An assessment of reference method selective broths and plating media using 19 Listeria spp. highlights the importance of including diverse species in Listeria spp. method evaluations

2021 ◽  
Author(s):  
Catharine R Carlin ◽  
Sherry Roof ◽  
Martin Wiedmann
Keyword(s):  
Bacterial Growth ◽  
Reference Method ◽  
Sensu Stricto ◽  
Detection Methods ◽  
Department Of Agriculture ◽  
Method Performance ◽  
The Media ◽  
The U.S ◽  
Selection Of

Reference methods developed for L. monocytogenes are commonly used for Listeria spp. detection. Improved method performance data are needed, since the genus Listeria has expanded from 6 to 26 species and now includes several Listeria sensu lato species, which can show phenotypes distinct from Listeria sensu stricto . Here, we evaluated growth of 19 Listeria spp., including 12 recently described sensu lato species, using the media specified by (i) the U.S. Food and Drug Administration (FDA) Bacteriological Analytical Manual , (ii) the U.S. Department of Agriculture (USDA) Microbiology Laboratory Guidebook , and (iii) the International Organization for Standardization (ISO). The FDA enrichment procedure allowed all species to grow to detectable levels (≥ 4 log 10 ), yielded the highest mean growth (7.58 log 10 ), and was the only procedure where no sensu lato species yielded significantly higher bacterial growth than a sensu stricto species. With the USDA or ISO enrichment procedures several sensu lato species yielded significantly higher bacterial growth than either L. seeligeri or L. ivanovii , suggesting that these two sensu stricto species could be outgrown by sensu lato species. On selective and differential agars, L. seeligeri, L. ivanovii, and L. grayi yielded atypical colony morphologies and/or showed inhibited growth (which may lead to incorrect classification of a sample as negative), while several newly described sensu lato species grew well and showed typical morphologies. Overall, our study shows that the ability to detect different Listeria spp. can be impacted by the specific broth and selective and differential agars used. Our data will aid with selection of media and detection methods for environmental Listeria monitoring programs and facilitate selection of methods that are most likely to detect the targeted Listeria groups (e.g., Listeria sensu stricto, which appear to be the most appropriate index organisms for the pathogen L. monocytogenes ).

Validation of the ANSR® Listeria monocytogenes Method for Detection of Listeria monocytogenes in Selected Food and Environmental Samples

2016 ◽  
Vol 99 (1) ◽  
pp. 112-123
Author(s):  
Oscar Caballero ◽  
Susan Alles ◽  
Quynh-Nhi Le ◽  
R Lucas Gray ◽  
Edan Hosking ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Storage Temperature ◽  
Reference Method ◽  
Single Step ◽  
Stainless Steel Surface ◽  
Method Performance ◽  
Inspection Service ◽  
Nicking Enzyme ◽  
Performance Results ◽  
The U.S

Abstract Work was conducted to validate performance of the ANSR® for Listeria monocytogenes method in selected food and environmental matrixes. This DNA-based assay involves amplification of nucleic acid via an isothermal reaction based on nicking enzyme amplification technology. Following single-step sample enrichment for 16–24 h for most matrixes, the assay is completed in 40 min using only simple instrumentation. When 50 distinct strains of L. monocytogenes were tested for inclusivity, 48 produced positive results, the exceptions being two strains confirmed by PCR to lack the assay target gene. Forty-seven nontarget strains (30 species), including multiple non-monocytogenes Listeria species as well as non-Listeria, Gram-positive bacteria, were tested, and all generated negative ANSR assay results. Performance of the ANSR method was compared with that of the U.S. Department of Agriculture, Food Safety and Inspection Service Microbiology Laboratory Guidebook reference culture procedure for detection of L. monocytogenes in hot dogs, pasteurized liquid egg, and sponge samples taken from an inoculated stainless steel surface. In addition, ANSR performance was measured against the U.S. Food and Drug Administration Bacteriological Analytical Manual reference method for detection of L. monocytogenes in Mexican-style cheese, cantaloupe, sprout irrigation water, and guacamole. With the single exception of pasteurized liquid egg at 16 h, ANSR method performance as quantified by the number of positives obtained was not statistically different from that of the reference methods. Robustness trials demonstrated that deliberate introduction of small deviations to the normal assay parameters did not affect ANSR method performance. Results of accelerated stability testing conducted using two manufactured lots of reagents predicts stability at the specified storage temperature of 4°C of more than 1 year.

