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.

ICMSF methods studies. X. An international comparative study of four media for the enumeration of Staphylococcus aureus in foods

1978 ◽  
Vol 24 (3) ◽  
pp. 274-281 ◽  
Author(s):  
M. K. Rayman ◽  
J. J. Devoyod ◽  
U. Purvis ◽  
D. Kusch ◽  
J. Lanier ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Comparative Study ◽  
Egg Yolk ◽  
Nuclease Activity ◽  
Selective Media ◽  
International Comparative Study ◽  
Significant Difference ◽  
The Media ◽  
International Comparative

An international comparative study, undertaken by six laboratories to assess the performance of four selective media commonly used for the enumeration of Staphylococcus aureus in foods, revealed that Baird-Parker agar performed most satisfactorily. There was no significant difference among milk salt, tellurite polymyxin egg yolk, and kalium rhodanid – actidione – natriumazid – eigelb – pyruvat (KRANEP) agars. The type of food examined appeared to influence the performance of the media, but no specific patterns could be determined. Cultures yielding 3+ and 4+ coagulase reactions are most likely to possess thermostable nuclease activity, and are therefore most likely to be S. aureus.

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.

Comparison of selective media for the enumeration of sublethally heated food-poisoning strains of Staphylococcus aureus

1974 ◽  
Vol 20 (7) ◽  
pp. 1072-1075 ◽  
Author(s):  
D. L. Collins-Thompson ◽  
A. Hurst ◽  
B. Aris
Keyword(s):  
Staphylococcus Aureus ◽  
Phosphate Buffer ◽  
Food Poisoning ◽  
Potassium Phosphate ◽  
Egg Yolk ◽  
Potassium Phosphate Buffer ◽  
Mannitol Salt Agar ◽  
Selective Media

Staphylococcus aureus strains (19 food-poisoning strains) were heated at 52C for 15 min in 100 mM potassium phosphate buffer. The sublethally heated organisms were enumerated on seven selective media commonly used for quantitating S. aureus. Compared to trypticase soy agar, Baird-Parker agar was the only medium which was satisfactory with all cultures tested. The remaining selective media gave unsatisfactory recoveries with one or more of the strains tested and are listed in the following order of decreasing acceptability: tellurite glycine agar, egg yolk azide agar, phenolphthalein phosphate agar with polymyxin, mannitol salt agar, Vogel Johnson agar.

scholarly journals COMPARATIVE EVALUATION OF SIX SELECTIVE MEDIA FOR THE DETECTION AND ENUMERATION OF STAPHYLOCOCCUS AUREUS IN FOODS

1974 ◽  
Vol 25 (4) ◽  
pp. 10
Author(s):  
Β. ΑΛΜΠΑΛΑΣ
Keyword(s):  
Staphylococcus Aureus ◽  
Comparative Evaluation ◽  
Egg Yolk ◽  
Mannitol Salt Agar ◽  
Selective Media ◽  
Pure Cultures ◽  
The Media ◽  
Coagulase Positive Staphylococci ◽  
The Ideal

Six selective media for the detection and enumeration of coagulase-positive staphylococci werl ctudied evaluated for their efficiency in the recovery and easy recognition of five strains of Staphylococcus aureus. They were Mannitol Salt agar (MS', Tellurite Polymyxine Egg Yolk agar (TPEY),Egg Yolk Azide Agar (EYAA), Egg yolk Tellurite Glycine Pyruvate Agar (ETGPA). Milk Salt Agar (MSA), in combination with Salt Egg Yolk Agar (SEYA), and Vogel-Johnson agar (VJ), after enrichement in Trypticase Soy Broth 10V» NaCl.The recovery of the used strains was evaluated in pure cultures and after inoculation in various foods. None of the tested media was proved to be the ideal one. The media TPEY, ETGRA. and EYAA were considered as the nost appropriate for the detection of S. aureus in foods. The selective ability of eash medium is greatly depended on the strain and the food involved The simultaneoue use of two selective media is suggested if that is possible.

Reliability of Selective Media for Recovery of Staphylococci from Cheese

1977 ◽  
Vol 40 (1) ◽  
pp. 11-16 ◽  
Author(s):  
M. E. STILES
Keyword(s):  
Staphylococcus Aureus ◽  
Significant Interaction ◽  
Egg Yolk ◽  
Selective Medium ◽  
Selective Agent ◽  
Mannitol Salt Agar ◽  
Selective Media ◽  
Cheese Ripening ◽  
Different Strains ◽  
Blood Agar Base

The reliability of 12 selective media for recovery of four different strains of Staphylococcus aureus inoculated at manufacture into three cheese types was determined. Selective medium and time of ripening had a highly significant effect (p < 0.001) on reliability of the staphylococcal count. In addition, highly significant interaction effects were observed. The most reliable medium in the overall analysis was mannitol salt agar. However, this medium was not equally reliable at all times during ripening, and use of both mannitol salt agar and Staphylococcus medium no. 110 is recommended. The tellurite- and azide-based selective media were generally unsatisfactory, however tellurite glycine agar, Vogel Johnson (VJ) agar, and azide blood agar base were totally unreliable. In general, the salt-based selective media were most reliable. This applied also to the egg yolk media that use salt as the selective agent. Salt egg yolk agar and Colbeck's egg yolk medium generally gave higher recoveries of S. aureus than did Baird-Parker medium, Crisley et al. tellurite polymyxin egg yolk agar, and Hopton egg yolk azide agar, except in the unripened cheeses. The debilitating effect of cheese ripening on the staphylococcal cells was not eliminated by the egg yolk tellurite and azide media.

