4 BULLETIN 51, U. S. DEPARTMENT OF AGRICULTURE. 



cent of the .yolks examined there were no organisms present in 1 cc 

 of the material, and the white of the egg was sterile in 1 cc quanti- 

 ties in 32.18 per cent of the samples examined. Maurer^ reported 

 S1.9 per cent of the eggs he examined to be sterile, and stated that 

 of the 18.1 per cent infected 82 per cent were infected in the yolk, 

 25.9 in the white, and only 7.9 per cent in both yolk and white. 

 Maiirer used aseptic precautions in obtaining samples of the egg 

 material examined. Stiles and Bates did not clean the shells, and 

 their method of opening was to crack on the "edge of a sterile Petri 

 plate and shift the yolk from shell to shell in housewife fashion, to 

 effect a separation of the two substances. The plate used for crack- 

 ing the shell was also the container of the sample. Maurer does 

 not give the number of organisms occurring, merely stating their 

 presence or absence. 



The bacterial content of fresh eggs has been proved to be widely 

 diversified in the character of the organisms present, but their num- 

 bers are small. The varieties of organisms present will be considered 

 elsewhere. It may be said, however, that Pennington ^ did not find 

 B. coli in any of the 150 eggs examined; neither did Maurer in a 

 study of 160 eggs, many of which had dirty shells or were placed 

 under artificial conditions favoring shell penetration. B. coli were 

 found on the shells in many cases. Stiles and Bates found one egg 

 laid in the month of July that contained B. coli in the yolk. It is 

 possible, however, that this might have been the result of contamina- 

 tion while cracking on the edge of the Petri dish or separating white 

 and yolk by the shell method of the housewife. With the exception 

 of this one egg yolk wherein B. coli were reported, the examinations 

 of fresh eggs do not, from a practical industrial viewpoint, show 

 conflicting testimony. They agree fairly well in asserting that the 

 fresh, well-handled e.gg^ though not always sterile, is not, on the other 

 hand, infested by large numbers of bacteria, and B. coli are practically 

 never present. 



After bad handling or mistreatment the number of organisms 

 may, and frequently does, increase enormously. Whether they in- 

 variably appear in numbers after bad handling or age has inter- 

 fered with the integrity of some one or more of the component parts 

 of the Q,gg is a problem to be solved. The studies here chronicled 

 are expected to throw some light on this question. Such studies 

 would indicate also whether the large numbers of bacteria found in 

 certain eggs are due to a rapid increase of the original organisms 

 found in them even while still present in the oviduct, or whether an 

 additional infection through the shell is common in the course of 

 the usual routine of marketing. 



1 Bacteriological Studies on Eggs. Kansas State Agricultural College Bui. 180, 1911. 

 «J. Biol. Chem., 1910, 7 (2) : 109. 



