MICROCOCCUS MELITENSIS 



503 



in comparatively young cultures ; the usual form is, however, 

 that of a coccus.) It stains fairly readily with the ordinary 

 basic aniline stains, but loses the stain in Gram's method. It is 

 generally said to be a non -motile organism. Gordon, however, 

 is of a contrary opinion, and has recently demonstrated that it 

 possesses from one to four fiagella, which, however, are difficult 

 to stain. In the spleen of a patient dead of the disease it 

 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 of blood should be withdrawn from a vein and distributed in 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 micrococc us was found f -""' ~^~\^ 



by the members of the * 4 



Commission in the urine .^ . . 



of Malta fever patients in : r 



10 per cent, of the cases 

 examined ; it was some- 

 times scanty, but some- 

 times present in large 

 numbers. It has also 



, 



occasionally been obtained 

 from the faeces. 



Cultivation. This can 

 usually be effected by 

 making stroke cultures on 



agar tubes from the spleen PIG< 151 ._ MicrococcU8 melitensis, from 



two days' culture on agar at 37 C. 

 Stained with fuchsin. x 1000. 



pulp and incubating at 

 37 C. The colonies, 

 which are usually not 



visible before the third or fourth day, appear as small round 

 discs, slightly raised and of somewhat transparent appearance. 

 The maximum size 2 to 3 mm. in diameter 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 



