Microbiology chapters 23 and 24 review

portals of entry and exit

1. the skin and mucous membranes 2. the respiratory tract 3. the digestive tract 4. the genitourinary tract 5. the placenta

primary infection

An acute infection that causes the initial illness

Zoonosis

An infectious disease that is transmissible from animals to humans.

vectors

An organism that transmits disease by conveying pathogens from one host to another

Iodine

Controls microbial growth by oxidizing certain molecules within the microbial cell, can be used in the form of either a tincture or aniodophore. A tincture is a solution of this and alcohol that is primarily used as an antiseptic.

general infection

If the infection becomes systemic

endogenous infection

Infections caused by bacteria that are normally nonpathogenic and that normally inhabit the digestive tract

secondary infection

Once the primary infection weakens the host, another infection caused by a different organism can develop.

physical method 1

Scrubbing is a manual process by which microorganisms are removed from a surface.

pathogenicity

The ability of the microorganism to survive

antigens

The body recognizes cells by certain characteristics of the cell

bacteremia

The presence of bacteria in the blood

viremia

The presence of viruses in the blood

indirect contact

The result of an individual coming in contact with inanimate objects. The primary mechanisms are food, water, air, and zoonoses.

Physical method 3

Ultraviolet (UV) light is a form of nonionizing radiation that can effectively control the growth of microorganisms placed directly in its path. • It inhibits microbial growth by damaging the cell's genetic material. • When exposed directly to UV light, some microorganisms develop bonds between adjacent thymines in their DNA. • The sun contains UV light; however, much of it is filtered by the Earth's ozone and never reaches the surface in a form that kills microorganisms. • For UV light to be effective, the microorganism must be exposed to it directly. • Even paper prevents UV light from penetrating enough to kill microorganisms, and many microorganisms contain pigments resistant to the detrimental effects of UV light.

endotoxin

a bacterial toxin confined within the body of a bacterium that is released only when the bacterium is actively dividing or being broken down

exotoxin

a toxin, generally a protein, produced by a microorganism and excreted into its surrounding medium

Resistance

ability of the human to defend against the pathogen

natural passive

acquired by a child through placenta and breast milk

pandemic diseases

affect the majority of the population of a large region or are epidemic at the same time in many different parts of the world.

Chemical antimicrobial

agents fall into one of two broad categories based on their suffix.

the suffix -cide

agents that will kill a particular type of microorganism

Aldehydes

are a group of organic compounds that control microbial growth by reacting with the proteins in microorganisms and altering their chemical structure.

Fomites

are any inanimate objects to which infectious material adheres and can be transmitted.

Epidemic diseases

are diseases that attack many people at the same time in the same geographic region

Communicable diseases

are those diseases that may be transmitted directly or indirectly from one individual to another.

Halogens

are widely used disinfectants that work by oxidizing the components of microbial cells. Some halogens also react with cellular proteins.

mixed infection

caused by two or more organisms

Glutaraldehyde (C5H8O2)

cold sterilization

Septicemia

commonly known as blood poisoning, occurs when the bacteria or its products are present in the blood.

noncommunicable diseases

do not spread from one person to another

Natural active

immunity is the result of developing a disease and recovering from it

Artificial passive

immunity is the result of the injection of antibodies in the form of immune (convalescent) serums

direct transmission

include physical contact, droplet infection, and congenital transmission. typically, person-to-person contact through casual or intimate contact.

exogenous

infections caused by organisms not present in the body

local infection

is caused by microorganisms lodging and multiplying at one point in a tissue and remaining in that tissue. (stays in one spot)

Toxemia

is the distribution throughout the body of poisonous products of bacteria growing in a focal or local site, thus producing generalized symptoms, which may include fever, diarrhea, vomiting, either an increase or decrease in pulse and respiration, and eventually shock and death.

Sanitization

is the reduction of the microbial population to a safe level as determined by public health standards. There are both physical and chemical methods of controlling microbial growth.

Infection

is the state or condition in which the body or a part of the body is invaded by a pathogenic agent that, under favorable conditions, multiplies and produces injurious effects.

Chlorine

is used to treat municipal drinking water and for the maintenance of swimming pools. Actually a gas, so it is often combined with water to form sodium hypochlorite.

Endemic diseases

occur continuously in a particular region but usually have a low mortality.

