Navigation Links
Study suggests new way to prevent recurrent ear infections
Date:10/30/2012

Eliminating bacteria's DNA and boosting antimicrobial proteins that already exist may help prevent middle ear infections from reoccurring. These are the findings from a Nationwide Children's Hospital study that examined how an immune defense protein common in the middle ear interacts with a structure meant to protect a colony of bacteria.

The bacterium nontypeable Haemophilus influenzae (NTHI) causes a wide range of diseases of both the lower and upper airways, including middle ear infection. NTHI, like most other bacteria, can form a biofilm, a robust community of bacteria that allows the bacteria to evade the host's immune system and protects the bacteria from antibiotics and other therapies designed to kill them.

Human beta-defensin-3 is an antimicrobial defense protein expressed in the middle ear of humans and other mammals that kills both Gram-positive and Gram-negative bacteria. Previous research has shown that if expression of beta-defensin is disrupted, the host's ability to control the bacteria in the upper airway is altered and infection worsens.

Investigators in The Research Institute at Nationwide Children's Hospital hypothesized that human beta-defensin-3 might lose its power to kill NTHI if it got caught up within the extracellular DNA that makes up a biofilm's outer layer, thus preventing its contact with bacteria within the biofilm.

"Antimicrobial host defense proteins, like human beta-defensin-3, have been shown to bind to non-host DNA," says Lauren O. Bakaletz, PhD director of the Center for Microbial Pathogenesis "This interaction has an impact on the defense protein's ability to function."

Upon examining their animal model of middle ear infection, Dr. Bakaletz' team found that bacterial DNA and the animal's defense peptides were detected together in biofilms that developed during infection. Also, the defense peptide was predominantly co-localized with the biofilm's extracellular DNA.

When the team exposed the bacteria that cause ear infections to a concentration of human-beta defensin-3 that is typically detected in the a middle ear of a child with active infection, the peptide was able to kill 100 percent of the NTHI, but the killing stopped when extracellular DNA was introduced to the reaction.

"These data support the conclusion that the killing activity of the antimicrobial defense protein was decreased in an NTHI-induced biofilm due to its interaction with eDNA," says Dr. Bakaletz, who is the lead study author and professor of Pediatrics and Otolaryngology at The Ohio State University College of Medicine.

When they removed extracellular DNA from the biofilm, the killing activity of the defense peptide was rescued.

"The ability to restore antimicrobial defense protein activity is encouraging, since biofilms are resistant to most treatments, including traditional antibiotics," says Dr. Bakaletz.

Dr. Bakaletz says this study provides evidence for a new treatment regimen to target biofilms formed by NTHI during middle ear infection. One approach would be to deliver a therapeutic agent that can disrupt bacterial DNA, in conjunction with human beta-defensin-3 to the middle ear of a child with chronic, recurrent infection. Physicians could follow the same pathway used to target the middle ear during ear tube surgery, a common treatment for chronic ear infections.

"This approach would likely bolster the ability of the innate immune system to manage NTHI-induced biofilms, avoiding the need for antibiotics or empowering the use of antibiotics we already have in our arsenal," says Dr. Bakaletz. "Doing so could help diminish the recurrent nature of middle ear infection."


'/>"/>
Contact: Erin Pope
Erin.Pope@NationwideChildrens.org
614-355-0495
Nationwide Children's Hospital
Source:Eurekalert

Related medicine news :

1. Study Suggests Vaccine May Help Kids With Brain Cancer
2. Study reveals how cancer drug causes diabetic-like state
3. Coffee Drinking in Pregnancy Wont Lead to Sleepless Baby: Study
4. Lower GI problems plague many with rheumatoid arthritis, Mayo Clinic study finds
5. Veggies Like Broccoli, Cabbage May Help Fight Breast Cancer: Study
6. No Added Cancer Risk From Hip Replacement Materials: Study
7. Reported Decline in U.S. Pneumonia Deaths May Be False: Study
8. Early Study Finds Some Promise for Lung Cancer Vaccine
9. Narcissists Often Ace Job Interviews, Study Finds
10. Sexual objectification of female artists in music videos exists regardless of race, MU study finds
11. Soy may alleviate hot flashes in menopause, large-scale study finds
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/25/2016)... ... June 25, 2016 , ... Austin residents seeking Mohs surgery services, can ... Surgery and to Dr. Russell Peckham for medical and surgical dermatology. , Dr. Dorsey ... cancer. The selective fellowship in Mohs Micrographic Surgery completed by Dr. Dorsey was under ...
(Date:6/25/2016)... ... 25, 2016 , ... "With 30 hand-drawn hand gesture animations, FCPX users can ... CEO of Pixel Film Studios. , ProHand Cartoon’s package transforms over 1,300 hand-drawn ... X . Simply select a ProHand generator and drag it above media or text ...
(Date:6/25/2016)... ... ... As a lifelong Southern Californian, Dr. Omkar Marathe earned his Bachelors in ... School of Medicine at UCLA. He trained in Internal Medicine at Scripps Green Hospital ... at the UCLA-Olive View-Cedars Sinai program where he had the opportunity to train in ...
(Date:6/25/2016)... ... ... Friday, June 10, Van Mitchell, Secretary of the Maryland Department of Health and Mental ... exemplary accomplishments in worksite health promotion. , The Wellness at Work Awards took place ... BWI Marriott in Linthicum Heights. iHire was one of 42 businesses to receive an ...
(Date:6/24/2016)... ... June 24, 2016 , ... A recent article published ... unfamiliar with. The article goes on to state that individuals are now more comfortable ... less common operations such as calf and cheek reduction. The Los Angeles area medical ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... , June 23, 2016 Research ... MEMS Devices Medical Market Analysis 2016 - Forecast to 2022" ... The report contains up to date financial data ... analysis. Assessment of major trends with potential impact on the ... analysis of market segmentation which comprises of sub markets, regional ...
(Date:6/23/2016)... -- , , , WHEN: , ... , , , LOCATION: , , , Online, with free ... EXPERT PANELISTS:  , , , Frost & Sullivan,s Global Vice President ... Industry Analyst, Divyaa Ravishankar and Unmesh Lal, Program Manager , ... is witnessing an exceptional era. Several new demand spaces, such as ...
(Date:6/23/2016)... N.J. , June 23, 2016  Guerbet announced ... Premier Inc.,s Supplier Horizon Award . ... year, Guerbet was recognized for its support of Premier ... creation through clinical excellence, and commitment to lower costs. ... to receive this recognition of our outstanding customer service ...
Breaking Medicine Technology: