Antibiotics and Immunity

Cefotaxime is a third-generation cephalosporin antibiotic. Third-generation cephalosporins have enhanced activity against gram-negative bacteria compared to earlier generations, while maintaining some gram-positive coverage. Cefotaxime is commonly used for serious infections like meningitis, septicemia, and respiratory tract infections.

Streptomycin: Streptomyces griseus Chloramphenicol: Streptomyces venezuelae Oxytetracycline: Streptomyces rimosus All these antibiotics are derived from members of genus Streptomyces.

Pyocin synthesis is directed by the bacteriocinogenic plasmids in pseudomonas. They are active against bacteria.

Alexander Fleming discovered the antibacterial properties of penicillin in 1928 when he observed that mold from the Penicillium fungus prevented bacterial growth in a petri dish. This accidental discovery revolutionized medicine.

Yes, it is the correct answer. A and R both are correct and R is correct explanation of A. Gram-positive bacteria are generally resistant to complement-mediated lysis because thick peptidoglycan layer prevents insertion of membrane attack complex into the inner membrane.

Teichoic acids are unique components found exclusively within the thick peptidoglycan cell walls of Gram-positive bacteria. Lipopolysaccharides are characteristic of Gram-negative outer membranes.

A gene whose expression allows one to identify cells that have been transformed or transfected with a vector containing the marker gene is known as a selectable marker which helps in identifying and eliminating non-transformants and selectively permitting the growth of the transformants. Normally, the genes encoding resistance to antibiotics such as ampicillin, chloramphenicol, tetracycline or kanamycin, etc. are considered as useful selectable markers for Escherichia coli. Hence, the set ‘ampicillin, chloramphenicol, tetracycline’ represents selectable marker for Escherichia coli.

Amoxicillin acts by disrupting the synthesis of the peptidoglycan layer of bacterial cell walls.

Alexander Fleming discovered penicillin in 1928, but the first successful purification and isolation of pure penicillin was achieved by Howard Florey and Ernst Chain in the late 1930s. Fleming's original penicillin was unstable and difficult to purify. Florey and Chain's work made penicillin usable as a drug.

Alexander Fleming discovered penicillin in 1928 from the mold Penicillium notatum. This species produced the antibiotic compound that inhibited bacterial growth. While industrial production later used P. chrysogenum for higher yields, the original discovery was from P. notatum. P. camemberti is used in cheese production, and P. 'roguefoth' appears to be a misspelling or non-existent species name.

This is the correct option as this statement is false. Virus, bacteria and fungi multiply very quickly, but worms multiply very slowly.

This is the correct option as ciprofloxacin is the drug that is used to cure typhoid.

Yes, it is the correct answer. Antibiotics are chemical substances which are produced by some microbes and can kill or retard the growth of other disease-causing microbes. For example, pencillin.