Bacteria Communicate by Touch, New Research Suggests

                                           Science Daily  — What if bacteria could talk to each other? What if they had a sense of touch? A new study by researchers at UC Santa Barbara suggests both, and theorizes that such cells may, in fact, need to communicate in order to perform certain functions.

The findings appeared recently in the journal Genes & Development.

Christopher Hayes, UCSB associate professor of molecular, cellular, and development biology, teamed with graduate students Elie Diner, Christina Beck, and Julia Webb to study uropathogenic E. coli (UPEC), which causes urinary tract infections in humans. They discovered a sibling-like link between cell systems that have largely been thought of as rivals.

The paper shows that bacteria expressing a contact--dependent growth inhibition system (CDI) can inhibit bacteria without such a system only if the target bacteria have CysK, a metabolic enzyme required for synthesis of the amino acid cysteine. CysK is shown to bind to the CDI toxin -- an enzyme that breaks RNA ó and activate it.

For a cell system typically thought of as existing only to kill other bacteria -- as CDIs have largely been -- the results are surprising, said Hayes, because they suggest that a CDI+ inhibitor cell has to get permission from its target in order to do the job.

"This is basically the inhibitor cell asking the target cell, 'Can I please inhibit you?'" he explained. "It makes no sense. Why add an extra layer of complexity? Why add a permissive factor? That's an unusual finding.

"We think now that the [CDI] system is not made solely because these cells want to go out and kill other cells," Hayes continued. "Our results suggest the possibility that these cells may use CDI to communicate as siblings and team up to work together; for example, in formation of a biofilm, which lends bacteria greater strength and better odds of survival."

The study points to the enzyme CysK as the potential catalyst to such bacterial communication -- like a secret handshake, or a password. In simpler terms, said Hayes, "If you have the right credentials, you're allowed into the club; otherwise you're turned away. There's a velvet rope, if you will, and if you're not one of the cool kids, you can't get in."

Although only UPEC was studied for this paper, Hayes said that the findings hold potential implications for pathogens from bacterial meningitis to the plague, as well as for plant-based bacteria that can devastate vegetation.

David Low, a UCSB professor of molecular, cellular, and developmental biology and secondary author on the paper, described the work by Hayes's laboratory as potentially groundbreaking for its insights into how bacteria communicate -- and the practical applications that could someday result.

"We are just starting to get some clues that bacteria may be talking to each other with a contact-dependent language," said Low. "They touch and respond to one another in different ways depending on the CDI systems and other genotypic factors. Our hope is that ultimately this work may aid the development of drugs that block or enhance touch-dependent communication, whether the bacteria is harmful or helpful."

The work was supported by grants from the National Institutes of Health and the National Science Foundation.

How warfarin becomes a danger

MONASH UNIVERSITY

The risk of severe side effects associated with a common blood-thinning medication is related to elderly patients misunderstanding medical instructions, according to new research. A team of researchers at Monash University studied the effects of warfarin. This drug has been used clinically for over 50 years for the prevention of blood clots in the elderly, but it also puts its patients at an increased risk of bleeding. The NHMRC-funded research, led by PhD scholar Basia Diug, found that psychosocial factors such as poor health literacy, depressed mood and impaired cognition were just as likely to cause an increased risk of bleeding as other factors, such as a patient's age. "Warfarin is an effective drug for treatment and prophylaxis of thromboembolic disorders, but despite routine monitoring, patients taking warfarin are at risk of haemorrhage," Ms Diug said. "Most conditions requiring warfarin manifest in older patients, the fastest growing group in our community, and require long-term care. "Despite the known risks, warfarin usage in Australia has been steadily increasing at a rate of nine per cent annually, and it remains one of the leading causes of harmful medication errors and medication-related adverse events." The study recommended that doctors consider the social circumstances of patients when prescribing warfarin, as the presence of multiple psychosocial deficits increased the risk of bleeding. Ms Diug's research was supervised by Professor John McNeil, Department of Epidemiology and Preventive Medicine, and conducted over two stages, involving over 500 patients recruited through Melbourne Pathology. The results were published in the international journal Stroke and the Medical Journal of Australia. The project was a collaboration between the Monash Faculty of Medicine, Nursing and Health Sciences, Faculty of Pharmacy and Pharmaceutical Sciences and experts from The Alfred Hospital and Melbourne Pathology. Director of Pharmacy at Alfred Health and Professor of Clinical Pharmacy at the Monash University Centre for Medicine Use and Safety (CMUS), Professor Michael Dooley, collaborated with Ms Diug on the project. "This work demonstrates the collaboration between clinicians and researchers across faculty lines that are a key component of the strength of having conjoint positions between the acute health care sector and academia," Professor Dooley said. Editor's Note: Original news release can be found here.

