Staphylococcal Enterotoxin A and C Production with Various Sugars as Energy Source1

1978 ◽  
Vol 41 (8) ◽  
pp. 643-646 ◽  
Author(s):  
M. J. WOODBURN ◽  
T. N. MORITA ◽  
K. ROWE ◽  
S. S. PARK
Keyword(s):  
Staphylococcus Aureus ◽  
Growth Rate ◽  
Casein Hydrolysate ◽  
Staphylococcal Enterotoxin ◽  
Staphylococcal Enterotoxin A ◽  
Added Sugar ◽  
Measured Addition

One percent added sugar (sucrose, maltose, lactose, glucose and glucose plus fructose) to casein hydrolysate (NAK) medium with or without starch or low methoxyl pectin did not significantly affect enterotoxin C production but did significantly decrease the pH at 12 and 24 h. The increased viscosity of colloidally thickened media resulted in decreased aeration in shaken cultures and decreased quantities of enterotoxin C. Sugars tested did not differ practically in their effects on the parameters of multiplying Staphylococcus aureus 361 and 265-1 which were measured. Addition of 1% of glucose, sucrose, or maltose prevented the decreased growth rate observed when strain 265-1 was grown in 20% O2 + 80% N2 instead of air.

Enzyme Immunoassay for Staphylococcal Enterotoxin A

1980 ◽  
Vol 63 (5) ◽  
pp. 1138-1143
Author(s):  
Peter E Kauffman
Keyword(s):  
Staphylococcus Aureus ◽  
Alkaline Phosphatase ◽  
Enzyme Immunoassay ◽  
Staphylococcal Enterotoxin ◽  
Staphylococcal Enterotoxin A ◽  
Cross Reactions ◽  
Staphylococcal Enterotoxins ◽  
Staphylococcus Aureus Cowan

Abstract An enzyme immunoassay procedure specifying alkaline phosphatase-labeled enterotoxin A was used to determine enterotoxin in standardized solutions and food extracts. Staphylococcus aureus Cowan 1 cells were used to separate unbound from antibody-bound enterotoxin. The method is sensitive to 2 ng enterotoxin A/mL; cross reactions with other staphylococcal enterotoxins did not interfere with the specificity. The method is sensitive and precise enough to serve as a reliable alternative to radioimmunoassay for enterotoxin A.

Growth and Production of Enterotoxin by Staphylococcus aureus S-6 in Soy Proteins and Soy-Supplemented Beef and Pork Sausage

1978 ◽  
Vol 41 (10) ◽  
pp. 794-797 ◽  
Author(s):  
S. E. CRAVEN ◽  
L. C. BLANKENSHIP ◽  
A. J. MERCURI
Keyword(s):  
Staphylococcus Aureus ◽  
Soy Protein ◽  
Staphylococcal Enterotoxin ◽  
Soy Proteins ◽  
Staphylococcal Enterotoxin B ◽  
Soy Protein Concentrate ◽  
Staphylococcal Enterotoxin A ◽  
Pork Sausage ◽  
Generation Times ◽  
Isolated Soy Protein

The effect of three commercial soy proteins on growth and production of enterotoxin by Staphylococcus aureus S-6 was determined. Sterile isolated soy protein (ISP), soy protein concentrate (SPC), and textured soy protein (TSP) were adjusted to 20% protein by diluting with sterile nutrient medium, inoculated with S. aureus S-6 and incubated at 37 C. Generation times of S. aureus S-6 in ISP, SPC, and TSP were 41, 38, and 33 min, respectively. At 48 h, log 8.4 – 8.5 organisms/g were found in the soy products, and staphylococcal enterotoxin A (SEA) and staphylococcal enterotoxin B (SEB) were produced. Each of three hydrated soy protein products was added to ground beef or pork sausage to attain 20% (wt/wt) and cooked to 71 C. Each product was then inoculated and incubated at 37 C. Generation times of S. aureus S-6 did not differ significantly for any beef-soy or pork-soy samples compared to beef or pork sausage controls. Production of SEB (12–72 h) was similar in most beef-soy and pork-soy samples compared to controls, but was significantly lower in the beef-SPC product and beef-TSP and significantly higher in pork-ISP. Small quantities of SEA were produced in beef, beef-soy, pork, and pork-soy samples. Possibly reduction of enterotoxin production in some meat-soy samples was due to outgrowth and competition by spore contaminants of the soy proteins that survived cooking. Production of SEB in all beef-soy and beef control samples was not significantly different when raw samples were autoclaved before inoculation.

