Test Questions on Micro test 3 – Flashcards
Unlock all answers in this set
Unlock answersPathology |
The study of disease |
Etiology |
The study of the cause of a disease. |
Pathogenesis |
The development of disease |
Infection |
Colonization of the body by pathogens |
Disease |
An abnormal state in which the body is not functioning normally |
Normal microbiota or normal flora |
The microorganisms that establish more or less permanent residence (colonize) but tht do not produce disease under normal conditions. permanently colonize the host. |
Transient Microbiota |
May be present for several days, weeks, or months and then disappear. |
Symbiosis |
is the relationship between normal microbiota and the host. (Fungi and Algea) |
commensalism |
In the symbiotic relationship called ___ one organism benefits, and the other is unaffected. |
mutualism |
both organisms benefit. Ex. E. coli is produced by the large intestine. E. coli produces vit K and B which is absorbed by the blood. |
parasitism |
one organism benefits by deriving nutrients at the expense of the other. |
opportunistic pathogens |
Some normal microbiota are called ___. They do not cause disease in their normal habitat. Ex. E.coli outside of the large intestine. |
Microbial antagonism |
is a competition between microbes. One consequence of this competition is that hthe normal microbioa protexr the host against colonization by potenially pathogenic microbes by competing for nutrients, producing substances harmful to the invading microbs, and affexring conditions such as pH and avaiable oxygen. |
Normal microbiota |
_________protect the host by -Occupying niches that pathogens might occupy -Producing acids -Producing bacteriocins |
Probiotics |
Live microbes applied to or ingested into the body, intended to exert a beneficial effect |
Koch’s Postulates |
1.The same pathogen must be present in every case of the disease 2.The pathogen must be isolated from the diseases host and grown in pure culture 3.The pathogen from the pure culture must cause the disease when it is inoculated into a healthy, susceptible lab animal 4.The pathogen must be isolated from the inoculated animal and must be shown to be the original animal |
Koch's postulates |
____ are used to prove the cause of an infectious disease.;Some pathogens can cause several disease conditions.;Some pathogens cause disease only in humans |
-Symptom ; ; ; |
__ A change in body function that is felt by a patient as a result of disease |
Syndrome |
___A specific group of signs and symptoms that accompany a disease |
Sign |
;__ A change in a body that can be measured or observed as a result of disease |
Communicable disease |
;A disease that is spread from one host to another |
Contagious disease |
;A disease that is easily spread from one host to another |
Noncommunicable;disease |
;A disease that is not transmitted from one host to another |
Incidence |
Fraction of a population that contracts a disease during a specific time |
Prevalence |
;Fraction of a population having a specific disease at a given time |
Sporadic disease:; |
Disease that occurs occasionally in a population |
;Endemic disease:; |
Disease constantly present in a population
|
Epidemic disease: |
Disease acquired by many hosts in a given area in a short time |
Pandemic disease: |
Worldwide epidemic |
Herd immunity: |
Immunity in most of a population |
Acute disease: |
Symptoms develop rapidly |
Chronic disease: |
Disease develops slowly |
Subacute disease: |
Symptoms between acute and chronic |
Latent disease: |
Disease with a period of no symptoms when the causative agent is inactive |
Local infection |
: Pathogens are limited to a small area of the body |
Systemic infection: |
An infection throughout the body |
Focal infection: |
Systemic infection that began as a local infection |
Sepsis: |
Toxic inflammatory condition arising from the spread of microbes, especially bacteria or their toxins, from a focus of infection
|
Bacteremia: |
Bacteria in the blood |
Septicemia: |
Growth of bacteria in the blood |
Toxemia:
|
___Toxins in the blood ___ Viruses in the blood |
Primary infection: |
Acute infection that causes the initial illness |
Secondary infection: |
Opportunistic infection after a primary (predisposing) infection |
Subclinical disease: |
No noticeable signs or symptoms (inapparent infection) |
§Short urethra in females §Inherited traits, such as the sickle cell gene §Climate and weather §Fatigue §Age §Lifestyle §Chemotherapy |
Predisposing Factors that make the body more susceptible to disease and may alter the course of the disease: ___, ___,___,___,___,___,___. |
Reservoirs of Infection |
For a disease to perpetuate itself, there must be a continual source of the disease organisms.This object provides a pathogen with adequate conditions for survival. |
Carriers |
These ppl are important living reservoirs of infection. They also play an important rolein the spread of diseases such as AIDS or gonorrhea. |
zoonoses |
Some diseases carried by animals like Rabies and Lyme disease may be transmitted to humans |
Soil, water |
