92 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Gaertner organisms when dulcite broth containing ' 05 p.c. of rnala- 

 chite-green was employed. In view of the possibility that not all the 

 members of this group will flourish in • 05 p.c. malachite-green broth, 

 the author advises that direct plating methods should also be used. 



Animal inoculation methods are not trustworthy, since it is not 

 uncommon to obtain Gaertner organisms from the heart-blood of animals 

 that have been inoculated with organisms other than those of the Gaertner 

 group ; the pathogenic effects of the B. coli group may entirely mask 

 those produced by the Gaertner group ; and it is also possible that 

 Gaertner group organisms may be present but non-virulent. 



The author examined the intestinal contents of some healthy animals : 

 three bullocks, six pigs, and one calf ; he found in the bullocks no 

 organisms resembling those of the Gaertner group ; from five pigs 

 organisms culturally resembling B. paratyphoid A were isolated ; only 

 four bacilli were isolated from the pigs which culturally were allied to the 

 other Gaertner sub-groups, and of these one did not ferment dulcite, while 

 the other three fermented saccharose ; none of these organisms were 

 agglutinated by sera obtained from rabbits immunised from well-known 

 members of the Gaertner group. The calf showed both in the colon 

 and caecum numerous organisms culturally indistinguishable from the 

 ordinary Gaertner group bacteria, but when tested against different 

 immune sera these organisms were not agglutinated ; they were, how- 

 ever, highly pathogenic, and the author considers that further research 

 is needed to determine to what extent these organisms are common in 

 calves, and whether their presence is hurtful to those using such animals. 



Bacterial Studies of Milk.* — W. G. Savage finds that streptococci 

 were present in the majority of samples of milk taken from healthy 

 cows ; no cocci resembling the Diplococcus intracellular is meningitidis 

 Avere met with ; staphylococci were found in large numbers in most of 

 the plates made from cetitrifuged milk deposits, and were recognised as 

 two distinct classes ; bacilli were only occasionally met with, and in 

 scanty numbers. 



The author groups the streptococci morphologically, according to 

 length of chain, into short, medium, and long, and biologically according 

 to thek reaction with different sugars and alcohol media, and also 

 according to their pathogenicity, as shown by their action on mice, 

 although in this respect, out of twenty-five streptococci, the virulence of 

 which was tested, the results were in every case negative. 



The author finds that the mere presence of streptococci bears no 

 relation to the existence of local condition of the cow, the number of 

 calves, or the stage of pregnancy ; but there seems to be a connection 

 between local condition and the presence of a certain kind of strepto- 

 coccus. This variety forms long chains ; stains by Gram's method ; 

 grows at 21° C. and at 37° C. ; clots milk within 3 days ; ferments 

 lactose, saccharose, and raffinose (and usually salicin), whereas mannite, 

 coniferin, and inulin are unaffected. This organism was isolated from 

 the milk of seven cows, three of which had ulcerated teats, and a fourth 

 had nodules at base of two teats. 



Referring to the staphylococci present in milk, the author considers 



* Rep. Local Govt. Board, 1906-7, p. 205. 



