Hemolytic activity reevaluation of putative nonpathogenic Listeria monocytogenes strains.

  • Roy Lachica
  • Published 1996 in Applied and environmental microbiology


Identification of 12 strains originally characterized as nonpathogenic Listeria monocytogenes was reassured following the evaluation of their hemolytic capability with a newly developed horse blood agar plate. Seven of the strains were observed consistently to be hemolytic and confirmed as L. monocytogenes with the use of two commercial systems: the Gene-Trak L. monocytogenes-specific colorimetric DNA hybridization assay and the API Listeria system. Except for one strain that formed typical smooth colonies, these hemolytic strains formed rough colonies on a selective medium, lithium chloride-ceftazidime agar. The rest of the strains were nonhemolytic and did not hybridize with the DNA probe; they were identified as Listeria innocua on the basis of their API Listeria system biochemical profile. All but one of these nonhemolytic strains formed smooth colonies on lithium chloride-ceftazidime agar.

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Cite this paper

@article{Lachica1996HemolyticAR, title={Hemolytic activity reevaluation of putative nonpathogenic Listeria monocytogenes strains.}, author={Roy Lachica}, journal={Applied and environmental microbiology}, year={1996}, volume={62 11}, pages={4293-5} }