scholarly journals A comparison of ten USEPA approved total coliform/E. coli tests

2007 ◽  
Vol 5 (2) ◽  
pp. 267-282 ◽  
Author(s):  
Jeremy Olstadt ◽  
James Jay Schauer ◽  
Jon Standridge ◽  
Sharon Kluender
Keyword(s):  
Environmental Protection Agency ◽  
False Positive ◽  
The United States ◽  
Total Coliform ◽  
Test System ◽  
E Coli ◽  
Test Systems ◽  
High Concentrations ◽  
Different Strains ◽  
Positive Results

Since 2002, the United States Environmental Protection Agency (USEPA) has approved ten enzyme-based total coliform and E. coli detection tests for examination of drinking water. These tests include: Colilert®, Colilert-18®, Colisure®, m-Coli Blue 24®, Readycult® Coliforms 100, Chromocult®, Coliscan®, E*Colite®, Colitag™ and MI Agar. The utility of the enzyme based test systems is based on both the ability of the test to detect the target organisms at low levels and the ability of the test system to suppress the growth of non-target organisms that might result in false positive results. Differences in the ability of some of these methods to detect total coliform and E. coli, as well as suppress Aeromonas spp., a common cause of “false positive” results, have been observed. As a result, this study was undertaken to elucidate the strengths and weaknesses of each method. Water samples were collected from three geographically and chemically diverse groundwaters in Wisconsin. One-hundred milliliter aliquots were individually spiked with both low concentrations (one to ten organisms) and high concentrations (fifty to one-hundred) of each of five different total coliform organisms (Serratia, Citrobacter, Enterobacter, E. coli, & Klebsiella). These spiked samples were used to test the capability of ten enzyme-based test systems to both detect and enumerate the spiked organisms. In addition, 100 ml samples were independently spiked with two different strains of Aeromonas spp. at six different levels, to assess the ability of each enzyme-based test to suppress Aeromonas spp. Analysis of the data indicated that wide variability exists among USEPA approved tests to detect and quantify total coliforms, as well as suppress Aeromonas spp.

scholarly journals Reveal 8-Hour Test System for Detection of Escherichia coli O157:H7 in Raw Ground Beef, Raw Beef Cubes, and Iceberg Lettuce Rinse: Collaborative Study

2001 ◽  
Vol 84 (3) ◽  
pp. 719-736 ◽  
Author(s):  
Charles B Bird ◽  
Rebecca J Hoerner ◽  
Lawrence Restaino ◽  
G Anderson ◽  
W Birbari ◽  
...  
Keyword(s):  
Collaborative Study ◽  
Ground Beef ◽  
Culture Method ◽  
The United States ◽  
Test System ◽  
Private Industry ◽  
E Coli ◽  
Inspection Service ◽  
High Level ◽  
The U.S

Abstract Five different food types were analyzed by the Reveal for E. coli O157:H7 8-Hour Test System (Reveal 8) and either the U.S. Food and Drug Administration's Bacteriological Analytical Manual (BAM) culture method or the U.S. Department of Agriculture Food Safety Inspection Service (FSIS) culture method for the presence of E. coli O157:H7. A total of 27 laboratories representing academia and private industry in the United States and Canada participated. Food types were inoculated with E. coli O157:H7 at 2 different levels: a high level where predominantly positive results were expected, and a low level where fractional recovery was anticipated. During this study, 1110 samples and controls were analyzed by both the Reveal 8 and by BAM or FSIS by each of the collaborators (2220 samples in total). For each set of samples, 740 were artificially inoculated with E. coli O157:H7, and 370 were uninoculated controls. The Reveal 8 detected 528 presumptive positives of which 487 were confirmed positive by the BAM culture method. In comparison, BAM and FSIS detected 489 of the 740 artificially contaminated samples as positive. In an additional in-house study performed only on chilled and frozen raw ground beef, 240 artificially inoculated samples were analyzed by both the Reveal 8 and by FSIS. The Reveal 8 detected and confirmed 104 samples as positive compared to 79 confirmed positive by FSIS.

scholarly journals Residues of Persistent Organic Pollutants (POPs) in Agricultural Soils Adjacent to Historical Sources of Their Storage and Distribution—The Case Study of Azerbaijan

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1815 ◽  
Author(s):  
Aleksandra Ukalska-Jaruga ◽  
Karolina Lewińska ◽  
Elton Mammadov ◽  
Anna Karczewska ◽  
Bożena Smreczak ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Environmental Protection Agency ◽  
Agricultural Soils ◽  
The United States ◽  
Natural Soil ◽  
Polycyclic Aromatic ◽  
High Concentrations ◽  
Total Concentrations

