Neonatal meningitis: the immaturity of microbiota and epithelial barriers implicated
2021-07-09
(Press-News.org) Meningitis is associated with high mortality and frequently causes severe sequelae. Newborn infants are particularly susceptible to this type of infection; they develop meningitis 30 times more often than the general population. Group B streptococcus (GBS) bacteria are the most common cause of neonatal meningitis, but they are rarely responsible for disease in adults. Scientists from the Institut Pasteur, in collaboration with Inserm, Université de Paris and Necker-Enfants Malades Hospital (AP-HP), set out to explain neonatal susceptibility to GBS meningitis. In a mouse model, they demonstrated that the immaturity of both the gut microbiota and epithelial barriers such as the gut and choroid plexus play a role in the susceptibility of newborn infants to bacterial meningitis caused by GBS. The findings were published in the journal Cell Reports on June 29, 2021.
Newborn infants are more likely to develop bacterial meningitis than children and adults. Group B streptococcus (GBS) is the pathogen responsible for a significant proportion of cases of neonatal meningitis. In most instances, infection is preceded by bacterial colonization of the gut. The commensal bacterial gut flora (known as the microbiota) plays a key physiological role, as it is involved in digestion, offers protection from gut pathogens and contributes to tissue differentiation and immune development. Newborns have no gut microbiota; it gradually develops in the first few weeks after birth.
In a new study, scientists from the Institut Pasteur, in collaboration with Inserm, Université de Paris and Necker-Enfants malades Hospital (AP-HP), demonstrated in a mouse model that the immaturity of the gut microbiota in neonates is involved in neonatal susceptibility to meningitis caused by GBS. In the absence of a mature microbiota, the bacteria can extensively colonize the gut. In the absence of a mature microbiota, the barrier function of blood vessels in the gut that the bacteria must cross to reach the brain through the bloodstream is also less effective, and the immune system is unable to control infection.
Unexpectedly, the scientists also demonstrated that, independently of the microbiota, the epithelial barriers formed by the gut and the choroid plexus (the interface between the blood and the cerebrospinal fluid that irrigates the brain) are not entirely mature in newborns, which facilitates bacterial access to the brain. The signaling pathway known as the Wnt pathway, which is involved in tissue growth and differentiation, is more active in newborns, resulting in a less effective barrier function at the gut and choroid plexus levels in neonates.
"In this study, we show how two factors associated with infancy - the immaturity of the gut microbiota and the growth of gut and choroidal epithelial tissues - play a role in the susceptibility of newborn infants to meningitis caused by GBS, at all stages of infection from gut colonization to dissemination in the brain," explains Marc Lecuit (university professor/hospital practitioner, Université de Paris and Necker-Enfants Malades Hospital), head of the Biology of Infection Unit at the Institut Pasteur and Inserm and last author of the study.
The results of this research illustrate the importance of the microbiota and its critical role in protecting against infection.
INFORMATION:
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
2021-07-09
The Delta variant was detected for the first time in India in October 2020 and has since spread throughout the world. It is now dominant in many countries and regions (India, the UK, Portugal, Russia, etc.) and is predicted to be the most prevalent variant in Europe within weeks or months. Epidemiological studies have shown that the Delta variant is more transmissible than other variants. Scientists from the Institut Pasteur (CNRS joint unit), in collaboration with Hôpital Européen Georges Pompidou (part of the Paris Public Hospital Network or AP-HP), Orléans Regional Hospital and Strasbourg University Hospital, studied the sensitivity of the Delta variant ...
2021-07-09
To enable tissue renewal, human tissues constantly eliminate millions of cells, without jeopardizing tissue integrity, form and connectivity. The mechanisms involved in maintaining this integrity remain unknown. Scientists from the Institut Pasteur and the CNRS today revealed a new process which allows eliminated cells to temporarily protect their neighbors from cell death, thereby maintaining tissue integrity. This protective mechanism is vital, and if disrupted can lead to a temporary loss of connectivity. The scientists observed that when the mechanism is deactivated, the simultaneous elimination of ...
2021-07-09
New Brunswick, N.J. (July 9, 2021) -- A massive volcanic eruption in Indonesia about 74,000 years ago likely caused severe climate disruption in many areas of the globe, but early human populations were sheltered from the worst effects, according to a Rutgers-led study.
