Some interesting things about this outbreak -
Salmonella Saintpaul (Salmonella ssp) is an uncommon strain for poisoning humans. The FDA and the press have consistently stated that the outbreak originated in Mexico. There has never been a case of Salmonella ssp in Mexico - http://news.xinhuanet.com/english/2008-06/...ent_8407060.htm
There has not been one food item found that has Salmonella ssp for the source to be traced back.
If you look at this map of the cases over the last thirty days they are widely distributed - http://www.healthmap.org/en
, indicating a continental wide contamination. Even with our mass food distribution this does not seem plausible especially for such a rare strain of salmonella.
From my research Salmonella ssp is associated with contaminated water and turkeys, horses and cattle. There was an outbreak on mung bean sprouts in the UK and one thought to be on melons in Australia which sickened people and was tied back to contaminated water, but it is not a common strain to infect humans. The UK case seemed pretty clear cut. The Australian one seemed more like this one as there never was any produce found with Salmonella ssp.
While I have no doubt that the promotion of irradiating food is being seized upon by the FDA due to this outbreak, I wonder if the true source of the outbreak is related to ge vaccines that have the salmonella virus implanted in them. Below is some research I have done on the GE angle.
Use of Genetically Modified Viruses and Genetically Engineered Virus-vector Vaccines: Environmental Effects
Author: Chan, Vivian1
Source: Journal of Toxicology and Environmental Health Part A, Volume 69, Number 21, November 1 2006 , pp. 1971-1977(7)
Publisher: Taylor and Francis Ltd
Despite major therapeutic advances, infectious diseases remain highly problematic. Recent advancements in technology in producing DNA-based vaccines, together with the growing knowledge of the immune system, have provided new insights into the identification of the epitopes needed to target the development of highly targeted vaccines. Genetically modified (GM) viruses and genetically engineered virus-vector vaccines possess significant unpredictability and a number of inherent harmful potential hazards. For all these vaccines, safety assessment concerning unintended and unwanted side effects with regard to targeted vaccinees has always been the main focus. Important questions concerning effects on nontargeted individuals within the same species or other species remain unknown. Horizontal transfer of genes, though lacking supportive experimental or epidemiological investigations, is well established. New hybrid virus progenies resulting from genetic recombination between genetically engineered vaccine viruses and their naturally occurring relatives may possess totally unpredictable characteristics with regard to host preferences and disease-causing potentials. Furthermore, when genetically modified or engineered virus particles break down in the environment, their nuclei acids are released. Appropriate risk management is the key to minimizing any potential risks to humans and environment resulting from the use of these GM vaccines. There is inadequate knowledge to define either the probability of unintended events or the consequences of genetic modifications. The objective of this article is to highlight the limitations in environmental risk assessment and raise awareness of the potential risks involving the use of genetically modified viruses and genetically engineered virus-vector vaccines.
Document Type: Research article
Affiliations: 1: Innovative Therapeutics Group, Centre for Drug Administration, Health Sciences Authority, Singaporehttp://query.nytimes.com/gst/fullpage.html...752C1A965958260
November 2, 1993
Birth Control Vaccine Uses Altered Salmonella Bacteria
Salmonella bacteria have been genetically altered to produce an oral birth control vaccine that primes the immune system to reject sperm before conception, a researcher reported today.
The vaccine causes a harmless, temporary infection in the intestine that triggers antibodies against genetic components of sperm that have been spliced into the bacteria, said the researcher, Dr. Roy Curtiss of Washington University in St. Louis.
Unaltered salmonella bacteria cause food poisoning and diarrhea, Dr. Curtiss said. He is using the harmless genetically engineered forms to produce vaccines against hepatitis B and malaria.
Tests of the contraceptive vaccine have been done only in mice so far. But the results suggest that a single dose of the vaccine might prevent conception for several months or longer, and the effect would be reversible, Dr. Curtiss said.
"The idea now would be you don't get your booster, and within a year or so you can conceive again," he said at a meeting of the Council for the Advancement of Science Writing. A male version might be used to disarm sperm, he suggested.
Dr. Curtiss expressed some concern about potential abuse of the vaccine to secretly sterilize an entire population, but because of the temporary nature of the vaccine, "this is something someone might be able to undo," he said.
The salmonella vaccines might prove especially useful in developing countries and rural areas because they do not require refrigeration and are cheaper to produce than the bottles that would contain them, he said. Infection for 2 Weeks
The human vaccines are produced from salmonella bacteria that have been altered in two ways. Parts of the bacteria that cause disease have been removed, and genetic codes from sperm (or hepatitis B virus or malaria parasites) have been inserted.
These altered bacteria cause an infection lasting perhaps two weeks. The foreign genetic components trick the bacteria into producing proteins normally found only in sperm or hepatitis B virus or malaria parasites, as the case may be. The body then mounts an immune response to whatever proteins have been inserted into the bacteria, bolstering immune defenses against an infection or against sperm.
