Some of the interesting stories researchers were discussing at this years American Society of Microbiology meeting in San Francisco.

Are air microbes alive?

Air contains a multitude of bacteria, up to 10,000 per cubic meter, which researchers have assumed exist in spore or dormant forms. To test this assumption, investigators from Rutgers University in New Brunswick, New Jersey, collected air from several locations from around the state and tried to increase the numbers of microbes using a spare liquid culture containing water and small amounts of salts, acids, and alcoholsconditions that mimic the compounds typically found in the air. The researchers then aerosolized successfully growing bacterial cultures using a reactor that they designed and built in-house, and recorded the amount of the carbon isotope 13 that was incorporated into the bacterial DNA a proxy for growth. Although the results showing some bacterial growth in aerosolized cultures are tentative, according to a press release, the investigators are hopeful that further research will provide another example of bacteria thriving in inhospitable conditions.

Bacterial virus fights coral disease

Coral reefs are plagued not only by bleaching events in which they dump their photosynthetic symbionts in response to stress, but also by bacterial disease that can spread rapidly through a colony. Researchers cant immunize coral against the bacteria because their immune systems are too rudimentary, and antibiotics cant be applied effectively in open water. Instead, researchers have investigated using a virus that specifically infects and kills the coral bacteria responsible for white-plague-like coral disease in the laboratory with success. A group from Tel Aviv University recently tried the approach in the Gulf of Aqaba, bordered by Egypt, Israel, Jordan, and Saudi Arabia, and found that the virus successfully slowed disease progression and transmission to new corals. For untreated corals, on the other hand, the disease continued to spread throughout the coral tissue and to neighboring corals, killing 65 percent of tissue in 28 days. An added advantage of the approach, the researchers found, was that the virus would replicate as it killed disease-bacteria and spread to other bacterially-infected corals, but would diminish when the bacterial disease was under control, mitigating the possible spread of an introduced virus.

Cigarette smoke makes bacteria more virulent

Researchers from Columbia University in New York have found that cigarette smoke changes the properties of commensal bacteria, putting smokers at greater risk of their microbiome becoming dangerous. Staphylococcus aureus is part of our normal flora, but it can also cause disease. Exposure to smoke altered Staph physiology, increasing its ability to stick to human cells as well as inanimate objects; increasing its genetic mutations, which could lead to antibiotic-resistant strains; and enhancing its ability to grow as a biofilm. Chronic infections are often caused by bacteria that grow as biofilms, and researchers found that their observations were consistent with the increased incidence of difficult-to-treat infections with smoke exposure.

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Roundup from Microbiology Meeting