Culture, Organization, and Direction

Biopsy or blood specimens may be cultured for Leishmania spp. or T. cruzi with Novy-MacNeal-Nicolle (NNN) medium. Biopsy specimens are ground in a small amount of saline. Biopsies from skin lesions or other tissues which may contain bacteria may have penicillin (0.1 ml of 1,000 U/ml) added to the medium with the inoculum. The inoculum is 1 drop of ground tissue or blood. Incubate the culture at room temperature (22°C), and at days 3 and 7, examine a direct mount of liquid from the bottom of the slant at x400 magnification. These cultured organisms are potentially infective for humans. 

Whitmore D, Foulkes N, Sassone-Corsi P 2000 Light acts directly on organs and cells in culture to set a vertebrate circadian clock. Nature 404 87-91... 

During cheese ripening, proteases associated with starter culture organisms are released into cheese after cell lysis (Law et al. 1974). The proteolytic activity associated with lysed lactic streptococci is necessary for proper flavor development in Cheddar and other cheese varieties. The role of streptococcal proteases and peptidases appears to be production of flavor compound precursors such as methionine and other amino acids, rather than direct production of flavor compounds (Law et al. 1976A). Additional discussion of cheese ripening is presented in Chapter 12. 

Efficient mutagenicity tests that use experimental organisms and in vitro systems are a product of great advances in basic knowledge and of a substantial research effort. The principal task of the Committee is to study how the results of such tests can be used to assess the risk to future human populations. There are no reliable data from direct human experience, so it is necessary to rely on experimental test systems. Some tests are exquisitely sensitive to chemical mutagens, but use microorganisms or mammalian-cell cultures of uncertain relevance to human... 

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