Molecular Microbiology Question

Azam Kanani akanani at
Thu Mar 16 23:10:16 EST 1995

Hi there.  I have a question in one one of my microbiology courses due 
Tuesday and I haven't a clue how to do it.  Please mail me directly if 
you have any ideas.  Any help would be appreciated and thanks in advance.

You are asked to consult for a pharmaceutical company and they want your 
analysis of the pattern gene expression they have noticed in a strain of 
Enterococcus faecalis which is resistant to MLS antibiotics other than 
erythromycin.  They give you the following information:

1)  The S.aureus strain can induce resistance in under 30 minutes as 
measured by an increase in optical density after lag phase if small 
amounts of MLS antibiotics are added to the medium.

2)  The addition of rifampicin does not affect this induction period; the 
addition of streptomycin does affect the resistance of MLS antibiotics.

3)  The induction of drug resistance was sensitive to rifampicin if the 
culture was grown in Todd Hewitt broth containing extra glucose.

4)  Phosphorylation studies on cytoplasmic membrane proteins revealed 
one protein which was labelled with 32P (radioactive) in the presence of 
MLS antibiotics.

The company president has been reading Popular Scientist and thinks the 
control mechanism involves an antisense RNA.  Do you agree with him?  
Describe your model.  Describe one experiment to test your hypothesis.

Again thanks for any help.

Azam Kanani
akanani at

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