Occurrence of a large plasmid in a strain of Plesiomonas shigelloides with cross-reactivity against Shigella sonnei.

The plasmid profile of P. shigelloides SVC 01, strain with cross-reactivity with Sh. sonnei, (obtained from Dr Alf Lindberg, Stockholm University, Sweden), was assayed and compared with other local isolates of Plesiomonas spp. and also with Sh. sonnei. Diversity in occurrence of plasmids among different strains of P. shigelloides were observed. Further, the SVC 01 strain and Sh. sonnei differ in their plasmid profile.

Action of sorbic acid on Staphylococcus metabolism: a microcalorimetric investigation.

Effect of sorbic acid, an antimicrobial food preservative, on the cellular metabolism of Staphylococcus aureus was observed microcalorimetrically. The highly reproducible and characteristic thermograms of the microorganism were affected significantly by the preservative in a concentration dependent manner. Both the peak heat and total heat dissipation profiles were affected by 50% at the maximum permitted concentration (0.2%) for use in foods.