of the Fishert/ Board for Scotland. 35 



16. Bacteriological Examination of Fresh Peritoneal Fluid — 



CHIEFLY FOR BaCILLUS CoLI. 



Method adopted. — The fish were killed immediately after capture, the 

 ventral aspect of abdomen washed, with sea water in the case of some 

 dealt with at sea, with tap water and sterile water in the case of those 

 caught near the shore by line — boat or rod. Then the abdomen was 

 carefully seared with red-hot cautery, and peritoneal cavity opened by 

 sterile knife and three loopfuls of peritoneal fluid withdrawn by means 

 of sterile platinum wire and used for the inoculation of each tube of 

 the following media : — 



(a) Bile-salt glucose peptone litmus solution in Durham's fer-. 



mentation tubes. 



(b) Digralski and Conradi's medium. 



Twenty-five experiments were made with the following fish : — Six 

 haddocks, 5 whitings, 2 young skates, 2 codlings, 2 cat-fish, 1 dog-fish, 

 3 plaice, and 4 herrings. 



In 19 cases the results were negative. 



In the case of two herrings, one whiting, and one plaice there appeared 

 in the bile-salt medium a very slight trace or discoloration and just a 

 few bubbles of gas. On the Conradi and Digralski medium one of these 

 herring and the whiting gave negative results. From the remaining 

 herring and plaice subcultures were made on various media, but only in 

 the case of the herring were any growths obtained, and from these a 

 strepto-coccus was isolated. It was noted, however, at the time of 

 capture that this herring did not appear to be in a healthy condition. 

 There were several scratches on its sides and patches of scales had been 

 rubbed off. Two of the cases suffered liability to contamination, and are 

 not here considered. 



Although from these few experiments one is scarcely warranted nor 

 justified in coming to the conclusion that the peritoneal fluid in fish is a 

 sterile fluid, yet, from the fact that out of 23 experiments (leaving out 

 two spoiled experiments), only four suggested some suspicion, and from 

 only one of which, an ill-conditioned fish, was a strepto-coccus isolated, 

 the evidence of these experiments points to the probability of the peri- 

 toneal fluid in healthy living fish as being sterile. 



I made a series of observations regarding the time after death when the 

 bacillus coli could be detected in the peritoneal fluid. 



About 30 experiments were made at different periods. The fish were 

 killed, laid out on trays, and kept moist. At short intervals the abdomen 

 was opened with aseptic precautions and suitable media inoculated, 

 incubated, examined, and subcultures made. 



In about five cases the bacillus coli was detected 40 minutes alter 

 death ; in about nine cases, 1 hour after death ; and from 1 1 to 2 hours 

 after death micro-organisms are numerous in the peritoneal fluid. 



17. The Bearing of the Distribution op Bacillus Coli in Fish 

 AND other Lower Animals on Public Health Questions. 



In consideration of the above results, and those of other workers, it is 

 difficult to avoid the conclusion that the coli bacillus, if not a normal 

 inhabitant of the intestinal canal of fish in general — a statement which 

 we readily admit is not yet fully warranted from the above observations 

 — has at least a far wider distribution in fish than was generally antici- 

 pated 



