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.

Most Probable Number Method for Isolation and Enumeration of Staphylococcus aureus in Foods: Collaborative Study

1987 ◽  
Vol 70 (1) ◽  
pp. 35-38 ◽  
Author(s):  
Gayle A Lancette ◽  
John Lanier
Keyword(s):  
Staphylococcus Aureus ◽  
Collaborative Study ◽  
Most Probable Number ◽  
Sodium Pyruvate ◽  
Probable Number ◽  
Milk Samples

Abstract Enumeration of Staphylococcus aureus in foods was collaboratively studied by comparing the present AOAC final action method, 46.062, which uses trypticase soy broth with 10% NaCl to a proposed replacment method which uses the same broth with 1% sodium pyruvate added. Fifteen collaborators analyzed uninoculated samples of milk, tuna salad, and ground turkey, as well as samples inoculated with low (102 cells/g), middle (104 cells/g), and high (106 cells/g) levels of S. aureus. The samples were frozen immediately to maintain the inoculated level of S. aureus in the food. A different strain of S. aureus was used for each food; heat-stressed S. aureus cells were used to inoculate the milk samples. The pyruvate-amended broth significantly (α = 0.05) increased enumeration of low, middle, and high levels of S. aureus from milk and ground turkey, and from tuna salad at middle and high levels. The pyruvate-amended media method has been adopted official first action to replace method 46.062

scholarly journals Comparison of media and methods for countingClostridium perfringensin poultry meat and further-processed products

1980 ◽  
Vol 84 (1) ◽  
pp. 151-158 ◽  
Author(s):  
B. W. Adams ◽  
G. C. Mead
Keyword(s):  
Egg Yolk ◽  
Poultry Meat ◽  
Most Probable Number ◽  
Similar Species ◽  
Good Growth ◽  
Probable Number ◽  
Direct Plating ◽  
Confirmatory Tests ◽  
Processed Products ◽  
Reference Strains

SUMMARYA Most Probable Number (MPN) method involving Differential Reinforced Clostridial Medium followed by streaking on Willis & Hobbs medium was com pared with direct plating of samples on Tryptose-Suiphite-Cycloserine agar with out egg yolk, and two forms of Oleandomycin-Polymyxin-Suiphadiazine-Per fringens agar, one being prepared from a commercial, dehydrated product.With skin samples taken from chicken carcasses at different stages of processing, the three direct plating media gave similar counts ofCl. perfringenswhereas results obtained with the MPN method were consistently lower.Although counts ofCl. perfringensfrom various further processed products were usually < 10/g, the three plating media showed similar specificity for this organism.All media supported good growth of reference strains ofClostridium perfringensbut it was founsi that physiologically similar species, includingCl. absonum, Cl. paraperfringens and Cl. perenne alsogrew uninhibited in these media and produced colonies identical with those ofCl. perfringens, thus indicating the need for confirmatory tests forCl. perfringenswhen examining natural samples.

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.

Enumeration and Confirmation of Bacillus cereus in Foods: Collaborative Study

1980 ◽  
Vol 63 (3) ◽  
pp. 581-586 ◽  
Author(s):  
Gayle A Lancette ◽  
Stanley M Harmon ◽  
◽  
D Brooks ◽  
R Bryant ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Collaborative Study ◽  
Population Level ◽  
Egg Yolk ◽  
High Population ◽  
Most Probable Number ◽  
Probable Number ◽  
Direct Plating ◽  
Plating Technique ◽  
Mashed Potatoes

Abstract A collaborative study was conducted in 15 laboratories to evaluate 2 different techniques for enumerating Bacillus cereus in foods. A direct plating technique using mannitol-egg yolk-polymyxin agar and a most probable number (MPN) technique using trypticase-soy-polymyxin broth were compared for the enumeration of high and low populations of B. cereus in mashed potatoes. The collaborative results showed that the overall mean recovery obtained with the low population level was essentially the same by both techniques. However, the overall mean recovery was significantly higher by the direct plating technique at the high population level. A statistical evaluation of the data also showed that the direct plating technique had better repeatability and reproducibility than did the MFN technique at both the high and low population levels. These results suggest that the MPN technique is suitable for examining foods containing low populations of B. cereus, but that the direct plating technique is preferable for foods that contain a high population of this organism. The confirmatory technique used in the proposed method is reliable for presumptive identification of isolates as B. cereus. The method has been adopted as official first action.

Use of Iron Milk Medium for Enumeration of Clostridium perfringens

1982 ◽  
Vol 65 (5) ◽  
pp. 1129-1133 ◽  
Author(s):  
William D St John ◽  
Jack R Matches ◽  
Marleen M Wekell
Keyword(s):  
Clostridium Perfringens ◽  
Incubation Time ◽  
Incubation Temperature ◽  
Egg Yolk ◽  
Most Probable Number ◽  
Biochemical Tests ◽  
Probable Number ◽  
Large Numbers ◽  
Whole Milk ◽  
Short Incubation Time

Abstract A simple iron milk medium was used for isolation and enumeration of Clostridium perfringens from soil, sludge, and water samples. The whole milk contained only iron powder as a reducing agent; no other inhibitors were added. The iron milk most probable number (MPN) procedure was compared with 4 plating media: sulfite-polymyxin-sulfadiazine, Shahidi-Ferguson perfringens, tryptose-sulfite- cycloserine (both with and without egg yolk), and tryptone-sulfite-neomycin. The selectivity of the iron milk relies solely on the rapid growth of C. perfringens at 45°C and the stormy fermentation reaction within 18 h. Isolates were confirmed as C. perfringens by standard biochemical tests. The iron milk MPN procedure compared very well with the 4 plating media tested. Selectivity of incubation temperature, short incubation time, and ease of identification by the characteristic stormy fermentation make this method ideal for enumerating C. perfringens from large numbers of samples.

