We are led to question whether the recommended social distancing measures to prevent SARS-CoV-2 transmission could increase the number of other serious instabilities. The breaking of the contagion pathways reduces the sharing of microorganisms between people, thus favoring dysbiosis, which, in turn, may increase the poor prognosis of the disease. #covid #microbiome #dysbiosis Célia P. F. Domingues, João S. Rebelo, Francisco Dionisio, Ana Botelho, Teresa Nogueira. The Social Distancing Imposed To Contain COVID-19 Can Affect Our Microbiome: a Double-Edged Sword in Human Health. mSphere, 2020; 5 (5) DOI: 10.1128/mSphere.00716-20 https://msphere.asm.org/content/5/5/e00716-20
Bacteria in Chinese pickles can prevent cavities — Ben-Gurion University study
According to the study published in Frontiers in Microbiology, a strain of Lactobacilli (L. plantarum K41) found in Sichuan pickles reduced S. mutans by 98.4%. Dental caries (cavities) are caused by Streptococcus mutans, (S. mutans) commonly found in the human oral cavity as plaque and is a significant contributor to tooth decay.
#cavities # Lactobacillusplantarum # streptococcus
Guojian Zhang et al. Inhibition of Streptococcus mutans Biofilm Formation and Virulence by Lactobacillus plantarum K41 Isolated From Traditional Sichuan Pickles, Frontiers in Microbiology (2020). DOI: 10.3389/fmicb.2020.00774
Ghanaian Quinine Completely Eliminated Lyme Disease bacteria in vitro
Remarkably, a single 7-day treatment with 1% Ghanaian quinine could completely eradicate the bacterium – it did not regrow, even under optimal conditions in the drug’s absence.
#lymedisease #botanical #treatment
Feng Jie, Leone Jacob, Schweig Sunjya, Zhang Ying, Evaluation of Natural and Botanical Medicines for Activity Against Growing and Non-growing Forms of B. burgdorferi, Frontiers in Medicine VOLUME 7 2020 https://www.frontiersin.org/article/10.3389/fmed.2020.00006 DOI 10.3389/fmed.2020.00006
Organically and Conventionally grown Apples are very different
“Escherichia-Shigella — a group of bacteria that includes known pathogens — was found in most of the conventional apple samples, but none from organic apples. For beneficial Lactobacilli — of probiotic fame — the reverse was true.” And there may even be vindication for those who can “taste the difference” in organic produce.
#Apple #organic #conventional
Birgit Wassermann, Henry Müller, Gabriele Berg. An Apple a Day: Which Bacteria Do We Eat With Organic and Conventional Apples? Frontiers in Microbiology, 2019; 10 DOI: 10.3389/fmicb.2019.01629
Performance-enhancing bacteria may increase performance by 13%
They pinpointed one specific group of bacteria, called Veillonella, that they found was enriched in the gut microbiome of Boston Marathon runners after after completing the 26.2 race and in an independent group of 87 elite and Olympic athletes after competitions. Veillonella bacteria isolated from marathon athletes and given to mice increased the animals’ performances in laboratory treadmill tests by 13% compared to control bacteria.
Jonathan Scheiman, Jacob M. Luber, Theodore A. Chavkin, Tara MacDonald, Angela Tung, Loc-Duyen Pham, Marsha C. Wibowo, Renee C. Wurth, Sukanya Punthambaker, Braden T. Tierney, Zhen Yang, Mohammad W. Hattab, Julian Avila-Pacheco, Clary B. Clish, Sarah Lessard, George M. Church, Aleksandar D. Kostic. Meta-omics analysis of elite athletes identifies a performance-enhancing microbe that functions via lactate metabolism. Nature Medicine, 2019; DOI: 10.1038/s41591-019-0485-4
Lupus strongly linked to imbalances in gut microbiome
The new study, publishing in the Annals of Rheumatic Diseases online Feb. 19, showed that 61 women diagnosed with SLE had roughly five times more gut bacteria known as Ruminococcus gnavus, than 17 women of similar ages and racial backgrounds who did not have the disease and were healthy.
Alternatively, Silverman says, new treatments could also be used to promote growth of Bacteroides uniformis, bacteria thought to hinder growth of R. gnavus in the gut…..
#lupus #microbiome #Ruminococcus
Doua Azzouz, Aidana Omarbekova, Adriana Heguy, Dominik Schwudke, Nicolas Gisch, Brad H. Rovin, Roberto Caricchio, Jill P. Buyon, Alexander V. Alekseyenko, Gregg J. Silverman. Lupus nephritis is linked to disease-activity associated expansions and immunity to a gut commensal. Annals of the Rheumatic Diseases, 2019; annrheumdis-2018-214856 DOI: 10.1136/annrheumdis-2018-214856
A DRINK derived from a vegetable has been hailed as a breakthrough in the search for a cure for flu.
Published: Wed, November 6, 2013
Flu could soon be banished by a landmark scientific discovery [GETTY: Pic posed by model]
When a particular strain of Lactobacillus brevis is eaten by mice, it has protective effects against influenza
They discovered that a strain of bacteria in pickled turnip, a dish popular in Japan, boosts immunity to the virus. Experts are already carrying out human trials on a probiotic drink which contains the powerful new ingredient.
The development comes as a leading British expert has warned that the UK is facing one of the worst winter flu tolls for years, with up to 4,000 deaths.
If the research proves effective, a huge number of lives could be saved by people protecting themselves with a probiotic drink, similar to those drunk daily to boost good bacteria in the gut.
Japanese turnips are hailed as the new health wonder [ALAMY]
The bacteria increased the production of immune system moleclues, including flu-specific antibodies. In mice, the effects were powerful enough to prevent infection by the highly contagious H1N1 swine flu. Scientists at research company Kagome believe there could also be protection against the deadly H7N9 strain which has recently emerged in China.
While suguki fans hail its protective powers, it is unknown why the bacteria protects against flu, but it was found to be extremely tolerant to acidic stomach juices.
It is not known whether the same effects will be seen in humans but scientists are hopeful they have found the next superfood.
Scientists warn this year could be the worst for flu deaths [GETTY: Pic posed by model]
The research concluded: “Continual intake of (the drink) for 14 days prior to influenza virus infection alleviated symptoms such as loss of body weight and deterioration in observational physical conditions induced by the infection.”
Ms Waki said further studies are needed to confirm initial findings. Human trials are now under way.
Last month, virologist Professor John Oxford, of Queen Mary University in London, said Britain had “got away with it” recently and predicted this would be the worst winter for flu deaths for years.
He warned doctors and other health staff to improve the shockingly low levels of flu jabs among their ranks, which greatly increases the chances of flu spreading.
Many Britons have limited immunity after several years of relatively low-level outbreaks.
Analysts at Datamonitor Healthcare are forecasting that 10.5 million people will get flu this winter. The virus is most deadly to the elderly and very young.
University of Michigan study helps explain benefits of probiotics for patients with stress-associated gastrointestinal disorders
ANN ARBOR, Mich. – For those with irritable bowel syndrome who wonder if stress aggravates their intestinal disorder, a new University of Michigan Health System study shows it’s not all in their head.
Researchers revealed that while stress does not cause IBS, it does alter brain-gut interactions and induces the intestinal inflammation that often leads to severe or chronic belly pain, loss of appetite and diarrhea.
Stress has a way of suppressing an important component called an inflammasome which is needed to maintain normal gut microbiota, but probiotics reversed the effect in animal models, according to findings published online ahead of print in Gastroenterology.
“The effect of stress could be protected with probiotics which reversed the inhibition of the inflammasome,” says senior study author and gastroenterologist John Y. Kao, M.D., associate professor of internal medicine at the University of Michigan. “This study reveals an important mechanism for explaining why treating IBS patients with probiotics makes sense.”
Probiotics are live bacteria that help grow the gut-dwelling “good” bacteria that keep pathogens in check, aid digestion and nutrient absorption and contribute to immune function.
U-M researchers including Chung Owyang, M.D., chief of the U-M Division of Gastroenterology, Gary Huffnagle, Ph.D., professor of pulmonary and critical care, and infectious disease expert Vincent Young, M.D., Ph.D., were able to identify the way stress significantly altered the composition of gut bacteria and the role of probiotics.
Maintaining healthy microbiota requires action by nucleotide-binding oligomerization domain protein-like receptors, pyrin-domain containing (NLRP)-6 inflammasomes. But when stressed, mice produced corticotropin-releasing hormone (CRH) that prevented inflammasomes from doing their job.
Inhibiting inflammosomes alters the composition of the gut, leading to intestinal inflammation. In the study, pretreatment with probiotic therapy reduced inflammation in mice with stress-induced small bowel inflammation.
“Additional clinical study is required to determine the optimal probiotic therapy,” says Kao. “Patients can start living healthier lifestyles to improve their gut microbiota such as adding more fruits and vegetables to their diet, and looking for ways to keep stress in check.”
Reference: “Stress-induced corticotropin-releasing hormone-mediated NLRPG inflammasome inhibition and transmissible enteritis in mice, Gastroenterology, doi: 10.1053
Funding: National Institute of Diabetes and Digestive and Kidney Diseases and from the National Institute of Allergy and Infectious Diseases
A team of scientists and surgeons from Newcastle are developing a new nasal spray from a marine microbe to help clear chronic sinusitis.
They are using an enzyme isolated from a marine bacterium Bacillus licheniformis found on the surface of seaweed which the scientists at Newcastle University were originally researching for the purpose of cleaning the hulls of ships.
Publishing in PLOS ONE, they describe how in many cases of chronic sinusitis the bacteria form a biofilm, a slimy protective barrier which can protect them from sprays or antibiotics. In vitro experiments showed that the enzyme, called NucB dispersed 58% of biofilms.
Dr Nicholas Jakubovics of Newcastle University said: “In effect, the enzyme breaks down the extracellular DNA, which is acting like a glue to hold the cells to the surface of the sinuses. In the lab, NucB cleared over half of the organisms we tested.”
Sinusitis with or without polyps is one of the most common reasons people go to their GP and affects more than 10% of adults in the UK and Europe. Mr Mohamed Reda Elbadawey, Consultant of Otolaryngology Head and Neck Surgery, Freeman Hospital – part of the Newcastle Hospitals NHS Foundation Trust – was prompted to contact the Newcastle University researchers after a student patient mentioned a lecture on the discovery of NucB and they are now working together to explore its medical potential.
Mr Elbadawey said: “Sinusitis is all too common and a huge burden on the NHS. For many people, symptoms include a blocked nose, nasal discharge or congestion, recurrent headaches, loss of the sense of smell and facial pain. While steroid nasal sprays and antibiotics can help some people, for the patients I see, they have not been effective and these patients have to undergo the stress of surgery. If we can develop an alternative we could benefit thousands of patients a year.”
In the research, the team collected mucous and sinus biopsy samples from 20 different patients and isolated between two and six different species of bacteria from each individual. 24 different strains were investigated in the laboratory and all produced biofilms containing significant amounts of extracellular DNA. Biofilms formed by 14 strains were disrupted by treatment with the novel bacterial deoxyribonuclease, NucB.
When under threat, bacteria shield themselves in a slimy protective barrier. This slimy layer, known as a biofilm, is made up of bacteria held together by a web of extracellular DNA which adheres the bacteria to each other and to a solid surface – in this case in the lining of the sinuses. The biofilm protects the bacteria from attack by antibiotics and makes it very difficult to clear them from the sinuses.
