microbiology test chapters 9, 10, 11

prodromal stage

1-2 day period when the earliest notable symptoms of infection appear

syndrome

a disease identified by a certain complex of signs and symptoms

communicable

a disease in which an infected host can transmit the infectious agent to another host

contagious

a disease that is highly communicable, especially through direct contact

latency

a dormant state of microbes in certain chronic infectious disease - viral, bacterial

septicemia

a general state in which microorganisms are multiplying in the blood and are present in large numbers

toxin

a specific chemical product of microbes, plants, and some animals that is poisonous to other organisms

virulence

ability of a microbe to establish itself and harm the host

necrosis

accumulated damage due to pathogens leading to cell and tissue death

biological vector

actively participates in a pathogen's life cycle, serving as a site in which it can multiply or complete its life cycle

sporicide

an agent capable of destroying bacterial endospores

carrier

an individual who inconspicuously shelters a pathogen and spread it to others

zoonosis

an infection indigenous to animals but naturally transmissible to humans

noncommunicable

an infectious disease that does not arise through transmission of the infectious agent from host to host

endemic

an infectious disease that exhibits a relatively steady frequency over a long time period in a particular geographic locale

pathogenicity

an organism's potential to cause infection or disease

asepsis

any practice that prevents the entry of infectious agents into sterile tissues and thus prevent infection

bacteremia or viremia

bacteria or viruses are present in the blood but not multiplying

true pathogens

capable of causing disease in healthy persons with normal immune defenses

mechanical vector

carries the microbe more or less accidentally on its body parts

coagulase

causes clotting of blood or plasma

phagocytes

cells that engulf and destroy host pathogens by means of enzymes and antimicrobial chemicals

antiseptics

chemical agents applied directly to exposed body surfaces (skin and mucous membranes), wounds, and surgical incisions to prevent vegetative pathogens

antisepsis

chemical agents are applied to the skin

germicide/microbicide

chemical agents that kill microorganisms

bacteristatic

chemical agents that prevent the growth of bacteria on tissues or on objects in the environment

virucide

chemical known to inactivate viruses, especially on living tissue

fungicide

chemical that can kill fungal spores

bactericide

chemical that destroys bacteria except for those at the endospore stage

tinctures

chemicals dissolved in pure alcohol or water-alcohol mixtures

aqueous solutions

chemicals dissolved in pure water as the solvent

fungistatic

chemicals that inhibit fungal growth

leukopenia

decrease in white blood cell levels

hyaluronidase

digests the ground substance that cements animal cells together

mucinas

digests the protective coating on mucous membranes

hemolysins (Ex. S. aureus, S. pyogenes)

disrupt the membrane of red blood cells to release hemoglobin

kinase

dissolves fibrin clots

filtration

effective method to remove microbes from air and liquids-cellulose acetate, filters, unglazed porcelain, charcoal, plastics

radiation

energy emitted from atomic activities and dispersed at high velocity through matter or space gamma rays, X rays, ultraviolet radiation

exoenzymes

enzymes secreted by microbes that break down and inflict damage on tissues

psychrophiles

grow slowly at freezing temperatures and can secrete toxic products

leukocytosis

increase in white blood cell levels

transmitter

individual or object from which an infection is acquired

nosocomial infections

infections acquired or developed during a hospital stay

point-source epidemic

infectious agent came from a single source, and all of its "victims" were exposed to it from that source

period of invasion

infectious agent multiplies at high levels, exhibits greatest toxicity, becomes well established in host issue

leukocidins (Ex. Streptococcus and Staphylococcus)

kill phagocytes outright;

florence nightingale

laid the foundations of modern epidemiology

endotoxin (lipid A)

lipopolysaccharide (LPS), part of the outer membrane of gram- negative cell walls

sequelae

long-term or permanent damage to tissues or organs cause by infectious diseases

stasis and static

mean "to stand still"

incidence

measures the number of new cases over a certain time period (morbidity rate)

mortality rate

measures the total number of deaths in a population due to a certain disease

endogenous

microbe already existing on or in the body - normal biota or a previously silent infection

exogenous

microbe originating from a source outside the body from the environment or another person or animal

