Bacterial Immune System

Each time one finds a new and innovative biological mechanism one finds another twist and turn. CRISPRs have been explored for a short while but they were understood to be an immune system for bacteria against viral phages. But now there is evidence that they are also used against antibiotics.

Eureka states:

The CRISPR system has attracted considerable attention for its potential uses in genetic engineering and biotechnology, but its roles in bacterial gene regulation are still surprising scientists. It was discovered by dairy industry researchers seeking to prevent phages, viruses that infect bacteria, from ruining the cultures used to make cheese and yogurt. Bacteria incorporate small bits of DNA from phages into their CRISPR region and use that information to fight off the phages by chewing up their DNA. Cas9, an essential part of the CRISPR system, is a DNA-chewing enzyme that has been customized for use in biotechnology. 

The interesting question is that CRISPRs must have developed this capability in bacteria over the past fifty years or so. If so this adds a dynamic to CRISPs that is quite startling.