Antibiotics and Immunity

Antibiotics refer to drugs that are used to treat infectious diseases in humans, animals or plants.  They work by inhibiting the growth of or killing microorganisms causing the disease.  Antimicrobials is a broader term that  refers  to any compound, including antibiotics, sanitizers, disinfectants, a number of food preservatives and other substances, that acts to inhibit the growth of or kill microorganisms.

Rifamycin is primarily an antibacterial antibiotic effective against mycobacteria (tuberculosis, leprosy), not an antiviral agent. Actinomycin D is correctly matched as anti-tumor, Daunorubicin as anti-tumor/anti-cancer (not anti-protozoal), and Griseofulvin as anti-fungal. Therefore, only pair 3 (Rifamycin - Anti viral) is incorrectly matched.

Treponema pallidum cannot be cultivated in laboratory. It can be developed in tissue cultures. Plain serologic screening tests like VDRL test (Venereal Disease Research Laboratory test) or RPR (Rapid plasma Reagin test) are usually used for diagnosis of syphilis. Cardiolipin, a nontreponemal antigen is used for the test.

Many genera in the high GC gram positive bacterial group such as Mycobacterium and Nocardia contain mycolic acids embedded in the peptidoglycan. Mycolic acids are a class of waxy extremely hydrophobic lipids. Certain genera contain very large amounts of this lipid and are difficult to gram stain. These genera may be identified by the acid fast staining technique.

This option is correct as  penicillin is a narrow spectrum antibiotic and effective against diseases caused by various cocci and some gram positive bacteria.

This option is correct as dettol and savlon are antiseptics. Antiseptics are chemicals that are used externally to prevent the growth of microbes or pathogens. Antibiotics are anti-bacterial drugs but antiseptics are active against bacteria as well as other microbes. Antiseptics are milder in comparison to the disinfectants and hence they can be applied on the skin. All antimicrobial chemicals are not antiseptics.

This option is correct as antibacterial drugs are antibiotics.

They prevent ribosomal association at the end of initiation step and cause misreading of the genetic code.

Antibiotic treatments for one to three days shorten the course of the disease and reduce the severity of the symptoms. Use of antibiotics also reduces fluid requirements. Doxycycline is name of the antibiotic used against cholera.

Antiseptics are chemical substances that inhibit the growth of bacteria and are commonly used on the site of infection.

Penicillin obtained from penicillium notation is an antibiotic, not antibody. Hence this statement is wrong.

In 2014, a novel antibiotic called Teixobactin was found in Eleftheria terrae. Teixobactin was the first new antibiotic discovered since the synthetic era of the 1980s, thus it was a major discovery.

There is no known cure for fire blight. Disease can be prevented by injecting plants with oxytetracycline.

Streptomyces is the largest genus of Actinobacteria and the type genus of the family Streptomycetaceae. Chloramphenicol is known as a broad-spectrum antibiotic, which is synthesized by streptomyces species.