In previous studies of the marine bacterium Bacillus licheniformis, Newcastle University scientists led by marine microbiologist Professor Grant Burgess found that when the bacteria want to move on, they release an enzyme which breaks down the external DNA, breaking up the biofilm and releasing the bacteria from the web. When the enzyme NucB was purified and added to other biofilms it quickly dissolved the slime exposing the bacterial cells, leaving them vulnerable.
The team’s next step is to further test and develop the product and they are looking to set up collaboration with industry.
Children with eczema have a more diverse set of bacteria in their guts than non affected children, finds a new study in BioMed Central’s open access journal BMC Microbiology. The types of bacteria present were also more typical of adult gut microbes than for toddlers without eczema.
Eczema is a chronic inflammation of the epidermis. The gut bacteria of children with or without eczema was examined when they were six and 18 months old. At six months all the infants had the same types of bacteria but by 18 months old the children with eczema had more of a type of bacteria normally associated with adults (Clostridium clusters IV and XIVa) while the healthy children had a greater amount of Bacteroidetes.
MSc Lotta Nylund from University of Turku, Finland, who led the project explained, “The composition of bacteria in a child’s gut depends on its environment and the food it eats. You would expect that as a child’s diet changes so will the bacteria present. The number of bifidobacteria naturally falls with age and in total we found 21 groups of bacteria which changed in this time period. However it is the early change towards adult-type bacteria which seems to be a risk factor for eczema.”
Dr Hilary Glover Scientific Press Officer, BioMed Central Tel: +44 (0) 20 3192 2370 Mob: +44 (0) 778 698 1967 Email: firstname.lastname@example.org
1. Microarray analysis reveals marked intestinal microbiota aberrancy in infants having eczema compared to healthy children in at-risk for atopic disease Lotta Nylund, Reetta Satokari, Janne Nikkilä, Mirjana Rajilic-Stojanovic, Marko Kalliomäki, Erika Isolauri, Seppo Salminen and Willem M de Vos BMC Microbiology (in press)
Please name the journal in any story you write. If you are writing for the web, please link to the article. All articles are available free of charge, according to BioMed Central’s open access policy.
Article citation and URL available on request on the day of publication.
2. BMC Microbiology is an open access, peer-reviewed journal that considers articles on analytical and functional studies of prokaryotic and eukaryotic microorganisms, viruses and small parasites, as well as host and therapeutic responses to them and their interaction with the environment.
3. BioMed Central (http://www.biomedcentral.com/) is an STM (Science, Technology and Medicine) publisher which has pioneered the open access publishing model. All peer-reviewed research articles published by BioMed Central are made immediately and freely accessible online, and are licensed to allow redistribution and reuse. BioMed Central is part of Springer Science+Business Media, a leading global publisher in the STM sector. @BioMedCentral
2010 study posted for filing
Short courses of antibiotics can leave normal gut bacteria harbouring antibiotic resistance genes for up to two years after treatment, say scientists writing in the latest issue of Microbiology, published on 3 November.
The researchers believe that this reservoir increases the chances of resistance genes being surrendered to pathogenic bacteria, aiding their survival and suggesting that the long-term effects of antibiotic therapy are more significant than previously thought.
Antibiotics that are prescribed to treat pathogenic bacteria also have an impact on the normal microbial flora of the human gut. Antibiotics can alter the composition of microbial populations (potentially leading to other illnesses) and allow micro-organisms that are naturally resistant to the antibiotic to flourish.
The impact of antibiotics on the normal gut flora has previously been thought to be short-term, with any disturbances being restored several weeks after treatment. However, the review into the long-term impacts of antibiotic therapy reveals that this is not always the case. Studies have shown that high levels of resistance genes can be detected in gut microbes after just 7 days of antibiotic treatment and that these genes remain present for up to two years even if the individual has taken no further antibiotics.
The consequences of this could be potentially life-threatening explained Dr Cecilia Jernberg from the Swedish Institute for Infectious Disease Control who conducted the review. “The long-term presence of resistance genes in human gut bacteria dramatically increases the probability of them being transferred to and exploited by harmful bacteria that pass through the gut. This could reduce the success of future antibiotic treatments and potentially lead to new strains of antibiotic-resistant bacteria.”
The review highlights the necessity of using antibiotics prudently. “Antibiotic resistance is not a new problem and there is a growing battle with multi-drug resistant strains of pathogenic bacteria. The development of new antibiotics is slow and so we must use the effective drugs we have left with care,” said Dr Jernberg. “This new information about the long-term impacts of antibiotics is of great importance to allow rational antibiotic administration guidelines to be put in place,” she said.
Researchers at the University of Gothenburg, Sweden, and the Chalmers University of Technology, Sweden, demonstrate that an altered gut microbiota in humans is associated with symptomatic atherosclerosis and stroke. These findings are presented in a study published in Nature Communications on December 4.
The human body contains ten times more bacterial cells than human cells, most of which are found in the gut. These bacteria contain an enormous number of genes in addition to our host genome, and are collectively known as the gut metagenome.
How does the metagenome affect our health? This question is currently being addressed by researchers in the rapidly expanding field of metagenomic research. Several diseases have been linked to variations in the metagenome.
Researchers at Chalmers University of Technology and Sahlgrenska Academy, University of Gothenburg, now also show that changes in the gut metagenome can be linked to atherosclerosis and stroke.
The researchers compared a group of stroke patients with a group of healthy subjects and found major differences in their gut microbiota. In particular, they showed that genes required for the production of carotenoids were more frequently found in gut microbiota from healthy subjects. The healthy subjects also had significantly higher levels of a certain carotenoid in the blood than the stroke survivors.
