| effectivity of rev 1 vaccine in rams against brucella ovis infection. | vaccination with rev 1 at four months of age protected rams against experimental infection with brucella ovis. a double vaccination did not improve immunity whereas rams vaccinated later in life showed a decreased immunity to the infection. lesions and complement fixation reactions were found to be inadequate criteria for the diagnosis of the disease in the individual ram. | 1975 | 1223287 |
| characterization of brucella ovis lipopolysaccharide and its use for diagnosis of ram epididymitis by enzyme-linked immunosorbent assay. | rough lipopolysaccharide, extracted by a mixture of phenol, chloroform, and petroleum ether from freeze-dried brucella ovis cells with a yield of 0.71%, contained relatively small amounts of protein and nucleic acid contaminants as compared with lipopolysaccharides from other brucellae. the crude lipopolysaccharide was suitable as a diagnostic antigen in an enzyme-linked immunosorbent assay for the sensitive and specific detection of ram epididymitis caused by b. ovis infection. in comparative s ... | 1984 | 6394618 |
| immunochemical characterization of rough brucella lipopolysaccharides. | lipopolysaccharides (lps) were extracted from rough strains of brucella abortus and brucella melitensis and from strains of the naturally occurring rough species brucella ovis and brucella canis. brucella rough lipopolysaccharides (r-lps) were readily distinguished from brucella smooth lipopolysaccharides (s-lps) and enterobacterial r-lps, by their chemical, physical, and serological characteristics. b. ovis r-lps was differentiated from b. abortus, b. melitensis, and b. canis r-lps by its react ... | 1984 | 6421737 |
| differentiation of brucella ovis from brucella abortus by gas-liquid chromatographic analysis of cellular fatty acids. | the cellular fatty acid composition of brucella ovis and brucella abortus strains was determined by gas-liquid chromatography. both species were characterized by the presence of fatty acids 16:0, 17:0, 17:0 cyclopropane, 18:0, 18:1, and 19:0 cyclopropane; b. ovis also contained some 15:0. there were differences in the relative proportions of the fatty acids present, and it was possible to differentiate b. ovis from b. abortus on the basis of the absence of 15:0, lower concentrations of 17:0 and ... | 1984 | 6432837 |
| protection of rams against epididymitis by a brucella ovis-vitamin e adjuvant vaccine. | rams vaccinated at 7 and 8 months of age with a b. ovis-vitamin e adjuvant vaccine had increased antibody titers compared with freund's incomplete adjuvant or commercial bacterin vaccinated rams. the percent overall infectivity in an experimental infection of b. ovis-vitamin e adjuvant vaccinated rams was 22% compared to 44% for b. ovis-freund's incomplete adjuvant or bacterin vaccinated rams and 67% for control. | 1984 | 6506451 |
| serodiagnosis of histophilus ovis-associated epididymitis in rams. | an elisa for the detection of antibodies to histophilus ovis was used to evaluate the association of epididymal lesions in rams with serologic response to his ovis. comparison of elisa results for his ovis in groups of rams with epididymal lesions with elisa results of clinically normal rams (control group) revealed a significant difference (p less than 0.01) between the control group and those rams from which his ovis was isolated. a significant difference (p less than 0.01) was noticed between ... | 1988 | 3348531 |
| letter: brucella ovis vaccination of rams. | | 1975 | 1060006 |
| brucella ovis-induced abortion in ewes. | aborted fetuses and placental tissue from ewes in 2 flocks were submitted for diagnostic examinations. brucella ovis was isolated from fetal lung or abomasal contents, or both. placentitis was a consistent gross lesion. microscopic lesions included suppurative pneumonia and placentitis. | 1983 | 6618987 |
| interaction of brucella ovis with ovine tissue extracts. | | 1983 | 6636477 |
| comparison of different antigenic preparations for the detection of ovine serum antibodies against brucella ovis by elisa. | an enzyme-linked immunosorbent assay has been developed for the detection of antibodies against brucella ovis using serum from control rams (con-s), naturally infected rams (inf-s), rams inoculated intravenously with b. ovis (iv-s) and rams vaccinated intramuscularly (im-s). the serum was titrated by serial double dilutions from 1/25 to 1/25,600 against whole bacteria, b. ovis lipopolysaccharide and a detergent-extracted component of the outer membrane complex of b. ovis as antigens immobilised ... | 1983 | 6651682 |
| [comparative diagnostic studies of epididymitis in rams caused by brucella ovis]. | semen samples taken from 21 rams with pronounced pathologic changes were studied in a complex way to establish the etiology contributing to the deterioration of the semen quality. the complement-fixation test was applied with blood serum and semen plasma along with the microscopic study of the semen for the excretion of brucella ovis organisms and a clinical examination. the following results were obtained: 1. the semen plasma of 90.5 per cent of the rams was positive for brucella ovis. a total ... | 1976 | 951934 |
| ovine contagious epididymitis: a review. | ovine contagious epididymitis is predominantly associated with brucella ovis, actinobacillus seminis and a variety of organisms including histophilus ovis. transmission occurs venereally or by homosexual activity and, in the case of actinobacillus seminis, ewe to lamb transmission is probably important. a chronic infection, mainly in the cauda epididymis may result in formation of spermatic granulomata and a reduction in ram fertility. eradication of ovine brucellosis can be achieved by serologi ... | 1982 | 6762755 |
| [comparative investigations using the complement fixation test and the agar gel immunodiffusion test to reveal the presence of brucella-ovis-antibodies (author's transl)]. | | 1980 | 6772421 |
| binding of bacteria from the genus brucella to human b lymphocytes. | in previous studies, we have shown that various lymphocyte subpopulations bind different strains of bacteria of different genera and species. among these bacteria was a strain of brucella melitensis which bound to all human b lymphocytes. to determine whether the binding of b. melitensis to human b lymphocytes was strain, species, or genus characteristic, we tested the binding of b. melitensis, brucella abortus, brucella ovis, brucella suis, brucella canis and brucella neotomae to human normal a ... | 1981 | 6783546 |
| association of sexual experience with isolation of various bacteria in cases of ovine epididymitis. | testicles from rams in flocks experiencing ram epididymitis in idaho and eastern oregon were cultured. twenty-six breeding rams from 6 flocks were cultured and only brucella ovis was isolated. virgin rams (65) harbored numerous species of small fastidious gram-negative rods, including actinobacillus actinomycetemcomitans, haemophilus spp, moraxella spp, and pasteurella spp. thus, there appeared to be 2 separate disease entities, dependent on sexual experience of the animal. | 1983 | 6833070 |
