic of China
GB/T 14926.1-2026
Replaces GB/T 14926.1-2001
Laboratory animal - Method for examination of Salmonella spp.
实验动物 沙门菌检测方法
Issue date: 2026-01-28 Implementation date: 2027-02-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
Introduction
1 Scope
2 Normative References
3 Terms and Definitions
4 Principle
5 Main Equipment
6 Culture Media and Reagents
7 Detection Procedure
8 Operating Steps
9 Result Reporting
Laboratory Animals — Detection Method for Salmonella spp.
1 Scope
This document describes the detection method for Salmonella spp. in laboratory animals.
This document applies to the detection of Salmonella spp. in laboratory animals such as mice, rats, guinea pigs, hamsters, rabbits, dogs, monkeys, etc.
2 Normative References
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB 4789.4-2024 National Food Safety Standard – Microbiological examination of food – Examination of Salmonella spp.
GB/T 14926.42-2001 Laboratory animal – Bacteriological examination – Collection of specimens
GB/T 14926.43-2001 Laboratory animal – Bacteriological examination – Staining, media and reagents
3 Terms and Definitions
No terms and definitions are required for this document.
4 Principle
Salmonella spp. exhibit specific growth, morphological, physiological, and biochemical characteristics on culture media. Somatic (O) antigens react with corresponding antibodies, causing agglutination. Common Salmonella serotypes in laboratory animals within the genus possess unique genomic nucleic acid sequences, which can be identified by nucleic acid amplification techniques such as Polymerase Chain Reaction (PCR).
5 Main Equipment
5.1 Incubator.
5.2 Real-time fluorescence nucleic acid amplification instrument.
5.3 Microbial biochemical identification system.
6 Culture Media and Reagents
6.1 Reagents for Culture Method
6.1.1 Selenite F enrichment broth (SF).
6.1.2 Cary-Blair transport medium.
6.1.3 Deoxycholate hydrogen sulfide lactose agar (DHL).
6.1.4 Xylose lysine deoxycholate agar (XLD).
6.1.5 Triple sugar iron agar (TSI).
6.1.6 Sugar fermentation media.
6.1.7 Lysine decarboxylase medium.
6.1.8 Potassium cyanide medium (KCN).
6.1.9 Peptone water, Kovac's reagent (for indole test).
6.1.10 Polyvalent Salmonella diagnostic sera.
6.1.11 Nutrient agar (NA).
6.1.12 Urea agar (pH 7.2).
6.1.13 Ortho-nitrophenyl-β-D-galactopyranoside medium (ONPG).
6.1.14 Sodium malonate medium.
6.2 Reagents for Nucleic Acid Amplification Method
6.2.1 DEPC-treated nuclease-free water.
6.2.2 Bacterial genomic nucleic acid extraction reagents or kit.
6.2.3 Real-time fluorescence quantitative RT-PCR master mix (basal reaction solution).
6.2.4 Positive control: Inactivated animal sample containing Salmonella nucleic acid.
6.2.5 Negative control: Animal sample not containing Salmonella nucleic acid.
6.2.6 Primers and probes: Synthesize primers and probes according to the sequences in
Table 1. Prepare primers and probes as 10 μmol/L stock solutions and store below -20°C.
7 Detection Procedure
The detection procedure is shown in Figure 1.
8 Operating Steps
8.1 Culture Method
8.1.1 Reagent Preparation
Prepare culture media and other reagents required for testing according to GB/T 14926.43-2001 and the appendices of GB 4789.4-2024.
8.1.2 Sampling
Collect cecal contents, feces, or rectal/anal swabs from laboratory animals according to the requirements of GB/T 14926.42-2001. If samples cannot be inoculated directly for culture, they shall be placed in transport medium and transported to the laboratory.
8.1.3 Isolation Culture
8.1.3.1 Direct Isolation Culture
Inoculate cecal contents, feces, or anal swabs (when sample quantity is sufficient) directly by streaking onto DHL agar plates or XLD agar plates. Incubate at 36°C ± 1°C for 18 h to 24 h.
8.1.3.2 Enrichment Isolation Culture
When the quantity of collected cecal contents, feces, or anal swabs is small, enrichment treatment may be chosen. Inoculate the specimen sample into SF enrichment broth and incubate overnight at 36°C ± 1°C. Take 10 μL or one full loop of inoculum from the enrichment broth and inoculate onto the isolation medium.
8.1.4 Identification
8.1.4.1 Colony Characteristics
On DHL agar, colonies appear colorless, translucent, with a black center or almost entirely black. On XLD agar, colonies appear pink with or without a black center; some colonies may appear entirely black; some strains may appear yellow with or without a black center.
8.1.4.2 Cellular Characteristics
Gram-negative rods, no spores, no capsule.
8.1.4.3 Biochemical Characteristics
Perform biochemical reactions according to the provisions of 5.4 in GB 4789.4-2024, or use an automated bacterial identification system or commercial identification kits.
8.1.4.4 Slide Agglutination Test
Perform agglutination tests with polyvalent somatic (O) antigen sera according to the provisions of 5.5.2 in GB 4789.4-2024 for determination.
8.1.5 Application of Automated Microbial Biochemical Identification System
Suspicious colonies on isolation or differential media may be subsequently identified using an automated microbial biochemical identification system.
8.2 Nucleic Acid Amplification Detection
When necessary, molecular pathogenetic methods may be used, applying PCR technology to amplify specific sequences characteristic of Salmonella.
Extract genomic nucleic acid from samples obtained from laboratory animals or from colonies isolated by the culture method, and perform nucleic acid amplification for Salmonella according to the method in Appendix A.
9 Result Reporting
A positive result shall be reported for specimens conforming to all the above-mentioned test results. A negative result shall be reported for specimens not conforming.
