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Elaine's point is one you missed completely. She knows that E. coli can grow
under aerobic conditions, but only when suitable competition and predation
Using www.google.com I did a bit of searching for 'E.coli survival soil' and
found some interesting morsels:
" In general, sterile distilled water promoted the survival of the organism.
At 15°C in the laboratory, for example, a 1.5 log10 cfu/ml reduction was
observed after 31 days when the initial inoculum level was 3 log10 cfu/ml.
This contrasts with the disappearance of the organism in farm water after 10
days under the same conditions."
"Wang and Doyle (1998), in studies on the survival of a mixture of five
E.coli O157 strains in municipal, reservoir and lake water, recorded
survival times of approximately 50 to 80 days. Rice et al. (1992) made
similar findings. These contrast with the results reported in this paper,
which suggest the organism declines more rapidly and may be undetectable in
as short a period of time as 7 days. Such inconsistencies in survival data
for E.coli O157 may be due to differing microflora in the water samples. "
Hold onto that thought, Klaus, and consider Elaine's full contention:
[aerobic growth of E.coli] " It does happen, but ONLY IF competing aerobic
organisms are not present."
"Here's another example - We take cultures of E. coli and dump them in soil.
If the soil has a healthy foodweb, you will not detect E. coli in 24 hours.
Ah, but if the soil is not healthy, and lacks good structure, you can detect
E. coli for many days. "
So, the range for E.coli survival in soils is contingent on the presence or
absence of a healthy foodweb, per Dr Ingham.
It has long been known that unfinished compost can be reinoculated with
pathogens and fecal coliforms and generate regrowth of those organisms.
Finished compost will not support regrowth. The reason for that is that a
competitive microflora is established in finished compost during the
mesophilic ('curing') phase that controls pathogenic organisms.
It has also been known, but only recently demonstrated repeatedly in the
lab, that vermicomposting brings about rapid destruction of bacterial
pathogens and indicators. This happens around room temperature, unlike
thermophilic composting, and involves the remediation of pathogens and
installation of a competitive microflora happening simultaneously. The exact
mechanisms through which Salmonella, E.coli and other such organisms are
destroyed are not thoroughly understood, but the fact that they are
destroyed is well established. Vermicompost will not support pathogen
It thus follows that while a 'compost tea' made from underprocessed manure
containing a substantial population of E.coli might indeed lack the
competitive microflora to inhibit pathogen regrowth, which is one
explanation of the Bess study,
a 'compost tea' made from good vermicompost or compost which has a low E.
coli count to start with, plus the inhibitory microbial consortia present,
can logically be expected to behave as Dr Ingham asserts.
Dr Ingham herself suggests that Bess's study reported faulty DO levels, and
that the system must have dipped into the anaerobic zone for the kind of E.
coli growth she obtained to occur. An alternative explanation is one of
microbial absence, the lack of the competitive organisms needed to control
Bess's study does underscore the need for high quality compost in the making
of compost tea for fresh fruit and produce. She demonstrated at least that a
poor compost in a system that looked, and even measured, as aerobic, was
able to generate E.coli growth when fed certain nutrients.
However, this does not refute Dr Ingham's claim that a good quality compost,
with no or low E.coli counts to start with, would not support E.coli growth
in a properly managed compost tea environment.
Her point, if I understood her well, is that in an anaerobic situation E.
coli growth was quite possible due to the inhibition of the normally
controlling aerobes, but that in an aerobic environment with a full foodweb
present, E. coli will not only not increase, but be substantially reduced.
If you can pull yourself out of your cognitive dissonance and deal with the
assertion that is actually being put forward, perhaps we can get somewhere
with this discussion.
----- Original Message -----
From: "Klaus Wiegand" <wiegand@LUFA-SPEYER.DE>
Sent: Monday, November 04, 2002 7:45 AM
Subject: Re: [SANET-MG] E.coli
> On 4 Nov 02, at 5:22, Elaine Ingham wrote:
> >Ok, let's go over this again.
> >PLEASE, understand that microbiologists are missing the point
> >when they say that E. coli can grow aerobically.
> please understand, that soil scientists are missing the point, when
> they say the E. coli cannot grow aerobically.
> a) ever heard of escherichia switching to mixed-acid-production
> (lactic/butryl/acetic and some others) under aerobic conditions ?
> b) ever seen them them grow in tatar (minced meat) in a kitchen,
> where mother will not die from asphyxation ?
> c) ever wondered, why they grow perfectly well on almost any
> growth medium like conkey, mda or pda in petri-dishes with these
> nice special knobs on the bottom (for air supply) ?
> d) one of the major site of nosocomial infection (30% of all
> infections) are pneumonias. hardly the proclaimed anaerobic
> conditions you assume.
> general rule of thumb is, that e. coli will survive up to 9 months in
> soil contaminated with them by sewage or sewage sludge (agricola
> or ovid life science should give appropriate results)
> >So, in the lab, the right temperature, rich medium, often
> >antibiotics, and NO SIGNIFICANT NUMBERS OF COMPETING
> >BACTERIA are all required to grow E. coli in
> >fully aerobic conditions.
> uhhuhh, we find them quite often in cheap foodstuff (when MBM
> was still allowed, we found them regularely in 70% of mixtures
> containing MBM) with the usual aerobic colony counts of 10 ^8 to
> 10 ^9 / gr - incubation in usual temperature chambers (overgrown in
> foodstuff with colony numbers above). simple pretesting by vicam,
> our experienced technicians have a success rate of about 90%
> counterchecked by serology.
> >If you want, you can ask whoever is saying E. coli grows
> >aerobically where their scientific data are, and I'll be happy to point
out where they are
> >missing the point.
> done by this mail. questions see above under a) to d)
- Re: E.coli
- From: Klaus Wiegand <wiegand@LUFA-SPEYER.DE>