Note: Missing page 118. / The widespread use of mass roentgenographic surveys in the past decade has led to an increase in the proportion of individuals having few or doubtful clinical signs and symptoms of tuberculosis. It is difficult and often impossible to demonstrate the presence of the tubercle bacillus in the excreta of such individuals by the use of cultural methods in common laboratory use. Since recovery of the tubercle bacillus admits of no further uncertainty in the diagnosis, its detection in doubtful cases has an importance which can scarcely be overestimated.

This problem was undertaken with the purpose of investigating the possibility of rendering visible an otherwise invisible phenomenon which occurs with pathogenic T. pallidum in the presence of syphilitic sera. Cain (1953) described a microscopic agglutination test which agreed rather well with the Treponema Pallidum Immobilization Test of Nelson and Mayer (1949) , and it was felt that there was a possibility this might be moved from the realm of the microscope to that of a macroscopic tube-type agglutination similar to the Widal test.

The object or this work was to determine the bacteriostatic and bactericidal efficiencies, under various conditions of temperature, concentration, and addition or organic matter, or NaOH and NaOCl respectively, which are marketed commercially as lye and “Javex”. Comparisons or disinfectant compounds were and still are necessary not only for the advancement or knowledge, but also as part of our society or tree enterprise. Thus, when Microbiology became a science, methods were established for testing these disinfectants with various organisms. At the beginning, such comparisons, as made by Koch and others, were unsuitable because they did not take into consideration factors that might affect the efficiency of the disinfectants.

This investigation was originally undertaken because it offered a challenge to attempt the solution of a biological connundrum which has existed for more than half a century. As will be seen later, in the review of the literature, T. pallidum has yet to be grown in vitro (with retention of its pathogenicity for experimental animals) and this fact alone would be enough to stimulate an investigation of the fundamental biological properties of this organism. At the same time, the successful in vitro cultivation of T. pallidum would undoubtedly lead to the development of a stable specific antigen and have far reaching effects in syphilis research. [...]

The host and parasite relationship of the tubercle bacillus and tissue cells has been extensively studied since the days of Koch. The ability or virulent tubercle bacilli to penetrate and to multiply intracellularly causing damage to the host cell has not yet been fully explained. Suter (1952) believes that the fate of the infection could be attributed mainly to the inhibition or some vital function or the cell with its consequent destruction. Thus two properties at least may be necessary to enable tubercle bacilli to establish progressive infection.

The period during and subsequent to World War II has witnessed tremendous progress in the field of agricultural chemicals. Many new organic compounds have been developed and are being recommended for the control of weeds, insects and wireworms in the soil, as well as for the control of fungal diseases of plants. The recent widespread use of some of the newly developed, highly chlorinated hydrocarbons as herbicides and soil insecticides has made it desirable to determine what effect they may incur upon the soil microflora, for it is common knowledge that if such chemicals are bactericidal or even inhibitive to any of the important groups of soil microorganisms, then the normal soil processes would be interfered with and inadequate nutrition of crop plants might result.

Every aspect of modern development utilizes large bodies of water for the disposal of wastes. Increasing numbers of rivers, lakes, and streams that were once relatively pure are now being subjected to pollution, as it has become the established (or at least accepted) practice to discharge every kind of waste into water. The underlying principle of such a procedure is based on both dilution, and auto-purification occurring in flowing water. [...]

The purpose of the present investigation was to demonstrate transformation in the genus Rhizobium, using strains of R. meliloti and R. trifolii as the test organisms. The initial work was directed towards an understanding of the metabolism of these organisms and the selection of stable mutants suitable for use in such a study. Five chloramphenicol-resistant strains of R. trifolii were obtained by a "Crystal Violet-tolerance" technique developed during the course of the present research. Suitably resistant strains of R. meliloti could not be isolated. Streptomycin resistance was subsequently selected for among the chloramphenicol-resistant strains.

The fundamental problem in the nutrition of any organism (animal, plant or microbe), according to Porter (1946), is the construction of a medium, or diet, of known composition which will permit optimum growth and reproduction. With bacteria this problem has led to the development of chemically defined or synthetic media, that is, media composed of known purified chemicals. The advantages of protein free synthetic media for biochemical study were appreciated early in the history of bacteriology.

The first isolation of free living nitrogen-fixing bacteria by Winogradsky and Beijerinck stimulated the attempts to assess the importance of non-symbiotic nitrogen fixation in the nitrogen economy of the soil. Most non-symbiotic nitrogen fixation investigations have been concerned with agricultural soils because of their economic importance. Very few studies of nitrogen fixation have been done with woodland soils, of a virgin nature, which might contribute more to our knowledge of soil processes than would those under cultivation.