Category Archives: Science

WHO lists drug-resitant bacteria fight priorities


Following up on our earlier post about the soaring rates of antibiotic-resistant bacteria in children comes word from the World Health Organization of a new catalog on the rising number of drug-repellent microbes, setting priorities for development of new medical treatments:

WHO today published its first ever list of antibiotic-resistant “priority pathogens” – a catalogue of 12 families of bacteria that pose the greatest threat to human health.

The list was drawn up in a bid to guide and promote research and development (R&D) of new antibiotics, as part of WHO’s efforts to address growing global resistance to antimicrobial medicines.

The list highlights in particular the threat of gram-negative bacteria that are resistant to multiple antibiotics. These bacteria have built-in abilities to find new ways to resist treatment and can pass along genetic material that allows other bacteria to become drug-resistant as well.

“This list is a new tool to ensure R&D responds to urgent public health needs,” says Dr Marie-Paule Kieny, WHO’s Assistant Director-General for Health Systems and Innovation. “Antibiotic resistance is growing, and we are fast running out of treatment options. If we leave it to market forces alone, the new antibiotics we most urgently need are not going to be developed in time.”

The WHO list is divided into three categories according to the urgency of need for new antibiotics: critical, high and medium priority.

The most critical group of all includes multidrug resistant bacteria that pose a particular threat in hospitals, nursing homes, and among patients whose care requires devices such as ventilators and blood catheters. They include Acinetobacter, Pseudomonas and various Enterobacteriaceae (including Klebsiella, E. coli, Serratia, and Proteus). They can cause severe and often deadly infections such as bloodstream infections and pneumonia.

These bacteria have become resistant to a large number of antibiotics, including carbapenems and third generation cephalosporins – the best available antibiotics for treating multi-drug resistant bacteria.

The second and third tiers in the list – the high and medium priority categories – contain other increasingly drug-resistant bacteria that cause more common diseases such as gonorrhoea and food poisoning caused by salmonella.

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Headline of the day: It’s the TrumpPhenomenon™


From Science:

Spinning black holes could fling off clouds of dark matter particles

Child antibiotic-resistant infections soar 700%


The Enterobacteriaceae are members a family of bacteria that don’t thrive in the open air, proliferating instead in water, soil, and the digestive tracts of larger animals. Like, say, us.

While many Enterobacteriaceae are helpful in digesting what we eat, others are much more nasty, including Salmonella, Escherichia coli, and Yersinia pestis [cause of the bubonic plague].

For most of the seven decades we’ve spent on planet Earth, a dose of penicillin or some of the other antibiotics developed since would provide a reliable cure,

But no longer, because overuse of antibiotics both in human medicine and in industrial animal agriculture and the failure of patients to take full courses of prescribed and unprescribed medications have given rise to bacteria capable of withstanding all those medications.

In just eight years, starting in 2007, the rate of antibiotic-resistant Enterobacteriaceae in U.S. children has soared a shocking 700 percent.

From Case Western University:

The adage that kids are growing up too fast these days has yet another locus of applicability.

In a new, first-of-its-kind study, researchers from Case Western Reserve University School of Medicine have found a 700-percent surge in infections caused by bacteria from the Enterobacteriaceae family resistant to multiple kinds of antibiotics among children in the US. These antibiotic resistant infections are in turn linked to longer hospital stays and potentially greater risk of death.

The research, published [an astounding $251 to read — esnl] in the March issue of the Journal of the Pediatric Infectious Diseases Society, is the first known effort to comprehensively examine the problem of multi-drug resistant infections among patients under 18 admitted to US children’s hospitals with Enterobacteriaceae infections. Earlier studies focused mainly on adults, while some looked at young people in more limited geographical areas, such as individual hospitals or cities, or used more limited surveillance data.

“There is a clear and alarming upswing throughout this country of antibiotic resistant Enterobacteriaceae infections in kids and teens,” said lead author Sharon B. Meropol, MD, PhD, a pediatrician and epidemiologist at Case Western Reserve University School of Medicine and Rainbow Babies and Children’s Hospital in Cleveland. “This makes it harder to effectively treat our patients’ infections. The problem is compounded because there are fewer antibiotics approved for young people than adults to begin with. Health care providers have to make sure we only prescribe antibiotics when they’re really needed. It’s also essential to stop using antibiotics in healthy agricultural animals.”

