Shared Flashcard Set

Details

Microbiology
Chapter 8-12
110
Nursing
Undergraduate 3
02/10/2012

Additional Nursing Flashcards

 


 

Cards

Term
desiccation
Definition
drying out of cysts and spores
Term
water
Definition
needed to carry out metabolic processes
Term
things that affect microbial growth
Definition
temperature, nutrient availability, moisture, pH (7.0-7.4), osmotic pressure & salinity, barometric pressure, gases
Term
thermophiles
Definition
bacteria who grow best at high tempertures
Term
psychrophiles
Definition

bacteria that prefer cold temps

refridgerator temp 4C

thrive in cold ocean water

Term
psychroduric
Definition
organisms  that prefer warmer temps but can survive through very cold temps and be preserved in a frozen state ex-E. coli
Term
alkaliphiles
Definition

pH >8.5

ex environment in SI

Term
acidophiles
Definition

pH 2-5

live in stomach

Term
hypotonic
Definition
less solute outside of cell than inside, cell swells and may lyse
Term
plasmoptysis
Definition
escape of cytoplasm from ruptured cell
Term
hypertonic
Definition
more solute outside of the cell than inside, cell shrivels (crenate)
Term
halophiles
Definition
organisms that thrive at high salt concentrations
Term
haloduric
Definition
can tolerate salty environments
Term
microaerophiles
Definition
reduced concentration of oxygen ~5%
Term
piezophiles
Definition
bacteria or archaea grow at high pressures ex: deep in the ocean
Term
to culture bacteria in the lab (in vitro) need proper:
Definition
nutrients, atmosphere, temperature
Term
nutrients are provided by medium:
Definition

may be liquid (broth, in tube) or solid (mixed with agar, petri dish)

may be chemically defined-exact chemical components known or complex-made with part of extracts of animals, yeast, plants. exact chemicals not known

Term
enriched medium
Definition
contains a rich supply of special nutrients to promote the growth of fastidious microorganisms
Term
selective medium
Definition

contains ingredients that inhibit the growth of some organsims but allow the growth of others

ex: MacConky agar inhibits growth of gram pos bacteria

Term
differential medium
Definition
causes different species of bacteria growing on it to have a different appearance so you can tell them apart
Term
steps to culturing microorganism in the lab
Definition

inoculation-adding microorganisms to a tube or plate of medium

incubation- put inoculated specimen in favorable temp & atmosphere. wait for bacteria to grow

pure culture- tube or plate containing only one kind of microorganism

Term
3 types of incubators
Definition

CO2 incubators, 5-10%CO2

non-CO2 incubator, room air

anaerobic incubator, devoid of oxygen

Term
stages of bacterial growth in vitro
Definition

lag phase- bacteria absorb nutrients, synthesize enzymes, don't replicate

logarithmic growth phase- bacteria multiply rapidly, # cells double with each generation time

sationary phase- nutrients start to run out, waste products build up, growth slow down & equals rate of death

death/decline phase- bacteria die at rapid rate, some may form endospores

Term
chemostat
Definition
regulates the supply of nutrients & the removal of waste products & excess microorganisms
Term
how to count number of bacteria in a sample of liquid
Definition

if there's a lot, measure light absorbance with spectrophotometer

or, make dilutions of the sample and inoculate plates or solid medium w/specified volume of sample dilution

incubate

count # of colonies on the plate and multiply by dilution factor

Term
culturing obligate intracellular pathogens
Definition
mediums of growth: embryonated chicken eggs, lab animals, cell cultures
Term
culturing fungi
Definition

no single medium cluture best for growing fungi

media often contains antibiotics to inhibit bacterial growth and/or are acidic-also inhibits bacterial growth

some fungi are highly infectious

 

Term
sterilization
Definition
completely inhibits all microbial life, including spores
Term
disinfection
Definition
eliminate most or all pathogens, except spores, from nonliving objects
Term
pasteurization
Definition
method for disinfecting liquids by heating
Term
disinfectants
Definition
chemicals used to disinfect inanimate objects
Term
antiseptics
Definition
chemicals used to disinfect living tissue
Term
sanitization
Definition
reduction of microbial populations to safe public health levels
Term
-static
Definition
indicates an agent that inhibits growth, but doesn't kill
Term
sepsis
Definition
presence of pathogens in blood or tissue
Term
asepsis
Definition
absense of pathogens
Term
antisepsis
Definition
prevention of infection
Term
antiseptic technique
Definition

use of antiseptic agent to prevent infection

developed by Joseph Lister in 1867

Term
sterile technique
Definition
techniques for eliminating all microorganisms from an area ex:an OR
Term
physical method of inhibiting microbe growth: heat
Definition

practical, efficient, inexpensive

effectiveness depends on time and temp

thermal death point (TDP)-lowest temp that will kill all organisms in pure culture within a specified time

thermal death time (TDT)-lenght of time necessary to sterilize a pure culture at specified temp

