Chap 5: Microbiology Basics

Front 1

Disease

Back 1

Failure of the body to function normally

Front 2

Pathogens

Back 2

Disease producing micro-organisms, they are the leading cause of disease in humans

Front 3

Infection

Back 3

The invasion of the body by a pathogen and the symptoms that develop in response to this invasion

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Localized infection

Back 4

an infection that is restricted to a small area

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Systematic infection

Back 5

an infection that is more widespread throughout the body, spreading through the blood

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Colonization

Back 6

The microorganism is present but is not causing an infection. Could become infected later.

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Antibiotic

Back 7

Chemical used to treat bacterial infections. Broad-spectrum used to destroy many different types. Narrow-spectrum only destroys a few types.

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Communicable Disease

Back 8

Any disease that can be spread from one host to another. (ex: chickenpox and measles)

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Non-communicable disease

Back 9

An infectious disease that cannot be transmitted directly or indirectly from host to host.(ex: bladder infection caused by Escherichia coli)

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Commensal

Back 10

Organisms living in a harmonious and beneficial relationship with each other, deriving nutrional or environmental benefits from each other. (*Commensal bacteria is apart of the normal flora*)

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Epidemic Disease

Back 11

A disease acquired by many people in a given area over a short period of time.

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Endemic Disease

Back 12

always present in a population

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Pandemic

Back 13

A worldwide epidemic

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Epidemiology

Back 14

The study of the occurrence and distribution of a disease in a population.

Front 15

Incubation period

Back 15

The lapsed period of time from the exposure of a person to a pathogen to the development of the symptoms of the disease.

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Normal flora

Back 16

A group of microorganism that colonize a host without causing disease. Present in vagina, intestinal tract, mouth, nasal cavities and other parts. Microorganism that aren't pathogenic to one area could become pathogenic to another (ex: bladder infections). The blood, urine and cerebrospinal fluid do not contain normal flora and are therefore sterile.

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Nosocomial infection

Back 17

Hospital acquired infection

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Reservoir of Infection

Back 18

A continual source of infection. Could be (1)living organisms such as humans or animals, (2)non-living substances that are contaminated with the pathogen (ex: used needle) or (3) inanimate ones like soil and water

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Fomite

Back 19

Contaminated nonliving object

Front 20

Resistance

Back 20

The ability to ward of diseases

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Susceptibility

Back 21

A lack of resistance

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Sterilization

Back 22

A process that destroys all living organisms

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Vector

Back 23

A carrier of pathogens from host to host. Ex: mosquito(animal vector), Contaminated syringe(nonliving vector)

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Bacteria

Back 24

Single celled organisms found everywhere. Can perform useful roles (ex:normal flora). Largest group of pathogens.Causes damages by: (1)entering and growing in the human body and (2) secreting toxins that damage the cell.Important characteristics: (1) has a cell wall and (2) the ability to form spores

Front 25

Groups of bacteria

Back 25

grouped by shape. (1)coccus(round), (2)bacillus(rod-shaped) and (3)curved rod. Rickettsiae and chlamydiae are also bacteria (differ in several ways).

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Cocci

Back 26

Round cells that are arranged in pattern. Causes many disease, a few are: gonorrhea, meningitis and pneumonia

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Diplococci

Back 27

cocci arranged in pairs.

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Streptococci

Back 28

cocci arranged in chains like a chain of beads.

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Staphylococci

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Cocci that looks like bunches of grapes and are arranged in clusters

Front 30

Bacili

Back 30

Long and slender and are shaped like a cigar. Causes tetanus, diphtheria and tuberculosis.

Front 31

Vibrio

Back 31

curved rod that has a slight curve and resembles a comma. Causes cholera.

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Spirillum

Back 32

curved rod that is a long cell that coils like a corkscrew

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Spirochete

Back 33

Tightly coiled spirilla that is capable of waving and twisting motions. Most famous one is Treponema pallidum which causes syphilis.

Front 34

Spores

Back 34

allows bacteria to survive harsh environmental conditions such as drying, heating, and exposure to some disinfectants. Enable the bacteria to exist in a dormant state until conditions improve.

