Showing papers in "Journal of Bacteriology in 1946"
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TL;DR: It was thought possible, however, that if a medium were devised which eliminated the necessity of an organism's utilizing ammonia as a sole source of nitrogen, other organisms of the fecal group could be detected which would hydrolyze urea.
Abstract: Bacterial decomposition of urea has been especially useful in distinguishing between members of the Proteus group and other fecal organisms encountered in stool examinations. Originally, the reactions of these organisms on urea were determined by the use of sterile urine as a culture medium, and only recently have media of known composition been employed (Rustigian and Stuart, 1941). Of the media of known composition, those of Rustigian and Stuart and of Ferguson and Hook (1943) have been found suitable to differentiate between Proteus and other organisms believed to be urease-negative. In considering the formulae of the two media mentioned, it is obvious that the medium of Ferguson and Hook (urea, 2 per cent; phosphate buffer; NaCl, 0.5 per cent; and ethyl alcohol, 1.0 per cent) is of such a nature that only an organism capable of utilizing urea as a sole source of nitrogen would grow. The possibility therefore arises that this medium would not detect organisms which could hydrolyze urea but which could not utilize the liberated ammonia as a source of nitrogen. In such a case, no growth would occur, and the organism would be considered urease-negative. The medium of Rustigian and Stuart (urea, 2 per cent; yeast extract, 0.01 per cent; and phosphate buffer), because of the extremely small amount of nutritive material present, also is subject to the same theoretical limitations, particularly in view of the fact that an organism incapable of utilizing ammonia is probably forced to use the yeast extract not only as a nitrogen source but also as a carbon source. If these materials are exhausted before the organism shows appreciable growth, its ability to hydrolyze urea cannot be adequately determined. The high buffer capacity of the medium would also mask slight urease activity if such an organism were capable of initial growth in the medium. These two media, however, as stated by the authors, were designed for the detection of Proteus organisms, and for this purpose they are well suited. It was thought possible, however, that if a medium were devised which eliminated the necessity of an organism's utilizing ammonia as a sole source of nitrogen, other organisms of the fecal group could be detected which would hydrolyze urea.
711 citations
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TL;DR: The ability of some groups of closely related yeasts to use potassium nitrate as a source of nitrogen was applied successfully by Stelling-Dekker (1931) and later, Lodder added other nitrogen compounds, namely, ammonium sulfate, urea, asparagine, and peptone, in diagnostic tests for her classification of the nonsporogenous, nonfilamentous yeasts.
Abstract: The ability of some groups of closely related yeasts to use potassium nitrate as a source of nitrogen was applied successfully by Stelling-Dekker (1931) to the classification of the sporogenous yeasts. Later, Lodder (1934) added other nitrogen compounds, namely, ammonium sulfate, urea, asparagine, and peptone, in diagnostic tests for her classification of the nonsporogenous, nonfilamentous yeasts. She employed a modification of Beijerinck's (1889) auxanographic technique in the following manner: About 2 ml of a dense suspension of the yeast to be tested were placed in a petri dish. It was assumed on the basis of Wildiers' (1901) work that the use of such a heavy inoculation of cells would provide adequate growth factors. An agar medium consisting of 2 per cent glucose, 0.1 per cent potassium dihydrogen phosphate, 0.05 per cent magnesium sulfate, and 2.0 per cent washed agar was cooled to 40 C and poured into the dish. The medium and yeast were quickly mixed. After the medium had solidified, the plate was placed in an incubator to dry for a few hours at 30 C. Then small portions of the nitrogen-containing compounds were placed on the solid surface of the inoculated agar. On incubation at 25 C, an area of growth was produced around those compounds that were assimilated. Lodder's study disclosed that a majority of the yeasts with which she worked were capable of utilizing all the compounds that she had introduced. However, some species of Torulopsis and all species of Kloeckera failed to assimilate ammonium sulfate, urea, and asparagine. These facts were subsequently incorporated in her descriptions of species and genera. These nitrogen compounds, as well as the use of the auxanographic plate method, were generally adopted for diagnostic purposes by succeeding workers in Europe and South America. Langeron and Guerra (1938) used Lodder's medium and technique for their study of filamentous yeasts belonging to the genus Candida. Because they found that urea diffused through the medium so rapidly that it sometimes overlapped the diffusion zones of other nitrogen sources, only one other test substance was placed in the same plate. Langeron and Guerra found that 2 of their 16 species of Candida, C. pelliculosa and C. zeylanoides, utilized peptone only, but 6 assimilated urea. At variance with these results were the findings of Diddens and Lodder (1942) with respect to the assimilation reactions of the Candida species. They found that C. pelliculosa and C. zeylanoides utilized ammonium sulfate, urea, and asparagine in addition to peptone, and that the species C. tropicalis, C. guil-
469 citations
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TL;DR: Following Hartman, who first suggested the use of Sudan black B, in place of red Sudans, as a bacterial fat stain, Burdon, Stokes, and Kimbrough confirmed the greater value of this dye and modified the procedure, resulting in the much superior procedure to be described here.