The aim of this study was to identify and examine the levels of organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) in soil collected from the surroundings of historical pesticide storage facilities on former agricultural aerodromes, warehouses, and pesticide distribution sites located in the most important agricultural regions in Azerbaijan. The conducted research included determination of three groups of POPs (occurring together), in the natural soil environment influenced for many years by abiotic and biotic factors that could have caused their transformations or decomposition. In this study, soil samples were collected in 21 georeferenced points located in the administrative area of Bilasuvar, Saatly, Sabirabad, Salyan and Jalilabad districts of Azerbaijan. Soil chemical analysis involved determination of organochlorine compounds (OCP): hexachlorocyclohexanes (HCHs) (three isomers α-HCH, β-HCH and γ-HCH) and dichlorodiphenyltrichloroethanes (DDTs) (six congeners 2,4′DDT; 4,4′DDT; 2,4′DDE; 4,4′DDE; 2,4′DDE; and 4,4′DDE); polycyclic aromatic hydrocarbons (PAHs): 16 compounds from the United States Environmental Protection Agency US EPA list and, PCBs (seven congeners identified with the following IUPAC numbers: 28, 52, 101, 118, 138, 153, and 180). Our research showed that OCPs reached the highest concentration in the studied areas. The total concentrations of OCPs ranged from 0.01 to 21,888 mg∙kg−1 with significantly higher concentrations of Σ6DDTs (0.01 μg kg−1 to 21880 mg kg−1) compared to ΣHCH (0.14 ng kg−1 to 166.72 µg kg−1). The total concentrations of PCBs in the studied soils was varied from 0.02 to 147.30 μg·kg−1 but only PCB138 and PCB180 were detected in all analyzed samples. The concentrations of Σ16 PAHs were also strongly diversified throughout the sampling areas and ranged from 0.15 to 16,026 mg kg−1. The obtained results confirmed that the agricultural soils of Azerbaijan contained much lower (up to by three orders of magnitude) concentrations of PCBs and PAHs than DDT. It is supported by the fact that PCBs and PAHs were not directly used by agriculture sector and their content results from secondary sources, such as combustion and various industrial processes. Moreover, the high concentrations of PAHs in studied soils were associated with their location in direct neighborhood of the airport, as well as with accumulation of contaminants from dispersed sources and long range transport. The high concentrations of pesticides confirm that deposition of parent OCPs have occurred from obsolete pesticide landfills.

scholarly journals Detection of AmpC β-lactamases in Escherichia coli using different screening agars

2019 ◽  
Author(s):  
Evert den Drijver ◽  
Jaco J. Verweij ◽  
Carlo Verhulst ◽  
Joke Soer ◽  
Kees Veldman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Confidence Interval ◽  
Sensitivity And Specificity ◽  
False Positive ◽  
E Coli ◽  
Specificity And Sensitivity ◽  
Positive Results

AbstractThe aim of this study was to determine the performance of both cefotaxime and ceftazidime containing agars on the specificity and sensitivity for chromosomal AmpC-hyperproducing and plasmid AmpC harboring Escherichia coli compared to ESBL-producing E. coli and E. coli without ESBL, pAmpC or cAmpC hyperproduction. Second, we evaluated the influence of adding cefoxitin to these agars for detection of both chromosomal AmpC-hyperproducing and plasmid AmpC harboring E. coli.Four different homemade screening agars with cefotaxime (1mg/L), ceftazidime (1mg/L), cefotaxime (1mg/L) with cefoxitin (8mg/L), and ceftazidime (1mg/L) with cefoxitin (8mg/L) were compared to each other for the identification of AmpC producing E. coli. A total of 40 isolates with plasmid encoded AmpC β-lactamases, 40 isolates with alterations in the promoter/attenuator region of the AmpC gene leading to hyperproduction of the β-lactamase, 40 isolates with ESBL genes and 39 isolates lacking both a AmpC and ESBL genotype were used to test the four agars.The sensitivity and specificity were 100% (95% confidence interval (95% CI) 96.1% to 100%) and 48.1% (95% CI 38.6%-60.2%), respectively, for the cefotaxime agar; 100% (95% CI 96.1% to 100%) and 49.41% (95% CI 39.8%-61.4%), respectively, for the ceftazidime agar; 96.3% (95% CI 89.1% to 99.2%) and 77.2% (95% CI 66.7%-85.2%) respectively, for the cefotaxime with cefoxitin agar; 98.8% (95% CI) 92.6% to 99.6%) and 81.0% (95% CI 70.9%-88.3%) respectively, for the ceftazidime agar with cefoxitin. The main reason for false-positive results were ESBL-harboring strains that grew on various agars; therefore, the specificity of each agar reported here was influenced mainly by the proportion of ESBL isolates tested. In conclusion addition of cefoxitin to cefotaxime and ceftazidime containing agars had little influence on sensitivity, but increased specificity for the detection of AmpC in E. coli.