| restriction endonuclease analysis of brucella ovis and other brucella species. | brucella ovis dna was analysed by using 11 different restriction endonucleases. the most clearly resolved dna fragment patterns were obtained after digestion with the enzyme hind iii. when dna preparations from 35 strains of b. ovis were digested with this enzyme, the fragment patterns appeared to be identical. the patterns obtained after hind iii digestion of dna from one strain each of b. abortus, b. canis and b. melitensis were more similar to each other than to the b. ovis pattern. | 1985 | 2996213 |
| diagnosing ovine epididymitis by immunofluorescence. | antisera against actinobacillus seminis, brucella ovis and corynebacterium pseudotuberculosis were prepared in adult female goats. specific immunofluorescence was observed in cultural smears of a seminis, b ovis and c pseudotuberculosis by the direct technique and in smears of a seminis also by the indirect technique. individual organisms could be recognised. specific fluorescence of a seminis was readily detected in semen. the results indicate that immunofluorescence may offer an effective meth ... | 1980 | 7020228 |
| sensitivity and specificity of two microtitre complement fixation tests for the diagnosis of brucella ovis infection in rams. | an investigation was made into microtitre complement fixation test (cft) procedures suitable for the serological diagnosis of naturally occurring brucella ovis infection in rams. a procedure similar to the australian standard procedure for bovine brucellosis was unsatisfactory when applied to sheep. modification of the procedure by use of an initial serum and anticomplementary control dilution of 1:8 and increasing complement fixation time to 60 minutes at 37 degrees c, greatly improved the effi ... | 1982 | 7082234 |
| epidemiological studies on ovine brucellosis in selected ram flocks. | the epidemiology of ovine brucellosis was investigated in 6 ram flocks in which anomalous reactions to the complement fixation test was recorded. it was shown that rams can become infected as young as 4 months of age. naturally infected animals have an epididymitis and excrete brucella ovis in their semen or they may only show a serological response for a short time then recover. the base line titres of chronically infected animals stay relatively constant. the importance of abortive infection a ... | 1982 | 7150131 |
| efficacy of brucella melitensis rev. 1 vaccine against brucella ovis infection in rams. | the efficacy of brucella melitensis strain rev. 1 vaccine against a brucella ovis experimental infection was judged on 30 rams, 15 of which had received 8.5 x 10(8) rev. 1 at the age of 4 months. all were challenged 9 months later by conjunctival route with 5 x 10(8) b. ovis. the 30 rams were killed three months after challenge and were autopsied. genital and other organs and lymph-nodes were searched for b. ovis. only a few organs and lymph-nodes of three vaccinated rams shed b. ovis, contrary ... | 1982 | 7168540 |
| [pathomorphological changes in brucella ovis-infected sheep]. | in spontaneously infected with br. ovis rams, as well as in experimentally infected with the same infection sheep and rams, besides the morphological changes in the epididymis with some part of the animals, we also observed granulomas in the lungs with a specific morphological structure. the presence of br. ovis was proved in a number of organs such as the epididymis, the seminal ampullae, the lungs, the kidneys, the liver and the myocardium. in spite of the presence of bacteria no morphological ... | 1980 | 7222458 |
| the pathology of bacterial infection of the genitalia in rams. | details are given of the macroscopic and histopathological changes brought about by infection of the genitalia of rams by bacteria other than brucella ovis. lesions of the seminal vesicles and ampullae are described which, in addition to the clinically evident lesions of the testes and epididymis, could be an important reasons for impaired fertility. the name "bacterial infection of the genitalia", abbreviated to big, is suggested as a more appropriate designation for this condition than "ram ep ... | 1980 | 7231922 |
| protection of rams against brucella ovis infection by brucella melitensis rev. 1 vaccine. | | 1981 | 7324641 |
| temporal elisa response of rams to brucella ovis following experimental infection or vaccination. | sera from rams vaccinated with antigens extracted chaotropically from brucella ovis by potassium thiocyanate treatment were used to optimise a whole-cell, enzyme-linked immunosorbent assay (celisa) and to monitor the temporal serological response of rams which had been challenged with infected semen by the intranasal or intrapreputial route. three patterns of celisa response were detected. thirteen of 15 rams intranasally challenged did not respond serologically (pattern 1 or nil response). only ... | 1989 | 2922509 |
| isotype profiles induced in balb/c mice during foot and mouth disease (fmd) virus infection or immunization with different fmd vaccine formulations. | the igg isotype response in balb/c mice infected with fmdv or immunized with different vaccine formulations using inactivated virus particles as antigen was analyzed at various times post-inoculation. for this purpose an elisa based on polyclonal antibodies for detection and quantification of mouse igg isotypes with fmd virus (fmdv) specificity was developed. three immunomodulators, which have been shown to be very effective in inducing strong and long-lasting antibody responses (bahnemann, arch ... | 1995 | 7483770 |
| restriction site polymorphism of the genes encoding the major 25 kda and 36 kda outer-membrane proteins of brucella. | seventy-seven brucella reference and field strains from different geographic origins and hosts representing the six recognized species and their different biovars were analysed for diversity of their genes encoding the major 25 and 36 kda outer-membrane proteins (omps) by pcr-rflp. the 25 kda omp is encoded by a single gene (omp25) whereas two closely related genes (omp2a and omp2b) encode and potentially express the 36 kda omp. analysis of pcr products of the omp25 gene digested with nine restr ... | 1995 | 7496522 |
| comparative sensitivity of gel-diffusion and tube agglutination tests for the detection of brucella canis antibodies in experimentally infected dogs. | the microslide gel-diffusion and macro-tube agglutination techniques to detect brucella canis antibodies in dogs were compared. sera from dogs experimentally infected with b. canis and a random sample of dog sera with unknown histories of exposure to this organism were examined. the results of the gel-diffusion method employing specific rough brucella saline-extract antigens of b. canis and brucella ovis were comparable to those obtained by the tube agglutination test. the easily prepared, stabl ... | 1974 | 4210726 |