scholarly journals Staphylococcus aureus and Staphylococcal Enterotoxin A in Breaded Chicken Products: Detection and Behavior during the Cooking Process

2006 ◽  
Vol 72 (11) ◽  
pp. 7057-7062 ◽  
Author(s):  
Olimpia Pepe ◽  
Giuseppe Blaiotta ◽  
Francesca Bucci ◽  
Marilena Anastasio ◽  
Maria Aponte ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Latex Agglutination ◽  
Staphylococcal Enterotoxin ◽  
Staphylococcal Enterotoxin A ◽  
Potential Health ◽  
Cooking Process ◽  
Enterotoxin Genes ◽  
Scale Preparation ◽  
Toxic Shock Syndrome Toxin ◽  
And Behavior

ABSTRACT In this study we examined the presence of Staphylococcus aureus and staphylococcal enterotoxin A (SEA) in 20 industrial breaded chicken products obtained from different retail butchers and supermarket stores in Italy. The levels of contamination in the products analyzed were quite low, although the pH values and water activities (aw) in the samples considered were in ranges favorable for S. aureus growth. As demonstrated by phenotypic and molecular characterization, in spite of the high percentage of coagulase-positive Staphylococcus strains, only three strains could be referred to the species S. aureus. Moreover, all the strains were negative in PCR assays targeting staphylococcal enterotoxin genes (seA to seE, seG to seJ, and seM to seO), as well as the toxic shock syndrome toxin 1 gene, and no SEA was detected in the retail breaded chicken samples analyzed by a reversed passive latex agglutination assay or by Western blotting. Hence, we evaluated the thermal resistance of two strains of SEA-producing S. aureus in a laboratory-scale preparation of precooked breaded chicken cutlets. The heat treatment employed in the manufacture determined the inactivation of S. aureus cells, but the preformed SEA remained active during product storage at 4°C. The presence of the staphylococci and, in particular, of S. aureus in the retail breaded chicken products analyzed is a potential health risk for consumers since the pH and aw values of these kinds of products are favorable for S. aureus growth. The thermal process used during their manufacture can limit staphylococcal contamination but cannot eliminate preformed toxins.

Behaviour and enterotoxin production by Staphylococcus aureus during the manufacture and ripening of raw goats' milk lactic cheeses

1998 ◽  
Vol 65 (2) ◽  
pp. 273-281 ◽  
Author(s):  
CHRISTINE VERNOZY-ROZAND ◽  
ANNIE MEYRAND ◽  
CHRISTINE MAZUY ◽  
MARIE-LAURE DELIGNETTE-MULLER ◽  
GUY JAUBERT ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Monoclonal Antibodies ◽  
Sandwich Elisa ◽  
Final Concentration ◽  
Staphylococcal Enterotoxin ◽  
Initial Population ◽  
Staphylococcal Enterotoxin A ◽  
Staph Aureus ◽  
Enterotoxin Production ◽  
Elisa Technique

To study the possible presence of staphylococcal enterotoxin A in raw goats' milk lactic cheese, milk was inoculated with an enterotoxigenic Staphylococcus aureus strain to a final concentration of 4, 5 and 6 log(cfu/ml). Cheese was prepared following industrial specifications and ripened for 42 d. Detection of the enterotoxins was by the Vidas Staph enterotoxin test (BioMérieux) and by an indirect double-sandwich ELISA technique using anti-enterotoxin monoclonal antibodies. Staphylococcal counts declined markedly after draining, and by the end of ripening they had disappeared from some cheeses. In contrast, aerobic mesophilic organisms grew well. The level of staphylococcal enterotoxin A recovered varied from 1 to 2·5 ng/g cheese made with an initial population of 105 or 106 cfu/ml. Only traces of enterotoxin A (0·5 ng/g) were detected in cheeses made with the lowest Staph. aureus inoculum used in this study. Enterotoxin A was also detected in cheeses from which Staph. aureus had disappeared.

