Two separate species of Aeromonas, A. sobria (not listed as a species in Bergey's Manual of Determinative Bacteriology, 8th ed.) and A. hydrophila, were primary pathogens isolated from the leg wound of a diver conducting operations in polluted waters. This is the first recorded instance of a primary infection of soft tissue in a human caused by two species of Aeromonas, one of which was resistant to tetracycline. Because of the very rapid development of this wound infection, cytotoxicity of these organisms was examined in several biological systems. A. sobria was hemolytic for sheep erythrocytes, cytotoxic for Y-1 adrenal cells, and enterotoxic in rabbit ligated intestinal loops, whereas A. hydrophila was hemolytic and cytotoxic. Pertinent clinical, bacteriological, and environmental features of the case are presented.

During a survey for the presence of Aeromonas salmonicida, 45 Aeromonas isolates which could not be classified in the existing namied species of the genus were recovered from water obtained from the River Avon in Hampshire, England. On the basis of a numerical taxonomy study, these isolates were clustered in three homogeneous phena. Phenon 1 was identified as a new species of Aeromonas, for which we propose the name Aeromonas media; strain RM (= ATCC 33907) is the type strain of this species.

Counts of total viable, aerobic, heterotrophic bacteria, indicator organisms, and Aeromonas spp. were made at a diver training site on the Anacostia River in Washington, D.C. The numbers of Aeromonas cells in Anacostia River sediment and water increased during periods of elevated water temperature, to maxima of 4 x 105 cells per g of sediment and 300 cells per ml of water. Correspondingly,

Phenetic data on over 600 aerobic, heterotrophic, aquatic bacteria from a freshwater fish farm were collected and examined by numerical taxonomy procedures using 124 unit characters. Reference cultures representing 36 taxa were included in the analyses. The data were examined using the simple matching (SsM) and Jaccard (S,) coefficients, and clustering was achieved using unweighted average linkage. At similarity values of 70% or above as defined with the S, coefficient, 82% of the environmental isolates were recovered in 14 major and 56 minor phena. The major phena were equated with Acinetobacter calcoaceticus, Aeromonas hydrophila,

No abstract