minimum bactericidal concentration

Declared killing threshold

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/).

1. Does this result use the conventional ≥99.9% reduction from the initial viable inoculum, or another explicitly documented criterion? definition
2. Which source and method version establish what MBC means in this report? provenance

Viability versus inhibition

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.

1. Was the endpoint established from recoverable survivors or inferred only from absent turbidity? boundary
2. Is the reported quantity a concentration at a fixed exposure duration, rather than a killing time, biofilm eradication concentration or sterilisation claim? boundary

Agent-isolate specificity

Record the antimicrobial concentration basis and bacterial isolate, including population states that limit comparison with other measurements.

1. Which antimicrobial, formulation or defined mixture was tested, and what does its concentration unit quantify? measurement
2. Which isolate and population state were exposed, and how was the initial viable inoculum established? provenance

Method applicability

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/).

1. What exposure duration, medium, temperature and atmosphere define this result? measurement
2. Which concentrations were tested, and does the cited method cover this organism and population state? boundary

Resolvable log reduction

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.

1. What viable counts support the initial and post-exposure concentrations, and what reduction follows from them? measurement
2. If no colonies were recovered, does the sampled volume support the required reduction rather than merely a nondetection statement? measurement

Carryover and recovery controls

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/).

1. What evidence shows that residual antimicrobial did not suppress colony recovery? measurement
2. Do recovery controls support survivor detection under the chosen recovery conditions and any dilution, removal or neutralisation step? measurement
3. Should failed controls trigger rejection of the endpoint or additional measurement? action

Lowest supported concentration

Identify the lowest tested concentration satisfying the declared criterion under the adopted method. Preserve range censoring, replicate disagreement and nonmonotonic survivor patterns for review.

1. Which tested concentration first satisfies the criterion, and what evidence establishes failure at lower tested concentrations? measurement
2. Do assay limits, discordant replicates or unexpected survivor patterns require a bounded, indeterminate or repeated result? action

Paired MIC and interpretive limits

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/).

1. Were the MBC and MIC obtained for the same agent and isolate under compatible conditions, and are either values censored? boundary
2. What evidence supports any tolerance label or other biological interpretation assigned from the ratio? provenance
3. What additional evidence is required before using this laboratory endpoint to support a clinical decision? action

Check these first

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these check these first hold for the sense of minimum bactericidal concentration this model covers, and on what evidence? provenance

Standards and regulation

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these standards and regulation hold for the sense of minimum bactericidal concentration this model covers, and on what evidence? provenance

Real-world use

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these real-world use hold for the sense of minimum bactericidal concentration this model covers, and on what evidence? provenance

Typical measurements

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these typical measurements hold for the sense of minimum bactericidal concentration this model covers, and on what evidence? provenance

Failure modes and hazards

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these failure modes and hazards hold for the sense of minimum bactericidal concentration this model covers, and on what evidence? provenance

Neighbouring kinds and how to tell them apart

Recalled without web access and unsourced; every item is a lead to verify.

1. 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? provenance