Exam 1 Flashcards
microbiology
study or organisms too small to be seen clearly with the human eye
bacteriology
the study of bacteria and diseases they cause
mycology
the study of fungi and fungal diseases
parasitology
the study of pathogenic protozoa and their diseases
virology
the study of viruses and viral diseases
who is credited with the first accurate description of bacteria
Leeuwenhoek
who is responsible for finally ending the controversy surrounding the theory of spontaneous generation
Pasteur
what commercially important process was Pasteur studying when he developed the technique of pasteurization
fermentation of wine
who was the first person to attempt to control infection during surgery through the use of an antiseptic
Lister
who was the first person to demonstrate the causative role of bacteria in infectious disease
Koch
what group of infectious agents was discovered by examining bacterial-free filtrates
viruses
what investigator first discovered the concept of immunization
Jenner
what is bacteremia
the presence of bacteria in the blood
what is sepsis
bacteria multiplying and forming toxins in the blood (serious life threatening)
what is the term used to describe the ability of an organism to produce disease
virulence
what is a carrier
harbors a pathogenic organism but has no symptoms of disease, but could pass it on
what is an obligate pathogen
organism that always causes disease
what is an opportunistic pathogen
causes disease only under certain conditions
what is antiseptic
removes or inhibits growth of microorganisms on living tissue
what is disinfectant
removes or inhibits growth of microorganisms on inanimate objects
bacteria shapes
cocci, bacilli, spirals
amphitrichous flagella
one flagella at both ends
atrichous
no flagella
lophotrichous flagella
more than one flagella at one end
monotrichous flagella
one flagella at one end
peritrichous flagella
flagella all over the cell
characteristics of bacterial spores
only in Gram +, do not stain with Gram stain, dormant state that is resistant to drying, heat, chemical disinfectants and radiation
prokaryotic organisms
nuclear structures are without limiting membranes
prokaryotic organisms examples
bacteria and blue-green algae
eukaryotic organisms
possess true nuclei
eukaryotic organisms examples
fungi, algae, protozoa, plants and animals
what is the most specific basis for the taxonomy and classification of bacteria
nucleic acid hemology
phototrophs
obtain energy from the sun
what is the term used to describe organisms that use only molecular oxygen as the final hydrogen acceptor in respiration
obligate aerobes
what is the final hydrogen acceptor in fermentation
an organic compound
what is meant by facultative
organism can grow with or without oxygen
how would you classify an organism that grows best a body temperature
mesophilic
what is the most convenient method for obtaining a pure culture from a mixed culture
streak plate
what is mordant
gives dye an attachment point, increases the affinity of the dye
what stains are used to demonstrate the presence of acid-fast bacteria
Zeihl-Neilsen, Kinyoun method, and fluorochrome method
melting point of agar
97 C (100)
gelling point of agar
45 C
how would you characterize sheep’s blood agar
Enriched differential media (differentiates hemolysis)
several aspects of a quality control program in the microbiology laboratory
reagents, temperature, personnel, media
what is the most generally used means of sterilization for the hospital laboratory
autoclave
how would you sterilize media that cannot withstand high temperatures
filtration
how was penicillin “accidentally” discovered?
Fleming was trying to grow bacteria, but it got contaminated and the bacteria would not grow near the mold (penicillin)
how would omitting mordant affect the Gram stain?
the dye would get washed out during decolorization and be pink
what portion of the bacterial cell has the most to do with whether it stains Gram pos or neg
cell wall
what chemical constituent of this structure is responsible
lipids and peptidoglycan
list several conditions necessary for the optimum cultivation of bacteria
proper incubation temperature, moisture, pH, atmosphere
describe the various modes of action of disinfectants
react with cytoplasmic membrane, denatures cellular proteins and enzymes, damages DNA and/or RNA
what antiseptic is used to prepare the skin for venipuncture
isopropyl alcohol
what is the best overall disinfectant for hospital use
10% Clorox
list several characteristics of an acceptable clinical specimen for microbiology
sterile container, labeled properly, time of collection and received
how soon should all specimens be cultured
as soon as possible
normally sterile areas of the body
CSF, blood, joints, body cavities, gall bladder, stomach, duodenum, renal tract, middle ear
normally inhabited areas of the body
skin, auditory canal, eye, mouth, throat, sputum from respiratory tract, large bowel, vagina
when you read cultures from areas that have normal flora, what is the main consideration
recognizing what should not be there
Micrococcus appearance
very large and yellow
Gaffkya appearance
occur in tetrads
Sarcina appearance
bright yellow pigment in groups of eight
what test is used to distinguish Strep and Staph
catalase
catalase test for strep
catalase negative
catalase test for staph
catalase positive
What is the tube coagulase test?
take organism put it in tube of diluted plasma and incubate
What type of coagulase does tube coagulase test for?
free coagulase
What is hyaluronidase?
known as the “spreading factor,” dissolves the substance between the cells allowing the organism to penetrate the tissues
name characteristics of the enterotoxin produced by S. aureus
enterotoxin is an exotoxin that acts on intestines, it is not destroyed by boiling, causes food poisoning
what technique is used to track down the specific strain of S. aureus responsible for outbreaks of infection in the nursery or O.R.?
phage typing
Name some of the diseases caused by Staph
pimples, boils, acne, cystitis, gastroenteritis, sepsis, meningitis, acute bacterial endocarditis, pneumonia, scalded skin syndrome, TSS, impetigo
What biochemical characteristics distinguish aureus from epidermidis
coagulase, salt tolerance, DNase; aureus is positive for all, epidermidis is negative
how is saprophytic differentiated from other Staph?
saprophyticus is resistant to novamycin, S. epi is not resistant
colony of Staph aureus that is trapped in agar pour plate is small and hemolytic resembles what Strep
Beta Strep
what is the purpose of stabbing the agar when doing a throat culture?
enhance hemolysis due to Streptolysin O
which hemolysin is enhanced by stabbing the agar?
Streptolysin O that stands for oxygen labile
which of Lancefield’s groups of Strep are responsible for most clinical infections?
Group A Beta Strep
what Lancefield group is Streptococcus pyogenes?
Group A
which group does Streptococcus agalactiae belong?
Group B
which group of Streptococcus is associated with UTI’s and wound infections, but are normal flora of the GI tract?
Group D Strep
what is the role of the capsule in infections due to Strep. pneumoniae?
primary virulence factor
what is the most common cause of subacute bacterial endocarditis (SBE)?
Alpha Strep viridans
what organism would be indicated by a Gram stain of foul smelling pus from a brain abscess that shows Gram positive cocci in chains?
anaerobic Strep
which strain of Streptococcus is associated with infections due to Mycoplasma pneumoniae?
Streptococcus MG
What is the reagent used for the oxidase test used in the identification of Neisseria?
tetramethyl-p-phenylenediamene dihydrochloride
What antibiotics are found in MTM
vancomycin, colistin, nystatin
what does vancomycin do
inhibit Gram pos
what does colistin do
inhibit Gram neg rods
what does nystatin do
inhibits yeast and molds
what infections are caused by Neisseria gonorrhoeae?
Gonorrhea, opthalmia neonatorum, arthritis
what specimen is used to detect carriers of Neisseria meningitidis?
throat culture
What enzyme is produced by strains of Neisseria that are resistant to penicillin?
Beta-lactamase
