488 MICROORGANISMS IN AVATE1I 



BACILLUS THEEMOPHILUS 



Authority. Miquel, ' Monographic d'un Bacille vivant au-dela de 70 C.,' 

 dc 1 , Micrographie sjuk-ialement coH.sm-;v ! t'.s a la Jiactrrioloyic, mix Proto- 

 phytcs ct aux Protozoaires, Paris, No. 1, 1888, p. 3. 



Where Found. Occasionally in air. Found frequently in river-water, but 

 not in spring-water. Very prevalent in sewage-polluted water. Miquel found 

 as many as 1,000 in 1 c.c. of river Seine water collected at the bridge of Auster- 

 litz in Paris, and many more in the river-water below Paris. Its normal habitat 

 appears to be drain-water. It is also found in soil, as well as in the alimentary 

 canal of man and animals. If drops of drain-water be inoculated into broth- 

 tubes subsequently maintained at about 69 C., they become turbid in twenty- 

 four hours, and in nearly all cases contain the B. thermophUus, 



Microscopic Appearance. The dimensions of the bacillus vary according 

 to the temperature at which it is cultivated. Thus at 50 C. it is usually short, 

 and exhibits an oval spore at the end of the rod. At 60 C. it forms filaments, 

 and only a few spores are visible. At 70 C. the filaments acquire a granulated 

 appearance. At 71 to 72 C. no spores are found, and the bacillus is swollen 

 and resembles a necklace. It is not motile. 



Cultures. 



AGAR-AGAK TUBES. It will neither grow on gelatine at from 22 to 23 C., nor 

 on agar-agar between 30 and 40 C. At 42 to 45 C. a white raised meniscus- 

 shaped growth is visible on the agar. Microscopic examination reveals the 

 presence of a short plump bacillus, with a very highly refracting spore at one 

 end. 



BROTH. No growth at 40 C., even when preserved at this temperature for 

 thirty days, but at 42 C. and beyond the liquid becomes turbid in three to four 

 days, and at 50 C. in forty-eight hours, and still earlier at 60 C., when cloudy 

 isolated patches appear in the broth. It grows best at from 05 to 70. At 71 C. 

 the appearance of turbidity only commences after two days, whilst at 72 C. it 

 grows very badly. At the most favourable temperatures an abundant precipi- 

 tate forms at the bottom of the tube, and the liquid becomes clear. 



Remarks. It is not pathogenic to animals. When tin- temperature of the water 



is raised beyond 50 C\ it becomes an active putrefying .i^vnl . The fact that it is 

 found in the alimentary canal indicates, says Miquel. that it is capable of growing 

 slightly between 87 and 40 C. 



