Researchers Describe Molecular Switch Controlling “Chameleon” Bacteria

Researchers Describe Molecular Switch Controlling “Chameleon” Bacteria 150 150 Abbie Miller

Closing the gap on developing a vaccine for middle ear infections.

Researchers at Nationwide Children’s Hospital in Columbus, Ohio, and Griffith University’s Institute for Glycomics in Australia have discovered groundbreaking evidence that will help vaccine developers in their search for a vaccine against multiple infections of the respiratory tract, including middle ear infections. The research, published today in Nature Communications, describes how Haemophilus influenzaerandomly changes gene expression in hundreds of locations, in response to stimuli.

Phase variation – the rapid change in expression of multiple genes with one molecular switch – has created a moving target confounding researchers focused on vaccine development. “When you study one gene or protein at a time in isolation, which is how we often tend to do this research, you can be completely misled if you don’t consider phase variation via this unique mechanism,” says Lauren Bakaletz, PhD, director of the Center for Microbial Pathogenesis at The Research Institute at Nationwide Children’s Hospital. “These organisms are often called ‘chameleons’ because they can rapidly change from one form to another.”

According to Michael Jennings, PhD, principle research leader at the Griffith University’s Institute for Glycomics, this research enables researchers to understand the lifestyle of the microbe and its adaptation to humans as hosts. Ultimately, this research provides direction for identifying which cell surface proteins on the bacteria are good targets for vaccine development.

“This is a very important stepping stone to a vaccine and will save developers a considerable amount of time and money,” says Dr.  Jennings.

“The Jennings lab at Griffith University’s Institute for Glycomics has been describing how several bacterial species that cause human diseases have a unique way to rapidly change gene expression throughout their genome,” explains Dr. Bakaletz, who is also vice president of basic sciences at The Research Institute. “Our lab has been looking at the biology and pathobiology of these organisms to predict how the organisms react in a mammalian system, particularly the human host. When you put these two lines of inquiry together, the result is really powerful.”


Atack, JM. Srikhanta YN, Fox KL, Jurcisek JA, Brockman KL, Clark TA, Biotano M, Power PM, Jen FEC, McEwan AG, Grimmond SM, Smith AL, Barenkamp SJ, Korlach J, Bakaletz LO, Jennings MP. A biphasic epigenetic switch controls immunoevasion, virulence and niche adaptation in non-typeable Haemophilus influenzaeNature Communications. 2015 Jul 28. [Epub ahead of print].

About the author

Abbie (Roth) Miller, MWC, is a passionate communicator of science. As the manager, medical and science content, at Nationwide Children’s Hospital, she shares stories about innovative research and discovery with audiences ranging from parents to preeminent researchers and leaders. Before coming to Nationwide Children’s, Abbie used her communication skills to engage audiences with a wide variety of science topics. She is a Medical Writer Certified®, credentialed by the American Medical Writers Association.