Reader Comments
Post a new comment on this article
Post Your Discussion Comment
Please follow our guidelines for comments and review our competing interests policy. Comments that do not conform to our guidelines will be promptly removed and the user account disabled. The following must be avoided:
- Remarks that could be interpreted as allegations of misconduct
- Unsupported assertions or statements
- Inflammatory or insulting language
Thank You!
Thank you for taking the time to flag this posting; we review flagged postings on a regular basis.
closeStudies of Pre-antibiotic Communities
Posted by chdavis on 31 Jul 2012 at 17:25 GMT
Gerard Wright and colleagues have documented the presence of antibiotic resistance in the microbiome of a cave that has been isolated for more than 4 million years and used elegant methods to show that the mechanisms of resistance include enzymes circulating in modern drug-resistant pathogens [1]. This work confirms and extends Wright’s previous remarkable study of a collection of antibiotic resistance genes from 30,000 year-old permafrost sediments [2].
I thank the authors for finding and referencing our 1970 article reporting the detection of transferable antibiotic resistance plasmids in the fecal flora of an antibiotic virgin population living in a remote area of Borneo [3]. Like the current authors, we concluded that antibiotic resistance was a natural phenomenon that predated human use of antibiotics. I differ, however, with the authors’ interpretation of our data. They reference our article as evidence that plasmids from bacterial collections that predate the antibiotic era are largely devoid of resistance elements. While it is true that we detected resistance plasmids from only 6 strains of Escherichia coli isolated from 128 individuals, our observation clearly documents their presence in a pre-antibiotic community of human beings.
The presence of antibiotic resistance genes in pre-antibiotic communities suggests that their presence provides ecological advantages to bacteria independently of anthropogenic use of antibiotics. The presence of resistance genes in ancient bacteria, however, should only serve as a further caution against the indiscriminate use of antimicrobial compounds. The genetic elements have been present for millions of years and just waiting for further selective pressure.
1. Bhullar K, Waglechner N, Pawloski A, Koteva K, Banks ED, et al. (2012) Antibiotic Resistance is Prevalent in an Isolated Cave Microbiome. PLoS ONE 7(4): e34953. doi:10.1371/journal.pone.0034953.
2. D’Costa VM, King CE, Kalan L, Morar M, Wilson WLSung, et al.(2011) Antibiotic Resistance Is Ancient. Nature 477 (7365): 457-61. doi: 10.1038/nature10388.
3. Davis CE, Anandan J (1970) The evolution of r factor. A study of a “preantibiotic” community in Borneo. N Engl J Med 282: 117-122.