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Influence of Phenotypic Dissociation in Bacillus subtilis Strain ET-1 on Iturin A Production. Curr Microbiol 2019; 76:1487-1494. [PMID: 31494740 DOI: 10.1007/s00284-019-01764-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 08/26/2019] [Indexed: 10/26/2022]
Abstract
Iturin A is a very important cyclic lipopeptide produced by several B. subtilis strains and has large commercial and therapeutic application potentials but its production on industrial scale has not been realized yet. In the present study, we have observed that the strain ET-1 of Bacillus subtilis, a producer of Iturin A, can present at least three different colony morphologies, which we arbitrarily called Rough, Smooth, and Mucoid morphotypes (R-, S-, and M-form). Performing HPLC analysis, a significant difference between the amounts of Iturin A produced by the three morphotypes was found. The morphotype R-form showed the highest productivity with yields about 10 and 100 times higher than morphotypes S and M, respectively. The results show that the production of Iturin A by B. subtilis could be strongly influenced by the phenotypic heterogeneity of cells within the inoculum. Indeed, we have observed that, pasteurizing the inoculum before seeding in order to improve the homogeneity removing the phenotypes less able to synthesize the Iturin A, its yields in a bench-scale production could be significantly improved. This can represent an important control factor also at industrial scale to improve the Iturin A yields, the robustness, the replicability, and consequently the cost-effectiveness of fermentation processes.
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Pei J, Kahl-McDonagh M, Ficht TA. Brucella dissociation is essential for macrophage egress and bacterial dissemination. Front Cell Infect Microbiol 2014; 4:23. [PMID: 24634889 PMCID: PMC3942807 DOI: 10.3389/fcimb.2014.00023] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2013] [Accepted: 02/10/2014] [Indexed: 12/24/2022] Open
Abstract
It has long been observed that smooth Brucella can dissociate into rough mutants that are cytotoxic to macrophages. However, the in vivo biological significance and/or mechanistic details of Brucella dissociation and cytotoxicity remain incomplete. In the current report, a plaque assay was developed using Brucella strains exhibiting varying degrees of cytotoxicity. Infected monolayers were observed daily using phase contrast microscopy for plaque formation while Brucella uptake and replication were monitored using an immunofluorescence assay (IFA). Visible plaques were detected at 4-5 days post infection (p.i.) with cytotoxic Brucella 16MΔmanBA at an MOI of 0.1. IFA staining demonstrated that the plaques consisted of macrophages with replicating Brucella. Visible plaques were not detected in monolayers infected with non-cytotoxic 16MΔmanBAΔvirB2 at an MOI of 0.1. However, IFA staining did reveal small groups of macrophages (foci) with replicating Brucella in the monolayers infected with 16MΔmanBAΔvirB2. The size of the foci observed in macrophage monolayers infected with rough Brucella correlated directly with cytotoxicity measured in liquid culture, suggesting that cytotoxicity was essential for Brucella egress and dissemination. In monolayers infected with 16M, small and large foci were observed. Double antibody staining revealed spontaneous rough mutants within the large, but not the small foci in 16M infected monolayers. Furthermore, plaque formation was observed in the large foci derived from 16M infections. Finally, the addition of gentamicin to the culture medium inhibited plaque formation, suggesting that cell-to-cell spread occurred only following release of the organisms from the cells. Taken together, these results demonstrate that Brucella-induced cytotoxicity is critical for Brucella egress and dissemination.
