Immuno-pathophysiological responses of mouse model to experimental infection with Brucella melitensis and its lipopolysaccharides via intraperitoneal route

ABSTRACT Research for novel Brucella vaccines has focused upon the development of live vaccine strains, which have proven more efficacious than killed or subunit vaccines. In an effort to develop improved vaccines, signature-tagged mutant banks were screened to identify mutants attenuated for survival. Mutants selected from these screens exhibited various degrees of attenuation characterized by the rate of clearance, ranging from a failure to grow in macrophages after 24 h of infection to a failure to persist in the mouse model beyond 8 weeks. Ideal vaccine candidates should be safe to the host, while evoking protective immunity. In the present work, we constructed unmarked deletion mutants of three gene candidates, manBA, virB2, and asp24, in both Brucella abortus and Brucella melitensis. The Δasp24 mutants, which persist for extended periods in vivo, are superior to current vaccine strains and to other deletion strains tested in the mouse model against homologous challenge infection after 12, 16, and 20 weeks postvaccination. The Δasp24 mutants also display superior protection compared to ΔmanBA and ΔvirB2 mutants against heterologous challenge in mice. From this study, a direct association between protection against infection and cytokine response was not apparent between all vaccine groups and, therefore, correlates of protective immunity will need to be considered further. A distinct correlation between persistence of the vaccine strain and protection against infection was corroborated.

Download Full-text

Yellow Fever Virus/Dengue-2 Virus and Yellow Fever Virus/Dengue-4 Virus Chimeras: Biological Characterization, Immunogenicity, and Protection against Dengue Encephalitis in the Mouse Model

Journal of Virology ◽

10.1128/jvi.77.6.3655-3668.2003 ◽

2003 ◽

Vol 77 (6) ◽

pp. 3655-3668 ◽

Cited By ~ 33

Author(s):

Thomas J. Chambers ◽

Yan Liang ◽

Deborah A. Droll ◽

Jacob J. Schlesinger ◽

Andrew D. Davidson ◽

...

Keyword(s):

Mouse Model ◽

Dengue Virus ◽

Yellow Fever ◽

Yellow Fever Virus ◽

Fever Virus ◽

E Proteins ◽

Dengue Viruses ◽

Intracerebral Inoculation ◽

Intraperitoneal Route ◽

Chimeric Viruses

ABSTRACT Two yellow fever virus (YFV)/dengue virus chimeras which encode the prM and E proteins of either dengue virus serotype 2 (dengue-2 virus) or dengue-4 virus within the genome of the YFV 17D strain (YF5.2iv infectious clone) were constructed and characterized for their properties in cell culture and as experimental vaccines in mice. The prM and E proteins appeared to be properly processed and glycosylated, and in plaque reduction neutralization tests and other assays of antigenic specificity, the E proteins exhibited profiles which resembled those of the homologous dengue virus serotypes. Both chimeric viruses replicated in cell lines of vertebrate and mosquito origin to levels comparable to those of homologous dengue viruses but less efficiently than the YF5.2iv parent. YFV/dengue-4 virus, but not YFV/dengue-2 virus, was neurovirulent for 3-week-old mice by intracerebral inoculation; however, both viruses were attenuated when administered by the intraperitoneal route in mice of that age. Single-dose inoculation of either chimeric virus at a dose of 105 PFU by the intraperitoneal route induced detectable levels of neutralizing antibodies against the homologous dengue virus strains. Mice which had been immunized in this manner were fully protected from challenge with homologous neurovirulent dengue viruses by intracerebral inoculation compared to unimmunized mice. Protection was associated with significant increases in geometric mean titers of neutralizing antibody compared to those for unimmunized mice. These data indicate that YFV/dengue virus chimeras elicit antibodies which represent protective memory responses in the mouse model of dengue encephalitis. The levels of neurovirulence and immunogenicity of the chimeric viruses in mice correlate with the degree of adaptation of the dengue virus strain to mice. This study supports ongoing investigations concerning the use of this technology for development of a live attenuated viral vaccine against dengue viruses.

Download Full-text

Efficacy of several antibiotic combinations against Brucella melitensis Rev 1 experimental infection in BALB/c mice

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkl289 ◽

2006 ◽

Vol 58 (3) ◽

pp. 622-626 ◽

Cited By ~ 12

Author(s):

M. J. Grillo

Keyword(s):

Experimental Infection ◽

Brucella Melitensis

Download Full-text

Hysterothylacium amoyense in Platycephalous indicus: a Persian Gulf fish and its experimental infection of mouse model

Comparative Clinical Pathology ◽

10.1007/s00580-016-2318-x ◽

2016 ◽

Vol 25 (6) ◽

pp. 1143-1149 ◽

Cited By ~ 2

Author(s):

Mohsen Najjari ◽

Seyed Mahmoud Sadjjadi ◽

Amin Derakhshanfar ◽

Mohammad Ebrahimipour

Keyword(s):

Mouse Model ◽

Experimental Infection ◽

Persian Gulf

Download Full-text

Extended Safety and Efficacy Studies of the Attenuated Brucella Vaccine Candidates 16MΔvjbRand S19ΔvjbRin the Immunocompromised IRF-1−/−Mouse Model

Clinical and Vaccine Immunology ◽

10.1128/cvi.05321-11 ◽

2011 ◽

Vol 19 (2) ◽

pp. 249-260 ◽

Cited By ~ 9

Author(s):

A. M. Arenas-Gamboa ◽

A. C. Rice-Ficht ◽

Y. Fan ◽

M. M. Kahl-McDonagh ◽

T. A. Ficht

Keyword(s):

