fbpx
Sign up now!
Don't show this again
Sweepstakes Rules

We’re glad you’re enjoying Poultry Health Today.
Access is free but you’ll need to register to view more content.
Already registered? Sign In
Tap to download the app
X
Share
X
REPORTSCollect articles and features into your own report to read later, print or share with others

Create a New Report

Favorites

Read Later

Create a new report

Report title (required) Brief description (optional)
CREATE
X
NEXT
POULTRY PORK FISH
follow us


You must be logged in to edit your profile.

Favorites Read Later My Reports PHT Special Reports
Poultry Health Today is equipped with some amazing (and free) tools for organizing and sharing content, as well as creating your own magazines and special reports. To access them, please register today.
Sponsored by Zoetis

Sponsored By Zoetis

.

Study shows modified-live vaccine can aid fight against Salmonella Infantis

website builder New research shows that using a modified-live Salmonella Typhimurium (ST) vaccine helps protect broilers against Salmonella Infantis, the most commonly-isolated serotype in chicken parts and comminuted chicken over the last few years1, and one which can cause salmonellosis in people. However, vaccination alone is not enough to alleviate risk.

“The big driving force for us to do the study was to look at whether we would get good cross-protection with the vaccine against a group C serotype, Salmonella Infantis, that’s an emerging cause of human foodborne illness,” said Charles Hofacre, DVM, PhD, of Southern Poultry Research Group Inc. and one of the authors of the research.

Staged challenge study provides insight

The work, published in the Journal of Applied Poultry Research, began by establishing the optimum dose of S. Infantis to assess internal colonization of broilers at processing age. The researchers concluded that 108 was the ideal for use in this context, with 106 failing to colonize and 109 overwhelming birds.

Then, in a challenge study, three pen experiments were set up. The first two, using 64 birds each, compared the effects of different levels of direct challenge with an S. Infantis field strain on vaccinated and unvaccinated birds. The third explored horizontal — bird to bird — challenge using “seeder” birds inoculated with the pathogen and a total of 1,200 chicks to assess the impact of ST vaccination, which was done at day 1 and day 14 for all birds vaccinated.

At the end of the experiments, the researchers obtained liver and spleen samples, which were pooled, as well as cecas, while in the third part of the study, they also determined the presence of the pathogen on feathers using techniques similar to a carcass rinse.

Salmonella colonization of organs reduced

The researchers found that S. Infantis colonization was significantly reduced in both incidence and load in the liver and spleen of vaccinated compared to unvaccinated birds at processing, but no significant difference in the level of the pathogen was observed in ceca or on feathers upon rinse. Horizonal challenge resulted in lower colonization overall. Over the course of the work, the vaccine had no effect on bodyweight gain, feed intake or feed conversion.

“Internal organs are often the source for Salmonella in ground chicken products that could potentially be a food source of a foodborne outbreak,” Hofacre explained.

“The lower colonization we saw tells us that it’s working — [the vaccine] is keeping it from getting into the internal organs. If we use the live vaccine plus another intervention, we might get that significant reduction in the ceca.”

Multiple measures needed

There is no “silver bullet” for controlling Salmonella in broilers, he cautioned, and a “multi-hurdle” approach generally brings the best results. Additional measures on top of vaccination include the use of medium-chain fatty acids in birds’ drinking water or feed, as well as direct-fed microbials.

Each step can contribute to an improved picture for affected flocks, he stressed, while further research could explore which of these complementary approaches yields the best results.

“It would be really nice to be able to say, ‘okay, if I use, for example, this particular organic acid, or this botanical product, at this level, along with the vaccine, I get that significant reduction,’” he added.

 

 


1 Pulido-Landinez M. Salmonella Infantis biomapping in broiler chicken farms and processing plant: Identification and persistence of an emerging serotype in a broiler vertical integration. International Poultry Scientific Forum. 2018, 12.

Share It
New research shows that using a modified-live Salmonella Typhimurium (ST) vaccine helps protect broilers against Salmonella Infantiswhich can cause salmonellosis in people. However, vaccination alone is not enough to alleviate risk.

Click an icon to share this information with your industry contacts.



Posted on March 28, 2022

tags: ,
RELATED NEWS



You must be logged in to edit your profile.

Google Translate is provided on this website as a reference tool. However, Poultry Health Today and its sponsor and affiliates do not guarantee in any way the accuracy of the translated content and are not responsible for any event resulting from the use of the translation provided by Google. By choosing a language other than English from the Google Translate menu, the user agrees to withhold all liability and/or damage that may occur to the user by depending on or using the translation by Google.