Subject: Re: Identification of a nasty fungus

From: [email-masked] (Dan Ebbole)
Date: 28 Jan 1996 11:19:20 -0800

Peter Harris libelously wrote:

>I don't know what your present general line of research is but you have 
>just equipped yourself with the favourite fungus of the fungal 
>geneticists - Neurospora (probably Neurospora crassa after its crass 
>habits ?). Spores like mad and will get everywhere. You may even find 
>that you become "persona non grata" in other peoples labs, cos they 
>don't want it either. Many years ago, here at Reading University UK, we 
>suddenly had a lot of Neurospora around just by having a visiting 
>speaker who specialised in it !
>If I see a plate with a suspected Neurospora on it, it gets its own 
>private immediate trip to the autoclave, Not very PC I agree, but thank 
>God we can still be prejudiced against SOMETHING.

1.  The "nasty" fungus may indeed be somehow related to Neurospora, it is
certainly not N. crassa.  

2.  Contamination problems can occur with virtually any conidial fungus
>from  time to time.  But the above story is certainly a gross exaggeration
if not an outright fabrication.  We have a number of fungal labs in the
building my Neurospora lab is in.  No other lab has EVER reported
Neurospora contamination.  On the other hand, my lab and almost every other
lab has often seen contamination from Aspergillus (probably from the
environment, not the Aspergillus lab on the floor?).  

The idea that Neurospora is a major contamination problem is a myth as far
as I can tell.  With the same care in handling, Neurospora is no more of a
contamination problem than the Aspergilli.  In fact, I am sure that it is
less of a problem for neighboring labs then Aspergillus, since the smaller
Aspergillus spores travel much farther before settling.  I do not wish to
suggest that we  autoclave all the Aspergillus cultures.  I also work with
Aspergillus (a little) as well as Neurospora. (Although the work with
Aspergillus is done in another lab to keep our Neurospora strains from
getting contaminated).

P.S.  Peter, perhaps we'll chat about this over a beer someday!

------------------------
Dr. Daniel Ebbole
[email-masked]
Assistant Professor
Dept. of Plant Pathology and Microbiology
Texas A&M University
College Station, TX 77843-2132
USA

---

From: David Geiser <[email-masked]>
Date: 29 Jan 1996 06:07:26 GMT

In article <[email-masked]> Dan Ebbole,
[email-masked] writes:

>Neurospora contamination.

My guess is that labs may be the source of a contamination, but they are
really not the problem.  I'll bet the problem is usually a bad
ventilation system,  or a constant temperature room that's too humid, or
lots of old cultures,  plant material or food left lying around. 
Everyone will
occasionally get an odd colony growing on a plate,  but I think real
problems are caused by the facilities.

  On the other hand, my lab and almost every other
>environment, not the Aspergillus lab on the floor?).  

Most likely the environment.  I worked with wild-type strains of 
various Aspergillus spp. in an Aspergillus genetics lab,  which was
a great source of paranoia.  I shared the incubator with everyone else
in the lab,  most of whom worked with strains that required nutritional
supplement,  and most people did their sterile work right on the
benchtop.  I only know of one instance where one of my strains
was certainly growing on someone else's plates.  I occasionally found 
an obvious lab strain growing on one of my plates,  but this was very 
rare. We were in a new building with excellent ventilation,  and I'm sure 
that helped.   The "Aspergillus" contaminants I've seen have almost always
been A. fumigatus,  A. niger,  or Penicillium,  so one should not
blame the A. nidulans lab down the hall because of an Aspergillus
contaminant.

>contamination problem than the Aspergilli.

I think this is true.  Working on Aspergillus next door to a Neurospora
lab,  I don't remember ever seeing or hearing about Neurospora as a
contaminant.  I'm sure that any Neurospora scientist worth his or her
salt would not grow conidiating strains on petri dishes and let them
get out of hand. The contaminant reported  that started this thread was 
>from   New Orleans,  LA,   and Neurospora is commonly isolated from sugar 
cane  fields in Southern Louisiana.  Maybe Neurospora (more likely its
anamorph) is more of a contamination problem in Louisiana than elsewhere.

Dave Geiser