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Affiliation(s)
| | | | - Thomas A. Ficht
- Department of Veterinary Pathobiology, Texas A&M University and Texas Agricultural Experiment StationCollege Station, TX, USA
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Adone R, Muscillo M, La Rosa G, Francia M, Tarantino M. Antigenic, immunologic and genetic characterization of rough strains B. abortus RB51, B. melitensis B115 and B. melitensis B18. PLoS One 2011; 6:e24073. [PMID: 22065984 PMCID: PMC3204967 DOI: 10.1371/journal.pone.0024073] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Accepted: 07/29/2011] [Indexed: 11/19/2022] Open
Abstract
The lipopolysaccharide (LPS) is considered the major virulent factor in Brucella spp. Several genes have been identified involved in the synthesis of the three LPS components: lipid A, core and O-PS. Usually, Brucella strains devoid of O-PS (rough mutants) are less virulent than the wild type and do not induce undesirable interfering antibodies. Such of them proved to be protective against brucellosis in mice. Because of these favorable features, rough strains have been considered potential brucellosis vaccines. In this study, we evaluated the antigenic, immunologic and genetic characteristics of rough strains B.abortus RB51, B.melitensis B115 and B.melitensis B18. RB51 derived from B.abortus 2308 virulent strain and B115 is a natural rough strain in which the O-PS is present in the cytoplasm. B18 is a rough rifampin-resistan mutant isolated in our laboratory. The surface antigenicity of RB51, B115 and B18 was evaluated by testing their ability to bind antibodies induced by rough or smooth Brucella strains. The antibody response induced by each strain was evaluated in rabbits. Twenty-one genes, involved in the LPS-synthesis, were sequenced and compared with the B.melitensis 16M strain. The results indicated that RB51, B115 and B18 have differences in antigenicity, immunologic and genetic properties. Particularly, in B115 a nonsense mutation was detected in wzm gene, which could explain the intracellular localization of O-PS in this strain. Complementation studies to evaluate the precise role of each mutation in affecting Brucella morphology and its virulence, could provide useful information for the assessment of new, attenuated vaccines for brucellosis.
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Affiliation(s)
- Rosanna Adone
- Dipartimento Sanità Pubblica Veterinaria e Sicurezza Alimentare, Istituto Superiore di Sanità, Roma, Italy.
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Berditsch M, Afonin S, Ulrich AS. The ability of Aneurinibacillus migulanus (Bacillus brevis) to produce the antibiotic gramicidin S is correlated with phenotype variation. Appl Environ Microbiol 2007; 73:6620-8. [PMID: 17720841 PMCID: PMC2075075 DOI: 10.1128/aem.00881-07] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phenotype instability of bacterial strains can cause significant problems in biotechnological applications, since industrially useful properties may be lost. Here we report such degenerative dissociation for Aneurinibacillus migulanus (formerly known as Bacillus brevis) an established producer of the antimicrobial peptide gramicidin S (GS). Phenotypic variations within and between various strains maintained in different culture collections are demonstrated. The type strain, ATCC 9999, consists of six colony morphology variants, R, RC, RP, RT, SC, and SP, which were isolated and characterized as pure cultures. Correlations between colony morphology, growth, GS production, spore formation, and resistance to their own antimicrobial peptide were established in this study. We found the original R form to be the best producer, followed by RC, RP, and RT, while SC and SP yielded no GS at all. Currently available ATCC 9999(T) contains only 2% of the original R producer and is dominated by the newly described phenotypes RC and RP. No original R form is detected in the nominally equivalent strain DSM 2895(T) (=ATCC 9999(T)), which grows only as SC and SP phenotypes and has thus completely lost its value as a peptide producer. Two other strains from the same collection, DSM 5668 and DSM 5759, contain the unproductive SC variant and the GS-producing RC form, respectively. We describe the growth and maintenance conditions that stabilize certain colony phenotypes and reduce the degree of degenerative dissociation, thus providing a recommendation for how to revert the nonproducing smooth phenotypes to the valuable GS-producing rough ones.
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Affiliation(s)
- Marina Berditsch
- University of Karlsruhe (TH), Institute of Organic Chemistry, Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany.
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McIlroy AP, Axelrod AE, Mellon RR. The Influence of Sodium Acetate upon the Dissociation of a Strain of Hemolytic Streptococcus. J Bacteriol 2006; 56:547-53. [PMID: 16561604 PMCID: PMC518621 DOI: 10.1128/jb.56.5.547-553.1948] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- A P McIlroy
- Institute of Pathology of the Western Pennsylvania Hospital, University of Pittsburgh, Pittsburgh, Pennsylvania
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Wyss O, Stone WS, Clark JB. The Production of Mutations in Staphylococcus aureus by Chemical Treatment of the Substrate. J Bacteriol 2006; 54:767-72. [PMID: 16561418 PMCID: PMC526621 DOI: 10.1128/jb.54.6.767-772.1947] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- O Wyss
- Department of Bacteriology and the Genetics Laboratory, The University of Texas, Austin, Texas
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Stavitsky AB. CHARACTERISTICS OF PATHOGENIC SPIROCHETES AND SPIROCHETOSES WITH SPECIAL REFERENCE TO THE MECHANISMS OF HOST RESISTANCE. BACTERIOLOGICAL REVIEWS 2006; 12:203-55. [PMID: 16350122 PMCID: PMC440935 DOI: 10.1128/br.12.3.203-255.1948] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- A B Stavitsky
- Contribution No. 1176 from Gates and Crellin Laboratories, California Institute of Technology, Pasadena, California
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ROGOSA M, MITCHELL JA. Induced colonial variation of a total population among certain lactobacilli. J Bacteriol 2004; 59:303-8. [PMID: 15421959 PMCID: PMC385753 DOI: 10.1128/jb.59.2.303-308.1950] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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GOODLOW RJ, MIKA LA, BRAUN W. The effect of metabolites upon growth and variation of Brucella abortus. J Bacteriol 2004; 60:291-300. [PMID: 14774349 PMCID: PMC385879 DOI: 10.1128/jb.60.3.291-300.1950] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Ugalde JE, Czibener C, Feldman MF, Ugalde RA. Identification and characterization of the Brucella abortus phosphoglucomutase gene: role of lipopolysaccharide in virulence and intracellular multiplication. Infect Immun 2000; 68:5716-23. [PMID: 10992476 PMCID: PMC101528 DOI: 10.1128/iai.68.10.5716-5723.2000] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2000] [Accepted: 07/04/2000] [Indexed: 11/20/2022] Open
Abstract
Smooth lipopolysaccharide (LPS) of Brucella abortus has been reported to be an important virulence factor, although its precise role in pathogenesis is not yet clear. While the protective properties of LPS against complement are well accepted, there is still some controversy about the capacity of rough mutants to replicate intracellularly. The B. abortus phosphoglucomutase gene (pgm) was cloned, sequenced, and disrupted. The gene has a high index of identity to Agrobacterium tumefaciens pgm but is not part of the glycogen operon. A B. abortus null mutant lacks LPS O antigen but has an LPS core with an electrophoretic profile undistinguishable from that of the wild-type core, suggesting that glucose, galactose, or a derivative of these sugars may be part of the linkage between the core and the O antigen. This mutant is unable to survive in mice but replicates in HeLa cells, indicating that the complete LPS is not essential either for invasion or for intracellular multiplication. This behavior suggests that the LPS may play a role in extracellular survival in the animal, probably protecting the cell against complement-mediated lysis, but is not involved in intracellular survival.
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Affiliation(s)
- J E Ugalde
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús, Universidad Nacional de General San Martín, Buenos Aires, Argentina
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Strick J. Evolution of microbiology as seen in the textbooks of Edwin O. Jordan and William H. Park. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 1999; 72:321-8. [PMID: 11049163 PMCID: PMC2579028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Historians of science account the appearance of textbooks as an important step in the formation and consolidation of a new discipline. The texts of Park and Jordan were both very important in this light; however; they also can be used as a gauge of changing concepts within microbiology in the first four decades after its consolidation as a discipline, 1900-1940. This paper tracks these important texts and through them changing attitudes toward several important concepts: bacterial variation, human/bovine tuberculosis, and the existence of a non-symptomatic carrier state in infectious disease. The two texts are also compared regarding their view of microbes as pathogens vs. microbes as important and ubiquitous ecological agents.
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Affiliation(s)
- J Strick
- Department of Biology, Arizona State University, Tempe 85287-1501, USA
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Allen CA, Adams LG, Ficht TA. Transposon-derived Brucella abortus rough mutants are attenuated and exhibit reduced intracellular survival. Infect Immun 1998; 66:1008-16. [PMID: 9488389 PMCID: PMC108009 DOI: 10.1128/iai.66.3.1008-1016.1998] [Citation(s) in RCA: 140] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/1997] [Accepted: 12/19/1997] [Indexed: 02/06/2023] Open
Abstract
The O antigen of Brucella abortus has been described as a major virulence determinant based on the attenuated survival of fortuitously isolated rough variants. However, the lack of genetic definition of these mutants and the virulence of naturally occurring rough species, Brucella ovis and Brucella canis, has confused interpretation. To better characterize the role of O antigen in virulence and survival, transposon mutagenesis was used to generate B. abortus rough mutants defective in O-antigen presentation. Sequence analysis of DNA flanking the site of Tn5 insertion was used to verify insertion in genes encoding lipopolysaccharide (LPS) biosynthetic functions. Not surprisingly, each of the rough mutants was attenuated for survival in mice, but unexpected differences among the mutants were observed. In an effort to define the basis for the observed differences, the structure of the rough LPS and the sensitivity of these mutants to individual killing mechanisms were examined in vitro. All of the B. abortus rough mutants exhibited a 4- to 5-log-unit increase, compared to the smooth parental strain, in sensitivity to complement-mediated lysis. Little change was evident in the sensitivity of these organisms to hydrogen peroxide, consistent with an inability of O antigen to exclude relatively small molecules. Sensitivity to polymyxin B, which was employed as a model cationic, amphipathic peptide similar to defensins found in phagocytic cells, revealed survival differences among the rough mutants similar to those observed in the mouse. One mutant in particular exhibited hypersensitivity to polymyxin B and reduced survival in mice. This mutant was characterized by a truncated rough LPS. DNA sequence analysis of this mutant revealed a transposon interruption in the gene encoding phosphomannomutase (pmm), suggesting that this activity may be required for the synthesis of a full-length core polysaccharide in addition to O antigen. B. abortus O antigen appears to be essential for extra- and intracellular survival in mice.
