490 



MALTA FEVER 



occurs irregularly scattered through the congested pulp ; it may 

 also be found in small numbers post mortem in the capillaries of 

 various organs. It may be cultivated from the blood during life 

 in a considerable proportion of cases ; for this purpose 5 to 10 c.c. 

 of blood should be withdrawn from a vein and distributed in 

 small flasks of bouillon. The micrococcus was found by the 

 members of the Commission in the urine of Malta fever patients 

 in. 10 per cent, of the cases examined ; it was sometimes scanty, 

 but sometimes present in large numbers. It has also occasionally 

 been obtained from the faeces. 



Cultivation. This can usually readily be effected by making 

 stroke cultures on agar tubes from the spleen pulp and incub- 

 ating at 37 C. The 

 colonies, which are usually 

 not visible before the 

 third or fourth day, ap- 

 pear as small round discs, 

 ;' l % " j. slightly raised and of some- 

 what transparent appear- 

 | ance. The maximum size 

 2 to 3 mm. in diameter 

 '"I is reached about the 

 ninth day; at this period 

 by reflected light they 

 appear pearly white, while 

 by transmitted light they 

 have a yellowish tint in the 

 centre, bluish white at the 

 periphery. A stroke culture 

 shows a layer of growth 

 of similar appearance with 



somewhat serrated margins. Old cultures assume a buff tint. 

 The optimum temperature is 37 C., but growth still occurs down 

 to about 20 C. On gelatin at summer temperature growth is 

 extremely slow after two or three weeks, in a puncture culture, 

 there is a delicate line of growth along the needle track and a 

 small flat expansion of growth on the surface. There is no 

 liquefaction of the medium. In bouillon there occurs a general 

 turbidity with flocculent deposit at the bottom ; on the surface 

 there is no formation of a pellicle. The reaction of the media 

 ought to be very faintly alkaline, as marked alkalinity interferes 

 with the growth; a reaction of + 10 (p. 34) has been found 

 very suitable. On potatoes no visible growth takes place even 

 at the body temperature, though the organism multiplies to a 



FIG. 147. Micrococcus meliteusis, from a 



two days' culture on agar at 37 C. 



Stained with fuchsin. x 1000. 



