Featured Research

from universities, journals, and other organizations

Why is it so difficult to eradicate salmonella?

Date:
February 3, 2010
Source:
Norwegian School of Veterinary Science
Summary:
Feed contaminated by salmonella bacteria is a familiar and costly problem for the animal feed industry all over the world. Some types of salmonella have succeeded in establishing themselves in feed and fish meal factories and have persisted there for several years because it has proved impossible to eradicate them.

Salmonella forming a biofilm on an agar plate.
Credit: Photo by Nesse & Vestby, National Veterinary Institute

Feed contaminated by salmonella bacteria is a familiar and costly problem for the animal feed industry all over the world. Some types of salmonella have succeeded in establishing themselves in feed and fish meal factories and have persisted there for several years because it has proved impossible to eradicate them.

In her doctoral thesis, Lene Karine Vestby therefore studied why it is so difficult to get rid of salmonella once they have managed to establish themselves in Norwegian feed and fish meal factories. She discovered that salmonella bacteria efficient at forming biofilm (bacteria coating) survived for longer in the factories than those that had a reduced ability to form this coating. The ability to survive in factories therefore appears to be connected with the ability to form a biofilm and it would seem that removing biofilm is a necessary step towards eradicating salmonella from the factories.

In a biofilm, bacteria are well protected by a slime (matrix) which they produce themselves. Vestby has studied the effect of the nine most frequently used disinfectants in the Norwegian animal feed industry and found that the efficiency of the disinfectants is substantially reduced if the salmonella has managed to form a biofilm. The effect of the majority of the disinfectants was then no longer satisfactory, but a product containing 70% ethanol was the most efficient, followed by one called Virkon S.

Cooperative behaviour between bacteria (quorum sensing) is an important factor in the ability to form biofilm. In recent years, so-called furanones have been developed, which are known to inhibit quorum sensing and thereby also the formation and maturation of biofilm. Vestby has shown that a furanone can be a useful tool in the fight against salmonella in factories. The furanone prevented the salmonella bacteria from forming an adequate biofilm and the bacteria were therefore more vulnerable to disinfectants, with the result that the disinfectants worked better.

The matrix produced by the salmonella bacteria in the biofilm consists of many different components, one of which is cellulose. A surprisingly large proportion of salmonella found in Norwegian feed and fish meal factories appeared not to produce cellulose. It has been claimed that cellulose is important for protecting bacteria in a biofilm, but Vestby's laboratory tests have demonstrated that biofilm with or without cellulose respectively afforded the bacteria the same protection against disinfectants. On the other hand, it appeared that cellulose in the biofilm gave the bacteria better protection against dehydration over a period of several months.

MSc Lene Karine Vestby presented her doctoral thesis on 5th November 2009 at The Norwegian School of Veterinary Science. The thesis is entitled: "Biofilm formation by Salmonella from the Norwegian feed industry -- with attention to potential persistence and eradication."


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. "Why is it so difficult to eradicate salmonella?." ScienceDaily. ScienceDaily, 3 February 2010. <www.sciencedaily.com/releases/2010/02/100202103928.htm>.
Norwegian School of Veterinary Science. (2010, February 3). Why is it so difficult to eradicate salmonella?. ScienceDaily. Retrieved September 23, 2014 from www.sciencedaily.com/releases/2010/02/100202103928.htm
Norwegian School of Veterinary Science. "Why is it so difficult to eradicate salmonella?." ScienceDaily. www.sciencedaily.com/releases/2010/02/100202103928.htm (accessed September 23, 2014).

Share This



More Plants & Animals News

Tuesday, September 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Tiger Kills Man at India Zoo

Raw: Tiger Kills Man at India Zoo

AP (Sep. 23, 2014) A white tiger killed a young man who climbed over a fence at the New Delhi zoo and jumped into the animal's enclosure on Tuesday, a spokesman said. (Sept. 23) Video provided by AP
Powered by NewsLook.com
Cat Lovers Flock to Los Angeles

Cat Lovers Flock to Los Angeles

AFP (Sep. 22, 2014) The best funny internet cat videos are honoured at LA's Feline Film Festival. Duration: 00:56 Video provided by AFP
Powered by NewsLook.com
Washed-Up 'Alien Hairballs' Are Actually Algae

Washed-Up 'Alien Hairballs' Are Actually Algae

Newsy (Sep. 22, 2014) Green balls of algae washed up on Sydney, Australia's Dee Why Beach. Video provided by Newsy
Powered by NewsLook.com
Raw: San Diego Zoo Welcomes Cheetah Cubs

Raw: San Diego Zoo Welcomes Cheetah Cubs

AP (Sep. 20, 2014) The San Diego Zoo has welcomed two Cheetah cubs to its Safari Park. The nearly three-week-old female cubs are being hand fed and are receiving around the clock care. (Sept. 20) Video provided by AP
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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