An aerosolized Brucella spp. challenge model for laboratory animals

To characterize the optimal aerosol dosage of Brucella abortus strain 2308 (S2308) and B. melitensis (S16M) in a laboratory animal model of brucellosis, dosages of 10(3)-10(10) colony forming units (CFU) were nebulized to mice. Although tissue weights were minimally influenced, total CFU per tissues increased beginning at 10(6)-10(7) CFU dosages, with 10(9) CFU appearing to be an optimal dosage for S16M or S2308 aerosol delivery. At 12 weeks after vaccination with 10(7) CFU of B. abortus strain RB51 (SRB51) or saline (control), mice were challenged intraperitoneally (i.p.) (6.4 x 10(4) CFU) or via aerosol (1.76 x 10(9) CFU) with S2308. Mice vaccinated with SRB51 had reduced (P < 0.05) splenic, liver and lung colonization (total CFU and CFU/g) after i.p. challenge with S2308 as compared with control mice after i.p. S2308 challenge. Control and SRB51-vaccinated mice did not differ (P > 0.05) in splenic, liver or lung colonization after aerosol S2308 challenge. Failure to demonstrate vaccine protection was not because of a high aerosol challenge dosage as colonization of spleen and liver tissues was lower (P < 0.05) after aerosol challenge when compared with control mice after i.p. S2308 challenge.     

Differential reactivity of bovine lymphocytes to species of Brucella

The reactivity of bovine lymphocytes to 4 species of Brucella was tested in thymidine-uptake assays, using long-term cultured lymphocytes and freshly obtained blood mononuclear cells. Lymphocytes were taken from cows that had been challenge exposed with a virulent strain of B abortus at midgestation. The cows were classified retrospectively as being naturally resistant or susceptible to brucellosis. Lymphocytes taken from these cows had 3 patterns of reactivity with species of Brucella: pattern 1 was defined by reactivity with 4 species (B abortus, B canis, B suis, and B melitensis); pattern 2 was defined by reactivity with all these species, except B melitensis; pattern 3 was defined by reactivity with B abortus and B canis, but not with B suis or B melitensis. There was a statistically significant correlation between susceptibility to brucellosis and expression of lymphocyte cross-reactivity with B suis (P less than 0.01) and with B melitensis (P less than 0.001).     

Bacteriologic and histologic features in mice after intranasal inoculation of Brucella melitensis

OBJECTIVE: To characterize effects of intranasal inoculation of virulent Brucella melitensis strain 16M in mice. ANIMALS: Female Balb/c mice, 6 to 8 weeks old. PROCEDURE: Studies were designed to elucidate gross morphologic lesions, bacterial burden in target organs, and histologic changes in tissues following experimental intranasal inoculation of mice with B melitensis 16M, which could be used to characterize a model for testing vaccine efficacy. RESULTS: Measurable splenomegaly was evident at 3 and 7 weeks after inoculation. A demonstrable increase in splenic colony-forming units (CFU) from infected mice increased over time with increasing dose when comparing inocula of 10(3), 10(4), and 10(5) CFU. Recovery of brucellae from the lungs was possible early in infection with 10(1), 10(3), and 10(5) CFU, but only the group inoculated with 10(5) CFU consistently yielded quantifiable bacteria. At a dose of 10 CFU, few organisms were located in the spleen. Bacteria were recovered up to 140 days after inoculation in mice given 10(3) CFU. At an inoculum of 10(5) CFU, bacterial counts were highest early in infection. Histologic examination of tissues revealed an increase in white pulp and marginal zone in the spleen and lymphohistiocytic hepatitis. CONCLUSION AND CLINICAL RELEVANCE: Changes in the spleen and liver increased with increases in dose and with increased time following intranasal inoculation with B melitensis 16M. Surprisingly, histologic changes were not observed in the lungs of inoculated mice.     

