The pathogen of bubonic plague is transmitted through the bite of

For which of the following diseases have antibiotics been discovered?

Which of the following is a diagnostic test for typhoid?

Which pathogen is responsible for $TB$ (Tuberculosis)?

Assertion: $Escherichia$ $coli$,$Shigella$ $sp.$ and $Salmonella$ $sp.$ are all responsible for diarrhoeal diseases.
Reason: Dehydration is common to all types of diarrhoeal diseases and adequate supply of fluids and electrolytes should be ensured.

Which one of the following diseases is caused by bacteria?