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Friday, 28 April 2017

Rare Microbes Make a Critical Contribution to the Environment

New work published in Applied and Environmental Microbiology suggests that bacteria present at very small levels in the environment actually make a vital contribution to the health and stability of that environment. This research concerns microbes that don’t usually account for more than a tenth of a percent of the bacteria in the whole population. "The work aims to provide a fundamental understanding of how biodiversity contributes to ecosystem functioning," said the corresponding author of the work, Kostas Konstantinidis, PhD.

In the environment at large, these are low levels, but in individual communities there may be hundreds of them, actually therefore, composing 20 to 30 percent of specific bacteria in an aquatic group. Termed the rare biosphere, these uncommon species were found to harbor large amounts of genes capable of allowing for organic pollutant degredation. The abilities conferred by those microbes may be helping the entire microbial population remain stable in the face of environmental pressures and alterations. The investigators, a team from Georgia Institute of Technology, Atlanta, wanted to test this idea, so they created mesocosms, or laboratory environments, made up of 20 liters of water. These reservoirs were then inoculated with water samples taken from a local freshwater source, Lake Lanier. 

                                                     (c) Google Image
Three common organic chemicals, not present in the samples they took from the lake, were then dribbled into the mesocosms. The scientists wanted ot ensure that the microbes had not be acclimated to the presence of those pollutants in order to reveal as much as possible about the microbes’ abilities. "Also, the important environmental pollutants are generally at low concentration in most natural environments, similar to the organic compounds used here--except during major events such as oil spills" said Konstantinidis, the Carlton S. Wilder Associate Professor in the School of Civil & Environmental Engineering at Georgia Tech.

The pollutants used included 2,4-dichlorophenoxyacetic acid (2,4-D), a common herbicide that is a known endocrine disrupter and may be a carcinogen, according to the International Agency for Research on Cancer. The other compounds were caffeine (1,3,7-trimethyluric acid) and 4-nitrophenol (4-NP), used in fungicide production and one byproduct of pesticide breakdown.
"We chose these compounds because their biodegradation pathways and the underlying genes are known, which facilitated tracking which microbial populations encoded the proteins for the biodegradation of these organic compounds," explained Konstantinidis.

The researchers repeatedly assayed the bacterial levels in the mseocosms to find which ones grew more or grew less. "The results allowed us to rigorously test the hypothesis that low abundance species, as opposed to common species, provided the metabolic diversity that enabled the community to respond to the added compounds and the changing conditions," said Konstantinidis. The goal of the work was to improve our predictions of how microbial communities might react to future disruptions from stuff like oil, pesticides, or climate change, said Konstantinidis. We may learn a lot more about how microbes contribute to the function and resilience of our ecosystem, and the possible consequences microbes face due to contaminant spills or climate change.

Sources: AAAS/Eurekalert! Via American Society for Microbiology, Applied and Environmental Microbiology 

WHO Alerts the Globe to the 12 Deadliest Microbes.

Alarm bells have been ringing all over the world about drug-resistant superbugs, which are expected to pose a huge threat to human health in the coming decades. Years of overuse, misuse, and poor prescribing and purchasing habits has created a serious problem whereby humanity can no longer rely on the old standards that have been used to effectively treat bacterial infections for decades. The United Nations has identified the threat, now the World Health |Organization has produced a list of twelve microbes that are seen as major priorities for antibiotic development.

The WHO aims to promote research and development by publishing this list, and they have categorized the bacteria by how urgent the threat has been perceived to be - critical, high, and medium priority. The biggest problem is seen as the one that affects people already dealing with health issues - those infections that are primarily found in hospital, clinic and nursing home settings. In this group are Acinetobacter, Pseudomonas and the family of Enterobacteriaceae which includes Klebsiella, Proteus and the commonly known E. coli. Those bacteria often cause pneumonia and infections of the blood. Bacteria that have become resistant to virtually all antibiotic treatments are in this group. Carbapenems are seen as a last-resort treatment for various bacterial infections that are impervious to typical treatments, and some bacterial strains have gained resistance to those drugs (usually by gaining a piece of genetic material). The next categories include bacteria that are still very dangerous, resulting in illnesses like gonorrhoea and food-borne illness.

"This list is a new tool to ensure R&D responds to urgent public health needs," explained 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." There is global attention on this problem, which is planned to be discussed at a meeting of health experts in Berlin. "We need effective antibiotics for our health systems. We have to take joint action today for a healthier tomorrow. Therefore, we will discuss and bring the attention of the G20 to the fight against antimicrobial resistance. WHO’s first global priority pathogen list is an important new tool to secure and guide research and development related to new antibiotics," commented Mr Hermann Gröhe, the Federal Minister of Health.

The list was created by scientists at the Division of Infectious Diseases at the University of Tubingen, Germany, considering characteristics like how deadly resulting infections are, how treatable they are, how easily they spread, how preventable they are, etc. The list was then reviewed by international experts.
"New antibiotics targeting this priority list of pathogens will help to reduce deaths due to resistant infections around the world," said one researchers that helped to curate the list, Professor Evelina Tacconelli, who is Head of the Division of Infectious Diseases at the University of Tübingen. "Waiting any longer will cause further public health problems and dramatically impact on patient care."