Front 35

Rickettsia

Back 35

Smaller than most bacteria and produce within living organisms.Classified as an obligate intracellular parasite due to the fact that it requires that living organism. Often carried by fleas, ticks and body lice.Treated with antibiotics.

Front 36

Parasites

Back 36

microorganisms that require a living host

Front 37

Chlamydiae

Back 37

Smaller than the rickettsiae. Causes several important human diseases such as the US most common std, Chylamydia. Chylamydial infections cause trachoma, an eye infection that is the worlds leading cause of blindness. Treated with antibiotics

Front 38

Viruses

Back 38

Smallest of the infectious agents. They are't cell and consists of DNA or RNA surrounded by a protein shell. They can only reproduce in a living organism. Classified as a parasite. Ex: Influenza, measles, mumps and AIDS.

Front 39

Fungus

Back 39

Plantlike organism(yeast and mold) that grows best in dark damp places. Systematic fungal infections are rare, life threatening and difficult to cure.

Front 40

Mycotic Infections

Back 40

Caused by pathogenic fungi and are usually localized. Includes: athletes foot, ringworm, thrush and vaginitis.

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Protozoa

Back 41

Single celled, animal like microbes. There are four types: (1)amebas, (2)ciliates, (3)flagellates and (4)sposozoa. They are found in soil and most bodies of water. Malaria is caused by a sporozoan.

Front 42

Parasitic worms

Back 42

(Also called Helminths ) are multicellular animals that are parasitic and pathogenic to humans. Identification of a worm infestations requires microscopic examination of body samples (i.e: stool), which usually reveals adult worms or larval forms. Two types:(1)roundworm or (2)flatworm. Infestations are treated with anthelmintics.

Front 43

Fecal-Oral route

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Hands contaminated by feces introduced the worms, eggs or larvae into the mouth. Most worm infestations are transmitted via this route

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Arthropods

Back 44

Animals with joint legs and include insects.Two types: (1)ectoparasites, mites and lice that live on the surface of the body, skin and mucous membrane. They cause itching and discomfort but are not life threatening. (2) Mosquitoes, biting flies, fleas and ticks act as a vector of disease by biting the host and transferring the pathogen

Front 45

Host

Back 45

Person or organism that is infected by a pathogen

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Staining

Back 46

A Lab test used to identify pathogens.Important first step in identifying causative organism of an infection. A gram-positive bacterium is one that picks up a purple or blue stain (not deadly and are treatable with antibiotics). A gram-negative bacterium is one that picks up a pink or red stain (usually deadly are is not always treatable with antibiotics)

Front 47

Culture

Back 47

The growth of pathogens in a culture medium.

Front 48

Acid-Fast Stain

Back 48

A lab test in which the bacteria is first stained with red dye and then washed with acid and the bacteria that retains the red stain is called acid-fast. (I.E: the causative organism of TB, tuberculosis)

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Culture medium

Back 49

food that supports the growth of pathogens

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Portals of entry

Back 50

How pathogens enter the body.Respiratory and gastrointestinal are most common. Also through the genitourinary tracts, eye, skin and parenteral route(injuries that penetrate the skin or mucous membrane; bites, cuts, surgeries).

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Portals of exit

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How pathogens get out of the body. Respiratory and gastrointestinal are most common. Also through the genitourinary tracts, eye, skin and breast (milk)

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How pathogens spread

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(1)Person--person
(2)Environment--person
(3)insects--persons

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Biological vector

Back 53

a living vector in which the pathogen requires to complete its life cycle. (ex: a mosquito bites a person with malaria, the plasmodium (causative organism of malaria) matures in the stomach of the mosquito. The mosquito bites another person and the plasmodium is then transferred to that person causing malaria)

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mechanical vector

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Spreading of germs (ex: fly then hops from dog feces and carries the germs on its feet to food on a picnic table)

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Superinfection

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Organisms that do not cause disease in there normal habitat but become pathogenic when allowed to over populate.

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Zoonosis

Back 56

An animal disease that is transmittable to humans. Ex: malaria, rocky mountain spotted fever(RMSF) and endemic typhus