| identification and characterization of immunodominant antigens during the course of infection with brucella ovis. | the seroresponse against brucella ovis of 8 intrapreputially and 6 intravenously infected rams and 9 ewes infected through mating was analyzed by electrophoretic immunoblotting. additionally, 87 sera from chronically infected rams that were shedding b. ovis in their semen, 226 sera from rams belonging to infected flocks, and 324 sera from false-positive complement fixation test (cft) reactors were examined. in all infected animals, antibody reactivity was predominantly found against 5 b. ovis co ... | 1995 | 7619904 |
| the brucella abortus rb51 vaccine does not confer protection against brucella ovis in rams. | the protective efficacy against brucella ovis of the live vaccine brucella abortus strain rb51 has been evaluated in rams using the attenuated b. melitensis strain rev 1 as a reference vaccine. sixteen brucella-free rams, 6 months of age, were vaccinated subcutaneously with 4.18 x 10(10) c.f.u. rb51. sixteen rams of the same condition and age were vaccinated subcutaneously the same day with 1.1 x 10(9) c.f.u. rev 1. fifteen similar rams were kept unvaccinated as controls. six months after vaccin ... | 1995 | 7631517 |
| studies of antigens for complement fixation and gel diffusion tests in the diagnosis of infections caused by brucella ovis and other brucella. | sonically treated and saline-extracted antigens of brucella ovis, b. canis, b. abortus, and b. melitensis were compared in gel diffusion, complement fixation, and serum absorption tests. all the sonically extracted antigens showed cross-reactions with sera from animals infected or immunized with these species, whereas the saline-extracted antigens were specific for the surface of the rough or smooth colonial phase of the species or strain. the saline-extracted antigens of b. ovis and b. melitens ... | 1972 | 4624210 |
| antibody response to brucella ovis outer membrane proteins in ovine brucellosis. | hot saline extracts of brucella ovis were composed of vesicles with outer membrane proteins (omps), lipopolysaccharide, and phospholipid as constituents. extraction with petroleum ether-chloroform-phenol yielded a protein fraction free of detectable lipopolysaccharide, in which group 3 omps (28,500 apparent molecular weight [28.5k], 27.0k, and 25.5k) represented 81% of the total. group 1 omps and 67.0k, 22.5k to 21.5k, and 19.5k to 18.0k proteins were also detected. adsorption of immune sera wit ... | 1990 | 2298488 |
| differentiation of brucella abortus bv. 1, 2, and 4, brucella melitensis, brucella ovis, and brucella suis bv. 1 by pcr. | several pcr assays which identify the genus brucella but do not discriminate among species have been reported. we describe a pcr assay that comprises five oligonucleotide primers which can identify selected biovars of four species of brucella. individual biovars within a species are not differentiated. the assay can identify three biovars (1, 2, and 4) of b. abortus, all three biovars of b. melitensis, biovar 1 of b. suis, and all b. ovis biovars. these biovars include all of the brucella specie ... | 1994 | 7852552 |
| transmission of brucella ovis by ewes. | | 1994 | 7886906 |
| vaccination with brucella abortus rough mutant rb51 protects balb/c mice against virulent strains of brucella abortus, brucella melitensis, and brucella ovis. | vaccination of balb/c mice with live brucella abortus rb51, a stable rough mutant, produced protection against challenge with virulent strains of brucella abortus, brucella melitensis, and brucella ovis. passive-transfer experiments indicated that vaccinated mice were protected against b. abortus 2308 through cell-mediated immunity, against b. ovis pa through humoral immunity, and against b. melitensis 16m through both forms of immunity. live bacteria were required for the induction of protectiv ... | 1994 | 7927779 |
| [dynamics of igm and igg in rams experimentally infected with brucella ovis]. | | 1973 | 4799562 |
| the bacteriology and serology of ewes inoculated with viable brucella ovis organisms. | | 1970 | 5266508 |
| eradication of brucella ovis from the falkland islands 1977-1993. | a campaign to eradicate brucella ovis from sheep in the falkland islands, using a combination of serological tests and culling, was initiated in 1977 and continued until 1993 when, after a total of 65,266 tests had been carried out, the organism had been eradicated from the national flock. the paper discusses the relative values of the serological tests and suggests guidelines for maintaining the flock free of the infection. | 1994 | 8085323 |
| identification and sequence analysis of is6501, an insertion sequence in brucella spp.: relationship between genomic structure and the number of is6501 copies. | an insertion sequence (is) element of brucella ovis, named is6501, was isolated and its complete nucleotide sequence determined. is6501 is 836 bp in length and occurs 20-35 times in the b. ovis genome and 5-15 times in other brucella species. analysis of the junctions at the sites of insertion revealed a small target site duplication of four bases and inverted repeats of 17 bp with one mismatch. is6501 presents significant similarity (53.4%) with is427 identified in agrobacterium tumefaciens, su ... | 1993 | 8126444 |
| the dangers of disease transmission by artificial insemination and embryo transfer. | this review summarizes the major infectious diseases of the three major agricultural species (cattle, sheep and pigs) and horses, and presents the evidence for and against the possibility of infectious agents being transmitted between animals via the venereal route or by the use of semen or early embryos in commercial artificial insemination (ai) or embryo transfer (et). cattle feature most prominently in the widespread distribution of frozen semen, and national and international organizations h ... | 1993 | 8221041 |
| sequence and characterization of an insertion sequence, is711, from brucella ovis. | the nucleotide (nt) sequence of a previously discovered insertion in brucella ovis was determined and found to have the hallmarks of an insertion sequence (is). the element, designated is711, of 842 bp, is similar in g + c content to that of the brucella genome and is bounded by 20-bp imperfect inverted repeats (ir). the element appears to duplicate the nt ta of a consensus target site, ytar (r, purines; y, pyrimidines). when the complete nt sequence of four elements and 300 bp of the 3' ends of ... | 1993 | 8224885 |
| evaluation of whole cell and subcellular vaccines against brucella ovis in rams. | five antigen preparations from brucella ovis strain reo 198 were incorporated with the pluronic polymer l-121 and muramyl dipeptide and tested as vaccines against b. ovis infection of rams. the antigenic preparations were: (1) a fraction enriched in outer membrane proteins and rough lipopolysaccharide (hot saline extract, hs); (2) the proteins from hs substantially free of lipopolysaccharide; (3) outer membrane blebs; (4) outer membrane-peptidoglycan complexes extracted with detergent; (5) kille ... | 1993 | 8236802 |
