Risk assessment of Allofrancisella frigidaquae

Allofrancisella frigidaquae and the isolate Francisella sp. W12-1076 are Gram-negative, aerobic, non-motile, and catalase-positive bacteria from the family Francisellaceae that were isolated from water reservoirs of cooling systems. A comparison of the whole-genome sequences of Allofrancisella frigidaquae and Francisella sp. W12-1076 showed very high similarity, so the isolate was assigned to the species A. frigidaquae. A. frigidaquae grows in a temperature range of 18 to 37 °C, with the optimum temperature being 30 to 32 °C. Members of the genus Allofrancisella produce β-lactamases and are resistant to chloramphenicol, but sensitive to ciprofloxacin, doxycycline, gentamicin, levofloxacin, and tetracycline. The genome of A. frigidaquae contains two clusters with similarity to the Francisella pathogenicity island (FPI). The FPI is important for the pathogenicity and intracellular growth of Francisella tularensis and contains 15 to 19 open reading frames (ORFs), which encode, among other things, a type VI secretion system (T6SS). In addition, the genome of A. frigidaquae contains other genes for putative virulence factors, such as chitinases, which are relevant for the pathogenicity of Legionella spp. in mice. A. frigidaquae persists in the human macrophage cell line U937, human alveolar epithelial cells, the mouse macrophage cell line J774A.1, and the amoeba Acanthamoeba lenticulata, but is unable to replicate in these cells. The bacterium is assigned to risk group 1 in TRBA 466 "Classification of Prokaryotes (Bacteria and Archaea)". The ZKBS assigns Allofrancisella frigidaquae (Francisella sp. W12-1067) to risk group 2 as a donor and recipient organism for genetic engineering work in accordance with Section 5 (1) of the GenTSV in conjunction with the criteria in Annex 1 of the GenTSV , as the bacterium is related to bacterial pathogens of animals and humans and persists intracellularly in established cell lines and amoebae. The genome contains genes similar to virulence and fitness factors of pathogenic bacteria. Therefore, the pathogenicity of A. frigidaquae cannot be ruled out. The ZKBS statement can be accessed under the reference number 45241.0222 .