In the retrospective study, Meropol and co-authors Allison A. Haupt, MSPH, and Sara M. Debanne, PhD, both from Case Western Reserve University School of Medicine, analyzed medical data from nearly 94,000 patients under the age of 18 years diagnosed with Enterobacteriaceae-associated infections at 48 children’s hospitals throughout the US. The average age was 4.1 years. Enterobacteriaceae are a family of bacteria; some types are harmless, but they also include such pathogens as Salmonella and Escherichia coli; Enterobacteriaceae are responsible for a rising proportion of serious bacterial infections in children.

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Colorado River Basin faces epochal droughts


And they’ve already begun, according to The 21st century Colorado River hot drought and implications for the future [open access]. a new report from Scientists at the Colorado Water Institute and the university of Arizona, just published in Water Resources Research.

From the American Geophysical Union:

Warming in the 21st century reduced Colorado River flows by at least 0.5 million acre-feet, about the amount of water used by 2 million people for one year, according to new research.

The research is the first to quantify the different effects of temperature and precipitation on recent Colorado River flow, said authors Bradley Udall of Colorado State University and Jonathan Overpeck of the University of Arizona.

“This paper is the first to show the large role that warming temperatures are playing in reducing the flows of the Colorado River,” said Overpeck, UA Regents’ Professor of Geosciences and of Hydrology and Atmospheric Sciences and director of the UA Institute of the Environment. The new paper has been accepted for publication in Water Resources Research, a journal of the American Geophysical Union.

From 2000-2014, the river’s flows declined to only 81 percent of the 20th-century average, a reduction of about 2.9 million acre-feet of water per year. One acre-foot of water will serve a family of four for one year, according to the U.S. Bureau of Reclamation.

From one-sixth to one-half of the 21st-century reduction in flow can be attributed to the higher temperatures since 2000, report Udall and Overpeck. Their analysis shows as temperature continues to increase with climate change, Colorado River flows will continue to decline.

Current climate change models indicate temperatures will increase as long as humans continue to emit greenhouse gases into the atmosphere, but the projections of future precipitation are far less certain.

Forty million people rely on the Colorado River for water, according to the U.S. Bureau of Reclamation. The river supplies water to seven U.S. Western states plus the Mexican states of Sonora and Baja California.

Udall, a senior water and climate scientist/scholar at CSU’s Colorado Water Institute, said, “The future of Colorado River is far less rosy than other recent assessments have portrayed. A clear message to water managers is that they need to plan for significantly lower river flows.”

The study’s findings, he said, “provide a sobering look at future Colorado River flows.”

The Colorado River Basin has been in a drought since 2000. Previous research has shown the region’s risk of a megadrought – one lasting more than 20 years – rises as temperatures increase.

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Catastrophe imminent for the world’s oceans


The lead author of a comprehensive new survey of the world’s oceans offers of offers a stark summation of his findings: “The rate of change underway in our oceans is faster than at any point we know of in geological history.”

What is at stake is nothing less than the entire ecosystem covering 71 percent of the planet’s surface, the foundation on which all life on earth is based.

From Heriot-Watt University in Edinburgh:

New research from Heriot-Watt, published on open-access journal Elementa today, shows that food supply to some areas of the Earth’s deep oceans will decline by up to half by 2100.

Dr Andrew Sweetman, associate professor at the Lyell Centre for Earth and Marine Science, and colleagues from 20 of the world’s leading oceanographic research centres have used earth system models and projected climate change scenarios, developed for the Intergovernmental Panel on Climate Change (IPCC), to quantify impending changes to deep oceans.

The team looked at a number of sea and ocean beds, from the Arctic to Antarctic Oceans, focusing on bathyal (200-3000m) and abyssal (3000-6000m) depths. As well as measuring how the deep oceans’ food sources will decline, the team examined the impact that increased seabed temperatures, declining oxygen levels and increasingly acidic seawater will have, under the sea and across the planet.

Sweetman, associate professor at Heriot-Watt’s Lyell Centre for Earth and Marine Science and Technology, said: “The rate of change underway in our oceans is faster than at any point we know of in geological history.

“Deep seafloor ecosystems provide services that are vitally important to the entire ocean and biosphere; we should all be concerned at what’s happening on our ocean floors.”

Most of the deep sea currently experiences a severe lack of food, but according to Dr Sweetman and his research team, it is about to face a famine.

Sweetman continued: “Abyssal ocean environments, which are over 3000m deep, are some of the most food-deprived regions on the planet.

