Featured Research

from universities, journals, and other organizations

Sources of infection: Mycobacterium avium infections in pigs, humans and birds in Norway

Date:
February 4, 2010
Source:
Norwegian School of Veterinary Science
Summary:
New research from Norway has shown that Mycobacterium avium does not infect pigs via birds, as previously believed. M. avium can be divided into several subspecies, and the research shows that birds are infected by one particular subspecies, whereas pigs and humans are infected by another. Closely related bacteria were isolated in pigs and humans, which would indicate that pigs and humans are vulnerable to infection from the same sources in their surroundings.

Colonies of M. avium with diversified morphological characteristics.
Credit: Tone Johansen

Through work carried out in connection with her PhD, Tone Bjordal Johansen has shown that Mycobacterium avium does not infect pigs via birds, as previously believed. M. avium can be divided into several subspecies, and the research shows that birds are infected by one particular subspecies, whereas pigs and humans are infected by another. Closely related bacteria were isolated in pigs and humans, which would indicate that pigs and humans are vulnerable to infection from the same sources in their surroundings.

Mycobacterium avium is the cause of tuberculosis in birds. In Norway, this disease no longer occurs in poultry, but is occasionally found in wild birds. This bacterium can also lead to infections in mammals, primarily in pigs and humans. Pigs infected with the bacterium seldom become diseased, but the infection can result in financial loss for farmers because meat from the infected animals has to be destroyed.

In humans, this bacterium can result in three different kinds of illness: pneumonia in patients already prone to lung disease, glandular fever in children or generalised infection in AIDS patients. In Norway, about 100 new cases of such infections occur each year.

The aim of the research study was to carry out a genetic comparison of bacteria isolates from birds, humans and pigs in Norway in order to chart possible paths of infection. Studies from other countries have revealed M. avium in the environment, particularly in conjunction with biofilm (bacteria coating) in water and piping systems. Johansen's study therefore examined the bacteria's ability to form a biofilm, since this is a characteristic that can contribute to the spread of infection.

The results of the study show that birds are not the source of infections in pigs caused by Mycobacterium avium since the isolates from birds were identified as M. avium subsp. avium, while the isolates from pigs, humans and the environment were identified as M. avium subsp. hominissuis.

Humans and pigs were found to be infected with related isolates of M. avium subsp. hominissuis, and related isolates were found in pigs in the same geographic area. Infection via M. avium subsp. hominissuis between pigs and humans cannot be completely ruled out, but it is more likely that the environment is the source of infection in both pigs and humans. The study revealed no connection between the ability to form a biofilm and other characteristics examined in the bacteria.

Tone Bjordal Johansen presented her doctoral thesis on 19th November 2009 at The Norwegian School of Veterinary Science. The thesis is entitled: "Characterisation of isolates of Mycobacterium avium with emphasis on IS elements and biofilm abilities."


Story Source:

The above story is based on materials provided by Norwegian School of Veterinary Science. Note: Materials may be edited for content and length.


Cite This Page:

Norwegian School of Veterinary Science. "Sources of infection: Mycobacterium avium infections in pigs, humans and birds in Norway." ScienceDaily. ScienceDaily, 4 February 2010. <www.sciencedaily.com/releases/2010/02/100203091600.htm>.
Norwegian School of Veterinary Science. (2010, February 4). Sources of infection: Mycobacterium avium infections in pigs, humans and birds in Norway. ScienceDaily. Retrieved April 20, 2014 from www.sciencedaily.com/releases/2010/02/100203091600.htm
Norwegian School of Veterinary Science. "Sources of infection: Mycobacterium avium infections in pigs, humans and birds in Norway." ScienceDaily. www.sciencedaily.com/releases/2010/02/100203091600.htm (accessed April 20, 2014).

Share This



More Health & Medicine News

Sunday, April 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nine-Month-Old Baby Can't Open His Mouth

Nine-Month-Old Baby Can't Open His Mouth

Newsy (Apr. 19, 2014) Nine-month-old Wyatt Scott was born with a rare disorder called congenital trismus, which prevents him from opening his mouth. Video provided by Newsy
Powered by NewsLook.com
'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins