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At least 19 recordsLinked to original sources
PubMed1976

Evolution and taxonomy in the genus Brucella: progesterone induction of filterable forms of Brucella abortus type 2 with revertant characteristics essentially indistinguishable in vitro from those of Brucella ovis.

An organism essentially indistinguishable from Brucella ovis, as determined by conventional and manometric techniques of identifying Brucella organisms, was derived in vitro from a strain of Brucella abortus type 2. The basic mechanism responsible for derivation of this organism was incomplete reversion of the L-forms to their original parental characteristics. The agent used to induce the L-forms was a physiologic concentration of progesterone incorporated in the growth medium.

Biological Evolution↗
PubMed1975

[Isolation of "Brucella suis" biotype 5 from a bitch, in Madagascar. Validity of the species name "Brucella canis" (author's transl)].

A Gram-negative organism isolated from a btich, in Madagascar, was examined by bacteriologic, immunologic and metabolic methods, in parallel with cultures representative of the Brucella species. The organism fits well into the genus Brucella on the basis of its growth, biochemical and antigenic characteristics and was found to have the metabolic pattern on L-asparagine (-), L-arginine (+) and DL-ornithine (+) that identifies and defines the species Brucella suis. It is of rough colonial morphology and electron microscopy showed a cell wall structure similar to that of other rough Brucella. By all the other recommended criteria for btotype identification it was found to be similar to Brucella suis biotype 5 best known as Brucella canis. In contrast to the strains of this biotype, it grows on basic fuchsin at 20 mug/ml and on safranine O at 200 mug/ml. These differences obtained with just one strain would not justify by now the proposal for a new biotype. We favor the designation Brucella suis biotype 5 proposed by Meyer, and the validity of Brucella canis (Carmichael and Bruner) as a separate species is discussed. It is the first strain of Brucella isolated in Madagascar.

Abortion, Induced↗
PubMed1975

[Brucella isolated in France: identification and typing. I. -- Brucella abortus (author's transl)].

Two hundred and eight strains of Brucella isolated from cattle and 5 isolated from man in various areas of France, during a two-year period from 1972 to 1974, were examined by all methods recommended by the Subcommittee on Taxonomy of the genus Brucella and were found to have the same characteristics that identify and define the species Brucella abortus. Of the 213 strains, 105 (49,29 p. 100) were biotype I, 103 strains (48,36 p. 100) biotype 3, three strains (1,41 p. 100) biotype 4 and 2 strains (0,94 p. 100) biotype 2. The distribution of Brucella abortus biotypes isolated from cattle and man in France is reviewed and compared with the data from our sample. It corroborates the epidemiologic importance of Brucella abortus biotype 3, just after type 1, and the absence of biotypes 5 to 9(1) in France. Five strains of Brucella abortus biotype 3, originating from a well-defined geographical area, are ureaseless. This new biochemical character distinguishes these strains from the main group of biotype 3 and is discussed from an epidemiological and methodological point of view. Data on the oxydative rates obtained on 12 substrates by the 213 strains are presented in graphic form which reveals a metabolic profile for the species Brucella abortus. The interest of this graphic presentation is discussed and its use should be recommended.

Animals↗
PubMed2026

Comparative analysis of lipopolysaccharide lipid A structure and its biosynthetic genes in the plant-associated bacteria Brucella cytisi and Brucella lupini.

