Key points are not available for this paper at this time.
The possible mechanism involved in the production of virus-like plaques by P. aeruginosa in HeLa monolayers was investigated by testing the cytopathogenicity of sterile filtrates from the plaque-forming system on fresh HeLa monolayer cultures. The results indicated that two types of toxin were produced. One type designated Y was produced in the absence of serum and could be neutralized by the addition of serum. Conversely, the second type of toxin designated Z required the presence of serum for its production and was not neutralized by the addition of fresh serum. Since bacterial plaques are formed only in the presence of serum, toxin Z is indirectly implicated as the causative factor responsible for plaques in HeLa monolayers.
Coleman et al. (Sun,) studied this question.