202 DEPARTMENT OF THE NAVAL SERVICE 



8 GEORGE V, A. 1918 



Aesculin agar. — ^One loop from peptone broth culture streaked on plates; in 24 



hours 37° C. brown to black reaction. 

 Aesculin broth. — The typical black reaction not given after 7 days; change only 



to brown. 

 MacConlcey's N.R.B. hroth. — In 48 hours 37° C. an eosin tint but no reduction to 



canary yellow after 7 days. 

 Gelatine colonies. — Eoom temperature (1st appearance) in 72 hours surface colo- 

 nies small, average ^ mm. diameter, glistening flat, round; by transmitted 

 light bluish white, almost transparent ; characteristic ring in gelatine as noted. 

 Culture 32; surface colonies yellowish white, small, round. Under the low 

 power objective surface colonies round distinctly granular and dark yellow 

 centre, surrounded by pale border and edges entire and hyaline; on gelatine, 

 the colonies unlike those previously described. 



N.B. — On referring to the notes made when this culture was originally isolated 

 six months ago, I find that on agar the colonies were characteristically 

 different from the colonies of Ciiltures 32, 34 or 35. It is of interest to 

 note that this individuality has been maintained throughout a period of 

 this length, and in spite of having many times been subcultured on labora- 

 tory media. 

 Agar Colonies. — 20 hours, 37 °C. growth rapid; surface colonies 1-14 mm. dia- 

 meter; flat, glistening, iridescent; some colonies extending as thin blue pro- 

 tuberances over the medium ; by transmitted light colonies bluish, little darker 

 and more opaque in centre. Subsurface colonies up to -25 mm. diameter. 

 Under the low power objective surface colonies coarsely granular, immediate 

 centre slightly darker and well defined; remainder same structure throughout; 

 edges entire ; subsurface colonies compact, grumose to "mound-like" structure ; 

 often the surrounding medium a light ferric colour due to precipitated gra- 

 nules with no definite outline. 



Temperature Relations: — 



Thermal Death Point. — 10 minutes exposure to 60° C. in nutrient broth. 

 Optimum Temperature. — Growth satisfactory when incubated either at room 



temperature or at 37°C. Most satisfactory growth at 37°C. 

 Vitality on Culture Media. — The culture survives several months on artificial 



media, agar or gelatine. 



Relation to Oxygen: — Facultative anaerobe; incubated for 36 hours at 37° C. under 

 anaerobic conditions grows on glucose agar as pale bluish thin film along track 

 of needle, transmitted light; spreading over slope as discrete colonies; heavy cloudy 

 growth in condensation water; much froth in tube, gas bubbles I cm. diameter 

 throughout medium. The organism grows equally well aerobically or anaerobic- 

 ally. 



Biochemical Reactions: 



Indol production Indol not produced. 



Reduction of nitrates Nitrates reduced to nitrites. 



Voges-Proskauer reaction Positive. 



Methyl red reaction Alkaline. 



Fermentation of Carhohydrates: The culture ferments lactose to acid, but gas is 

 not produced until 72 hours after inoculation; the amount then is small and 

 no increase is observed on further incubation; glucose, saccharose, xylose, 

 arabinose, and mannite are fermented to acid with profuse evolution of gas 

 within 24 hours. The action upon raffinose is feeble. The Andrade indicator 



