724 Agricultaml Gazette of S.S.W. {Oct. 2, 1920. 



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Reinfection of Pasteurised Cream from Dusty Koads. 



Recently it was necessary to visit a factory situated on the side of a road 

 that is noted for its dustiness and along which ronsideiahle traffic passes. 

 The yard of the factory on to which opens the cream platform, the pasteuriser 

 and the cream pipe-coolers, was also subject to invasions of dust, although 

 the company had been advis(!d to asphalt or concrete it. At the time 

 of the visit these conditions were considerably modified through rain having 

 fallen during the night, and also through it being a calm day. However, as 

 the cream was being passed over the exposed pipe-coolers fronj the pasteuriser, 

 a plate was exposed for tive minutes within ;i few feet of the cooler, in order 

 to ascertain if, under the good conditions prevailing that day, any reinfection 

 of the pasteurised cream was taking place by dust-borne germs. The 

 accomi)anying photograph shows tlie result of this exposure, and demonstrates 



Plate Culture from Air Exposure. 

 Indicatinjf contamination of cream by dust, even after rain. 



the enormous amount of contamination that was taking place even under 

 such favourable conditions. It can be imagined how great the reinfection 

 must be on a windy, dusty day. The oiganisms shown largely belong to the 

 coliform group, and evidently they come from the manure of horses and 

 other animals, which, after being pulverised into dust in a dry state, has 

 impregnated tln> surrouniling atmosphere. 



A factory so situated should have its yard concreted or aspiialtcd, and steps 

 should be taken in conjunction with the local authorities to have the road in 

 front of the factory either oiled or asphalted, in order to keep down the dust. 

 Dairy factory companies incur much exjiense in jiasteurising cream and then 

 neglect simple means of maintaining the improved conditions. It is intended 

 in future to take more active steps to have tlie dust nuisance abated in such 

 eases. — L. 'I\ MacInnrs, Dairy Expert. 



