412 DESCRIPTION OF SOME SPECIES OF MILK BACTERIA 



Comparative Features — Continued. 



B. typhosus, B. coli. 



Milk — Not curdled by the bacillus (at 37° C). Milk is curdled, within 24 to 48 hours 

 No acid production. at 37° C. Abundant acid production. 



Indol — In bouillon and Witte's peptone water, Indol is present. 



no production of indol. 

 Bouillon containing 0*3 per cent. Phenol or Grows well and uniformly throughout 



Formalin (i : 7000) — No growth. 

 Lactose-bouillon at 37° C. — No gas production. 

 Neutral-red glucose-agar — No change. 

 Glucose or lactose media, shake cultures — No 



gas production. 

 Potato — An "invisible growth" if the potato Thick, yellowish-white growth, later be- 



is acid in reaction. coming brown in colour. 



25 per cent, gelatine at 37° C. — Strongly and Gelatine remains clear within 48 hours, 



but a thick pellicle forms on the 

 surface. 

 Rapid growth ; large brown colonies. 



medium. 

 Gas production occurs. 

 Marked green fluorescence. 

 Marked gas production. 



uniformly turbid (Klein). No pellicle. 



Eisner'' s iodised potato- gelatine — Slow growth ; 



small transparent colonies. 

 Proskauer and Capaldi's Medium, No. I — No 



growth ; no change in reaction. 

 WidaPs reaction — Bacilli became motionless 



and agglutinate! when suspended in blood 



serum from a typhoid patient. (_See 



Appendix.) 



Thermal death-point — 62° C. for five minutes 66° C. for five minutes (Klein). 



(Klein). 

 Vitality in water or sewage — B. typhosus soon 



ceases to multiply and more or less readily 



dies. 



Growth ; acid reaction. 



B. coli remains motile and not aggluti- 

 nated. 



B. coli retains vitality and power of 

 self-multiplication. 



P/eiffer's inoculation test with anti-typhoid serum 

 — Negative result. 



Positive result, variable symptoms 

 according to virulence of bacillus. 



BACILLUS COMMUNIS LACTIS, 

 Nos. 1 and 2 (Conn). 



Source and habitat — Milk. 



Morphology — 6 to i ^ long. May 

 occur as chains (bouillon). 



Staining reaction —Ordinary aniline 

 stains. 



Biology: cultural characters {includ- 

 ing biochemical features). 



Gelatine plates and tubes — 

 Smooth, round, white colonies (like 

 B. coli) raised centre ; moist and 

 glistening. Needle growth abun- 

 dant in stab-cultures with white, 

 flat, glistening growth on surface. 



Agar plates and tubes — No. i 

 not characteristic ; No. 2 moder- 

 ately thick, moist smooth trans- 

 parent growth. 



Potato — No. I a slight growth 

 having a lemon tinge ; No. 2 white 

 moist thick growth. 



Milk — Nos. I and 2 no growth. 



Aerobic. 



Non-pathogenic. 



BACILLUS DIPHTHERIA 



(Klebs-Loffler). 



Source and habitat — Throat, nose, 

 larynx, trachea, more rarely 



