Scientists recommend 'vaccinating' bacteria against viruses

Posted Mar 31, 2010 by Elizabeth Cunningham Perkins
Protecting industrially-important bacteria from virus and plasmid infections could bring huge economic rewards, a team of scientists at Wageningen University in the Netherlands is reporting at the Society for General Microbiology's 2010 spring meeting.
This key experiment shows the successful protection of a phage-sensitive bacterial strain against a ...
This key experiment shows the successful protection of a phage-sensitive bacterial strain against a virus. Top-right - bacteria growing in the absence of a virus; Top-left - holes in the culture caused by an infecting virus; Bottom - when equipped with specific CRISPR defense system components, the bacteria became resistant to the virus.
John van der Oost
Bacteria have become essential in diverse industries, such as mining, agriculture, environmental clean-up, waste processing and food production, according to Martin J. Blaser, MD, founder of The Virtual Museum of Bacteria website.
Professor van der Oost and his team were able to decipher the biochemical details of a recently discovered bacterial immune defense mechanism called CRISPR, which works differently from the immune systems of higher organisms. CRISPR stands for "clustered regularly interspaced short palindromic repeats" in the DNA of bacteria and some other single-celled microorganisms, found by scientists to be guided by RNA.
One key difference of the CRISPR immunodefense system, according to van der Oost, is that bacterial immunity is inherited, allowing generations of bacterial offspring to be protected before being exposed to specific infectious viruses or plasmids, called bacteriophages.
According to background information provided by the team, the CRISPR process entails certain bacterial proteins detecting and recognizing an invading bacteriophage's foreign DNA and incorporating it into specific locations in the bacteria's genome.
Professor van der Oost explained:
"Storing the information in this way gives the bacteria a lasting 'memory' of the harmful virus that subsequently confers immunity– much like our own immune systems."
"We can exploit this system and expose bacteria to artificial or modified bacteriophages whose DNA could be stored. This would be exactly like giving them a flu jab and protect them against a real attack in the future. For industrially-important bacteria this could be a great cost-saving method to reduce viral infections that may compromise yields of bacterial products. It's a classic example of vaccinating the workforce to increase its productivity."
Professor van der Oost’s presentation is entitled "CRISPR RNA protects prokaryotes against viruses and plasmids."
With over 5,500 members, the SGM is is the largest microbiology society in Europe, open to scientists working in all areas of microbiology.