Carotenoids are a type of antioxidant, and it has been claimed for many years that they protect against angina and stroke. Thus, the increased incidence of carotenoid-producing bacteria in the gut of healthy subjects may offer clues to explain how the gut metagenome affects disease states.
Carotenoids are marketed today as a dietary supplement. The market for them is huge, but clinical studies of their efficacy in protecting against angina and stroke have produced varying results.
Jens Nielsen, Professor of Systems Biology at Chalmers, says that it may be preferable to take probiotics instead – for example dietary supplements containing types of bacteria that produce carotenoids.
“Our results indicate that long-term exposure to carotenoids, through production by the bacteria in the digestive system, has important health benefits. These results should make it possible to develop new probiotics. We think that the bacterial species in the probiotics would establish themselves as a permanent culture in the gut and have a long-term effect”.
“By examining the patient’s bacterial microbiota, we should also be able to develop risk prognoses for cardiovascular disease”, says Fredrik Bäckhed, Professor of Molecular Medicine at the University of Gothenburg. “It should be possible to provide completely new disease-prevention options”.
The researchers have now started a company, Metabogen, to further develop their discoveries relating to the metagenome. Their success is based on close cooperation between engineers, microbiologists and doctors.
Jens Nielsen and Fredrik Bäckhed both agree that one of the challenges in the rapidly developing area of metagenomics is its multidisciplinary facets, requiring novel collaborations and merging of research fields.
The paper “Symptomatic atherosclerosis is associated with an altered gut metagenome” was published on December 4.
Fredrik Bäckhed Professor of Molecular Medicine at the Sahlgrenska Academy University of Gothenburg
Jens Nielsen Professor of Systems Biology at Chalmers University of Technology 46-70-243-66-18, email@example.com
Fredrik Karlsson Research Student Systems Biology at Chalmers University of Technology 46-31-772-38-86, firstname.lastname@example.org
The research was funded by:
Knut and Alice Wallenberg Foundation, the Chalmers Foundation, Swedish Heart Lung Foundation, Torsten Söderberg’s Foundation, IngaBritt och Arne Lundbergs Foundation, AFA Insurances, the Swedish Research Council, and the Swedish Foundation for Strategic Research.
2009 study posted for filing
Contact: Emma Ross
International Association for the Study of Obesity
Study in pregnant women suggests probiotics may help ward off obesity
Amsterdam, the Netherlands: One year after giving birth, women were less likely to have the most dangerous kind of obesity if they had been given probiotics from the first trimester of pregnancy, found new research that suggests manipulating the balance of bacteria in the gut may help fight obesity.
Probiotics are bacteria that help maintain a healthy bacterial balance in the digestive tract by reducing the growth of harmful bacteria. They are part of the normal digestive system and play a role in controlling inflammation. Researchers have for many years been studying the potential of using probiotic supplementation to address a number of intestinal diseases. More recently, obesity researchers have started to investigate whether the balance of bacteria in the gut might play a role in making people fat and whether adjusting that balance could help.
“The results of our study, the first to demonstrate the impact of probiotics-supplemented dietary counselling on adiposity, were encouraging,” said Kirsi Laitinen, a nutritionist and senior lecturer at the University of Turku in Finland who presented her findings on Thursday at the European Congress on Obesity. “The women who got the probiotics fared best. One year after childbirth, they had the lowest levels of central obesity as well as the lowest body fat percentage.”
“Central obesity, where overall obesity is combined with a particularly fat belly, is considered especially unhealthy,” Laitinen said. “We found it in 25% of the women who had received the probiotics along with dietary counselling, compared with 43% in the women who received diet advice alone.”
In the study, 256 women were randomly divided into three groups during the first trimester of pregnancy. Two of the groups received dietary counselling consistent with what’s recommended during pregnancy for healthy weight gain and optimal foetal development. They were also given food such as spreads and salad dressings with monounsaturated and polyunsaturated fatty acids, as well as fibre-enriched pasta and breakfast cereal to take home. One of those groups also received daily capsules of probiotics containing Lactobacillus and Bifidobacterium, which are the most commonly used probiotics. The other group received dummy capsules. A third group received dummy capsules and no dietary counselling. The capsules were continued until the women stopped exclusive breastfeeding, up to 6 months.
The researchers weighed the women at the start of the study. At the end of the study they weighed them again and measured their waist circumference and skin fold thickness. The results were adjusted for weight at the start of the study.
Central obesity – defined as a body mass index (BMI) of 30 or more or a waist circumference over 80 centimetres – was found in 25% of the women who had been given the probiotics as well as diet advice. That compared with 43% of the women who got dietary counselling alone and 40% of the women who got neither diet advice nor probiotics. The average body fat percentage in the probiotics group was 28%, compared with 29% in the diet advice only group and 30% in the third group.
Laitinen said further research is needed to confirm the potential role of probiotics in fighting obesity. One of the limitations of the study was that it did not control for the mothers’ weight before pregnancy, which may influence how fat they later become.
She said she and her colleagues will continue to follow the women and their babies to see whether giving probiotics during pregnancy has any influence on health outcomes in the children.
“The advantage of studying pregnant women to investigate the potential link between probiotics and obesity is that it allows us to see the effects not only in the women, but also in their children,” she said. “Particularly during pregnancy, the impacts of obesity can be immense, with the effects seen both in the mother and the child. Bacteria are passed from mother to child through the birth canal, as well as through breast milk and research indicates that early nutrition may influence the risk of obesity later in life. There is growing evidence that this approach might open a new angle on the fight against obesity, either through prevention or treatment.”
Latinen’s study was funded by the Social Insurance Institution of Finland, the Academy of Finland and the Sigrid Juselius Foundation, a Finnish medical research charity.