The genus Brucella comprises important human and animal pathogens, as well as numerous environmental and symbiotic species. Lipopolysaccharide (LPS), a major component of the outer membrane of Gram-negative bacteria, plays a crucial role in bacterial physiology and host interactions. In this study, the structures of lipid A, the hydrophobic anchor of lipopolysaccharide, isolated from two plant-associated strains, Brucella cytisi ESC1ᵀ and Brucella lupini LUP21ᵀ, were presented. Lipid A preparations were structurally characterized using chemical methods, MALDI-TOF mass spectrometry, and nuclear magnetic resonance spectroscopy. The obtained results indicated that both lipid A molecules have almost identical structures. Their sugar backbones consist exclusively of 2,3-diamino-2,3-dideoxy-d-glucose (d-GlcpN3N). Phosphate residues were connected to distal and proximal GlcpN3N in approximately half of the lipid A molecules. Fatty acid analysis revealed the presence of C14:0 (3-OH), C16:0 (3-OH), and traces of C18:0 (3-OH). All of these were primary fatty substituents of the sugar backbone and were amide-linked residues. Lactobacillic acid C19:0cyc and 27-hydroxyoctacosanoic acid (C28:0 (27-OH)) were found as ester-linked secondary acyl residues. In turn, C28:0 (27-OH) was partly esterified by a 3-hydroxybutyroyl residue. Two unsubstituted 3-hydroxyfatty acids were linked exclusively to the proximal d-GlcpN3N residue. It was pointed out that sequences of putative genes encoding enzymes required for lipid A biosynthesis and genes encoding specific enzymes involved in structural modifications of lipid A occurring in the genomes of both bacterial species are almost identical. The high sequence similarity of these proteins reflects the observed similarities in the lipid A structures in both investigated Brucella species.

Brucella↗
PubMed1976

The serological response to rough and smooth brucella antigens in cattle vaccinated with Brucella abortus strain 45/20 adjuvant vaccine.

Cattle not previously exposed to Brucella abortus responded to a single dose of Br. abortus 45/20 adjuvant vaccine by producing low titres of agglutinins for rough brucella antigens and little or no agglutinins to the smooth antigens. Moderate titres of non-agglutinating antibodies reacting with both rough and smooth antigens were also produced. After a second dose of 45/20 vaccine higher titres of rough agglutinins and low titres of antibodies reacting with smooth antigens were produced. High titres of non-agglutinating antibodies reacting with both rough and smooth antigens were also produced. Animals previously exposed to smooth Br. abortus, either as strain 19 vaccine or virulent organisms, produced high titres of antibodies to smooth antigens soon after vaccination with 45/20 adjuvant vaccine. High titres of antibodies reacting with rough and smooth antigens were also produced. The evidence suggests that the Br. abortus strain 45/20 shares a surface antigenic component with smooth brucellae. The possible relationship of this to the protective antigen is discussed.

Animals↗
PubMed1977

Enhancement activity of anti-brucella sera in experimental Brucella abortus infection in mice.

The passive transfer of rabbit anti-brucella sera promotes the multiplication of Brucella abortus in the spleen of mice infected intravenously with a low dose of this bacteria. The enhancement activity of the anti-brucella sera is related to their modes of preparation in rabbits. The agglutinin titers of all these antisera were relatively high, while there was some discrepancies in their content in haemagglutinating, immune adherence and complement fixing antibodies.

Animals↗
PubMed1977

Agglutinins to Coxiella burnetii and Brucella spp, with particular reference to Brucella canis, in wild animals of southern Texas.

The prevalence of agglutinins to Coxiella burnetii and Brucella spp, particularly Brucella canis, was determined in 269 wild animals (14 species) in southern Texas. Serologic evidence of coxiellosis and brucellosis, including B canis infection, was shown for coyotes, raccoons, opossums, badgers, jackrabbits, and feral hogs. Using the microagglutination test, the seroprevalence of C burnetii, phases I and II (titer greater than or equal to 4) was 4.1 and 27.9%, respectively. For brucella agglutinins, prevalence rates were 7.1, 8.9, and 6.7%, as determined by the brucellosis card test, the rapid slide agglutination test, and the salt 2-mercaptoethanol tube agglutination (titer greater than or equal to 50) test, respectively.

Agglutinins↗
PubMed1979

Comparison of Brucella abortus and Brucella melitensis infections of mice and their effect on acquired cellular resistance.

