Important: New recommendations for risk assessments by the ZKBS (III)

Most recently, in its statement from May 2019, the ZKBS also classified Mycolicibacterium neoaurum, Thermothelomyces thermophilus and Thermothelomyces thermophilus HC as well as production strains derived from them.

1. Mycolicibacterium neoaurum (M. neoaurum) is known to cause human pathogens. Diseases it causes include bacteremia, wound, respiratory, and skin infections, and endocarditis after heart valve transplantation, which often occur in immunocompromised patients. M. neoaurum is treatable with a variety of antibiotics, although it exhibits clarithromycin resistance.

According to the TRBA, the bacterium is already classified as Risk Group 2. The ZKBS supports this assessment and justifies this by stating that M. neoaurum causes diseases in humans, but only rarely. The ZKBS's full statement can be found here.

2. Thermothelomyces thermophilus The fungus under consideration is characterized by a high tolerance range to the prevailing temperature and can be found worldwide.

A total of twelve cases of disease in humans, some of which were fatal, are known to have been attributable to T. thermophilus. Two immunosuppressed patients and one female patient died after surgery. The fungus has already been classified in Risk Group 1 according to TRBA 460. The ZKBS does not follow this classification, but classifies Thermothelomyces thermophilus as a donor and recipient organism for genetic engineering work in Risk Group 2. The reason for this higher classification is that the pathogen can also cause disease in immunocompetent individuals.

In addition, the ZKBS classifies production strains derived from the Thermothelomyces thermophilus HC strain as Risk Group 1. This is based on the fact that these substances have been used in industrial production for a long time without any known infections among workers. Furthermore, an animal study on mice suggests that the strains derived from Thermothelomyces thermophilus HC are non-pathogenic.