[Histonet] AFB organisms in tap water

Bryan Llewellyn bryand <@t> netbistro.com
Wed Dec 10 12:09:41 CST 2003

Mycobacteria lurking in taps is not an urban legend, it is real.  I have had
it happen.  We traced some ZN positive bacteria to the crud (a technical
term) on the inside of a vacuum trap at our special stains bench.  The
minerals in the water and, I presume, the materials in the air were enough
to grow plates of the organisms. Fragments of these plates broke off and
adhered to sections giving false positives.  The organisms were thicker and
longer than TB and strongly beaded, but who knows what others could look
like.  After that I regularly cleaned the inside of all the taps in the lab
with brushes, and it never happened again.

Bryan Llewellyn

----- Original Message -----
From: "louise renton" <louise_renton <@t> hotmail.com>
To: <histonet <@t> lists.utsouthwestern.edu>
Sent: Wednesday, December 10, 2003 12:08 AM
Subject: RE: [Histonet] AFB Positive Patient

> Kevin,
> Hi Kevin,
> I have seen a slide of lymph node  from a patient with a severely
> immunocompromised state who has such a superabundance of AFB that the
> section was visibly pink to the naked eye. Needless to say, these sections
> were NOT used as controls for routine work. Interestingly, when PCR typing
> was performed, the bugs turned out to M avis and not MTb as initially
> suspected.
> This is completely  anecdotal, but I have heard of various mycobacteriae
> lurking in tap water, that show up on sections washed in that water,
> "false positives". Has anyone else anything to offer on this possible
> legend?
> best regards
> Louise Renton
> Bone Research Unit
> Johannesburg
> South Africa
> Tel & fax +27 11 717 2298
> "Time flies like an arrow, fruit flies like a banana"
> ----Original Message Follows----
> From: "kevin williams" <akwilliams75 <@t> hotmail.com>
> To: histonet <@t> pathology.swmed.edu
> Subject: [Histonet] AFB Positive Patient
> Date: Tue, 09 Dec 2003 19:50:24 +0000
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