| efficacy of brucella suis strain 2 vaccine against brucella ovis in rams. | the protective efficacy against brucella ovis of live vaccine brucella suis strain 2 (s2) and brucella melitensis strain rev 1 has been evaluated in rams. fourteen 4-month-old brucella-free aragonesa rams were vaccinated conjunctivally with 2 x 10(9) c.f.u. s2. sixteen rams of the same breed, condition and age were conjunctivally vaccinated the same day with 1.6 x 10(9) rev 1. thirteen rams were unvaccinated controls. eight months after vaccination all rams were challenged with 6 x 10(9) c.f.u. ... | 1993 | 8296481 |
| avridine and lps from brucella ovis: effect on the memory induced by foot-and-mouth disease virus vaccination in mice. | foot-and-mouth disease is one of the more economically important diseases among meat-producing biungulate species. in contrast to natural infection, current foot-and-mouth disease virus (fmdv) vaccines, prepared with inactivated virus and adjuvants, elicit short-lived protection. the immunomodulating effect on fmdv vaccines of avridine and lipopolysaccharide of brucella ovis (lps) was tested in a murine model. the duration of immunity, protection, stimulation of immunocompetent cells producing a ... | 1993 | 8296482 |
| protective immunity to brucella ovis in balb/c mice following recovery from primary infection or immunization with subcellular vaccines. | experiments were performed with balb/c mice to elucidate the roles of humoral and cell-mediated immune responses in the acquisition of protective immunity to brucella ovis and to compare infection immunity with immunity developed through vaccination with a hot saline extract (hs) of b. ovis. mice convalescing from a primary infection with b. ovis displayed a high level of resistance to reinfection, as evidenced by splenic bacterial counts decreased over 10,000-fold from control groups at 2 weeks ... | 1994 | 8300219 |
| phenotypic comparison of brucella ovis to the dna-homologous brucella species. | | 1969 | 5824903 |
| evaluation of vaccines and of antigen therapy in a mouse model for brucella ovis. | a mouse model was developed to study brucella ovis infection. the evolution of the number of b. ovis per spleen of mice inoculated intravenously, intraperitoneally or subcutaneously was found to be independent of the sex of the mice. the number of b. ovis increased in the spleen when increasing the challenge dose up to 1.7 x 10(7). at higher doses of challenge, the response remained constant. in this model it was observed that the inoculation of brucella melitensis rev 1 vaccine or subcellular b ... | 1993 | 8427038 |
| myofibroblasts and myoepithelial cells in the chicken harderian gland. | an electron microscopic study of the myoepithelial cells in the chicken harderian gland provides evidence that these cells can be transformed into myofibroblasts. after the application of a brucella ovis suspension in sterile saline onto the eyeball, every 5 minutes for half an hour, myoepithelial cells gradually develop over a 90-minute period the characteristic features of myofibroblasts: bundles of intracytoplasmic microfilament; abundant rough endoplasmic reticulum; prominent golgi complex; ... | 1991 | 1810530 |
| demonstration of brucella ovis infection in a bilateral cryptorchid ram. | | 1981 | 6119072 |
| molecular characterization, occurrence, and immunogenicity in infected sheep and cattle of two minor outer membrane proteins of brucella abortus. | screening of a brucella abortus genomic library with two sets of monoclonal antibodies allowed the isolation of the genes corresponding to two minor outer membrane proteins (omp10 and omp19) found in this bacterial species. sequence analysis of the omp10 gene revealed an open reading frame capable of encoding a protein of 126 amino acids. the nucleotide sequence of the insert producing the omp19 protein contains two overlapping open reading frames, the largest of which (177 codons) was shown to ... | 1996 | 8557326 |
| lectin histochemical study on the reproductive tract in normal and brucella ovis-infected rams. | histochemical studies on tissue sections showed alterations of lectin-binding reactivities in the epididymis, seminal vesicle and ampulla of brucella ovis-infected rams. these modifications in the carbohydrate composition of organs participating in maturation, transport, and storage of spermatozoa, could be involved in the impaired fertility observed in this disease. | 1995 | 8593306 |
| nucleotide sequence and expression of the gene encoding the major 25-kilodalton outer membrane protein of brucella ovis: evidence for antigenic shift, compared with other brucella species, due to a deletion in the gene. | the nucleotide sequences encoding the major 25-kda outer membrane protein (omp) (omp25 genes) of brucella ovis 63/290, brucella melitensis 16m, brucella suis 1330, brucella canis rm6/66, and brucella neotomae 5k33 (all reference strains) were determined and compared with that of brucella abortus 544 (p. de wergifosse, p. lintermans, j. n. limet, and a. cloeckaert, j. bacteriol. 177:1911-1914, 1995). the major difference found was between the omp25 gene of b. ovis and those of the other brucella ... | 1996 | 8675306 |
| venereal shedding of ovine lentivirus in infected rams. | to assess shedding of ovine lentivirus (ovlv) in semen of infected rams with or without epididymitis. | 1996 | 8723882 |
| development and validation of an indirect enzyme immunoassay for detection of ovine antibody to brucella ovis. | an indirect enzyme-linked immunosorbent assay (elisa) for the serodiagnosis of brucella ovis infection was developed. the assay uses a mouse monoclonal antibody to bovine igg1 horseradish peroxidase (hrpo) conjugate that cross-reacts with immunoglobulin from sheep and a purified antigen from brucella ovis. the elisa data were read and analyzed according to a targeting procedure. the elisa results were compared with a cold complement fixation test (cft). sera from 675 rams from three uninfected f ... | 1997 | 9100335 |
| periplasmic cyclic 1,2-beta-glucan in brucella spp. is not osmoregulated. | biosynthesis of periplasmic cyclic 1,2-beta-glucans in brucella ovis strain reo198 and b. abortus strain 519 was found to be carried out by membrane-bound enzymes that use udp-glucose (udp-glc) as donor substrate. contrary to what happens in species of the genera agrobacterium and rhizobium, the accumulation of the reaction products in brucella appeared not to be osmotically regulated. incubation of permeabilized cells with udp-[14c]glc led to the formation of soluble neutral cyclic 1,2-beta-glu ... | 1997 | 9141674 |
