A recent research project has discovered a new species of Listeria. The findings have been published in the peer-reviewed journal International Journal of Systematic and Evolutionary Microbiology.

During a microbial assessment of cow milk cheese products in Nigeria, researchers detected a Listeria isolate that could not be assigned to any known species. The researchers compared whole genome sequencing analyses of the 26 known Listeria species against the isolate, which confirmed that the isolate does not belong to any known taxon of the genus Listeria. 

The new species of Listeria is most closely related to Listeria costaricensis. However, the new strain differs from L. costaricensis in that it does not have the ability to ferment sucrose, L-frucose, and starch.

Due to the absence of haemolysis and Listeria pathogenic islands, the researchers believe that the novel species is not pathogenic for humans and animals. The researchers propose Listeria ilorinensis sp. nov. as the name for the novel strain.