Brucella species lacking the major outer membrane protein Omp25 are attenuated in mice and protect against Brucella melitensis and Brucella ovis

To aid in the development of novel efficacious vaccines against brucellosis, Omp25 was examined as a potential candidate. To determine the role of Omp25 in virulence, mutants were created with Brucella abortus (BA25), Brucella melitensis (BM25), and Brucella ovis (BO25) which contain disruptions in the omp25 gene (Deltaomp25 mutants). Western immunoblot analysis and PCR verified that the Omp25 protein was not expressed and that the omp25 gene was disrupted in each strain. BALB/c mice infected with B. abortus BA25 or B. melitensis BM25 showed a significant decrease in mean CFU/spleen at 18 and 4 weeks post-infection, respectively, when compared to the virulent parental strain (P<0.05, n=5). Mice infected with B. ovis BO25 had significantly lower mean CFU/spleen counts from 1 to 8 weeks post-infection, at which point the mutant was cleared from the spleens (P<0.01, n=5). Murine vaccination with either BM25 or the current caprine vaccine B. melitensis strain Rev. 1 resulted in more than a 2log(10) reduction in bacterial load following challenge with virulent B. melitensis (P<0.01, n=5). Vaccination of mice with the B. ovis mutant resulted in clearance of the challenge strain and provided 2.5log(10) greater protection against virulent B. ovis than vaccine strain Rev. 1. Based on these data, the B. melitensis and B. ovis Deltaomp25 mutants are interesting vaccine candidates that are currently under study in our laboratory for their safety and efficacy in small ruminants.     

From the discovery of the Malta fever's agent to the discovery of a marine mammal reservoir, brucellosis has continuously been a re-emerging zoonosis

Brucellosis is not a sustainable disease in humans. The source of human infection always resides in domestic or wild animal reservoirs. The routes of infection are multiple: food-borne, occupational or recreational, linked to travel and even to bioterrorism. New Brucella strains or species may emerge and existing Brucella species adapt to changing social, cultural, travel and agricultural environment. Brucella melitensis is the most important zoonotic agent, followed by Brucella abortus and Brucella suis. This correlates with the fact that worldwide, the control of bovine brucellosis (due to B. abortus) has been achieved to a greater extent than the control of sheep and goat brucellosis (due to B. melitensis), these latter species being the most important domestic animals in many developing countries. The long duration and high cost of treatment of human brucellosis reduces the efficacy of the therapy. There is no human vaccine for brucellosis and the occurrence of brucellosis is directly linked to the status of animal brucellosis in a region. In this context, the Word Health Organization has defined the development of a human vaccine, besides the implementation of control and eradication programs in animals, as a high priority. The pathogenicity for humans of B. suis biovars 1, 3 and 4 is well established, whereas B. suis biovar 2 seems to be less pathogenic. Indeed, although hunters and pig farmers have repeatably experienced infectious contact with B. suis biovar 2 (found in wild boar and outdoor-rearing pigs in Europe), isolation of B. suis biovar 2 from human samples have only been seldom reported. Marine mammal brucellosis, due to two new proposed Brucella species i.e. B. cetaceae and B. pinnipediae, represents a new zoonotic threat but the pathogenicity for humans of the different Brucella species found in cetaceans and pinnipeds still has to be clearly established.     

羊布鲁氏菌病及其国内外防控净化措施

布鲁氏菌病(简称"布病")是由布鲁氏菌引起的一种人兽共患传染病.在引起布病的所有布鲁氏菌中,对人和家畜威胁最大的是羊种布鲁氏菌.近年来我国针对布病防控颁布了《国家布鲁氏菌病防治计划(2016-2020年)》等相关文件,但布病尤其是羊布病的发生率仍然处于上升趋势.论文主要介绍国内常用的羊布病的防控方法和策略,并结合国外成...     

Effect of staphylococcal enterotoxin B on cardiorenal functions and survival in X-irradiated rhesus macaques.

