Draining lymph node enlargement produced by immunogenic strains of cultivable mycobacteria.

Lymphnode enlargement produced by strains of mycobacteria have a direct bearing on the immunogenicity characteristics. Two strains of mycobacteria namely M. habana TMC 5135 and M. marinum (SATO) have been studied for their property to produce enlargement of draining lymphnodes besides other cell-mediated immune responses. Both the strains are capable of producing the enlargements of inguinal and popliteal lymphnodes which is very significant. The enlargements of lymphnodes have been produced by these strains both in the live as well as killed state. Possibility of developing these strains as vaccine against leprosy has been discussed.

Evaluation of subdermal biodegradable implants incorporating rifampicin as a method of drug delivery in experimental tuberculosis of guinea pigs.

Conventional chemotherapy of tuberculosis and leprosy requires rifampicin to be administered orally. The long period of treatment and adverse side effects of the drug lead to poor compliance. To overcome this, subdermal implants incorporating rifampicin in pure and micro-encapsulated forms with biodegradable material were used as a new drug delivery system in experimental tuberculosis of guinea pigs. Two experiments were performed with 45-mg and 100-mg drug implants. Progress of infection was followed at intervals by studying necropsy scores and weights of the organs of predilection and levels of the drug in the blood were determined. There was a constant and sustained release of the drug in therapeutic concentrations for 30 and 50 days until the implants were completely assimilated without causing any damage to the implant site. The importance of multiple implants at long intervals is discussed.

Leucocyte migration inhibition response of Mycobacterium habana with sensitized animals and cells from leprosy patients.

Response of Mycobacterium habana sensitized mouse cells against habanin (sonicated extract) lepromin (Dharmendra) and tuberculin has been studied in the leucocyte migration inhibition test. The homologous antigenic response has evoked maximum inhibition as compared to heterologous antigens but close antigenic association has also been observed with lepromin and tuberculin. With human cells from leprosy patients these antigens have evoked analogous response indicating cross immunogenicity of M. habana with leprosy sensitized cells.

Increased susceptibility of rabbits to intravenous challenge with Mycobacterium avium after mild hepatitis produced by carbon tetrachloride.

A mild grade of liver damage in rabbits was produced by giving 23 subcutaneous injections of carbon tetrachloride (CCl4). The CCl4-treated rabbits and untreated controls were subsequently challenged with the mildly virulent strain of Mycobacterium avium Kirschberg (TMC 801). In two successive experiments it has been found that liver damage increased the susceptibility of rabbits to infection with this organism.

Antibiotic X-63 in experimental candidiasis of mice.

X-63, a polyene antibiotic of heptaene series showed activity against experimental infection with Candida albicans in mice, by several routes. The oral, intraperitoneal and intravenous activities ranged between dosages of 3.1--50, 0.06--0.5 and 0.25--0.5 mg/kg, respectively. Seven days treatment by intraperitoneal route caused significant progressive reduction of colony-forming units in kidney homogenates of infected mice, which was comparable to amphotericin B. The regression of infection was further demonstrated histopathologically. In vitro, antibiotic X-63 was similar to nystatin against nine strains of Candida used. It also proved active against amphotericin B-resistant strains of C. albicans, C. tropicalis, C. pseudotropicalis, C. krusei, and C. parakrusei. The use of combined drug therapy in candidiasis has been discussed.

Mycotic keratitis due to Rhizoctonia sp.

A case of mycotic keratitis due to Rhizoctonia sp. is reported for the first time. Fungal hyphae were detected in corneal scrapings and cultures were found positive for Rhizoctonia sp. on two occasions. Species could not be identified and it has been disposed in Herb. IMI as Rhizoctonia sp. (IMI 200029). The isolate grew faster at 37 degrees C than at 28 degrees C and its pathogenicity was established in rabbit's eye.