{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.minimum-bactericidal-concentration","code":"thing-q1158816","url":"https://ver.cy/models/thing/q1158816/","name":"minimum bactericidal concentration","alternateNames":[],"kind":"thing","status":"published","version":"0.1.0-research.1","language":"en","classifiers":{"family":"Thing Registry","category":"Cross-cutting context","entryKind":"thing","plane":"XCT","domain":["XCT.QLT"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"Minimum bactericidal concentration (MBC) is the lowest concentration of an antibacterial agent that reduces the viable count of a specified bacterial inoculum by at least 99.9% under defined in vitro test conditions.","purpose":"Enable an agent to recognise, assess and compare a minimum bactericidal concentration result by connecting its killing endpoint to the bacterial population, antimicrobial exposure and evidence supporting it.","scope":{"in":["Operational definition of the bactericidal endpoint and its reference population","Antimicrobial identity, bacterial isolate and physiological state to which the result applies","Exposure conditions, tested concentrations and recovery method","Survivor evidence, detection limits and endpoint validity","Qualified comparison with paired minimum inhibitory concentration results"],"out":["Complete antimicrobial substance identity, manufacture and formulation models","Bacterial taxonomy and comprehensive isolate characterisation","Minimum inhibitory concentration as an independently modelled inhibition endpoint","Time-kill kinetics and minimum duration for killing as independent measures","Biofilm eradication and sterilisation endpoints","Patient-specific dosing, treatment selection and clinical susceptibility breakpoints"],"boundaries":[]},"distinguishingFeatures":["Requires evidence of loss of recoverable viability; absence of visible growth alone establishes inhibition rather than the bactericidal endpoint.","Expresses an antimicrobial concentration at a specified exposure duration, rather than the time required to achieve killing.","Uses a stated reduction relative to the initial viable inoculum; the conventional 99.9% threshold does not require elimination of every bacterium.","Belongs to an antimicrobial-bacterial population-method combination, rather than being an unconditional property of an antimicrobial.","A zero-colony recovery result supports the endpoint only when sampling sensitivity and recovery controls can substantiate the required reduction."],"structure":{"bundles":[{"id":"bactericidal-endpoint","name":"Bactericidal endpoint","description":"Defines what the concentration claims to establish and which registered concept it instantiates.","layers":[{"id":"operational-definition","name":"Operational definition","description":"Makes the killing threshold and terminology explicit.","findings":[{"id":"declared-killing-threshold","name":"Declared killing threshold","description":"Record the adopted definition rather than treating all historical labels as equivalent. One experimental paper distinguished an MBC requiring no visible plate growth from a minimal lethal concentration requiring 99.9% killing. [Original study](https://pubmed.ncbi.nlm.nih.gov/102246/).","questions":[{"text":"Does this result use the conventional ≥99.9% reduction from the initial viable inoculum, or another explicitly documented criterion?","id":"declared-killing-threshold-q01","kind":"definition"},{"text":"Which source and method version establish what MBC means in this report?","id":"declared-killing-threshold-q02","kind":"provenance"}]}]},{"id":"endpoint-boundaries","name":"Endpoint boundaries","description":"Separates killing evidence from neighbouring measurements.","findings":[{"id":"viability-versus-inhibition","name":"Viability versus inhibition","description":"Require a survivor-based endpoint and retain its relationship to any inhibition measurement; a clear exposure broth is not sufficient evidence of the required viability reduction.","questions":[{"text":"Was the endpoint established from recoverable survivors or inferred only from absent turbidity?","id":"viability-versus-inhibition-q01","kind":"boundary"},{"text":"Is the reported quantity a concentration at a fixed exposure duration, rather than a killing time, biofilm eradication concentration or sterilisation claim?","id":"viability-versus-inhibition-q02","kind":"boundary"}]}]}]},{"id":"agent-population-exposure","name":"Agent, population and exposure","description":"Binds the MBC to the tested antimicrobial, bacteria and exposure conditions.","layers":[{"id":"tested-pair","name":"Tested pair","description":"Identifies the chemical exposure and biological population.","findings":[{"id":"agent-isolate-specificity","name":"Agent-isolate specificity","description":"Record the antimicrobial concentration basis and bacterial isolate, including population states that limit comparison with other measurements.","questions":[{"text":"Which antimicrobial, formulation or defined mixture was tested, and what does its concentration unit quantify?","id":"agent-isolate-specificity-q01","kind":"measurement"},{"text":"Which isolate and population state were exposed, and how was the initial viable inoculum established?","id":"agent-isolate-specificity-q02","kind":"provenance"}]}]},{"id":"exposure-frame","name":"Exposure frame","description":"Captures duration, environment and the sampled concentration range.","findings":[{"id":"method-applicability","name":"Method applicability","description":"Record the actual conditions and justify the method's applicability. CLSI M26 describes methods intended primarily for aerobic bacteria growing in specified broth conditions; its scope should not be silently extended to other populations. [CLSI M26](https://clsi.org/shop/standards/m26/).","questions":[{"text":"What exposure duration, medium, temperature and atmosphere define this