scholarly journals Pathogenesis and Animal Models of Post-Primary (Bronchogenic) Tuberculosis, A Review

Pathogens ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 19 ◽  
Author(s):  
Robert Hunter ◽  
Jefrey Actor ◽  
Shen-An Hwang ◽  
Arshad Khan ◽  
Michael Urbanowski ◽  
...  

Primary and post-primary tuberculosis (TB) are different diseases caused by the same organism. Primary TB produces systemic immunity. Post-primary TB produces cavities to support massive proliferation of organisms for transmission of infection to new hosts from a person with sufficient immunity to prevent systemic infection. Post-primary, also known as bronchogenic, TB begins in humans as asymptomatic bronchial spread of obstructive lobular pneumonia, not as expanding granulomas. Most lesions regress spontaneously. However, some undergo caseation necrosis that is coughed out through the necrotic bronchi to form cavities. Caseous pneumonia that is not expelled through the bronchi is retained to become the focus of fibrocaseous disease. No animal reproduces this entire process. However, it appears that many mammals utilize similar mechanisms, but fail to coordinate them as do humans. Understanding this makes it possible to use human tuberculous lung sections to guide manipulation of animals to produce models of particular human lesions. For example, slowly progressive and reactivation TB in mice resemble developing human bronchogenic TB. Similarly, bronchogenic TB and cavities resembling those in humans can be induced by bronchial infection of sensitized rabbits. Granulomas in guinea pigs have characteristics of both primary and post primary TB. Mice can be induced to produce a spectrum of human like caseating granulomas. There is evidence that primates can develop bronchogenic TB. We are optimistic that such models developed by coordinated study of human and animal tissues can be used with modern technologies to finally address long-standing questions about host/parasite relationships in TB, and support development of targeted therapeutics and vaccines.

Author(s):  
Bhong Prabha N. ◽  
Naikawade Nilofar. S. ◽  
Mali Pratibha. R. ◽  
Bindu Madhavi. S.

Objectives: The present study designed to evaluate the Antiasthmatic activity of aqueous extract of bark of Eugenia Jambolana (AEEJ) on in vitro and in vivo animal models. Materials and methods: Different in vitro and in vivo animal models was used to study the anti asthmatic activity as isolated goat tracheal chain preparation, Acetylcholine and Histamine induced bronconstriction in guinea pigs, effect of drug extract on histamine release from mast cell was checked by clonidine-induced mast cell degranulation, and milk-induced eosinophilia and leukocytosis. Results: In-vitro study on goat tracheal chain preparation revealed that aqueous extract of Eugenia jambolana (AEEJ)bark exerted antagonistic effect on the histamine induced contraction. (P<0.05) The guinea pigs when exposed to 0.2% histamine aerosol showed signs of progressive dyspnoea leading to convulsions. AEEJ significantly prolonged the latent period of convulsions (PCT) as compared to control following the exposure of histamine (0.2%) aerosol (P<0.01). The observation of present study indicates aqueous extract of Eugenia jambolana shows significant inhibition of milk induced eosinophilia and leukocytosis. Group of animals pretreated with aqueous Eugenia jambolana bark extract showed significant reduction in degranulation of mast cells when challenged with clonidine. The prevention of degranulation process by the aqueous Eugenia jambolana bark extract (P<0.01) indicates a possible stabilizing effect on the mast cells, indicating mast cell stabilizing activity. Conclusions: Thus, AEEJ showed antihistaminic, mast cell stabilizing and protective in guinea pigs against histamine induced PCD, reduced eosinophilia and leukocytosis and hence possesses potential role in the treatment of asthma.


2012 ◽  
Vol 80 (8) ◽  
pp. 2623-2631 ◽  
Author(s):  
Haim Levy ◽  
Shay Weiss ◽  
Zeev Altboum ◽  
Josef Schlomovitz ◽  
Itai Glinert ◽  
...  