Source WHO

Fight against Killer Superbugs

Last September, the United Nations gathered to recognize the serious threat that antibiotic resistance poses to the public. It is estimated that antibiotic resistance is responsible for the deaths of over 700,000 people worldwide annually. Only a few days ago, the World Health Organization released a list of the microbial pathogens that pose the biggest threat to human health. Needless to say, any progress in this fight is a benefit to people. Researchers have some good news in the face of all the warnings; it appears that a drug combination is effective against two of the three pathogenic bacteria identified by WHO as well as another dangerous pathogen, all of which are gram negative bacteria. These findings have been reported in Nature Microbiology.

Gram-negative bacteria have a impervious outer shell that serves as a shield against many commonly used, and usually effective bacteria. That makes for an especially tough bug, causing many deaths, especially in hospital settings.
"These pathogens are really hard nuts to crack, but we found a molecule that shreds that shell and allows antibiotics to enter and be effective," explained the senior author of the report, Eric Brown, a Professor of Biochemistry and Biomedical Science at McMaster's Michael G. DeGroote School of Medicine and a scientist of the Michael G: deGroote Institute for Infectious Disease Research.

                                               (c) Google Image
The researchers determined that an antiprotozoal drug called pentamidine breaks into the surface of even the most resistant Gram-negative bacteria. When this antifungal drug was used in combination with antibiotics, it was effective against multi drug resistant antibiotics. "These pathogens are really hard nuts to crack, but we found a molecule that shreds that shell and allows antibiotics to enter and be effective," said Brown.

When pentamidine was used with antibiotics it could combat enterobacteriaceae and Acinetobacter baumannii, two drugs on the list released by WHO. This combination of drugs was also effective against another dangerous pathogen, Pseudomonas aeruginosa. These results were modeled in rodents and in the lab, and now testing will have to investigate the side effects and safety for use in humans. Brown's lab continues to search for more therapies. "One of the things we want to pursue further is why this is working so well," he concluded.

Culled from LabRoots Inc. 

Saturday, 15 April 2017

Video: Microbial Life may sustain in Enceladus environment

Comparing the size of Enceladus (Image: Futurism)
Enceladus is a small moon of Saturn, which is just 502 km in diameter may sustain microbial life according to a recent research published in the journal Science. Cassini spacecraft able to manage to find the icy plumes contain molecular hydrogen. It has the chemistry, energy and atmosphere that can help to sustain microbial life. The question now lies to find whether it is true now.

Video Courtesy: NASA Jet Propulsion Laboratory


Tuesday, 11 April 2017

Pets exposure can reduce Babies risk of Allergies or Obesity

A new Canadian research investigation proved that owing dog or cat may benefit children to gain early immunity to allergies or obesity. The research was led by University of Alberta scientists shown that two important microbes transferred through pets are important contenders to reduce the risk of obesity or allergies.

Anita Kozyrskyj, a pediatric epidemiologist at University of Alberta said, “There’s definitely a critical window of time when gut immunity and microbes co-develop, and when disruptions to the process result in changes to gut immunity”.

Team collected fecal samples of 746 infants, where two bacteria Ruminococcus and Oscillospira were abundant who are exposed to pets (70% were dogs). These two bacteria are known to associate with lower risk of allergies or obesity among children.

Althogh researchers aren’t sure about the exposure was the direct contact with animal fur or indirect contact through humans but pet exposure has been the important factor to affect the gut microbiome indirectly. Pet exposure to pregnant mothers also can be factor for gut immunity for unborn baby.

“It’s not far-fetched that the pharmaceutical industry will try to create a supplement of these microbiomes, much like was done with probiotics,” Kozyrskyj said.

The research was funded by the Canadian Institutes of Health Research and the Allergy, Genes and Environment Network (AllerGen NCE).

Journal Source: Microbiome

Sunday, 2 April 2017

80 Million years old Microbes identified from Bees' Gut

80 Million years is a very long time since bees began exhibiting their own social behaviour and they carry over generations of such old bacteria till today inside host bees. A new study published in the journal Science Advances led by researchers from University of Texas identifies such group of bacteria that live in guts of bees and have 80 million years of generation after generation journey. The importance of this finding lies how the social creatures like humans and bees have distinctive relationship with such tiny creatures called bacteria evolving together over such long period of time.

“The fact that these bacteria have been with the bees for so long says that they are a key part of the biology of social bees,” says Nancy Moran, a professor of integrative biology at the university who co-led the research with postdoctoral researcher Waldan Kwong. “And it suggests that disrupting the microbiome, through antibiotics or other kinds of stress, could cause health problems.”

Bees may have acquired their core microbiota around the same time as the transition to social lifestyles. Closely related bees have more similar microbiomes, suggesting co-diversification of host bees and their microbes. Image: Waldan K. Kwong and John. S. Ascher, University of Texas

Different bees have different social life style and they adopt different microbiome in their gut accordingly. In this new research, they identified five species of bacteria that bees took up 80million years ago. Those bacteria able to survive and evolved inside the gut in diversifying way and are specific to different species of bees.

“Most of them can’t live under atmospheric oxygen levels,” says Moran. “They can’t just grow in nectar or on the surface of a plant. They have to be in the bee gut.”

This is also the first time study where they chart the evolution of gut bacteria into animal host. Until now this is the longest evolution of gut bacteria.

A postdoctoral researcher from University of British Columbia, Kwong travelled across Asia to collect bees for such an important project. He has isolated 27 different bees species and sequenced DNA to identify different classes of gut microbiome. For each species they identified they built set of phylogeny or evolution tree. The final result was co-specification, where hundreds of species that are alive today have unique strains of bacterial species shared.

Scientists suggest that these bacteria are typically a symbiont where they can sustain only at guts of certain bees.


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