Re: Leprosy and spirochete tissue controls

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From:Don Hammer <>
To:Lee & Peggy Wenk <>
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You are so smart and knowledgeable!  So many run controls on various stains
that are over populated and lose the intent to demonstrate.  :(

Don Hammer, Retired Guy (heading to Las Vegas and Palm Springs for a week in
money and Sun!!!!)  *big, big, big, grin* and a  non-melanoma tan too!

----- Original Message -----
From: Lee & Peggy Wenk <>
To: <>
Cc: <>
Sent: Sunday, March 12, 2000 5:19 AM
Subject: Re: Leprosy and spirochete tissue controls

> I  hope it wasn't something I said that makes you feel "very ancient."
> ;-)
> Anyway, an additional comment on the Leptospira from dog liver. This is
> a
> very large spirochete, probably one of the largest. If you use this for
> your control, and your patient's tissue has syphilis, one of the
> smallest
> spirochetes, you may end up with a false negative on your patient's
> tissue.
> The larger Leptospira gets developed first, due to its larger size. The
> smaller Treponema (syphilis) needs a longer time in developer, before
> it becomes visible. It may take as much as 30 minutes longer in
> developer
> from the time you first see the Leptospira until the Treponema are
> visible. Think of it like an airplane in the air. What can you see
> easiest - the Great Wall of China, or the people on the wall?
> The same thing can happen if you are using fungus as your control
> when you are looking for the much smaller Pneumocystis. Possible
> false negative for the patient's P.C.
> Moral of the story is . . . always use control micro-organisms that
> are comparable in size when doing silver stains.
> P.S. I'll be at the Florida Regional meeting this week, and will
> be giving a 3 hour workshop on controls on Friday, if you want to hear
> more "exciting" tidbits like this. Hope to meet some Histonetters there!
> Peggy A. Wenk, HTL(ASCP)
> William Beaumont Hospital
> Royal Oak, MI 48073
> wrote:
> >
> > Peggy Wenk replies to a question about spirochete and lepra bacilli
> > The old Samurai Pathologist feels very ancient - they don't teach this
> > in residencies much any more.
> >
> > Someone on the list recently suggested a veterinary source for a
> > control - namely Leptospira, and that's what I would go looking for.
Dogs die
> > of leptospirosis fairly often. The organism is somewhat hazardous in the
> > fresh state, not when fixed. Spirochetes in general are not easy to
> > and Treponema pallidum, the etiologic agent of syphilis, has never been
> > cultured successfully.
> >
> > Leprosy requires control tissue containing the etiologic agent of the
> > disease, Mycobacterium leprae, which has also never been cultured. It is
> > acid-fast organism, but it does not have the same staining
characteristics as
> > Mycobacterium tuberculosis, and there is no substitute for it as a
> > Leprosy affects armadillos, and one leprous armadillo liver would supply
> > universe of histologists with controls.
> >
> > Tim Morken at CDC, do you have any leads on this stuff?
> >
> > Patient advocates will note that they prefer the term "Hansen's disease"
> > the human disease traditionally called leprosy, but this usage is hard
> > maintain when talking about tissue.
> >
> > Bob Richmond
> > Samurai Pathologist
> > on the road in a motel in Mississippi this morning

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