Microbiological quality aspects of ready-to-eat foods with focus on antibiotic resistance and biofilm formation abilities of foodborne bacteria

2021 ◽  
Vol 50 (3) ◽  
pp. 433-441
Author(s):  
D. Aksoy
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Microbiological Quality ◽  
Staphylococcal Enterotoxin ◽  
Penicillin G ◽  
Aerobic Bacteria ◽  
Staphylococcal Enterotoxin A ◽  
Quality Aspects

AbstractIn this study, microbiological quality of 93 ready-to-eat food products was determined by enumeration of total aerobic bacteria and members of Enterobacteriaceae. Presence of Staphylococcus aureus and Listeria monocytogenes in the products were also investigated. Aerobic colony counts were between 1.9 × 102–3.4 × 108 CFU g−1 for 84.9% and Enterobacteriaceae counts were between 2 × 102 and 6.7 × 106 CFU g−1 for 43% of the samples. S. aureus was detected in 7.5% of the samples, but L. monocytogenes was not detected in any sample. 72.9% of the Enterobacteriaceae isolates showed resistance to at least one antibiotic tested, and 5 among the S. aureus isolates were found to be resistant to penicillin G and 2 against methicillin. Four S. aureus isolates produced only Staphylococcal enterotoxin A and 1 isolate produced both Staphylococcal enterotoxin A and B. Biofilm experiments revealed biofilm formation on polystyrene for 95.8%, 87.5%, and 91.6% of Enterobacteriaceae isolates at 4 °C, 22 °C, and 37 °C, respectively, whereas all S. aureus isolates formed biofilm at all temperatures.

Staphylococcal Enterotoxin A Gene–Carrying Staphylococcus aureus Isolated from Foods and Its Control by Crude Alkaloid from Papaya Leaves

2014 ◽  
Vol 77 (11) ◽  
pp. 1992-1997 ◽  
Author(s):  
LITA HANDAYANI ◽  
DIDAH NUR FARIDAH ◽  
HARSI D. KUSUMANINGRUM
Keyword(s):  
Staphylococcus Aureus ◽  
Food Poisoning ◽  
Dry Weight ◽  
Raw Milk ◽  
Staphylococcal Enterotoxin ◽  
Staphylococcal Enterotoxin A ◽  
Assisted Extraction ◽  
Ultrasonic Assisted ◽  
Broth Macrodilution ◽  
Ultrasonic Assisted Extraction

Staphylococcus aureus is a known pathogen causing intoxication by producing enterotoxins in food. Staphylococcal enterotoxin A is one of the enterotoxins commonly implicated in staphylococcal food poisoning. The ability of crude alkaloid extract from papaya leaves to inhibit the growth of S. aureus and staphylococcal enterotoxin A synthesis was investigated. Staphylococcal enterotoxin A gene–carrying S. aureus was isolated from raw milk and ready-to-eat foods. Crude alkaloid was extracted from ground, dried papaya leaves using ultrasonic-assisted extraction, and a MIC of the alkaloid was determined by the broth macrodilution method. Furthermore, S. aureus isolate was exposed to the crude alkaloid extract at one- and twofold MIC, and the expression of sea was subsequently analyzed using a quantitative reverse transcription real-time PCR. Ten isolates of S. aureus were obtained, and nine of those isolates were sea carriers. The yield of crude alkaloid extract was 0.48 to 1.82% per dry weight of papaya leaves. A MIC of crude alkaloid to S. aureus was 0.25 mg/ml. After exposure to the alkaloid at 0.25 and 0.5 mg/ml for 2 h, a significant increase in cycle threshold values of sea was observed. The sea was expressed 29 and 41 times less when S. aureus was exposed to crude alkaloid at one- and twofold MIC, respectively. This study revealed that crude alkaloid of papaya leaves could control staphylococcal enterotoxin A gene–carrying S. aureus by suppressing the expression of sea, in addition to the ability to inhibit the growth of S. aureus. The expression of sea was successfully quantified.

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