Dogs bring swarm of bacteria into your home

Your loyal pooch may be bringing a whole world of bacteria into your home including certain bugs that are rarely seen in households without dogs, a new study has found.
New research from North Carolina State University and the University of Colorado shows that households with dogs are home to more types of bacteria.
"We wanted to know what variables influence the microbial ecosystems in our homes, and the biggest difference we've found so far is whether you own a dog," said Dr Rob Dunn, an associate professor of biology at NC State and co-author of a paper describing the work.

"We can tell whether you own a dog based on the bacteria we find on your television screen or pillow case. For example, there are bacteria normally found in soil that are 700 times more common in dog-owning households than in those without dogs," said Dunn.
However, researchers said these microbial differences may be important. For example, it's known that women who have a dog in the home when pregnant are less likely to have children with allergies.
This is a correlation - there's no known causal link between the presence of a dog and the absence of allergies - but it has been hypothesised that the difference is related to the women's exposure to a wider variety of microbes, researchers said.

While this study doesn't demonstrate a causal link, it sheds more light on the subject, showing that dogs have a major influence on which microbes are found in our homes.

Citizen scientists in 40 homes sampled nine common surfaces to help researchers determine what kinds of bacteria lived there, and in what relative numbers. The nine surfaces were wiped with sterile swabs from which researchers collected DNA to see which organisms were present.
The nine surfaces were the television screen, kitchen counter, refrigerator, toilet seat, cutting board, pillow case, exterior door handle, the trim around an interior door and the trim around an exterior door.

The study found 7,726 phylotypes, or kinds, of bacteria in the homes. The study also found that each of the locations sampled harboured its own unique collection of bacteria.
Researchers were able to group the sampled surfaces in the homes into one of three general habitats: places we touch, places our food touches and places that collect dust.
For instance, the types of bacteria found in refrigerators, on kitchen counters and on cutting boards tended to be similar - because they were primarily linked to our food.