MATERIAL FROM THE LIVING SUBJECT 229 



mycetes in the pus from old cavities in the lungs should be borne in 

 mind. Aetinomyces are usually visible to the naked eye as minute, yel- 

 lowish granules which exhibit the characteristic club when viewed under 

 the microscope in properly stained specimens. Pus from abscesses 

 in the cervical region may contain spiral organisms. The occurrence 

 of these organisms should suggest the possibility of a sinus connecting 

 the abscess with the mouth. Frequently such a sinus originates at 

 the base of a carious tooth. 



Examination of Urine. A bacteriological examination of the 

 urine is of value not only in the diagnosis of infection of the genito- 

 urinary system; it may afford information of the causative organisms 

 in septicemia, and occasionally those concerned in the more chronic 

 heart or joint lesions as well. 



The external genitalia are usually contaminated with B. smegmatis, 

 which resembles the tubercle bacillus, and with various adventitious 

 organisms as well. Prominent among the latter is Bacillus coli. A 

 satisfactory sample of urine for bacteriological examination may be 

 obtained from males if the glans and meatus are thoroughly cleansed 

 with soap and water. The greater amount of urine passed should be 

 rejected, and the last portion should be collected in a sterile, wide- 

 mouthed bottle. It is necessary to catheterize females after a pre- 

 liminary cleansing with soap and water, to obtain a satisfactory 

 specimen for bacteriological examination. A sterile catheter must be 

 used, and the first portion of the urine should be discarded. Under 

 ordinary conditions, except in tubercle infections the causative 

 organisms will be present in sufficient numbers so that a direct smear 

 of the sediment, stained by Gram's method, will furnish a valuable 

 clue to the method and media to be used for the isolation and identifi- 

 cation of the organism. 



Blood agar is a favorable medium for the isolation of the streptococ- 

 cus, pneumococcus, gonococcus and staphylococcus. The gonococcus 

 is usually recognized by a Gram-stained smear without further attempt 

 at isolation. It is a Gram-negative diplococcus which, in acute infec- 

 tion, usually appears both intra- and extracellularly among polymor- 

 phonuclear leukocytes. Micrococcus catarrhalis, which might easily 

 . be confused with the gonococcus, occurs very rarely in genito-urinary 

 infections; ordinarily it may be disregarded. Micrococcus melitensis 

 grows very slowly upon ordinary media. Its very small size together 

 with the deliberateness of growth usually suffice to attract attention 

 to its presence. An agglutination with a specific serum completes the 



