Antibiotic resistance flourishes in freshwater systems

Apr 25, 2012

The author Dr. Seuss may have been on to something when he imagined that microscopic communities could live and flourish on small specs of dust, barely visible to the naked eye. In fact, such vibrant communities exist – in a material with a Seussical sounding, yet scientific name called 'floc'.

McMaster University researchers have now discovered that floc – "goo-like" substances that occur suspended in water and that host large communities of bacteria – also contain high levels of .

"This has important public health implications because the more antibiotic resistance there is, the less effective our antibiotic arsenal is against infectious diseases," said Lesley Warren, the principal investigator for the study that looked at floc in different freshwater systems.

The research was led by Warren, professor of earth sciences and Gerry Wright, scientific director of the Michael G. DeGroote Institute for Infectious Disease Research, both of McMaster, along with Ian Droppo, a research scientist at Environment Canada.

They examined floc collected from Hamilton Harbour, which is impacted by sewer overflow; Sunnyside Beach in Toronto, which is impacted by wastewater; a rural stream near Guelph, impacted by light agricultural activities; and a remote lake in a natural preserve area in Algonquin Park, accessible only by float plane.

Researchers analyzed the water and floc samples for trace element concentrations and the presence of 54 antibiotic resistant genes.

They were surprised to discover that genes encoding resistance to clinically relevant antibiotics were present in floc bacteria at all four sites, although resistance varied in intensity based on human influence. That is, there was less antibiotic resistance detectable from Algonquin Lake compared to Hamilton Harbour, which harbored the highest concentration of floc trace elements.

"What this tells us is that antibiotic resistance is widespread in aquatic environments ranging from heavily impacted urban sites to remote areas," said Warren. "Yet, it also demonstrates that areas with greater human impact are important reservoirs for clinically important antibiotic resistance.

Floc are vibrant microbial communities that attract contaminants such as trace metals that are markers of resistance, Wright said.

Warren added the study of antibiotic resistance in floc has never been done, "and we are only scratching the surface. The presence of environmental bacterial communities in aquatic environments represents a significant, largely unknown source of antibiotic resistance," she said. "The better we understand what is out there, the better we can develop policies to safeguard human health as best we can."

Explore further: How steroid hormones enable plants to grow

More information: The research has been published in the science journal Applied and Environmental Microbiology.

add to favorites email to friend print save as pdf

Related Stories

Researcher studies drug-resistant bacteria in environment

Mar 19, 2008

Water is essential to life, but the water we drink to stay alive could also be making us sick. Lesley Warren, associate professor in the School of Geography & Earth Sciences, is studying the interaction between ...

Newly discovered reservoir of antibiotic resistance genes

Oct 21, 2011

Waters polluted by the ordure of pigs, poultry, or cattle represent a reservoir of antibiotic resistance genes, both known and potentially novel. These resistance genes can be spread among different bacterial species by bacteriophage, ...

Resistance to antibiotics is ancient: study

Aug 31, 2011

Scientists were surprised at how fast bacteria developed resistance to the miracle antibiotic drugs when they were developed less than a century ago. Now scientists at McMaster University have found that resistance has been ...

Recommended for you

How steroid hormones enable plants to grow

14 hours ago

Plants can adapt extremely quickly to changes in their environment. Hormones, chemical messengers that are activated in direct response to light and temperature stimuli help them achieve this. Plant steroid ...

Surviving the attack of killer microbes

15 hours ago

The ability to find food and avoid predation dictates whether most organisms live to spread their genes to the next generation or die trying. But for some species of microbe, a unique virus changes the rules ...

Histones and the mystery of cell proliferation

16 hours ago

Before cells divide, they create so much genetic material that it must be wound onto spools before the two new cells can split apart. These spools are actually proteins called histones, and they must multiply ...

New discovery: Microbes create dripstones

Aug 18, 2014

According to new research humble, microscopic organisms can create dripstones in caves. This illustrates how biological life can influence the formation of Earth's geology - and the same may be happening ...

User comments : 0