Abstract: Following Hartman, who first suggested the use of Sudan black B, in place of red Sudans, as a bacterial fat stain (Hartman, 1940), Burdon, Stokes, and Kimbrough (1942a) confirmed the greater value of this dye and modified the procedure for demonstrating intracellular fatty material in bacteria by preparing, from suspensions of the organisms in alcoholic Sudan black B solution, dried films counterstained with safranine. Previously it had been thought that dried, fixed films were entirely unsuitable for fat stains (Lewis, 1941). These permanent films were regarded as an obvious improvement over the wet preparations used by earlier workers, and they were shown to be of practical aid in the classification of aerobic sporeforming bacilli (Burdon, Stokes, and Kimbrough, 1942b), but the staining method still had a number of undesirable features. Further experimentation has resulted in the development of the much superior procedure to be described here. The new method is not only simpler, requiring no more effort than a gram stain, but it is also far more rewarding, for the films now reveal clearly intracellular lipid matter that previously has not been seen or even suspected. The improved stain has increased differential value. More. over, its application, to various bacteria has resulted in certain general findings of unusual interest.
293 citations
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TL;DR: The phytochemical properties ofSaccharomyces cerevisiae, a type of baker's yeast, and its application in food spoilage and wound healing are revealed.
Abstract: Saccharomyces cerevisiae ATCC 918................ 2,500,000 <1,000 Cryptococcus neoforman ............... ............ 1,300,000 <1,000 Rhodotorula ep. ................................... 1,300,000 1,000 Hormodendrum pedrosoi 275........................ 20,000 <1,000 Monosporium apiospermum........................ 20,000 <1,000 Phialophora verrucosa............................. 20,000 <1,000 Blastomyces dermatitidis 930....................... <10,000 <1,000 Candidd albicans.................................. <10,000 ' <1,000 Coccidioides immitis 819........................... <10,000 <1,000 Epidermophyton floccosum......................... <10,000 <1,000 Geotrichum sp..................................... <10,000 <1,000 Hormodendrum compactum ......................... < 10,000 <1,000 Nocardia asteroides653.<10,000 <1,000 Sporotrichum schenkii ................ ............. < 10,000 <1,000 Trichophyton rubrum ............... ............... < 10,000 <1,000 Bacillus subtilis .................................... <10,000 28,000,000 Staphylococcus aureus FDA 209.................... <10,000 21,000,000 Escherichia coli .................................... <10,000 3,500,000 Pseudomonas aeruginosa ATCC 9027............... <10,000 350,000
109 citations
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TL;DR: A comparative study of a series of isolates and the available authentic cultures of C. acnes is made in an attempt to clarify their taxonomic position.
Abstract: The organism known as the \"acne bacillus\" in medical literature was first observed by Unna (1896) in histological sections of acne comedones, but Sabouraud (1897) was the first to cultivate this organism successfully in pure culture from the contents of acne pustules. Subsequent studies on the etiology of acne vulgaris by Gilchrist (1900, 1903), Hall6 and Civatte (1907), Hartwell and Streeter (1909), Fleming (1909), Suldmerson and Thompson (1909), and Molesworth (1910) indicated that the acne bacilli were morphologically similar to the corynebacteria but differed markedly from these organisms in showing a strong preference for anaerobic conditions. Gilchrist (1900) named the organism Bacillus acnes, whereas Bergey et al. (1923) placed it in the genus Corynebacterium because of its morphological relationship to the members of this group. Our interest in these organisms became aroused following the observation of Weiser and Gunter (1942) of this laboratory that samples of human blood plasma destined for a civilian plasma bank contained anaerobic diphtheroids as one of the principal contaminants. These workers were able to show that such organisms occurred on normal skin and probably gained entry into the blood plasma as the result of ineffective skin disinfection preceding venipuncture. The anaerobic diphtheroids isolated from plasma and skin seemed to fit the general description of Corynebacterium acnes (Bergey et al., 1939), but, as the inclusion of such organisms in the genus Corynebacterium seemed questionable to us, we considered it worth while to make a comparative study of a series of isolates and the available authentic cultures of C. acnes in an attempt to clarify their taxonomic position. It also seemed desirable to obtain quantitative data on the occurrence of these organisms on normal human skin.
106 citations
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TL;DR: Attention was focused on lipid production by yeasts and related organisms through the results of Lindner and associates, who developed a process for the production of fat from carbohydrates by Endomyces vernalis in Germany during World War I.
