The Effect of X-Ray Upon Bacteriophage and Upon the Bacterial Organism

Abstract

285menbs were made of energy reflected by the epithelium inside the cheek, it may still be assumed that about one-third of the energy entering the cheek passed through.These studies indicate that living tissue is generally impermeable to all but a narrow b a d of ordinary radiant energy lying between wave lengths of 0.6 to 1.6 micron. Maximum penetration seems to occur at a wave length of 1.15 micron. What physiological or therapeutic effects such radiant energy has is still largely undetermined. A lamp specially designed to deliver rays in the range indicated has been ma!d$e and is available for study.A number of workers recently have demonstrated that it is possible to produce variants among both plants and animals by exposure to ithe effect of X-rays We, in turn!, have endeavored to demonstrate change by a similar procedure applied to the Bacteriophage and to the organism susceptible to the Bacteriophage, following suggestions made by Dr. Olson.Seven strains of B. coli bacteriophage were seleclted and for each of these wecultured the particular strain of B. coli acted upon by its respective strain of bacteriophage. There were selected 7 coli bacteriophages and 6 strains of B. coli for $this series of experiments.These bacteriophages were effective as foliows upon the bacterial strains: one for all the strains, one for 5, one for 2 and 3 could lyse only one strain each of the organisms. There were thus 42 combinations possible in such a set up of tubes in case m y variation were to appear.The organisms were young cultures in the phase of positive logarithmic growth in beef infusion broth and the phages were recent filtrates in the same medium. These were contained within lead free glass test tubes. Exposure to X-ray was carried out at a dlistance of approximately fourteen inches from the target of a Roentgen tube actuated by approximately 75,000 volts of electricity. The exposure period was 30 minutes. Following this treatment each bacterio-The following methods for exposure were followed.at PENNSYLVANIA STATE UNIV on June 25, 2015 ebm.sagepub.com Downloaded from

The Effect of “Low Voltage” X-rays on the Electrophoretic Migration Velocity, Viability and pH ofEscherichia coliSuspensions

“…It would appear that x-rays either interfere with the growth and normal development of bacteria and yeasts, or produce a decided lethal effect according to many of the recent reports among which are those by Lacassagne (1928), Holweck (1929), Clark and Boruff (1929), Pauli and Sulger (1929), Holweck and Lacassagne (1930), Ellinger and Gruhn (1930), Wyckoff (1930a and1930b) and others. However, Beckwith, et al (1930) reported that the bacteria were not killed in their experiments. Curie (1929) and Glocker (1931) have discussed the bactericidal action of x-rays from the quantum standpoint.…”

The Effect of Soft X-ray Irradiation on Bacteriophages

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Although much work has been done on the effects of X-rays on bacteria and other biologic materials, relatively little has been done on bacteriophages. Among the results reported is that of Beckwith, Olson and Rose (1930) who worked with six strains of Escherichia coli and seven Escherichia coli bacteriophages. They found that exposures to rays from a Roentgen tube for 30 minutes reduced, but did not destroy the lytic activity of 3 of the possible 42 combinations.

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