CHAPTER XII 



Introduction 



THE procedures for laboratory investigation of mycotic disorders arc 

 on the whole, not difficult to master. The methods outlined here arc 

 those which we use in our mycologic laboratory at the New York Hospital 

 and in private practice. They have been proved by experience to be 

 efficient. We realize that one cannot instruct the novice in all the minute 

 details without practical demonstration. The mediums and technic of the 

 mycologist differ somewhat from those of the bacteriologist. Since most 

 lungi grow well at room temperature, a higher temperature is usually un- 

 necessary. Moreover some fungi which grow luxuriantly at room tempera- 

 lure will scarcely develop when incubated at body heat. This effect may 

 be in part due to desiccation of the agar (lack of moisture) as well as to 

 unsuitable temperature. Culture of bacteria requires incubation in an ele- 

 \ ated temperature. For this reason bacterial contamination of fungous cul- 

 tures is rarely seen; although many species of bacteria normally are present 

 in the mouth, scrapings from the tongue on acid dextrose agar incubated at 

 room temperature are singularly and strikingly free from bacterial contami- 

 nation. The chief contaminants are other fungi, such as Penicillium or 

 Scopulariopsis. Elaborate mediums are not required, and except in detailed 

 work and investigation of minute points only a few mediums arc necessary, 

 unless one is attempting to isolate Actinomyces (closely related to bacteria 

 or Blastomyces. In the former case, incubation at body heat and the use of 

 blood for enrichment may be requisite. In addition, some strains grow only 

 under anaerobic conditions. Blastomyces dermatitidis usually requires in- 

 cubation at 37 C, with blood agar for the primary isolation. At other times 

 growth occurs at room temperature. 



Another difference between growth of bacteria and growth of fungi on 

 artificial mediums is partly due to the method of incubation. Whereas 

 bacteria multiply and colonization is detectable after a few hours or within 

 a few days, a comparable status with fungi requires from several days to 



