Decimal Reduction Time Phage Therapy Calculator

∞ generated and posted on 2022.06.06 ∞

The time it takes to reduce a bacterial population by 90% as a function of phage concentrations, bacterial concentrations, and the phage adsorption rate constant.

Please cite as:

Stephen T. Abedon
Decimal Reduction Time Phage Therapy Calculator.
decimal.phage-therapy.org

Click here for calculator or see immediately below for further explanation and discussion.

This calculator determines not just deciminal reduction times but also various log₁₀ reduction times beyond just log₁₀(1), e.g., such as 100-fold reductions (a.k.a., "2-log₁₀", which is a 0.99 reduction).

Determined are reduction times ignoring free phage losses to bacterial adsorption (thereby ignoring bacterial concentrations), that is, with free phage replacment there is "No decline in free phage numbers due to adsorption".

This contrasts with reduction times taking into account free phage losses to bacterial adsorption where there is a "Decline in free phage numbers due to adsorption".

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For further discussion, see:

Abedon, S.T. (2011). Phage therapy pharmacology: calculating phage dosing. Advances in Applied Microbiology 77:1-40.

See also the Bacterial Half-Life Calculator and the Inundative Phage Density Calculator.

Calculate Decimal Reduction Time

Concentration of Phages per ml (m × 10ⁿ):
(significand, m) = m
above is set to 1 if left blank or not number or ≤ 0
(exponent, 10ⁿ) = n
above is set to 0 if left blank or not number or < 0

Concentration of Bacteria per ml (m × 10ⁿ):
(significand, m) = m
above is set to 1 if left blank or not number or ≤ 0
(exponent, 10ⁿ) = n
above is set to 0 if left blank or not number or < 0

Adsorption Rate Constant (k as m × 10ⁿ):
(significand, m) = m
above is set to 2.5 if left blank or not number or ≤ 0
(exponent, 10ⁿ) = n
above is set to -9 if left blank or not number or > 0

k value is defaulted at 2.5 × 10^-9 ml^-1 min^-1 from Stent (1963)
may be greater or lower but must be defined to calculate MOI_actual
the larger the number, the faster the phage adsorption

Optional Alternative Reduction:
(e.g., 0.999)
above must be > 0 and < 1
note that 0.999 = 1 - 0.001
i.e., reduction = 1 - survival