Emergence of Antibiotic-Resistant Bacteria in the U.S.

For the first time, an individual in the U.S. has been infected with a bacterium that is resistant to existing antibiotics. According to the Associated Press, U.S. health officials are concerned that this resistance may transfer to other bacteria, leading to the emergence of 'superbugs' resistant to all known antibiotics. Dr. Tom Frieden, director of the Centers for Disease Control and Prevention, states, 'If we do not act immediately, this will be the end of antibiotics.' Similar cases have occurred in other countries, but this is the first reported case in the U.S. This 49-year-old woman visited a military clinic in Pennsylvania last month to treat a urinary tract infection. Initial tests indicated an infection caused by the bacterium 'Escherichia coli' (E. coli). However, further tests showed that this bacterium was resistant to the antibiotics typically prescribed for such infections. The woman was treated with a different type of antibiotic. Although she appeared to have recovered, subsequent tests confirmed that the 'Escherichia coli' carried a gene that conferred resistance to the antibiotic 'colistin.' Colistin is an old antibiotic that, since the 1970s, has often been avoided by doctors due to severe side effects. However, with the ineffectiveness of other antibiotics, colistin has regained use. It is used to treat severe infections that are resistant to the last line of antibiotics known as 'carbapenems.' If this bacterium carries the colistin-resistant gene, doctors may have no other treatment options. The CDC is investigating how this bacterium was transmitted to the woman. Officials state that she has not traveled abroad recently. Colistin-resistant bacteria have been observed among animals and humans in China, Europe, and Canada. According to officials, colistin-resistant E. coli has also been seen in a pig in the U.S., but there is no connection to the case in Pennsylvania.