| antibody and delayed-type hypersensitivity responses to ochrobactrum anthropi cytosolic and outer membrane antigens in infections by smooth and rough brucella spp. | immunological cross-reactions between brucella spp. and ochrobactrum anthropi were investigated in animals and humans naturally infected by brucella spp. and in experimentally infected rams (brucella ovis infected), rabbits (brucella melitensis infected), and mice (b. melitensis and brucella abortus infected). in the animals tested, o. anthropi cytosolic proteins evoked a delayed-type hypersensitivity reaction of a frequency and intensity similar to that observed with b. melitensis brucellin. o. ... | 1997 | 9144364 |
| enzyme-linked immunosorbent assay for brucella ovis specific antibody in ram sera. | an enzyme-linked immunosorbent assay (elisa) for the detection of brucella ovis specific antibody in ram serum was compared with the currently employed complement fixation test (cft). rabbit anti-sheep igg coupled to horseradish peroxidase was used as the antibody-enzyme conjugate and 2,2'-azino-di[3-ethylbenzthiazolin sulphonate (6)] as the substrate. the ratio of the optical density at 414 nm for positive and negative control sera (p/n ratio) was used to optimise the parameters of the test. ra ... | 1984 | 6371959 |
| identification and characterization of brucella ovis immunogenic proteins using two-dimensional electrophoresis and immunoblotting. | in a previous report, proteins from brucella melitensis were characterized by two-dimensional polyacrylamide gel electrophoresis (2-d page) and n-terminal microsequencing. in the present report, we have extended this study to the second etiologic agent in ovine brucellosis, b. ovis, responsible for ram epididymitis and infertility. the combination of 2-d gel electrophoresis and protein microsequencing facilitated the location and identification of the major proteins of b. ovis on the 2-d pattern ... | 1997 | 9298663 |
| histopathology of experimental brucellosis in rams following vaccination with brucella ovis. | lesions induced by inoculation of brucella ovis into the epididymis were compared in rams previously vaccinated with b. ovis bacterin and unvaccinated rams. inoculation of killed b. ovis did not produce significant lesions in either group whereas prior vaccination exacerbated epididymal lesions following inoculation of live b. ovis. increased numbers of neutrophils, macrophages and lymphocytes were present in the interstitium and neutrophilic infiltration of the epididymal duct epithelium and in ... | 1984 | 6529395 |
| dna polymorphism at the omp-31 locus of brucella spp.: evidence for a large deletion in brucella abortus, and other species-specific markers. | the omp-31 gene, encoding a major outer-membrane protein in brucella melitensis, was pcr-amplified from brucella strains representing all species and known biovars by using primers selected according to the b. melitensis 16m omp-31 published sequence. amplification of omp-31 was achieved from dna of all brucella species with the exception of brucella abortus, the only brucella species where expression of omp-31 was not detected by reactivity with an mab specific for an epitope located in omp-31. ... | 1997 | 9308175 |
| [brucella ovis as a possible cause of epididymitis in angora goat rams]. | | 1988 | 3210211 |
| the cellular response of lambs to brucella ovis before and after birth. | the immunological response of lambs to brucella ovis before and after birth was investigated. the establishment of indwelling cannulas in the efferent prescapular lymphatic ducts of foetal lambs allowed continual monitoring of the immune response of a single lymph node. foetal lambs in the last trimester of pregnancy were shown to mount a strong cell-mediated immune response to b. ovis. lymphocytes from the challenged lymph node stimulated with b. ovis in vitro usually first reacted significantl ... | 1997 | 9477485 |
| transposon-derived brucella abortus rough mutants are attenuated and exhibit reduced intracellular survival. | 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 ... | 1998 | 9488389 |
| simultaneous identification of antibodies to brucella abortus and staphylococcus aureus in milk samples by flow cytometry. | two flow cytometric assays are described herein. the single cytometric test (sct) detects antibodies to either brucella abortus or staphylococcus aureus in the serum or milk of a cow or water buffalo. the double cytometric test (dct) detects both anti-b. abortus and anti-s. aureus antibodies concurrently. in the sct, the sample to be tested is incubated in succession with the antigen (either b. abortus or s. aureus) and the proper secondary antiserum (fluorescein isothiocyanate-labelled rabbit a ... | 1998 | 9508316 |
| characterization of an immuno-dominant antigen in brucella ovis and evaluation of its use in an enzyme-linked immunosorbent assay. | a panel of 45 brucella ovis serologically positive sera were tested in immunoblots against b. ovis outer membrane proteins omp31 and omp25, purified by preparative sds-gel electrophoresis. forty-three sera reacted with omp31, while only 11 reacted with omp25, suggesting that omp31 is identical to the previously reported immuno-dominant 29-kda protein. attempts to purify omp31 on a larger scale by using procedures such as ion exchange-, reversed phase-, affinity- and gel filtration chromatography ... | 1998 | 9549861 |
| induction of systemic and mucosal immune responses to human immunodeficiency virus type 1 by a dna vaccine formulated with qs-21 saponin adjuvant via intramuscular and intranasal routes. | induction of mucosal and cell-mediated immunity is critical for development of an effective vaccine against human immunodeficiency virus (hiv). we compared intramuscular and intranasal immunizations with a dna vaccine encoding env of hiv-1 and evaluated the qs-21 saponin adjuvant for augmentation of the systemic and mucosal immune responses to hiv-1 in a murine model. vaccination via the two routes elicited comparable systemic immune responses, and qs-21 consistently enhanced antigen-specific se ... | 1998 | 9573261 |
| epididymitis of rams in the central and southern districts of the orange free state. | scrotal palpation, microscopical examination of semen smears and the application of bacteriological techniques, revealed the incidence of actinobacillus seminis and brucella ovis infection of rams in the central and southern districts of the orange free state to be 2,9% and 4,3%, respectively. more dorper than merino rams were affected. although clinically detectable epididymitis was found in 5,9% of rams examined, infection with a. seminis and b. ovis, as measured by the presence of neutrophils ... | 1984 | 6533305 |
| the regulated outer membrane protein omp21 from comamonas acidovorans is identified as a member of a new family of eight-stranded beta-sheet proteins by its sequence and properties. | omp21, a minor outer membrane protein of the soil bacterium comamonas acidovorans, was purified from a spontaneous mutant lacking a surface layer and long-chain lipopolysaccharide. omp21 synthesis is enhanced by oxygen depletion, and the protein has a variable electrophoretic mobility in sodium dodecyl sulfate-polyacrylamide gel electrophoresis due to its heat-modifiable behavior. the structural gene omp21 encodes a precursor of 204 amino acids with a putative signal peptide of 21 amino acids. m ... | 1998 | 9683466 |
