A collect~on of 124 isolates of Aeromonas salmonicida ssp. salmonicida from Denmark, Norway, Scotland, and North America was plasmid profiled. All stralns contained at least 1 large plasmid in the range of 60 to 150 kb, and all stralns possessed 2 low-molecular-weight plasmids of 5.2 a n d 5.4 k b Two a d d~t~o n a l low-molecular-weight plasmlds of 5.6 and 6.4 kb were frequently encountered. A total of 23 different plasrnids were demonstrated, 12 of them being found In more than one country. Forty d~fferent plasmld profiles were detected. Seven profiles, representing 75 strains (60 %), were demonstrated in lsolates from more than one country. One profile, w~t h 5 plasmlds of 150, 6.4, 5.6, 5.4, and 5 2 kb, proved to be the most common one among strains from North Amerlca (25 'X), Denmark (33 "%J, and Norway (50 ':h), but ~t proved to be only the third most common one among Scott~sh strains (10 'Z,). Plasmid profiling as an epidemiological t y p~n g method for Aeromonds salmonlclda ssp. salmonlcida was evaluated. The numerical index of discriminatory power (D) was calculated, resulting In a relat~vely high D value of 0.88. However, the results of the present study suggest that plasmid profiling may be of llmited value as an epidemiological marker within Aeromonas salrnonicida ssp. salrnonicida.

Media designed to yield more specific and more sensitive results than Sabouraud agar in the isolation of systemically infective fungi have been described (Kurung, 1942; Thompson, 1945; Littman, et al., 1949; Littman, 1955). In this report experiments are described which compare the qualitative and quantitative efficacy of various media employed for initial isolation of certain fungi. other sputum samples became available, they were added either to a stock or used as obtained.