Colloidal Silver and Listeria Contaminated Food

Hi, Steve Barwick here, for The Silver Edge

Here's a good reason to ALWAYS have colloidal silver on hand:

Even the best organic fruits, veggies, nuts, beans and other foods can end up being contaminated with potentially deadly microbes, resulting in horrific cases of food poisoning.

In one particular recent case, certain organic fruits and veggies have been recalled nationwide by the FDA due to contamination with the potentially deadly food-poisoning pathogen known as Listeria monocytogenes.

You can read about the latest U.S. food recall in the official FDA public notice at this link, dated May 2, 2016. Or, read the article "Listeria Outbreaks a Growing Threat," at this link for information on the Canadian food recall.

What is Listeria?

According to food safety experts, Listeria is an organism that "can cause serious and sometimes fatal infections in young children, frail or elderly people, and others with weakened immune systems."

Experts at the University of Guelph in Ontario, Canada point out that about one out of every three people infected with Listeria will die from the infection. They write:

"Listeria, known by its scientific name as L. monocytogenes,can be especially deadly. This pathogen is found in soil, vegetation, water, sewage, livestock feed and feces.

It's also found in many foods, including meats, fish, produce and dairy products. Humans and animals can carry listeria without knowing it.

Listeria can survive typical refrigeration temperatures, and does not affect the look, smell or taste of contaminated food.

'When it does hit, it can be very severe and serious,' says food science professor Jeffrey Farber. 'In an outbreak situation, if 100 people are infected, you could expect 30 of those people to die.'"

Colloidal Silver v/s Listeria

But of course, the important question is this: Does colloidal silver kill the Listeria pathogen? You bet it does!

In fact, years ago a company called NVID International Inc., which was doing experiments using small amounts of silver to decontaminate public water systems, confirmed that ionic silver killed Listeria, as well as eight other serious pathogens.

Listeria was among the nine bacteria that were easily killed by ionic silver. Here's the complete list:

  • Listeria monocytogenes ATCC 11543
  • Pseudomonas aeruginosa ATCC 15442
  • Staphylococcus aureus ATCC 6538
  • Salmonella cholerasuis ATCC 10708
  • E.Coli ATCC 0157:H7
  • Enterococcus faecium ATCC 11543
  • Rhinovirus (common colds)
  • Rotavirus (infectious diarrhea)
  • Vancomycin-resistant-enterococci (VRE)

To learn more, here's a short article I wrote years ago titled Ionic Silver Purifies Municipal Drinking Water, explaining how NVID International Inc. discovered the fact that silver kills the Listeria pathogen, as well as eight other potentially deadly pathogens, while testing pathogen levels in municipal drinking water.

And here's a follow-up article I wrote afterwards, titled Colloidal Silver Kills Listeria.

Since the time I wrote the above two articles, much new information on colloidal silver's effectiveness against Listeria has come to light.

For example, Brooks Bradley, a researcher at the Harbone Research Foundation, has also found that colloidal silver kills the Listeria pathogen, among other potentially deadly food-poisoning pathogens. He wrote:

"Several years ago we conducted some rather extensive evaluations of various protocols promising effective results against various pathogenic agents which cause 'food poisoning'.

The one protocol, effective against ALL agents evaluated, was colloidal silver. A 5 ppm solution proved effective against all pathogens tested; yielding complete control within 6 to 8 minutes...regardless of concentration of the pathogenic agent.

Control was effected in some solutions as weak as one part of 5 ppm colloidal silver, to 50,000 parts contaminated solution.

Among the many agents tested were botulinum, campyobacter, salmonella and listeria (bacterial agents); and norwalk-like viruses and hepatitus A (viral agents)."

What's more, according to a clinical study published in the International Food Resource Journal in 2011, titled, "A study on the minimum inhibitory concentration and minimum bactericidal concentration of Nano Colloidal Silver on food-borne pathogens," researchers wrote:

"Nano colloidal silver can be a potential antimicrobial agent due to its low cost of production and high effectiveness in antimicrobial properties, which may find wide applications in various food industries to address food safety issues...

…Ten different concentration of Nano Colloidal Silver were tested against Listeria monocytogenes Escherichia coli O157:H7, Salmonella enterica Serovar Typhi, Vibrio cholerae,Vibrio parahaemolyticus, Bacillus cereus and Staphylococcus aureus…"

The researchers discovered that the Listeria monocytogenes pathogen was inhibited by colloidal silver at 24.58 ppm concentration, while Salmonell typhi and Staphylococcus aureus were inhibited at 23.75 ppm and 13.85 ppm concentrations respectively.

Other pathogens, including E. coli, were inhibited at between 10.63 and 7.71 ppm concentrations of colloidal silver.

The researchers further concluded:

"The antibacterial form of silver is the ions. Minute sub-particles [of nanosilver – ED] continuously emit a sufficient number of positively charged ions.

These destroy the enzymes of the bacteria, destabilize the cell membrane, the cell plasma or the cell wall and prevent their reproduction. The bacteria do not survive this concentrated attack."

The researchers also concluded that "The results…indicated that Nano Colloidal Silver's antibacterial effect is independent of acquisition of resistance by the bacteria against antibiotic drugs and thus be a potential antimicrobial agent to be used."

In other words, the nanosilver worked fabulously even against food poisoning pathogens that have developed resistance to antibiotic drugs.

Finally, in a study titled "Silver as Antibacterial Toward Listeria monocytogenes," published in Frontiers in Microbiology in March 2016, researchers from the Department of Food Safety at the Istituto Zooprofilattico Sperimentale delle Venezie in Legnaro, Italy wrote:

"Listeria monocytogenes is a serious food-borne pathogen that can contaminate food during processing and can grow during food shelf-life.

New types of safe and effective food contact materials embedding antimicrobial agents, like silver, can play an important role in the food industry.

…In this context, the development of new types of safe and effective food contact materials able to extend the shelf life of food products or to prevent cross contamination is of great interest.

Among different chemicals with antimicrobial activity, silver is considered as a good candidate, as it is known to exert antimicrobial properties toward both Gram positive and Gram negative bacteria."

In the study, 20 different strains of Listeria monocytogens were tested. The researchers concluded that the silver was effective against all 20 strains:

"This study aimed to investigate the effectiveness of silver in ionic and nano form as antimicrobial toward a panel of L. monocytogenes isolates.

The results obtained showed that both chemical forms of silver exerted antimicrobial activity and should, therefore, be considered as suitable to be used as biocide against L. monocytogenes.

…The relation between the sensitivity assay and the amount of ions at the tested time points, in both cases (AgNPs and AgNO3) suggests that ions are the more effective elements exerting antibacterial activity.

…Our study suggests that L. monocytogenes is sensitive to silver and that the efficacy is linked to ionic release.

We speculate that silver-based food contact materials could play a useful role in the food industry, perhaps to reduce surface contamination, or eventually, to prolong shelf life."

In short, the researchers urged members of the food processing industry to look into using colloidal silver as an effective biocide against the Listeria monocytogenes food-poisoning pathogen.


Steve Barwick
Steve Barwick

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