Abstract: It has been well established that fatty substances are produced by various microorganisms, notably by certain yeasts and filamentous fungi as well as by the tubercle bacilli and a species of Azotobacter. The tubercle bacilli and other acid-fast bacteria contain from 20 to 40 per cent lipid on the dry-weight basis (Anderson, 1939). Even some of the common non-acid-fast bacteria may contain considerable amounts of lipid. Escherichia coli, Staphylococcus albus, and Bacillus megatherium were found to contain from 8 to 40 per cent lipid when grown on certain media (Larson and Larson, 1922). More commonly, however, the lipid content of bacteria has been reported to be below 10 per cent. The results of Gorbach and Sablatnog (1934a, 1934b) may be cited in this connection. They found that whereas the lipid content of Pseudomonas aeruginosa was 0.6 per cent when grown on meat extract agar at pH 7.0, there was as much as 3.9 per cent lipid when the organism was cultivated on mannitol. Anderson (1939) reported 2 to 6 per cent lipid in cells of Phytpmonas tumefaciens and 7 per cent in Lactobacillus acidophilus. Among the bacteria, Azotobacter indicum is unique in lipid production (Starkey and De, 1939). The cells of this bacterium commonly contain two large fat globules, one at each end of the rod-shaped cells, and as much as 50 per cent of the cell volume is occupied by the fat globules. The lipid content of filamentous fungi ranges between 1 and 40 per cent, and differs with the various cultures and the conditions under which they are grown. (Pruess, Eichinger, and Peterson, 1934; Prescott and Dunn, 1940; Bloor, 1943). The lipid content of 24 filamentous fungi studied by Pruess and Strong (1933) was from 1 to 25 per cent with an average between 6 and 9 per cent. Ward, Lockwood, May, and Herrick (1935) determined the lipid content of 61 fungi and reported that six of the fungi contained over 20 per cent lipid. Under favorable conditions of cultivation, Penicillium javanicum was found to contain as much as 41.5 per cent. Large amounts of lipid were produced by species of Oospora Wallroth when grown on milk, and the results of Geffers (1937) indicate that this organism can be used to synthesize fat from milk wastes. Up to 50 per cent of the mycelium could be extracted with fat solvents. Attention was focused on lipid production by yeasts and related organisms through the results of Lindner and associates, who developed a process for the production of fat from carbohydrates by Endomyces vernalis in Germany during World War I (Fink, Haehn, and Hoerburger, 1937; Prescott and Dunn, 1940). When cultivated under conditions favorable for lipid production, this yeast con-
93 citations
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TL;DR: The physiological characteristics of Streptococcus s.b.e. have been described, which were recovered from approximately one-third of the patients afflicted with bacterial endocarditis, has several unique physiological characteristics which afford a relatively simple and accurate means for identification.
Abstract: In two preliminary publications (Loewe, Plummer, Niven, and Sherman, 1946; Niven and White, 1946) a report has been presented outlining the identities of various streptococcus cultures isolated from a large number of cases of subacute bacterial endocarditis. One of the largest groups recorded appeared to represent a hitherto unrecognized variety, or species. This streptococcus, which was recovered from approximately one-third of the patients afflicted with bacterial endocarditis, has several unique physiological characteristics which afford a relatively simple and accurate means for identification. Furthermore, all the strains which have been studied thus far have fallen into one of two serological types. For the sake of convenience this streptococcus is referred to as \"Streptococcus s.b.e.\" The successful use of penicillin-anticoagulant therapy for subacute bacterial endocarditis by Loewe (1945a, 1945b) has recently received wide attention. For the first time a large proportion of the patients suffering from this disease are being cured. As reported by Loewe, a majority of the cases which do not respond to the treatment are ones from which Streptococcus s.b.e. have been recovered. The purpose of the present publication is to describe in detail the physiological characteristics of Streptococcus s.b.e.
88 citations
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83 citations
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TL;DR: This paper will report on a few of more than five hundred experiments which have led to an increase in the yield of penicillin from the range of 2 to 6 Oxford units per ml to as much as 160 to 220 Oxford Units per ml.
Abstract: The production of penicillin by the surface culture of Penicillium notatum is the foundation upon which a large new industry has been built. Although cultivation of the mold in submerged culture now appears to be more economical and more practical from an industrial standpoint, surface cultures were utilized to produce the penicillin that first effected the remarkable clinical cures which indicated that the large investment of time and money made during the past three years would be justified. Previous investigators of penicillin production have not been successful in developing a highly productive medium. Fleming (1929), the discoverer of the drug, refers only to the use of a \"nutrient broth,\" whereas Clutterbuck, Lovell, and Raistrick (1932) used a modified Czapek-Dox medium. Although the yields of penicillin obtained by this group and by Fleming were not evaluated in terms of the Oxford unit adopted later, they were undoubtedly very low, at least when compared with present standards. Abraham et al. (1941), using the same modified Czapek-Dox medium with the addition of small amounts of a crude yeast extract, obtained only 2 to 6 Oxford units per ml. This paper will report on a few of more than five hundred experiments which have led to an increase in the yield of penicillin from the range of 2 to 6 Oxford units per ml to as much as 160 to 220 Oxford units per ml. This increase in yield has been achieved primarily by the proper selection of organisms and nutrients, including the use of corn steep liquor, the use of lactose as the principal carbohydrate, and the addition of nutrients during the course of the fermentation.3
82 citations
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81 citations
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TL;DR: It has been concluded that the substance acts only on dividing cells, leaving nondividing cells unaffected, and how long the influence of penicillin on bacteria might last after its complete removal from the culture medium is determined.