Catalogue no: T1:RS1.3 oral presentation, Elicium 2, 09.30 hrs CET Thursday 7 May.
2009 report posted for filing
Saranac Lake, N.Y., -Dr. Marcia Blackman and her research team at the Trudeau Institute have followed up on an intriguing report(1)published in the journal Nature in May 2007 by Dr. Herbert Virgin, et al., showing that mice persistently infected with certain forms of herpesvirus, which can establish lifelong latent infections, are resistant to infection with bacterial pathogens.
Although herpesvirus infections are generally considered undesirable and can be associated with declining immune function in the elderly or the development of a variety of tumors later in life, the Virgin report raised the unexpected possibility that they may also be beneficial.
Dr. Blackman’s research has now confirmed Dr. Virgin’s findings, but with some further refinements about herpes’ roles in preventing other infections: “We discovered that the effect of herpesvirus infection is transient, lasting only a few months. Interestingly, although the effect was shown by the Virgin group to be dependent on establishing a latent infection, it wanes despite lifelong latency.”
Recognizing that her data had implications for the interpretation of Dr. Virgin’s data, Dr. Blackman shared her findings with the Virgin group prior to publication. This led to an interesting exchange between the two labs in the form of letters to the editor regarding the potential benefits of a transient protective effect. The letters will be published concurrently with Blackman’s data in the February issue of Viral Immunology (Vol. 22, No.1). The scientists agree that even short-acting protection, especially during childhood, might have long-lasting implications in terms of survival rates.
A major point of discussion between the two groups concerned the implications of such research for the development of vaccines against herpesvirus infections. Dr. Virgin suggested that “decreased infection may be associated with unintended negative consequences for vaccinated individuals.” In response, Dr. Blackman argues that possible transient protective effects did not outweigh the already recognized pathological consequences of herpesvirus infection. Both groups agreed that the protective effects of herpesvirus infections merit further study.
Importantly, both groups hope their observations will stimulate epidemiological and clinical studies to determine whether herpesvirus infections really protect humans against bacterial diseases.
(1)“Herpesvirus latency confers symbiotic protection from bacterial infection,” NATURE, Vol. 447, pp. 326-29; May 17, 2007.
Published in Letters in Applied Microbiology
Wheat-based infant follow-on formulas are better reconstituted with fruit juice and should be stored in the fridge at 4°C to prevent growth of meningitis bacteria, according to recent research.
The results of a study, published today in the Society for Applied Microbiology journal, Letters in Applied Microbiology, have shown that Cronobacter species do not grow in wheat-based infant formula stored at 4°C.
Cronobacter is a recently defined genus of bacteria and was previously known as Enterobacter sakazakii. Cronobacter species have been frequently isolated from the environment and various food products including infant formula. These bacteria have been associated with infant meningitis, enteritis and septicaemia, so prevention of infant’s consumption is vital in maintaining their safety.
These bugs will grow at 25°C or 37°C, but less so when the formula is made up using apple or grape juice than when made up using water or milk.
“This is valuable information for parents, infant formula producers and regulators and should be used when preparing and storing the reconstituted wheat based infant formula. It is also important that formula is prepared hygienically” said researcher Tareq Osaili.
2008 Study posted for filing
Chemicals used in the environment to kill bacteria could be making them stronger, according to a paper published in the October issue of the journal Microbiology. Low levels of these chemicals, called biocides, can make the potentially lethal bacterium Staphylococcus aureus remove toxic chemicals from the cell even more efficiently, potentially making it resistant to being killed by some antibiotics.
Biocides are used in disinfectants and antiseptics to kill microbes. They are commonly used in cleaning hospitals and home environments, sterilizing medical equipment and decontaminating skin before surgery. At the correct strength, biocides kill bacteria and other microbes. However, if lower levels are used the bacteria can survive and become resistant to treatment.
“Bacteria like Staphylococcus aureus make proteins that pump many different toxic chemicals out of the cell to interfere with their antibacterial effects,” said Dr Glenn Kaatz from the Department of Veterans Affairs Medical Center in Detroit, USA. “These efflux pumps can remove antibiotics from the cell and have been shown to make bacteria resistant to those drugs. We wanted to find out if exposure to biocides could also make bacteria resistant to being killed by the action of efflux pumps.”
The researchers exposed S. aureus taken from the blood of patients to low concentrations of several biocides and dyes, which are also used frequently in hospitals. They looked at the effect of exposure on the bacteria and found that mutants that make more efflux pumps than normal were produced.
“We found that exposure to low concentrations of a variety of biocides and dyes resulted in the appearance of resistant mutants,” said Dr Kaatz. “The number of efflux pumps in the bacteria increased. Because the efflux pumps can also rid the cell of some antibiotics, pathogenic bacteria with more pumps are a threat to patients as they could be more resistant to treatment.”
If bacteria that live in protected environments are exposed to biocides repeatedly, for example during cleaning, they can build up resistance to disinfectants and antibiotics. Such bacteria have been shown to contribute to hospital-acquired infections.
“Scientists are trying to develop inhibitors of efflux pumps. Effective inhibitors would reduce the likelihood of additional resistance mechanisms emerging in bacteria,” said Dr Kaatz. “Unfortunately, inhibitors evaluated to date do not work on a wide range of pathogens so they are not ideal to prevent resistance.”
“Careful use of antibiotics and the use of biocides that are not known to be recognised by efflux pumps may reduce the frequency at which resistant strains are found,” said Dr Kaatz. “Alternatively, the combination of a pump inhibitor with an antimicrobial agent or biocide will reduce the emergence of such strains and their clinical impact.”