Pretreatment of rhesus macaques with nonlethal total-body x-irradiation (400 R) prolonged survival time from an average of 15 hours to 101 hours after intravenous (IV) inoculation of 50 microgram of staphylococcal enterotoxin B (SEB)/kg of body weight. Radiation exposure per se did not produce detectable cardiorenal changes; however, the longer survival after SEB challenge exposure in x-irradiated rhesus macaques was associated with improved cardiorenal functions if compared with that of nonirradiated macaques given the same dose of SEB. Total-body radiation exposure 4 days prior to IV SEB inoculation prevented typical SEB-induced decreases (where measured at 5 hours) in cardiac output, stroke volume, TcH2O, CPAH, Cosm, and urine flow, as well as increases in total peripheral and renal resistance. A theory concerning the significance of radiation-induced leukopenia on modification of SEB-induced cardiorenal functions is postulated.     

Bovine herpesvirus-1 vaccination against experimental bovine herpesvirus-1 and Pasteurella haemolytica respiratory tract infection: onset of protection

The onset of protection offered by intranasal vaccination with attenuated bovine herpesvirus-1 (BHV-1) was studied in 18 calves given a virulent BHV-1 aerosol challenge inoculum and an aerosol challenge exposure to Pasteurella haemolytica. Calves challenge exposed with virus 3, 7, 11, 15, or 19 days after vaccination and challenge exposed 4 days later with Pasteurella haemolytica did not develop viral-bacterial pneumonia, whereas 2 of 3 control calves died of fibrinous bronchopneumonia 40 and 60 hours after the bacterial aerosol and the 3rd control calf had similar lesions. All vaccinated and control calves had detectable amounts of interferon at the time of viral challenge exposure. Protection was observed before detection of neutralizing antibodies to BHV-1 in nasal secretions or in serum. Protection was therefore present from day 3 through day 19 after vaccination, but the mechanism could not be explained completely by neutralizing antibody or interferon.     

Treatment of Brucella melitensis infection in mice by use of liposome-encapsulated gentamicin

Liposomes with entrapped gentamicin were used to treat mice with infection attributable to Brucella melitensis. Liposomes bearing positive charge and formed by egg yolk lecithin, cholesterol, and stearylamine were effective in the elimination of B melitensis residing in liver and spleen. Negatively charged liposomes, formed by egg yolk lecithin, cholesterol, and dicetyl phosphate were also effective in suppression of the infection in liver, but were less so in suppression of the infection in the spleen. Free gentamicin was less effective than the encapsulated antibiotic. At 20 hours after administration of gentamicin encapsulated in liposomes, the gentamicin concentrations in liver and spleen were similar, regardless of the charge of the liposomes--neutral, positive, or negative. However, positively charged liposomes were more efficient than were other liposome types for the treatment of brucellosis caused by B melitensis.     

Effects of allergen challenge on plasma concentrations of prostaglandins, thromboxane B2, and histamine in calves infected with bovine respiratory syncytial virus.

To examine the influence of allergen-induced type-1 hypersensitivity on the pathogenesis of bovine respiratory syncytial virus (BRSV) infection, we sensitized calves by aerosol to Micropolyspora faeni (MF) and challenge exposed them during infection with BRSV. The development of MF-specific IgE serum concentrations was confirmed by ELISA. The dynamics of arachidonic acid metabolism and histamine release during a type-1 hypersensitivity reaction in the bovine lung were studied by quantitating the concentrations of prostaglandin (PG)E2, PGF2 alpha, PGI2 as 6-keto-PGF1 alpha, thromboxane (TX) A2 as TXB2, and histamine in plasma of BRSV-infected and/or MF-sensitized/challenge-exposed calves. Four treatment groups were established: (1) BRSV infection only, (2) aerosol sensitization to MF followed by BRSV infection and aerosol challenge exposure to MF, (3) MF aerosol sensitization and challenge exposure without BRSV infection, and (4) aerosol sensitization to MF followed by BRSV infection without MF challenge exposure. Significantly increased concentrations of PGI2 were associated with MF aerosol exposure, particularly when combined with BRSV infection in group 2. After MF challenge exposure, TXB2 concentrations were significantly greater in the virus and MF challenge-exposed group 2. Individual calf data for the change in MF-specific IgE concentration between the first and second MF challenge exposures and the change in PGE2 concentration 30 minutes after the second MF challenge exposure had a highly significant direct correlation. Histamine concentrations were significantly greater in calves infected with BRSV than in uninfected controls regardless of MF exposure. These data further substantiate the thesis that implicates type-1 hypersensitivity as a pathogenic mechanism in BRSV-related disease.     

