Un milieu gélosé pour le dénombrement direct de Staphylococcus aureus : milieu au plasma de porc pour S. aureus (PPSA)

1976 ◽  
Vol 22 (11) ◽  
pp. 1603-1611 ◽  
Author(s):  
J-J. Devoyod ◽  
Liliane Millet ◽  
G. Mocquot
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Products ◽  
Agar Medium ◽  
Egg Yolk ◽  
Plasma Medium ◽  
Large Numbers ◽  
Selective Agar ◽  
Coagulase Positive Staphylococci

A selective agar medium (pork plasma medium for S. aureus (PPSA)) enables the direct enumeration of coagulase-positive staphylococci. This medium is based on the Baird-Parker agar without egg yolk and is supplemented with pig plasma. Colonies of Staphylococcus aureus are surrounded by a halo of precipitated fibrin. When foods such as dairy products contain large numbers of egg yolk – negative strains of S. aureus, the PPSA agar has the advantage over egg yolk containing media such as Baird-Parker agar that fewer suspect colonies have to be confirmed.

Effect of Thawing on Growth of Staphylococcus Aureus in Frozen Convenience Food Items1

1975 ◽  
Vol 38 (6) ◽  
pp. 337-339 ◽  
Author(s):  
K. OSTOVAR ◽  
MARGARET J. BREMIER
Keyword(s):  
Staphylococcus Aureus ◽  
Egg Yolk ◽  
Frozen Foods ◽  
Convenience Food ◽  
Food Items ◽  
Poultry Products ◽  
Selective Agar ◽  
Seafood Products ◽  
Agar Media ◽  
Coagulase Positive Staphylococci

The appearance of convenience food items in the supermarkets and their consumption by wide segments of population has increased in recent years, and hence a study was done on presence of Staphylococcus aureus in these items and possible growth of the organism during defrosting of the foods. Using different selective agar media (Baird-Parker, Vogel-Johnson, Tellurite-polymyxin-egg yolk. and Mannitol-salt), various commercially available food items were examined. All suspected cultures were confirmed by coagulase test and Gram stain. Their enterotoxigenicity was also examined. Thawing the products at room temperature for 12 h generally resulted in a two-log increase in S. aureus population. Presence of S. aureus was observed in 18.3% of beef and poultry products; 12.5% of seafood products; and 8.3% of ready-to-eat frozen desserts. Most isolates produced types A or B enterotoxins. Of four selective agar media used. Baird-Parker was most efficient in isolating coagulase-positive staphylococci from frozen foods.

Assessment of different selective agar media for enumeration and isolation ofListeriafrom dairy products

1988 ◽  
Vol 55 (4) ◽  
pp. 579-583 ◽  
Author(s):  
Lucas Dominguez ◽  
José Francisco Fernández ◽  
Victor Briones ◽  
José Luis Blanco ◽  
Guillermo Suárez
Keyword(s):  
Dairy Products ◽  
Agar Medium ◽  
Raw Milk ◽  
Superior Performance ◽  
Direct Plating ◽  
Selective Agar ◽  
Natural Microflora ◽  
Agar Media ◽  
The Difference ◽  
Better Than

SummaryDifferent selective agar media were compared for the recovery and isolation of five species ofListeriafrom raw milk and cheese. The selective media examined were Beerens medium, MacBride medium and that described by Dominguezet al.(1984) with 6 mg/1 acriflavine, listeria selective agar medium (LSAM), and LSAM with 12 mg/1 acriflavine (LSAM × 2A); a non-selective yeast glucose Lemco agar was included for comparison. When the difference between listeria and the natural microflora of raw milk and cheese was 102cfu/ml, listeria could be isolated by direct plating on all media tested. When it was lower than 103–104cfu/ml, listeria were isolated by direct plating only on LSAM and LSAM × 2A. When the difference was greater than 104cfu/ml, a previous enrichment was necessary to isolate them. LSAM and LSAM × 2A media performed better than the other media tested for isolating listeria by direct plating and improved their isolation from dairy products. This superior performance was evaluated by the ability of these media to support colony formation of different species ofListeriatested, the easy recognition of these colonies from those formed by other microorganisms and by their capacity to inhibit the natural microflora of these foods.

scholarly journals Antimicrobial resistance of bacterial isolates from dierent dairy products and their emergence in the food chain

2018 ◽  
Vol 11 (1) ◽  
pp. 45-57
Author(s):  
É. György ◽  
É. Laslo
Keyword(s):  
Risk Factors ◽  
Antibiotic Resistance ◽  
Foodborne Pathogens ◽  
Dairy Products ◽  
Preventive Measures ◽  
Agar Medium ◽  
Bacterial Isolates ◽  
E Coli ◽  
Selective Agar ◽  
Overall Resistance

Abstract The antibiotic resistance of foodborne pathogens represents a healthcare concern globally. This phenomenon has an increasing impact on medicine and economy. A total of 26 spoilage and pathogenic bacterial isolates originating from different dairy products have been screened against eight different antibiotics. Based on the type of the selective agar medium used for their isolation, the isolates were: five staphylococci isolates, six Vibrio isolates, two Pseudomonas sp. isolates, three Salmonella isolates, five E. coli isolates, and five coliform isolates. The overall resistance to the tested antimicrobials of the bacterial isolates was 31.73%, the majority being susceptible. Based on the results, there are isolates with multiple antibiotic patterns that can be possible risk factors and may call for preventive measures.

