Fowl food spreads resistance, after many years of feeding chickens, cattle, pigs and other animals growth supplements that contain antibiotics, according to an article in New Scientist, 10 Apr 2004. “Feed grade” antibiotics are not the highly purified chemicals used in medicine, but crude preparations that contain bacterial fragments, including intact pieces of DNA. Karen Lu and colleagues have studied avoparcin, a feed supplement antibiotic, and found it contained intact copies of a cluster of three antibiotic resistance genes similar to those that confer resistance to Vancomycin, a medical antibiotic used as a last resort in treating multi-resistant “superbugs”. Recent research, described in Nature Reviews Microbiology, Mar 2004 has shown that bacteria can engulf pieces of other bacterial DNA and incorporate any intact genes into their own DNA. This provides another means of acquiring antibiotic resistance for bacteria in the intestines of intensively farmed birds and animals and adds to the overall level of resistant bacteria in the environment.

Editorial Comment: These studies confirm our often repeated statement that the rise of antibiotic resistance in bacteria over the past few decades is not caused by evolving new genes, but by redistribution of already existing genes which were the result of a well planned creation which was intended to survive. (Ref. antibiotic resistance, farming, bacteria)