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Affiliation(s)
- C A Allen
- Department of Veterinary Pathobiology, Texas A&M University, College Station 77843-4467, USA
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Affiliation(s)
- L D Smith
- Department of Molecular Biology, Scripps Clinic and Research Foundation, San Diego, California
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Simpson LM, White VK, Zane SF, Oliver JD. Correlation between virulence and colony morphology in Vibrio vulnificus. Infect Immun 1987; 55:269-72. [PMID: 2432016 PMCID: PMC260315 DOI: 10.1128/iai.55.1.269-272.1987] [Citation(s) in RCA: 162] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Of 38 isolates of Vibrio vulnificus examined, all avirulent strains produced only translucent colonies. All virulent strains, with the exception of biogroup 2 (eel pathogens), exhibited both opaque and translucent colonies. Isogenic morphotypes were examined for a variety of phenotypic and virulence traits. Only the ability to utilize transferrin-bound iron and the presence of a surface polysaccharide were found to correlate with colony opacity and virulence.
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DeVoe IW, Gilchrist JE. Piliation and colonial morphology among laboratory strains of meningococci. J Clin Microbiol 1978; 7:379-84. [PMID: 99453 PMCID: PMC274971 DOI: 10.1128/jcm.7.4.379-384.1978] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Colonial morphology and piliation were studied on twelve strains from various serogroups of Neisseria meningitidis. Six different colony types (M1 to M6) were identified. Most strains elaborated only an M1 colonial type, which is similar to gonococcus T4. Several combinations of piliation and colonial morphology were observed: (i) colonial variation in which neither parent nor variant were piliated; (ii) colonial variation involving piliated and nonpiliated cells; (iii) dissociation of piliated from nonpiliated cells with no colonial change; and (iv) colonial variation in which both variants were piliated but with distinctly different pili. Results of this study demonstrate that correlations between piliation and colony morphology within N. meningitidis are exceptions rather than the rule.
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Abstract
Baker, Phillip J. (University of Wisconsin, Madison), and J. B. Wilson. Chemical composition and biological properties of the endotoxin of Brucella abortus. J. Bacteriol. 90:895-902. 1965.-The ability of endotoxin to induce hypoferremia in mice was used to measure the specific activity of various endotoxin preparations of Escherichia coli and Brucella abortus and to determine the endotoxin content of several strains of B. abortus differing in virulence for guinea pigs. The endotoxin preparations from E. coli possessed greater biological activity than those from B. abortus. The same types of B. abortus endotoxin preparations, whether obtained from strains of high or low virulence, had about the same activity. Although differences in endotoxin content were noted among several strains of B. abortus of different virulence, there appeared to be no correlation between endotoxin content and virulence. Chemical analyses of B. abortus and E. coli endotoxins, based upon nitrogen, phosphorus, fatty acid ester, fatty acid amide, total fatty acids, hexose, and hexosamine content, revealed differences in chemical composition; however, these differences could not be correlated with differences in biological activity. The same types of endotoxin preparations, whether obtained from strains of B. abortus of high or low virulence, were similar in chemical composition and in biological activity. A correlation between the ability of endotoxin to induce hypoferremia and its lethal effects in mice is suggested. In general, endotoxin preparations of high hypoferremic activity had low mouse ld(50) values.
