Bactéria resistente a antibióticos há bilhões de anos 'falou e disse': não sou evidência a favor da evolução!
Posted: 14 Apr 2012 03:44 AM PDT
Key to New Antibiotics Could Be Deep Within Isolated Cave
ScienceDaily (Apr. 11, 2012) — Antibiotic-resistant bacteria found in one of the deepest, most isolated caves in the world could mean good news in the battle against superbugs. Researchers from McMaster and the University of Akron have discovered a remarkable prevalence of such bacteria in New Mexico's Lechuguilla Cave, a place isolated from human contact until very recently.
A researcher at 'Pearlsian Gulf'; calcite formations are in the background. (Credit: Copyright Max Wisshak).
The discovery that bacteria have developed defenses against antibiotics could indicate the presence of previously unknown, naturally occurring antibiotics that doctors could use to treat infections.
McMaster's Gerry Wright, scientific director of the Michael G. DeGroote Institute for Infectious Disease Research, and Hazel Barton, associate professor of biology at the University of Akron, collected strains of bacteria from the cave's deepest recesses.
None of the bacteria are capable of causing human disease, nor have they ever been exposed to human sources of antibiotics but they pair found that almost all were resistant to at least one antibiotic. Some were resistant to as many as 14 different antibiotics.
In all, resistance was found to virtually every antibiotic that doctors currently use to treat patients.
"Our study shows that antibiotic resistance is hard-wired into bacteria. It could be billions of years old, but we have only been trying to understand it for the last 70 years," said Wright. "This has important clinical implications. It suggests that there are far more antibiotics in the environment that could be found and used to treat currently untreatable infections."
The researchers also identified resistance in bacteria related to the bacterium that causes anthrax. This resistance has yet to emerge in the clinic.
Read more here/Leia mais aqui: Science Daily
Antibiotic Resistance Is Prevalent in an Isolated Cave Microbiome
Kirandeep Bhullar1, Nicholas Waglechner1, Andrew Pawlowski1, Kalinka Koteva1, Eric D. Banks2, Michael D. Johnston2, Hazel A. Barton2, Gerard D. Wright1*
1 M.G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada, 2 Department of Biology, University of Akron, Akron, Ohio, United States of America
Antibiotic resistance is a global challenge that impacts all pharmaceutically used antibiotics. The origin of the genes associated with this resistance is of significant importance to our understanding of the evolution and dissemination of antibiotic resistance in pathogens. A growing body of evidence implicates environmental organisms as reservoirs of these resistance genes; however, the role of anthropogenic use of antibiotics in the emergence of these genes is controversial. We report a screen of a sample of the culturable microbiome of Lechuguilla Cave, New Mexico, in a region of the cave that has been isolated for over 4 million years. We report that, like surface microbes, these bacteria were highly resistant to antibiotics; some strains were resistant to 14 different commercially available antibiotics. Resistance was detected to a wide range of structurally different antibiotics including daptomycin, an antibiotic of last resort in the treatment of drug resistant Gram-positive pathogens. Enzyme-mediated mechanisms of resistance were also discovered for natural and semi-synthetic macrolide antibiotics via glycosylation and through a kinase-mediated phosphorylation mechanism. Sequencing of the genome of one of the resistant bacteria identified a macrolide kinase encoding gene and characterization of its product revealed it to be related to a known family of kinases circulating in modern drug resistant pathogens. The implications of this study are significant to our understanding of the prevalence of resistance, even in microbiomes isolated from human use of antibiotics. This supports a growing understanding that antibiotic resistance is natural, ancient, and hard wired in the microbial pangenome.
Citation: Bhullar K, Waglechner N, Pawlowski 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
Editor: Ramy K. Aziz, Cairo University, Egypt
Received: December 13, 2011; Accepted: March 8, 2012; Published: April 11, 2012
Copyright: © 2012 Bhullar et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This research was supported by the Canada Research Chairs program (GDW), a Canadian Institutes of Health Research Operating Grant (MT-13536 to GDW), the National Science Foundation Microbial interactions and Processes Program (NSF0643462 to HAB) and a Canadian Institutes of Health Research Frederick Banting and Charles Best Canada Graduate Scholarship to KB. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: firstname.lastname@example.org
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NOTA DESTE BLOGGER:
Os autores de livros didáticos de Biologia aprovados pelo MEC/SEMTEC/PNLEM vão ter que remover mais uma "prova" a favor do fato, Fato, FATO da evolução.
Explico: Aos alunos é informado que a evolução é um fato porque as bactérias desenvolvem rapidamente resistência aos antibióticos. Aqui, esta resistência natural antecede há bilhões de anos nosso uso de antibióticos. O problema em continuar apresentando a resistência a antibióticos como evidência a favor da evolução, é que, neste caso, ela é "hard-wired in the microbial pangenome" (fisicamente conectada no pangenoma microbiano).
Está mais para uma explicação a la Design Inteligente do que mero acaso, fortuita necessidade, design não inteligente, oops do que para Darwin explicar.
E pensar que recentemente alguns cientistas da Academia Brasileira de Ciências, como Francisco Salzano e Sergio Pena, assinaram e enviaram uma carta ao seu presidente dizendo que a complexidade irredutível de sistemas biológicos - o flagelo bacteriano é um entre muitos, e a informação complexa especificada - o código digital do DNA, são conceitos sem fundamentação científica. Vide aqui a profunda ignorância científica expressa por esses luminares nesta missiva-folhetim tipo cala a boca!!!
Fui, nem sei por que, pensando que depois do flagelo bacteriano (A Caixa Preta de Darwin, Michael Behe), as bactérias estão cada vez mais revelando que nada em biologia faz sentido à luz da evolução.