Bacterial identification through functional media - motility testing Flashcards
T/F : Functional media are used to identify unknown microbes.
T
T/F: Motility tests are conducted with soft gel media.
T
T/F: Clear media is a positive test result for motility.
F, turbid is positive
T/F: all motile bacteria have one or more flagella.
False
Gel that prevents the diffusion of some microbes.
Motility media
Bacteria with a single flagellum at each end.
Amphitrichous
Bacteria with numerous flagella at one end.
Lophotrichous
Agents that prohibit the growth of some microbes
Selective media
What are the three primary types of functional media?
Selective, differential, enriched
What is selective media?
Selective media contain agent(s) that prohibit the growth of some organisms, thus selecting or allowing the growth of other organisms. This is especially helpful when growing mixed cultures containing many different microbes when only one or two specific microbes are of interest.
What is differential media?
Differential media enable many types of microbes to grow; however, differential media contain an indicator that enables differences between microbes to be visualized.
What are enriched media?
Enriched media are supplemented with essential growth factors for organisms that do not grow well on typical media.
_____ is a form of functional media used to identify unknown microbes.
a.) Selective
b.) differential
c.) enriched
d.) all above
d
_____ media contain an indicator that enables differences between microbes to be visualized.
Differential
How do bacteria move?
acteria move by a variety of mechanisms including flagella, axial filaments, and slime secretions
_____ bacteria have flagella distributed all over the surface of the cell.
Amphitrichous
Monotrichous
Peritrichous
All of the above
Peritrichous
T/F : Growth only along the stab line is a negative test for motility.
T
Motility media is a _____ used to detect bacterial movement.
soft gel
_____ is a positive test result when using motility media.
Turbidity
How does the agar media used for motility testing differ from that used for your plate cultures?
Functional motility media is used for conducting motility tests. The functional motility media is a soft gel consisting of 0.4% agar. The gel consistency allows motile bacteria to move throughout the media while preventing diffusion of non-motile species. The functional motility media differs from that of the plate agar because the plate agar uses a solid media agar and is primarily used for culturing microbes and typically consists of 1.5 - 2.0% agar.
What can you conclude regarding the motility of E. coli and S. epidermidis based on your results?
Since the E. coli did not present a clear stab line, and maintained a turbid color throughout the tube, the E. coli was positive for the motility test. In other words, the E. coli experienced growth throughout the tube, thereby indicative of motility. The S. epidermidis has a negative result because it had a clear stab line and the tube had a turbulent appearance only at the stab line, thereby indicating microbial growth only at the stab line and a lack of motility.
_____ media contain agent(s) that prohibit the growth of some microbes.
Selective
t/f Motility media is an example of differential media because it enables differences between microbes to be visualized.
T
T/F Motility is an important characteristic for classifying microbes.
T
