Flashcards in BB Ch 12; microbiological quality control Deck (48)
have a completely defined microflora
free from infection with a defined list of infectious agents
what are the characteristics used to distinguish pathogenic bacteria and fungi from commensal and autochthonous (indigenous)
their ability to cross anatomic and biochemical barriers to establish themselves in niches devoid of other microorganisms
ls it some common bacterial pathogens found in rodent species
Salmonella, mycoplasma pulmonis, helicobacter hepaticus, clostridium piliforme
list some opportunistic bacterial pathogens found in rodent species
Pseudomonas aeruginosa, B hemolytic streptococci, Staphylococcus aureus, and Pneumocystis
what does SOPF stand for? why is it significant?
specific opportunistic pathogen free. free of opportunistic as well as primary pathogens
what is the most effective "gold standard" for rederivation of mice?
embryo transfer, the zona pellucida that surrounds embryos and oocytes excludes pathogens
food is typically heated to what temp during pelleting?
gamma radiation of food is performed using what source?
cobalt 60 source
UV radiation of supplies is done at what wavelength?
210-328 nm, peak DNA absorption is 260nm
limitations of UV radiation
UV light source loses intensity or becomes dirty and by the presence of particles and dissolved organics in water. does not pass through solid objects
limitations of radiosensitivity?
correlates with genome volume and the ability of the organism to repair DNA damage. small viruses such as parvoviruses are highly resistant to UV and gamma irradiation, as are bacterial spores, protozoan cysts, and vegetative bacteria with highly efficient DNA repair.
give some examples of denaturant disinfectants?
quaternary ammonium compounds
give some examples of reactant disinfectants?
give some examples of oxidant disinfectants?
halogens (chlorine bleach, chlorine dioxide)
peroxygens (vapor phase H2O2, virkon S)
mechanism of action for phenolics and quaternary ammonium compounds
disrupt lipid membranes, potent against lipophilic (paramyxo, corona, arena) viruses than hydrophilic
mechanism of action of oxidants?
attack all organic compounds, inactivate hydrophilic (picorna, parvo) as well as lipophilic viruses
what tests are traditionally used to screen rodent biologicals for rodent viruses? and how is this test performed?
mouse or rat antibody production tests
SPF rodents are inoculated with the test article orally and parenterally, held in isolation for a month, and tested by serology for antibodies to rodent viruses.
define direct health monitoring
testing is performed on specimens from the principle/resident colony
define indirect health monitoring
testing is performed on dedicated animals that have been exposed to the principle/resident colony or their bedding or environment
what is considered the gold standard for detecting helminth infections?
low power dissecting microscopy of macerated GI tract, ie direct microscopic examination
what is the sensitivity of gross and microscopic examination of lesions?
low, lesions must be present at high concentrations to be observed
efficacy of transimission of mite infections via soiled bedding?
mites are NOT transmitted well between animals via soiled bedding
MacConkey's agar contains what additive, and this additive has what effect?
crystal violet and bile salts, inhibit growth of gram + bacteria while allowing most gram - bacteria to grow
what enrichment broth is used to recover salmonella from feces or the intestinal tract?
what are the conditions that most cultures are incubated at?
aerobically at 35-37C
what are some fastidious lab animal pathogens for which other identification methods are most ideal?
Mycoplasma pulmonis, Helicobacter, Clostridium pilliforme, CAR bacillus, Pneumocystis.
PCR and/or serology are more often used
what are two ways to identify a bacterial colony from culture?
create a biochemical profile
what does MALDI-TOF MS stand for
matrix assisted laser desorption ionization time of flight mass spectrometry