Name a pathogen that produces H2S but does not ferment lactose or sucrose.
E. Proteus vulgaris
F. proteus mirabilis
G. salmonella typhimurium
Name a pathogen that may inhabit the stomach and produces the urease enzyme (we can detect it
using that method; refer to chapter 21 and discuss with your table)?
Name a possible pathogen that is motile and produces indole.
A. Escherichia coli
D. Serratia marcescens
E. proteus vulgaris
Name a pathogen that is non-motile but ferments glucose.
B. Klebsiella pneumoneiae
H. Shigella flexneri
Use the color and the results of indole and try to identify your unknown. How did the
identification of your bacterial unknown on the Chromagar/Indole compare to the tube
biochemicals identification? Was it 100% successful?
No, but close
What is the cellular target of the acid fast stain?
mycolic acid in the cell wall
What genera of bacteria is typically acid fast?
Mycobacterium and some Nocardia
Discuss two diseases caused by acid fast bacteria.
Mycobacterium tuberculosis causes Tuberculosis.
Myobacterium leprae causes Leprosy
Explain how the acid fast property of the bacterium is a virulence factor?
The myolic acid of myobacterium clump the cells together. it is a virulence factor that allow them to survive in phagocytes and make them resistant to disinfectants & antimicrobial therapy.
If a patient has acid fast bacteria in the sputum specimen they provided, does this mean they have
tuberculosis? Why or why not?
Yes, if it is Myobacterium tuberculosis that is an acid fast bacteria that cause tuberculosis.
Explain a screening test and a more definitive test for diagnosis of tuberculosis.
There are number of tests for tuberculosis.
skin testing (screens people with high risk for tuberculosis but may have false results even if it test positive)
Direct identification of myobacterium tuberculosis in sputum.
Cultural isolation & identification
Do animals get tuberculosis?
Explain the meaning of tuberculosis as a re-emerging infection.
After tuberculosis had been controlled and the number of infections was reduced around the world, myobacterium tuberculosis developed multi-drug resistance and now the number of infections is on the rise.