The findings appear in the journal PNAS.
The eruption of the Toba volcano was the largest volcanic eruption in the past two million years, but its impacts on climate and human evolution have been unclear. Resolving this debate is important for understanding environmental changes during a key interval in human evolution.
"We were able to use a large number of climate model simulations to resolve what seemed like a paradox," said lead author Benjamin Black, an assistant professor in the Department ...
2021-07-09
Changing climate patterns have left millions of people vulnerable to weather extremes. As temperature fluctuations become more commonplace around the world, conventional power-guzzling cooling and heating systems need a more innovative, energy-efficient alternative, and in turn, lessen the burden on already struggling power grids.
In a new study, researchers at Texas A&M University have created novel 3D printable phase-change material (PCM) composites that can regulate ambient temperatures inside buildings using a simpler and cost-effective manufacturing process. Furthermore, these composites can be added to building materials, like paint, or 3D printed as decorative home accents to seamlessly integrate into different indoor environments.
"The ability to integrate phase-change materials ...
2021-07-09
We know that turning goals into a game can increase people's physical activity. We also know that financial incentives can be effective, especially when they're framed in a way where people lose money if they don't reach their goals. But a new Perelman School of Medicine at the University of Pennsylvania study adds to evidence that combining the two can result in significant gains.
Researchers affiliated with Penn Medicine's Center for Health Care Innovation showed that a group of veterans who were overweight or obese and receiving care from a Philadelphia hospital were able to increase their daily step counts by more than 1,200, on average, when their personalized goals were paired with a game in which they received support from a buddy, all while they stood ...
2021-07-09
What The Study Did: This survey study examined disparities in COVID-19 vaccine acceptance and approaches to improve vaccination rates among adults in China.
Authors: Jingjing Ma, Ph.D., of Peking University in Beijing, is the corresponding author.
To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/
(doi:10.1001/jamahealthforum.2021.1466)
Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.
INFORMATION:
Media advisory: The full study is linked ...
2021-07-09
What The Study Did: Researchers characterized clinical content of ambulatory care among office-based compared with telemedicine visits in the United States before and during the COVID-19 pandemic.
Authors: G. Caleb Alexander, M.D., M.S., of the Johns Hopkins Bloomberg School of Public Health in Baltimore, is the corresponding author.
To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/
(doi:10.1001/jamahealthforum.2021.1529)
Editor's Note: The article includes conflicts of interest disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.
INFORMATION:
Media advisory: The full study is ...
2021-07-09
Primary care clinicians face a heavy administrative burden, spending significantly more time using the electronic health record (EHR) than their counterparts in other specialties. With studies demonstrating high rates of burnout among primary care clinicians, researchers from Brigham and Women's Hospital and collaborators set out to examine how different types of primary care clinicians interface with the EHR. They found that general internal medicine and family medicine clinicians spent an average of two hours actively using the EHR each day, while general pediatric clinicians actively ...
2021-07-09
12,000 people in Denmark and 7 to 10 million people worldwide suffer from Parkinson's Disease (PD). It is the second most common neurogenerative disorder of aging and the most common movement disorder, but the cause of the disease is largely unknown.
In a new study, researchers from the University of Copenhagen show that the most common form of the disease, encompassing 90 to 95 percent of all Parkinson's Disease cases known as sporadic PD, is caused by a blockage of a pathway that regulates the nerve cell's powerhouse, the mitochondria.
'Just like when people eat, cells take what they need and get rid of the rest waste products. But if ...
2021-07-09
It is believed to be involved in the development of chronic inflammatory intestinal diseases, to trigger diabetes, to be responsible for obesity, even neurological diseases such as multiple sclerosis and Parkinson's could have their causes here - not to mention depressions and autistic disorders. We are talking about the microbiome - the vast collection of bacteria in the human gut. It is estimated that each person carries around 100 trillion bacterial cells in their digestive tract, belonging to several thousand species.
The microbiome has been the focus of research for 20 years - ever since a new technique made it possible to analyse these bacteria quickly and precisely: high-throughput sequencing. Since then, there has been an increasing body of findings that ...
LAST 30 PRESS RELEASES:
[Press-News.org] Neonatal meningitis: the immaturity of microbiota and epithelial barriers implicated
