Which of the following is active against atypical mycobacteria?
High-Yield Explanation
Clarithromycin: The antimicrobial spectrum of clarithromycin is similar to erythromycin; in addition, it includes Mycobact. avium complex (MAC), other atypical mycobacteria, M.leprae and some anaerobes but not Bact.fragilis. It is more active against sensitive strains of gram-positive cocci, Moraxella, Legionella, Mycoplasma pneumoniae and Helicobacter pylori. However, bacteria that have developed resistance to erythromycin are resistant to clarithromycin also. Rifabutin: It is related to rifampin in structure anC. mechanism of action; but less active against M. tuberculi and more active against MAC.For the treatment of established MAC infection, it has been added to ethambutol + clarithromycin/ azithromycin Ciprofloxacin (prototype): It is the most potent first generation FQ acti\*e against a broad range of bacteria, the most susceptible ones are the aerobic gram-negati\*e bacilli, especially the Enterobacteriaceae and Neisseria. The MIC of ciprofloxacin against these bacteria is usually < 0.1 J.Ig/ml, while grampositive bacteria are inhibited at relatively higher concentrations. The spectrum of action is summarized below: Highly susceptible: E. coli K. pneumoniae Enterobacter Salmonella typhi other Salmonella Shigella Proteus Neisseria gonorrhoeae N. meningitidis H. influenzae H. ducreyi Campylobacter jejuni Yersinia enterocolitica Vibrio cholerae Moderately susceptible: Pseudomonas aeruginosa Staph. aureus (including few MRSA) Staph. epidermidis Branhamella catarrhalis Legionella Brucella Listeria Bacillus anthracis Mycobact. tuberculosis ESSENTIALS OF MEDICAL PHARMACOLOGY K.D.TRIPATHI SIXTH EDITION PAGE NO:688,689,730,744