Which pair of genera are among the major sources of antibiotics used clinically?

Which pair of genera are among the major sources of antibiotics used clinically?

• A. Bacillus and Streptomyces
• B. Escherichia and Pseudomonas
• C. Saccharomyces and Candida
• D. Vibrio and Clostridium

Answer: (A)

Major sources of antibiotics used clinically come from microbes that naturally produce bioactive compounds to outcompete other organisms in their environment. Streptomyces species are the most prolific producers of antibacterial agents; many antibiotics used in medicine—such as streptomycin and tetracycline—were originally isolated from Streptomyces. Bacillus species also contribute important peptide antibiotics, including bacitracin and polymyxin B. Together, these two genera account for a large portion of clinically used antibiotics. The other groups given are not known as major sources of clinically used antibiotics. Escherichia and Pseudomonas are common Gram-negative bacteria that can be targets of antibiotics but are not primary producers of the drugs themselves; Saccharomyces and Candida are yeasts, not primary sources of widely used antibiotics; Vibrio and Clostridium are diverse genera associated with disease rather than being major antibiotic producers.

Major sources of antibiotics used clinically come from microbes that naturally produce bioactive compounds to outcompete other organisms in their environment. Streptomyces species are the most prolific producers of antibacterial agents; many antibiotics used in medicine—such as streptomycin and tetracycline—were originally isolated from Streptomyces. Bacillus species also contribute important peptide antibiotics, including bacitracin and polymyxin B. Together, these two genera account for a large portion of clinically used antibiotics.

The other groups given are not known as major sources of clinically used antibiotics. Escherichia and Pseudomonas are common Gram-negative bacteria that can be targets of antibiotics but are not primary producers of the drugs themselves; Saccharomyces and Candida are yeasts, not primary sources of widely used antibiotics; Vibrio and Clostridium are diverse genera associated with disease rather than being major antibiotic producers.