Chapter 11 Gnotobiotics Flashcards
Animals that have a normal intestinal flora but are free of particular organisms are called:
Specific pathogen-free
Gnotobiotes, by definition, are germ-free animals.
False
The first functional germ-free animal models were developed by scientists and technicians of the laboratories of bacteriology at the University of Notre Dame.
True
Axenic animals are gnotobiotes.
True
The development of the Trexier flexible film isolators marked the beginning of modern gnotobiotic research.
True
What is the process by which isolators confine potentially harmful microorganisms within the system?
Containment
A rack environment with a large volume of flowing, filtered, sterile air is called a:
laminar flow rack
What function does a transfer sleeve serve?
To connect the supply cylinder to the isolator entry port.
Isolators must operate with positive pressure with respect to the room.
False: either positive or negative.
Why have laminar flow cabinets recently become more frequently used that isolators for maintaining gnotobiotic animals?
Increased accessibility of animals.
Supplies must be sterilized before being passed through the supply cylinder.
False: they are sterilized inside the supply cylinder
Before housing gnotobiotic animals, isolators should be tested multiple times for 3-6 weeks to ensure the abscence of contamination of bedding, shelves, feed and water.
True
What is the term for the killing of all living organisms?
Sterilization
Hysterectomy derivations are done using nonaxenic mothers and axenic foster mothers.
True
What amino acids are required in lesser quantities in axenc animals?
Lysine and cyseteine
Why are foundation colonies generally maintained in the defined flora state instead of in the axenic state?
To optimize litter size
Gnotobiotic animals require fortified feed to replace the vitamins broken down by autoclaving.
True
The process by which the embryos from a superovulated mother are removed, washed, and transferred to the reproductive tract of a pseudopregnant axenic female in a surgical isolator is called hysterectomy derivation.
False
The tissue enzyme level of axenics tends to be higher than those of normal animals.
False
Axenic rats have smaller hearts, livers, and lungs compared to non-axenic rats.
True
What is a good choice to help maintain genetic integrity when producing axenic pups by hysterectomy derivation?
Make sure that the donor female and the foster mother have a different coat color.
Pups that have been hysterectomy derived can be assumed to be germ-free and transferred to a barrier facility.
False
What is a “Schaedler cocktail” or “altered Schaedler cocktail”?
A solution containing a variety of normal flora bacteria.
Which vitamins are required in lesser quantities in axenic animals?
Vitamin A and Vitamin E
Which vitamins are required in lesser quantities in axenic animals?
Vitamins A and vitamin E
What is NOT an appropriate sterilization method for gnotobiotic systems?
Carbon dioxide
What is the term for the stainless steel container in which materials and supplies are sterilized before placing in the isolator?
Supply cylinder
Which of the following represents a difference between hysterectomy derivation and embryo transfer?
In hysterectomy derivation, the fetuses are at term, but in the other technique, embryos used are at an earlier stage of development.
