As far as I know the strains that have ABP have been isolated from different sources including the environment and food, but I’m not sure if there’s correlation to any of the specific serotypes of Lmo.

However we think that it’s definitely possible that bacteria could have orphan immunities which protect against toxins that they don’t themselves produce, although that doesn’t seem to be the case for these species.

Thanks Filipe! As far as I know neither EGDe or 10403S have an ABP, however other Listeria species definitely do. But you’re right, the immunity proteins are highly specific for each of the variable toxin domains.