By using mice infected with strains of Brucella abortus and Brucella melitensis we examined the histological responses to infection, the relationship of histology to persistence of organisms, and the relation of persistence of organisms to the acquisition of acquired cellular resistance (ACR). Infection with B. abortus resulted in well-formed granulomas in the livers, which persisted for more than 30 days. In contrast, infection with B. melitensis produced microabscesses in the livers which resolved before 30 days. The clearance of organisms from the tissues was also different. A total of 30 days after infection, large numbers of viable bacteria were recovered from the tissues of B. abortus-infected mice whereas bacteria were no longer recoverable from B. melitensis-infected animals. ACR to Listeria monocytogenes, another intracellular pathogen, persisted for more than 30 days in B. abortus-infected mice but waned rapidly in B. melitensis-infected animals. This disappearance of ACR due to B. melitensis paralleled the clearance of bacteria from the tissues.

Animals↗
PubMed1978

T-independent responses in B cell-defective CBA/N mice to Brucella abortus and to trinitrophenyl (TNP) conjugates of Brucella abortus.

CBA/N mice have an X-linked immune defect in B lymphocyte function which leads to their inability to respond to several thymus-independent antigens. We report here that these mice and immunologically defective F1 male (CBA/N X DBA/2N) mice can respond to Brucella abortus and to 2,4,6-trinitrophenyl derivatives of Brucella abortus (TNP-BA). These responses can be obtained in vivo and in vitro and are thymus-independent by the criteria that (a) they can be transferred to irradiated recipients by bone marrow cells and anti-Thy-1.2 and complement-treated spleen cells; (b) that nu/nu BALB/c spleen cells respond to TNP-BA in vitro; and (c) that anti-Thy-1.2 and complement-treated (CBA/N X DBA/2N)F1 male spleen cells respond to TNP-BA in vitro. B. abortus and TNP-BA are poor polyclonal B cell activators (PBA) and poor B cell mitogens, unlike lipopolysaccharide which is both a powerful PBA and B cell mitogen. These results therefore indicate that mice with the CBA/N B cell defect can respond to some thymus-independent antigens, namely TNP-BA, and as shown previously, TNP-LPS, although not to other thymus-independent antigens. This, in turn, suggests that thymus-independent antigens may be subdivided on the basis of their ability or inability to stimulate responses by CBA/N B lymphocytes.

Animals↗
PubMed1975

Serologic studies of Brucella suis and Brucella canis.

Brucella suis strain 3b and Brucella canis strain RM-6-66 were grown on tryptose agar, and aqueous ether extracts were prepared from the cells. The aqueous phase was clarified by centrifugation for a total of 10 hours at 144,700 times g and fractionated with gels and with diethylaminoethyl (DEAE) cellulose. Two fractions from B suis and 1 fraction from B canis were reactive in the indirect hemagglutination test. The sensitizing ability was destroyed by pronase, but was unaffected by ribonuclease or deoxyribonuclease. Apparently, protein or one of its subunits has an important role in antigenic specificity relating to indirect hemagglutination activity. Results in immunoelectrophoretic analysis indicated at least 22 antigens were in the ultracentrifugal supernate (144,700 times g) of B suis and 31 antigens were in a similar supernate of B canis. Results in immunodiffusion and agglutination absorption studies indicated a close relationship existed between B suis and B canis.

Animals↗
PubMedDate not supplied

Resistance of Brucella abortus infected mice to intravenous or intraperitoneal Brucella reinfection.

The development of acquired resistance to Brucella abortus was studied in mice infected intravenously with small numbers of live CO2-dependent B. abortus 544 used as vaccinal strain. CO2-independent B. abortus was used as challenge strain. The influence of several parameters in the development of acquired resistance was examined: vaccination--challenge interval, challenge route, dose of challenge, challenge-sacrifice interval. The behavior of the challenge strain in normal mice depended on the size of the inoculum. After an intravenous inoculum of about 1 X 10(6) bacteria, the level of infection in the liver or the spleen followed three phases: a phase of increase of the viable counts, a phase of decrease, and a phase of plateau. The decreasing phase was more pronounced in liver than in spleen. After an intraperitoneal injection of the same dose of bacteria, an infection developed following approximately the same pattern, except during the first day of infection. One month after vaccination by an inoculum of about 1 X 10(4) viable B. abortus, an accelerated appearance of the decreasing phase prevented almost completely the multiplication of an intravenous challenge of about 1 X 10(6) B. abortus in the spleens. In the livers the same phenomenon took place after a small increase of the bacterial population. After an intraperitoneal challenge, the numbers of Brucella isolated from the spleens and livers of vaccinated mice first fell sharply to practically nothing around the sixth day, and then rose to reach a phase of slow increase or of plateau until the twenty-fourth day. In our experimental conditions, the vaccine population remained undisturbed by the reinfecting inoculum.

