people,

 

This has been bugging me (no pun here), for years- so much talk/scare about ingesting one or 2 or even 1000 cells of e coli accidentally say, by eating some undercooked beefburger which had been infected/contaminated- such that one has to wonder just how much e coli does one have to "eat" to become ill (overwhelmed). How many colonies per plate(?). How much e coli (or salmonella. for that mater) should the healthy immune system be able to control/attack/kill/surround/isolate/"neutralize" by the white blood cells?

 

 

Immune system subject for sure. How many - in terms of however the micro people like to "count" such bacteria. (maybe this is for the micro forum(?)).

 

Thanks

Edited June 21, 201411 yr by pippo

What you are looking for is the infectious/infective dose. However it is not that is not easy to generalize as it depends on the strain, the pathway of infection an your immune system (as well as native flora).

For example, oral doses are usually relatively high as many bacteria are killed during passage through stomach and once in the gut they are heavily outcompeted by your native flora. But if they get into the bloodstream via a wound, you need less bacteria to cause issues.

It should also be added that many (most?) E. coli strains are harmless, though there are nasty exceptions. Accordingly the most aggressive E. coli can establish infections with as little as few hundred cells (e.g. EHEC), whereas some are more in the order of millions (EPEC).

Thanks, Charon. So, then, practical/hypothetical example, lets say one ingests some e coli (the strain typically of concern, from contaminated beef) by using a spoon previously in contact with some pre cooked beef , to eat some food. Is that in your opinion enough to overwhelm your flora in stomach?

 

Second example, say one opens door to bathroom by turning the door knob, does NOT wash hands afterward, then accidentaly ingests this e coli (human strain, of course) by having lunch after that incident. Enough for sepsis?

 

Thanks

Well, as I mentioned it would require to have pathogenic E. coli strains to begin with (e.g. EHEC vs EPEC). Furthermore, it depends how fresh and well the beef was stored before the incident. For example, raw beef that is well processed is typically fairly safe and can be eaten raw (see. e.g. steak tartar) with relatively rare incidences. Typically the worst you get is a bit of passing diarrhea.

 

In the end, exposure to bacteria only increases chances but is never a sure thing. However doorknobs and similar are very unlikely to lead to something serious, even if you licked the knob (and certainly not sepsis, that is a completely different issue which would require severe untreated infections).

 

It would be different if you started doing it everyday, for example (although you may prime your immune system to fight it).