Comparison of cardiorenal functions between women and female rhesus macaques.

Selected cardiorenal functions for conscious and chaired rhesus macaques were compared directly and indirectly with corrections for body weights and surface areas to well-established base-line values for human subjects. Certain functional differences between species and conditions of measurement do not allow all experimental results from the rhesus macaque to be extrapolated to man. However, this comparative study provides evidence that can be useful in attempting to evaluate cardiorenal data from macaques in relationship to human studies.     

Flow cytometric characterization of T lymphocyte subsets in the peripheral blood of Chinese rhesus macaques: normal range, age- and sex-related differences

Available data on the normal levels of white blood cell populations in healthy rhesus macaques (Macaca mulatta) originated and living in China is scanty. To obtain such data, blood samples from 150 Chinese rhesus macaques were collected and the normal range of white blood cells and their subsets were analyzed according to age and sex by flow cytometry. CBC data showed that the count of total white blood cells and lymphocytes decreased with age. Phenotypic analysis of CD4 and CD8 expression on CD3+ T lymphocytes showed that the percentage of CD4+ T cells (51.4+/-9.6%), CD4-CD8- T cells (8.5+/-4.1%) and the ratio of CD4+ T to CD8+ T cells (1.26+/-0.55) decreased with age; and the percentage of CD8+ T cells (42.0+/-9.7%), CD4+CD8+ T cells (1.3+/-0.9%) and CD3+ lymphocytes (55.3+/-13.3%) increased with age. However, no statistically significant difference was observed between the male and female groups in most parameters in these monkeys except for the percentage of CD4+CD8+ T cells. This study provided basic information about blood cell count and T lymphocyte subsets in Chinese rhesus macaques. It may be useful for comparative studies using Indian and Chinese rhesus macaques.     

Bovine parainfluenza-3 virus proteins recognized by antibodies of aerosol-exposed calves

Bovine parainfluenza-3 (BPI-3) virus proteins were radiolabeled with [35S]methionine. Control serum containing antibodies to BPI-3 virus obtained from calves that had been immunized by aerosol exposure and by IM inoculation and sera of cattle that were exposed to BPI-3 virus by aerosol only were used to immunoprecipitate BPI-3 virus proteins. The immunoprecipitates were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Viral proteins with estimated molecular weights of 72,000, 70,000, and 58,000 were recognized by the control serum and the sera from calves exposed to BPI-3 virus only by aerosol. These proteins were the hemagglutinin/neuraminidase, nucleoprotein, and fusion protein. The results indicated that a single aerosol exposure to BPI-3 virus induces antibodies to the same BPI-3 virus proteins as do combined aerosol and parenteral inoculations with the virus.     

Apoptosis in T lymphocytes from spleen tissue and peripheral blood of L. (L.) chagasi naturally infected dogs

