Nalidixic acid is credited to be the first quinolone synthesized in laboratory in 1962. Its chemical structure is shown in Fig. 45.16. It is a broad spectrum chemotherapeutic agent and is useful against gram-negative bacteria (causing urinary tract infection) and some gram-positive ones. Nalidixic acid is bactericidal and is effective when administered orally. This antibiotic sometimes causes side effects, particularly [...]
In this article we will discuss about:- 1. Structure of Tetracylines 2. Antibiotic Spectrum of Tetracylines 3. Mechanism of Action. Structure of Tetracylines: All members of the group of tetracyclines consist of a common four-ring structure to which a variety of side chains (R1, R2, R3) are attached (Fig. 45.14). Antibiotic Spectrum of Tetracylines: Tetracyclines are broad-spectrum bacteriostatic antibiotics active [...]
The following points highlight the top six defence mechanisms involved in innate immunity. The defence mechanisms are: 1. Physical (or Mechanical) and Chemical Barriers 2. Inflammation 3. Phagocytosis 4. The Complement System 5. Antibacterial Substances 6. Antiviral Substances. Mechanism # 1. Physical (or Mechanical) and Chemical Barriers: Physical (or mechanical) barriers of the host in cooperation with chemical barriers (secretions) [...]