{"topic_id":"EFSA_FEEDAP_lcystine_safety","category":"efsa","context":"---\ntopic_id: EFSA_FEEDAP_lcystine_safety\ncategory: efsa\ntitle: \"EFSA FEEDAP — L-cystine (E. coli DSM 34232) for all animal species: safe; strain has two acquired AMR genes but no viable cells/DNA in product (EFSA Journal 2025;23(10))\"\nlang: en\nsource: \"EFSA FEEDAP scientific opinion, EFSA Journal 2025;23(10) (DOI 10.2903/j.efsa.2025.9688)\"\nsource_file: pdf-raw/efsa_l/cystine_aa.xml\nsource_type: journal_article\ndate_parsed: 2026-08-06\ntokens_estimated: 460\nverified: true\nverification:\n  method: paraphrase\n  claims: 5\n  passed: 5\n  date: 2026-08-06\nsource_document: \"EFSA FEEDAP — L-cystine (E. coli DSM 34232) for all animal species: safe; strain has two acquired AMR genes but no viable cells/DNA in product (EFSA Journal 2025;23(10))\"\ncitation:\n  authority: \"EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP)\"\n  title: \"EFSA FEEDAP — L-cystine (E. coli DSM 34232) for all animal species: safe; strain has two acquired AMR genes but no viable cells/DNA in product (EFSA Journal 2025;23(10))\"\n  url: \"https://doi.org/10.2903/j.efsa.2025.9688\"\n  retrieved: \"2026-08-06\"\n  ref: \"EFSA Journal 2025;23(10)\"\n  doc_type: \"EFSA scientific opinion (Europe PMC OA full-text XML)\"\n  needs_review: false\nauthority_tier: T1\nauthority_tier_basis: \"T1:eu-body\"\nauthority_tier_date: 2026-08-06\n---\n# EFSA FEEDAP — L-cystine (E. coli DSM 34232) for all animal species\n\nSource: EFSA FEEDAP scientific opinion, EFSA Journal 2025;23(10) (DOI 10.2903/j.efsa.2025.9688), retrieved 2026-08-06 via Europe PMC OA full-text XML. Paraphrase of an EFSA opinion that the source XML tags CC-BY-ND; per project COPYRIGHT_POLICY only facts/numbers/proper-nouns are quoted verbatim, sentences rewritten.\n\n## Editorial context (read this before using the data point)\n\nThis is the **EFSA FEEDAP** jurisdiction on the amino-acid feed additive **L-cystine (E. coli DSM 34232)** — one of four amino-acid safety opinions in this batch (Task L). Read with the `efsa` nutrient endpoints and AAFCO/FEDIAF amino-acid provisions.\n\n## Key findings (paraphrase; numbers and proper nouns verbatim from source)\n\n- Production strain **E. coli DSM 34232 harbours two acquired AMR (antimicrobial-resistance) genes**, but **no viable cells or DNA** of the strain were detected in the final product, so the strain raises no safety concern.\n- The additive is **safe for target species, consumers and the environment** at the proposed conditions of use.\n- **User safety**: not a skin/eye irritant and not a skin sensitiser.\n- Because L-cystine is used as a **flavouring compound in food**, the Panel expects a similar function in feed and requires no further efficacy demonstration.\n\n## Pet-food relevance\n\nCystine (the oxidised dimer of cysteine) is relevant to sulphur-amino-acid nutrition in cats and dogs. The explicit AMR-gene disclosure with the 'no viable cells/DNA → no safety concern' resolution is the notable honesty point; the safe-for-all-species conclusion is the usable data point.\n\n## Scope note / honest gap\n\nParaphrase of an EFSA opinion; source XML licence tag was CC-BY-ND, so this topic quotes only data points verbatim and rewrites prose. Full strain-characterisation and tolerance statistics are not reproduced.\n","sources":["OFT3 — EFSA FEEDAP — L-cystine (E. coli DSM 34232) for all animal species: safe; strain has two acquired AMR genes but no viable cells/DNA in product (EFSA Journal 2025;23(10)) (retrieved 2026-08-06)"],"source":{"authority":"OFT3","title":"EFSA FEEDAP — L-cystine (E. coli DSM 34232) for all animal species: safe; strain has two acquired AMR genes but no viable cells/DNA in product (EFSA Journal 2025;23(10))","url":"https://doi.org/10.2903/j.efsa.2025.9688","retrieved":"2026-08-06","ref":"","doc_type":"official PDF","source_document":"EFSA FEEDAP — L-cystine (E. coli DSM 34232) for all animal species: safe; strain has two acquired AMR genes but no viable cells/DNA in product (EFSA Journal 2025;23(10))","verification_file":"pdf-raw/efsa_l/cystine_aa.xml"},"source_document":"EFSA FEEDAP — L-cystine (E. coli DSM 34232) for all animal species: safe; strain has two acquired AMR genes but no viable cells/DNA in product (EFSA Journal 2025;23(10))","source_file":"pdf-raw/efsa_l/cystine_aa.xml","trust":{"authority_tier":"T1","fidelity":"paraphrase","license":null,"display_grade":"C"},"tokens_estimated":450,"generated_at":null,"tip":"Use /api/v1/topics to discover more topics. /api/v1/nutrient for precise single-point queries. /api/v1/cross_compare for 2-3 standard comparisons."}