Dogs are the main domestic reservoirs of L. (L.) chagasi. Once in the vertebrate host, the parasite may cause visceral leishmaniasis, which can also be transmitted to humans. Infected symptomatic dogs show disorganization in the white pulp in spleen tissue and a reduction in T lymphocytes in peripheral blood. To investigate whether apoptosis is involved in white pulp disorganization and diminished T cell counts in peripheral blood, apoptotic T cells from the spleen and peripheral blood of dogs naturally infected with L. (L.) chagasi and presenting clinical manifestations were quantified and compared with healthy dogs. Thirteen symptomatic adult dogs infected by L. (L.) chagasi and six healthy dogs from a nonendemic area (controls) were included in the study. Samples from spleen and peripheral blood were used to quantify apoptosis in CD3 lymphocytes by flow cytometry using Anexin V and Multicaspase kits; the results were compared using the Mann Whitney test. The percentage of total T cells was lower in Leishmania infected dogs compared to healthy controls (P<0.05). Apoptosis levels in T cells from PBMC and spleen were higher in infected dogs than in controls (P<0.05). The least squares method test was used to determine the effect between the degree of structural organization of spleen white pulp and the percentage of apoptosis in the spleen. A significant effect on the level of white pulp morphological disorganization and percentage of apoptosis in spleen T cells was observed (F=20.45; P=0.0014). These data suggest that apoptosis is an important for the immunopathogenesis of canine visceral leishmaniasis.     

RF酰胺相关肽3对大鼠脾脏形态结构及免疫功能的影响

试验旨在探究RF酰胺相关肽3（RFamide-relatedpeptide,RFRP-3）对大鼠脾脏形态结构及免疫功能的影响。试验由两部分组成,一部分选取SD大鼠10只,用于RFRP-3及其G-蛋白偶联受体147（G-protein coupled receptor,GPR147）的分布定位研究;另一部分选取SD大鼠30只,随机分为3组,雌雄各半,分别为对照组（0.9%氯化钠）、RFRP-3低剂量组和高剂量组（1和10 μg/100 μL,共注射200 μL）,连续腹腔注射14 d。采用半定量RT-PCR、Western blotting方法检测大鼠脾脏中RFRP-3及GPR147的表达;运用免疫组织化学的方法确定其分布与定位;大鼠麻醉后心脏采血并分离血清,用抗体芯片检测相关细胞因子的含量;大鼠解剖后取脾脏,测量脾脏长度并计算脾脏指数;采用HE染色方法检测腹腔注射RFRP-3对脾脏形态学变化的影响;采用实时荧光定量PCR检测脾脏中IL-1β和TNF-α mRNA的表达。结果表明,RFRP-3 mRNA在SD大鼠脾脏中无表达,GPR147 mRNA呈中等程度表达。Western blotting结果显示,在SD大鼠脾脏中均有RFRP-3及其受体GPR147的表达;RFRP-3主要分布于脾脏的红髓,GPR147主要分布于白髓;腹腔注射不同浓度的RFRP-3均可使血清IL-1α、IL-1β、TNF-α及MCP-1升高,脾脏长度增加、脾脏指数升高。HE染色结果显示,脾脏白髓面积增大、脾小结增多;红髓内脾索增粗、红细胞明显增多。实时荧光定量PCR结果显示,脾脏中IL-1β和TNF-α mRNA表达量极显著或显著升高（P<0.01;P<0.05）。上述结果表明,RFRP-3可能通过旁分泌方式到达大鼠脾脏上的GPR147受体进而发挥其增强脾脏免疫功能的作用。     

Age Difference in Morphology and Immunohistology inthe Thymus and Spleen in Crl:CD (SD) Rats

We investigated chronological changes in immunohistochemical phenotyping in the thymus and spleen in Crl:CD rats up to the age of about one year. In the thymus, T cells increased markedly from 3 to 4 weeks of age. Proliferating cells also increased markedly at these points. B cells tended towards an increase with age. In the spleen, white pulp increased until 9 weeks of age and remained fairly stable thereafter. In the periarteriolar lymphoid sheath and marginal zone, T cells gradually increased until 9 weeks of age and became almost flat thereafter. In the lymph follicle, T cells increased with age. B cells tended towards an increase with age in all areas of the spleen. It was concluded that development of the thymus was most marked from 3 to 4 weeks of age and that both the thymus and spleen had matured by 9 weeks of age.     