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TL;DR: Experimental work was begun in order to prove the hypothesis of inhibition of N. gonorrhoeae by agar, or a substance in it, that was proposed by Gould, Kane, and Mueller.
Abstract: The separation of an inhibitor for Neisseria gonorrhoeae from commercial agars was attempted on the basis of previous work by Mueller and Hinton (1941) and Gould, Kane, and Mueller (1944). In addition, this inhibitor was compared with certain organic compounds of a similar nature by biologic tests of inhibitory activity. Until the medium of Mueller and Hinton (1941) was developed, it was thought impossible to grow N. gonorrhoeae on a simple, well-defined medium, but these investigators showed that casein hydrolyzate, meat extract, agar, and starch supported growth of the organisms as well as chocolate blood agar or ascitic fluid agar. Gould, Kane, and Mueller (1944) further showed that a fluid medium containing casein hydrolyzate, sodium chloride, magnesium sulfate, and phosphate buffer would support growth of N. gonorrhoeae, and that a similar medium with agar added would fail to grow the organisms. The addition of starch to this last medium again permitted growth, which led the authors to the hypothesis that starch neutralized an inhibitor present in the agar. Frantz (1942) also developed a similar simple fluid medium for a closely related organism, Neisseria intracellularis, and observed inhibition of growth of the organisms upon addition of agar to the medium. The experimental work which follows was begun in order to prove the hypothesis of inhibition of N. gonorrhoeae by agar, or a substance in it, that was proposed by Gould, Kane, and Mueller.
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TL;DR: This study was undertaken to determine conditions which would result in a high percentage of survival during dehydration and storage of an organism that is easily killed by drying.
Abstract: The preservation and storage of nonsporeforming bacteria have long been problems in the laboratory and in industry. Storage of liquid cultures for long periods of time has been found unsatisfactory with most species. Cultures dried under carefully controlled conditions have remained viable over long storage periods, but the percentage of surviving cells has usually been very low. This study was undertaken to determine conditions which would result in a high percentage of survival during dehydration and storage of an organism that is easily killed by drying. A search of the literature revealed very few references to quantitative data on the survival of dried vegetative bacteria. The review by Rahn (1945) refers to some work in which quantitative data were obtained, but survivals were very low in most instances. Rogers (1914) showed that powders of high viable cell count could be produced by spray-drying milk cultures of lactic streptococci or by drying such cultures from the frozen state under vacuum. On the assumption that the milk cultures contained one billion cells per ml, from a calculation of Rogers' results with Streptococcus lactis, giving consideration to the solids content of the skimmed milk, it would appear that he obtained survivals approaching 100 per cent in several samples of powder in which viable counts of over 10 billion per gram were observed. Rogers' experiments on the drying of cultures of Lactobacilus bulgaricUm and the legume bacteria indicated that survivals of about 10 per cent were obtained with these nonsporeforming rods. Rogers also found that powders containing up to 1.39 per cent moisture stored satisfactorily at 17 C but not at 30 C. Higher survivals were observed in powders stored under vacuum than in those stored in air, oxygen, nitrogen, hydrogen, or carbon dioxide for a period of 4 months. Differences in resistance todrying among various species of nonsporing bacteria were found by Stark and Herrington (1931). Streptococcus lactis and Streptococcus paracitrovorous were found to be more resistant than yeast and staphylococci, which were in turn more resistant than Escherichia coli and LactobaciUus acidophilus. Exposure of the dried cultures to oxygen resulted in a rapid loss of viability in all cases. The work of Miller and Schad (1943) emphasizes the importance of protecting dried bacteria from sunlight. It was found that meningococci dried on various surfaces were rapidly killed by direct sunlight, and even diffuse sunlight passing
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TL;DR: In the study of the production of antibiotics by microorganisms, especially when a given substance receives recognition as a chemotherapeutic agent, it becomes necessary, in order to maintain the potency of the culture cr to obtain more active cultures, to isolate fresh strains of the organism producing the particular antibiotic.
Abstract: In the study of the production of antibiotics by microorganisms, especially when a given substance receives recognition as a chemotherapeutic agent, it becomes necessary, in order to maintain the potency of the culture cr to obtain more active cultures, to isolate fresh strains of the organism producing the particular antibiotic. This can usually be accomplished by two procedures: (1) Fresh cultures of the organism are isolated indiscriminately from various natural substrates, such as soils and composts, and tested for their potency. (2) New strains are obtained by plating the original culture and then isolating individual colonies. Before plating, the culture may be pretreated, as by exposure to different radiations, in order to kill a large number of sensitive spores. Both of these methods have been utilized wwith considerable success in the isolation of more potent strains of penicillin-producing fungi. Comparatively little progress has been mnade, however, in the case of streptomycinproducing strains of Streptomyces grisnus. It has been established that penicillin production is characteristic of the Penicillium notatum and Penicillium chrysogenum groups; the variation in potency of different strains is either quantitative or qualitative, according to the type of penicillin produced. The production of streptomycin, however, is characteristic of only a certain few strains of S. griseus (Waksman, Schatz, and Reynolds, 1946). This organism represents a distinctly heterogeneous group, especially in regard to the production of antibiotics. In a recent examination of 40 freshly isolated cultures of S. griseus, none was found to produce the typical streptomycin; only one of these cultures was found to form an interesting antibiotic. This antibiotic was active against certain gram-positive and gramnegative bacteria, in a manner comparable to streptothricin and streptomycin, but it was both chemically and biologically distinct from either of these two substances. These results pointed to the difficulty of obtaining fresh streptomycin-producing cultures from natural substrates. Numerous attempts to isolate streptomycin-producing strains of S. griseus from natural substrates have so far yielded, in addition to the two original strains obtained in this laboratory in 1943, namely, D-1 and 18-16 (Schatz, Bugie, and Waksman, 1944), only two cultures. One isolation was made in another laboratory, and the
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TL;DR: The purpose of the present study was to determine the effect of various controlled changes in the environment, such as nutrition, hydrogen ion concentration, temperature, and type of inoculum on the two morphological forms of Blastomyces dermatitidis.
Abstract: Blastomyces dermatitidis possesses two morphological forms, a yeastlike form in tissue and a mycelial form on Saboraud's medium at room temperature. A yeastlike form similar to the form appearing in tissue may be obtained if the organism is grown on blood agar at 37 C. An extensive literature has developed around blastomycosis as a clinical entity, but only a small proportion of the papers have been concerned with the biological nature of the etiological agent, Blastomyces dermatitidis. Ricketts (1901) described the two morphological forms. Hamburger (1907) concluded that temperature was the most important factor influencing morphology, and that room temperature favored mycelial formation, but incubator temperatures favored the yeastlike form. He did not determine the effect of intermediate temperature or of hydrogen ion concentration. Michelson (1928) studied the effect of higher temperatures and noted that temperatures of 37, 41, and 45 C favored the growth of the yeastlike form. Moore (1933) studied the organism for the purpose of determining its position in botanical classification. He studied its growth in media of different hydrogen ion concentrations, but each hydrogen ion concentration was represented by a different medium. The purpose of the present study was to determine the effect of various controlled changes in the environment, such as nutrition, hydrogen ion concentration, temperature, and type of inoculum on the two morphological forms of Blastomyces dermatitidis.
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TL;DR: This work will report on the development of streptomycin resistance in 12 strains of the shigellae and the nature of this in vitro resistance.
Abstract: Recent reports have clearly shown that bacteria tend to become rapidly resistant to streptomycin, both in vitro and clinically (Buggs, Bronstein, Hirshfeld, and Pilling, 1946; Miller and Bohnhoff, 1946; Youmans and Feldman, 1946). In the present work we will report on the development of streptomycin resistance in 12 strains of the shigellae and the nature of this in vitro resistance. A brief summary of this work has previously been reported (Klein and Kimmelman, 1946).
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TL;DR: The nutritional requirements of the tumor-inducing phytopathogenic bacteria and soil saprophytes which Conn (1942) has placed in the genus Agrobacterium have received somewhat more attention than have the requirements of most of the other groups of plant-disease bacteria.
Abstract: The nutritional requirements of the tumor-inducing phytopathogenic bacteria and soil saprophytes which Conn (1942) has placed in the genus Agrobacterium have received somewhat more attention than have the requirements of most of the other groups of plant-disease bacteria. It is clear from the literature (Sagen, Riker, and Baldwin, 1934; Riker, Lyneis, and Locke, 1941; Hofer, 1941) that the crown-gall bacterium, Agrobacterium tumefaciens, and the common soil saprophyte, Agrobacterium radiobacter, grow well in solutions containing only ammonium or nitrate nitrogen and any of a number of carbon sources. On the other hand, the remaining two species at present in this genus, the hairy-root organism, Agrobacterium rhizogenes, and the cane-gall bacterium, Agrobacterium rubi, are reported to have somewhat more complex nutritive requirements. For example, Sagen, Riker, and Baldwin (1934) summarize their study of A. rhizogenes by stating that it "seems to lack the ability of P. tumefaciens and B. radiobacter to utilize the simpler nitrogenous compounds." Similar observations are recorded for A. rubi by Pinckard (1935) and Hildebrand (1940). Inasmuch as knowledge of the exact nutrition of this group may be useful in interpretations of the systematics and general physiology of the genus, as well as provide source material for eventual evaluation on the possible interrelationship of microbial nutrition and virulence (McNew, 1938; Van Lanen, Baldwin, and Biker, 1940), a study of the four Agrobacterium species was undertaken. At the same time some observations were made on the nutritive requirements of Bacterium pseudotsWae and Agrobacterium gypsophilae, two species which have been placed in an Appendix to Agrobacterium in the forthcoming sixth edition of Bergey's Manual of Determinative Bacteriology. In general, the objective was prompt, moderate growth in simple solutions of known composition, rather than development as rapid and luxuriant as possible in complex media.
