Pollution linked to antibiotic resistance

Date:
August 13, 2020
Source:
University of Georgia
Summary:
Antibiotic resistance is an increasing health problem, but
new research suggests it is not only caused by the overuse of
antibiotics. It's also caused by pollution.



FULL STORY ========================================================================== Antibiotic resistance is an increasing health problem, but new research suggests it is not only caused by the overuse of antibiotics. It's also
caused by pollution.


========================================================================== Using a process known as genomic analysis, University of Georgia
scientists found a strong correlation between antibiotic resistance and
heavy metal contamination in an environment.

Jesse C. Thomas IV, an alumnus of the College of Public Health and
the Savannah River Ecology Laboratory, found commonalities in soils contaminated with heavy metals on the U.S. Department of Energy's Savannah River Site near Aiken, South Carolina.

According to the study, published in the July issue of the journal
Microbial Biotechnology, soils with heavy metals had a higher level of
specific bacterial hosts that were accompanied by antibiotic-resistant
genes.

Hosts included Acidobacteriaoceae, Bradyrhizobium and Streptomyces. The bacteria had antibiotic-resistant genes, known as ARGs, for vancomycin, bacitracin and polymyxin. All three drugs are used to treat infections
in humans.

The bacteria also had an ARG for multidrug resistance, a strong defense
gene that can resist heavy metals as well as antibiotics, according to
Thomas, who was conducting his doctoral research at the time.



==========================================================================
When these ARGs were present in the soil, metal-resistant genes,
or MRGs, were present for several metals including arsenic, copper,
cadmium and zinc.

Thomas, currently a biologist at the Centers for Disease Control and Prevention, said microorganisms develop new strategies and countermeasures
over time to protect themselves.

"The overuse of antibiotics in the environment adds additional selection pressure on microorganisms that accelerates their ability to resist
multiple classes of antibiotics. But antibiotics aren't the only source
of selection pressure," Thomas said. "Many bacteria possess genes that simultaneously work on multiple compounds that would be toxic to the
cell, and this includes metals." Travis Glenn, professor in the public
health college, advised Thomas during the study. He said more research
needs to be done to determine if metal-resistant genes respond in the
same way to bacteria as antibiotic-resistant genes.

Unlike antibiotics, heavy metals don't degrade in the environment so
"they can exert long-standing pressure," according to Glenn, who also
directs the Institute of Bioinformatics.



==========================================================================
The study reports previous research identified antibiotic-resistance in
heavy metal-contaminated streams on the site by examining water samples
in the lab.

"When you expose the sample to a drug on a petri dish or assay, it only represents a fraction. This doesn't give you a complete picture. With
genomic analysis we were able to get much further," Thomas said.

The significance of the research is they can start to characterize
bacterial communities and specific ARG and MRG genes in the environment,
Glenn said.

It is clear that there are several human pathogens that develop antibiotic resistance -- overuse is not the only cause, according to Thomas. Human activities like agriculture and the combustion of fossil fuels play
a role.

"We need a better understanding of how bacteria are evolving over time,"
he said. "This can impact our drinking water and our food and eventually
our health."

========================================================================== Story Source: Materials provided by University_of_Georgia. Original
written by Vicky L.

Sutton-Jackson. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Jesse C. Thomas, Adelumola Oladeinde, Troy J. Kieran, John
W. Finger,
Natalia J. Bayona‐Va'squez, John C. Cartee, James C. Beasley,
John C. Seaman, J Vuan McArthur, Olin E. Rhodes, Travis C. Glenn.

Co‐occurrence of antibiotic, biocide, and heavy metal
resistance genes in bacteria from metal and radionuclide
contaminated soils at the Savannah River Site. Microbial
Biotechnology, 2020; 13 (4): 1179 DOI: 10.1111/1751-7915.13578 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200813142402.htm

--- up 4 weeks, 1 day, 1 hour, 55 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1337:3/111)