susceptibility of ultra-bacteria to heat?

Joan Marie Shields jshields at rigel.oac.uci.edu
Tue Jul 13 11:33:13 EST 1999

Someone wrote:
> Water treatment plants
>>usually screen for Cryptosporidia but sometimes they slip through the
>>net obviously.

Bottomley <4hotbear at uffdaonline.net> wrote:  
>Most water treatment plants don't test for Cryptosporidia.  The test is very
>expensive and they only test if there is cause too believe the test is
>necessary.  My husband runs the water treatment plant here and says the
>tests are upwards of $10,000.  The routinley test tor e.coli.

Are you sure about this?  I know that they are expensive but I can't see
that a test for Cryptosporidium costs anywhere near $10,000 - although, 
this may well be the cost of tests over a year (charged by a processing
lab).  I'm working on a methodology for testing for Cyclospora in water (it's
another sporulating parasitic protozoa).  I've been looking at means other
than cartridge filtration (the high tech ones run about $100) and 
microscopy (I've been working with surface water which tends to be a whole
lot 'dirtier' than finished water- try sifting through 200uL of packed
pellet 10uL at a time with wet mount slides - ugh).  

As far as I know, many water treatment plants do test for Cryptosporidium
on a semi-regular basis.  I do know that quite a few are evaluating
methods.  It may well depend upon the source water a treatment plant uses -
although last year's outbreak of cryptosporidiosis in Texas showed that
under certain conditions Crypto. can perk through the ground pretty 
successfully.  It may also depend upon the area of the country.  I do know
that not all plants do this but I do know that some do.  It's probably only
a matter of time before all plants (or any plants that use surface water)
are required to.

Chances are it's probably a whole lot more common than we think it is -
mostly because themethods we have to test for it are not all that
reliable - recovery rates being about 5-30% in general (though there are
tests that claim a higher recovery rate - depends on the quality of the
water, inhibitors, skill of the person doing the test, etc).

Joan Shields       jshields at uci.edu       http://www.ags.uci.edu/~jshields
University of California - Irvine         School of Social Ecology
Department of Environmental Analysis and Design
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