Newly developed technique can kill antibiotic-resistant germs
Sept. 24, 2012
Timothy Wall, email@example.com, 573-882-3346
COLUMBIA, Mo. — Infectious bacteria received a taste of their own medicine from University of Missouri researchers who used viruses to infect and kill colonies of Pseudomonas aeruginosa, common disease-causing bacteria. The viruses, known as bacteriophages, could be used to efficiently sanitize water treatment facilities and may aid in the fight against deadly antibiotic-resistant bacteria.
“Our experiment was the first to use bacteriophages in conjunction with chlorine to destroy biofilms, which are layers of bacteria growing on a solid surface,” said Zhiqiang Hu, associate professor of civil and environmental engineering in MU’s College of Engineering. “The advantage to using viruses is that they can selectively kill harmful bacteria. Beneficial bacteria, such as those used to break down wastes in water treatment plants, are largely unaffected. Hence, viruses could be used to get rid of pathogenic bacteria in water filters that would otherwise have to be replaced. They could save taxpayers’ money by reducing the cost of cleaning water.”
Bacteria can be difficult to kill when they form a biofilm. The outer crust of bacteria in these biofilms can be killed by chlorine, but the inner bacteria are sheltered. Viruses solve this problem because they spread through an entire colony of bacteria. Hu noted that the bacteriophages are easier to create than the enzymes used to attack biofilms. The viruses also are better at targeting specific bacterial species.
Hu, along with MU’s recent graduate, Yanyan Zhang, found the greatest success in killing biofilms by using a combination of bacteriophages and chlorine. An initial treatment with viruses followed by chlorine knocked out 97 percent of biofilms within five days of exposure. When used alone, viruses removed 89 percent of biofilms, while chlorine removed only 40 percent.
“The methods we used to kill Pseudomonas aeruginosa could be used against other dangerous bacteria, even those that have developed resistance to antibiotics,” said Hu. “Our work opened the door to a new strategy for combating the dangers and costs of bacterial biofilms. The next step is to expand our experiment into a pilot study.”
The study “Combined Treatment of Pseudomonas aeruginosa Biofilms with Bacteriophages and Chlorine” has been published in the journal Biotechnology and Bioengineering.
Scientists in Japan have discovered a new species of bacteria that can live in hairspray, according to the results of a study published in the March issue of the International Journal of Systematic and Evolutionary Microbiology.
“Contamination of cosmetic products is rare but some products may be unable to suppress the growth of certain bacteria,” says Dr Bakir from the Japan Collection of Microorganisms, Saitama, Japan. “We discovered a new species of bacteria called Microbacterium hatanonis, which we found contaminates hairspray.”
“We also found a related species, Microbacterium oxydans in hairspray which was originally isolated from hospital material. Microbacterium species have been identified in milk, cheese, beef, eggs and even in the blood of patients with leukaemia, on catheters and in bone marrow.”
The scientists looked at the appearance and diet of the bacterium, then analysed its genome to show that it is an entirely new species. “It has been named in honour of Dr Kazunori Hatano, for his contribution to the understanding of the genus Microbacterium,” says Dr Bakir. Microbacterium hatanonis is rod-shaped and grows best at 30°C and pH neutral.
Scientists now need to determine the clinical importance of the new species, as similar bacteria have been found to infect humans. “Further testing will establish whether the species is a threat to human health,” says Dr Bakir. “We hope our study will benefit the formulation of hairspray to prevent contamination in the future.”
Digested coconut oil is able to attack the bacteria that cause tooth decay. It is a natural antibiotic that could be incorporated into commercial dental care products, say scientists presenting their work at the Society for General Microbiology’s Autumn Conference at the University of Warwick.
The team from the Athlone Institute of Technology in Ireland tested the antibacterial action of coconut oil in its natural state and coconut oil that had been treated with enzymes, in a process similar to digestion. The oils were tested against strains of Streptococcus bacteria which are common inhabitants of the mouth. They found that enzyme-modified coconut oil strongly inhibited the growth of most strains of Streptococcus bacteria including Streptococcus mutans – an acid-producing bacterium that is a major cause of tooth decay.
Many previous studies have shown that partially digested foodstuffs are active against micro-organisms. Earlier work on enzyme-modified milk showed that it was able to reduce the binding of S. mutans to tooth enamel, which prompted the group to investigate the effect of other enzyme-modified foods on bacteria.
Further work will examine how coconut oil interacts with Streptococcus bacteria at the molecular level and which other strains of harmful bacteria and yeasts it is active against. Additional testing by the group at the Athlone Institute of Technology found that enzyme-modified coconut oil was also harmful to the yeast Candida albicans that can cause thrush.
The researchers suggest that enzyme-modified coconut oil has potential as a marketable antimicrobial which could be of particular interest to the oral healthcare industry. Dr Damien Brady who is leading the research said, “Dental caries is a commonly overlooked health problem affecting 60-90% of children and the majority of adults in industrialized countries. Incorporating enzyme-modified coconut oil into dental hygiene products would be an attractive alternative to chemical additives, particularly as it works at relatively low concentrations. Also, with increasing antibiotic resistance, it is important that we turn our attention to new ways to combat microbial infection.”
The work also contributes to our understanding of antibacterial activity in the human gut. “Our data suggests that products of human digestion show antimicrobial activity. This could have implications for how bacteria colonize the cells lining the digestive tract and for overall gut health,” explained Dr Brady. “Our research has shown that digested milk protein not only reduced the adherence of harmful bacteria to human intestinal cells but also prevented some of them from gaining entrance into the cell. We are currently researching coconut oil and other enzyme-modified foodstuffs to identify how they interfere with the way bacteria cause illness and disease,” he said.
The bacteria responsible for the plague and some forms of food poisoning “paralyze” the immune system of their hosts in an unexpected way, according to a new study in the September 8, 2006 issue of the journal Cell, published by Cell Press.
