Chapter 10B Offensive and Defensive Strategies

antigenic drift

A process by which point mutations in influenza virus genes cause differences in the structure of viral surface antigens. This causes year-to-year antigenic differences in strains of influenza virus.

capsule

A sticky layer that surrounds the cell walls of some bacteria, protecting the cell surface and sometimes helping to glue the cell to surfaces.

endotoxin

A toxic component of the outer membrane of certain gram-negative bacteria that causes the immune system to overreact

neutrophil

A type of white blood cell that engulfs invading microbes and contributes to the nonspecific defenses of the body against disease. (first responders)

Tamiflu (oseltamivir)

Antiviral agent that works against influenza by inhibiting neuraminidase, which prevents infected cells from shedding virus

pili

Appendages that allow bacteria to attach to each other and to transfer DNA

urease

Enzyme that changes urea into ammonia and carbon dioxide - this protects H. pylori from stomach acid

Hemagglutinin

One of the enzymes found on the surface of the Influenza virus. It is responsible for binding the virus to the cell that is being infected. (this is the virus's way into a cell)

antigenic variation

Pathogens alter their surface antigens (and antibodies are rendered ineffective because they recognized the old antigens)

specific receptors

Target cells must have proteins that the pathogen can regcognize/bind to

neurotoxin

Toxins produced by bacteria that disrupt the nervous systems of animals

enterotoxin

a toxin produced in or affecting the intestines, such as those causing food poisoning or cholera.

exotoxin

a toxin released by a living bacterial cell into its surroundings.

pathogenicity

ability of a microorganism to cause disease

offensive strategies

adaptations by microbes that result in their ability to damage the host and establish disease

hemolysin

an enzyme that breaks down red blood cells

hyaluronidase

bacterial enzyme that is secreted and digests polysaccharides that hold cells together

collagenase

ennzyme made by bacteria that will break down collagen which forms connective tissue of host

cytotoxin

exotoxin made by bacteria that kills host cells or alters their function

adhesin

general term for any microbial factor that promotes attachment

toxoid

inactivated toxin used in a vaccine (e.g. tetanus toxin)

incubation

period where pathogens are multiplying in a host (before symptoms appear)

Pneumovax 23

pneumococcal polysaccharide vaccine - vaccinates host and provides antibodies against streptococcal capsules

defensive strategy

processes bacteria use to attach to a host cell and evade the immune system

antigenic shift

the process by which two or more different strains of a virus, or strains of two or more different viruses, combine to form a new subtype having a mixture of the surface antigens of the two or more original strains.