140 CLINICAL BACTERIOLOGY AND HEMATOLOGY 



They cannot be distinguished from B. coli except by rather 

 comphcated cultural tests, or, less certainly, by means of the 

 agglutination reaction. In cases where they are suspected the 

 urine must be plated out on gelatin, and several small greyish, 

 semi-transparent, non-liquefying colonies picked out with a straight 

 platinum wire and each transplanted to a fresh agar tube. After 

 twelve to eighteen hours' incubation there should be a delicate 

 greyish growth, with a shght tendency to spread from the line of 

 inoculation. This is to be tested by performing Widal's reaction 

 with it, using the blood from a patient who is suffering or has 

 suffered from typhoid fever, and whose blood is known to give a 

 Widal's reaction in a high dilution — say, i in 200. If the blood 

 clumps the culture you have obtained from the urine when used 

 in the same dilution, the organism is almost certainly the typhoid 

 bacillus. 



The importance of this examination is that the typhoid bacillus 

 may be excreted in the urine for years after an attack of typhoid 

 fever, causing no symptoms, but remaining a very potent cause of 

 infection. Since this is a source of such danger to others it is 

 advisable to make use of the services of an expert (who will use 

 better methods than that described) in the examination of a 

 suspected case. The escape of the bacilli may sometimes be 

 stopped by the administration of urotropin. 



Bacteriuria, or Bacilluria, is a term which should be 

 restricted to the escape of bacteria in the urine without the 

 presence of pus and without clinical evidence of cystitis, pyelitis, 

 etc. B. coli is the most common organism causing this condition. 



The disease may be diagnosed when a urine which contains 

 numerous bacteria is found on several occasions to be free 

 from pus. 



THE COLLECTION OF FLUIDS FROM SEROUS 

 CAVITIES 



A bacteriological examination of the inflammatory exudates 

 which collect in the various cavities of the body often yields 

 important information as to the nature of the morbid process 

 suggests treatment, and influences our views as to the prognosis 

 of the condition. This is especially the case with the fluids which 

 collect in the pleura, the membranes of the brain and cord, and 

 the joints. In some cases all the needful information may be 