The researchers found that these bacteria, which belong to the genus Yersinia, harbor a protein that mimics an apparently unrelated mammalian enzyme. That copycat protein blocks host cells’ capacity to change shape and move, abilities important for cells of the immune system to track down and “eat” foreign invaders, the researchers explained.
The discovery marks the second way in which this protein, called YpkA, compromises the immune system. Earlier studies suggested that another portion of YpkA–which may have been derived from a mammalian enzyme and later co-opted by Yersinia–has activity that also influences cell shape by a separate, though incompletely understood mechanism.
The findings offer important new insight into the factors that lend Yersinia their ability to spawn disease, the researchers said. The results might also contribute to new strategies for fighting the bug.
“Yersinia injects several virulence factors into its host,” said C. Erec Stebbins of Rockefeller University. “If we can discover which ones are critical, we might identify the pathogen’s Achilles heel–an attractive target for antibacterial or anti-virulence compounds.”
“We were quite excited to see such a critical and unexpected factor in the virulence of Yersinia–a bacteria historically responsible for some of the worst diseases,” he added. Although improvements in sanitation have eliminated acute problems from diseases caused by Yersinia, concerns remain about the possibility that an untreatable strain might arise or that the bacteria might come into use as a biological weapon, he said.
Nearly 200 million people are estimated to have died in the plague epidemics that devastated the ancient world, the researchers said. The successful weaponization of plague in the former Soviet Union bioweapons program also made the pathogen a primary biodefense concern. Additional medical concerns have arisen from the evolution of multidrug-resistant strains of the plague bacterium found in patients from several locations.
The plague bacterium Yersinia pestis is closely related to Y. enterocolitica and Y. pseudotuberculosis, which are food-borne agents that cause inflammation of the stomach and intestines. All Yersinia bacteria have a virulence plasmid, which is necessary to cause disease. Plasmids are extra DNA molecules frequently found in bacteria containing genes that can be passed from one bacterial strain to another and that may confer an evolutionary advantage, such as antibiotic resistance.
In the case of Yersinia, the plasmid harbors numerous genes, including a large number that contribute to the ability of diverse pathogens to deliver virulence factors into host cells. One of these genes is YpkA, a protein with multiple domains, including one closely related to an enzyme, a type of kinase, not typically found in bacteria. Earlier studies found that mutations that eliminate this activity reduce but do not eliminate YpkA’s ability to disrupt cell shape by modifying their cytoskeletal support system.
In the current study, the researchers solved the high-resolution crystal structure of a second YpkA domain, the “Rho-GTPase binding domain” along with the host protein, “Rac1,” with which it interacts.
“The Yersinia structure was doing things to Rac1 that the host proteins normally do,” Stebbins said, suggesting that the domain acted as a mimic.
Further examination confirmed the domain to be a mimic of mammalian “guanidine nucleotide dissociation inhibitor” (GDI) proteins with a critical role in the bacteria’s ability to disrupt cell structure. The domain paralyzes cells by acting as an “off-switch” for host proteins involved in modifying cell shape, Stebbins said.
Mutations that prevented the bacterial proteins’ interaction with the host protein significantly impaired YpkA’s ability to disrupt the cytoskeleton. Moreover, a mutant strain of Y. pseudotuberculosis that lacked the GDI activity caused significantly fewer problems for infected mice compared to normal bacteria.
“Earlier studies that focused only on the protein’s kinase activity had missed half the picture,” Stebbins said. “The GDI domain seems to have an even bigger effect on host cells in culture, and a significant impact on virulence.”
The results also add to broader themes in the evolution of bacterial diseases, the researchers added.
“It is becoming increasingly clear that a common strategy used by bacterial pathogens to manipulate host cell biology is the mimicry of their own biochemical processes,” Stebbins said.
The researchers include Gerd Prehna and C. Erec Stebbins of Rockefeller University in New York, NY; Maya I. Ivanov and James B. Bliska and of Stony Brook University in Stony Brook, NY.
This work was funded in part by research funds to C.E.S. from the Rockefeller University and PHS grants 1U19AI056510 (to C.E.S) and RO1AI433890 (to J.B.B) from the National Institute of Allergy and Infectious Diseases.
Prehna et al.: “Virulence in Yersinia Is Dependent on a Bacterial Mimic of Host Rho-Family Nucleotide Dissociation Inhibitors.” Publishing in Cell 126, 869–880, September 8, 2006. DOI 10.1016/j.cell.2006.06.056 http://www.cell.com
Repost at Request 2006
CORVALLIS, Ore. – A new study suggests that nicotinamide, more commonly known as vitamin B3, may be able to combat some of the antibiotic-resistance staph infections that are increasingly common around the world, have killed thousands and can pose a significant threat to public health.
The research found that high doses of this vitamin increased by 1,000 times the ability of immune cells to kill staph bacteria. The work was done both in laboratory animals and with human blood.
The findings were published today in the Journal of Clinical Investigation by researchers from Cedars-Sinai Medical Center, the Linus Pauling Institute at Oregon State University, UCLA, and other institutions. The research was supported by several grants from the National Institutes of Health.
The work may offer a new avenue of attack against the growing number of “superbugs.”
“This is potentially very significant, although we still need to do human studies,” said Adrian Gombart, an associate professor in OSU’s Linus Pauling Institute. “Antibiotics are wonder drugs, but they face increasing problems with resistance by various types of bacteria, especially Staphylococcus aureus.
“This could give us a new way to treat staph infections that can be deadly, and might be used in combination with current antibiotics,” Gombart said. “It’s a way to tap into the power of the innate immune system and stimulate it to provide a more powerful and natural immune response.”
