The number of known antibiotic-resistant genes has climbed to at least 89, up from just 15 in 1991. These genes have led to the reemergence of diseases like tuberculosis. Now, an old hospital bug, methicillin-resistant staphylococcus aureus (mrsa), is making an alarming comeback as a superbug. It’s one example of how bacteria can mutate into a drug-resistant form and become more aggressive. mrsa is a type of staph infection that’s been making headlines in the United Kingdom, where the rate of hospital infections has been rising dramatically.
In the United States, a different strain of mrsa than that found in hospitals has also developed. It is circulating through communities around the nation, affecting younger people in particular who “do not have predisposing risk factors” (Journal of Clinical Microbiology, December 2004). Dr. Francoise Perdreau-Remington, an infectious-disease specialist at the University of California in San Francisco, claims it is “now spreading all over California” (San Jose Mercury News, California, January 26). Dr. Daniel Skiest, an infectious-disease specialist at the University of Texas Southwestern Medical Center in Dallas, admits, “We never thought it would get out of control like this” (Dallas Morning News, Dec. 12, 2004). In fact, “The numbers of mrsa are rising exponentially nationwide,” said Dr. Marion Kainer of the Tennessee Department of Health (Tennessean, Dec. 29, 2004).
Moreover, in Ireland, the superbug has been found in animals (cats, dogs, horses, rabbits and even a seal) for the first time, which implies that it can be transmitted between humans and animals. As biology Professor Hatch Stokes of Macquarie University suggests, “The rise and spread of antibiotic resistance can only continue” (Daily Telegraph, Sydney, Dec. 7, 2004).