How common is Listeria monocytogenes in France

07.10.2019 17:21

Highly virulent listeriosis pathogens discovered

Caroline Link Department for press and public relations
Justus-Liebig university of Giessen

International research team identifies the genetic basis for the hypervirulence of a Listeria strain - work at the JLU funded by the EU and supported by the German Center for Infection Research (DZIF)

The bacterium Listeria monocytogenes can cause life-threatening infections; common sources of infection are contaminated food. Elderly people, people with a weakened immune system and pregnant women, of whom up to 30 percent do not survive an infection with Listeria, are particularly at risk. An international research group headed by the Institute for Medical Microbiology at the Justus Liebig University in Giessen (JLU) has now discovered the most virulent representatives of this bacterial species to date. They have been identified as the cause of serious illnesses in sheep in a remote area in the Chinese province of Jiangsu - animals can also become infected with listeriosis.

"The detection of a completely new form of pathogenic Listeria monocytogenes in China underlines the need for international cooperation in order to quickly identify not only multi-resistant bacteria, but also emerging threats to food safety from highly virulent strains worldwide," emphasizes Prof. Dr. Trinad Chakraborty, Director of the Institute for Medical Microbiology at JLU and scientist at the German Center for Infection Research (DZIF).

The scientists deciphered the genome sequence of these bacteria and were able to determine the genetic basis for their hypervirulence. They identified the bacterial factors that enhance the ability of this strain of Listeria to cause serious septic disease. "These isolates are unique in that they combine the virulence characteristics of various highly pathogenic Listeria species that infect either animals and / or humans in a single strain," says Prof. Chakraborty. "Since listeriosis is a food-borne infection, measures to identify such highly virulent strains are of great urgency."

Clinical symptoms of listeriosis are fever, blood poisoning (sepsis) and infections of the central nervous system, which can lead to lifelong sequelae. Infections during pregnancy can lead to premature births, miscarriages, or stillbirths. Both raw and processed foods can be contaminated by Listeria - especially dairy products, meat, seafood and ready-to-eat products such as packaged mixed salads. Because of the dangerous nature of human listeriosis, many countries have put surveillance systems in place to quickly identify and recall contaminated food products. Since it can take up to 70 days for Listeria infection to show up with severe symptoms, it can be difficult to identify the source of the contamination and initiate the food recall.

There are currently outbreaks of listeriosis in Germany (Hesse), the Netherlands, Lithuania, Spain, Great Britain, Canada and the United States, which primarily threaten the most vulnerable groups of the population. Therefore, considerable efforts are now being made to identify the origin of these pathogens and thus prevent further outbreaks of listeriosis.

Researchers from the State Key Laboratory of Zoonosis at the University of Yangzhou in Jiangsu (China) and the Laboratory for Food Microbiology at the Swiss Federal Institute of Technology (ETH) were involved in the study published in the journal "Nature Communications" on the highly virulent Listeria strain isolated in China ) Zurich (Switzerland) and the Institute for Medical Microbiology at JLU. The work at the JLU was funded by the EU program ERA-NET PROANTILIS. The study was also supported by the German Center for Infection Research (DZIF).

Scientific contact:

Prof. Dr. Trinad Chakraborty
Institute for Medical Microbiology at JLU
Phone: 0641 99-41250

Original publication:

A hybrid sub-lineage of Listeria monocytogenes comprising hypervirulent isolates; Nat. Comm. 2019, DOI: 10.1038 / s41467-019-12072-1

Additional Information:

Features of this press release:
Biology, medicine
research results