More superbugs than one

A natural community of bacteria growing on a single grain of sand. Photo by Northeastern  post-doctoral research associate, Anthony D'Onofrio.

A nat­ural com­mu­nity of bac­teria growing on a single grain of sand. Photo by North­eastern post doc­toral research asso­ciate, Anthony D’Onofrio.

Last week I went to an inter­esting event hosted by Northeastern’s Col­lege of Engi­neering that opened my eyes a little wider to the problem of biofilms. These are colonies of bac­te­rial cells that stick to all kinds of surfaces–from the bones in your spinal cord to paper towels in a trash can. It wasn’t until the last few decades that biofilms even came to the atten­tion of sci­en­tists and while they’re respon­sible for the most intractable infec­tions out there (think MRSA), doc­tors have been slow to adapt to a biofilm approach to infec­tious disease.

The National Insti­tutes of Health attrib­utes 80 per­cent of all human infec­tions to biofilms, which, because of their unequaled ability to per­se­vere under harsh con­di­tions, are up to 1000 times more resis­tant to antibi­otics than indi­vidual bac­te­rial cells that float freely through the envi­ron­ment. With $2.5 tril­lion spent on chronic infec­tions each year, it seems like biofilms would be an impor­tant area of research for the United States health­care industry.

Nonethe­less, vir­tu­ally all of the antibi­otics, dis­in­fec­tants, and diag­nostic tech­niques used reg­u­larly by clin­i­cians were devel­oped through research into the “plank­tonic,” or free-​​floating, form of bac­teria. This is prob­lem­atic because that which doesn’t kill a bac­terium only makes it stronger. In the decades since antibi­otics have been suc­cess­fully treating our most vir­u­lent micro­bial foes, their less-​​popular brothers have been sliding by unscathed and are evolving to become even more dif­fi­cult to treat.

Last week’s event, Biofilm Inno­va­tions 2013, was hosted by North­eastern pro­fessor and chem­ical engi­neering chair Tom Web­ster and Richard Long­land, founder of the Arthro­plasty Patient Foun­da­tion and director of the recently released doc­u­men­tary, Why Am I Still Sick?  Fol­lowing a poster pre­sen­ta­tion of biofilm treat­ment and pre­ven­tion research taking place at North­eastern, guests par­tic­i­pated in an inter­ac­tive, mul­ti­media lec­ture series with pre­sen­ta­tions from leading sci­en­tists in the field.

Web­ster pre­sented the work he’s doing with nan­otech­nology to develop antimi­cro­bial mate­rials. He’s done sim­ilar work in tissue engi­neering, where the par­a­digm is mostly well under­stood by now. They can pre­dict exactly how mam­malian cell types will grow on sur­faces dec­o­rated with nano-​​particles based on the energy of that sur­face. But the same cannot be said for bac­te­rial cells. While he has devel­oped sur­faces with nano-​​features that do pre­vent micro­bial growth, much remains to be done to fully under­stand the phe­nom­enon and thus tune it for par­tic­ular needs.

Garth Ehrlich of the Center for Genomic Sci­ences in Pitts­burg argued pretty con­vinc­ingly that taking a genetics approach to diag­nosing chronic dis­ease is the first step in a suc­cessful treat­ment par­a­digm. “If you rely on the cul­tural tech­niques we were taught” said Ehrlich, “you will find that a majority of biofilm infec­tions will come up neg­a­tive.” As a result, many chronic ill­nesses were not thought to be infec­tious. “It held back our under­standing of chronic infec­tions for a very long period of time,” said Ehrlich, whose method of rapidly screening for bac­te­rial DNA is able to iden­tify dozens of bac­teria in infec­tions that turned up neg­a­tive with tra­di­tional methods or only pre­sented the most common bac­teria, like staphylococcus.

Ear­lier I men­tioned MRSA, or Methicillin-​​resistant Staphy­lo­coccus aureus. It’s gotten a lot of atten­tion lately, which is good. But staph infec­tions are just the tip of the ice­berg, said Randy Wol­cott, a med­ical doctor from Lub­bock, Texas who spe­cial­izes in treating “unheal­able” wounds. Wol­cott uses genetic diag­nos­tics to iden­tify the bac­teria in some of the most remark­able wound infec­tions you never want to see. The hor­ri­fying staph infec­tions most of us have heard about by now are pep­pered with a slew of other bac­teria, and until all of them are addressed, the infec­tion will per­se­vere to the point where ampu­ta­tion can become nec­es­sary. He also argued the impor­tance of top­ical antibi­otics, noting that taking a pill dilutes the active ingre­dient throughout the body, so that what shows up at the site of infec­tion is not strong enough to do mean­ingful damage.

Using the DNA approach, Ehrlich also demon­strated that oral bac­teria show up in infec­tions at the knee joint, some­thing that could have never been seen oth­er­wise and put an impor­tant spin on the research of the next presenter. Daniel Sin­delar is the pres­i­dent of the Amer­ican Asso­ci­a­tion for Oral Sys­temic Health. “The mouth is the gate­keeper for the out­side world,” he said, noting that gum dis­ease is a biofilm dis­ease that can spread to the rest of the body. Eighty-​​five per­cent of Amer­i­cans have some form of peri­odontal dis­ease, he told the audi­ence, but only five per­cent of us get treat­ment for it. “How did the mouth get sep­a­rated from the body?” Ehrlich asked. “It’s the pri­mary portal of bad bac­teria.” He pre­sented a few case studies to demon­strate just how serious he was.

Here’s one: a 55 year-​​old healthy, non-​​smoking male of normal weight and cho­les­terol devel­oped sig­nif­i­cantly increased levels of two enzymes that are highly cor­re­lated with heart attack and stroke. This man’s risk of devel­oping a heart attack in the next eight years was 80–90 per­cent. After doing nothing but step­ping up his oral-​​care in some pretty sig­nif­i­cant ways, the man’s LP-​​LPA2 levels reduced to normal and his risk for heart attack dropped by 80 percent.

I’ve been reli­giously flossing and rinsing with Lis­terine ever since.

A lot of mys­teries remain about biofilms, but the con­fer­ence drove home the point — at least for me — that the few things we do know about these nasty infec­tions war­rant sig­nif­i­cant atten­tion from the public health and sci­en­tific com­mu­ni­ties alike.