Gram-positive bacteria strains

It is a glycopeptide antibiotic and primarily active against gram positive bacteria, strains of Staph, aureus which are resistant to methicillin are inhibited by vancomycin. It is also effective against Strep, viridans, enterococcus, Clostridium dijficile and diphtheroids. 

The nocardicins (A to G) have been isolated from a strain ofNocardia and comprise a novel group of /3-lactam antibiotics (Fig. 5.6A). Nocardicin A is the most active member, and possesses significant activity against Gram-negative but not Gram-positive bacteria. 

Employed as a sodium salt, fusidic acid (Fig. 5.14B) is achve against many types of Gram-positive bacteria, especially staphylococci, although streptococci are relatively resistant. It is employed in the treatment of staphylococcal infections, including strains resistant to other antibiotics. However, bacterial resistance may occur in vitro and in vivo. 

The introduction of techniques for mutagenesis by UV irradiation or by the use of chemicals considerably extended the applications of microbial studies to nutrition (Davis, 1954-1955). Auxotrophic mutants were produced with nutrient dependencies not shown in the untreated parental strains (Beadle and Tatum, 1940). The fortuitous discovery of penicillin by Fleming and its successful use in the treatment of infections (Florey) promoted exhaustive research into its mode of action. Eventually it was established that penicillin prevented the proliferation of gram-positive bacteria by blocking the synthesis of their cell walls... 

Cyclopropyl fatty acids with C12, Cjg and C21 have been formed in many gram-negative and gram-positive bacteria [198]. The mycolic acid 142 (Cso) is a major component of the mycobacterial cell wall of the human strain of M. tuber-culosiSyEq. (57) [199]. 

Moxalactam is resistant to the action of beta-lactamase, penicillinase, and cephalospori-nase, which are produced by Gram-negative and Gram-positive bacteria. Many strains of... 

---