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TL;DR: During an investigation' of cellulose decomposition by termites, anaerobic shake tubes containing cellulose, proteose-peptone, and agar were inoculated with serial dilutions of the crushed alimentary tract of a termite from a laboratory colony, suggesting that the causal organism was an actinomycete.
Abstract: During an investigation' of cellulose decomposition by termites, anaerobic shake tubes containing cellulose, proteose-peptone, and agar were inoculated vith serial dilutions of the crushed alimentary tract of a w-orker termite (Amitecmes minimus) from a laboratory colony. Several large clear spots which appeared in the cellulose after several weeks wN-ere found to contain numerous minute branching filaments, suggesting that the causal organism wNas an actinomycete. Since it appeared to differ from other celltulose-decomposing actinomycetes, some additional experiments were performed. It was isolated in pure culture by inoculating it into shake tubes of cellulose or glucose with serial dilution and by subculturing similar series from a colony in the tube of highest dilution. A sparse formation of spores wAas observed in cuiltures grown on cellulose and proteose-peptone, but, if powdered dried grass or its aqueous extract was used in place of the proteose-peptone, an abundance of spherical spores developed. Their diameter averaged about 0.8,. They were borne singly on short side branches of the mycelium (figure 1) in a manner characteristic of the genus Micromonospora.2 The oxygen relationships of this strain of Micromonospora wN-ere studied by inoculating parallel series of aerobic and anaerobic dilution tubes containing cellulose, agar, and grass extract. In the anaerobic series all air was displaced by bubbling oxygen-free nitrogen (95 per cent) and carbon dioxide (5 per cent) through the test tube before stoppering. In the aerobic series alveolar air (approximately 15 per cent 02, 5 per cent CO2, and 80 per cent N2) was similarly bubbled. The tubes were then stoppered with a sterile rubber stopper, inverted several times, and quickly cooled in cold Awater to solidify the agar. This left a thin film of the agar medium lining the wall in the upper, gas-filled half of the tube. After two Neeks of incubation cellulose digestion was evident in all parts of the anaerobic tubes, including the thin layer of cellulose agar in the upper half. In the aerobic series no colonies appeared in this thin agar layer exposed to the gas, nor were any colonies present in the upper 3 cm of solid agar in the lower part of the tubes. Colonies
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TL;DR: This paper deals with the selection of a strain of P. notatum Westling suitable for the production of penicillin in submerged culture, and with investigations of nutrient media and culture conditions as nearly optimal as possible for this procedure.
Abstract: Penicillin was first produced by cultivation of the fungus Penicillium notatum Westling on the surface of a liquid nutrient, such as Czapek-Dox glucose medium. Such a method of cultivation is very laborious, costly, and time-consuming when practiced on a large scale. Huge numbers of bottles or pans must be washed and sterilized, relatively small volumes of nutrient media must be dispensed into individual containers, and each container with its allotment of medium must be sterilized and inoculated. The incubation period for such cultures is usually 6 to 12 days, and, at the conclusion of the fermentation, considerable hand labor is required to remove the penicillin-containing liquors from the numerous fermentation vessels and from the fungus mycelium. It was obvious that a more economical fermentation process would result from growing the mold submerged and uniformly distributed in vats or tanks such as are used in other fermentation industries. Submerged mold fermentation processes have been previously used for the production of gallic acid (Calmette, 1902), gluconic acid (Moyer et at., 1940), and lactic acid (Ward et al., 1938), and the adaptation of this method to the cultivation of P. notatum appeared to offer a means of decreasing the labor involved, of decreasing the fermentation time, and of increasing the penicillin yield. This paper deals with the selection of a strain of P. notatum Westling suitable for the production of penicillin in submerged culture, and with investigations of nutrient media and culture conditions as nearly optimal as possible for this procedure.3 (P. notatum NRRL 832 was originally selected and evaluated for submerged penicillin production by the senior author.)
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TL;DR: Some of the antibiotic properties of what is believed to be a new antibiotic agent from a plant source, which occurs in the tomato plant and has been designated "tomatin," are described.