A review of camel brucellosis

We reviewed the literature on camel brucellosis. The seroprevalence of brucellosis in camels appears to follow two distinct patterns: a low (2-5%) prevalence in nomadic or extensively kept camels and a high (8-15%) prevalence in camels kept intensively or semi-intensively. The infection is caused by different biotypes of Brucella abortus and Brucella melitensis. Many gaps exist in the literature on the epidemiology of camel brucellosis. There is no clear policy in any of the camel-keeping countries regarding the control of brucellosis in camels. We suggest whole-herd vaccination in low-prevalence countries and test-and-slaughter followed by vaccination in high-prevalence countries.     

Brucellosis in camels

Camels are highly susceptible to brucellosis caused by Brucella melitensis and Brucella abortus. Difficulties can arise in diagnosis of camel brucellosis, especially as this disease provokes only few clinical signs in contrast to its clinical course in cattle. Because none of the commonly used serological test can be perceived as a perfect test for Brucella diagnosis in camel and most serological tests used for camels have been directly transposed from cattle without adequate validation, an incorrect diagnosis may occur when diagnosis is based on serology alone. Of imminent concern is the fact that brucellosis can be easily transmitted from animals or their products to humans mainly via milk. In many developing countries in the arid areas of Asia and Africa, camels are still the most important productive livestock for nomadic populations. Therefore, we reviewed the literatures on camel brucellosis to highlight the epidemiologic, economic and public health impact of camel brucellosis as a basis for designing effective control strategies.     

Brucella abortus is Prevalent in Both Humans and Animals in Bangladesh

To determine the role of different Brucella (B.) spp. in Bangladesh, 62 animal samples and 500 human sera were tested. Animal samples from cattle, goats and sheep (including milk, bull semen, vaginal swabs and placentas) were cultured for Brucella spp. Three test‐positive human sera and all animal samples were screened by Brucella genus‐specific real‐time PCR (RT‐PCR), and positive samples were then tested by IS711 RT‐PCR to detect B. abortus and B. melitensis DNA. Only B. abortus DNA was amplified from 13 human and six animal samples. This is the first report describing B. abortus as the aetiological agent of brucellosis in occupationally exposed humans in Bangladesh. Of note is failure to detect B. melitensis DNA, the species most often associated with human brucellosis worldwide. Further studies are required to explore the occurrence of Brucella melitensis in Bangladesh.     

镰刀菌毒素对断奶仔猪脾脏抗氧化能力和白细胞介素-1β、白细胞介素-6分布和表达的影响

本试验旨在研究自然霉变饲粮中镰刀菌毒素对断奶仔猪脾脏抗氧化能力和白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)分布和表达的影响。选择35日龄平均体重为(8.45±0.94)kg的健康三元杂交(杜×长×大)断奶仔猪母猪40头,随机分为2组,每组20头。对照组饲喂基础饲粮,镰刀菌毒素组饲喂含镰刀菌毒素[玉米赤霉烯酮(ZEN)0.90 mg/kg;呕吐毒素(DON)1.43mg/kg,烟曲霉毒素(FUM)5.85 mg/kg]的试验饲粮。预试期7d,正试期35d。结果表明:1)与对照组相比,镰刀菌毒素显著降低了断奶仔猪血清和脾脏谷胱甘肽过氧化物酶(GSH-Px)和总超氧化物歧化酶(T-SOD)活性(P0.05),显著升高了丙二醛(MDA)含量(P0.05)。2)镰刀菌毒素使断奶仔猪脾脏白髓区明显变小,红髓区扩张且出现近圆形小空洞,动脉周围淋巴鞘中淋巴细胞数量较少。3)镰刀菌毒素导致断奶仔猪脾脏IL-1β和IL-6阳性细胞主要集中于白髓边缘,且靠近血窦的地方阳性点更多。4)与对照组相比,镰刀菌毒素显著升高了断奶仔猪脾脏IL-1β和IL-6mRNA相对表达量(P0.05)。由此可见,饲粮中镰刀菌毒素显著影响断奶仔猪血清和脾脏抗氧化能力,并通过改变脾脏IL-1β和IL-6的分布和表达,降低脾脏的免疫功能。