PATHOGENIC SPECIES 687 



Dactylaria gallopava has been reported as the cause of encepha- 

 litis in turkey poults in South Carolina and Maryland and in chickens 

 in Australia, Georgia, and Indiana. This fungus has been isolated 

 from samples of sawdust litter from poultry lots, from acid hot 

 springs, from geothermal soils in Wyoming, and from self-heating 

 coal waste piles in Pennsylvania and England (see Tansey and Brock, 

 1978). Dactylaria gallopava is also believed to cause disease in birds 

 other than poultry and has been isolated from a human lung 

 (Weitzman, 1977). Pure cultures of D. gallopava isolated from sites 

 having near-neutral pH values grew well between pH ranges of 3.4 

 and 8.9 (Tansey and Fliermans, unpublished data). The distribution 

 of D. gallopava found in our study and the results of the laboratory 

 study indicate that D. gallopava does not require especially acidic 

 conditions for establishment but does require elevated temperatures. 

 Failure to isolate this readily recognizable fungus from such 

 well-studied thermal habitats as composts, wood-chip piles, sun- 

 heated soils, and self-heated hay suggests that it requires more 

 moisture than most species of thermophilic and therm otolerant fungi 

 or that it requires a more-constant elevated temperature. These 

 parameters deserve further attention in efforts to determine the 

 factors that limit the occurrence of this pathogen. Many other 

 species of thermophilic and thermotolerant fungi grow in media 

 having an extremely high osmotic concentration (Tansey, unpub- 

 lished data); this suggests a relative tolerance to low water potential, 

 which would be expected of organisms that characteristically grow in 

 habitats subject to drying. Similarly, many species of thermophilic 

 fungi can grow, sporulate, and exhibit spore germination under 

 conditions in which temperatures fluctuate diumally between per- 

 missive and nonpermissive (Tansey and Jack, 1977; Jack and Tansey, 

 1977). Dactylaria gallopava has not been tested under these 

 conditions. 



We must consider sample size when we evaluate the significance 

 of results of plating water samples. For each sample, a total of at 

 least 8 ml was plated (1 ml on each of four plates of two mediums). 

 An additional amount was plated for each of 14 samples for which 

 10~^ and 10""^ dilutions were prepared. Five samples were plated 

 one additional time (8 ml each) when initial plates contained too 

 many bacterial colonies to allow reliable counting of fungal colonies. 

 Standards for acceptable levels of zoopathogenic fungi in water 

 intended for various uses are poorly defined (American Public Health 

 Association, 1976). A single spore of Emmonsiella (Histoplasma) 

 capsulata will infect a mouse (Ajello and Runyon, 1953); but a 

 normal human may be exposed to millions of spores of ^. fumigotus 