The scientists found that clinical doses of nicotinamide increased the numbers and efficacy of “neutrophils,” a specialized type of white blood cell that can kill and eat harmful bacteria.
The nicotinamide was given at megadose, or therapeutic levels, far beyond what any normal diet would provide – but nonetheless in amounts that have already been used safely in humans, as a drug, for other medical purposes.
However, there is no evidence yet that normal diets or conventional-strength supplements of vitamin B3 would have any beneficial effect in preventing or treating bacterial infection, Gombart said, and people should not start taking high doses of the vitamin.
Gombart has been studying some of these issues for more than a decade, and discovered 10 years ago a human genetic mutation that makes people more vulnerable to bacterial infections. In continued work on the genetic underpinnings of this problem, researchers found that nicotinamide had the ability to “turn on” certain antimicrobial genes that greatly increase the ability of immune cells to kill bacteria.
One of the most common and serious of the staph infections, called methicillin-resistant S. aureus, or MRSA, was part of this study. It can cause serious and life-threatening illness, and researchers say the widespread use of antibiotics has helped increase the emergence and spread of this bacterial pathogen.
Dr. George Liu, an infectious disease expert at Cedars-Sinai and co-senior author on the study, said that “this vitamin is surprisingly effective in fighting off and protecting against one of today’s most concerning public health threats.” Such approaches could help reduce dependence on antibiotics, he said.
Co-first authors Pierre Kyme and Nils Thoennissen found that when used in human blood, clinical doses of vitamin B3 appeared to wipe out the staph infection in only a few hours.
Serious staph infections, such as those caused by MRSA, are increasingly prevalent in hospitals and nursing homes, but are also on the rise in prisons, the military, among athletes, and in other settings where many people come into close contact
Rogue bacteria involved in both heart disease and infertility
Researcher uncovers how chlamydia sabotages human immunity
Chlamydia pneumoniae is a microbe that normally causes pneumonia and bronchitis, but it has long been associated with atherosclerosis, a cardiovascular disease also called “hardening of the arteries.”
“It was a frightening prospect,” says Azenabor, “that atherosclerosis could come from a bacterial infection.” He decided to look for an explanation.
Chlamydiae are unusual, says the Nigerian-born scientist, because, unlike most other bacteria, they use the same form of cholesterol for metabolism that human cells use. Chlamydiae also are intracellular pathogens, meaning that they can only grow and reproduce inside of another cell.
But these bacteria have another peculiar ability.
Normally, when a pathogen invades human tissue, the immune response unleashes “killer cells” called macrophages, which stretch to engulf the attacker and destroy it with toxin-producing enzymes.
Chlamydiae fight back, says Azenabor, His work shows that, as they are ingested, these two species of Chlamydia can manipulate the functions of protective cells like macrophages in creative ways.
One of the keys lies in the macrophages’ cell walls, which store cholesterol and usually tightly control it.
But when it’s infected with C. pneumoniae, the microbe traffics cholesterol from the macrophage cell membrane to its own, causing a change in the macrophage that makes it rigid and unable to move.
The bacterium also disturbs the macrophage’s production of toxins in a process that transforms them into “signaling molecules,” which support functions that keep the bacterium alive.
“C. pneumoniae really wants to hijack the cell functions for its own use, like a parasite would,” he says. “The macrophage, though, wants to kill Chlamydia, but its killing ability has been converted to signaling.”
This is the reason the infection becomes chronic, Azenabor says. “Because of signaling, everything else in the human cell is still fine except for the altered toxins, so the bacteria can reproduce in a short time.”
As the macrophages become immobile, they accumulate in the blood vessel walls, setting the stage for atherosclerosis.
Infection and pregnancy
Armed with new information about how C. pneumoniae sabotages the immune response, Azenabor, who had also been studying the effects of estrogen on macrophages, turned his attention to another Chlamydia-related puzzle.
How is Chlamydia trachomatis, the species that causes a sexually transmitted disease, involved in the occurrence of spontaneous abortions or miscarriages?
He was immediately drawn to the protective cells in the placenta during early pregnancy – the trophoblasts.
“It’s not for nothing that trophoblasts are the early cells,” says Azenabor. “They prevent any kind of infection that could threaten the fertilized egg. They produce toxic chemicals similar to those of macrophages.”
Trophoblasts act like macrophages in many ways, and their functions are mediated by the hormones estrogen and progesterone. And cholesterol is the molecule used to produce those hormones.
Azenabor’s research shows that, like its cousin, C. trachomatis does take cholesterol from the trophoblast, and it also reproduces once inside the cell.
“It’s the same old story,” says Azenabor. “Only this time the attacked cell is a trophoblast instead of a macrophage, and the depleted cholesterol hinders production of estrogen and progesterone instead of altering toxin production.”
Azenabor’s lab members are continuing their inquiry, and they then will need to test the theories with live animals.
But the scientist is optimistic. Already he has a patented process for blocking the effects of calcium signaling for C. pneumoniae.
“If we can prevent C. trachomatis from becoming chronic, we could apply this remedy to pregnancy,” he says.
While conducting postdoctoral work at McMaster University in Ontario, he won the Canadian Distinguished Scientist Award in 1998, and moved to the University of Waterloo.
Azenabor joined the UWM faculty in 2001, after working as a scientist in a Chlamydia lab at UW–Madison. He jumped at the chance to start his own lab at UWM. Since arriving here he has won several honors, including the Shaw Distinguished Scientist Award from the James D. and Dorothy Shaw Fund in the Greater Milwaukee Foundation.
Although he didn’t plan on working with Chlamydia for this long, he is now a leading researcher in the field. One attraction, he says, is the work is unpredictable.
“When you begin,” he says, “you never know where you are going to go.”
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