Synthesis of enterotoxin B by Staphylococcus aureus strain S6 after recovery from heat injury

1973 ◽  
Vol 19 (12) ◽  
pp. 1463-1468 ◽  
Author(s):  
D. L. Collins-Thompson ◽  
A. Hurst ◽  
H. Kruse
Keyword(s):  
Heat Treatment ◽  
Staphylococcus Aureus ◽  
Salt Tolerance ◽  
Sodium Phosphate ◽  
Potassium Phosphate ◽  
Aureus Strain ◽  
Heat Injury ◽  
K Cells ◽  
Enterotoxin B ◽  
And Control

After sublethal heat treatment of Staphylococcus aureus S6 at 52C for 15 min in either 0.1 M sodium phosphate (Na cells) or 0.1 M potassium phosphate (K cells), more than 99% of the cells were unable to grow on a medium containing 7.5% NaCl. When placed in H and K medium the survivors recovered their salt tolerance and grew after a lag of 3 h (Na cells) or 5 h (K cells). In the absence of glucose, the total amount of enterotoxin B synthesized by the Na and K cells was similar to the control cells. Addition of 0.1% glucose to the medium increased the total amount of toxin formed by Na, K, and control cells.

Effect of glucose and pH on growth and enterotoxin B synthesis by Staphylococcus aureus, strain S6, after heat injury in sodium or potassium phosphate buffer

1973 ◽  
Vol 19 (7) ◽  
pp. 823-829 ◽  
Author(s):  
A. Hurst ◽  
D. L. Collins-Thompson ◽  
H. Kruse
Keyword(s):  
Phosphate Buffer ◽  
Potassium Phosphate ◽  
Aureus Strain ◽  
Lag Phase ◽  
Potassium Phosphate Buffer ◽  
Heat Injury ◽  
Glucose Levels ◽  
K Cells ◽  
Enterotoxin B ◽  
Straight Lines

Cells injured by heating at 52C for 15 min in sodium (Na cells) or potassium phosphate buffer (K cells) were allowed to grow and recover in media containing 0, 0.1%, and 1.0% glucose. Growth, acid, and enterotoxin B production was followed and compared with that of unheated control cells. Control cells growing in 0 and 0.1% glucose first lowered the pH, but injured cells did not. Straight lines were obtained from growth experiments when the ratio enterotoxin B/pH versus time was plotted. Statistical analysis of the slopes showed that Na cells differed from K cells. In 1.0% glucose, Na cells produced less acid than K cells. Na cells were 80%, control cells were 90%, and K cells were 99% repressed in their enterotoxin B synthesis. At all glucose levels, the lag phase of Na cells was about 2 h shorter than that of K cells. Heat injury caused a 30–40% loss of K+, but Na cells gained Na+ (34%) and K cells lost Na+ (28%). The K/Na ratio of Na cells was 2.75 and that of K cells was 15.75. It is argued that this difference could account for the differences observed between Na cells and K cells but cannot account for the total injury phenomenon.

Magnesium requirement of Staphylococcus aureus for repair from sublethal heat injury

1976 ◽  
Vol 22 (8) ◽  
pp. 1202-1205 ◽  
Author(s):  
Ashton Hughes ◽  
Andre Hurst
Keyword(s):  
Staphylococcus Aureus ◽  
Salt Tolerance ◽  
Ethylenediaminetetraacetic Acid ◽  
Potassium Phosphate ◽  
Optimal Conditions ◽  
Minimal Repair ◽  
Potassium Phosphate Buffer ◽  
Heat Injury ◽  
Synthetic Media ◽  
Mg Content

Heating in potassium phosphate buffer causes Staphylococcus aureus to lose its salt tolerance and 30–40% of its cellular Mg2+. Repair from injury (regain of salt tolerance) occurred when injured cells were incubated under optimal conditions in synthetic media containing penicillin to prevent growth. Cells died when phosphates or amino acids were omitted from the medium. Omission of vitamins, glucose, Na+, and K+ had no effect. Omission of Mg2+ diminished repair. In a minimal repair medium (MRM) which contained only 3 × 10−6 M Mg (as an impurity), injured cells rapidly regained their original Mg content. About 20–50% of the cells also regained their salt tolerance provided that less than 109 cells/ml were used. With 1010 cells/ml there was no repair and cellular Mg content was half that of the control. Addition of 10−3 M ethylenediaminetetraacetic acid (EDTA) to MRM also prevented repair. Addition of 10−2 M Mg to MRM + 10−3 M EDTA permitted complete repair.

Membrane mutations and production of enterotoxin B and alpha hemolysin in Staphylococcus aureus

1975 ◽  
Vol 21 (3) ◽  
pp. 275-280 ◽  
Author(s):  
Robert A. Altenbern
Keyword(s):  
Staphylococcus Aureus ◽  
Aureus Strain ◽  
Type B ◽  
Alpha Hemolysin ◽  
Osmotic Stability ◽  
Enterotoxin B

Staphylococcus aureus strain S-6, which produces enterotoxin type B (SEB), and strain 10-275, a high toxin-producing mutant derived from S-6, display pronounced differences in dye sensitivity, osmotic stability, and bacitracin sensitivity. Such characteristics are consistent with the concept that strain 10-275 is a membrane mutant of strain S-6. Some membrane mutants of S. aureus strain 14458 exhibit about two- to three-fold increases in SEB production whereas other membrane mutants show about twofold increases in α-hemolysin production. It is suggested that specific and independent membrane mutations control the secretory processes resulting in the extracellular elaboration of these exoproteins.

