this strain of E. coli can be associated with TTP but what does the
"H" stand for and is this written correctly --  H:157?

badabing..

Thanks for your question.  Most strains of E. Coli are harmless and
live normally in the intestines of people and animals.  There are,
however, 5 unique classes of E. Coli that are termed as
enterovirulent, or causing inflamation in the stomach and bowels.  The
five classes are:

Enteroinvasive E. coli (EIEC) invades (passes into) the intestinal
wall to produce severe diarrhea.
Enterohemorrhagic E. coli (EHEC) is a cause of  bloody diarrhea. 
Enterotoxigenic E. coli (ETEC) produces a toxin that acts on the
intestinal lining, and is the most common cause of travelers diarrhea.
Enteropathogenic E. coli (EPEC) can causes diarrhea outbreaks in
newborn nurseries.
Enteroaggregative E. coli (EAggEC) can cause acute and chronic (long
lasting) diarrhea in children.

The H in E. Coli H:157 stands for the type of antigen associated with
the bacteria.  There are 3 types of antigens associated with E. Coli. 
The three types are Somatic or O, Capsular or K and Flagellar or H.
From my research, it appears you are referring to E. Coli 0157:H7,
which is associated with Thrombotic thrombocytopenic purpura (TTP),
which typically occurs in elderly patients, as well as
hemolytic-uremic syndrome (HUS) which typcially occurs with children.

Thanks again for your question. I hope the above information has been
helpful.  If you need any additional clarification, please let me know
prior to rating my answer.

Regards,

-THV

Search Strategy:
"E. coli h:157"
"h antigen" Coli
E. Coli H:157
E. Coli strains
Thrombotic thrombocytopenic purpura  E.Coli

References:
E. coli Serotypes
http://web.bham.ac.uk/bcm4ght6/path/sero.html

Intensive therapeutic plasma exchange (TPE) in an elderly cohort of
patients with E. coli O157 related disease
http://web.bham.ac.uk/bcm4ght6/vtec/issue7/vtecv220.html

About E. Coli
http://www.about-ecoli.com/page3.htm

E. Coli 0157:H7
http://www.med.miami.edu/patients/glossary/art.asp?articlekey=2039

---

Request for Answer Clarification by badabing-ga on 09 Apr 2003 18:20 PDT

apologies tar.  granny was in a rush and found most of these things
but she was wondering what the "h" signified.  I found this at the
Dorland's site but I'm on the biology-deficient side.  whattya think?

http://www.mercksource.com/pp/us/cns/cns_health_library_frame.jspzQzpgzEz/pp/us/cns/cns_hl_dorlands.jspzQzpgzEzzSzppdocszSzuszSzcommonzSzdorlandszSzdorlandzSzdmd_h_03zPzhtm


Hauch (Hauch) (houk) [Ger. “breath” (because motile bacteria form a
spreading film around colonies resembling that produced by breathing
on glass)]  used to describe certain bacterial colonies; see H antigen
under antigen and H colony under colony. Symbol H.

---

Clarification of Answer by tar_heel_v-ga on 09 Apr 2003 18:57 PDT

Granny...

Per the norm, you are correct:

"Hauch antigen - now known as H antigen"
http://bmj.com/advice/stylebook/hbook.shtml

Also, for some light reading on the naming conventions of medical
bacteria, you may want to visit
http://www2.ntu.ac.uk/life/sh/modules/hlf249/lectures%5C249-4.htm

Hope this helps!

-THV

tough research to slog through, huh?  looked for that h-word for a
long time today on Google and it was driving me nuts.  thanks for the
assist, extra links, and the light reading.  my eyelids are already
getting heavy .... {yawn}

Thanks for the kind words and the generous tip, Granny!  Glad I could
be of assistance!

-THV