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| | penicillin. The Columbia Encyclopedia, Sixth Edition. 2001-05 (Site not responding. Last check: ) |
 | | Although he recognized the therapeutic potential of penicillin, it was not until 1941 that a group of biologists working in England, including Oxfords Sir H. Florey and E. Chain, purified the substance and established its effectiveness against infectious organisms and its lack of toxicity to humans. |
 | | Penicillin is effective against many gram-positive bacteria (see Grams stain), including those that cause syphilis, meningococcal meningitis, gas gangrene, pneumococcal pneumonia, and some staphylococcal and streptococcal infections. |
 | | Synthetically produced penicillins such as methicillin and oxacillin have been developed that are not degraded by the penicillinase enzyme, but these new penicillins have no effect on bacteria that have developed resistance by other means, e.g., by altered cell wall structure. |
| www.bartleby.com /65/pe/penicill.html (533 words) |
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