Abstract: The clinical attractiveness of antibiotic agents, as typified by penicillin and streptomycin, lies in their ability to effect striking and specific bacteriostatic action in vivo without the simultaneous production of severe toxic symptoms. However, since penicillin and streptomycin are limited in their usefulness because of their ineffectiveness against certain important groups of pathogenic organisms, the search for new antibiotic agents continues in the hope that additional substances having sufficiently low toxicity will be found whose high antibiotic activity against the penicillinand streptomycin-resistant organisms will permit their therapeutic use in the conquest of the diseases caused by these pathogens. Although the fungi, including Actinomyces and related forms, and bacteria have been the most fruitful sources of antibiotic agents, antibiotic activity has also been attributed to the juices of certain green plants. Many plant families have been examined for antibiotic activity (Osborn, 1943; Huddleson et al., 1944; Lucas and Lewis, 1944; Seegal and Holden, 1945), and several plant constituents that possess antibiotic activity have been isolated in crystalline form. Among these antibiotic agents are a substance from garlic (Allium sativum) that has been tentatively identified as the sulfoxide of diallyl disulfide (Cavallito, Buck, and Suter, 1945); a substance from common burdock (Arctium minus) that has not been identified but which appears to be a lactone having the empirical formula C15H2006 (Cavallito, Bailey, and Kirchner, 1945); and a substance designated "crepin" from Crepis taraxacifolia that has the empirical formula C14H1604 (Heatley, 1944). It is the purpose of this paper to describe some of the antibiotic properties of what is believed to be a new antibiotic agent from a plant source. This substance occurs in the tomato plant and has been designated "tomatin." Tomatin has not yet been crystallized, but preparations of sufficient potency have been obtained to warrant a preliminary investigation of its antibiotic spectrum. Because of the probable impurity of the tomatin preparation used in the present investigation, the data to be presented have only qualitative or, at best, semi-
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TL;DR: The results indicate that for topical application or for wound cleansing cetyl pyridinium chloride is essentially nontoxic in the concentrations generally used.
Abstract: Cetyl pyridinium chloride is a cationic detergent which is soluble in water, chloroform, alcohol, and acetone. Aqueous solutions are clear, colorless, and odorless. The agent has a depressant action upon surface tension. This property enhances the value of the germicide because irregular surfaces are uniformly wetted. The germicidal properties of cetyl pyridinium chloride were first studied in this laboratory. Shelton et al. (1939, 1940) described the properties of a series of a quaternary ammonium salts and also the effect of the length of the alkyl chain upon germicidal power. Blubaugh et al. (1939, 1940, 1941) briefly described the germicidal activity of cetyl pyridinium chloride. Green and Birkeland (1941) reported studies on the sporicidal activity of this compound. They concluded that the spores of Clostridium perfringens, Clostridium sporogenes, Clostridium tetani, Bacillus anthracis, and Bacillus subtilis were killed under the conditions of the test. These workers reported a curative effect of the compound on artificially infected chick embryos (Green and Birkeland, 1942; Green, 1944). Huyck (1945) demonstrated that a 1:4,000 dilution of cetyl pyridinium chloride was \"bacteriostatic or bactericidal to bacteria found in the oral cavity.\" Huyck (1944) also described the physical and chemical properties of cetyl pyridinium chloride and reviewed the literature on the quaternary ammonium salts. Warren et ai. (1942) found that dilutions of 1:100 or 1:250 produced some reddening of scarified rabbit skin, but that greater dilutions were without harmful action. Subcutaneous injections of a 1:100 dilution in phosphate buffer produced slight edema and reddening at the site of injection, but higher dilutions had no untoward effect. These results indicate that for topical application or for wound cleansing cetyl pyridinium chloride is essentially nontoxic in the concentrations generally used. It is the purpose of this paper to report the germicidal activity of cetyl pyridinium chloride against a variety of organisms, and the effect of temperature, pH, and presence of protein upon the germicide.
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TL;DR: The object of the present work was to study the effects of plant passage and of various cultural environments in inducing variation in a population of Rhizobium known to be homogeneous at the commencement of the tests.
Abstract: Strains of Rhizobium may be distinguished in their behavior in symbiosis by their ability to infect a given host plant, as well as by the types and numbers of nodules produced and by the nodules' effectiveness in benefiting the host through nitrogen fixation. Allen and Baldwin (1931) have reviewed the changes which strains of Rhizobium have been observed to undergo, and the more important of these may be summarized. Nobbe and Hiltner (1893) and Frank (1899) claimed that growth of Rhizobium on gelatin media could induce ineffectivity in nitrogen fixation in the nodules or even complete loss of ability to infect the roots. Other workers have claimed that cultivation on nitrogen-rich media leads to a reduction in effectivity and vice versa, and Simon (1908), Snieszko (1929), and Hutchinson (1924) present evidence that culture in soil restores lost virulence and effectivity. Finally, Wuinschik (1925) and Allen and Baldwin (1931) claimed that repeated plant passage led to changes in the effectivity of strains, although neither Stapp (1929) nor Virtanen (1945) was able to confirm Wulnschik's results. In all these cases it is not clear whether the observed changes were due to the selective action of the treatment on an already heterogeneous population or whether new variants had appeared during the experiments. The gradual changes often observed could thus be attributed either (1) to the selective increase of a small number of cells originally present in the culture, and bearing the newly observed character, (2) to the development of a few variants that subsequently increased differentially, or (3) to a general change occurring throughout the bacterial population. Further, the majority of tests were made as pot experiments, and under these conditions the possibility of contamination cannot be excluded. The object of the present work was to study, with pure culture technique, the effects of plant passage and of various cultural environments in inducing variation in a population of Rhizobium known to be homogeneous at the commencement of the tests.
