The Thermal Death Point and Limiting Hydrogen Ion Concentration of Pathogenic Streptococci

Ayers, S. Henry; Johnson, W. T.; Davis, Brett

doi:10.1086/infdis/23.3.290

Cited by 29 publications

(15 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…for thirty minutes. The same workers, along with Davis (1918), isolated 27 strains of pathogenic streptococci and determined their thermal death point in milk; this was never higher than 60°C. in the case of an exposure of 30 minutes.…”

Section: Experiments On the Pasteurisation Of Milk With Reference Tomentioning

confidence: 99%

Experiments on the Pasteurisation of Milk, with reference to the Efficiency of Commercial Pasteurisation

Jenkins

1926

J. Hyg.

View full text Add to dashboard Cite

Pasteurisation at 62.8° C. (145° F.) for 30 minutes leads to a marked reduction inthe total bacterial contentof milk, varying for different specimens from 94 to 99·8 per cent., when the process is carried out under the most exact conditions. At lower temperatures,e.g.60° C., the percentage reduction may vary widely—from 51·6 to 97·4 per cent. The percentage reduction has been found to be slightly less when the same specimens of milk are pasteurised in a large scale apparatus than when treated in small quantities under laboratory conditions, the average reduction being 91·2 per cent, in the former case and 98·4 per cent, in the latter. The reasons for this are discussed.An effectively pasteurised milk should not contain lactose-fermenting bacilli in 1 c.c, and theB. colicontent is a valuable index of the efficiency of a pasteurising process.Milk containingB. tuberculosis, when pasteurised at 62·8° C. for 30 minutes (1) in tubes in a water bath in the laboratory, and (2) on a large scale by a commercial plant, is rendered non-infective to guinea-pigs. By laboratory pasteurisation, even at 60° C. for 30 minutes, milk containing tubercle bacilli is rendered non-infective.

show abstract

Section: Experiments On the Pasteurisation Of Milk With Reference Tomentioning

confidence: 99%

Experiments on the Pasteurisation of Milk, with reference to the Efficiency of Commercial Pasteurisation

Jenkins

1926

J. Hyg.

View full text Add to dashboard Cite

show abstract

“…Method 8. Thermal Resistance.--The method employed was similar to that recommended by Ayers, Johnson, and Davis (25). Cultures grown for 18 hours in sterile milk were heated for exactly 30 minutes in a water bath at 56°C.…”

Section: Methods 1 Reaction In Litmusmentioning

confidence: 99%

Studies on a Non-Hemolytic Streptococcus Isolated From the Respiratory Tract of Human Beings

Mirick¹,

Thomas²,

Curnen³

et al. 1944

Journal of Experimental Medicine

View full text Add to dashboard Cite

In the course of an investigation of the etiology of primary atypical pneumonia attempts were made to isolate infectious agents from specimens obtained from patients with this clinical syndrome. Not only were efforts made to recover virus-like agents from such specimens but also the various bacterial species encountered were studied. From lung tissues obtained from two fatal cases of primary atypical pneumonia a non-hemolytic streptococcus was isolate& In a preliminary communication (1) the results of certain studies carried out with this microorganism were reported. It was shown that some patients with primary atypical pneumonia developed in their serum during convalescence antibodies which agglutinated this streptococcus and also yielded precipitates with appropriate extracts derived from the bacterial cells. In most instances similar antibodies were found not to develop during convalescence from other acute infectious diseases.Since this non-hemolytic streptococcus appeared to possess certain interesting properties it has been studied in detail. Efforts have been directed toward determining its relationship to other streptococci. Moreover, attempts have

show abstract

“…Cultures of hemolytic streptococci are known to develop an acidity of p H 5 to p H 5.2 in both sugar free and sugar containing media (8,9,10). In view of this fact one would expect the organisms to render cells that they had killed more acid if anything.…”

Section: The Changes In Cells Killed With Other Organismsmentioning

confidence: 99%

The Relative Reaction Within Living Mammalian Tissues

Gilding

1930

Journal of Experimental Medicine

View full text Add to dashboard Cite

By a variety of methods necrosis of individual cells was produced in the living animal. Cell death was found to be clearly perceptible by means of the changes in the color of segregated erythrolitmin at a time when it was not as yet recognizable by ordinary histological methods. The hue of the dye pointed to an alteration in the direction of alkalinity; but the extent of this could not be determined owing to the limited range of the indicator Cartilage damaged by freezing in situ becomes alkaline, its reaction now approximating that of the blood. The findings support the view that within the body the autolysis of individual cells and of small tissue masses may take place under the circumstances of a slight alkalinity.

show abstract

The Thermal Death Point and Limiting Hydrogen Ion Concentration of Pathogenic Streptococci

Cited by 29 publications

References 0 publications

Experiments on the Pasteurisation of Milk, with reference to the Efficiency of Commercial Pasteurisation

Experiments on the Pasteurisation of Milk, with reference to the Efficiency of Commercial Pasteurisation

Studies on a Non-Hemolytic Streptococcus Isolated From the Respiratory Tract of Human Beings

The Relative Reaction Within Living Mammalian Tissues

Contact Info

Product

Resources

About