gram variable

Edge evidence

• culture aging regulates peptidoglycan thinning RO:0002211

  Aging cultures undergo cell-wall thinning via autolysis.

  • DOI:10.1128/CMR.00043-07 autolysis Supports autolysis-driven peptidoglycan thinning in aging cultures.
• peptidoglycan thinning causes crystal-violet retention loss biolink:causes

  Thinned peptidoglycan no longer retains the gram-stain dye.

  • DOI:10.1128/CMR.00043-07 crystal violet Supports peptidoglycan thickness as the determinant of crystal-violet retention in the gram-stain protocol.
• crystal-violet retention loss produces mixed-population gram staining METPO:2000202

  Subpopulations with reduced dye retention appear gram-negative alongside intact gram-positive cells.

  • DOI:10.1128/CMR.00043-07 decolorization Supports differential decolorization producing mixed staining within a single culture.
• mixed-population gram staining manifests as gram variable METPO:2007400

  Mixed staining manifests the gram-variable trait.

  • DOI:10.1128/CMR.00043-07 Gram-variable Supports the Gram-variable phenotype as the trait endpoint of heterogeneous staining.
• thin peptidoglycan layer results in gram-negative staining

  A thin peptidoglycan layer can yield a gram-negative staining result even in monoderm bacteria.

  • DOI:10.1128/spectrum.00732-24 certain bacteria can stain Gram-negative despite having a monoderm cell wall structure
• thin peptidoglycan layer reduces CV-iodide complex retention METPO:2000017

  A thin peptidoglycan layer reduces retention of the crystal-violet-iodide complex, the core staining-chemistry determinant.

  • DOI:10.1128/spectrum.00732-24 to retain the CV-iodide complex, resulting in the loss of the CV
• CV-iodide complex retention regulates crystal-violet retention loss RO:0002211

  Reduced CV-iodide complex retention drives loss of crystal-violet retention.

  • DOI:10.1128/spectrum.00732-24 Reduced CV-iodide complex retention underlies the loss of crystal violet during decolorization.
• cell wall-deficient forms produces mixed-population gram staining METPO:2000202

  Stress-induced cell wall-deficient forms can produce mixed gram reactions within a single culture.

  • DOI:10.1101/2023.11.16.566987 mechanisms that can produce cell-wall alterations or loss that would lead to mixed Gram reactions in a single culture