Staphylococcus aureus N315 was isolated as an MRSA (methicillin-resistant S. aureus) that was
a major pathogen causing hospital-acquired infections in 1982. This bacterium
is easy to acquire antibiotic-resistance, even to vancomycin that is said
to be a last hope of drug to cure MRSA-infected patients. Analysis of the
genome of S. aureus N315 is expected to enhance the accuracy of detection of Staphylococcal infections as well as to reduce the time for detection. Furthermore, it is expected that the mechanisms of antibiotic-resistance will be further investigated so as to develop new methods and techniques to combat with MRSA.
Results of the genome analysis of S. aureus N315 indicate that it contains a plasmid of 25 kb in size. Its genome size is 2.81 Mb with a 32.8 % G+C content, 20 copies of insertion sequences and five transposons. There are three 'pathogenicity islands' within the genome. With a few characteristic exceptions such as the genes involved in sporulation in Bacillus subtilis or those involved in toxin production in S. aureus N315, the numbers of genes in various functional categories are very similar between the two bacteria.
Dr. Hiramatsu (Juntendo univ.)