Bacteria in drinking bottles: a question of hygiene
Did you know that more bacteria live in your water bottle than in a dog bowl? Reusable bottles are a common companion in everyday life, yet their hygiene is often neglected. A microbiologist explains why it is important to clean the bottle regularly and correctly.
A recent study showed that, on average, 14 times more bacteria live in a drinking bottle than in a dog bowl. On average, the reusable bottles examined contained 20.8 million colony-forming units. These units indicate how many viable microbes are present on a surface. That is 14 times more bacteria than in a dog bowl and 40,000 times more bacteria than on a toilet seat.
It may seem surprising that so many bacteria can live in bottles that contain only water. "Bacteria live everywhere: in us, in the tap and in the coffee machine too," says Martin Loessner, professor of food microbiology. "The bottle touches the mouth. Food residue or stomach acid can get into the water. This provides a nutrient-rich environment in which bacteria can multiply." Bacteria that get into the bottle from your own body are not a problem, but other germs can get into the bottle too.
The US study mainly found gram-negative bacteria (e.g. Salmonella, meningococci, Borrelia and Legionella) and Bacillus. Some forms of Bacillus can cause gastrointestinal illness, while certain gram-negative bacteria can cause infections that are becoming increasingly resistant to medication.
It is important to clean the drinking bottle daily with washing-up liquid and a bottle brush by hand, or in the dishwasher. But even with regular cleaning, a biofilm can form in the bottle, because the often small opening of the bottle, or the area under the sealing ring, means not all areas can be cleaned.
We recommend disinfecting monthly with biostream® asepticaPRO or biostream® ZERO. Add 10 ml of biostream® concentrate to 1 litre of water in the bottle. After a contact time of 3 hours, you can rinse the bottle with fresh water and use it again with a clear conscience.