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TL;DR: Braun (1945), in a preliminary report on factors controlling bacterial dissociation, furnished data demonstrating the existence of inherent differences between clones in regard to dissociation percentages,2 evidence suggestive of undirected, spontaneous hereditary changes in bacteria.
Abstract: Bruela aortus exhibits the phenomenon of dissociation, that is, changes in colony form, culture characteristics, cell morphology, immunological reactions, biochemical reactions, and virulence. Henry (1933) has presented a detailed description of dissociation in the genus Brucella, which usually involves changes from the antigenically active smooth (S) type to intermediate (I), and to antigenically inactive rough (R), brown (Br), and other types. This type of dissociation resembles variations which are common in many bacterial species. Hadley (1927, 1937) has published general reviews of bacterial dissociation and interpreted such changes as due to normal cyclogenic development. Others (e.g., Mayer, 1938; Reed, 1940; Dubos, 1945) have tried to explain the changes which occur during dissociation as being due to spontaneous hereditary changes (mutations), with a subsequent selection of mutants which can best persist in any given environment. Many investigators (e.g., Hinshelwood and Lodge, 1944) have postulated a direct influence of the environment upon such spontaneous changes. Criticism of Hadley's \"ontogenetic\" theory has arisen from experimental work which has demonstrated the lack of linked character variation, such as agglutinative behavior and cell form, -in the change from the S type to the R type (Humphries, 1944). Such criticism is further substantiated by recent work which provided substantial proof for the existence of undirected, spontaneous hereditary changes (mutations) in bacteria (Demerec, 1945; Demerec and Fano, 1945; Anderson, 1944; Luria and Delbruck, 1943; Gray and Tatum, 1944; Roepke, Libby, and Small, 1944; Severens and Tanner, 1945). Whereas the last-mentioned investigators focused their attention mainly on the mutational step per se, another line of approach to the problem of bacterial variation was provided by studies on differences between dissociating populations (clones) started from single cells and maintained under standard conditions. Thus Braun (1945),in a preliminary report on factors controlling bacterial dissociation, furnished data demonstrating the existence of inherent differences between clones in regard to dissociation percentages,2 evidence suggestive
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TL;DR: The present report deals with the production of small colony variants of E. coli with 2-methyl-1 ,4-napthoquinone and is believed worth recording because of the frequency of their appearance, the purity of the phase obtained, and their possible significance in regard to the mechanism of the antibacterial action of this quinone.
Abstract: Small colony variants of several species of bacteria have been described (Hadley, Delves, and Klimek, 1931; Hoffstadt and Youmans, 1932; Koser and Dienst, 1934; Duff, 1937; Haddow, 1938; Kuhn and Stemnberg, 1931). Their recovery has usually been a matter of chance, because of their sporadic occurrence, with one exception: Youmans (1937, 1942) has reported the regular appearance of small colony variants in 17 strains of staphylococci in response to barium chloride. References to small colony variants of Escherichia coli are rare. Hadley, Delves, and Klimek (1931) mention briefly that \"G\" forms similar to \"G\" forms of the Shigella group extensively studied by them were recovered from 2 strains of E. coli; and Kuhn and Steinberg (1931) found small colony variants in 45 strains of E. coli, among other organisms. The present report deals with the production of small colony variants of E. coli with 2-methyl-1 ,4-napthoquinone and is believed worth recording because of the frequency of their appearance, the purity of the phase obtained, and their possible significance in regard to the mechanism of the antibacterial action of this quinone.
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TL;DR: In the present report a unique physiological characteristic of Streptococcus s.b.e. will be described, namely, the ability to synthesize a polysaccharide from sucrose in broth culture.
Abstract: The identity of 113 cultures of streptococci recovered from cases of subacute bacterial endocarditis has been reported recently (Niven and White, 1946). Of this number, 42 seemed to represent a hitherto unrecognized variety, or species, which has been tentatively labeled Streptococcus s.b.e. In contrast with other streptococci associated with endocarditis those cases caused by Streptococcus s.b.e. respond sluggishly, or not at all, to Loewe's penicillin-anticoagulant therapy (Loewe, 1945a, 1945b; Loewe, Plummer, Niven, and Sherman, 1946). Since prompt identification of Streptococcus s.b.e. may be a lifesaving measure, adequate methods for accomplishing this would be desirable. A detailed description of this streptococcus is to be given in a forthcoming publication. In the present report a unique physiological characteristic of Streptococcus s.b.e. will be described, namely, the ability to synthesize a polysaccharide from sucrose in broth culture.