Mouse Model ◽

Brucella Melitensis ◽

Protective Efficacy ◽

Pathological Changes ◽

Wild Type ◽

Live Attenuated Vaccine ◽

Content Type ◽

Vaccine Candidates ◽

Multiple Organs ◽

Efficacious Vaccine

ABSTRACTThe global distribution of brucellosis and high incidence in certain areas of the world warrant the development of a safer and efficacious vaccine. For the past 10 years, we have focused our attention on the development of a safer, but still highly protective, live attenuated vaccine for human and animal use. We have demonstrated the safety and protective efficacy of the vaccine candidates 16MΔvjbRand S19ΔvjbRagainst homologous and heterologous challenge in multiple immunocompetent animal models, including mice and deer. In the present study, we conducted a series of experiments to determine the safety of the vaccine candidates in interferon regulatory factor-1-knockout (IRF-1−/−) mice. IRF-1−/−mice infected with either wild-typeBrucella melitensis16M or the vaccine strainBrucella abortusS19 succumb to the disease within the first 3 weeks of infection, which is characterized by a marked granulomatous and neutrophilic inflammatory response that principally targets the spleen and liver. In contrast, IRF-1−/−mice inoculated with either the 16MΔvjbRor S19ΔvjbRvaccine do not show any clinical or major pathological changes associated with vaccination. Additionally, when 16MΔvjbR- or S19ΔvjbR-vaccinated mice are challenged with wild-typeBrucella melitensis16M, the degree of colonization in multiple organs, along with associated pathological changes, is significantly reduced. These findings not only demonstrate the safety and protective efficacy of thevjbRmutant in an immunocompromised mouse model but also suggest the participation of lesser-known mechanisms in protective immunity against brucellosis.

Download Full-text

A Brucella melitensis high temperature requirement A (htrA) deletion mutant demonstrates a stress response defective phenotype in vitro and transient attenuation in the BALB/c mouse model

Microbial Pathogenesis ◽

10.1016/s0882-4010(96)80001-5 ◽

1995 ◽

Vol 19 (5) ◽

pp. 277-284 ◽

Cited By ~ 15

Author(s):

Robert W. Phillips ◽

Philip H. Elzer ◽

R. Martin Roop

Keyword(s):

High Temperature ◽

Stress Response ◽

Mouse Model ◽

Deletion Mutant ◽

Brucella Melitensis ◽

Temperature Requirement

Download Full-text

Characterization of a novel intratracheal aerosol challenge model of Brucella melitensis in guinea pigs

10.1101/457184 ◽

2018 ◽

Author(s):

M.E. Hensel ◽

D.G. Garcia-Gonzalez ◽

S.P. Chaki ◽

J. Samuel ◽

A.M. Arenas-Gamboa

Keyword(s):

Animal Model ◽

Mouse Model ◽

Guinea Pig ◽

Lymph Nodes ◽

Guinea Pigs ◽

Brucella Melitensis ◽

Recurrent Fever ◽

Human Brucellosis ◽

High Dose ◽

Post Inoculation

AbstractB. melitensis is considered the most virulent of the Brucella species, and a need exists for an improved laboratory animal model of infection that mimics natural transmission and disease. Guinea pigs are highly susceptible to infection with Brucella spp. and develop a disease syndrome that mimics natural disease after aerosol inoculation. Intratracheal inoculation is a targeted means of generating aerosols that offer advantages over aerosol chamber delivery. To establish this delivery method, female, Hartley guinea pigs were infected via intratracheal inoculation with PBS or 16M B. melitensis at low dose (101 to 103) or high dose (106 to 108) and monitored for 30 days for signs of disease. Guinea pigs in the high dose groups developed fever between 12-17 days post-inoculation. Bacteria were recovered from the spleen, liver, lymph nodes, lung, and uterus at 30-days post-inoculation and demonstrated dose dependent mean increases in colonization and pathologic changes consistent with human brucellosis. To study the kinetics of extrapulmonary dissemination, guinea pigs were inoculated with 107 CFU and euthanized at 2-hours post inoculation and at weekly intervals for 3 weeks. 5.8×105 to 4.2×106 CFU were recovered from the lung 2 hours post-inoculation indicating intratracheal inoculation is an efficient means of infecting guinea pigs. Starting at 1-week post inoculation bacteria were recovered from the aforementioned organs with time dependent mean increases in colonization. This data demonstrates that guinea pigs develop a disease syndrome that models the human manifestation of brucellosis, which makes the guinea pig a valuable model for pathogenesis studies.Author summaryBrucellosis is caused by a gram-negative, intracellular bacterial pathogen with a worldwide distribution and affects up to half a million people per year. It is a neglected zoonosis that impacts not only animal welfare, but also exert economic pressure on afflicted individuals through loss of wages and decreased productivity. In people, recurrent fever, malaise, and anorexia accompanied by enlargement of the spleen and lymph nodes are common clinical symptoms of infection. The mouse model has been used extensively to study the pathogenesis of brucellosis, but there are drawbacks to extrapolating studies in mice to develop vaccines or therapeutics for people. Mice are frequently inoculated via intraperitoneal injection, which is an artificial means of producing disease that does not mimic natural transmission or disease features, such as fever. An animal model is needed that can be infected through natural transmission routes and subsequently develop a syndrome that matches clinical disease seen in people in order to study the pathogenesis of disease and to develop vaccines and therapeutics. The guinea pig offers an improvement on the mouse model because it can be infected via aerosol inoculation and develops fever, a humoral immune response, systemic colonization, and macroscopic and microscopic lesions of disease. As such, guinea pigs could be used a more biologically relevant model for evaluation of host-pathogen interactions.

Download Full-text