Why we should break up sitting times

BAKER IDI HEART & DIABETES INSTITUTE

Overweight office workers, drivers and call centre staff who sit for long periods could improve their health by simply breaking up their sitting time with frequent activity breaks according to new research by Baker IDI Heart and Diabetes Institute, published online today in Diabetes Care – a publication of the American Diabetes Association. Baker IDI researchers examined spikes in participants’ blood glucose levels after consuming a high-calorie meal and found that their bodies were much more effective in controlling glucose and insulin levels when they performed regular two minute bouts of either light or moderate-intensity activity. Repeated spikes in glucose, or blood sugar, are known to contribute to a number of negative health outcomes, including hardening of the arteries and cardiovascular disease. Insulin is important, because it plays a key role in controlling blood sugar levels. Lead researcher, Associate Professor David Dunstan explained; “When we eat, we get rises in blood glucose. With larger and more frequent rises in blood glucose, we gradually accumulate damage to the walls of our veins and arteries. This increases our susceptibility to heart disease. So, we want to minimise these rises in order to improve our health outcomes.” “In a controlled laboratory environment that mimicked the typical patterns of desk-bound office workers, participants who interrupted their sitting time with regular activity breaks, showed up to 30 per cent improvement in the body’s response to a meal containing glucose. The good news is that the improvements were seen even with light-intensity activity, which is the equivalent of strolling.” “Our research has already shown that sitting for long periods can be hazardous to health. Sedentary behaviour is also a risk factor for chronic diseases, including some cancers. The results of this study now provide some direction about what activity can be undertaken to break up sitting time and counteract the negative effects of sitting for long periods, including the frequency of breaks required to improve health outcomes. “Being overweight has been shown to be associated with an increased susceptibility to impaired glucose metabolism.  So the findings are likely to have important implications for people who already have difficulty processing blood sugars.” Dunstan said; “When we sit, we have muscle ‘dis-use’ – our muscles are essentially ‘sleeping’. When we’re up and moving, we’re contracting muscles and it appears that these frequent contractions throughout the day are beneficial for helping to regulate the body’s metabolic processes.” The findings may also provide added support to the current Australian OHS recommendations that desk bound employees take a break from their computer screen approximately every 30 minutes to reduce eye strain. While the majority of people in a modern office based environment are required by their jobs to sit for long periods, the researchers warned that there are other settings in which people need to be mindful of breaking up long sitting periods. These include the home environment where long periods of TV or video viewing and computer use is increasingly frequent or long car commutes that many people find difficult to avoid. “The findings are not confined to people who are overweight and suggest that even people who are not overweight could benefit from breaking up their sitting time, commented Dunstan.” Study Methodology Participants were aged 45-65 and were either overweight or obese with a body mass index of 31.2 kg/m2 (overweight or obese). Each participant was required to participate in three separate daily sitting schedules with a break of six days between each of the days. In the first trial condition, each participant sat for 5 hours with no break. In the second experiment, they walked on a treadmill at a light-intensity pace for 2 minutes every 20 minutes. And in the third trial condition, they walked on a treadmill at moderate-intensity pace for 2 minutes every 20 minutes. Key Finding Importantly, the researchers found that the benefit of walking at a light intensity pace was almost identical to walking at a moderate intensity pace , suggesting that it was not so much the amount of effort put into the break that was critical but the act of standing up and moving and thereby reducing sitting time was intrinsically beneficial.  Dunstan said; “We were encouraged to see people getting a tangible benefit from breaking up their sitting time with light-intensity activity. We appreciate that it’s not very common to find a treadmill in the workplace and how difficult it would be for people to engage in reasonably vigorous movement in the office. Just standing up regularly, walking to the printer, using the stairs instead of an elevator and standing while on the phone are all likely to deliver a benefit.” “As recently as two decades ago, people were moving more frequently throughout the day in the workplace. Prior to email, people had to collect mail from a pigeon hole, or walk over to people’s desks for a chat. I think we’ve reached a crisis point where we need to step back and acknowledge that sitting for long periods is not what our bodies were designed for.” The researchers concluded that regularly breaking up sitting time by standing up more, finding ways to move about and generally being more active instead of sitting could prove to be an important public health and clinical intervention strategy for reducing cardiovascular risk. Editor's Note: Original news release can be found here.