Enterotoxin B production by Staphylococcus aureus under controlled fatty acid nutrition induced by cerulenin

1977 ◽  
Vol 23 (9) ◽  
pp. 1145-1150 ◽  
Author(s):  
Robert A. Altenbern
Keyword(s):  
Fatty Acids ◽  
Staphylococcus Aureus ◽  
Fatty Acid ◽  
Membrane Fluidity ◽  
Unsaturated Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Basal Medium ◽  
Aureus Strain ◽  
Enterotoxin B ◽  
Fatty Acid Supplement

Cells of Staphylococcus aureus, strain S-6, can grow in the presence of 100 μg of cerulenin/ml if the basal medium is supplemented with certain saturated or unsaturated fatty acids. The production of enterotoxin B (SEB) is markedly influenced by both the ratio of saturated to unsaturated fatty acid and by the melting point of the unsaturated fatty acid supplement. The results presented suggest that a certain degree of membrane fluidity promotes maximum SEB production and that greater or lesser degrees of membrane fluidity prohibit substantial SEB formation but fail to affect final growth density.

Growth and enterotoxin B synthesis by Staphylococcus aureus S6 in associative growth with Pseudomonas aeruginosa

1973 ◽  
Vol 19 (10) ◽  
pp. 1197-1201 ◽  
Author(s):  
D. L. Collins-Thompson ◽  
B. Aris ◽  
A. Hurst
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Sodium Chloride ◽  
Salt Tolerance ◽  
Second Growth ◽  
Growth System ◽  
Pure Cultures ◽  
Enterotoxin B ◽  
Membrane Type ◽  
And Staphylococcus Aureus

The interaction of Pseudomonas aeruginosa and Staphylococcus aureus S6 was studied in two systems. In the first system, the two organisms were grown together in a single flask. Growth of P. aeruginosa was unaffected, but growth of S. aureus was modified. After 24 h, 99.9% of the staphylococci population lost their salt tolerance when plated on media containing 7.5% sodium chloride, and enterotoxin B synthesis by S. aureus was diminished. In the second growth system, pure cultures of P. aeruginosa and S. aureus were grown in membrane-type spinner flasks. The growth and salt tolerance of S. aureus was again affected, but to a lesser degree. Cultures of S. aureus from these experiments recovered their salt tolerance in 6 h when transferred to fresh medium.Nutrient deficiency, lack of oxygen, or pigment production by the pseudomonads did not contribute significantly to loss of salt tolerance or inhibition of enterotoxin B synthesis, but a staphylolytic enzyme(s) isolated from P. aeruginosa was shown to be responsible for the loss of these properties.

Repair of salt tolerance and recovery of lost D-alanine and magnesium following sublethal heating of Staphylococcus aureus are independent events

1981 ◽  
Vol 27 (6) ◽  
pp. 627-632 ◽  
Author(s):  
A. Hurst ◽  
A. Hughes
Keyword(s):  
Staphylococcus Aureus ◽  
Salt Tolerance ◽  
Phosphate Buffer ◽  
Synthetic Medium ◽  
Potassium Phosphate ◽  
Complex Media ◽  
Rich Medium ◽  
Potassium Phosphate Buffer ◽  
Heat Damage ◽  
Independent Events

Sublethal heating of Staphylococcus aureus S6 in potassium phosphate buffer caused loss of salt tolerance, D-alanine, and magnesium. During incubation in rich complex media all three of the damaged sites were repaired. Repair occurred more slowly but went to completion in a dilute synthetic medium (DSM), free of D-ala. DSM plus penicillin or D-cycloserine allowed repair of salt tolerance but recovery of normal levels of D-ala or Mg was prevented. When DSM-repaired cells were cultured into fresh rich medium they grew rapidly after a short lag. Cells which had acquired their salt tolerance in DSM plus cycloserine and were D-ala and Mg deficient grew slowly and had a lag of 3 h. We suggest that heat damage has two separate primary targets in S. aureus cells: the membrane, which is manifested by loss of salt tolerance, and a second site, possibly teichoic acids, manifested by loss of D-ala and Mg.

