Harvesting bacteria shed by C. elegans

In my experiment I will be infecting C. elegans with Salmonella, which are known to be able to survive in the C. elegans gut and to be viable
after being defecated by the worm.

I want to harvest the bacteria immediately after they are defecated. I was wondering if someone has any ideas on how I can achieve this.
I am planning to use a 20 micron sieve test, wash the worms constantly, and then concentrate the bacteria that have been washed off. Any other ideas?



Look at the recent paper by Kawli and Tan in Nature Immunology. I thought their experiment for measuring live bacteria from the worms guts were quite elegant. I think it could probably be adapted to find what you are looking for.