Spores: Transmisssion of C. diff.

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Bobbie
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Spores: Transmisssion of C. diff.

Postby Bobbie » Wed Mar 28, 2007 11:59 am

Allison submitted this.
Posted: Mon Mar 26, 2007

Interesting thread. There never seems to be easy answers when it comes to cdiff, and the animal to human transmission issue is certainly no different.

Some things to think about:

The term "re-infection" is probably a misnomer, because of cdiff's ability to sporify. There is a difference between relapsing cdiff, and recurring cdiff, though the two terms are often used interchangably by physicians and also may appear in medical literature as one and the same thing.

Because truly relapsing disease is not all that common, many physicians are tempted to think when it happens, that it's a "re-infection" of cdiff and may look for a source outside of ourselves. That's easy to justify in hospitalized patients where a variety of cdiff strains are endemic, but not so easy to do in the community.

Since there are many folks with truly relapsing disease who do not own pets, it may be faulty thinking to assume an animal is a resovoir just because it lives with a cdiff patient and that person is not getting over the infection. For relapsing disease, it's possible, but not all that probable. Testing for strain could help clarify.

For recurring disease, it's might be more likely. If I were to get a cdiff infection, see it resolve with treatment, but then get it again (with or without antibiotic use), I'd start looking hard for another source outside my own gut. Again, testing for strain can clarify. To add to the confusion: some patients who relapse (never have a period of time off meds without symptoms), can still be found to be infected with a different strain from the one that caused the intial infection! In those instances, the line between relapsing and recurring is less clear and shows it is possible to have one infection, and get a different one on top of that. That was always deemed unimportant in the past because treatments were effective against all toxin-producing strains.

About the spores: Cdiff bacteria doesn't "automatically" sporify. Aquisition of the bacteria (or it's spore form), does not produce the spore state within the gut. Sporification is a defense mechanism and the bacteria is perfectly happy to remain in it's active, vegetative state (or revert to that state if a spore is ingested and it likes the environment). It does not want to go into spore mode. It cannot grow or reproduce in that state and will revert to protecting itself by sporifying only if there is a threat to it's survival. That threat is usually treatment with flagyl and/or vanco.

So "shedding spores" in true cdiff carriers without symptoms is probably another misnomer. With no treatment to threaten survival, it is the vegetative form of cdiff that may be shed in stool and then it may sporify to remain alive if not transmitted to another host quickly.
Last edited by Bobbie on Sat Aug 02, 2014 5:40 pm, edited 4 times in total.
Reason: updating

Bobbie
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Postby Bobbie » Wed Mar 28, 2007 12:04 pm

Allison submitted this.
Posted: Mon Mar 26, 2007

Well, I think it depends on how the term "infectious" is applied.
Since the toxins themselves don't cause any infection, but are a by-product of it, in a very technical sense, toxin postive stool (without additional information) does not outright prove the sample tested is infectious with cdiff bacteria.

But, since the bacteria must be present in the colon to produce the toxins, those toxins are "clues" that the active bacteria can also be present in stool. That would make it infectious on assumption and is a good rule to go by when testing doesn't occur for the presence of actual bacteria. In general, I'd say what normally lives inside the colon will venture outside..maybe go for a bus ride. Stool is the bus.

If there is no toxin present, another assumption is made, and that assumption is based on the theory that there is not enough bacteria colonizing and viable enough to produce the toxins.

Cdiff really suffers from a lack of definition and that is the main reason why it's not a reportable disease. The changing epidemiology will eventually alter the definiton by default, me thinks. But for now, cdiff is really not an infectious disease unless it actually causes infection. It does not do this in everyone...even those with high exposure risk who may even be colonized. Asymptomatic carriers harbor bacteria that may or may not produce toxin postive stool occasionally, but they cannot be considered to actually have cdiff disease, and by current definition, are NOT infectious.

Personally, I'd operate on the assumption that all stool itself is infectious because it contains so many different bacteria that have the potential to be pathogenic, whether it contains cdiff bacteria or not!

2.True. And they can also be toxin negative if the bacteria isn't viable enough to produce the toxins. "Being kept in check", so to speak.

3. I imagine this is also true, and under these circumstances, a great deal has to do with host defenses. The effects of colonization are quite individual, and which strains, and just how much bacteria is present, certainly plays a role in whether or not the bacteria gets out of hand enough to cause illness (along with other important factors like immune gut response, and which class of antibiotics were taken to precipitate the infection, if there were any taken at all).

Bobbie
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Postby Bobbie » Sun Oct 28, 2007 12:12 pm

Christina provided this info. re. the transmission of C. diff.

http://multimedia.mmm.com/mws/mediawebs ... SJCOrrrrQ-

Bobbie
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Postby Bobbie » Mon Dec 31, 2007 2:42 pm

Allison provided this info.

Hi Connie,

You have a good understanding of cdiff. A few points:

"I guess my question is, just how many spores are there, do they continually reproduce themselves..."

The cdiff bacteria cannot reproduce when it's in the spore state. It can only grow and multiply during it's vegetative (bacterial) cycle. The spores will not hatch if conditions are not favorable, so the idea that they continually reproduce themselves only applies if gut conditions allow it.
The spore/hatch cycle becomes insignificant once the environment is hostile to the bacteria...best way is a full set of indigenous 'good" bacteria.

"and if left alone (no flagyl or vanco) is there any chance that probiotics alone can eventually kill them off, if they continued hatching but did not form new spores?"

All the oral probiotics can compete with cdiff on a temporary basis, but they don't kill the bacteria...only antibiotics can do that. In mild cases, it is entirely possible to "beat" the acute infection without meds, and that is the best way to avoid a cycle of relapses (if possible).
In case of more severe disease, it is not often possible, or safe, to try this until such a time that symptoms are mild and deemed unimportant clinically.

If you can stay off the meds, it should not be necessary to take the probiotics indefinitely. Time and normal living will allow the indigenous bacteria to colonize and right the imbalance.

If your symptoms are mild and you feel relatively well, time is the best method to avoid another relapse. With your doc's approval, I would keep a close eye, and go for the vanco in the event things get worse or you have more indication of full blown relapse (fever, blood, frank diarreah, "flu-like" symptoms).

Nancy provided this info.

Connie,
Here is my understanding. Flagyl or vanco do not cause spores to form. What they do is kill the growing cdiff bacteria, but they do not kill the spores. They also kill the good bacteria, as you say.

Spores are very hardy. I don't think anyone knows how many spores each person might have. Spores do not reproduce, but they can exist for a long time. And they can hatch into growing bacteria, in the absence of Flagyl or vanco. The growing bacteria reproduce, meaning they can make more growing bacteria, and they can also make spores.

Probiotics do not kill spores. What they do is put good bacteria in our guts, and the good bacteria out-compete the cdiff bacteria. That is why antibiotics are so bad for us, because they kill the good bacteria, so there is nothing left in our guts to out-compete the cdiff bacteria (or any cdiff spores that might hatch).

FYI, pulsing can work sometimes because you let spores hatch on days you don't take vanco, then you take vanco and kill the growing forms. Then you stop vanco and let more spores hatch, then you kill these growing forms, and so on. Eventually you run out of spores.


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