It was previously thought that evolution was a random process due to DNA mutations that just randomly happen. Recent research suggests otherwise, it is now thought that the evolution of resistance to antibiotics in some microbes isn’t as ‘random’ as previously thought.
Many microbes react to environmental stress, such as an antibiotic like ciprofloxacin, by undergoing the SOS response. Ciprofloxacin causes double stranded breaks in DNA and affect the DNA gyrase. It is now thought that many microbes, including S. aureus, intentionally undergo SOS to create greater genetic variation in the affected site in hope that resistance will ‘evolve’.
But what makes S. aureus unique? And could possibly make it develop resistance to so many antibiotics so easily? This article suggests that the SOS response is not the only phenomena that the cell undergoes when under stress. Can antibiotic resistance to an antibiotic such as ciprofloxacin go as far as to affect the metabolism of the bacteria too?
Could a change in a metabolic pathway such as the TCA cycle have such a large effect on the virulence, persistence and resistance of the bacteria? The article by Ryan T Cirz et. al. suggests that this is a major factor in this bacteria’s ability to develop antibiotic resistance so easily.
http://portal.isiknowledge.com.ezproxy.library.uq.edu.au/portal.cgi/wos/?Init=Yes&SID=4C8E3O2HHghmAGok4fA
Reference
Cirz RT (Cirz, Ryan T.), Jones MB (Jones, Marcus B.), Gingles NA (Gingles, Neill A.), Minogue TD (Minogue, Timothy D.), Jarrahi B (Jarrahi, Behnam), Peterson SN (Peterson, Scott N.), Romesberg FE (Romesberg, Floyd E.), 2007 ‘Complete and SOS-Mediated Response of S. aureus to the Antibiotic Ciprofloxacin’ Journal of Bacteriolog Vol 189 (2) pages531-539 J
by Daniel Kluver (41184239)