scholarly journals Evaluation of Physical Chemical and Biological Characteristics of Underground Wells in Badra City, Iraq

2019 ◽  
Vol 16 (3) ◽  
pp. 0560
Author(s):  
Kadhim Hashim Yaseen Al-Araji
Keyword(s):  
Total Coliform ◽  
Plate Count ◽  
The Public ◽  
E Coli ◽  
Quality Of Water ◽  
Advance Method ◽  
Pollution Detection ◽  
Private Wells ◽  
Positive Results

The quality of groundwater should be improved by keeping safe water sources from contaminants in protective way by doing regular measuring and checkup before it supplied for usage. Private Wells do not receive the same services that wells supplying the public do. Well owners are responsible for protecting their drinking water. This work was carried out in Badra city, Iraq from December 2017 to May 2018, six wells water were investigated to determine the general characteristics of wells as well as studying the effect of environmental factors on the quality of water. The average of six wells were eleven parameters that is out of permissible limits were EC, Sal., Alk., TH, TDS, Na, Ca, Cl, SO4, Fe, Zn (4402-5183 /cm, 2.76-3.9 ppt, 302-366mg/L, 3164-4248 mg/L, 604-675 mg/L, 375-524 mg/L, 635-871 mg/L, 631-1107 mg/L, 2430-4570 g/L, 114-392 g/L). Respectively, microbiological investigations involved the total coliform, total plate count, as well as the detection for the presence of E. coli, Salmonella and Cholera.  Results shows that there is a significant relation between the increasing of the TDS and Turbidity, TDS gives an indication for the significant increasing of chemical ions. Wells number 3, 4 and 5 showed gave positive results for E.coli growth which as a source of microbial pollution. Detection for the presence of chemical and microbial contaminate is an important alarm since this water has a direct effect on the human and animal's health. Advance method of rapid detection for the well water quality is highly recommended to avoid any health issue and prevent the outbreak of health risk and ecological contaminants.

Microbial Contamination Occurring on Lamb Carcasses Processed in the United States

2001 ◽  
Vol 64 (4) ◽  
pp. 503-508 ◽  
Author(s):  
E. A. DUFFY ◽  
K. E. BELK ◽  
J. N. SOFOS ◽  
S. B. LeVALLEY ◽  
M. L. KAIN ◽  
...  
Keyword(s):  
United States ◽  
Microbial Contamination ◽  
The United States ◽  
Total Coliform ◽  
Regulatory Requirements ◽  
Salmonella Spp ◽  
E Coli ◽  
Total Incidence ◽  
Tissue Surface ◽  
Plate Counts

Lamb carcasses (n = 5,042) were sampled from six major lamb packing facilities in the United States over 3 days during each of two visits (fall or winter, October through February; spring, March through June) in order to develop a microbiological baseline for the incidence (presence or absence) of Salmonella spp. and for populations of Escherichia coli after 24 h of chilling following slaughter. Samples also were analyzed for aerobic plate counts (APC) and total coliform counts (TCC). Additionally, incidence (presence or absence) of Campylobacter jejuni/coli on lamb carcasses (n = 2,226) was determined during the slaughtering process and in the cooler. All samples were obtained by sponge-sampling the muscle-adipose tissue surface of the flank, breast, and leg of lamb carcasses (100 cm2 per site; 300 cm2 total). Incidence of Salmonella spp. in samples collected from chilled carcasses was 1.5% for both seasons combined, with 1.9% and 1.2% of fall or winter and spring samples being positive, respectively. Mean (log CFU/cm2) APC, TCC, and E. coli counts (ECC) on chilled lamb carcasses across both seasons were 4.42, 1.18, and 0.70, respectively. APC were lower (P < 0.05) in samples collected in the spring versus fall or winter, while TCC were higher in samples collected in the spring. There was no difference (P > 0.05) between ECC from samples collected in the spring versus winter. Only 7 out of 2,226 total samples (0.3%) tested positive for C. jejuni/coli, across all sampling sites. These results should be useful to the lamb industry and regulatory authorities as new regulatory requirements for meat inspection become effective.

