Broad-spectrum antibiotic their greater potential to disrupt a larger variety of normal human flora. After continued exposure to an antibiotic, bacteria may develop changes in their structure or function that make them resistant to the antibiotic. These resistant organisms will live, while the susceptible organisms will die, leaving the population of bacteria entirely resistant to a given antibiotics. For example, after the discovery of penicillin and its subsequent use to treat bacterial infections, bacteria were found to have begun producing an enzyme, penicillinase, which rendered the penicillin molecule inactive. In response to this newly-acquired resistance, newer penicillins were produced that could not
Quinolone antibiotic Quinolone antibiotic A quinolone antibiotic is any member of a large group of broad-spectrum bactericides that share a bicyclic core structure related to the compound 4-quinolone. They are used in human and veterinary medicine to treat bacterial infections, as well as in animal husbandry. Nearly all quinolone antibiotics in use are fluoroquinolones, which contain a fluorine atom in their chemical structure and are effective against both Gram-negative and Gram-positive bacteria. One example is ciprofloxacin, one of the most widely used antibiotics worldwide. Fluoroquinolones are often used for genitourinary infections and are widely used in the treatment of hospital-acquired infections associated