This article is from the archives of the UB Reporter.

New bacteria responsible for bad breath identified

Published: May 12, 2005

Contributing Editor

Good news may be on the horizon for the millions who struggle with chronic bad breath with the identification by UB oral biologists of several previously unknown halitosis-related bacteria that may represent new targets for treatment.

Developing improved treatments for bad breath relies on identifying such bacteria, said Joseph J. Zambon, professor of periodontology and oral biology in the School of Dental Medicine, who presented the research recently at the International Association on Dental Research general session in Baltimore.

Chronic halitosis refers to a long-lasting, often emotionally devastating condition, not the occasional "garlic breath" problem nearly everyone experiences. The most common cause of chronic bad breath is bacteria living in the mouth.

"Current therapy is aimed at reducing the number of bacteria in the mouth by procedures such as tongue scraping," said Zambon, senior author on the study. "But all the bacteria that can cause the disease are not known.

"What is known," he said, "is that some of the bacteria that cause bad breath produce volatile sulfur compounds, so current therapy is directed against these bacteria. But there are other bacteria in the mouth that can cause bad breath that we are trying to identify. Once the bacteria are identified, we can develop better treatments."

The standard method of identifying the microorganisms causing bad breath is to take tongue scrapings from patients, cultivate the samples in the laboratory and see what develops. In the current study, UB researchers employed a method called Universal Polymerase Chain Reaction, which involves DNA sequencing, to identify bacteria that are difficult or impossible to identify using standard techniques. Zambon said Universal PCR became widely adopted only in the past few years.

Researchers analyzed tongue scrapings from six adults with persistent halitosis, using both bacterial cultures and universal PCR. The cultures revealed significant proportions of six known bacteria (veillonella, actinomyes, Streptococcus parasanguinis, Camyplobacter concisus, megasphaera and neisseria), plus bacteria whose species couldn't be identified, results showed.

By contrast, using Universal PCR, researchers were able to identify those species, plus four others that had not been previously associated with bad breath, Zambon said. Specifically, those were species of atopobium, erysipelothrix, firmicutes and granulicatella, as well as a bacterium called Solobacterium mooreii, which recently was implicated in bad breath, said Zambon.

Additional researchers on the project were Margaret M. Zambon, an MPH student; Doralee S. Gerber, a biochemical pharmacology student; and Violet I. Haraszthy, assistant professor of restorative dentistry and lead investigator on the study.