Tuesday, 3 September 2013

Tracking antibiotic-resistant strains of Salmonella from farm to fork.


Fascinating American research, funded by the US army, is now being reported in Britain. The days of British government veterinary cover-ups over animal health are clearly numbered.

From stored samples, new science may well open a window on past scandals. Big money is involved and reform of Defra, the agricultural ministry, now inevitable.

Be sure to read the whole news release here.

Researchers track antibiotic-resistant strains of Salmonella from farm to fork.

By Jeff Mulhollem
August 29, 2013

UNIVERSITY PARK, Pa. -- Continuing research on Salmonella may enable researchers to identify and track strains of antibiotic resistant bacteria as they evolve and spread, according to researchers in Penn State's College of Agricultural Sciences...

...Michael DiMarzio, a doctoral candidate in food science working under the direction of Edward Dudley, associate professor and Casida Development Professor of Food Science, developed a method for identifying and tracking strains of Salmonella enterica serological variant Typhimurium as they evolve and spread.

Every year in the United States, the various strains of Salmonella together are responsible for an estimated 1 million illnesses, 20,000 hospitalizations and 400 deaths at an economic cost exceeding $3 billion...

...CRISPRs are present in many foodborne pathogens. The researchers demonstrated that CRISPR sequences can be used to identify populations of Salmonella with common antibiotic-resistance patterns in both animals and humans.

"Specifically, we were able to use CRISPRs to separate isolates by their propensity for resistance to seven common veterinary and human clinical antibiotics," DiMarzio said. "Our research demonstrates that
CRISPRs are a novel tool for tracing the transmission of antibiotic-resistant Salmonella Typhimurium from farm to fork."

DiMarzio found that several subtypes of Salmonella Typhimurium showed up repeatedly in the frozen collection of Salmonella samples taken from cows, pigs and chickens in Penn State's Animal Diagnostic Laboratory. In this case, researchers looked at 84 unique Salmonella Typhimurium isolates collected from 2008 to 2011.

"We know those strains are widely disbursed, and the thing they have in common is that they have noticeably higher levels of antibiotic resistance," he said. "So we examined clinical samples of Salmonella taken from humans, and it turned out that we see an overlap -- the ones we see in humans are the ones we see a lot in animals. You would expect that, but it is confirmation that our method works."...