result?","id":"method-applicability-q01","kind":"measurement"},{"text":"Which concentrations were tested, and does the cited method cover this organism and population state?","id":"method-applicability-q02","kind":"boundary"}]}]}]},{"id":"survivor-evidence","name":"Survivor evidence","description":"Connects recovered viable counts to the killing claim and evaluates measurement artefacts.","layers":[{"id":"reduction-and-resolution","name":"Reduction and resolution","description":"Makes the numerical evidence and assay sensitivity inspectable.","findings":[{"id":"resolvable-log-reduction","name":"Resolvable log reduction","description":"Retain initial and recovered viable concentrations, dilution factors and sampled volumes. Calculate log10(N0/Nt) when both values are quantifiable; use a detection-limit bound when no survivors are recovered.","questions":[{"text":"What viable counts support the initial and post-exposure concentrations, and what reduction follows from them?","id":"resolvable-log-reduction-q01","kind":"measurement"},{"text":"If no colonies were recovered, does the sampled volume support the required reduction rather than merely a nondetection statement?","id":"resolvable-log-reduction-q02","kind":"measurement"}]}]},{"id":"recovery-validity","name":"Recovery validity","description":"Assesses whether survivors could have been detected reliably.","findings":[{"id":"carryover-and-recovery-controls","name":"Carryover and recovery controls","description":"Residual antimicrobial can suppress recovery and exaggerate killing. Experimental work found that antimicrobial carryover reduced recovered viable counts, with effects dependent on transferred sample volume. [Original methods study](https://pubmed.ncbi.nlm.nih.gov/105628/).","questions":[{"text":"What evidence shows that residual antimicrobial did not suppress colony recovery?","id":"carryover-and-recovery-controls-q01","kind":"measurement"},{"text":"Do recovery controls support survivor detection under the chosen recovery conditions and any dilution, removal or neutralisation step?","id":"carryover-and-recovery-controls-q02","kind":"measurement"},{"text":"Should failed controls trigger rejection of the endpoint or additional measurement?","id":"carryover-and-recovery-controls-q03","kind":"action"}]}]}]},{"id":"endpoint-judgement","name":"Endpoint judgement","description":"Turns the concentration series into a qualified result and governs its interpretation.","layers":[{"id":"selection-and-uncertainty","name":"Selection and uncertainty","description":"Selects the endpoint without inventing precision or hiding inconsistent observations.","findings":[{"id":"lowest-supported-concentration","name":"Lowest supported concentration","description":"Identify the lowest tested concentration satisfying the declared criterion under the adopted method. Preserve range censoring, replicate disagreement and nonmonotonic survivor patterns for review.","questions":[{"text":"Which tested concentration first satisfies the criterion, and what evidence establishes failure at lower tested concentrations?","id":"lowest-supported-concentration-q01","kind":"measurement"},{"text":"Do assay limits, discordant replicates or unexpected survivor patterns require a bounded, indeterminate or repeated result?","id":"lowest-supported-concentration-q02","kind":"action"}]}]},{"id":"qualified-use","name":"Qualified use","description":"Constrains comparison and downstream interpretation.","findings":[{"id":"paired-mic-and-interpretive-limits","name":"Paired MIC and interpretive limits","description":"Require compatible paired measurements before calculating an MBC-to-MIC ratio, and document any rule used to interpret it. Clinical inference needs separate evidence: CLSI M26 notes limitations in clinical correlations and the contribution of host factors. [CLSI M26](https://clsi.org/shop/standards/m26/).","questions":[{"text":"Were the MBC and MIC obtained for the same agent and isolate under compatible conditions, and are either values censored?","id":"paired-mic-and-interpretive-limits-q01","kind":"boundary"},{"text":"What evidence supports any tolerance label or other biological interpretation assigned from the ratio?","id":"paired-mic-and-interpretive-limits-q02","kind":"provenance"},{"text":"What additional evidence is required before using this laboratory endpoint to support a clinical decision?","id":"paired-mic-and-interpretive-limits-q03","kind":"action"}]}]}]},{"id":"evidence-and-external-alignment","name":"Evidence and external alignment","description":"What the world already says about this thing, gathered so the model can be checked against it.","layers":[{"id":"reported-evidence","name":"Reported evidence","description":"Findings from the breadth pass, kept separate from the structural claims.","findings":[{"id":"evidence-confidence-notes","name":"Check these first","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these check these first hold for the sense of minimum bactericidal concentration this model covers, and on what evidence?","id":"evidence-confidence-notes-q01","kind":"provenance"}]},{"id":"evidence-standards-and-regulation","name":"Standards and regulation","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these standards and regulation hold for the sense of minimum bactericidal concentration this model covers, and on what evidence?","id":"evidence-standards-and-regulation-q01","kind":"provenance"}]},{"id":"evidence-real-world-use","name":"Real-world use","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these real-world use hold for the sense of minimum bactericidal concentration this model covers, and on what evidence?","id":"evidence-real-world-use-q01","kind":"provenance"}]},{"id":"evidence-measurements","name":"Typical measurements","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these typical measurements hold for the sense of minimum bactericidal concentration this model covers, and on what