Animals↗
PubMed1976

Evolution and taxonomy in the genus Brucella: contemporary evolutionary status of the species Brucella abortus.

The biotypes in the species Brucella abortus were arranged according to the sequential flow in the alterations of their characteristics. This reordering of the biotypes indicated that the organism currently classified as B abortus type 2 is the parent organism of all the biotypes in this species. However, laboratory-selected mutants from B abortus type 2 had characteristics that were mimetic, but not duplicative, of their naturally occuring counterparts. Evidence which indicates this phenomenon is related to permeability of the cell wall is presented and discussed.

Brucella↗
PubMed1979

Cell-mediated immune responses in cattle adult-vaccinated with Brucella abortus strain 19 and in cattle infected with Brucella abortus field strain.

Cell-mediated immune responses in cattle adult-vaccinated with Brucella abortus strain 19, cattle infected with B abortus field strain, and nonexposed cattle were studied by an in vitro lumphocyte-stimulation test (LST). Lymphocytes were prepared from peripheral bovine blood by the Ficoll-diatrizoate technique, and results were assayed for [3H]thymidine incorporation into DNA by liquid scintillation spectrometry. Serotests and bacteriologic isolation attempts were conducted simultaneously with LST. Lymphocytes from cattle infected with field strains had significantly (P = 0.01) higher specific lymphocyte-stimulation inexposed controls. The LST, the serum standard-tube agglutination test (STT), the Rivanol (RIV) test, and the complement-fixation (CF) test correctly classified cattle from which field strains and strain 19 of B abortus were isolated. The LST was negative in cattle vaccinated with B abortus strain 19 (nonshedding), but the three serotests had many false-positive reactions. The CF test had the least false-positive reaction, followed by the RIV test, and the STT was the least specific. Well before the three serotests became positive, the LST was positive in samples from some cattle during the incubation period of the infection. There was little or no correlation between cell-mediated immune responses (as measured by LST) and serum antibody responses (as measured by STT, RIV test, and CF test) in vaccinated but culture-negative cattle and in some nonvaccinated cattle during the incubation period.

Agglutination Tests↗
PubMed1978

Specific lymphocyte stimulation in cattle naturally infected with strains of Brucella abortus and cattle vaccinated with Brucella abortus strain 19.

Cell-mediated immune responses in cattle naturally infected with strains of Brucella abortus and in cattle vaccinated with B abortus strain 19 during calfhood were studied by an in vitro lymphocyte-stimulation procedure. Lymphocytes were prepared from peripheral bovine blood by the Ficoll-diatrizoate technique, suspended in RPMI-1640 medium (1.5 X 10(6) lymphocytes/ml), cultured with B abortus-soluble antigen or phytohemagglutinin, and incubated for 6 days. Sixteen hours prior to termination of incubation, cultures were labeled with 1 muCi of [3H]thymidine (3HdT) and, after harvesting, assayed for 3HdT incorporation into DNA by liquid scintillation spectrometry. Lymphocytes from cattle with bacteriologically confirmed isolation of B abortus underwent a significantly higher lymphocyte stimulation with B abortus-soluble antigen than did cattle vaccinated with B abortus strain 19 during calfhood (P less than 0.005). Standard seroagglutination tests were conducted simultaneously with lymphocyte-stimulation tests, but there was no apparent correlation between levels of humoral antibodies and the cell-mediated immune responses as measured by in vitro specific lymphocyte stimulation.

Agglutination Tests↗