scholarly journals Membrane filtration media for the enumeration of coliform organisms and Escherichia coli in water: comparison of Tergitol 7 and lauryl sulphate with Teepol 610

1980 ◽  
Vol 85 (2) ◽  
pp. 181-191 ◽  
Author(s):  
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
False Positive ◽  
Membrane Filtration ◽  
Sodium Lauryl Sulphate ◽  
Standard Medium ◽  
E Coli ◽  
Laboratory Trial ◽  
Positive Results ◽  
Filtration Technique

SUMMARYIn a multi-laboratory trial with the mombrane filtration technique, three surfactants – Teepol 610 (T610), Tergitol 7 (T7) and sodium lauryl sulphate (LS) – were compared in media for the enumeration of coliform organisms and Escherichia coli in water. A total of 170 samples of water (87 raw and 92 marginally chlorinated) were examined for colony counts of coliform organisms, and 185 water samples (94 raw and 91 marginally chlorinated) for E. coli. Slight differences in the confirmed colony counts between the three media were noted, but few of these were observed consistently in every laboratory. In most laboratories, T7 gave slightly higher counts of E. coli than LS with chlorinated waters; a higher incidence of false-positive results for E. coli at 44 °C was also noted with T7. As there were no outstanding differences in the trial, sodium lauryl sulphate, which is chemically defined, cheap and readily available, is therefore recommended for use at a concentration of 0·1% instead of Teepol 610 in the standard medium for the enumeration of coliform organisms and E. coli in water by the membrane filtration technique.

Industrial and Agricultural Chemicals

PEDIATRICS ◽  
1974 ◽  
Vol 53 (5) ◽  
pp. 843-844
Author(s):  
S. Hope Sandifer
Keyword(s):  
South Carolina ◽  
Environmental Protection Agency ◽  
Small Sample Size ◽  
The United States ◽  
Small Sample ◽  
Adult Males ◽  
Community Studies ◽  
Water Supplies ◽  
Intermittent Exposure ◽  
High Concentrations

The alert practitioner should know the types of pollution created by agriculture and industry in his area. In agriculture, two important pollutants are nitrates and pesticides (which include insecticides, herbicides, fungicides, rodenticides, and defoliants). Pediatricians are well aware of methemoglobmnemia due to excessive nitrates in water. Nitrates in water supplies are of increasing concern because of runoff from feed lots and incremental use of fertilizers. Tolerance levels of nitrate in municipal water supplies are established, and pediatricians should insist that these standards be enforced in their community. With regard to pesticides, the Environmental Protection Agency has funded 13 community studies throughout the United States. The purpose is to monitor the health of pesticide workers compared with suitable controls. To date no significant health effects have been demonstrated. Most studies have been made on adult males because of their occupational exposure to pesticides. The groups under surveillance include workers who manufacture pesticides, pest-control operators who spray daily, and farmers who have intermittent exposure to high concentrations of pesticides. We are seeking the effects, if any, in the most heavily exposed persons before trying to determine the effects of smaller doses. This approach suffers the problem of small sample size (several thousand instead of hundreds of thousands of exposed persons). Our studies and those of others have shown that DDT in the sera of blacks is about two to three times that of whites.1-3 We had assumed that this difference was due to environmental exposure, but recent studies in Charleston, South Carolina, have suggested a genetic factor.

Place of serological test-systems for detection of antibodies to SARS-CoV2 in emergency cardiac surgery

2021 ◽  
pp. 18-21
Author(s):  
O. V. Petrova ◽  
D. K. Tverdokhlebova ◽  
D. M. Nikulina ◽  
D. G. Tarasov
Keyword(s):  
Cardiac Surgery ◽  
Human Serum ◽  
False Positive ◽  
Laboratory Testing ◽  
Serological Test ◽  
Confirmatory Test ◽  
Serum Antibodies ◽  
Laboratory Assessment ◽  
Test Systems ◽  
Positive Results

The article reveals the need for a comprehensive laboratory assessment of testing for antibodies to SARS-CoV-2. In progress it is focused on the possible product of laboratory testing studies of false-positive results caused by the presence of human serum antibodies in that cross reacting with SARS-CoV-2 proteins. It is concluded that in order to reduce the proportion of false positive results of the study require the use of confirmatory test.

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