| identification of brucella by ribosomal-spacer-region pcr and differentiation of brucella canis from other brucella spp. pathogenic for humans by carbohydrate profiles. | molecular and chemical characteristics often provide complementary information in the differentiation of closely related organisms. the genus brucella consists of a highly conserved group of organisms. identification of the four species pathogenic in humans (brucella melitensis, brucella abortus, brucella suis, and brucella canis) is problematic for many clinical laboratories that depend primarily on serology and phenotypic characteristics to differentiate species. pcr amplification of the 16s-2 ... | 1998 | 9774568 |
| evaluation of surface components of brucella ovis as antigens for the detection of precipitin antibody in serums from artificially exposed rams. | surface components of brucella ovis obtained by gentle physical shearing were tested as a potentially useful source of reagent for selective serological diagnosis. these antigens were used in a radial immunodiffusion (rid) test against serum from rams which had been inoculated with infective semen containing b. ovis by one of 4 routes namely mating rams with ewes previously inoculated intravaginally with infective semen, or by direct inoculation in the prepuce, rectum or nasal passage. loosely a ... | 1983 | 6651683 |
| effect of p39 gene deletion in live brucella vaccine strains on residual virulence and protective activity in mice. | the 39-kilodalton protein (p39) has previously been shown to be an immunodominant protein in brucella infections. p39 gene deletion mutants of vaccine strains brucella abortus s19 and brucella melitensis rev.1 were constructed by gene replacement. this deletion did not significantly modify the residual virulence of both vaccine strains in cd-1 mice. cd-1 mice vaccinated with the parent or mutant strains were protected against a virulent challenge. mutant vaccine strains devoid of p39 could provi ... | 1998 | 9784574 |
| evaluation of lipopolysaccharides and polysaccharides of different epitopic structures in the indirect enzyme-linked immunosorbent assay for diagnosis of brucellosis in small ruminants and cattle. | brucella abortus and brucella melitensis have surface lipopolysaccharides and polysaccharides carrying b. melitensis-type (m) and b. abortus-type (a) epitopes as well as common (c) epitopes present in all smooth brucella biotypes. crude lipopolysaccharides, hydrolytic o polysaccharides, and native hapten polysaccharides of mc or ac specificity were evaluated in indirect enzyme-linked immunosorbent assays with polyclonal, monoclonal, or protein g conjugates by using sera from cattle, sheep, and g ... | 1998 | 9801329 |
| o-polysaccharide epitopic heterogeneity at the surface of brucella spp. studied by enzyme-linked immunosorbent assay and flow cytometry. | smooth brucella strains are classified into three serotypes, i.e., a+m-, a-m+, and a+m+, according to slide agglutination with a and m monospecific polyclonal sera. the epitopes involved have been located on the o-polysaccharide (o-ps) moiety of the smooth lipopolysaccharide (s-lps), which represents the most exposed antigenic structure on the surface of brucella spp. by use of monoclonal antibodies (mabs) a number of epitope specificities on the o-ps have been reported: a, m, and epitopes share ... | 1998 | 9801349 |
| comparison of polyclonal, monoclonal and protein g peroxidase conjugates in an enzyme-linked immunosorbent assay for the diagnosis of brucella ovis in sheep. | the sensitivities of three commercial peroxidase conjugates (polyclonal anti-sheep igg, recombinant protein g and a monoclonal anti-ruminant igg1) in an enzyme-linked immunosorbent assay for brucella ovis were evaluated. the monoclonal and protein g conjugates reduced, but did not totally remove, the characteristic background reactivity observed with the sera from brucella-free sheep. the protein g conjugate provided the best sensitivity, similar to that obtained with the classical gel diffusion ... | 1998 | 9802197 |
| identification of a 71-kilodalton surface-associated hsp70 homologue in coxiella burnetii. | a coxiella burnetii hsp70 homologue was identified by using an acid activation in vitro system in which protein synthesis has been followed by [35s]methionine labeling, autoradiography, and immunoblotting. the protein was one of those predominantly labeled, and the immunoblots revealed that it was recognized by anti-dnak antibodies. the corresponding gene was isolated, and its nucleotide sequence was determined and analyzed. a single open reading frame (orf) with a size of 1,968 bp was identifie ... | 1998 | 9826369 |
| epidemiological observations in a corriedale flock affected by brucella ovis. | brucellosis in sheep, caused by brucella ovis, is primarily a chronic infectious disease of rams with epididymitis as its most characteristic lesion. six hundred rams from an infected farm were clinically and serologically examined once a year, over a 3-year period. an increase from 2.1% to 6.3% in the prevalence of animals serologically positive to b. ovis occurred over the 3 years. however, the prevalence of rams with lesions in the reproductive tract declined from 14.2% to 6.5% in the third y ... | 1998 | 9868758 |
| discontinuous occurrence of the hsp70 (dnak) gene among archaea and sequence features of hsp70 suggest a novel outlook on phylogenies inferred from this protein. | occurrence of the hsp70 (dnak) gene was investigated in various members of the domain archaea comprising both euryarchaeotes and crenarchaeotes and in the hyperthermophilic bacteria aquifex pyrophilus and thermotoga maritima representing the deepest offshoots in phylogenetic trees of bacterial 16s rrna sequences. the gene was not detected in 8 of 10 archaea examined but was found in a. pyrophilus and t. maritima, from which it was cloned and sequenced. comparative analyses of the hsp70 amino aci ... | 1999 | 9882656 |
| vaccination with live escherichia coli expressing brucella abortus cu/zn superoxide dismutase protects mice against virulent b. abortus. | vaccination of mice with escherichia coli expressing brucella cu/zn superoxide dismutase (sod) [e. coli(pbssod)] induced a significant level of protection against virulent brucella abortus challenge, although this level was not as high as the one reached with b. abortus vaccine strain rb51. in addition, vaccination with e. coli(pbssod) induced antibodies to cu/zn sod and a strong proliferative response of splenocytes when stimulated in vitro with a thioredoxin-cu/zn sod fusion protein. | 1999 | 9916121 |
| cloning and expression of the dnak gene of campylobacter jejuni and antigenicity of heat shock protein 70. | campylobacter jejuni is a leading cause of infectious diarrhea throughout the world. in addition, there is growing evidence that guillain-barré syndrome, an inflammatory demyelinating disease of the peripheral nervous system, is frequently preceded by c. jejuni infection. in the present study, the hrca-grpe-dnak gene cluster of c. jejuni was cloned and sequenced. the dnak gene consists of an open reading frame of 1,869 bp and encodes a protein with a high degree of homology to other bacterial 70 ... | 1999 | 10024560 |
