Navigation Links
Bacterial colonization prior to catching the flu may protect against severe illness

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
The Wistar Institute

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:
(Date:10/13/2017)... ... October 13, 2017 , ... Lori R. Somekh, founder of the Law ... organization of elder law and special needs planning attorneys. “Membership in ElderCounsel helps our ... a forum to network with elder law attorneys nationwide,” said Somekh. , ...
(Date:10/13/2017)... ... October 13, 2017 , ... The Visiting Nurse Association (VNA) of Somerset ... of specialty vendors and unique items from across the nation, this holiday-themed event will ... services offered by the VNA. The boutique will be open Saturday, November 4 ...
(Date:10/13/2017)... ... ... Yisrayl Hawkins, Pastor and Overseer at The House of Yahweh, has released ... understood books in the Holy Scriptures, Revelation. The Book of Revelation paints a picture ... Many have tossed it off as mere rubbish, but Yisrayl Hawkins says that is ...
(Date:10/13/2017)... ... October 13, 2017 , ... “The Journey: From the Mountains to the Mission ... lost souls in the Philippines. “The Journey: From the Mountains to the Mission Field” ... the Bible. She has taught all ages and currently teaches a class of ladies ...
(Date:10/12/2017)... ... October 12, 2017 , ... CitiDent ... sleep apnea using cutting-edge Oventus O2Vent technology. As many as 18 million ... by frequent cessation in breathing. Oral appliances can offer significant relief to about ...
Breaking Medicine News(10 mins):
(Date:10/12/2017)... SAN DIEGO , Oct. 12, 2017   Divoti ... Medical Alert Jewelry up to the standard of the latest FDA ... (Launched: June 2017). Anyone in need of Medical ID ... Divoti Medical Alert Jewelry are engraved in terms of the ... ...
(Date:10/11/2017)... 11, 2017  Hill-Rom Holdings, Inc. ("Hill-Rom") (NYSE: HRC), ... in Las Piedras, Puerto Rico , ... Following a ... sustained minor structural damage, temporary loss of power and ... been completed, manufacturing operations have resumed, and the company ...
(Date:10/4/2017)... , Oct. 4, 2017  South Korean-based healthcare product ... training aide "cprCUBE" on Kickstarter. The device will educate ... cardiac arrests with better efficiency compared to the dated ... real-time feedback on efficacy of the compression for a ... has a goal to raise $5,000. ...
Breaking Medicine Technology: