Antibiotic resistance found in remote South American tribe
Scientists from the U.S. and Venezuela have discovered antibiotic resistant genes in the bacteria of the members of a South American tribe that has had no contact with the industrialized world or exposure to antibiotic drugs.That suggests that antibiotic resistant genes can occur naturally in the human body and may not be solely a response to exposure to antibiotics.
Current thinking is that antibiotic resistance has stemmed from inappropriate overuse of antibiotics in medicine and agriculture. However, this new study of the Yanomami Amerindians, tribe that has lived away from civilization in the mountains of southern Venezuela for thousands of years, provides evidence that resistance genes have been in the human microbiome long before the invention of modern antibiotics.
To conduct their study, the team exposed bacteria from members of the tribe to 23 different antibiotics and found the drugs were able to kill all of them. But when they ran further tests, the researchers found the bacteria contained "silent" resistance genes that were activated by exposure to the antibiotics. The results showed cultured bacteria from the tribe members contained many resistance genes that can fight off many modern antibiotics.
The team offered a possible explanation for this finding, a concept known as "cross-resistance." This is where genes that help bacteria resist natural antibiotics can also help them resist related synthetic drugs.