From foe to friend: Researchers use salmonella as a way to administer vaccines in the body
category: EDUCATION> Science
From foe to friend: Researchers use salmonella as a way to administer vaccines in the bodyThe plate on the left shows the minimal growth of Salmonella enterica. The plate on the right shows enhanced growth with the presence of arabinose, demonstrating an ability to effectively...
TEMPE, Ariz. � Researchers at the Biodesign Institute at Arizona State University have made a major step forward in their work to develop a biologically engineered organism that can effectively deliver an antigen in the body. The researchers report that they have been able to use live salmonella bacterium as the containment/delivery method for an antigen.
The work is a major step forward in development of a new means of biological containment that would be a key component to a new way to deliver vaccines in animals and humans. If fully developed, the new method could be used to administer vaccines to many of those who do not benefit from traditional vaccines because of their cost, because of drug resistance or because of limited effects on children.
Outlined in the paper, "Regulated programmed lysis of recombinant Salmonella in host tissues to release protective antigens and confer biological containment," published on the online version (July 7) of the Proceedings of the National Academy of Sciences, the researchers describe a new, novel and effective means of biological containment for antigen delivery. The method not only effectively delivers the antigen in the body, but does so in a way that does not infect the body with salmonella and does not leave any vaccine cells in the environment.
Wei Kong, a researcher in the Biodesign Institute at Arizona State University, holds plates demonstrating the enhanced growth of Salmonella enterica (on viewer's left) in the presence of arabinose.
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The research team includes scientists formally at Washington University, St. Louis, and Megan Health Inc., St. Louis, who are now at ASU's Biodesign Institute and the School of Life Sciences.
"Our goal is to design, engineer and evaluate a live bacterial (using salmonella) antigen delivery system that would display regulated delayed lysis in vivo after invasion into and colonizing internal lymphoid tissues in an immunized individual," said Roy Curtiss, director of the Center for Infectious Diseases and Vaccinology at the Biodesign Institute and a professor in ASU's School of Life Sciences. Curtiss was part of the research team that made the discovery.
"We wanted to do this in a way so that no disease symptoms due to salmonella would arise, a protective immune response would be induced to the pathogen whose protective antigen was delivered by the vaccine construction (in this case against S. pneumoniae due to an immune response to PspA), and there would be no ability for live bacterial vaccine cells to either persist in vivo or to survive if shed into the environment," Curtiss added.
"The biological containment system we developed is sufficient by itself on conferring attenuation, the inability to cause disease symptoms, and ability to deliver an antigen to induce protective immunity," Curtiss said. "We have high expectations that this delivery system will be safe and effective when administered to animals and humans."
A key to the project, according to Curtiss, is "turning a foe into a friend." That foe is the salmonella bacterium�the leading cause of human food-borne illness and which is currently in the news due to contaminated tomatoes and other food crops. Curtiss' team, through genetic know-how, has developed a variety of ways to tame salmonella in the lab and use it as a delivery vector for vaccines.
"We try to genetically modify the salmonella bacterium to eliminate its harmful effects -- the diarrhea, gut inflammation and fluid secretion -- while keeping the wherewithal to induce immunity against the bacteria causing pneumonia or other infectious diseases," Curtiss said. Several in his research team attack the problem from different angles, with some focusing on weakening salmonella, others boosting the immune response and others optimizing the self-destruct mechanism.
Speaking about the application of a pneumonia antigen, team leader Wei Kong, of the Biodesign Institute, said: "If we tried to use live Streptococcus pneumoniae causing pneumonia for a vaccine, we would obviously kill the patient. The benefit of a live vaccine that uses a weakened form of salmonella, is that the salmonella can be taken up through the intestinal lining and stimulate an immune response by using just a portion of the bacteria causing pneumonia that itself is not deadly."
In experiments, the genetically modified Salmonella enterica bacterium colonizes the lymph tissues of the host and manufactures a protein from the S. pneumoniae bacterium, which then triggers a strong antibody response. Unlike most vaccines that are entirely manufactured by a vaccine company, the attenuated recombinant salmonella vaccine after entry into the immunized individual serves as its own factory to produce (manufacture) the protective antigens (proteins) from the S. pneumoniae pathogen. This ability to cause manufacture in the immunized individual dramatically decreases the cost of such vaccines to make them affordable for use in the developing world, Curtiss said.
An important factor for the research team was to genetically program the S. enterica bacterium to destroy itself so that it is not released into the environment, Curtiss said.
"Biological containment systems are important to address the potential risk posed by any unintentional release of the modified salmonella into the environment," he explained. The salmonella life cycle is balanced to allow enough time to enter the body and build an immune response, while leading to cell death by bursting the cells and preventing the vaccine strain from spreading into the environment.
"The data show that the system we have devised results in cell lysis in the absence of arabinose and clearance of the strain from host tissues," the researchers state in the PNAS article.
"More importantly, our strain was fully capable of delivering a test antigen and inducing a robust immune response comparable to that of a vaccine strain without this containment system, thereby demonstrating that this system has all of the features required for biological containment of a recombinant attenuated salmonella vaccine," they added.
The research was funded by the U.S. Department of Agriculture and the National Institutes of Health.
Roy Curtiss, (480) 727-0445
Wei Kong, (480) 727-9591