National Reference Laboratory for coagulase-positive Staphylococci incl. Staphylococcus aureus (NRL-Staph)

Staphylococci are non-spore forming, facultative anaerobic, gram-positive bacteria which occur naturally in humans and animals. Coagulase-positive staphylococci are important with regard to food hygiene because of their ability to produce staphylococcal enterotoxins (SEs), referred to as superantigens (SAgs), and enterotoxin-like SAgs (SE-like). The five ‘classical’ toxin types (SE-A to SE-E) are currently considered the most important with regard to food poisoning.

The prerequisites for food poisoning via coagulase-positive staphylococci are that the pathogens have sufficiently multiplied in the food product and that heat-stable enterotoxins have been secreted by the pathogens. The dominant symptoms of a staphylococcal poisoning are vomiting, nausea, diarrhoea and circulatory problems. Ingestion of extremely small amounts of toxin is sufficient to trigger these symptoms.

Focus of work and research at NRL-Staph

The work at the NRL-Staph focuses on questions regarding food safety and food hygiene with respect to SEs present in food. An additional focus of the NRL-Staph is the occurrence of methicillin-resistant Staphylococcus aureus (MRSA (PDF file,80.47 KB)) in livestock and foodstuff and its potential transmission to humans.

Major tasks of the NRL-Staph are developing and validating new detection and typing methods, organizing inter-laboratory proficiency tests, providing reference materials, performing confirmation tests on submitted samples and characterizing bacterial strains.

Furthermore, the NRL-Staph conducts research regarding food hygiene issues concerning staphylococci and potential consumer exposure to MRSA along the food chain. Current research efforts encompass the following topics:

• Development, establishment and validation of  new methods for the detection and identification of staphylococci and SEs in food
• Pheno- and genotypic characterisation of MRSA isolated in the course of epidemiological studies from livestock and food
• Whole genome sequencing of  Staphylococcus strains using NGS for the analysis of phylogenetic relationships and genotypic characterization