Does the bacteria count increase if you do not wash the bottle between uses? ( I need 3 articles)?

I really need to have 3 articles answering this question or giving background info on this question. It would be greatly appreciated. :)

Does the bacteria count increase if you do not wash the bottle between uses? ( I need 3 articles)?
I don't think I can find any articles on that, sorry, because it's kind of intuitive. Bacteria are all around us, especially in the air. That is why we always work under the hood of the flame to discourage contamination. If you aren't even in an aseptic technique there there is a high chance there will be contamination in the bottle.