The 2 major nonliving reservoirs of infectious disease are __ and __. Can cause botulism or tetanus. |
-Direct contact transmission -Indirect contact transmission
|
___Requires close association between infected and susceptible host. __Spread by fomites. ___ Transmission via airborne droplets. |
Vectors |
___ are animals that carry pathogens from one host to another. Ex. Arthropods, especially fleas, ticks, and mosquitoes |
Mechanical transmission: |
Vectors Transmit disease by 2 general methods: ___-Arthropod carries pathogen on feet ___-Pathogen reproduces in vector |
Nosocomial Infections |
__ is one that doesn’t show any evidence of being present at the time of admission to a hospital. Usually acquired as a result of a hospital stay. Affect 5–15% of all hospital patients. |
Emerging Infectious Diseases |
Diseases that are new, increasing in incidence, or showing a potential to increase in the near future. |
- Genetic recombination |
A variety of factors contribute to the emergence of new infectious diseases. E. coli O157, avian influenza (H5N1) is an example of __. V. cholerae O139 is an example of __. Inappropriate use of antibiotics and pesticides create__. Changes in weather patterns may increase the distribution and survival of reservoirs and vectors. Ex. Hantavirus |
-West Nile Virus -Coccidioidomycosis - Lyme disease |
Emerging Infectious Diseases: ___ may spread o new geographic areas by modern transportation. Ecological disaster, war, and expanding human settlement can cause __. Even animal control measures may increase the incidence of a disease like __.Failures in public health measures may spread __.
|
Epidemiology |
|
Centers for Disease Control and Prevention (CDC) |
Collects and analyzes epidemiological information in the United States and published Morbidity and Mortality Weekly Report (MMWR). |
John Snow |
Mapped the occurrence of cholera in London. |
Ignaz Semmelweis |
Showed that handwashing decreased the incidence of puerperal fever |
Florence Nightingale |
Showed that improved sanitation decreased the incidence of epidemic typhus. |
Descriptive Epidemiology: (snow) |
Collection and analysis of data (Snow). |
Analytical Epidemiology: (Nightingale) |
Comparison of a diseased group and a healthy group (Nightingale). |
Experimental Epidemiology: |
Controlled experiments (Semmelweis). |
Case reporting: |
Health care workers report specified disease to local, state, and national offices |
Nationally notifiable diseases: |
Physicians are required to report occurrence. |
Morbidity: Mortality: Morbidity rate: Mortality rate: |
The CDC issues a publication called the published Morbidity and Mortality Weekly Report (MMWR) which contains data on ___ Incidence of a specific notifiable disease. ___ Deaths from notifiable diseases. __Number of people affected in relation to the total population in a given time period. __Number of deaths from a disease in relation to the population in a given time |
Pathogenicity: Virulence: |
___-The ability to cause disease.
___-The extent of pathogenicity. This depends on certain factors such as adherence adn cell wall structure. |
Adhesins/ligands |
__ from pathogens bind to receptors on host cells. Ex. Glycocalyx: Streptococcus mutans Fimbriae: Escherichia coli M protein: Streptococcus pyogenes Form biofilms |
Capsules |
Streptococcus pneumoniae, Haemophilus influenzae, Bacillus anthracis have ___ which prevent phagocytosis. |
M protein Opa protein Mycolic acid |
The cell walls of certain bacteria contains chemical substances that contribute to virulence. Streptococcus pyogenes produces ___ that resists phagocyosis. Neisseria gonorrhoeae produces __ that inhibits T helper cells. Mycobacterium tuberculosis produce __ which makes up the cell wall and resist digestion by phagocytes. |
Coagulase Kinases |
___ are bacterial enzymes that coagulates fibrinogen in blood. ____ an enzyme that digest fibrin clots in blood. ***
|
Hyaluronidase |
|
Collagenase IgA proteases |
|
Portals of entry |
Pathogens can gain enrance to the human body and other hosts through several avenues called __ where they penetrate tissue and cause structural damage. The occurrence of disease depends on several factors, one of which is the__. Ex. moucous membranes, skin, parenteral route, preferred portal of entry. |
Mucous Membranes |
Many bac. gain access to the body by prenetrating the __ lining the gastrointestinal tract (polio, typhoid fever), genitourinary tract (syphilis), or the respiratory tract (TB, measles) which is the easiest and most frequently travled portal of entry. |
-Skin
-parenteral route |
Other portals of entry: __-physical barrier. Some microbes gain access to the body when they are directly deposited into the tissue benathe the skin, this route is called __. |
ID50 |
The virulence (degree of pathogenicty) of a microbe is often expressed as ___ (Infectious dose for 50% of the test population). The potency of a toxin is often expressed as the ___Lethal dose (of a toxin) for 50% of the test population. |
- G+ spore
- G+ cocci |
Botulinum is _ and has a LD50 of 0.03 ng/kg for mice.
