Differential Methods For Detecting The Typhoid Bacillus In Infected Water And Milk

Abstract

It is of the greatest importance in tests of the sanitary quality of water and milk supplies that organisms which specifically cause infectious diseases through such sources shall be subject to methods of rapid and definite isolation. Up to the present time this has been a matter of great difficulty and uncertainty owing to the fact that the disease germs which occur in water and especially in milk are intermingled with, and greatly outnumbered by, other intestinal germs and many species of common so-called air and water bacteria. CHEMICAL PRECIPITATION AND AGGLUTINATION. Many methods have been employed in isolating or attempting to isolate the typhoid bacillus from water. Processes involving chemical precipitation have been studied by Vallet,' Schuder," Ficker,' Mtiller,s Willson," Nietor,? and Ditthorn and Gildemeister,? the latter using ox bile as an enrichment medium after chemical precipitation. Agglutination has also been used in enrichment methods for the isolation of B. typhosus by Adami and Chopin," Klotz." Shipilewski,xo and Altschuler. II INDICATOR DYES AND DIFFERENTIAL CHEMICALS.

Studies on the Classification of the Colon-Typhoid Group of Bacteria With Special Reference to Their Fermentative Reactions

“…Nowack (1905) thought that a slightly alkaline reaction exerted a selective influence on the typhoid organism. Jackson and Melia (1909) found B. typhosus more resistant to the action of bile salts than B. coli. Davis (1914) has studied the resistance of the members of the colon-typhoid group to potassium tellurite, and finds that the colon-aerogenes forms are most resistant, followed in succession by the paratyphoid B and Gaertner group, B. typhosus, B. paratyphosus A and the dysenteries.…”

“…This group of organisms, of which B. coli is the most familiar example, is distinguished from all the organisms of the dysentery-typhoid-paratyphoid series by the power of fermenting lactose and from the B. aerogenes types by the fact that in its fermentation it produces equal volumes of CO2 and H2 (low ratio fermentation of Clark and Lubs). Its members differ from the STUDIES ON THE COLON-TYPHOID GROUP OF BACTERIA 483 the green dyes (Loeffler, 1903, Lentz and Tietz, 1903, Krumwiede and Pratt, 1914, caffeine (Hoffman and Ficher, 1904), and bile salts (Jackson and Melia, 1909). The further subdivision of the colon group of bacteria was first attempted on the basis of the fermentation of sucrose.…”

Elements of water bacteriology with special reference to sanitary water analysis by Samuel Cate Prescott and Charles-Edward Amory Winslow

“…The Hesse medium has been used with great success by Jackson and Melia (1909). Its general composition is as follows: tinguished from those of B. coli by the fact that they grow to a considerable size, often several centimeters in diameter and show a broad translucent or scarcely turbid zone between the white opaque centre or nucleus and the perfectly circular narrow white seam or edge.…”

Elements of water bacteriology, with special reference to sanitary water analysis

“…The Hesse medium has been used with great success by Jackson and Melia (1909). Its general composition is as follows: The important fact that cafifein has an inhibitory action on colon bacilli, announced by Roth (Roth, 1903) has given rise to much investigation, and ofifers one of the most promising methods for the isolation of the typhoid bacillus from water.…”

“…In this country marked success in the isolation of the typhoid bacillus has been attained by the use of lactose bile as an enrichment medium. Jackson (Jackson and Melia, 1909), the principal exponent of this procedure, recommends that sterilized undiluted fresh ox gall (or an II per cent solution of dry fresh ox gall) containing i per cent of peptone and i per cent of lactose be made up in 40 c.c. amounts in fermentation tubes to which varying amounts of water, up to 10 c.c.…”