ch 2- terminology

Question 1

Normal microbiota

Answer 1

collection of bacteria, archaea, and eukaryotic microbes usually colonizing our bodies

Question 2

Pathogen and pathogenicity

Answer 2

pathogen- any bacterium, virus, fungus, protozoan, or worm (helminth) that causes disease

Pathogenicity- the ability of an organism to cause disease

Question 3

Parasite-ecto- and endoparasite

Answer 3

any organism that colonizes and harms its host

ecto- external endo- enternal

Question 4

Infections

Answer 4

A pathogen or parasite enters or begins to grow in/on a host

Question 5

Primary pathogens vs. opportunistic pathogens

Answer 5

primary- able to breach defenses of a healthy host

opportunistic- cause disease only in a compromised host

Question 6

Latent state

Answer 6

Organism is within host but cannot be detected by culture (herpes virus)

Question 7

Virulence

Answer 7

a measure of the degree or severity of disease

Question 8

Lethal dose 50% and infectious Dose 50%

Answer 8

LD50- the number of bacteria or virus particles (virions) required to kill 50% of an experimental group of animal hosts

ID50- the number of bacteria or virions needed to cause disease symptoms in 50% of an experimental group of hosts

Question 9

Invasion and Invasiveness

Answer 9

invasion- ability of some pathogens to actually enter and live inside a host cell

invasiveness- ability of a bacterial pathogen to rapidly spread through tissue

Question 10

Narrow and Broad Host range

Answer 10

host range- Some organisms can infect only certain animals (hosts) and produce disease

narrow-Salmonella enterica serovar Typhi
can infect only humans

broad-Salmonella enterica serovar Typhimurium
can infect many different animals in addition to humans

Question 11

Host-Pathogen Interactions (Attachment, Immune Avoidance, Obtaining nutrients)

Answer 11

attachment- adhesins & their specific receptors

immune avoidance-altered surface antigens
secretion of “all is well” signals
apoptosis signals

obtaining nutrients-iron uptake (lactoferrin, transferrin)

Question 12

Disease (infectious disease)

Answer 12

disease-disruption of the normal structure or function of any body part, organ, or system that can be recognized by a characteristic set of symptoms and signs

infectious-a disease caused by a microorganism (bacterial, viral, or parasitic) that can be transferred from one host to another

Question 13

Acute, chronic, sub-acute, latent

Answer 13

acute- Symptoms develop rapidly

chronic- Symptoms develop gradually over weeks or months and are slow to resolve.

sub acute- Symptoms take longer to develop than acute but arise more quickly than chronic

latent- Infection occurs after an acute episode. Organism is present but symptoms are not

Question 14

Bacteremia, Septicemia, Viremia, Toxemia

Answer 14

bacteria-presence of bacteria in blood, usually transient, no replication

septicemia-presence and replication of bacteria in blood

viremia-presence of viruses in the blood

toxemia-presence of toxins in the blood

Question 15

Primary and secondary infection, iatrogenic, Nosocomial infection

Answer 15

primary-infection in a previously healthy individual

secondary-follows a primary infection

iatrogenic-infection transmitted from a health care worker to a patient

nosocomial-infection acquired during a hospital stay

Question 16

Sign and Symptom—be able to recognize signs vs. symptoms

Answer 16

sign-something that can be observed by a person examining a patient
runny nose
rash

symptom-something that can be felt only by the patient
pain
malaise

Question 17

Know the 5 stages of infections (define Acme, too) and what is occurring in each one, are symptoms present or not, are you contagious

Answer 17

Incubation Period-time after the microbe first infects a host but before the first signs of disease

Prodromal Phase-short period of vague symptoms and malaise; can serve as a warning of more symptoms to come but may not be noticed

Illness Phase-Typical symptoms and signs of the disease appear and fever may be present; acme is the point where disease is most severe.

Decline-Symptoms begin to subside; fever resolves.

Convalescence-period after symptoms disappear and patient recovers

Question 18

Morbidity vs. Mortality

Answer 18

Morbidity-existence of a disease state and the rate of incidence of the disease
Death is not required for morbidity statistics, only illness

Mortality-a measure of how many patients have died from a disease

Question 19

Modes of Transmission: direct vs indirect, fecal-oral, parenteral, urogenital, etc

Answer 19

direct-Organisms may spread directly from person to person

indirect-Organisms may spread indirectly through an intermediary, which may be living or non-living

fecal-

oral-

parenteral-

urogenital-

Question 20

Reservoir, carrier, vector, fomite

Answer 20

Reservoir of Infection - an animal or an environment that normally harbors the pathogen

Carrier -person who harbors a potential disease agent but does not have signs or symptoms of disease

Question 21

Endemic, epidemic, pandemic

Answer 21

endemic-always present in a community and seen at a low rate; often harbored in an animal reservoir

epidemic-many cases developing in a community in a short time

Question 22

Know portals of exit and entry

Answer 22

Fecal-oral -through mucosal surfaces of gastrointestinal tract
Skin
through epithelial surfaces
Respiratory-through mucosal surfaces of respiratory tract
Urogenital-through mucosal surfaces of genital and urinary tracts
Parenteral-through injection into the bloodstream
insect bites
wounds/needle sticks

Question 23

mutalism

Answer 23

relationship in which community members and host both benefit