• Parasites, Hosts and Diseases
• /
• v.36 no.1
• /
• pp.23-32
• /
• 1998

The pathogenic potential of Acnnthamoebc strains was evaluated by experimental infection of murine AIDS (MAIDS) model. C57BL/6 mice were induced to immunocompromized state by intraperitoneal injection of LP-BM5 MuLV and revealed the typical splenomegalty and Iymphatic enlargement of axillar and inguinal regios on necropsy 4 weeks after viral infection. Although there was no significant difference in the mortality rate of MAIDS mouse according to the culture temperature, it was very different in the mortality rate from strain to strain of Accnthnmoebc. A. henIHi OC-3A strain isolated from the brain of a GAE patient showed !he highest mortality rate and A. culbertsoni A-1 strain from tissue culture was the second. KA/S3 and KA/S2 strains isolated from soil revealed very low virulence. The mice infected by intranasal inoculation of Acanthnmoebc showed relatively chronic course than intravenous inoculation. The gross findings of lungs and brains from infected mice were variable among mice. On the microscopic observations, the lungs showed much more severe inflammation and necrosis than the brains microscopically. This MAIDS model would be useful to study the opportunistic protozoan infections of AIDS patients. In the light of these results. the pathogenic potential and the virulence of Acnnthamoebo may be determined genetically.

• Journal of Life Science
• /
• v.33 no.2
• /
• pp.158-168
• /
• 2023

Natural products have been used to mitigate the effects of cancer and infectious diseases, as they feature diverse bioactivities, such as antioxidant, antibacterial, anti-inflammatory, and immunomodulatory effects. Here, we chose 10 natural products that are well-known as pulmonary enhancers and investigated their bactericidal effects on Streptococcus pneumoniae. In the disk diffusion assay, the growth of S. pneumoniae was significantly regulated by G. fructus treatment regardless of extraction method used. We first adopted spraying as a novel delivery method for G. fructus. Interestingly, mice exposed to G. fructus three times a day for 2 weeks were resistant to S. pneumoniae intranasal infection (shown both through body weight loss and survival rates compared to the control group). Moreover, we confirmed that exposure to G. fructus regulated the colonization of the bacteria despite the sustained inflammation in the lung after exposure to S. pneumoniae, indicating that migrated inflammatory immune cells may involve a host defense mechanism against pulmonary infectious diseases. While a similar number of granulocytes (CD11b⁺Ly6C⁺Ly6G⁺), neutrophils (CD11b⁺Ly6C^intLy6G⁺), and monocytes (CD11b⁺Ly6C^intLy6G^-) were found between groups, a significantly increased number of alveolar macrophages (CD11b⁺CD11c^hiF4/80⁺) was detected in BAL fluids of mice pre-exposed to G. fructus at 5 days after S. pneumonia infection. Taken together, our data suggest that this usage of G. fructus can induce protective immunity against bacterial infection, indicating that facial spray may be helpful in enhancing the defense mechanism against pulmonary inflammation and in evaluating the efficacy of natural products as immune enhancers against respiratory diseases.

• Korean Journal of Veterinary Research
• /
• v.22 no.2
• /
• pp.211-219
• /
• 1982

Chickens from 10 to 32 weeks of age were inoculated with P. multocida via seven routs(intravenous, intramuscular, intraperitoneal, subcutaneous, into ear, intranasal, per oral). The development or distribution of disseminated intravascular coagulation (DIC) in multiple organs and the role of P. multocida endotoxins in disease process of fowl cholera were studied. The histological diagnosis of DIC was made by demonstration of fibrinous in arterioles, capillaries, venules and medium-sized blood vessels. The presence of fibrinous thrombi in blood vessels of multiple organs was observed in chickens which died within approximately 3 days post inoculation. Fibrinous thrombi were observed most frequently in the lung(90% of all cases with DIC) followed by liver (70%), kidney (60%), heart(20%), spleen, brain, pancreas, thymus and thyroid gland. The density of fibrinous thrombi (i.e. the number of thrombi per section) was greatest in the lung, followed by spleen, kidney, liver and heart. It is thought that the widespread hemorrhage of acute fowl cholera is also caused by P. multocida endotoxin which initiates DIC in variety of organs. The cause of death for the chickens after infection with acute fowl cholera is probably due to an endotoxin (septic) shock accompanied with DIC in multiple organs.