microbio chapter 15 vocab

A-B exotoxins

class of exotoxin that contains A subunits, which enter the cell and disrupt cellular activities, and B subunits, which bind to host cell receptors

adhesion

the capability of microbes to attach to host cells

Aflatoxin

chemical produced by the fungus Aspergillus flavus; both a toxin and the most potent known natural carcinogen

antigenic variation

changing of the surface antigens (carbohydrates or proteins) such that they no longer recognized by the host’s immune system

bacteremia

condition marked by the presence of bacteria in the blood

coagulase

enzyme that causes the activation of fibrinogen to form fibrin, promoting clotting of the blood

collagenase

enzyme that digests collagen, the dominate protein in connective tissue

DNAse

pathogen-produced nuclease that degrades extracellular DNA

endotoxin

lipid A component of lipopolysaccharides in the outer membrane of gram-negative bacteria

Enterotoxin

toxin that affects the intestines

exoenzyme

secreted enzyme that enhances the ability of microorganisms to invade host cells

exotoxin

biologically active product that causes adverse changes in the host cells

Glycohydrolases

degrades hyaluronic acid that cements cells together to promote spreading through tissues

hemolysin

class of exotoxin that targets and lyses red blood cells, as well as other cells

hyaluronidase

enzyme produced by pathogens that degrades hyaluronic acid between adjacent cells in connective tissue

Leukocidin

class of exotoxin that targets and lyses leukocytes

membrane-disrupting toxins

toxin that affects cell membrane function by either forming pores or disrupting the phospholipid bilayer

Nucleases

degrades DNA released by dying cells (bacteria and host cells) that can trap the bacteria, thus promoting spread

opportunistic pathogen

microorganism that can cause disease in individuals with compromised host defenses

pathogenicity

ability of a microbial agent to cause disease

Phospholipases

degrades phospholipid bilayer of host cells, causing cellular lysis, and degrade membrane of phagosomes to enable escape into cytoplasm

primary pathogen

microorganism that can cause disease in the host regardless of the effectiveness of the host’s immune system

Proteases

degrades collagen in connective tissue to promote spread

secondary infection

second infection that develops after a primary infection as a result of the primary disease compromising immune defenses or antibodies, thus eliminating protective microbiota

septic

the condition of being septicemic; having an infection in the blood

septicemia

condition in which pathogens are multiplying in blood

shock

extreme drop in blood pressure that, among other causes, can result from a strong immune response to the activity of toxins or response to bacterial products and can result in death

superantigens

class of exotoxin that triggers a strong nonspecific immune response with excessive production of cytokines (cytokines storm) causing inflammation, high fever, shock, and, potentially death

toxemia

presence of toxins in the blood

toxigenicity

ability of a pathogen to produce toxins to cause damage to host cells

toxin

poison produced by a pathogen

viremia

presence of virus in blood

virulence

degree to which an organism is pathogenic; severity of disease signs and symptoms

virulence factor

product of a pathogen that assists in its ability to cause infection and disease

protease

enzyme involved in protein catabolism that removes individual amino acids from the ends of peptide chains