Navigation Links
Bacterial colonization prior to catching the flu may protect against severe illness
Date:7/10/2014

Many studies have shown that more severe illness and even death are likely to result if you develop a secondary respiratory infection after developing influenza. Now, however, a team of researchers based at The Wistar Institute has determined that if you reverse the order of infection, the bacteria Streptococcus pneumoniae (often called pneumococcus) may actually protect against a bad case of the flu.

The researchers discovered that the bacterial protein pneumolysin, which is described as a bacterial virulence factor, might protect macrophagesa type of immune system cellin the lungs. Their findings, performed in a mouse model of influenza infection, appear in the August issue of the journal Virology, available online now.

"Influenza remains a major killer, and there is a preponderance of evidence, both scientific and historical, to show how secondary bacterial infections can be fatal," said Jan Erikson, Ph.D., professor at The Wistar Institute. "However, pneumococci often colonize the respiratory tract asymptomatically, particularly in children, leading us to consider how pre-colonization would impact a subsequent influenza infection."

"Our studies showed that prior colonization offered a protective effect against severe disease in mice," Erikson said, "and we were able to point to the bacterial virulence factor pneumolysin in mediating this protection."

In their investigations, Erikson and her colleagues found that mice who were colonized by Streptococcus pneumonia ten days prior to exposure to influenza were significantly less likely to develop severe disease or pneumonia than mice who were not colonized by the bacteria. In contrast, disease symptoms were exacerbated in mice that were exposed to the flu prior to a secondary pneumococcal infection.

"Mice that were first exposed to pneumococci exhibited less inflammation in the lungs following influenza infection. Virus infection wasn't blocked but the response to it was changed such that the mice no longer showed signs of illness," Erikson said.

The researchers then went about investigating how this might occur. Using mutant strains of pneumococcus that lacked certain proteins, Erikson and her colleagues were able to single out one bacterial protein, pneumolysin, which was necessary to generate the protective effect of pneumococcus. While the exact mechanisms by which pneumolysin lessens the severity of disease remain unknown, Erikson and her colleagues were able to show how alveolar macrophages were less likely to recruit inflammation-causing immune cells to the lungs. Less inflammation would mean less chances of developing pneumonia, which is a major source of flu deaths, Erikson says.

According to Erikson, her results suggest that one factor contributing to the highly variable response to influenza virus infection and severity of disease observed in humans is the presence of specific respiratory tract microbes. "It remains to be seen what lessons we can learn from pneumococcus in lessening flu infections," Erikson said, "but I would be interested in seeing if we could get the benefit of pneumococcal colonization without the associated risks."


'/>"/>

Contact: Greg Lester
glester@wistar.org
215-898-3943
The Wistar Institute
Source:Eurekalert

Related medicine news :

1. Pharmacy Robots Linked to Bacterial Contamination of Drugs
2. Children with juvenile arthritis have higher rates of bacterial infection
3. University of Minnesota startup to treat challenging bacterial infection
4. Fish Pedicure a Recipe for Bacterial Infection, Researchers Warn
5. Zooming in on bacterial weapons in 3-D
6. Killer stainless steel: New process gives icon of cleanliness antibacterial coating
7. Study Ties Kids Allergy Risks to Antibacterials, Preservatives
8. Bacterial Vaginosis Increases Female-to-Male HIV Transmission Risk
9. New mechanism of bacterial pathogenesis discovered
10. AuCoin gets $600,000 to refine new test for deadly bacterial infection melioidosis
11. NIH uses genome sequencing to help quell bacterial outbreak in Clinical Center
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/19/2017)... ... January 19, 2017 , ... Wells ... facility enhancement of their 503A compounding pharmacy located in Ocala, Florida. , ... physicians and patients throughout the United States for high-quality human anti-aging and ...
(Date:1/19/2017)... ... January 19, 2017 , ... This month, the CEO and Clinical Director ... their drug rehab center in Delray Beach, Florida has been changed from Sober Living ... such as Philip Seymour Hoffman and Chris Farley are dying from heroin overdoses, but ...
(Date:1/19/2017)... ... 2017 , ... WhoHaha , a digital media company dedicated to creating ... to produce a three-part video series that uses humor to highlight ways to improve ... of AHA’s Healthy For Good™ movement, which is designed to inspire all Americans to ...
(Date:1/19/2017)... ... January 19, 2017 , ... Cosmetic Town, an online plastic surgery community, begins ... make it easier for their readers to get the information they desire. The procedures ... as the techniques used on those particular areas. , “We are excited to streamline ...
(Date:1/19/2017)... ... January 19, 2017 , ... Catalent ... for drugs, biologics and consumer health products, today announced that it will be ... leader in innovative excipients and drug delivery solutions to health industries worldwide. The ...
Breaking Medicine News(10 mins):
(Date:1/19/2017)... 19, 2017 Pfizer joins ... Milner Therapeutics Consortium   Major research ... Cambridge   The Milner Therapeutics ... ) as a partner to the Milner Therapeutics Consortium. ... the efficient transfer of materials between industry and academia ...
(Date:1/19/2017)... 2017  ViewRay, Inc. (Nasdaq: VRAY ... clinical MRI-guided radiation therapy system, announced today that it ... million through a private placement of its common ... financing and was joined by certain of ViewRay,s ... Venture Partners, and an additional new institutional investor, ...
(Date:1/19/2017)... , Jan. 18, 2017 The ... Food and Drug Administration (FDA) for its release ... and population health decision makers can proactively share ... products as well as emerging therapies awaiting FDA ... mirrors consensus recommendations that AMCP developed during two ...
Breaking Medicine Technology: