A SELECTIVE PLATING AGAR FOR DIRECT ENUMERATION OF SALMONELLA IN ARTIFICIALLY CONTAMINATED DAIRY PRODUCTS1

1974 ◽  
Vol 37 (8) ◽  
pp. 441-444 ◽  
Author(s):  
R. H. Reamer ◽  
R. E. Hargrove ◽  
F. E. McDonough
Keyword(s):  
Dairy Products ◽  
Agar Medium ◽  
Cottage Cheese ◽  
Selective Agent ◽  
Surrounding Area ◽  
Observable Effect ◽  
Naturally Occurring ◽  
Dry Milk ◽  
Colony Color ◽  
Selective Plating

A selective plating medium was developed that allows direct enumeration of salmonellae in dairy products such as nonfat dry milk, and Cheddar and cottage cheese. The agar medium developed was a modification of the Lysine-Iron-Cystine broth of Hargrove et al., 1971. Strains of species of the genera Escherichia, Enterobacter, Citrobacter, Proteus, Shigella, Pseudomonas, and Bacillus were easily differentiated from salmonellae by colony color and color of surrounding area or absence of growth. The antibiotic, novobiocin, used as a selective agent, inhibited growth of some Proteus, Shigella, and Escherichia; however the antibiotic was most effective against Bacillus, without having any observable effect on salmonellae. The medium was sufficiently sensitive and selective to permit detection of as few as 1–2 salmonellae per gram of product in the presence of naturally occurring bacteria and should be of considerable value in following the Salmonella content of artificially contaminated foods during processing and also during storage.

Improved Microbiological Assay for Penicillin Residues in Milk and Dairy Products

1978 ◽  
Vol 61 (4) ◽  
pp. 918-922
Author(s):  
Stanley E Katz ◽  
Carol A Fassbender
Keyword(s):  
Phosphoric Acid ◽  
Dairy Products ◽  
Microbiological Assay ◽  
Base Layer ◽  
Cottage Cheese ◽  
Cream Cheese ◽  
Dry Milk ◽  
Nonfat Dry Milk ◽  
Consistent Measurement ◽  
Milk And Dairy Products

Abstract The microbiological assay for penicillin residues in milk was improved. Acidification of milk with phosphoric acid to pH 4.5, centrifugation to remove precipitated proteinaceous matter, adjustment of pH to 6.0, a second centrifugation, and the use of a 2% agar base layer resulted in the consistent measurement of 0.01 unit penicillin activity/ml milk. Sarcina lutea was used as the assay organism. Recoveries in milk averaged 94%, in nonfat dry milk 84%, in cottage cheese 97%, and in cream cheese 94%.

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 CHILDREN’S FOOD PREFERENCES INCLUDED AND OFFERED IN THE „SCHOOL SCHEME”

2018 ◽  
Vol XX (6) ◽  
pp. 262-266
Author(s):  
Sławomir Wawrzyniak ◽  
Krystyna Krzyżanowska
Keyword(s):  
Primary School ◽  
Primary Schools ◽  
Dairy Products ◽  
Fruits And Vegetables ◽  
Food Preferences ◽  
Sweet Pepper ◽  
Cottage Cheese ◽  
School Teachers ◽  
Primary School Teachers

The aim of the studies was to gather the primary school teachers’ opinion about the „School Scheme” and its effectiveness, as well as children’s food preferences and the reasons, why some of the schools didn’t take part in the program. The empiric studies were conducted in 2017 and 6,413 teachers from primary schools took part in them. The results show that students prefer to eat fruits than vegetables. If some of them chose vegetables, they ate tomatoes, radish, carrot rather than kohlrabi or sweet pepper. When it comes to dairy products, they took: milk and cottage cheese. Some of the Polish schools didn’t take part in the program, because they claim not to have enough suitable place to store fruits and vegetables at their entities and children’s parents weren’t interested in that matter.

scholarly journals Raw milk consumption and health

2015 ◽  
Vol 143 (1-2) ◽  
pp. 87-92 ◽  
Author(s):  
Anka Popovic-Vranjes ◽  
Milka Popovic ◽  
Marija Jevtic
Keyword(s):  
Dairy Products ◽  
Raw Milk ◽  
Cottage Cheese ◽  
Human Consumption ◽  
Microbiological Analysis ◽  
Unpasteurized Milk ◽  
Thermally Processed ◽  
Bacteriological Testing ◽  
Foodborne Outbreaks ◽  
Milk And Dairy Products

Contrary to the safe practices of milk pasteurization or sterilization, which effectively reduce foodborne outbreaks incidence associated with raw milk and dairy products use, outbreaks caused by such products continue to occur. Despite this fact, a worldwide movement advocating for the rights of raw milk and cheese selling and consumption, due to their specific nutritive characteristics, has strengthened significantly in recent years. Traditional agricultural manufacturers from Serbia still sell products related to thermally unprocessed milk, such as cottage cheese and raw cream. In AP Vojvodina during the period of 1981-2010 a total of 179 foodborne outbreaks were reported, where the incriminated cause of the outbreak were milk or diary. In 126 (70.39%) outbreaks, totaling 2276 sick individuals and one casualty, it was confirmed that the incriminated food was from the group of dairy products. In 48 instances (26.82%), bacteriological tests confirmed that milk and dairy products were excluded as the outbreak causes, while in another 5 (2.79%) outbreaks, microbiological analysis of food failed to confirm any relation to the actual epidemiological instances. In some cases, bacteriological testing of incriminated foods was not possible. In the cases of outbreaks associated with the consumption of milk and dairy products, traditional raw milk products were cited as being used. Consumption of unpasteurized milk and cheese represents public health threat. National and international rules ensuring use of safe products for human consumption have to set rules of trade of thermally processed milk and products on the market.

Dry Rehydratable Films for Enumeration of Coliforms and Aerobic Bacteria in Dairy Products: Collaborative Study

1989 ◽  
Vol 72 (2) ◽  
pp. 312-318
Author(s):  
Michael S Curiale ◽  
Paul Fahey ◽  
Terrance L Fox ◽  
J Sue Mcallister
Keyword(s):  
Dairy Products ◽  
Collaborative Study ◽  
Ice Cream ◽  
Food Products ◽  
Aerobic Bacteria ◽  
Chocolate Milk ◽  
Coliform Count ◽  
Dry Milk ◽  
Better Than ◽  
Dry Film

Abstract A collaborative study was conducted to compare proposed dry-film plating methods, using aerobic count plates and coliform count plates, to standard agar plating methods for quantifying aerobic bacteria and coliforms in dairy products. In this study, 5 food products (chocolate milk, pasteurized cheese, nonfat dry milk, evaporated milk, and vanilla ice cream), selected as representative dairy products, were analyzed by 11 collaborating laboratories. The results indicate that the dry-film plating methods are equivalent to or better than the agar plating methods. The aerobic count and coliform count dry-film plating methods have been adopted official first action.

Comparison of a simple butterfat agar medium with other media used for isolation and enumeration of lipolytic bacteria from dairy products

1987 ◽  
Vol 54 (3) ◽  
pp. 413-420 ◽  
Author(s):  
Arthur W. Shelley ◽  
Hilton C. Deeth ◽  
Ian C. MacRae
Keyword(s):  
Melting Point ◽  
Bacterial Growth ◽  
Dairy Products ◽  
Agar Medium ◽  
Nutrient Agar ◽  
Nutrient Agar Medium

SummaryA nutrient agar medium containing 0·1 % of a low melting point fraction of butterfat was shown to be suitable for detection, enumeration and isolation of lipolytic bacteria from milk. Bacterial growth was not inhibited by the butterfat and lipolytic reactions were clearly visible and easily interpreted. Lipolytic counts on the butterfat agar compared favourably with lipolytic counts obtained with other commonly used media.

scholarly journals Note on Non-applicability of the AOAC Xanthydrol Test for Urea When Applied to Non-Fat Dry Milk

1969 ◽  
Vol 52 (5) ◽  
pp. 1049-1049
Author(s):  
C C Freeman
Keyword(s):  
Naturally Occurring ◽  
Dry Milk

Abstract The AOAC xanthydrol test for urea has been found to be non-applicable for the analysis of non-fat dried milk because the level of urea naturally occurring in the dried solids interferes.

scholarly journals Characteristics of Commercial Nonfat Dry Milk for Cottage Cheese

1961 ◽  
Vol 44 (5) ◽  
pp. 833-843 ◽  
Author(s):  
H.E. Randolph ◽  
T. Kristoffersen
Keyword(s):  
Cottage Cheese ◽  
Dry Milk ◽  
Nonfat Dry Milk

scholarly journals Concurrent Quantitation of Total Campylobacter and Total Ciprofloxacin-Resistant Campylobacter Loads in Rinses from Retail Raw Chicken Carcasses from 2001 to 2003 by Direct Plating at 42°C

2005 ◽  
Vol 71 (8) ◽  
pp. 4510-4515 ◽  
Author(s):  
Ramakrishna Nannapaneni ◽  
Robert Story ◽  
Keith C. Wiggins ◽  
Michael G. Johnson
Keyword(s):  
Detection Limit ◽  
Agar Medium ◽  
Lethal Dose ◽  
Sampling Period ◽  
Selective Isolation ◽  
Direct Plating ◽  
First Report ◽  
Naturally Occurring

ABSTRACT This is the first report on the use of a normally lethal dose of ciprofloxacin in a Campylobacter agar medium to kill all ciprofloxacin-sensitive Campylobacter spp. but allow the selective isolation and quantitation of naturally occurring presumptive ciprofloxacin-resistant Campylobacter CFU in rinses from retail raw chicken carcasses (RTCC). Thermophilic-group total Campylobacter CFU and total ciprofloxacin-resistant Campylobacter CFU (irrespective of species) were concurrently quantified in rinses from RTCC by direct plating of centrifuged pellets from 10 or 50 ml out of 400-ml rinse subsamples concurrently on Campylobacter agar and ciprofloxacin-containing Campylobacter agar at 42°C (detection limit = 0.90 log10 CFU/carcass). For 2001, 2002, and 2003, countable Campylobacter CFU were recovered from 85%, 96%, and 57% of RTCC, while countable ciprofloxacin-resistant Campylobacter CFU were recovered from 60%, 59%, and 17.5% of RTCC, respectively. Total Campylobacter CFU loads in RTCC rinses ranged from 0.90 to 4.52, 0.90 to 4.58, and 0.90 to 4.48 log10 CFU/carcass in 2001, 2002, and 2003, respectively. Total ciprofloxacin-resistant Campylobacter CFU loads in RTCC rinses ranged from 0.90 to 4.06, 0.90 to 3.95, and 0.90 to 3.04 log10 CFU/carcass in 2001, 2002, and 2003, respectively. Overall, total Campylobacter loads of 0.90 to 2.0, 2 to 3, 3 to 4, 4 to 5 log10 CFU/carcass, respectively, were recovered from 16%, 32%, 26%, and 5% of RTCC tested over the 2-year sampling period. For the same period, total ciprofloxacin-resistant Campylobacter loads of 0.90 to 2.0, 2 to 3, 3 to 4, and 4 to 5 log10 CFU/carcass, respectively, were recovered from 24%, 11%, 7%, and 0.2% of RTCC tested. There was a steady decline in total Campylobacter and total ciprofloxacin-resistant Campylobacter loads in RTCC rinses from 2001/2002 to 2003.

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