Term
dry heat
Definition

160-165C for 2hrs or 180C for 1hr

heat must thoroughly penetrate material

moist or protein-laden materials can decrease effectiveness

Term
moist heat
Definition

boiling for 30min kills vegetative forms of most pathogens but not endospores

autoclaving at pressure of 15psi at 121.5C for 20 min destroys vegetative microorganisms, bacterial endospores, viruses

Term
cold as inhibitor to microbial growth
Definition
most organisms not killed, metabolic activities are slowed
Term
desiccation
Definition
may remain viable, but cannot reproduce
Term
lyophilization
Definition

cold and desiccation

ex:freeze-drying

Term
radiation
Definition

used to reduce microbes in the air

UV rays cause DNA damage

also prevents food spoilage, sterilization of heat-sensitive surgical equiptment

Term
ultrasonic waves
Definition
clean, not sterilize, equiptment
Term
filters
Definition
seperate cells/microbes from liquids or gases
Term
factors influencing disinfectant effectiveness
Definition

prior cleaning of surface

organic load

bioburden (type & # of microbes)

concentration of disinfectant

contact time

surface texture

temp & pH

Term
commonly used disinfectants
Definition

soap, detergent

alcohols, phenols

halogens

hydrogen peroxide

heavy metal salts

formaldehyde, ethylene oxide

Term
how disinfectants kill
Definition

enzyme inactivation (peroxide, halogens)

cell membrane damage (soap, detergent)

DNA damage (formalin)

Term
phenol coefficient
Definition
measure the effectiveness of a disinfectant compared to phenol
Term
chemotherapy
Definition
use of any chemical to treat any disease
Term
antimicrobial agent
Definition
any chemical used to treat an infectious disease in vitro
Term
antibiotic
Definition
compound produced by a microorganism that kills/inhibits other microorganisms
Term
mechanisms of antibiotic agents
Definition

inhibit cell wall synthesis

damage cell membranes

inhibit nucleic acid (DNA/RNA) synthesis

inhibit protien synthesis

inhibit enzyme activity

Term
broad-spectrum antibiotics
Definition
kill/inhibit both gram-positive and gram-negative organisms
Term
narrow-spectrum antibiotics
Definition
kill/inhibit either gram-negative or gram-positive
Term
sulfonamide drugs
Definition

competative inhibitors

compete with folic acid, without folic acid bacteria cannot produce some essential protients

Term
penicillins & cephalosporins
Definition

bactericidal

cell wall synthesis

Term
tetracyclines
Definition

bacteriostatic

target bacterial ribosomes, inhibit protien synthesis

Term
aminoglycosides
Definition

bactericidal

inhibit protein synthesis, effective agent against many aerobic gram-neg bacteria

Term
macrolides
Definition

eg. erythromycin

bacteriostatic at lower doses, bactericidal at high

protein synthesis

Term
fluoroquinolones
Definition

eg. ciprofloxacin

bactericidal, inhibit DNA snythesis

Term
antifungal & antiprotozoal agents
Definition

difficult to target because they are eukaryotic organisms

interfere with cell membrane sterols or block mitosis/nucleic acid synthesis

Term
antivirals
Definition

tricky because of replication in host cell

interferes with reproduction

Term

superbugs

MRSA

Definition

methicillin-resistant Staphoylococcus aureus (MRSA)

still susceptible of vacomycin

vancomycin-resistant strains (VISA, VRSA)

 

Term

superbugs

VRE

Definition

vancomycin-resistant Enterococcus sppe. 

common UTI

Term

superbugs

TB

Definition

multidrug-resistant Mycobacterium tuberculosos (MDR-TB)

resistant to first-line drugs

XDR-TB: also resistant to second-line drugs

some strains resistant to all drugs

Term
intrinsic drug resistance
Definition

lack specific target of antibiotic

unable to cross cell wall/membrane

 

