The development of antibiotic resistance is a major concern for many in the medical industry. Bacteria quickly develop resistance to very powerful antibiotics, rendering them useless. However, new research shows that it may be possible to prevent the evolution of further antibiotic resistance if the SOS response of bacteria can be permanently switched off.
The SOS response is the major mechanism by which most bacteria repair severely damaged DNA. However, the SOS response can also create mutations in the DNA if an extreme environmental stress, such as an antibiotic, is applied to the bacteria. This increases the ability of the bacteria to survive the stressful conditions, for example by developing antibiotic resistance. Previously it was believed that the streptococci bacteria lacked this response. However, recent research shows that an unusual form of the SOS response is present in streptococci bacteria.
In most bacteria, the SOS response is switched off by the LexA protein. However, under stressful conditions the action of the LexA protein is prevented. In contrast, the SOS response of streptococci is regulated by the HdiR protein. Like LexA, HdiR inhibits the SOS response in most environments but is deactivated in stressful environments. Therefore, further research will determine if preventing the deactivation of LexA or HdiR can stop the evolution of antibiotic resistance.
Written by: s4119320
References:
1. Varhimo, E., Savijoki, K., Jalava, J., et al (2007). “Identification of a Novel Streptococcal Gene Cassette Mediating SOS Mutagenesis in Streptococcus uberis.” Journal of Bacteriology, 189(14): 5210-5222
2. Cirz, T., Chin, J., et al (2005). "Inhibition of Mutation and Combating the Evolution of Antibiotic Resistance." PLoS Biology, 3(6): 1024-1033
3. Bardi, J., (2005). "To stop evolution: New way of fighting antibiotic resistance demonstrated by Scripps scientists." FROM: http://www.eurekalert.org/pub_releases/2005-05/sri-tse051805.php
