Gram-positive

Erythromycin is active against gram-positive and certain gram-negative bacteria, also against Rickettsia and spirochaetes. It is used for patients who are allergic to or do not respond to treatment with penicillins or tetracyclines. 

Tetracyclines are broad-spectrum antibiotics. effective against Gram-positive and Gram-negative bacteria, also against Rickettsiae (typhus fever) and certain other organisms. 

Bacillus sp. These bacteria are gram-positive soil microbes. Members of the Bacillus species supply 58% of iadustrial enzymes sold (19). Eor example, proteases from B. amjloliquefaciens and amylases from B. licheniformis glucose isomerase from B. coagulans are used ia a variety of iadustrial processes (see Enzyme applications-industrial). The proteiaaceous iaclusioas produced by B. thuringiensis are useful as iasect toxias. Thus exteasive fermentation technology has been developed for Bacillus species and low cost media are available (19). 

Clostridium. This geaus is comprised of a heterogeaeous assemblage of obligate, anaerobic, gram-positive, endospore-forming bacteria (21). 

Lactic Acid B cteri. The lactic acid bacteria are ubiquitous in nature from plant surfaces to gastrointestinal tracts of many animals. These gram-positive facultative anaerobes convert carbohydrates (qv) to lactic acid and are used extensively in the food industry, for example, for the production of yogurt, cheese, sour dough bread, etc. The sour aromatic flavor imparted upon fermentation appears to be a desirable food trait. In addition, certain species produce a variety of antibiotics. 

The 5-position of quinolones can be substituted by small groups such as halogens, hydroxyl, or amino (54—56). The amino group at this position can be advantageous, particularly when appHed to 6,8-difluoro-7-piperazinyl or 6,8-difluoro-7-pyrrohdinyl quinolones. In contrast to 6,8-difluoro quinolones, when this replacement is appHed to ofloxacin, the resulting derivative has reduced antibacterial activity (57). Replacement of the 5-amino group with methylamine or dimethylamine causes activity to drop substantially. Sparfloxacin [110871-86-8] (21), a representative of 5-amino-6,8-difluoro quinolones, affords modest improvements in gram-positive activity as well as increased in vivo potency when compared with both ciprofloxacin and ofloxacin (54). 

Lincomycin. The liacomycias and celesticetins are a small family of antibiotics that have carbohydrate-type stmctures. Clindamycin, a chemical modification of lincomycin, is clinically superior. Antibiotics ia this family inhibit gram-positive aerobic and anaerobic bacteria by interfering with proteia biosyathesis. 

Tetracyclines. The tetracycliaes are a small group of antibiotics characterized as containing a polyhydronaphthacene nucleus. Commercially the tetracyclines are very important. They have been used clinically against gram-positive and gram-negative bacteria, spirochete, mycoplasmas, and rickettsiae... 

Tolypomycin Y (48) shows strong antibacterial activity against gram-positive bacteria and Neisseriagonorrheae. When adininistered by subcutaneous, intraperitoneal, and intravenous routes, tolypomycin Y is effective in mice infected with Staphylococcus aureus Streptococcuspyrogenes and Diplococcuspneumoniae. Cross-resistance is observed with rifampicia but not with other antibiotics. Resistance to tolypomycin Y develops rapidly. The bioactivity of tolypomycin R... 

Kanglemycin. Kanglemycia (74) (Fig. 8) is isolated from the fermentation broth filtrate of Nocardia mediterranei var kanglensis (1747-64) and its stmcture determiaed by x-ray crystallographic studies. The antibiotic is active against gram-positive bacteria (28). 

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