12 replies to this topic

[Uncia]

Hello! I work in a tissue culture lab where we work with various non-human species. About a year ago we began having unusually large numbers of cell lines come up contaminated with fungus.
We recently seem to have gotten it mostly under control by increasing the frequency of incubator cleaning and keeping older flasks out of newly cleaned incubators.
So things are looking up. My problem is that as part of dealing with this problem, the technicians (which includes me) asked that we change our lab practices to help prevent such a thing from happening again. Our suggestions included wearing lab coats and gloves in the TC room. (Previously, nobody wore lab coats, and we technicians only wore gloves inside the hood, but as it became clear we had a serious contamination problem, the techs started wearing coats and gloves pretty much any time we are in the room, and absolutely every time we touch the incubators, hoods, or flasks).
For reasons that are not clear to me, the lab manager and that person's manager (who sometimes works in the lab as well) feel that wearing gloves wouldn't help prevent fungal contamination and may even promote it, and that the purpose of gloves is to protect ourselves (for example, when working with primate material) rather than protect the cells from us.
Although I would like to see people wear gloves in the TC room all the time, that request was eventually ratcheted down to asking that people please wear gloves when handling OTHER people's cells, and opening incubators that are shared with other people (as most of them are), to help avoid transferring contaminants into the incubators and onto the flasks. So far that request has also not been honored. Because they are my superiors I can only do my best to persuade them to change their behavior.
So...a) does anybody know of a paper or other documentation providing evidence that gloves actually help prevent cell culture contamination? I haven't been able to find anything specific so if anybody could toss me a citation I would love to track it down and bring it to my next meeting.
And I know this isn't a group therapy session but I would love to have a tiny bit of reassurance that I am not making unreasonable demands here from the standpoint of preventing contamination. You know how when people act like you're crazy for long enough you eventually start to doubt yourself?
Thanks for taking the time to read this.

[bob1]

Papers on infection control in hospitals should be relevant to this situation. There should be plenty out there showing that glove use reduces the spread of infections.

This might help (haven't read the full paper though):

How long do nosocomial pathogens persist on inanimate surfaces? A systematic review
Axel Kramer, Ingeborg Schwebke, and Günter Kampf
BMC Infect Dis. 2006; 6: 130. Published online 2006 August 16. doi: 10.1186/1471-2334-6-130.

[mls677]

Have you thought about determining what type the fungus is? Sometimes that can help determine where the contamination is coming from (ie. hands, shoes, clothing, etc). I don't think it's unreasonable to wear gloves when ever touching things in the cell culture room. We do that in our room as well to make sure that we don't contaminate any of the surfaces that we might later touch with gloves that will be handling our cells.

[Uncia]

bob1, on 24 November 2010 - 02:48 PM, said:

Papers on infection control in hospitals should be relevant to this situation. There should be plenty out there showing that glove use reduces the spread of infections.

This might help (haven't read the full paper though):

How long do nosocomial pathogens persist on inanimate surfaces? A systematic review
Axel Kramer, Ingeborg Schwebke, and Günter Kampf
BMC Infect Dis. 2006; 6: 130. Published online 2006 August 16. doi: 10.1186/1471-2334-6-130.

Thanks for the reference! I'll look into more infection prevention stuff. At least if they acknowledge that pathogens are regularly transmitted by human hands...that would be a start.

[Uncia]

mls677, on 30 November 2010 - 07:36 AM, said:

Have you thought about determining what type the fungus is? Sometimes that can help determine where the contamination is coming from (ie. hands, shoes, clothing, etc). I don't think it's unreasonable to wear gloves when ever touching things in the cell culture room. We do that in our room as well to make sure that we don't contaminate any of the surfaces that we might later touch with gloves that will be handling our cells.

We sent it off for testing and much of it appears to be Aspergillus, which from what I can find on the internet seems to be on and in everything. We had new HEPA filters put in above the room which didn't seem to help much.
Thanks for your input, I'm glad I'm not just weird. The lab manager has now begun wearing ONE glove. Baby steps, I guess.

[leelee]

I tend to agree with your lab manager here- I don't know that gloves will help in this case.
If you have staff that are careless enough to introduce contamination into their cultures, chances are they will be careless when wearing gloves too.

The only way gloves will help is if wearing gloves changes the behaviour of the wearer- eg because they have gloves on they won't tie their shoe, or pick something up from the floor then handle cells, or whatever. Which I think does happen- I know I am more concious of what I touch when I have gloves on.

[lab rat]

I agree with leelee on the behavior modification, but I also believe that wearing PPE will protect your cells from anything you are carrying. It was the GLP of the diagnostic lab I used to work in--when working in the clean room (including when establishing primary cell lines), we wore a dedicated lab coat and gloves at all times. Fungal contamination was rarely an issue.

[Uncia]

I agree that behavior is really the critical issue. I tend to assume that a clean glove is, in theory, better than even a recently washed hand as far as transferring contaminants onto flasks, because of skin cells and oils and things that might be hiding under one's nails. But that is just an intuitive idea and not based on anything empirical.
Regardless, they seem quite determined not to wear them, so I'm just going to hope they are washing their hands before handling common items in the lab.
Thank you for the responses!

[lab rat]

Hi Unica,

Have you seen this technical bulletin from Corning? A direct quote:

"Another source of particulates and aerosols is laboratory personnel...Dry flaky skin is another source of contamination laden particles; this common condition is aggravated by the frequent hand washing required in the laboratory. Some laboratory personnel shed yeast-containing particles for several days following bread making or beer brewing at home. Attempts by these persons at cell culturing during this period have routinely ended in failure due to yeast contamination."

Have your lab manager try this for his- or herself.

[lab rat]

The splash page for the bulletins on cell culture: http://catalog2.corn...e|Contamination

[LabLackey]

Just a thought...would dousing your gloves with 70% ethanol curb contamination? We are required to wash our gloves before touching anything in our TC room...incubators, reagents, cells, everything! Would that help with a fungal infection?

[Uncia]

Well, we've narrowed it down somewhat. What I think now is that the contamination is not occurring during the actual cell culturing, but is getting into the cultures while they are in the incubator. The only thing that seems to help is more frequent incubator cleaning. On some flasks I can see fungus growing on the outside of the flask and up the neck. I clean all my flasks with ethanol before I put them back in the incubator, but if the incubator goes too long between cleanings, the flasks randomly pop up with contamination, and it's always in the neck and cap. Because the incubators have a sterilization cycle, I suspect that fungus is being reintroduced into the incubators between cleanings, but maybe the "sterilization cycle" is just a misnomer.
The Corning bulletin describes exactly this situation (fungus growing into long-term cultures from the outside of the flask)...thank you, it's the first thing I have seen that matches our problem so closely and that actually says that skin cells and things sloughing off your hands and sleeves may contain contaminants. I'm going to start ethanoling off the incubator door & handle before I open it so I'm not transferring stuff onto my flasks from people who open the incubator without gloves. Right now I also have to carry cells between three different rooms so those door handles could easily be a source of contamination as well. I'm just going to start ethanoling the heck out of everything including my gloves.
Thanks everybody for the link and the suggestions!

[briguy7]

Make sure you change labcoats for clean ones often--just wearing a labcoat isn't helpful if it is covered in spores!