A Mathematical Expression for Oxygen-induced Death in Dehydrated Bacteria

Cox, C. S.; Baxter, Jean; Maidment, B. J.

doi:10.1099/00221287-75-1-179

Cited by 14 publications

(10 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results presented in Fig. 1 through 4 and were analyzed by a curve-fitting procedure as n of described before (15), but in terms of equation 9 . at (see Appendix):…”

Section: Discussionmentioning

confidence: 99%

“…Escherichia coli B, E. coli commune, and E. coli Jepp were grown, aerosolized as a suspension in distilled water, sampled, and assayed as previously (6,7), except that aerosols were stored in nitrogen (>99.9%) at a smaller number of relative humidities (RH) and were sampled at storage times of 2, 5, 10, 15, 20, 25, and 30 min. Semliki forest virus (SFV) was studied as before (3), except that aerosols were generated from a suspension of the virus in medium 199 + 10% (vol/vol) calf serum and were stored at a larger number of RH values and for shorter periods of time.…”

Section: Methodsmentioning

confidence: 99%

“…Loss of viability of populations of a given microbe can occur by several different death mechanisms (2, 6-10, 15-17, 19-23), and the same death mechanism can result from apparently different stresses; e.g., aerosolization and freeze-drying can both result in the same oxygen-induced death mechanism (15,17) and also in the same shear-induced death mechanism (19). Furthermore, a given death mechanism does not necessarily occur for all microbial species; e.g., following dehydration, oxygen can kill Serratia marcescens (15,17) but not Bacillus subtilis spores (6) or coliphages T3 and T7 (19). The present paper considers populations of several different microorganisms subjected to four apparently different stresses: aerosolization, freeze-drying, freeze-thawing, and thermal inactivation (in the absence of shear stress, toxic gas effects, or radiation effects) (6-14, 19, 20, 22, 23, 25, 26).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Inactivation kinetics of some microorganisms subjected to a variety of stresses

Cox¹

1976

Appl Environ Microbiol

View full text Add to dashboard Cite

Loss of viability in aerosols of Escherichia coli B, E. coli commune, E. coli Jepp (in nitrogen atmospheres), and Semliki forest virus (in air) was determined as a function of relative humidity at 26.5 C. The decay patterns could be accounted for accurately by means of an equation derived from a postulated mechanism involving population distributions and first-order denaturation kinetics. Analyses of published curves describing loss of viability (all of which were semiexponential, ie., J-shaped) for various microorganisms stressed by different techniques showed that the proposed mechanism also provided an explanation for effects of the following factors (in the absence of open air, oxygen, or radiation): (i) influence of relative humidity upon aerosol survival; (ii) dissemination of aerosols from the wet and dry states; (iii) protecting additives; (iv) relative humidity change before reconstitution; (v) reconstituting fluids; (vi) water content of freeze-dried product; (vii) storage gas; and (viii) storage temperature. The data indicate that low temperatures and high pressures were likely to be conducive to the preservation of viable bacteria and viruses, provided that cold shock and decompression shock were absent.

show abstract

“…The results presented in Fig. 1 through 4 and were analyzed by a curve-fitting procedure as n of described before (15), but in terms of equation 9 . at (see Appendix):…”

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Inactivation kinetics of some microorganisms subjected to a variety of stresses

Cox¹

1976

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…The reation rate with each site is of a first order, but the observed overall rate is the sum of all the separate rates and is changing with exposure time. Cox et al (1973) tried to fit a mathematical expression for oxygen-induced death in dehydrated bacteria (freeze-dried and aerosolized). They suggested survival equations based on reaction rates of oxygen, first with a carrier molecule-X, and then with the sensitive substance-A.…”

Section: Pseudomonas Syringaementioning

confidence: 99%

Survival and enumeration of aerosolized and freeze-dried genetically engineeredE. coli, under controlled environmental conditions

Israeli

Shaffer²,

Lighthart

1994

Aerobiologia

View full text Add to dashboard Cite

“…Cox and Heckly (12) and Cox et al (10) found that the toxic action of oxygen upon freeze-dried Serratia marcescens 8UK followed first-order kinetics at low concentrations of oxygen (i.e. logarithm of the viability at a given storage time was directly proportional to oxygen concentration) and zero order at high oxygen concentration (i.e.…”

Section: Introductionmentioning

confidence: 98%

Aerosol survival of Serratia marcescens as a function of oxygen concentration, relative humidity, and time

Cox¹,

Gagen²,

Baxter³

1974

Can. J. Microbiol.

Self Cite

View full text Add to dashboard Cite

1974. Aerosol survival of Serratia tnarcescens as a function of oxygen concentration, relative humidity, and time. Can. J. Microbiol. 20: 1529-1534 Previously the kinetics of loss of viability of freeze-dried Serratia r?~arcesce7u 8UK were determined by Cox and Heckly as a function of oxygen concentration and time. Results are presented here when dehydration is brought about by aerosolization into atmospheres of low relative humidity (RH) rather than by freeze-drying. As for freeze-dried S . marcescens, oxygen was toxic and viable decay followed the same kinetics with respect to oxygen concentration and time. The influence of R H upon viable decay (which was not studied in the previous report) was that above 65% R H oxygen was not toxic but was progressively more toxic as the humidity was further reduced. Kinetic analyses of the results indicate that the site for the toxic action of oxygen lies in the interspace between the cytoplasmic membrane and the cell wall. Such a finding is consistent with other data which suggest that cell division and (or) cell wall synthesis in bacteria are inhibited by oxygen.Cox, C. S., S. J. GAGEN et J. BAXTER. 1974. Aerosol survival of Serratia marcescens as a function of oxygen concentration, relative humidity, and time. Can. J. Microbiol. 20: 1529-1534. Cox et Heckly anterieurement ont determine la cinetique de la perte de viabilitt de cellules IyophilisCes de Serratia marcescens 8UK en fonction de la concentration d'oxygene et du temps. Nous presentons ici des resultats o i~ la dkshydratation est amenCe par l'atrosolisation dans des atmospheres de faible humidit6 relative au lieu que par lyophilisation. Comme pour les cellules lyophilistes de S. marcescens, l'oxygene est toxique et le decroissement de la viabilite suit la m&me cinetique en regard de la concentration d'oxygene et du temps. L'influence de l'humidite relative sur la viabilite (laquelle n'a pas CtC determinee prCcCdemment) est que en haut de 65% de R H l'oxygene n'est pas toxique mais le devient progressivement lorsque I'humiditC est rCduite. Les analyses cinetiques des resultats indiquent que le site de l'action toxique de l'oxygene reside dans l'espace entre la membrane cytoplasmique et la paroi cellulaire. Cette conclusion est en accord avec d'autres donntes qui suggerent que la division cellulaire et (ou) la synthese de la paroi cellulaire chez les bactkries est inhibee par I'oxygene.[Traduit par le jouri~al]

show abstract

A Mathematical Expression for Oxygen-induced Death in Dehydrated Bacteria

Cited by 14 publications

References 17 publications

Inactivation kinetics of some microorganisms subjected to a variety of stresses

Inactivation kinetics of some microorganisms subjected to a variety of stresses

Survival and enumeration of aerosolized and freeze-dried genetically engineeredE. coli, under controlled environmental conditions

Aerosol survival of Serratia marcescens as a function of oxygen concentration, relative humidity, and time

Contact Info

Product

Resources

About