Term
acquired drug resistance
Definition

if bacteria was once susceptible

changes in drug-binding sites, cell membrane permeability

produce drug destroying-enzyme

pump drug out of cell before it can cause damage

Term
ways of introducing exogenous DNA into a cell
Definition

trasformation-cell absorbs DNA from environment

transduction-carry across from bacteriophages

conjugation-most common method

Term

undesirable effects of antimicrobials

toxicity

Definition

chloramphenicol- aplastic anemia

steptomycin- deafness

Term
sterile tissues in the body
Definition
blood, lymph, spinal fluid, most internal tissues and organs
Term
microflora of the skin
Definition

primarily anaerobic bacteria and fungi

staphylococcus spp. most common

# and type depend on: moisture, pH, temp, salinity, presence of chem wastes & other microbes

Term
microflora of ears and eyes
Definition

middle & inner ear usually sterile

outer ear, same as skin

sparse on eye

Term
microflora of respiratory tract
Definition

upper (nasal passages & throat)- abundant

lower (larynx, trachea, bronchi, lungs)- sterile

Term
microflora of oral cavity
Definition

numerous anaerobic & aerobic bacteria

cause: dental caries, gingivitis, periodontitis

Term
microflora of GI tract
Definition

stomach-low pH-Helicobacter pylori

proximal SI-sterile (bile)

colon- 500-600 mostly obligate, aerotolerant, facultative anaerobes, many are opportunists

Term
microflora of the genitourinary tract
Definition

kindeys, ureters, bladder usually sterile

distal urethra-UTIs (E.coli)

 

sexual transmission-Chlamydia trachomatis, Neisseria gonorrhoeae, mycoplasmas

 

Term
transient colonization
Definition

of skin, mucus memebranes, GI tract

population of microbes that temporarily joins the endogenous microflora

removed by washing, skin sloughing, or find conditions uncongenial or out-competed by other microbes

Term
microbial ecology
Definition
study of interrelationships between microbes and the world around them
Term
biofilms
Definition

form on urinary catheters & medical equipment

cause disease-endocarditis, dental caries, cystic fibrosis, kidney stones, middle ear infections

Term
symbiosis
Definition
two dissimilar organisms lving in close association
Term
neutralism
Definition
neither symbiont affected
Term
commensalism
Definition
beneficial to one, no consequence to the other
Term
mutualism
Definition
beneficial to both
Term
parasitism
Definition

beneficial to one and detrimental to the other

ecto-surface of host

endo-inside of the host

Term
epidemiology
Definition

study of disease

frequency, distribution, determinates develop ways to prevent, control, or eradicate diseases

Term
communicable
Definition

possible to spread, may not be easy

gonorrhea

Term
contagious
Definition

spreads easily from person to person

flu

Term
incidence (morbidity)
Definition

number of NEW cases of disease during a specific time period

period prevalence-# of cases existing in a population during a specified time period

point prevalence- # of cases existing at a particular moment in time

Term
endemic
Definition

always present

TB, STDs, common cold

Term
epidemic
Definition
any increase of disease above normal
Term
zoonoses
Definition
animals are resevoir
Term
vectors
Definition
anthropods involved in transmission 
Term
inanimate reservoirs
Definition
air, soil, dust, contaminated water, food, formites
Term
formites
Definition
inanimate object on which pathogens cal live and by which they can be transmitted
Term
considered potable
Definition

1 coliform or less per 100ml water

acceptable amout of bacteria in water

Term
modes of transmission
Definition

direct skin-to-skin

direct mucus membrane to mucus membrane

indirect: airborne or droplet, food or water, formites

transfusion, contaminated blood/needle

Term
breaking chain of infection
Definition

eliminate or contain reservoir

prevent contact and exit pathway

eliminate means of transmission

block entryway

reduce susceptibility of new host (vaccine)

Term
most common types of HAIs
Definition

UTIs- 13% HAI deaths

surgical site 8%

lower respiratory (pneumonia) 36%

bloodstream (septicemia) 31%

Term
C. difficile associated diseases
Definition

AAD- antibiotic associated diarrhea, caused by enterotoxin

PMC- pseudomembranous colitis, caused by C.diff cytotoxin. lining of colon sloughs off resulting in bloody stool

Term
pt most liketly to develop HAIs
Definition

elderly

women in labor & delivery

premature infants & newborns

surgical & burn pt

diabetic & cancer pt

pt receiving steroids, anticancer drugs, antilymphocyte serum, radiation

innumosuppressed, renal dialysis/catheterization

Term
three conditions that lead to HAIs
Definition

presence of microorganisms in hospital environment

immunocompromised pt

transmission of pathogens between staff and pt and among patients

Term
medical asepsis
Definition

clean technique

goal: exclude pathogens

Term
surgical asepsis
Definition

sterile techniques

goal: exclude all microorganisms

practices used to render objects sterile

Term
airborne precaution
Definition

air being removed from room is filtered

room is under negative pressure

air entering from hallway

Term
exceptionally vulnerable
Definition

air entering room is filtered

room is under positive pressure

air from pt room enters hallway

protect pt from everyone else

Supporting users have an ad free experience!