Testing fabric for bacterial survival - (Aug/02/2008 )

Hello,

I wonder if someone could help me. I have been asked to test a new washing detergent being used at my place of work. The detergent claims to kill bacteria in a 40oC wash as well as disinfecting the interior of the washing machines. Laboratory tests have already been carried out however they want to know how well it actually works when used in the workplace.

Has anyone got any suggestions about the best way to test the fabric after it has been washed? I apologise now, I am a bit of a novice, but I'll appreciate any help you can give me.

Thanks,
Hermione

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Hermione,

thats a good question.

I think you could take samples of the clothes when they are still in the machine (at the end of the washing cyle, when you are about the remove the clothes) and then test these samples in the lab. You can also swipe the interior of the machine and test this too.
You can use those "sticks" that medical eximnators also use to take dna samples.
Put them directly in a closed tube so that there is no contamination.

Other then that, I do not see how to test the material.

A lot of the senior members of this forum are on holiday so they might not respond quickly.


An other thing I wonder is : the detergent is especially created to kill certain bacteria that are used in a lab? (labbacteria) (to clean labclothes?)
I guess it is like this , well then you can also do this: besides taking samples directly after wahsing, take also some samples after you removed the clothes and placed the clothes in a bin or something (a place where there should be no contamination with labbacteria) and let the clothes stay for a while there.
After the clothes stayed there for a while take the samples , and then innoculate those samples and check what kind of bacteria are on the clothes. If you can only find bacteria that are very common for the room or for a normal atmosphere then the detergent works.
If you however still find "special" bacteria then you know that the detergent did not work.

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Hi, thanks for your reply.

The detergent is designed for use in hospitals and nursing homes. The information that is included with the products says that is has been proven to kill MRSA, C. diff and your usual HCAI. The company wants to know how well it works in smaller nursing home laundries, it has already been tested in hospital laundries.

To be honest I think I am a little out of my depth here!

Hermione

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Well Hermione, if youn are specificaly testing for those bacteria then there should be no problem with the method I described.

You do however need to know a way to determine wich bacteria you have on your medium, but I suppose you know that.

And like I said: test a sample from clothes directly out the washmachine and a sample from clothes that have been in the room for a while (eg. in the room where they put the washed clothes?)
And also take samples from "dirty" clothes (meaning those that have been worn during the day etc..)


and check how many micro-organisms you have.

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Look up the Petrocci Clarke method.

Does the product indicate an active ingredient?
I'd be very surprised at the C. diff claim. The bug is a spore former and it's hard to kill - tho some have been burned using protocols that deleivered primarily veg cells. Can yiou name the product?

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Here's a link to the EPA website for Petrocci and Clarke laundry efficacy. If the product is marketed in the US - this is the test by which the marketer must have demonstrated efficacy.

http://epa.gov/oppad001/dis_tss_docs/dis-13.htm

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the link is great, thank you jorge1907!

Hermione, if you are up to testing it for a company look for a standard protocol. Everything else is nice data for them but peoploe are keen for standardised tests (and this is what makes them comparable, otherwise everybody could fool around until he gets the result he wants)! you can look if you find some ASTM or ISO standard for your problem!

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Thanks for all your help!

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