Antibiotic-resistant bacteria are becoming airborne, and Texas cattle ranches could be the source of these potentially hazardous microorganisms.
Texas Tech University researchers examined particulate matter in the air, finding both antibiotics and antibiotic-resistant bacteria in samples taken downwind from cattle ranches. Investigators are worried that this material could be carried by wind into populated areas, hindering treatments for potentially dangerous diseases. Over 80 percent of all antibiotics sold in the United States are used in cattle to lengthen lives and improve yields.
The 10 ranches examined in the study were all located within 200 miles of the city of Lubbock, with samples being taken over a period of six months. The investigation focused on feedlots in the South Plains and Panhandle of Texas. Cattle at these facilities are exposed to large quantities of antibiotics as they are fattened up before they are brought to market.
"To our knowledge, this study is among the first to detect and quantify antibiotics and antibiotic-resistant genes ... associated with airborne PM emitted from beef cattle feed yards," environmental toxicology researchers at Texas Tech University said.
Each year, around 2 million Americans are infected by bacteria resistant to a wide range of treatments, and 23,000 die of the resulting diseases. Most fatalities from infections by antibiotic-resistant bacteria occur in health care settings, such as nursing homes and hospitals.
Researchers noted that the emergence of bacteria resistant to antibiotics is often correlated with the use of the drugs in commercial cattle stocks. In 2013, the Food and Drug Administration announced new guidelines aimed at reducing the use of antibiotics in cattle.
It has long been known that antibiotic-resistant bacteria can infect humans who come in contact with meat from the cattle provided with antibiotics, or with water from pens of the animals. This is the first time that DNA from the drugs and microbes have been detected in the air.
"If I truly thought that the usage of these products was putting anyone at danger, I wouldn't be using them," Sam Ives, a veterinarian from the Texas Cattle Feeders Association, said.
Samples were collected through the use of a specially designed vaccuum, located on a rural road.
Concentrations of the targeted materials were found to be 4,000 percent higher downwind from the feedlots compared with upwind locations.
"We believe that this bacteria could remain active for a long period of time and, given the wind that we have around Lubbock, it could be traveling for long distances," Phil Smith of Texas Tech University told the press.
Detection of genetic material from antiobiotics and bacteria resistance to the drugs was detailed in Environmental Health Perspectives.
Photo: Woody Hibbard | Flickr