BACTERIA IN INFECTIOUS DISEASES. 609 



patients during life and in the diseased kidney removed by surgical 

 operation or post-mortem. And recent researches show that the Ba- 

 cillus coli communis, which is constantly present in the intestine of 

 healthy individuals, is found more frequently than any other micro- 

 organism in the so-called "surgical kidney." 



The most important and comprehensive work upon the bacteriology of 

 pyelonephritis is that of Schmidt and Aschoff, published in Jena in 1893. 

 The authors named give a complete resume of the literature of the subject, 

 and a full report of fourteen cases of pyelonephritis, in which they have 

 made bacteriological investigations. They also report a series of experiments 

 upon rabbits, in which injections of a pure culture of the Bacillus coli com- 

 munis were made into the left ureter, after tying it below the point of in- 

 jection. The ligature was removed after the injection had been made, and 

 the wound in the abdominal wall, which had been made with antiseptic pre- 

 cautions, was closed. Some of the animals so treated died in from twelve 

 hours to four or five days, while others survived and were killed on the sev- 

 enth and ninth day. 



The left kidney, especially in the cases which survived the operation for 

 several days, was found to be two or three times as large as the right and to 

 present all the evidences of parenchymatous inflammation. The pelvis of 

 the kidney contained more or less ammoniacal urine, pus, and bacilli ; the 

 parenchyma gave evidence of diffuse inflammation and contained numerous 

 bacilli. As a rule, a pure culture of the Bacillus coli communis was obtained 

 from the inflamed kidney. 



A similar experiment was made with a species of proteus (vulgaris ?), and 

 with a similar result. The animal died at the end of two days. The left kid- 

 ney was twice as large as the right, the surface of a deep-red color dotted 

 with numerous white spots ; the parenchyma had a striped appearance on 

 section and a greenish color in the vicinity of the pelvis, which contained 

 ammoniacal and bloody urine. A putrefactive odor was given off from the or- 

 gan. Proteus in pure culture was recovered from the interior of the kidnev. 



Some of the earlier observers have described non-liquefying bacteria ob- 

 tained from the bladder in cases of chronic cystitis or of pyelonephritis fol- 

 lowing cystitis, which, according to Schmidt and Aschoff, correspond in 

 morphological and biological characters with Bacillus coli communis, and 

 were no doubt identical with it. They believe that the bacillus described by 

 Clado (1887) under the name of " Bacterie septique," and subsequently found 

 byAlbarran and Halle in forty-seven out of fifty cases ^ of cystitis (fifteen 

 times in pure culture), and called by them "Bacille pyogene," is in fact the 

 Bacillus coli communis. 



Schmidt and Aschoff say that the changes found in the kidneys of rabbits 

 after the injection of Bacillus coli communis into the ligated ureter correspond 

 with those seen in the "surgical kidney" of man. They were surprised at 

 the rapidity with which the bacilli penetrated the urinary tubules. The first 

 changes in the parenchyma of the organ occurred at the end of thirty-six 

 hours, and at the end of five to seven days these changes had reached their 

 extreme development. They evidently depended upon the invasion of the 

 urinary tubules by bacilli. This conclusion corresponds with that reached 

 in previous researches by Albarran, Achard and Renault, and by Krogius. 



No doubt cystitis and ascending pyelonephritis are usually caused by 

 microorganisms introduced through the urethra into a bladder which is ren- 

 dered susceptible to infection by mechanical violence or chemical irritation. 

 The most frequent cause of such local infection is the Bacillus coli communis, 

 which is constantly present in the intestine and upon the external surface in 

 the vicinity of the anus, from whence it may easily be transported to the in- 

 terior of the bladder by catheters, etc. , used by the patients themselves or by 

 their medical attendants. 



