University
of Texas Medical Branch at Galveston
Researchers
from The University of Texas Medical Branch at Galveston have developed a
vaccine against salmonella poisoning designed to be taken by mouth. The
findings are detailed in an article published in Frontiers in Cellular
and Infection Microbiology.
In
earlier studies, the UTMB researchers developed potential vaccines from three
genetically mutated versions of the salmonella bacteria, that is Salmonella
Typhimurium, that were shown to protect mice against a lethal dose of
salmonella. In these studies, the vaccines were given as an injection.
However,
oral vaccination is simplest and least invasive way to protect people against
salmonella infection. Taking this vaccine by mouth also has the added advantage
of using the same pathway that salmonella uses to wreak havoc on the digestive
system.
"In the current study, we analyzed the immune responses of mice that received the vaccination by mouth as well as how they responded to a lethal dose of salmonella, said Ashok Chopra, UTMB professor of microbiology and immunology.
"We
found that the orally administered vaccines produced strong immunity against
salmonella, showing their potential for future use in people."
There
is no vaccine currently available for salmonella poisoning. Antibiotics are the
first choice in treating salmonella infections, but the fact that some strains
of salmonella are quickly developing antibiotic resistance is a serious
concern.
Another
dangerous aspect of salmonella is that it can be used as a bioweapon -- this
happened in Oregon when a religious cult intentionally contaminated restaurant
salad bars and sickened 1,000 people.
Salmonella
is responsible for one of the most common food-borne illnesses in the world. In
the US alone, the Centers for Disease Control and Prevention estimates that
there are about 1.4 million cases with 15,000 hospitalizations and 400 deaths
each year.
It
is thought that for every reported case, there are approximately 39 undiagnosed
infections. Overall, the number of salmonella cases in the US has not changed
since 1996.
Salmonella
infection in people with compromised immune systems and children under the age
of three are at increased risk of invasive non-typhoidal salmonellosis, which
causes systemic infection.
There
are about one million cases globally per year, with a 25 percent fatality rate.