pathogen

microbe whose relationship with its host is parasitic and results in infection and disease

opportunistic pathogens

not considered pathogenic to a normal, healthy person

sign

objective evidence of disease as noted by an observer

sporadic

occasional cases are reported at irregular intervals at random locales

convalescent period

patient begins to respond to the infection and symptoms decline

sanitization/decontamination

physical removal of microorganisms and debris-eating utensils

aseptic techniques

practiced in healthcare; range from sterile methods to antisepsis

reservoir

primary habitat in the natural world from which a pathogen originates

disinfection

procedure or chemical that destroys vegetative pathogens but not spores on non-living surface

adhesion

process by which microbes gain a more stable foothold on host tissues

sterilization

process that destroys or removes all viable microorganisms (viruses)

exotoxins

proteins with a strong specificity for a target cell and extremely powerful, sometimes deadly effects on membrane

lyophilization

pure cultures are frozen instantaneously and exposed to a vacuum that removes water, avoiding the formation of ice crystals

degerming/antisepsis

removal of microorganisms on skin

common-source epidemic

result from common exposure to a single source of infection over a period of time

propagated epidemic

results from an infectious agent that is communicable from person to person and is sustained over time in a population

thermal death time (TDT)

shortest length of time required to kill all test microbes at a specified temperature

commercial sterilization

sterilization plus endospores

epidemiology

study of frequency and distribution of disease and other health-related factors in defined populations

symptom

subjective evidence of disease as sensed by the patient

lymphadentitis

swollen lymph nodes

infectious

synonymous with communicable

edema

the accumulation of fluid in afflicted tissue

etiologic/causative agent

the cause of infection and disease

infectious disease

the disruption of a tissue or organism caused by microbes or their products

index case

the first patient found in an epidemiological investigation

sepsis

the growth of microorganisms in the blood and other tissues

thermal death point (TDP)

the lowest temperature required to kill all microbes in a sample in 10 minutes

infectious dose (ID)

the minimum number of microbes necessary to cause an infection to proceed

portal of entry

the route that a microbe takes to enter the tissues of the body to initiate an infection

incubation period

the time from initial contact with the infectious agent to the appearance of symptoms

prevalence

the total number of existing cases with respect to the entire population

dessication

vegetative cells directly exposed to normal room temperature gradually become dehydrated

granulomas and abscesses

walled-off collections of inflammatory cells and microbes in the tissues

chemical agent in microbial control dissolved in pure H2O 70% alcohol is the best

what are aqueous solutions?

formaldehyde, radiation, ethylene oxide

what are examples of chemical agents that target cellular synthesis

moist heat, alcohol, phenolics

what are examples of chemical agents that target proteins?

detergents

what are examples of chemical agents that target the cell membrane?

chemicals, detergents, alcohol

what are examples of chemical agents that target the cell wall

chemical agent in microbial control dissolved in pure alcohol iodine where: 1% I2 + 70% ethanol = 100% death in 90 seconds

what are tinctures?

effective against: 100% bacteria, fungi, and certain viruses time required for effectiveness: 10 minutes locations/uses: household surfaces; medical settings effect: microbicide; irreversible microbistat Formulations: sprays, liquids, gels, granules etc.

what is disinfectant effective against, required time for effectiveness, locations/uses, effect, and formulations?

effective against: 99.9% of bacteria Time required for effectiveness: 30 sec. -5 minutes Locations/uses: household and food contact surfaces Effect: limited microbicide Formulations: sprays, liquids, gels granules etc.

what is sanitizer effective against, required time for effectiveness, locations/uses, effect, and formulations?

effective against: 100% bacteria, fungi, viruses, spores time required for effectiveness: variable locations/uses: medical instruments; research supplies Effect: microbicide formulations: liquid, gases

what is sterilizer effective against, required time for effectiveness, locations/uses, effect, and formulations?

rapid acting: 10-30 minutes solubility/stability: H2O or alcohol not toxic to humans and animals persistent action: penetration of inanimate surfaces effectiveness: in presence of organic matter

what must one consider when selecting a microbicidal chemical?

epidemic

when statistics indicate that the prevalence of an endemic or sporadic disease is increasing beyond what is expected for a population