Question | Answer |
1) Define microbiology | a) The study of microorganisms |
a) Nutritive | growth of wide range of microorg. (most non fastidous) without giving any particular org a growth advantage
*Sheep Blood |
b) Differential | contains some factors that allow colonies of one bacteria to show some metabolic/culture characteristics that can be used to distinguish them from other bacteria on the same plate
*blood,emb, mac |
selective | growth of one group of microorg, but not another
cna,mac,
*Mac, cna |
Supplemental/enrichment | lim, chocolatte |
When can a specimen be rejected | label and requisition dont match, improper transport medium, qns, leaking, transport time longer than 2hrs, dry. |
Define genus | genus: diff species that have similar morphology, physiology and genetic traits but maintain individual status |
strain | subset of bacterial special that differ by minor differences |
species | collection of bacterial strains that share many common physiologic and genetic features |
explain nomenclature | binomial system
genus(capitalized)
species (lowercase)
*Staph. aureus |
Sterilization:
physical method
chemical method | all microbial life are killed
physical:incineration, moist/dry heat, filtration, ionizing radiation.
chemical: ethylene oxide, formaldehyde, glutaraldehyde, peracetic acid. |
Disenfection:
physical method
chemical method | most orgs, not all are destroyed
boiling, pasteurizing, uv light
alcohols, aldehydes, halogens, heavy metals, amonium, phenolics |
Material safety data sheets | info about the chemical |
TYPES OF FIRE EXTiNGUISHERS
A | A-green triangle(trash, wood, paper)
-employs water/all purpose dry chemical |
B fire extenguisher | red square (chemical fire)
employs foam, dry chemical or co2 |
C fire extenguisher | blue circle (electrical fire)
employs nonconducting extinguishing agents co2 or dry chemical. |
RACE acronym | Rescue injured
Alarm
Contain fire
Extinguish fire |
discuss electrical safety | check cords for fraying, all cords must be 3 pronged grounded, no extension cords |
Biocide: | (chemical sterilant)-chemical agent that destroys all life |
antiseptic: | inhibiting the growth of microorganisms w/o killing them |
List components of the exposure control plan | Provisions
disposal
engineering controls |
3 mechanisms of genetic change | mutation, recombination, gene exchange |
Mutation: | change in original sequence of a gene |
Recombination | donor DNA--> recipient DNA
exchange of dna occurs |
gene exchange | transformation, transduction, conjugation. |
Binary fission | bacterial replication by cell division
results in 2 daughter cells (asexual process)
Identical DNA |
Gram + cell wall composition | thick peptido glycan layer, lipoteichoic acid and teichoic acid... some have mycolic acid to fortify the murein layer |
Gram - cell wall composition | thin peptidoglycal layer, outer layer has lipids, proteins and polysachharides |
acid-fast | thick peptidoglycan and mycolic acid |
Outer Membrane | protects cell from external environment |
cell wall | gives shape and strength to withstand changes in osmotic pressure. prevents cell lysis,protects from mechanical disruption |
periplasm | only in gram -, helps in detoxification, absorption of nutrients, enzymatic degradation of macromolecules |
cytoplasmic membrane | regulate transport across the membrane and osmotic barrier, location of electron transport |
capsule | protect cell from desiccation and toxic materials promotes conc. of nutrients at cell surface. antigenic, illicit immune response |
pilli | used for attachment, bacterial conjugation, transfer of genetic material in gram - cells. |
flagella | movement |
endospores | protect from environment, guarantees survival |
endotoxins | gram - bacteria produce this
composed of lps
heat stable
low toxicity |
exotoxins | gram +
composed of protein
heat labile |
signs of disease | aches, headache, swollen lymph nodes, rashes, redness, cough/sneeze, congestion, nausea/vomitting, diarrhea |
prevention of disease | immunization and epidemiology |
reservoirs | human, animal, food, environmental |
vectors | mode of transmission (direct/indirect) |
transient flora | don't multiply, shed with host cells |
resident flora | multiply permanent on the host |
pathogen | microorg. that cause infection or disease |
opportunistic pathogen | organism that only cause infection when one or more of the host's defense mechanisms are disrupted |
virulence | degree of pathology caused by the organism. correlated with ability to multiply in the host |
heat fix/methanol fix | preserve and fix in position the internal/external structure of organism |
crystal violet | primary stain binds to bacterial cell walls with - charge |
grams iodine | increases the interaction between cells and dye so that its more strongly stained |
decolorizer | acetone/alcohol. damages bacterial with thin cell wall |
safranin | counter stain. stains all unstained elements |
cultivation | growing of living materials |
in vivo | living body of plant/animal |
in vitro | outside living body/in artificial environment |
fastidious | have complex nutritional requirements |
non fastidious | have simple nutritional needs |
environmental requirements for the cultivation of bacteria | o2 and co2 availability |
microaerophillic | need low levels of o2 |
capnophillic | grow well with higher co2 |
faculative anaerobic | grow with or without o2 |
how to evaluate bacterial colony morphologies | types of media supporting growth, quantities of each colony type, size, color, shape, surface, odor, gram stain |
genotypic criteria | identification based on some portion of the genome using molecular techniques for DNA or RNA analysis |
phenotypic criteria | identification based on observable physical or metabolic characteristics of bacteria. Analysis of gene products, not the genes themselves. |
phenotypic criteria used for bacterial identification | macroscopic colony morphology (size, shape, color etc)
microscopic morphology (gram stain, wet prep)
environmental requirements for growth, atmospheric requirements, nutritional requirements, resistance to microbial agents. |
quality control | control of labs analytical error by monitoring analytical performance with known controls and maintaining errors within established limits around the mean control values |
quality assurance | institutional program designed to assess the success of the total organization achieving its goals |
total quality management | improve patient care by monitoring laboratory work to detect and correct deficiencies |
continuous quality improvement/performance improvement | improve patient care by not making a mistakes |
2) Describe the basic elements of a quality control program | a) Specimen collection and transport
b) Sop’s
c) Personnel
d) Referenc labs
e) Patient reports
f) Proficiency testing
g) Performance checks
h) Maintain qc records
i) Maintain qc stocks |
electron microscopy | condenser doesn't allow light to hit specimen. Spirochete detection |
Fluorescent Microscopy | absorb and emit different wavelength of light.
color against dark background |
phase contrast microscopy | light beams pass through specimen and are partially deflected due to density differences. No stains needed |
brightfield | light passes directly through specimen and then through lenses that reflect light |
specimen collection | no transient flora, collected during acute phase of illness, and not prior to ab therapy. |
specimen transport | within 30min of collection, in biohazard bag, at right temp. |
direct microscopic evaluation | gram stain, quality of sputum specimens, presences of WBCS |