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:12/7/2016)... ... December 07, 2016 , ... ... now promoting to the US market its advanced highly customizable contact technology solutions. ... ODU TURNTAC®. These advanced technologies are ideal for a wide range of applications ...
(Date:12/7/2016)... ... December 07, 2016 , ... Baciocco Brothers Insurance ... residents in the Sacramento/Folsom region, is initiating a charity event to raise support ... Choice Another Chance treatment center in Sacramento works to provide area teens and ...
(Date:12/7/2016)... ... ... One of two inventors from Glen Burnie, Md., has a granddaughter who ... is why the co-inventor and I have designed a new and better way to ... of the patent-pending AV-AIR, a device that serves as an alternative to conventional methods ...
(Date:12/7/2016)... (PRWEB) , ... December 07, 2016 , ... A. Kevin ... owners and families throughout the Five Boroughs, is launching a charity drive to raise ... to continue the traditions and spirit of marines and Navy FMF Corpsmen. Working closely ...
(Date:12/7/2016)... ... December 07, 2016 , ... Sharon Kleyne, host of the ... and Your Health on Voice of America, declared on her radio program in November ... the fact that when these bullies attack leaders in corporate America, they are trying ...
Breaking Medicine News(10 mins):
(Date:12/7/2016)... 2016  Palatin Technologies, Inc. ("Palatin") (NYSE MKT: ... previously disclosed underwritten public offering of units with ... sole book-running manager, Roth Capital Partners acted as ... co-manager for the offering. "This financing ... proceeds, allowing us to continue advancing bremelanotide for ...
(Date:12/7/2016)... Md. , Dec. 7, 2016  Northwest ... or the "Company"), a biotechnology company developing DCVax® ... announced that the Nasdaq Staff has not accepted ... of Listing Rules previously reported, and the Company ... withdraw the Company,s common stock from listing on ...
(Date:12/7/2016)... , December 7, 2016 ... Trial Management System (CTMS) Market, by Components (Software, ... Site), End-users (Pharmaceutical and Biotechnology Companies, Clinical Research ... Share, Size and Forecast to 2022", published by ... system (CTMS) market is expected to grow at ...
Breaking Medicine Technology: