Question

Bacteria that cause sexually transmitted diseases are generally only found in fluid environments (particularly body fluids), and are often gram-negative. Such infections are not transmitted through casual contact. Bacteria that cause respiratory infections and sore throats are commonly transmitted through casual contact, and are often gram-positive. Explain both of these situations using cell wall structure.

Answer 1

Gram positive bacteria which cause respiratory infections are Mycobacterium tuberculosis. This bacterium causes tuberculosis. These bacteria have different structures of cell wall. They have outermost layer of peptidoglycan which renders them more susceptible to the action of WBCs.

Gram negative bacteria like Neisseria Gonorrheae, Treponema pallidium causes Syphillis. These bacteria have a lipid layer above the layer of peptidoglycan which helps them escape the WBCs.

All bacteria have an inner cell membrane, gram-negative bacteria have a unique outer membrane. This outer membrane excludes certain drugs and antibiotics from penetrating the cell, partially accounting for why gram-negative bacteria are generally more resistant to antibiotics than are gram-positive bacteria.