evidence?","id":"evidence-measurements-q01","kind":"provenance"}]},{"id":"evidence-failure-modes-and-hazards","name":"Failure modes and hazards","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these failure modes and hazards hold for the sense of minimum bactericidal concentration this model covers, and on what evidence?","id":"evidence-failure-modes-and-hazards-q01","kind":"provenance"}]},{"id":"evidence-neighbours","name":"Neighbouring kinds and how to tell them apart","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these neighbouring kinds and how to tell them apart hold for the sense of minimum bactericidal concentration this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Explain what MBC measures and how it differs from the minimum inhibitory concentration.","Record and report MBC results from an authorized laboratory with method, strain and conditions."],"mustNot":["Choose or change a patient's antibiotic treatment in place of a clinician.","Report an MBC without the organism, agent, method and kill threshold used.","Alter, round or fabricate laboratory results.","Present in-vitro values as proof of clinical cure."],"requiresHuman":["Treatment decisions for a patient that rely on the result."]},"ethics":{"considerations":["Misread results can lead to failed treatment or needless antibiotic use that drives resistance."],"affectedParties":["Patients with infections","Clinicians","The public affected by antimicrobial resistance"]},"owners":{"steward":"The testing laboratory answers for each result.","roles":[],"masterSystems":[]},"relations":[{"target":"Q71759392","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.minimum-bactericidal-concentration","Wikidata: Q1158816 (https://www.wikidata.org/wiki/Q1158816)"]},"properties":{"applicability":"not-applicable","items":["Reported concentration endpoint: mg/L or µg/mL; alternatively a justified concentration unit with an explicit substance basis","Endpoint qualification: resolved on tested grid | at or below lowest tested concentration | above highest tested concentration | indeterminate | invalid","Killing criterion: Required percentage reduction or log10 reduction; conventionally ≥99.9% or ≥3 log10","Antimicrobial and target population: Links to agent or defined mixture, bacterial isolate and tested population state","Exposure duration: Hours or minutes, as specified by the method","Initial viable inoculum: CFU/mL with measurement method and uncertainty","Exposure and recovery conditions: Medium, temperature, atmosphere, population state, recovery medium and recovery duration","Survivor concentration and detection limit: CFU/mL, with recovered volume, dilution and counting limits","Paired MBC-to-MIC ratio: Dimensionless ratio, interval or bound from compatible paired measurements"]},"recognition":{"applicability":"optional","items":["Reported as a concentration, often in micrograms per millilitre, alongside an MIC for the same strain."]},"capabilities":{"applicability":"required","items":["Determine whether a reported concentration satisfies the declared bactericidal endpoint.","Calculate viable-count reduction and identify the lowest qualifying tested concentration.","Represent unresolved endpoints as bounds or indeterminate results.","Flag inadequate sampling sensitivity, residual antimicrobial effects or failed recovery controls.","Compare results after checking organism, exposure, endpoint and unit compatibility.","Relate an MBC to a paired MIC while preserving limits on biological and clinical interpretation."]},"hazards":{"applicability":"required","items":["Method differences between laboratories make values hard to compare.","Over-reliance on in-vitro killing can mislead treatment of serious infections."]},"interfaces":{"applicability":"required","items":["CLSI M26-A, Methods for Determining Bactericidal Activity of Antimicrobial Agents, Clinical and Laboratory Standards Institute."]},"context":{"applicability":"required","items":["Minimum bactericidal concentration is used in microbiology laboratories and antimicrobial research to describe bacterial killing under defined test conditions.","It supports comparisons between antibacterial agents or bacterial isolates when test methods and exposure conditions are comparable.","It is interpreted alongside other evidence because an in vitro killing endpoint does not by itself establish clinical effectiveness."]}},"sources":[{"title":"Wikidata item Q1158816: minimum bactericidal concentration","url":"https://www.wikidata.org/wiki/Q1158816","note":"identity and sense of the item"},{"title":"Wikipedia: Minimum bactericidal concentration","url":"https://en.wikipedia.org/wiki/Minimum_bactericidal_concentration","note":"general description of the item"}],"openQuestions":["Which operational definition and method edition should govern this registry entry, and how should historically different uses of MBC and minimal lethal concentration be mapped?","Which organism classes and physiological states require method-specific extensions rather than direct reuse of conventional planktonic MBC procedures?","What sampling sensitivity, replicate agreement and recovery-control criteria are sufficient for accepting a ≥3 log10 reduction in each supported method?","How should nonmonotonic concentration-survival patterns and discordant repeated endpoints be represented and adjudicated?","For which antimicrobial-organism contexts are MBC-to-MIC interpretations or clinical uses adequately validated?"],"resources":{"spec":"/models/things/publications/thing-q1158816/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q1158816/spec.json"],"providers":["Codex"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T11:20:45Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"not-applicable","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-07T10:10:25+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass","interaction.properties":"Plane XCT: no invented physical properties."},"score":1.0}}