Simple assay of calcium dependency for virulent plasmid-bearing clones of Yersinia enterocolitica.
A simplified procedure to detect the calcium dependency of virulent plasmid-bearing strains of Yersinia enterocolitica was developed. A low-calcium, agarose-based medium of brain heat infusion with added magnesium effectively differentiated plasmid-bearing and plasmidless isolates. Further, the expression of calcium dependency in plasmid-bearing strains of Y. enterocolitica as measured by the average colony diameter was proportional to the calcium concentration of the assay.
Bhaduri
S
S
Eastern Regional Research Center, U.S. Department of Agriculture, Philadelphia, Pennsylvania 19118.
Turner-Jones
C
C
Taylor
M M
MM
Lachica
R V
RV
D002118:Calcium / Q000494:pharmacology*; D003470:Culture Media; D010957:Plasmids; D014774:Virulence; D015008:Yersinia enterocolitica / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity
D003470:Culture Media; D002118:Calcium