Sporadic diseases

occur occasionally or in scattered instances within a geographic region.

Sterilization

offers the highest level of microbial growth control. It is the process of completely removing or destroying all life-forms, including bacterial endospores.

focal infection

one in which the organisms are originally confined to one area but enter the blood or lymph vessels and spread to other parts of the body (likes to have fun and move around)

the suffix -static

prevent the growth of a particular type of microorganism.

Universal Precautions

steps taken to prevent the spread of disease through blood and other body fluids when providing first aid or health care

reservoirs

the natural habitat of a disease-causing organism.

Antisepsis

the process by which microbial growth is inhibited on living tissue to prevent infection. Disinfectants are applied to inanimate objects, while these are applied to living tissue. Sanitization is the reduction of the microbial population to a safe level as determined by public health standards. There are both physical and chemical methods of controlling microbial growth.

Disinfection

the reduction of pathogenic agents by chemical or physical means by applying the disinfectant to an inanimate object. Offers less control of the growth of microorganisms. The process does not inactivate microbial endospores; however, it does kill most vegetative microorganisms. The number of microorganisms is reduced to the point that they no longer present a serious health hazard.

virulence

the relative power and degree of pathogenicity possessed by organisms to produce disease,

artificial active

vaccinations

formaldehyde (CH20)

was used to prepare the poliovirus vaccine causing many people to contract the disease because the concentration was not sufficient to produce a safe vaccine.

Antibodies

which are also known as immunoglobulins, are glycoprotein substances produced by the body in response to specific antigens.

nonhuman animal reservoirs

• Both Campylobacter and Salmonella are bacteria found in infected poultry. • Rabies, which is caused by a virus, is another disease that is found in wildlife such as foxes, raccoons, skunks, rabbits, bats, mice, chipmunks, squirrels, and even cattle. • Even the innocent-looking prairie dog is host to the deadly bacterium Yersinia pestis that causes plague.

Factors that influence the effectiveness of antimicrobial agents used to control microbial growth.

• Nature of the disinfectant • Concentration of the disinfectant • Nature of the material to be disinfected • Number of microorganisms present • Type of microorganism present • Length of exposure to disinfectant • Temperature of the disinfectant during exposure • Disinfectant's pH during exposure

Factors Influencing the Virulence of Microorganisms

• ability to produce enzymes that damage human tissues. • Hyaluronidase, fibrinolysin, and coagulase are enzymes that can be used by certain bacteria to better use blood as a nutrient source, which results in disease in the infected human. • Microorganisms that contain a capsule or that can produce endospores

Environmental reservoirs

• largely found in water and soil. • Clostridium botulinum, which causes botulism, and C. tetani, which causes tetanus, are both widespread in soils. • A more recently discovered disease, Legionnaires' disease, is transmitted by contact with amebas in contaminated water found in air conditioning units on buildings.

human reservoirs

• some of the easiest to control. • In some cases, the pathogen can also spread through animal reservoirs, or even the environment. • The disease can often be controlled through programs aimed at its elimination.

phenolic

•Compounds include phenol (carbolic acid), cresols (lysol), and hexachlorophene. • Control microbial growth by denaturing proteins and disrupting cell membranes. • In most cases, they are not effective in killing bacterial endospores, so they do not make good sterilants.

Alcohols

•INTERMEDIATE-LEVEL DISINFECTION •Widely used disinfectants that control microbial growth by denaturing proteins and by dissolving lipids in the cell membrane of microorganisms. • They are most effective in aqueous solution because proteins are not soluble in high concentrations.

Physical method 2

•Temperature can be used to control the growth of microorganisms by incineration, dry heat, and moist heat, which are forms of boiling, free- flowing steam, and steam under pressure, respectively. • Heat kills microorganisms by denaturing the proteins they contain, and proteins are denatured more easily when they are wet. • The opposite extreme to heat, which is cold, can also be an effective means of controlling microbial growth.

Phenol

•is slightly acidic and is also known as carbolic acid. • It has a sickeningly sweet and tarry odor and is available commercially as a liquid. • flammable, and skin exposure has been shown to cause chemical burns, liver damage, diarrhea, dark urine, and hemolytic anemia. • Breathed into the lungs when smoking tobacco. • Due to its toxic nature derivatives have replaced it as a disinfectant and antiseptic.