| genomic fingerprinting and development of a dendrogram for brucella spp. isolated from seals, porpoises, and dolphins. | genomic dna from reference strains and biovars of the genus brucella was analyzed using pulsed-field gel electrophoresis (pfge). fingerprints were compared to estimate genetic relatedness among the strains and to obtain information on evolutionary relationships. electrophoresis of dna digested with the restriction endonuclease xbai produced fragment profiles for the reference type strains that distinguished these strains to the level of species. included in this study were strains isolated from ... | 1999 | 10098687 |
| effect of early antibiotic treatment on the antibody response to cytoplasmic proteins of brucella melitensis in mice. | to test whether antibiotic therapy hampers the antibody response to brucella antigens, 30 balb/c mice were infected with brucella melitensis h38 and randomized for treatment with doxycycline administered intraperitoneally for 42 days starting at 7 or 28 days postinfection (p.i.) (groups dox7 and dox28, respectively) or for no treatment (control group). antibodies to smooth lipopolysaccharide (lps) reached peak levels (mean optical density [od] = 2.618) between days 56 and 70 p.i. in the control ... | 1999 | 10225853 |
| molecular characterization of a brucella species large dna fragment deleted in brucella abortus strains: evidence for a locus involved in the synthesis of a polysaccharide. | a brucella melitensis 16m dna fragment of 17,119 bp, which contains a large region deleted in b. abortus strains and dna flanking one side of the deletion, has been characterized. in addition to the previously identified omp31 gene, 14 hypothetical genes have been identified in the b. melitensis fragment, most of them showing homology to genes involved in the synthesis of a polysaccharide. considering that 10 of the 15 genes are missing in b. abortus and that all the polysaccharides described in ... | 1999 | 10338472 |
| cross-reactivity between the rheumatoid arthritis-associated motif eqkraa and structurally related sequences found in proteus mirabilis. | cross-reactivity or molecular mimicry may be one of the underlying mechanisms involved in the etiopathogenesis of rheumatoid arthritis (ra). antiserum against the ra susceptibility sequence eqkraa was shown to bind to a similar peptide esrral present in the hemolysin of the gram-negative bacterium proteus mirabilis, and an anti-esrral serum reacted with eqkraa. there was no reactivity with either anti-eqkraa or anti-esrral to a peptide containing the ederaa sequence which is present in hla-drb1* ... | 1999 | 10338479 |
| experimental brucella ovis infection in pregnant ewes. | forty yearling brucella-free ewes were inoculated with brucella ovis by the conjunctival route in mid or late first pregnancy. only a few ewes excreted b ovis during pregnancy and gave birth to stillborn lambs, but most of them excreted the organism at lambing or during lactation. one of the 11 lambs which were born alive but died before they were weaned was found to be infected postmortem. in contrast, none of the 46 surviving lambs which were reared in isolation until adulthood, was found to b ... | 1999 | 10371013 |
| brucella outer membrane lipoproteins share antigenic determinants with bacteria of the family rhizobiaceae. | brucellae have been reported to be phylogenetically related to bacteria of the family rhizobiaceae. in the present study, we used a panel of monoclonal antibodies (mabs) to brucella outer membrane proteins (omps) to determine the presence of common omp epitopes in some representative bacteria of this family, i.e., ochrobactrum anthropi, phyllobacterium rubiacearum, rhizobium leguminosarum, and agrobacterium tumefaciens, and also in bacteria reported to serologically cross-react with brucella, i. ... | 1999 | 10391877 |
| genetic characterization of a tn5-disrupted glycosyltransferase gene homolog in brucella abortus and its effect on lipopolysaccharide composition and virulence. | we constructed a rough mutant of brucella abortus 2308 by transposon (tn5) mutagenesis. neither whole cells nor extracted lipopolysaccharide (lps) from this mutant, designated ra1, reacted with a brucella o-side-chain-specific monoclonal antibody (mab), bru-38, indicating the absence of o-side-chain synthesis. compositional analyses of lps from strain ra1 showed reduced levels of quinovosamine and mannose relative to the levels in the parental, wild-type strain, 2308. we isolated dna flanking th ... | 1999 | 10417145 |
| epididymitis by brucella ovis: experimental infection in virgin ram lambs. | ten sexually immature rams were experimentally infected with brucella ovis, to verify the antibody kinetics and its localization in urinary and genital tracts. all animals became positive to the complement fixation test from the 2nd post infection (p.i.) week and reached the maximum titre (1:256) on the 4th p.i. week. bacteriemia was demonstrated on 3rd, 4th and 5th p.i. weeks. two animals, respectively slaughtered 11 and 13 weeks after the infection, showed macroscopic and microscopic genital l ... | 1999 | 10423741 |
| outer membrane proteins omp10, omp16, and omp19 of brucella spp. are lipoproteins. | the deduced sequences of the omp10, omp16, and omp19 outer membrane proteins of brucella spp. contain a potential bacterial lipoprotein processing sequence. after extraction with triton x-114, these three proteins partitioned into the detergent phase. processing of the three proteins is inhibited by globomycin, a specific inhibitor of lipoprotein signal peptidase. the three proteins were radioimmunoprecipitated from [(3)h]palmitic acid-labeled brucella abortus lysates with monoclonal antibodies. ... | 1999 | 10456959 |
| identification of an is711 element interrupting the wboa gene of brucella abortus vaccine strain rb51 and a pcr assay to distinguish strain rb51 from other brucella species and strains. | brucella abortus vaccine strain rb51 is a natural stable attenuated rough mutant derived from the virulent strain 2308. the genetic mutations that are responsible for the roughness and the attenuation of strain rb51 have not been identified until now. also, except for an assay based on pulsed-field gel electrophoresis, no other simple method to differentiate strain rb51 from its parent strain 2308 is available. in the present study, we demonstrate that the wboa gene encoding a glycosyltransferas ... | 1999 | 10473532 |
| improvement of the immune response to foot and mouth disease virus vaccine in calves by using avridine as adjuvant. | the epidemiological analysis of the cattle population during the eradication plan of foot and mouth disease (fmd) in argentina clearly indicated a higher incidence of the disease in animals within their first year of age. it is important to improve the efficacy of the vaccination in those animals. in a previous report, we have shown the effect of an immunomodulator, avridine (avr), in the enhancement of the immune response elicited by fmd virus (fmdv) vaccines in experimental hosts [berinstein, ... | 1999 | 10490231 |
