DEHYDRATED CULTURE MEDIA 117 



practical for use in all laboratories. Furthermore, cultural methods have been 

 designed to check the response of the gonococcus to chemotherapeutic agents, 

 thereby enabling the clinician to select more effectively the materials used in 

 treating gonococcal infections. 



Interest in the cultural procedure for the diagnosis of gonococcal infections 

 was stimulated by Ruys and Jens,^ McLeod and co-workers,^ Thompson,* Leahy 

 and Carpenter,^ Carpenter, Leahy and Wilson^ and Carpenter,''^ who clearly 

 demonstrated the superiority of this method over the microscopic technique. The 

 procedure introduced by McLeod and associates with slight modifications offered 

 itself most advantageously to practical usage for the detection and isolation of 

 A^. gonorrhoeae. 



Lack of a simple, readily available and easily prepared culture medium re- 

 tarded immediate and widespread acceptance of this new technique. In coopera- 

 tion with Dr. Carpenter, and availing ourselves of suggestions received from Drs. 

 McLeod and Herrold, we devoted considerable effort to the development of a 

 culture medium suitable for isolation of the gonococcus from urethral and 

 cervical exudates. The development of this medium was premised upon the 

 stipulations that it must possess a high degree of efficiency, readily lend itself to 

 practical use, be of relatively simple composition and that it be duplicable with 

 ease. 



During our experimental work several media were developed which supported 

 luxuriant growth of the gonococcus in pure culture, but which were unsatisfac- 

 tory with mixed cultures, since other organisms outgrew the gonococcus. In 

 diagnostic work the medium must support the growth of the gonococcus not 

 only when in pure culture, but also permit its development from the mixed 

 flora encountered in chronic gonococcal infections. 



A Chocolate Agar, prepared with Bacto-Proteose No. 3 Agar and Bacto- 

 Hemoglobin, was developed and proved to be satisfactory for the isolation of 

 the organism from all types of gonococcal infections. Nearly 3.5 times as many 

 positives were secured with the cultural method as were obtained by the usual 

 smear technique. In a number of instances the gonococcus was isolated from 

 treated female cases which had shown five to seven consecutive negative smears. 



Since its introduction in 1938 Bacto-Proteose No. 3 Agar, enriched with 

 Bacto-Hemoglobin, has become the most generally accepted medium employed 

 in the laboratory diagnosis of gonorrhoeal infections by the culture method. Car- 

 penter^ reported that this Difco dehydrated medium was as good as or superior 

 to the Douglas Digest Agar described by McLeod. Pelouze^ suggested the use 

 of Bacto-Proteose No. 3 Agar and Bacto-Hemoglobin for the cultural detection 

 of the gonococcus. Sulkin and Gottlieb^^^ used Bacto-Proteose No. 3 Agar and 

 Bacto-Hemoglobin with success, and emphasized the simplicity of the medium 

 and the ease with which it could be prepared. Sewell, Clarke and Nelson^^ re- 

 ported their findings on 4500 cultures plated upon Bacto-Proteose No. 3 Agar 

 and Bacto-Hemoglobin and claimed excellent results. Sewell, Salchow, and 

 Nelson^2 obtained excellent results with urine sediment and urethral secretions 

 plated upon Bacto-Proteose No. 3 Agar enriched with Bacto-Hemoglobin. Car- 

 penter^^ suggested the use of the Bacto-Proteose No. 3 Agar and Bacto-Hemo- 

 globin for isolation of the gonococcus. 



In an extended effort to increase the growth rate of the gonococcus by enrich- 

 ing the Chocolate Agar with plant and animal fluids and thereby shortening the 

 incubation period, some gonococcal strains were encountered that grew well on 

 such enriched Chocolate Agar and only sparsely or not at all on the unenriched 

 medium. Concurrently with this finding Lankford^* reported similar results and 

 suggested enriching the Chocolate Agar with fresh liver extract. Lankford, Scott, 

 Cox and Cooke^^ extended their studies on the nutritional requirements of the 