ABSTRACTThe virulence ofBacillus anthracis, the causative agent of anthrax, stems from its antiphagocytic capsule, encoded by pXO2, and the tripartite toxins encoded by pXO1. The accepted paradigm states that anthrax is both an invasive and toxinogenic disease and that the toxins play major roles in pathogenicity. We tested this assumption by a systematic study of mutants with combined deletions of thepag,lef, andcyagenes, encoding protective antigen (PA), lethal factor (LF), and edema factor (EF), respectively. The resulting seven mutants (single, double, and triple) were evaluated following subcutaneous (s.c.) and intranasal (i.n.) inoculation in rabbits and guinea pigs. In the rabbit model, virulence is completely dependent on the presence of PA. Any mutant bearing apagdeletion behaved like a pXO1-cured mutant, exhibiting complete loss of virulence with attenuation indices of over 2,500,000 or 1,250 in the s.c. or i.n. route of infection, respectively. In marked contrast, in guinea pigs, deletion ofpagor even of all three toxin components resulted in relatively moderate attenuation, whereas the pXO1-cured bacteria showed complete attenuation. The results indicate that a pXO1-encoded factor(s), other than the toxins, has a major contribution to the virulence mechanism ofB. anthracisin the guinea pig model. These unexpected toxin-dependent and toxin-independent manifestations of pathogenicity in different animal models emphasize the importance and need for a comprehensive evaluation ofB. anthracisvirulence in general and in particular for the design of relevant next-generation anthrax vaccines.


2019 ◽  
Vol 87 (12) ◽  
Author(s):  
A. E. Gregory ◽  
E. J. van Schaik ◽  
K. E. Russell-Lodrigue ◽  
A. P. Fratzke ◽  
J. E. Samuel

ABSTRACT Coxiella burnetii, the etiological agent of Q fever, is a Gram-negative bacterium transmitted to humans by inhalation of contaminated aerosols. Acute Q fever is often self-limiting, presenting as a febrile illness that can result in atypical pneumonia. In some cases, Q fever becomes chronic, leading to endocarditis that can be life threatening. The formalin-inactivated whole-cell vaccine (WCV) confers long-term protection but has significant side effects when administered to presensitized individuals. Designing new vaccines against C. burnetii remains a challenge and requires the use of clinically relevant modes of transmission in appropriate animal models. We have developed a safe and reproducible C. burnetii aerosol challenge in three different animal models to evaluate the effects of pulmonary acquired infection. Using a MicroSprayer aerosolizer, BL/6 mice and Hartley guinea pigs were infected intratracheally with C. burnetii Nine Mile phase I (NMI) and demonstrated susceptibility as determined by measuring bacterial growth in the lungs and subsequent dissemination to the spleen. Histological analysis of lung tissue showed significant pathology associated with disease, which was more severe in guinea pigs. Infection using large-particle aerosol (LPA) delivery was further confirmed in nonhuman primates, which developed fever and pneumonia. We also demonstrate that vaccinating mice and guinea pigs with WCV prior to LPA challenge is capable of eliciting protective immunity that significantly reduces splenomegaly and the bacterial burden in spleen and lung tissues. These data suggest that these models can have appreciable value in using the LPA delivery system to study pulmonary Q fever pathogenesis as well as designing vaccine countermeasures to C. burnetii aerosol transmission.


2016 ◽  
Vol 45 (3) ◽  
pp. 435-439
Author(s):  
Alexandria M. Schauer ◽  
Adrienne Schucker ◽  
Cathy S. Carlson

Hartley guinea pigs are widely used animal models of disease, particularly in studies of osteoarthritis. The purpose of this study was to investigate lesions in the costal cartilage from 16 male, 5- to 6-month-old Hartley guinea pigs. Routine histological sections from the costal cartilage and costochondral junction (longitudinal and cross sections) and sternum (for evaluation of bone marrow) were examined. All 16 (100%) animals had histological lesions involving the costal cartilage that included matrix degeneration and mineralization, reduced cellularity, and evidence of chondrocyte necrosis. Of the 16, 4 (25%) of the lesions contained blood vessels and 3 (19%) contained central osseous metaplasia. The cartilage lesions were accompanied by degeneration (sometimes with regeneration and/or fibrosis) in adjacent skeletal muscle in 15 of the 16 (94%) animals. The lesions in the costal cartilage were interpreted as dystrophic mineralization of unknown cause and appear to be incidental findings, although they bear some resemblance to lesions occurring in Tietze’s disease in humans. The significance of the lesions in skeletal muscle is unclear. Histological lesions of cartilage matrix degeneration and mineralization in these sites have not, to our knowledge, been reported previously.