A Simple Medium for Isolation of Coagulase-Positive Staphylococci in a Single Step

1982 ◽  
Vol 45 (3) ◽  
pp. 218-222 ◽  
Author(s):  
LEONIE MINTZER-MORGENSTERN ◽  
ELIY AHU KATZENELSON
Keyword(s):  
Agar Medium ◽  
Brain Heart Infusion ◽  
Egg Yolk ◽  
Food Samples ◽  
Selective Medium ◽  
Single Step ◽  
Isolation And Identification ◽  
Complete Reversal ◽  
Simple Medium ◽  
Coagulase Positive Staphylococci

An agar medium containing NaCl, egg yolk and tellurite for selective quantitative isolation of coagulase-positive staphylococci from food was developed. Isolation and identification of the staphylococci was achieved in a single step. A properly diluted food sample was spread over the medium and incubated for 24 h at 42 C. Coagulase-positive staphylococci appeared as small grey to dark-grey colonies surrounded by a dense white opacity. Coagulase-negative bacteria which, at times, grow on this medium, did not produce this reaction. The identification on this selective medium of isolates from 683 different food samples as coagulase-positive staphylococci was subsequently confirmed by the coagulase test. Comparative titrations of 29 various coagulase-positive staphylococcus strains on both the selective medium and nutrient agar yielded nearly identical titers. The growth of heat-stressed staphylococci was inhibited by the selective medium. Complete reversal of the inhibition was achieved by a 3-h pre-incubation in brain heart infusion at 37 C.

Current Resuscitation Methods for Recovery of Stressed Staphylococcus aureus Cells from Foods

1986 ◽  
Vol 49 (6) ◽  
pp. 477-481 ◽  
Author(s):  
GAYLE A. LANCETTE
Keyword(s):  
Staphylococcus Aureus ◽  
Egg Yolk ◽  
Single Step ◽  
Most Probable Number ◽  
Sodium Pyruvate ◽  
Probable Number ◽  
Direct Plating ◽  
Selective Agar

Methods and media used to recover stressed and unstressed Staphylococcus aureus cells from foods are reviewed. Most probable number methods using Trypticase soy broth with 10% salt and 1% sodium pyruvate, a liquid modification of Baird-Parker agar and Giolitti and Cantoni's broth with Tween are discussed. Direct plating media reviewed are Baird-Parker agar, modified Vogel and Johnson agar, egg yolk-free Baird-Parker agar and single-step Staphylococcus selective agar.

STAPHYLOCOCCUS AUREUS AND STAPHYLOCOCCAL FOOD INTOXICATIONS. A REVIEW

1972 ◽  
Vol 35 (4) ◽  
pp. 228-241 ◽  
Author(s):  
T. E. Minor ◽  
E. H. Marth
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Products ◽  
Food Poisoning ◽  
Frozen Foods ◽  
Coagulase Positive Staphylococci

Staphylococcal intoxications involving foods, other than dairy products, have been associated predominantly with meats and bakery items. Outbreaks involving Genoa sausage, corned beef, barbecued chicken, baked ham, fish, pastries, pie fillings, and other foods are reviewed. Because meats have caused food-poisoning outbreaks, commercial samples have been tested for incidence of staphylococcal contamination. Several surveys have revealed that approximately 40% of the samples tested contained coagulase-positive staphylococci. These and other surveys, including studies of some frozen foods, are discussed. Finally, results of research concerning the behavior of staphylococci in several foods are discussed. Investigations on raw, cooked, canned, cured, and smoked meats, and meat pies have been reported in the literature. Studies on pastry and pie fillings have also been conducted and are summarized in this review.

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.

STAPHYLOCOCCUS AUREUS IN COMMERCIALLY PROCESSED FLUID DAIRY AND NON-DAIRY PRODUCTS1

1974 ◽  
Vol 37 (6) ◽  
pp. 329-332
Author(s):  
M. I. Sheikh ◽  
L. O. Luedecke
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Products ◽  
Diffusion Method ◽  
Coagulase Positive Staphylococci ◽  
Gel Diffusion

Eight coagulase-positive staphylococci were isolated from 165 samples of commercially processed fluid dairy products and non-dairy whip. Seven of eight isolates tested for enterotoxigenicity by the mioroslide gel diffusion method did not produce enterotoxin A, B, or C, whereas one isolate produced enterotoxin C. None of the 8 isolates survived heating at 62.8 C for 30 min in raw low-count milk or in sterile milk.

A NEW PROCEDURE FOR THE DETECTION AND ENUMERATION OF COAGULASE-POSITIVE STAPHYLOCOCCI FROM FROZEN SEAFOODS

1966 ◽  
Vol 12 (1) ◽  
pp. 191-198 ◽  
Author(s):  
H. Raj
Keyword(s):  
Liquid Medium ◽  
Solid Medium ◽  
Sorbic Acid ◽  
Egg Yolk ◽  
Confirmatory Test ◽  
Precipitation Reaction ◽  
Large Numbers ◽  
Step Procedure ◽  
Coagulase Positive Staphylococci ◽  
Coagulase Positive Staphylococcus

A two-step procedure in which a new anaerobic liquid medium is used for a presumptive test and a solid medium (staphylococcus medium No, 110 fortified with egg yolk) incubated at 45 °C for a confirmatory test has been developed for the detection and enumeration of coagulase-positive staphylococci in frozen seafoods. The presumptive liquid medium called "Mannitol Salt Sorbic acid broth" provides specific enrichment to coagulase-positive staphylococci even in the presence of large numbers (104–105 cells) of mixed flora common to these foods. The addition of seafood material to the above medium does not affect its selective performance or its sensitivity. Also, the medium is equally efficient in recovering very low numbers of coagulase-positive staphylococcus subjected to freezing, even in the presence of the mixed flora. Incubation at 45 °C in the confirmatory step not only gives an accelerated egg yolk precipitation reaction typical of coagulase-positive staphylococci, but also enhances the specificity of the procedure.

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