crazy society

[CharlyBonifaz]

I experienced this first hand when I traveled to Europe, where much of the milk is “ultra” pasturized and does not require refrigeration. It was, at least to me, undrinkable.

true 😉
but if you want to drink raw milk there are special farms: monthly healthcheck of cows, more milktesting and higher standarts (f.e. somatic cells less than 200.000); milk must be immediately cooled, handled and stored at temp below +4°C (+39,2F) and used within 96hours after having been milked….

[Tim Harrigan]

So if the range for a healthy cow is 100-1000 per ml, 1000 looks like the upper limit for detectable mastitis. Because milk is cooled to about 40 deg. immediately after milking do you think it is possible for bacteria in milk to increase to 200,000 without outside contamination?

[jac]

My grandmother always said that you couldnt be too clean with the recepticals for milk.. This seems to point to the small producers with healthy cows and spotless practices as opposed to big factories with pipelines a mile long as being the best option… are all those joints in those pipelines not a collecting point for bacteria ??.. it was pointed out earlier that perhaps knowing that pasturisation is the norm that mabey its a case of ” oh well the pasturiser will get it ” and standards slip… Im sure there were farmers in the old days that were less than clean too but we live in a much more enlightened time now and im thinking the big factories are definately not the way to go with a food like milk !!..and even so it still seems mad that tobbaco is so socialy acceptable but folks make a face at the thought of raw milk…
John

[Andy Carson]

If it hard to for me to imagine how 1000 bacteria can go to 100,000 in a bulk tank without outside contamination. Some bacteria can grow at 4 degrees, but they grow really slowly, with doubling times of 1-2 days usually. That means it would take raw milk a week or two to go bad without outside contamination… Unlikely. Another possibility is that the milk is not truely cooled to 4 degrees immediately. Some bacteria can have doubling times of as little as 20 minutes, but still, one hour to cool would turn that 1000 into 4000 and you’d probably still have a week before bacterial counts hit high levels in raw milk. On the other hand, lets say you get a gram of manure on your hands (hard not to), that’s 10,000,000,000 bacteria! Lets say you didn’t wash your hands and contaminated 100 liters of milk. That’s a count of 100,000 right off, and in a day it will be 200,000. Now lets say you washed your hands, and got rid of 99.9% that’s still 10,000,000. Now let’s dilute that ten million bacteria into 100 liters, and you get 100 bacteria (an insignificant addition). The conclusion from all this math is that almost all commercially produced milk must be at least partially contaminated with either sick cows, manure, or incompletely sterilized equipement (if the counts actually approach these upper limits). For these producers, it seems there is little choice but to pasturize. If you wash your hands, take care of your cows, clean your equipment, and drink the milk before it gets old, you ought to have more options.

[Tim Harrigan]

I forgot, what is the infectious dose of O157:H7? I read that there are even more toxigenic strains of E. coli that they will be testing for in the near future. Is that true?

[Andy Carson]

I don’t know the infectious dose off the top of my head. It is a true infection with a hardy oganism, so is probably less than 100 CFU’s, maybe even less in the immunocompromised. Remember we are talking about just o157, not total coliform (which are supposed to be lass than 10) or total bacteria. I am not sure if they will be testing for other serotypes soon, but there definately are other types that cause disease to the same extent as o157… The serotype and the ability to cause disease aren’t really that closely linked at a genetic level, so testing of this and other bacteria is more of a question of “what is mostly likely to cause disease” rather than “what can cause disease”…

[Tim Harrigan]

Countymouse;21044 wrote:

I don’t know the infectious dose off the top of my head. It is a true infection with a hardy oganism, so is probably less than 100 CFU’s, maybe even less in the immunocompromised… The serotype and the ability to cause disease aren’t really that closely linked at a genetic level, so testing of this and other bacteria is more of a question of “what is mostly likely to cause disease” rather than “what can cause disease”…

Yes, probably like water where E. coli is mostly an indicator organism, in most cases not likely to cause a problem but but the presence of it is a red flag that other more pathogenic bugs could also be there. But back to the O157:H7, if it was present even at 1 cfu/ml and the infective dose is 100 cfu, 1 pint would give you a shot of 475 cfu. That could be a bad day.

[dlskidmore]

@Countymouse 21021 wrote:

Grade A milk has less than 20,000 total bacteria with less than 10 coliforms per ml.

As a clarification, most food standards apply at expiration, not at manufacture time.

Most food standards have a range of acceptable values. For example, Vitamin C breaks down over time in the package, so prepackaged foods are packaged with 120% of the Vitamin C on the label, and have 80% of the amount on the label at the expiration date. Product outside that range would be legally incorrectly labeled, and not salable.

[near horse]

@Tim Harrigan 21045 wrote:

Yes, probably like water where E. coli is mostly an indicator organism, in most cases not likely to cause a problem but but the presence of it is a red flag that other more pathogenic bugs could also be there. But back to the O157:H7, if it was present even at 1 cfu/ml and the infective dose is 100 cfu, 1 pint would give you a shot of 475 cfu. That could be a bad day.

The issue with o157 h7 is since E. coli’s are gram negative bacteria, they can release toxins upon their death and o157 release what is (was) known as shiga-like toxin that can really damage kidneys etc. As far as dose, I don’t know what the minimum requirement is – might not need to be very high. We do some work with Cryptosporidium (a waterborne microscopic protozoan found in cattle) and one can get infected with a few as 10 to 50 organisms. Cattle can be shedding something on the order of 100,000 per mL of stool so yikes.

Isn’t mastitis determined by total SCC – not really a measure of bacterial numbers (at least not directly) but more a measure of an immune response to an infection – just like elevated body temp.

[Andy Carson]

All gram negative bacteria do have lipopolysaccharide (LPS), which is indeed extremely toxic in the bloodstream or body cavities in general. In the gut, which is full of gram negatives in humans and other animals, LPS doesn’t cause an issue. The Shiga-like toxin is the major virulence factor of the famous o157/H7. Interestingly, this virulence factor as well as an important catalase, are encoded by mobile DNA elements. Shiga-like toxin in on a prophage and the catalase is on a plasmid. In other words, these elements can move around very easily to other related bacteria. They just happened to be in serotype O157/H7 more commonly. These elements can also reside in serotype O55:H7, for example, or other e coli strains. To some degree, the serotype is irrelevant. This is not completely true, as there is some evidense that the O157 antigen can mediate attachment to the gut in humans, which would enhance virulence. Also, the plasmid that contains the gene for the O157 antigen also contains the gene for the catalase. Plasmids recombine very frequently, though, so this link is not as strong as it might appear.

As for milk, I really doubt there is much ultity in focusing in so closely on just one organism. It’s probably more useful to see it as an indicator of what else might be there.

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