Vaccines ◽  
2013 ◽  
Vol 1 (3) ◽  
pp. 305-327 ◽  
Author(s):  
Marie Borggren ◽  
Lasse Vinner ◽  
Betina Andresen ◽  
Berit Grevstad ◽  
Johanna Repits ◽  
...  

1955 ◽  
Vol 1 (8) ◽  
pp. 622-633
Author(s):  
László Kátó ◽  
Béla Gözsy

The outcome of experimental tuberculosis in guinea pigs was favorably influenced by treatment with 1,4-dimethyl-7-isopropylazulene. This compound had no antituberculous properties in vitro, but stimulates phagocytic activity of cells of the reticulo-endothelial system. Effects of simultaneous treatment with the azulene derivative and dihydrostreptomycin on well-established tuberculosis were similarly studied. Therapeutical effect of dihydrostreptomycin was significantly increased by the simultaneous treatment with the azulene. This experiment brought evidence that the host–parasite relationship in experimental tuberculosis can be favorably influenced for the benefit of the host by appropriate treatment acting against the parasite and simultaneously stimulating the defense mechanism of the host. The authors discuss the need for more research in tuberculosis therapy directed toward finding ways of stimulating the cell-linked defense mechanism of the host against bacterial invaders.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
María V. Bianco ◽  
Simon Clark ◽  
Federico C. Blanco ◽  
Sergio Garbaccio ◽  
Elizabeth García ◽  
...  

AMycobacterium bovisknockout inp27-p55operon was tested as an antituberculosis experimental vaccine in animal models. The mutant MbΔp27-p55 was significantly more attenuated in nude mice than its parental strain but more virulent than BCG Pasteur. Challenge experiments in mice and guinea pigs usingM. bovisorM. tuberculosisstrains showed similar protection conferred by MbΔp27-p55 mutant than BCG in terms of pathology and bacterial loads in spleen but lower protection than BCG in lungs. When tested in cattle, MbΔp27-p55 did not induce IL-2 expression and induced a very low production of IFNγ, suggesting that the lack of P27/P55 reduces the capacity ofM. bovisof triggering an adequate Th1 response.


2020 ◽  
Author(s):  
AA Korenkova ◽  
VV Bahmetjev ◽  
KS Gorbunov

Some human coronaviruses that share genetic similarity are known to infect other mammals. A host can harbor several coronaviruses, which creates favorable conditions for recombination and eventually results in the emergence of new viral strains and species. This review looks at SARS-CoV-2 in the context of other coronaviruses and their evolution, with a special focus on possible host jumps and adaptation of the virus to its new hosts. To understand these phenomena, it is essential to know the ecological relationships between the host and other organisms. Candidate COVID-19 models are not limited to the organisms and laboratory animals previously used to study SARS and MERS. The diversity of SARS-CoV-2 hosts suggests there is a wide range of candidate animal models for studying COVID-19 that might be suitable for testing drugs and vaccines against this infection. Considering the diversity of coronaviruses, integrated medical, veterinarian and zoological studies might help to speed up the development of tools for combating coronaviral infections and prevent future epidemics.


2018 ◽  
Author(s):  
Alejandro L. Antonia ◽  
Liuyang Wang ◽  
Dennis C. Ko

AbstractEukaryotic parasites in the genusLeishmaniaplace approximately 350 million people per year at risk of disease. In addition to their global health significance,Leishmaniaspp. have served as an important model for delineating basic concepts in immunology such as T-helper cell polarization. There have been many qPCR based assays reported for measuring parasite burden in humans and animals. However, these are largely optimized for use in clinical diagnosis and not specifically for animal models. This has led several of these assays to have suboptimal characteristics for use in animal models. For example, multi-copy number genes have been frequently used to increase sensitivity, but are subject to greater plasticity within the genome and thus may confound effects of experimental manipulations in animal models. In this study, we develop a sybr-green based quantitative touchdown PCR assay for a highly conserved and single copy, putative RNA binding protein, DRBD3. With primers nearly perfectly conserved across allLeishmaniaspp., this assay rivals the sensitivity of previously reported qPCR based methods of parasite quantitation and successfully detectedL. majorfrom mouse infection. Use of this protocol in the future will lead to improved accuracy in animal based models and help to tease apart differences in biology of host-parasite interactions.


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