New risk assessments of bacteria in the human microflora

The genus Corynebacterium encompasses Gram-positive, predominantly facultatively anaerobic, non-motile, rod-shaped bacterial species that occur in the environment and on vertebrates, including humans, and are often described as animal or human pathogens. The current ZKBS statement now assesses the risk of three species of Corynebacteria.

Corynebacterium accolens is a part of the human Microflora and is found on the skin and mucous membranes of healthy people. However, there are also reports of infections with C. accolens in both immune-healthy and immunocompromised individuals. The infections were accompanied by abscess formation, pneumonia, or Endocarditis associated with. C. accolens is also regularly used as a pathogen for postoperative Wound infections identified. The virulence mechanisms of C. accolens have not yet been determined.

Corynebacterium propinquum is also part of the human microflora and colonizes the skin and mucous membranes of the respiratory tract of healthy people. Isolated reports describe infections with C. propinquum in immune-healthy and immunocompromised people. These infections occurred, among others, in patients with urethritis, endocarditis or pneumonia The virulence mechanisms of C. propinquum have not yet been conclusively elucidated. However, the bacterium possesses similar virulence factors to various pathogenic Helicobacter, Klebsiella, and Mycobacterium species.

Also Corynebacterium tuberculostearicum is part of the human microflora and is found on the skin and mucous membranes of healthy people. The bacterium has also occasionally been isolated as a contaminant in food. There have already been reports of an association of infection with C. tuberculostearicum and various diseases in both immune-healthy and immunocompromised individuals. These include wound infections after surgical interventions, osteomyelitis after trauma, and the formation of ulcers and abscesses. C. tuberculostearicum could the exact Virulence mechanisms have not yet been identified.

In the Technical Rules for Biological Agents 466 “Classification of Prokaryotes (Bacteria and Archaea)”, *C. accolens, C. propinquum and C. tuberculostearicum * are classified in the Risk group 2 classified

The ZKBS assigns C. accolens, C. propinquum and C. tuberculostearicum According to Section 5 Paragraph 1 of the Genetic Engineering Ordinance (GenTSV) in conjunction with the criteria in Annex 1 of the Genetic Engineering Ordinance (GenTSV), donor and recipient organisms for genetic engineering work are classified as risk group 2. Bacterial species from the normal human microflora can, if they overcome the skin or mucous membrane barrier, trigger diseases even in people with healthy immune systems, although these diseases are generally easy to treat.

The complete ZKBS statement can be found at File number 45241.0252 can be retrieved.