Potato-Like Odor of Retail Beef Cuts Associated with Species of Pseudomonas

1986 ◽  
Vol 49 (4) ◽  
pp. 272-273 ◽  
Author(s):  
R. L. DAISE ◽  
E. A. ZOTTOLA ◽  
R. J. EPLEY
Keyword(s):  
Coliform Bacteria ◽  
Plate Count ◽  
Aerobic Bacteria ◽  
Gram Negative ◽  
Consumer Complaints ◽  
Psychrotrophic Bacteria ◽  
Plate Count Agar ◽  
Litmus Milk ◽  
Musty Odor ◽  
Retail Cuts

Retail cuts of beef and hamburger packages from a North Dakota meat processor were examined due to consumer complaints of a strong potato-like or musty odor associated with the meat. Examination for total numbers of aerobic bacteria on plate count agar and for gram-negative psychrotrophic bacteria on crystal violet tetrazolium agar revealed numbers in excess of 108 CFU/g. Numbers of coliform bacteria on violet red bile agar were in excess of 106 CFU/g. Gram-negative rods were isolated and identified. The isolates were characterized by a positive catalase reaction, oxidase production, an oxidative O/F reaction, nonutilization of lactose, liquefication of nutrient gelatin, slight motility, production of acid in litmus milk with decoloration and clotting, nonproduction of indole, and nonreduction of nitrate. The isolate was tentatively identified as a Pseudomonas of undetermined species, probably a variant of either Pseudomonas taetrolens or Pseudomonas perolens.

Comparison between the EC plate count test at 21 °C and an accelerated plate count method for assessing the keeping quality of pasteurized milk

1992 ◽  
Vol 59 (3) ◽  
pp. 431-436 ◽  
Author(s):  
Sarah A. Langford ◽  
Rohan G. Kroll
Keyword(s):  
Plate Count ◽  
Gram Negative ◽  
Rapid Methods ◽  
Pasteurized Milk ◽  
Psychrotrophic Bacteria ◽  
Commercial Interest ◽  
Count Method ◽  
Keeping Quality ◽  
Plate Count Method

The keeping quality of properly refrigerated pasteurized milk and cream is primarily determined by post-pasteurization contamination by Gram-negative psychrotrophic bacteria (Phillips et al. 1981; Schröder et al. 1982). Reliable and rapid methods of assessing the levels of contamination by these organisms are therefore of commercial interest.

INHIBITION OF GROWTH OF AIRBORNE COLIFORMS AND OTHER BACTERIA ON SELECTIVE MEDIA1

1972 ◽  
Vol 35 (3) ◽  
pp. 156-162 ◽  
Author(s):  
Attila K. Stersky ◽  
T. I. Hedrick
Keyword(s):  
Methylene Blue ◽  
Skim Milk ◽  
Enterobacter Aerogenes ◽  
Colony Growth ◽  
Coliform Bacteria ◽  
Plate Count ◽  
Pseudomonas Fragi ◽  
Selective Media ◽  
Standard Plate Count ◽  
Plate Count Agar

Coliforms when sampled from air were inhibited or restricted in growth on regular selective media. For trials, growth on Standard Plate Count Agar ( SPC) was used as 100%. The percentage of colony growth of Escherchia coli and Enterobacter aerogenes on modified selective media or with SPC were respectively as follows: violet red bile/violet red bile (VRB/VRB) (overlay on base) <4, 15; desoxycholate/desoxyeholate (DES/DES) < 1, 17; tergitol/tergitol (TER/TER) 23,49; eosine methylene blue/eosine methylene blue (EMB/EMB) 122, 86; endo/endo (END/END) 40, 104; MacConkey/MacConkey (MAC/MAC) <2, 10; SPC/VRB <2, 22; SPC/DES <2, 23; VRB/SPC 54, 60; TER/SPC 72, 119; EMB/SPC 97, 119; END/SPC 95, 90; 1 VRB: 1 SPC, as overlay and base 14, 50. Recovery percentages of Pseudomonas aeruginosa and Pseudomonas fragi on modified selective media were greater than those of the coliform bacteria. Fewer Serratia marcescens colonies grew on DES or SPC/DES and more grew on the other modified selective media than did coliform colonies. Growth of airborne Salmonella newbrumwick ranged from <1% on SS agar to 118% on MAC/SPC. Aerosolization of coliforms with skim milk compared to distilled water resulted in growth of more colonies on selective media. Desoxycholate, Bile Salts No. 3, Tergitol No. 7, and crystal violet in the media definitely limited growth of airborne coliforms.

Comparison of Media for Determining Temperature Abuse of Fresh Broiler Carcasses Using Impedance Microbiology

1995 ◽  
Vol 58 (10) ◽  
pp. 1124-1128 ◽  
Author(s):  
SCOTT M. RUSSELL ◽  
DANIEL L. FLETCHER ◽  
NELSON A. COX
Keyword(s):  
Broiler Chicken ◽  
Brain Heart Infusion ◽  
Plate Count ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Plate Count Agar ◽  
Processing Plants ◽  
Microbiological Techniques ◽  
The Ideal

Experiments were conducted to determine the ideal medium for detection of temperature abuse of fresh broiler chicken using impedance microbiological techniques. In three separate trials, 15 ready-to-cook broiler chicken carcasses were obtained from the chiller exit of three separate processing plants. Five carcasses were sampled immediately (day 0), 5 carcasses were sampled after temperature abusing at 25°C for 12 h and holding at 3°C for 6 days (temperature abused), and the remaining 5 carcasses were sampled after holding at 3°C for 7 days (day 7 controls). Whole-carcass rinses were diluted by placing 1 ml from each carcass into 9 ml of each of the following media: (1) brain heart infusion broth (BHI), (2) EC broth with 3% added dextrose (ECD), (3) CM medium with 2% added dextrose (CMD), (4) EC broth (EC), and (5) CM medium (CM). The diluted samples were assayed in duplicate at 43°C using impedance microbiological techniques. Once a detection time (DT) was recorded, one ml of the sample was immediately recovered from the module well, diluted to 10−6, 10−7, and 10−8, and spread plated onto plate count agar. Two colonies from each carcass on plates with the highest dilution were randomly selected and identified. Since both gram-positive and gram-negative genera of bacteria were isolated from BHI-cultured carcass rinses and were responsible for changing the impedance of the medium, DTs were variable. EC and ECD media were not suitable for conducting temperature-abuse determinations. Using CMD medium to select for the growth of gram-negative bacteria, specifically E. coli, temperature-abuse determinations were more accurate than using a general medium, such as BHI. CMD appears to be the most effective medium tested to conduct temperature abuse determinations using impedance microbiological techniques.

scholarly journals UJI KELIMPAHAN BAKTERI COLIFORM PADA MAKANAN JAJANAN BAKSO TUSUK YANG DIJUAL DI LINGKUNGAN SDN 82 KUDAMATI DAN SDN 2 TANAH TINGGI AMBON

2019 ◽  
Vol 4 (2) ◽  
pp. 97-101
Author(s):  
Aknes Tahya ◽  
M Kaihena ◽  
Theopilus Watuguly
Keyword(s):  
Elementary School ◽  
Coliform Bacteria ◽  
Plate Count ◽  
Processed Meat ◽  
Snack Food ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Total Plate Count

Background: Snack food is part of food that is inseparable from the community. Snack food consists of various types, one of which is skewer meatballs. Skewers are a type of snack food made from flour and meat that is round and then boiled until cooked, has a savory and chewy taste. One of the bacteria that often contaminates snacks is coliform bacteria. Coliform bacteria is a group of rod-shaped gram negative bacteria. Method: The sample used in the study was skewered meatball samples taken at the location of SDN 82 Kudamati and SDN 2 Tanah Tinggi Ambon. Testing for the presence of coliform bacteria was carried out at the Indonesian Institute of Research and Standardization Laboratory in Ambon. The type of research used is descriptive. Calculation of the number of bacterial colonies using the standard Total Plate Count (TPC). Results: The study showed that the two positive samples contained coliform bacteria with the highest number of coliform bacteria colonies in code A1 1.55 x 105 at location A SDN 82 Kudamati and the lowest at code B1 1.49 x 103 at location B SDN 2 Tanah Tinggi. If compared with SNI for processed meat and chicken products is 1 x 105 colonies / gram, which means the highest number of colonies cannot be consumed. Conclusion: Skewers meatball snacks sold in SDN 82 Kudamati and Ambon Tanah 2 Elementary School 2, positive for coliform bacteria

Changes in the Microflora of Bovine Colostrum During Natural Fermentation

1976 ◽  
Vol 39 (1) ◽  
pp. 27-31 ◽  
Author(s):  
T. L. THOMPSON ◽  
E. H. MARTH
Keyword(s):  
Titratable Acidity ◽  
Bovine Colostrum ◽  
Coliform Bacteria ◽  
Aerobic Bacteria ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Natural Fermentation ◽  
Fecal Streptococci ◽  
Yeasts And Molds

Colostrum from five cows was collected and pooled separately and allowed to ferment naturally for 21 days. During this time the pH decreased and was approximately 4.0 at the end of the fermentation. The titratable acidity of the colostrum at this time was 1.5% or more. Numbers of total aerobic bacteria, fecal streptococci, coliform bacteria, and gram-negative bacteria increased rapidly during the first 2–3 days of fermentation. After several days of reasonable stability, numbers of aerobic bacteria and coliform bacteria declined, whereas numbers of fecal streptococci and gram-negative bacteria remained fairly constant. The number of yeasts and molds increased much more slowly than did those of bacteria and in some instances growth of these organisms was still evident when the fermentation was terminated.

Comparison of Methods for Determining Coliform and Escherichia coli Levels in Apple Cider†

1997 ◽  
Vol 60 (11) ◽  
pp. 1302-1305 ◽  
Author(s):  
TODD M. SILK ◽  
ELLIOT T. RYSER ◽  
CATHERINE W. DONNELLY
Keyword(s):  
Escherichia Coli ◽  
Heterotrophic Bacteria ◽  
High Sensitivity ◽  
Low Ph ◽  
Coliform Bacteria ◽  
Plate Count ◽  
Apple Cider ◽  
E Coli ◽  
Plate Count Agar ◽  
Positive Results

The main objective of this research was to determine the easiest and most reliable media for enumerating coliform bacteria and Escherichia coli levels in apple cider. During the autumn of 1994 a total of 59 apple cider samples were collected directly from 12 cider producers and were assessed for bacterial levels and pH. Plate count agar was used to determine heterotrophic bacteria levels. Coliform levels were determined using three different media: violet red bile agar (VRBA), Petrifilm High Sensitivity Coliform Count Plates (PHSCCP), and Trypticase soy agar with a VRBA overlay (TSA/VRBA) for attempted recovery of coliforms injured by the low pH of the apple cider. Eosin methylene blue agar (EMBA) and Petrifilm E. coli Count Plates were used to screen cider samples for E. coli. Apple cider had an average pH of 3.34 ± 0.08. Heterotrophic bacterial levels ranged from 2.30 to 7.11 log CFU/ml. All cider samples contained coliform bacteria with levels varying greatly; on the different media, we found the following: on VRBA, <1.00 to 4.37 log CFU/ml; on TSA/VRBA, 1.20 to 4.40 log CFU/ml; and on PHSCCP, < 1.00 to 4.56 log CFU/ml. Coliform levels were most easily determined in apple cider by using PHSCCP. However TSA/VRBA proved to be more reliable; coliform detection was significantly (P < 0.05) increased. EMBA was ineffective for screening apple cider for E. coli, with the low pH of the cider producing many false-positive results. E. coli was only recovered by using Petrifilm E. coli Count Plates with one of the 59 samples positive for E. coli (non-O157:H7) at a level of 10 CFU/ml.

Effects of Diacetyl and Carbon Dioxide on Spoilage Microflora in Ground Beef

2002 ◽  
Vol 65 (3) ◽  
pp. 523-527 ◽  
Author(s):  
ANISHA M. WILLIAMS-CAMPBELL ◽  
JAMES M. JAY
Keyword(s):  
Ground Beef ◽  
Plate Count ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Plate Count Agar ◽  
Plate Counts ◽  
Meat Samples ◽  
Spoilage Microflora

The effect of CO2 and diacetyl, alone or in combination, on spoilage microflora in ground beef was determined. Ground beef was treated with 20, 30, or 40% CO2 for 22 days (study I); 20, 50, or 100 μg/g diacetyl for 26 days (study II); or a combination of 20% CO2 and 100 μg/g diacetyl for 40 days (study III). Antimicrobial effectiveness was determined by aerobic plate counts (log10 CFU/g) using plate count agar (total aerobic bacteria), deMan Rogosa Sharpe (MRS) Lactobacillus agar (gram-positive bacteria), MacConkey agar (gram-negative bacteria), pH, and informal organoleptic assessments (by appearance and by odor). In study I, total bacteria and pH increased by day 4 in control meat samples. For all CO2 levels, gram-negative bacteria decreased and gram-positive bacteria increased compared with untreated controls. The pH remained constant for CO2-treated meat. Control samples had an off-odor and a brown appearance, while CO2-treated samples had no off-odor but did have a brown appearance. For samples treated with diacetyl (study II), spoilage was evident by day 7 for samples treated with 0, 20, and 50 μg/g diacetyl for all parameters examined. Ground beef treated with 100 μg/g diacetyl was spoiled on day 12. Diacetyl was detected (by odor) in samples that were treated with 100 μg/g diacetyl and had a brown appearance. Meat samples treated with the combination of CO2 and diacetyl (study III) showed that the addition of diacetyl did not have an additive effect on microbial growth. Combination-treated meat maintained a red appearance and no off-odor. Diacetyl and CO2 could be used in combination to maintain a red color and inhibit spoilage microorganisms.

Improved detection of acid mine water stressed coliform bacteria on media containing catalase and sodium pyruvate

1990 ◽  
Vol 36 (8) ◽  
pp. 544-550 ◽  
Author(s):  
Joseph P. Calabrese ◽  
Gary K. Bissonnette
Keyword(s):  
Mine Water ◽  
Membrane Filtration ◽  
Heterotrophic Bacteria ◽  
Coliform Bacteria ◽  
Plate Count ◽  
Acid Mine Water ◽  
Sodium Pyruvate ◽  
Acid Mine ◽  
Plate Count Agar

Pure culture suspensions of two strains of exponential and stationary phase Escherichia coli exhibited significant reductions in catalase activity following exposure to acid mine water (AMW). The exogenous addition of catalase (500–2000 U) or sodium pyruvate (0.05–5%) to a nonselective recovery medium resulted in enhanced detection (12- to 465-fold) of AMW-stressed E. coli as compared with recovery on the medium lacking these supplements, whereas addition of 3,3′-thiodipropionic acid failed to improve recovery. Additional in vitro experiments utilizing selective M-FC, mT7, and M-Endo media containing 1000 U catalase or 1.0% pyruvate similarly resulted in improved detection of AMW-stressed cells, with the exception of M-Endo containing pyruvate. Appropriately modified media were then used to analyze an AMW-impacted stream by the membrane filtration technique. Addition of catalase, pyruvate, or a combination of both significantly improved recovery of fecal and total coliforms without promoting growth of noncoliforms. Supplementation of plate count agar with pyruvate and (or) catalase enhanced detection of total heterotrophs. These findings suggest that addition of catalase or pyruvate to standard recovery media may improve detection of coliform and total heterotrophic bacteria in AMW-impacted waters. Key words: acid mine water, coliforms, stress.

Comparison of a Rapid ATP Bioluminescence Assay and Standard Plate Count Methods for Assessing Microbial Contamination of Consumers' Refrigerators

2006 ◽  
Vol 69 (10) ◽  
pp. 2534-2538 ◽  
Author(s):  
FUR-CHI CHEN ◽  
SANDRIA L. GODWIN
Keyword(s):  
Microbial Contamination ◽  
Field Studies ◽  
Plate Count ◽  
Culture Methods ◽  
Psychrotrophic Bacteria ◽  
Standard Plate Count ◽  
Plate Count Agar ◽  
Atp Bioluminescence ◽  
Bioluminescence Assay ◽  
Atp Bioluminescence Assay

The feasibility of using an ATP bioluminescence assay for assessing microbial contamination of home refrigerators was evaluated and compared with the standard culture methods. Samples of refrigerator surfaces were collected from 123 households by swabbing an area of 100 cm2 on three locations in the refrigerator with premoisturized sterile swabs. Microbial contaminations were determined by aerobic plate count (APC; incubated at 35°C for 48 h) and psychrotrophic plate count (PPC; incubated at 7°C for 10 days) on plate count agar. The results were compared to the readings from the microbial ATP (mATP) bioluminescence assay. The correlation coefficient (r) between mATP and PPC (r = 0.851) was slightly higher than that between mATP and APC (r = 0.823). Our results indicated a potential discrepancy in the population of mesophilic and psychrotrophic bacteria in the refrigerator samples. Nevertheless, mATP appeared to be a reliable indication of the average of APC and PPC (r = 0.895). The mATP bioluminescence assay would provide a rapid and convenient test for researchers in field studies to assess microbial contamination in refrigerators.

CONDITION OF COLIFORM ORGANISMS INFLUENCING RECOVERY OF SUBCULTURES ON SELECTIVE MEDIA1

1973 ◽  
Vol 36 (8) ◽  
pp. 414-416 ◽  
Author(s):  
R. B. Maxcy
Keyword(s):  
Laboratory Strain ◽  
Selective Medium ◽  
Nutrient Broth ◽  
Heat Radiation ◽  
Coliform Bacteria ◽  
Plate Count ◽  
Indicator Organisms ◽  
Selective Enrichment ◽  
Plate Count Agar ◽  
Health Significance

The effects of stress of coliform bacteria resulting from exposure to heat, radiation, or sodium chloride on behavior of the progeny were studied. After exposure to stress and subsequent growth on plating media, colonies were picked by random design and grown in nutrient broth for further comparison of their ability to form colonies on plate count and violet red bile agar. After 6 hr in nutrient broth, average counts on violet red bile agar were less than half those obtained with plate count agar. Sensitivity to the selective medium was lost by repeated transfer and growth in nutrient broth or by repeated picking from the selective medium and subculture of colonies. Cultures with moderate sensitivity to violet red bile agar were obtained from raw sewage through picking of colonies from plate count agar. Attempts to obtain a stable sensitive strain through selective enrichment were unsuccessful. A laboratory strain of Escherichia coli, with extreme sensitivity to violet red bile agar, however, was used to determine that tolerance was acquired by stepwise adaptation to a selective medium. Occurrence of sensitive coliform cells in nature indicates their potential importance in tests for indicator organisms of public health significance.

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