Effect of Magnesium and Iron on the Growth of and Production of Extracellular Proteins by Staphylococcus aureus Strain S-6

1988 ◽  
Vol 51 (9) ◽  
pp. 731-733 ◽  
Author(s):  
ELISA YOKO HIROOKA ◽  
SONIA PRESA C. de SALZBERG ◽  
MERLIN S. BERGDOLL
Keyword(s):  
Staphylococcus Aureus ◽  
Dry Weight ◽  
Extracellular Proteins ◽  
Cellular Morphology ◽  
Dnase Activity ◽  
Aureus Strain ◽  
Gram Negative ◽  
Enterotoxin B ◽  
Mineral Ions

The effect of magnesium and iron on the growth, cellular morphology, deoxyribonuclease, coagulase, and enterotoxin B (SEB) production of Staphylococcus aureus strain S-6 in a pancreatic digest of casein (NAK) which had been treated with alumina to remove mineral ions was determined. Growth of S. aureus in the treated NAK medium (NAKSA) was minimal; the morphology of the cells was heterogenous with many large cells as well as some that were gram negative. The cells gradually reverted towards normal as the Mg2+ concentration was increased to 1.1 μg/ml. Cell dry weight increased from 0.36 ± 0.27 mg/ml to 1.16 ± 0.41 mg/ml, DNase activity increased from 7.6 units/mg dry weight to 77.0 units/mg dry weight, and SEB production increased from 12.2 to 54.3 μg/mg cell dry weight when the Mg2+ content was increased to 1.1 μg/ml. Increasing the Fe2+ content above the 0.4 μg/ml in the NAKSA medium containing 1.1 μg/Mg2+ resulted in decreases in dry weight and DNase activity, a slight increase in SEB production, and a relatively large increase in coagulase production.

A technique for obtaining linear heat-survivor curves with Staphylococcus aureus and its application to the assay of sublethal heat injury

1975 ◽  
Vol 21 (11) ◽  
pp. 1880-1884
Author(s):  
Andre Hurst ◽  
Ashton Hughes ◽  
Georgia Whitfield
Keyword(s):  
Heat Treatment ◽  
Staphylococcus Aureus ◽  
Modified Technique ◽  
Heat Injury ◽  
Linear Heat ◽  
Heat Treated ◽  
Batch Technique ◽  
D Values

Staphylococcus aureus was grown in a complex (HK) medium either by a batch technique or by a modified batch technique after growth in a chemostat. These cultures were heat-treated at 52 °C, and counted on trypticase soy agar (TSA) or trypticase soy agar containing 7.5% NaCl (TSAS). When linear heat-survivor curves were obtained decimal reduction times (D52°C) could be calculated from the TSA counts and pseudodecimal reduction times (D′52°C) from the TSAS counts. The D or D′ values of batch-grown cells varied from 22 to 133 min and from 3 to 12 min, respectively. With cells grown by the modified technique the values were less variable (D was 22–51 min and D′ was 3–7 min). D and D′ values could be calculated from the same heat treatment in two of six estimations with batch-grown cells but in six of six estimations with cells grown by the modified technique.

The reliability of selective media for the enumeration of unheated and heated staphylococci

1974 ◽  
Vol 20 (12) ◽  
pp. 1735-1744 ◽  
Author(s):  
M. E. Stiles ◽  
P. C. Clark
Keyword(s):  
Heat Treatment ◽  
Staphylococcus Aureus ◽  
Relative Efficiency ◽  
Protective Action ◽  
Egg Yolk ◽  
Protective Agent ◽  
Selective Media ◽  
Heat Injury

The relative efficiency of 15 selective media for enumerating unheated and sublethally heated strains of Staphylococcus aureus was tested against tryptic soy agar (Difco). Baird-Parker's egg yolk tellurite glycine pyruvate agar was found to be the medium of choice for both unheated and sublethally heated cells. Tellurite polymyxin egg yolk agar and egg yolk azide agar also gave favorable results. For unheated cells, Vogel-Johnson agar and tellurite glycine agar gave satisfactory results, but after heat treatment, even after a 10-h enrichment in tryptic soy broth for resuscitation of the heat injury, these media gave unreliable counts. Egg yolk acted not only as a diagnostic, but also as a protective agent in selective media for staphylococci. The protective action of egg yolk was more effective in azide- and tellurite-containing selective media than in salt-containing selective media.

Enumeration of sublethally heated staphylococci in some dried foods

1976 ◽  
Vol 22 (5) ◽  
pp. 677-683 ◽  
Author(s):  
Andre Hurst ◽  
G. S. Hendry ◽  
Ashton Hughes ◽  
Beverly Paley
Keyword(s):  
Staphylococcus Aureus ◽  
Salt Tolerance ◽  
Adenosine Triphosphate ◽  
Yeast Extract ◽  
Skim Milk ◽  
Most Probable Number ◽  
Acetyl Phosphate ◽  
Sodium Pyruvate ◽  
Probable Number ◽  
Heat Injury

The effect of 45 substances to restore the salt tolerance of sublethally heat-injured Staphylococcus aureus was tested. Sodium pyruvate, yeast extract, L-histidine, casitone (Difco), adenosine triphosphate, and acetyl phosphate were effective. For enumeration a repair medium was first used, containing sodium pyruvate and penicillin in 1% skim milk. This step was followed by counting on Baird-Parker agar with penicillinase. This method was selective; fewer than 100 staphylococci/g food could be enumerated and it gave counts about 8 times higher than the method of Giolitti and Cantoni used as a five-tube most probable number technique. Heat injury sensitized S. aureus to polymyxin.

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