Gram-negative bacteria quinolones

Quinolones and fluoroquinolones inhibit DIMA gyrase (prokaryotic topoisomerase II), preventing DNA replication and transcription. These dmgs, which are most active against aerobic gram-negative bacteria, indude ... 

TABLE 4.6. MICgo of GAR Compared with Other Quinolones Against Gram-Positive and Gram-Negative Bacteria... 

It is 4-quinolone derivative effective against gram negative bacteria mainly . coli and Shigella. It is less effective against Klebsiella and Aerobacter species and very... 

Nalidixic acid is a first-generation quinolone that exhibits antibacterial activity against various gram-negative bacteria. It has been used exclusively in Japan for treatment of vibriosis and furunculoses of plasmonids. 

Very few synthetic compounds other than the sulfa drugs have shown useful activity against systemic bacterial infections, particularly those due to Gram-negative bacteria. Activity of this kind was discovered in a series of l-alkyl-4-quinolones (60BRP830832), but the most active of these, l,2-dimethyl-6-nitro-4-quinolone and l-methyl-6-nitro-4-quin-olone-3-carboxylic acid, produced eye damage (opacity of the lens) that precluded clinical trial. A closely related 1,8-naphthyridine derivative, nalidixic acid (255), was later found to be effective, and it is largely used for urinary tract infections. The quinolone oxolinic acid (256) is also used for this purpose. These compounds inhibit enzymes concerned in DNA synthesis. 

DuggiralaA, Sharma JJ, Nutheti R, et al. Activity of newer flouro-quinolones against gram-positive and gram-negative bacteria isolated from oculsr infections an in vitro comparison. Indian J Ophthalmol 2007 55 15-19. 

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