Re-suspension of T144 vaccine cultures of Mycoplasma mycoides subsp. mycoides SC in 1 molar MgSO4 causes a drop in pH and a rapid reduction in titre

5Citations
Citations of this article
9Readers
Mendeley users who have this article in their library.

Abstract

The effect of reconstituting freeze-dried vaccine cultures of Mycoplasma mycoides subsp. mycoides small colony biotype (MmmSC) strain T144 grown in standard vaccine medium using variable quantities of un-buffered solutions of 1 M MgSO4 (the current O.I.E.-recommended procedure) has been investigated. Compared to the culture pH prior to desiccation, a drop of up to 2.2 pH units was observed, dependent upon the volume and pH of 1 M MgSO4 used (1-30× original culture volume, using 1 M MgSO4 in the pH range 5.4-7.6). This pH drop appears to be due to the removal of the HPO42- buffer capacity of the medium by the formation of insoluble Mg3(PO4)2 and the release of free H+ ions. As a result of this lower pH, markedly reduced culture viability was observed over an 8-h period at 37°C for vaccines re-suspended in 1 M MgSO4 (ca. 6 log10 drop in titre) compared to re-suspension in dH2O (ca. 1.5 log10 drop in titre). Re-suspension in 1 M MgSO4 did exhibit a thermoprotective effect at 46°C, but only when the pH was maintained above pH 7.0 by use of HEPES-buffered growth medium (1 log10 drop in titre compared to 6 log10 drop using dH2O over an 8-h period). Since all current O.I.E.-recommended growth media for MmmSC are based upon a phosphate buffer system, it is therefore recommended that the use of 1 M MgSO4 as a reconstitution fluid be discontinued as soon as possible and buffered saline be used instead. The use of this reconstitution procedure with the T144 vaccine strain could be a significant factor in the poor efficacy observed with current freeze-dried vaccines against contagious bovine pleuropneumonia in Africa. © 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.

Cite

CITATION STYLE

APA

March, J. B., Waite, E. R., & Litamoi, J. K. (2002). Re-suspension of T144 vaccine cultures of Mycoplasma mycoides subsp. mycoides SC in 1 molar MgSO4 causes a drop in pH and a rapid reduction in titre. FEMS Immunology and Medical Microbiology, 34(2), 97–103. https://doi.org/10.1016/S0928-8244(02)00372-3

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free