| [isolation of brucella ovis from semen of sheep seropositive by elisa and with clinically normal genitals]. | | 1999 | 10509410 |
| protection of mice against brucellosis by vaccination with brucella melitensis wr201(16mdeltapurek). | human brucellosis can be acquired from infected animal tissues by ingestion, inhalation, or contamination of the conjunctiva or traumatized skin by infected animal products. a vaccine to protect humans from occupational exposure or from zoonotic infection in areas where the disease is endemic would reduce an important cause of morbidity worldwide. vaccines currently used in animals are unsuitable for human use. we tested a live, attenuated, purine-auxotrophic mutant strain of brucella melitensis ... | 1999 | 10531243 |
| the outer membrane of brucella ovis shows increased permeability to hydrophobic probes and is more susceptible to cationic peptides than are the outer membranes of mutant rough brucella abortus strains. | the permeability of the outer membrane (om) to hydrophobic probes and its susceptibility to bactericidal cationic peptides were investigated for natural rough brucella ovis and for mutant rough brucella abortus strains. the om of b. ovis displayed an abrupt and faster kinetic profile than rough b. abortus during the uptake of the hydrophobic probe n-phenyl-naphthylamine. b. ovis was more sensitive than rough b. abortus to the action of cationic peptides. bactenecins 5 and 7 induced morphological ... | 1999 | 10531286 |
| complement fixation test to assess humoral immunity in cattle and sheep vaccinated with brucella abortus rb51. | the live attenuated brucella abortus strain rb51 is a rifampin-resistant, lipopolysaccharide (lps) o-chain-deficient mutant of virulent b. abortus 2308. the reduced o-chain content in rb51 prevents this bacterium from inducing antibodies detectable by the conventional serologic tests for bovine brucellosis diagnosis that mainly identify antibodies to lps. the absence of available serologic tests for rb51 also complicates the diagnosis of possible rb51 infections in humans exposed to this strain. ... | 1999 | 10548564 |
| characterization of specific immune responses of mice inoculated with recombinant vaccinia virus expressing an 18-kilodalton outer membrane protein of brucella abortus. | using the shuttle vector pmco2 and the vaccinia virus wild-type wr strain, we constructed a recombinant virus expressing an 18-kda outer membrane protein of brucella abortus. balb/c mice inoculated with this virus produced 18-kda protein-specific antibodies, mostly of immunoglobulin g2a isotype, and in vitro stimulation of splenocytes from these mice with purified maltose binding protein-18-kda protein fusion resulted in lymphocyte proliferation and gamma interferon production. however, these mi ... | 2000 | 10618289 |
| identification of brucella suis genes affecting intracellular survival in an in vitro human macrophage infection model by signature-tagged transposon mutagenesis. | bacteria of the genus brucella are facultative intracellular pathogens which have developed the capacity to survive and multiply in professional and nonprofessional phagocytes. the genetic basis of this aspect of brucella virulence is still poorly understood. to identify new virulence factors, we have adapted signature-tagged transposon mutagenesis, which has been used essentially in animal models, to an in vitro human macrophage infection model. a library of 1,152 brucella suis 1330 tagged mini ... | 2000 | 10678941 |
| molecular characterization of brucella strains isolated from marine mammals. | recently, gram-negative bacteria isolated from a variety of marine mammals have been identified as brucella species by conventional phenotypic analysis. this study found the 16s rrna gene from one representative isolate was identical to the homologous sequences of brucella abortus, b. melitensis, b. canis, and b. suis. is711-based dna fingerprinting of 23 isolates from marine mammals showed all the isolates differed from the classical brucella species. in general, fingerprint patterns grouped by ... | 2000 | 10699036 |
| characterization of heat, oxidative, and acid stress responses in brucella melitensis. | brucella melitensis is a facultative intracellular pathogen which is able to survive and replicate within phagocytic cells. therefore, it has to adapt to a range of different hostile environments. in order to understand the mechanisms of intracellular survival employed by virulent b. melitensis 16m, an initial approach consisting of analysis of the differences in patterns of protein synthesis in response to heat, oxidative, and acid ph stresses by two-dimensional (2-d) polyacrylamide gel electro ... | 2000 | 10768994 |
| brucella abortus and its closest phylogenetic relative, ochrobactrum spp., differ in outer membrane permeability and cationic peptide resistance. | the outer membrane (om) of the intracellular parasite brucella abortus is permeable to hydrophobic probes and resistant to destabilization by polycationic peptides and edta. the significance of these unusual properties was investigated in a comparative study with the opportunistic pathogens of the genus ochrobactrum, the closest known brucella relative. ochrobactrum spp. oms were impermeable to hydrophobic probes and sensitive to polymyxin b but resistant to edta. these properties were traced to ... | 2000 | 10816465 |
| overexpression of protective antigen as a novel approach to enhance vaccine efficacy of brucella abortus strain rb51. | brucella abortus strain rb51 is an attenuated rough strain that is currently being used as the official live vaccine for bovine brucellosis in the united states and several other countries. we reasoned that overexpression of a protective antigen(s) of b. abortus in strain rb51 should enhance its vaccine efficacy. to test this hypothesis, we overexpressed cu/zn superoxide dismutase (sod) protein of b. abortus in strain rb51. this was accomplished by transforming strain rb51 with a broad-host-rang ... | 2000 | 10816475 |
| complementation of brucella abortus rb51 with a functional wboa gene results in o-antigen synthesis and enhanced vaccine efficacy but no change in rough phenotype and attenuation. | brucella abortus rb51 is a stable rough, attenuated mutant vaccine strain derived from the virulent strain 2308. recently, we demonstrated that the wboa gene in rb51 is disrupted by an is711 element (r. vemulapalli, j. r. mcquiston, g. g. schurig, n. srirauganathan, s. m. halling, and s. m. boyle, clin. diagn. lab. immunol. 6:760-764, 1999). disruption of the wboa gene in smooth, virulent b. abortus, brucella melitensis, and brucella suis results in rough, attenuated mutants which fail to produc ... | 2000 | 10858205 |