|
Actin |
A major compenen of the cytoskeleton is a protein called __, which is used by some microbes to penetrate host celss and by others to move through and btw host cells. |
Invasins |
Once microbes make contact with the hot cell plasma membranes, the microbes produce surface proteins called __ that rearrange nearby actin filaments of the cytoskeleton. Ex.Salmonella alters host actin to enter a host cell.
|
Listeria |
Once inside the host cell, certain bac. such as __ use actin to move from one cell to the next. |
- disrupt host cell function
- producing toxins. |
When pathogens overcome the host's defense, the microbes can damage the host's cell by: ___, producing waste products, and ___. |
-Toxins -Toxigenicity |
__ are poisonous substance that contributes to pathogenicity . The ability to produce a toxins ___. |
-Toxemia: |
Presence of toxin in the host's blood is __. |
-Antitoxin -Toxoid |
The body produces anitbodies against a specific toxin called __. __ are inactivated toxins used in vaccines to stimulate antitoxin production in the body so that immunity is produced. |
Exotoxin |
a protein produced inside some bacteria and are among the most letha substances known. (G+ rod, cocci). |
Membrane-disrupting toxins |
__ Lyse host’s cells by making protein channels in the plasma membrane and disrupting phospholipid bilayer.Leukocidins kill phagocytic lekocytes. Hemolysins distroy erythrocytes. Streptolysins. |
Superantigens |
Cause an intense immune response due to release of cytokines from host cells.Symptoms: fever, nausea, vomiting, diarrhea, shock, endotoxic shock, and death. |
-Fusarium
|
Fungal waste products may cause symptoms and chronic infections provoke an allergic response. Tichothecene toxins inhibit protein synthesis in eukaryotic cells and produce ___. Two fungi that cause skin infection are Candida and Trichophyton and they produce __. __ produce capsule prevents phagocytosis. |
-Sepsis -Asepsis |
__refers to microbial contamination. __ is the absence of significant contamination. Aseptic surgery techniques prevent microbial contamination of wounds |
Sterilization
-Commercial sterilization |
__Removing all microbial life. __ is a limited heat treatment used to kill C. botulinumendospores in can foods. Disinfection: is removing pathogens. __ is removing pathogens from living tissue.
|
Sanitization: Bacteriostasis: |
Degerming is removing microbes from a limited area. __ is Lowering microbial counts on eating utensils. Biocide/germicide: Kills microbes. __ inhibiting, not killing, microbes. |
Thermal death point (TDP): |
Lowest temperature at which all cells in a culture are killed in 10 min. |
Thermal death time (TDT): |
(minimal) Time during which all cells in a culture are killed. |
Deciaml reduction time (DRT) or D value |
The time in minutes in which 90% of th population of bacteria at a given temperature will be killed. |
Autoclave: Steam under pressure |
Moist heat denatures proteins. The high temps. are most commonly achieved by steam under pressure in __. (Sterilation takes place at 121C for 15 min) |
Pasturization |
__ Reduces spoliage organisms and pathogens. It's not considered sterile because thermoduric bac survive but are unlikely to causes diseases. Invited by Louis Pasteur. |
High-temperature short-time:
|
Classic pasteruization treatment of milk was 63°C for 30 min. Today __ is used to sterilize milk 72°C for 15 sec. __ is used so milk does not need refrigeration140°C for <1 sec. |
fractional sterilization or tyndallization |
is when material is exposed to free flowing steam for 30 min on each side for 3 consecutive days. |
Dry heat sterilization |
__ Kills by oxidation. Examples of sterilization: Dry heat, Flaming, Incineration, and Hot-air sterilization (items to be sterilized are placed in a oven at 170 C for 2 hours). |
-HEPA -Membrane filtration |
Filtration methods are used to sterilize heat-sensitive materials. __ removes microbes > 0.3µm. __ removes microbes > .22µm. |
Low temperature Desiccation |
__ inhibits microbial growth: Refrigeration, Deep-freezing, Lyophilization. High pressure denatures proteins. __ prevents metabolism. Osmotic pressure causes plasmolysis. |
-Ionizing radiation -Nonionizing radiation -Microwaves |
__ (X rays, gamma rays, electron beams) Ionizes water to release OH• Damages DNA. ___ (UV, 260 nm) Damages DNA. __kill by heat; not especially antimicrobial. |