scholarly journals Evaluation of Two Direct Plating Methods Using Nonradioactive Probes for Enumeration of Vibrio parahaemolyticus in Oysters

2001 ◽  
Vol 67 (2) ◽  
pp. 721-724 ◽  
Author(s):  
J. A. Gooch ◽  
A. DePaola ◽  
C. A. Kaysner ◽  
D. L. Marshall
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Most Probable Number ◽  
Mobile Bay ◽  
Probable Number ◽  
Direct Plating ◽  
Hemolysin Gene ◽  
Highly Correlated ◽  
Species Specific ◽  
Labeled Probe ◽  
Zero Time

ABSTRACT Oysters (Crassostrea virginica) were collected monthly from May 1998 to April 1999 from Mobile Bay, Ala., and analyzed to determine Vibrio parahaemolyticus densities at zero time and after 5, 10, and 24 h of postharvest storage at 26°C. After 24 h of storage at 26°C, oysters were transferred to a refrigerator at 3°C and then analyzed 14 to 17 days later. TheV. parahaemolyticus numbers were determined by the most-probable-number procedure using alkaline phosphatase-labeled DNA probe VPAP, which targets the species-specific thermolabile hemolysin gene (tlh), to identify suspect isolates (MPN-VPAP procedure). Two direct plating methods, one using a VPAP probe (Direct-VPAP) and one using a digoxigenin-labeled probe (Direct-VPDig) to identify suspect colonies, were compared to the MPN-VPAP procedure. The results of the Direct-VPAP and Direct-VPDig techniques were highly correlated (r = 0.91), as were the results of the Direct-VPAP and MPN-VPAP procedures (r = 0.91). The correlation between the Direct-VPDig and MPN-VPAP results was 0.85. The two direct plating methods in which nonradioactive DNA probes were used were equivalent to the MPN-VPAP procedure for identification of totalV. parahaemolyticus, and they were more rapid and less labor-intensive.

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.

Precision Parameters for the FDA Shellfish Laboratory Quality Assurance Program for 1973–1989

1995 ◽  
Vol 58 (6) ◽  
pp. 648-650
Author(s):  
JAMES T. PEELER ◽  
THOMAS E. GRAHAM ◽  
LARRY J. MATURIN
Keyword(s):  
Staphylococcus Aureus ◽  
Quality Assurance ◽  
Fecal Coliform ◽  
Quality Assurance Program ◽  
Plate Count ◽  
Most Probable Number ◽  
Probable Number ◽  
Standard Plate Count ◽  
Standard Plate ◽  
The U.S

Precision parameters from four microbiological analytical methods (coliform most probable number [MPN], fecal coliform MPN, Staphylococcus aureus plate count and standard plate count) were computed for the Shellfish Quality Assurance Program of the U.S. Food and Drug Administration (FDA). The pooled reproducibility variance (SR2) for the four methods from 1973 to 1989 were 0.0778, 0.1181, 0.0137, and 0.0087, respectively.

scholarly journals Individual Predisposition to Staphylococcus aureus Colonization in Pigs on the Basis of Quantification, Carriage Dynamics, and Serological Profiles

2014 ◽  
Vol 81 (4) ◽  
pp. 1251-1256 ◽  
Author(s):  
Carmen Espinosa-Gongora ◽  
Jan Dahl ◽  
Anders Elvstrøm ◽  
Willem J. van Wamel ◽  
Luca Guardabassi
Keyword(s):  
Staphylococcus Aureus ◽  
Humoral Response ◽  
Nasal Carriage ◽  
Most Probable Number ◽  
Cross Sectional ◽  
Probable Number ◽  
Content Type ◽  
Luminex Assay ◽  
Nasal Swabs ◽  
Cross Sectional Design

ABSTRACTPrevious research onStaphylococcus aureusin pigs focused on livestock-associated methicillin-resistantS. aureus(MRSA) and had a qualitative cross-sectional design. This study aimed to elucidate the frequency, load, and stability ofS. aureusnasal carriage in pigs over time and investigated possible associations between carriage and immune response. Nasal swabs were collected three times weekly from 480 tagged adult pigs in 20 Danish production farms.S. aureusand MRSA were quantified on selective media by the most-probable-number method. The levels of IgG against 10S. aureusantigens in serum were quantified in selected pigs by a Luminex assay. All the farms were positive forS. aureusand 15 for MRSA, leading to overall prevalences of persistent and intermittent carriers and noncarriers of 24, 52, and 23%, respectively. Carriage frequency and nasal loads were significantly higher on MRSA-positive farms. Logistic-regression modeling revealed the presence of individual pigs characterized by high nasal loads (≥10,000 CFU per swab) and stable carriage regardless of farm- and pen-associated factors. On the other hand, the humoral response was strongly influenced by these environmental factors. The existence of a minority of shedders contributing to maintenance ofS. aureuswithin farms opens up new perspectives on the control of MRSA in pig farming.

Sign in / Sign up

Export Citation Format

Share Document