'Rare' and 'unusual' bacteria discovered on Muni by SFSU researchers

In 2011, Darleen Franklin, a biology researcher at San Francisco State University, was commissioned by The Bay Citizen to take samples of whatever was hiding in the then-plush BART seats. The findings were frightening, and likely contributed to BART's eventual decision to replace the seats with an easier to clean vinyl covering.

In April 2016, she (with a team of researchers) reprised their duty again, re-testing BART's seats as well as Muni's, and the results are now in, via KTVU.

To their surprise (and disgust?), Muni's seats yielded some odd findings. Franklin found a "hard to identify" bacteria that her team eventually discovered to be a strain called "Pigmentiphaga." The bacteria, found on the 28 bus line that runs near Golden Gate Park and SF State, is extremely rare, only ever being found in waste water from South Korea, the South China Sea, and in one weird case, a 6-year-old patient in Manitoba, Canada.

Franklin tells KTVU that they're not sure yet if the strain is dangerous to Muni riders, saying that in the case of the young Canadian girl, it was "difficult to assess the clinical relevance of this microbe as it pertains to human health."

A pedestrian walks past a Muni bus on Van Ness Avenue in San Francisco, Calif. on Thursday, Aug. 27, 2015. Muni is getting ready to roll out a second round of major service improvements systemwide. A pedestrian walks past a Muni bus on Van Ness Avenue in San Francisco, Calif. on Thursday, Aug. 27, 2015. Muni is getting ready to roll out a second round of major service improvements systemwide. Photo: Paul Chinn, The Chronicle Buy photo Photo: Paul Chinn, The Chronicle Image 1 of / 18 Caption Close 'Rare' and 'unusual' bacteria discovered on Muni by SFSU researchers 1 / 18 Back to Gallery

John Haley, a representative for Muni, maintains that buses are "definitely safe" to ride; an SFMTA spokesman backs him up on that as well, saying that San Francisco's Department of Heath found it was "non-pathological" and "nothing to worry about."

It is, however, irrefutably icky.

On the other hand, BART, thanks in large part to a decision to move to the vinyl material, has substantially improved the sanitation of its seats. Unlike years before, there was "no presence of fungi, fecal bacteria" found on the seats, which is great news for people who don't like gross things.

In the meantime, Franklin and her team are planning to look more into the Pigmentiphaga strain. As she says, "more research has to be done on it."

Read Franklin's report here.

Edit: Franklin has provided SFGATE with the following update:

"Conclusion: From this study the take home message for our commuters would be that the BART new seat material today is much better than the old cloth seats at preventing transportation of the unwanted tiny passengers in our microbiome. No human pathogens were detected in this qualitative microbial study, basic hand washing / hand sanitizing and keeping your hands out of your open orifices (eyes, mouth, nose etcetera) when on any public transportation is still the best way to prevent infection. In addition the procedure described in this study could be used to continue tracking public health disease in the SF Bay Area public transit system or microbiome studies."

Additionally, she notes that the Pigmentiphaga does not pose a health concern, as "with poor and observed slow growth in 37ºC, they don't pose a health concern in this study."