This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Prior, B. A. Articles by Marth, E. H. Search for Related Content PubMed Articles by Prior, B. A. Articles by Marth, E. H. Agricola Articles by Prior, B. A. Articles by Marth, E. H.

 Previous Article  |  Next Article 

Appl Environ Microbiol. 1975 August; 30(2): 178-185
Copyright © 1975 American Society for Microbiology. All Rights Reserved.

Comparative Effects of Anesthetics on the Viability and Integrity of Escherichia coli ML30

Department of Food Science, University of Wisconsin-Madison, Madison, Wisconsin 53706

ABSTRACT

Cells of Escherichia coli ML30 in a mineral salts medium were exposed to dichlorodifluoromethane (f-12), cyclopropane, halothane, or Ethrane at concentrations of 1.25, 0.2, 0.04, and 0.008x saturation for times up to 1,200 min, and at temperatures in the range of 2 to 37 C. When any of these anesthetics were applied for 300 min at 1.25x saturation, a substantial decrease in number of survivors occurred. Halothane was most bactericidal, cyclopropane and Ethrane were moderately bactericidal, and f-12 was least bactericidal. At saturation values of less than 1.0, none of the four anesthetics had an appreciable effect on viability of E. coli. Greatest increases in cell permeability occurred when anesthetics were used at saturation values of 1.25, and permeability changes generally decreased as the concentrations of the chemicals were reduced. In many instances, anesthetics in the vapor state caused significant increases in cell permeability but little or no loss of viability. This indicated that a close relationship did not exist between loss of viability and increased permeability. All four anesthetics caused E. coli to lose substantial and similar amounts of compounds absorbing at 260 nm. Release of compounds absorbing at 260 nm generally increased as the saturation value of a given chemical was increased. Halothane, Ethrane, and cyclopropane but not f-12 caused lysis of E. coli ML30. Considering all results, E. coli ML30 was damaged more by halothane or cyclopropane than by f-12 or Ethrane. When f-12 was applied at a saturation value of 1.25, the bactericidal effect on E. coli was much greater at 37 or 22 C than at 12 or 2 C.

¹ Present address: Department of Microbiology, University of The Orange Free State, Bloemfontein 9300, South Africa.