“These habitats currently rely on less carbon per m2 each year than is present in a single sugar cube.

“We’ve shown that large areas of the abyss will have this tiny amount of food halved by 2100. For a habitat that covers half the earth, the impacts of this will be enormous.”

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Map of the day: Antarctic sea ice hits a new low


We begin with two images from the National Snow and Ice Data Center.

First, the extent of Antarctic sea ice as of 20 February 2017, with the yellow line indicating the average sea ice coverage in recent years:

blog-ice-map

Second, a graph showing the progression of coverage in the 2016-2017 cycle [blue line] compared to other years:

blog-ice-chartWhat make this summer’s record low even more remarkable is that it immediately follows years of record highs. And we say summer because that’s the current season in the Southern Hemisphere.

More from MercoPress:

This year the extent of summer sea ice in the Antarctic is the lowest on record. The Antarctic sea ice minimum marks the day – typically towards end of February – when sea ice reaches its smallest extent at the end of the summer melt season, before expanding again as the winter sets in. This year, sea ice extent contracted to 2.28m sq km on 13 February, according to data from the US National Snow and Ice Data Center (NSIDC).

The extent is a fraction smaller than a previous low of 884,173 sq miles recorded on 27 February 1997 in satellite records dating back to 1979. Scientists, including those at British Antarctic Survey, are monitoring the data closely and trying to understand why this year is presenting a minimum.

BAS climate scientist Dr James Pope says: “At this time, so close to minimum event, it is difficult to identify what is causing the record minimum and whether anything significant has changed. Sea ice is highly variable on year-to-year time-scales and therefore the recent record maximum extent from a couple of years ago and this year’s record minimum could both be the result of short- term changes rather than longer-term trends.

“What’s interesting is that Antarctic sea ice has been steadily increasing in size, year on year from the 1970s. So what’s happening now is against the trend. And whilst it’s significant, we won’t know for a couple of years whether this is a single event or a switch away from the previously observed increase. We will now study the data with interest and look at what is causing this minimum.”

Record El Niño devastates Pacific Coast beaches


Following up on the previous post, a look at another aspect of climate change.

Record waves generated by El Niño have devastated beaches all along the Pacific coast, and as a new study [open access] concludes, “climate change projections suggest a possible increase in the frequency of extreme El Niño and La Niña events,” meaning this year’s disaster could be just the beginning of worse to come.

More from the U.S. Geological Survey:

In a new study, U.S. Geological Survey scientists and their colleagues document how the 2015-16 winter featured one of the most powerful El Niño climate events of the last 145 years.

Investigating 29 beaches along the U.S West Coast from Washington to southern California, researchers found that winter beach erosion was 76 percent above normal, by far the highest ever recorded, and most beaches in California eroded beyond historical extremes. If severe El Niño events such as this one become more common in the future as studies suggest, this coastal region, home to more than 25 million people, will become increasingly vulnerable to coastal hazards, independently of projected sea level rise.

The authors assessed seasonal changes on 29 beaches along approximately 2000 kilometers (1243 miles) of the U.S. West Coast. Surveying the beaches included making 3-D surface maps and cross-shore profiles using aerial lidar (light detection and ranging), GPS topographic surveys, and direct measurements of sand levels, combined with wave and water level data at each beach, collectively spanning 1997-2016. Winter beach erosion or the removal and loss of sand from the beach is a normal seasonal process, but the extent of erosion can be more severe during El Niño events than in other years.

“Wave conditions and coastal response were unprecedented for many locations during the winter of 2015-16. The winter wave energy equaled or exceeded measured historical maximums along the U.S. West Coast, corresponding to extreme beach erosion across the region,” said USGS geologist and lead author of the report, Patrick Barnard.

The 2015-16 El Niño was one of the three strongest events ever recorded, along with El Niño winters of 1982-83 and 1997-98. While most beaches in California eroded beyond historical extremes, some beaches fared better. “The condition of the beach before the winter of 2015 strongly influenced the severity of erosion and the ability of the beach to recover afterward through natural replenishment processes,” said UC Santa Barbara marine ecologist and co-author David Hubbard.

Rivers still supply the primary source of sand to California beaches, despite long-term reductions in the 20th century due to extensive dam construction. But as California is in the midst of a major drought, the resulting lower river flows equated to even less sand being carried to the coast to help sustain beaches.

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