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Abstract
Baker, Phillip J. (University of Wisconsin, Madison), and J. B. Wilson. Hypoferremia in mice and its application to the bioassay of endotoxin. J. Bacteriol. 90:903-910. 1965.-The ability of endotoxin to induce hypoferremia in mice was used for the bioassay of endotoxin. A marked depression in the serum-iron levels of mice occurred 12 hr after the intraperitoneal injection of 0.01 to 100 mug of Escherichia coli endotoxin; similar results were obtained with 1.0 to 100 mug of Brucella abortus endotoxin. This biological response to endotoxin appeared to be specific, reproducible, and dose-dependent. As heat-killed cells of B. abortus and E. coli were also able to induce hypoferremia, this bioassay could be employed for the determination of the endotoxin content of killed-cell preparations. Treatment of endotoxin by acid hydrolysis, acetylation, or pyridine-formic acid greatly diminished the hypoferremic response as well as its lethality for mice. Pretreatment of mice with Thorotrast had little effect upon the ability of endotoxin to induce hypoferremia; however, a stimulation of the activity of the reticuloendothelial system (RES) by treatment of mice with triolein markedly reduced the ability of endotoxin to induce hypoferremia. The relationship between the hypoferremic response to endotoxin and alterations in the activity of the RES are discussed.
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BRAUN W, ALTENBERN R, KELSH J, SANDOVAL H. Anoxia as a major factor causing population changes in antiserum-containing cultures. J Bacteriol 1956; 71:417-20. [PMID: 13319254 PMCID: PMC357819 DOI: 10.1128/jb.71.4.417-420.1956] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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HARTMAN RS, EIGELSBACH HT, BATEMAN JB, BRAUN W, HERRING R, RODGERS RD. An electrophoretic method for the assay of bacterial variants. Appl Microbiol 1953; 1:178-83. [PMID: 13066029 PMCID: PMC1056899 DOI: 10.1128/am.1.4.178-183.1953] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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LYONS DC. The present concept of cellular and environmental influences on mouth-inhabiting acidogenic bacteria; a review. ORAL SURGERY, ORAL MEDICINE, AND ORAL PATHOLOGY 1952; 5:1104-18. [PMID: 13003146 DOI: 10.1016/0030-4220(52)90214-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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BRAUN W, GOODLOW RJ, KRAFT M, ALTENBERN R, MEAD D. THE EFFECTS OF METABOLITES UPON INTERACTIONS BETWEEN VARIANTS IN MIXED BRUCELLA ABORTUS POPULATIONS. J Bacteriol 1951; 62:45-52. [PMID: 14861158 PMCID: PMC386083 DOI: 10.1128/jb.62.1.45-52.1951] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Braun W. STUDIES ON BACTERIAL VARIATION AND SELECTIVE ENVIRONMENTS I. : The Nature of the Selective Serum Factor Affecting the Variation of Brucella Abortus. J Bacteriol 1949; 58:291-7. [PMID: 16561785 PMCID: PMC385627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023] Open
Affiliation(s)
- W Braun
- Department of Veterinary Science, University of California, Berkeley, California
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Ryan FJ, Schneider LK. THE CONSEQUENCES OF MUTATION DURING THE GROWTH OF BIOCHEMICAL MUTANTS OF ESCHERICHIA COLI IV. : The Mechanism of inhibition of Histidine-independent Bacteria by Histidineless Bacteria. J Bacteriol 1949; 58:201-13. [PMID: 16561773 PMCID: PMC385611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023] Open
Affiliation(s)
- F J Ryan
- Department of Zoology, Columbia University, New York 27, New York
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THE CONSEQUENCES OF MUTATION DURING THE GROWTH OF BIOCHEMICAL MUTANTS OF ESCHERICHIA COLI IV. J Bacteriol 1949; 58:201-13. [DOI: 10.1128/jb.58.2.201-213.1949] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Boivin A. Les variations antigéniques des Bactéries et leur déterminisme possible. Med Microbiol Immunol 1948. [DOI: 10.1007/bf02178102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Hoerlein BF. The Inhibiting Effect of Normal Serum and Its Gamma Globulin Fraction upon the Variation of Staphylococcus aureus. J Bacteriol 1948; 56:139-40. [PMID: 16561540 PMCID: PMC518554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023] Open
Affiliation(s)
- B F Hoerlein
- Department of Veterinary Science, University of California, Berkeley, California
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