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.

scholarly journals Protective effect of chlorpromazine on endotoxin toxicity and TNF production in glucocorticoid-sensitive and glucocorticoid-resistant models of endotoxic shock.

1991 ◽  
Vol 173 (6) ◽  
pp. 1305-1310 ◽  
Author(s):  
M Gadina ◽  
R Bertini ◽  
M Mengozzi ◽  
M Zandalasini ◽  
A Mantovani ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Actinomycin D ◽  
Protective Action ◽  
Endotoxic Shock ◽  
Serum Levels ◽  
Inhibitory Effect ◽  
Protective Agent ◽  
Initial Correlations ◽  
Necrosis Factor

The present study was designed to define the potential of chlorpromazine (CPZ) as a protective agent against lipopolysaccharide (LPS) toxicity in comparison with glucocorticoids, and to obtain initial correlations with its effects on the levels of tumor necrosis factor (TNF), a pivotal mediator of endotoxic shock. It was found that CPZ protects mice, normal or adrenalectomized, and guinea pigs against lethality of LPS, and inhibited TNF serum levels, like dexamethasone (DEX), a well-known inhibitor of TNF synthesis. CPZ protected against LPS lethality when administered 30 minutes (min) before, simultaneously, or up to 10 min after LPS and was ineffective when given 30 min after LPS, paralleling the inhibitory effect on TNF production. In another experimental model, where mice were sensitized to LPS toxicity by actinomycin D, CPZ significantly inhibited LPS lethality and hepatotoxicity, whereas under these conditions DEX was inactive. These experiments indicate that CPZ has a protective action in both glucocorticoid-sensitive and -resistant models of endotoxic shock.

scholarly journals Characterization of non-typable strains ofStaphylococcus aureusfrom cases of hospital infection

1987 ◽  
Vol 99 (1) ◽  
pp. 191-200 ◽  
Author(s):  
Ana Vindel ◽  
Cecilia Martín-Bourgon ◽  
Juan A. Saez-Nieto ◽  
Saez Nieto
Keyword(s):  
Heat Treatment ◽  
Staphylococcus Aureus ◽  
Thermal Shock ◽  
Hospital Infection ◽  
Phage Typing ◽  
Alternative Methods ◽  
Sporadic Cases

SUMMARYA high percentage of non-typable (NT)Staphylococcus aureusstrains was isolated in Spanish hospitals during 1984 and 1985. Several alternative methods of typing were employed to study these isolates. These were: phage-typing at 1000 × RTD, phage-typing after heat-treatment (48 °C), thermal shock (56 °C), reverse-typing and induction of additional phages. Using these methods the number of NT isolates was reducedby 60%. Best results were obtained with heat-treatment. Additional phages and reverse-typing were also useful.A scheme for the study of outbreaks and sporadic cases caused by NT strains is proposed using the methods described.

scholarly journals Studies on the growth and survival ofStaphylococcus aureusin corned beef

1983 ◽  
Vol 91 (3) ◽  
pp. 467-478 ◽  
Author(s):  
J. M. Mansfield ◽  
G. Farkas ◽  
Antonnette A. Wieneke ◽  
R. J. Gilbert
Keyword(s):  
Staphylococcus Aureus ◽  
Ambient Temperature ◽  
Uniform Distribution ◽  
Food Poisoning ◽  
Growth And Survival ◽  
Selective Media ◽  
Rate Of Spread

SUMMARYThe growth of an enterotoxin A producing strain ofStaphylococcus aureusin corned beef was investigated. In the inoculated 6 lb. canned product the bacteria spread throughout the meat and attained high numbers. The rate of spread of the organisms was related to the temperature and length of storage of the cans and the numbers of bacteria inoculated. Cans which had been stored for more than four months showed high counts of the bacteria throughout the meat. It was noted that with the long term contaminated product counts ofS. aureuson some selective media may give falsely low results.Numbers ofS. aureuson meat inoculated by handling after removal from the can were initially extremely variable. More uniform distribution and higher counts were attained only if the meat was exposed for some hours at ambient temperature or above. The significance of the results to the investigation of outbreaks of food poisoning suspected of being associated with canned corned beef is discussed.

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