Bacterial infection, lymph nodes

Albino male guinea pigs were infected by subcutaneous injection of 0.001 mg of bacterial (M. tuberculosis) coating and treated with rifamycins by oral route immediately after the infection. The antibiotic treatment lasted 4 months, after which the animals were sacrificed and inguinal lymph nodes, spleen, liver and lungs examined to quantify the severity of the disease according to Feldman [75],... 

Signs and Symptoms Initial symptoms include fever, watery eyes, increased nasal secretions, drooling (ptyalism), diarrhea, loss of appetite, reduced milk production, depression, and reluctance to move. This is followed by the eruption of various sized skin nodules that may cover the whole body. They can be found on any part of the body but are most numerous on the head and neck, perineum, genitalia and udder, and the limbs. The nodules are painful and involve all layers of the skin. Skin lesions may show scab formation. Regional lymph nodes are enlarged and full of fluid. Secondary bacterial infection can complicate healing and recovery. Final resolution of lesions may take 2-6 months, and nodules can remain visible 1-2 years. 

Coxiella burnetii is a highly infectious bacterium. A single bacterial cell can produce clinical illness. For this reason it is a very strong candidate for use by terrorists via aerosol delivery. While the incubation period is 2 to 14 days, the average is 7 days. In rare instances, incubation period can extend up to 1 month. After infection and proliferation in the lungs, the organisms are picked up by macrophages and carried to the lymph nodes, and from there to the bloodstream. 

A variety of diseases affect the lymphatic system early in their time course. For example, many cancers spread by lymphatic dissemination, and HIV, fungal, and bacterial infections are located primarily in the lymph nodes. The high prevalence of lymph node involvement in disease is due to the role of lymphatic tissue in the provision of the body s immune response. Intralymphatic and interstitial administration are two efficient access routes. However, the oral route may also prove to be important for the lymphatic uptake of lipophilic drags and macromolecules. 

This multifactorial weakness in defence allows bacterial penetration of the ascitic fluid to be effected by (1.) transmural migration in portal hypertension with greater permeability of the intestinal wall, (2.) systemic bacteraemia in terms of haematogenic dispersion (particularly in urinary tract and bronchopulmonary infections), above all in the presence of intrahepatic and extrahepatic shunts (so-called portal vein bacteraemia), (3.) invasion of bacteria via the Fallopian tubes, and (4.) lymphatic flow into the ascitic fluid (e.g. via leaks in the lymph vessels or lymph nodes). 

Intermediate-duration oral studies of Aroclors in monkeys confirm the observations of PCB immunotoxicity in rats, mice, guinea pigs, and rabbits and further indicate that nonhuman primates are more sensitive than the other species. Early studies found decreased antibody responses to SRBC, increased susceptibility to bacterial infections, and/or histopathological changes in the thymus, spleen, and lymph nodes in adult monkeys and their offspring at 0.1-0.2 mg/kg/day doses of Aroclor 1254 and 1248, although these findings are limited by small numbers of animals and dose levels (Abrahamson and... 

E. Tularemia. Franciseila tularensis bacteria usually cause infection by exposure to bodily fluids of Infected animals or from the bites of ticks or mosquitoes. Aerosolized bacteria can also be Inhaled. An initial focal, suppurative necrosis is followed by bacterial multiplication within macrophages and dissemination to lymph nodes, lungs, spleen, liver, and kidneys. In the lungs, the lesions progress to pneumonic consolidation and granuloma formation and can result in chronic interstitial fibrosis. 

---