Consumer Home Refrigeration Practices: Results of a Web-Based Survey

2007 ◽  
Vol 70 (7) ◽  
pp. 1640-1649 ◽  
Author(s):  
KATHERINE M. KOSA ◽  
SHERYL C. CATES ◽  
SHAWN KARNS ◽  
SANDRIA L. GODWIN ◽  
DELORES CHAMBERS
Keyword(s):  
Older Adults ◽  
Food Safety ◽  
Pregnant Women ◽  
Bacterial Growth ◽  
Quality And Safety ◽  
Educational Materials ◽  
Department Of Agriculture ◽  
Web Based ◽  
Nationally Representative ◽  
The U.S

To reduce bacterial growth and to ensure the quality and safety of food products, the U.S. Department of Agriculture and the U.S. Food and Drug Administration advise consumers to clean their refrigerators regularly, use a refrigerator thermometer, and keep refrigerator temperatures at 40°F (4.4°C) or below. We conducted a nationally representative Web-enabled survey (n = 2,060) to collect data on refrigerator thermometer ownership, home refrigerator temperatures, and the frequency of home refrigerator cleaning. We stratified the sample to provide results for pregnant women, older adults (60 years or older), and the remaining population. About half of all respondents had cleaned their refrigerators at least 1 month before the survey. Only 11% of all respondents had a thermometer in their refrigerator before the survey. Older adults (77.5%) were more likely than the remaining population (70.4%) to have their refrigerators at the recommended temperature (P < 0.01). Older adults who were not married and who lived alone were less likely to have refrigerator thermometers and to have their refrigerators at a recommended temperature (P < 0.05). For all respondents, those who had previously owned a refrigerator thermometer were more likely to have their refrigerators at the recommended temperature than were respondents who did not previously own a thermometer (P < 0.01). Food safety educators can use the survey findings and results of previous research to target educational materials and help consumers, especially those at risk for listeriosis, to safely store refrigerated foods at home.

Detection of Listeria spp. Using ACTERO Listeria Enrichment Media

2014 ◽  
Vol 97 (4) ◽  
pp. 1127-1136
Author(s):  
David Claveau ◽  
Sergiy Olishevskyy ◽  
Michael Giuffre ◽  
Gabriela Martinez
Keyword(s):  
Stainless Steel ◽  
Environmental Samples ◽  
Incubation Temperature ◽  
Reference Method ◽  
Selective Medium ◽  
Single Step ◽  
Department Of Agriculture ◽  
Steel Surfaces ◽  
Inspection Service ◽  
The U.S

Abstract ACTERO™ Listeria Enrichment Media (ACTERO Listeria) is a selective medium developed for a single-step recovery and enrichment of Listeria spp. from environmental samples. Robustness testing of the ACTERO Listeria medium demonstrated good performance when minor changes were introduced to the incubation temperature and time. All 54 Listeria strains tested, representing the most frequently isolated Listeria species from food (L. monocytogenes, L. ivanovii, L. seeligeri, L. welshimeri, and L. grayi), were successfully enriched in ACTERO Listeria. None of the 30 nontarget strains tested in the exclusivity study was recovered after incubation in ACTERO Listeria. Recovery of Listeria was consistent across three independently produced lots of the ACTERO Listeria, and the prepared medium was stable for 45 days when stored at 4°C in the dark. Matrix studies performed with environmental sponge samples from plastic and stainless steel surfaces demonstrated similar recovery of Listeria spp. in a single-step enrichment using ACTERO Listeria from plastic, and significantly better recovery from stainless steel surfaces when compared to the U.S. Department of Agriculture-Food Safety and Inspection Service reference method. The results of this study prove that ACTERO Listeria Enrichment Media can be effectively used in replacement of the two-step enrichment suggested by the reference method without affecting the recovery of Listeria spp. from environmental samples.

scholarly journals Modification of the BAX®Salmonella Test Kit to Include a Hot Start Functionality (Modification of AOAC Official MethodSM 2003.09)

2011 ◽  
Vol 94 (5) ◽  
pp. 1490-1505
Author(s):  
F Morgan Wallace ◽  
Deana DiCosimo ◽  
Andrew Farnum ◽  
George Tice ◽  
Bridget Andaloro ◽  
...  
Keyword(s):  
Reference Method ◽  
Department Of Agriculture ◽  
Reference Methods ◽  
Hot Start ◽  
System Method ◽  
Test Kit ◽  
Aoac Official ◽  
Inspection Service ◽  
Identical Performance ◽  
The U.S

Abstract In 2010, the BAX® System PCR assay for Salmonella was modified to include a hot start functionality designed to keep the reaction enzyme inactive until PCR begins. To validate the assay's Official Methods of Analysis status to include this procedure modification, an evaluation was conducted on four food types that were simultaneously analyzed with the BAX System and either the U.S. Food and Drug Administration's Bacteriological Analytical Manual or the U.S. Department of Agriculture-Food Safety and Inspection Service Microbiology Laboratory Guidebook reference method for detecting Salmonella. Identical performance between the BAX System method and the reference methods was observed. Additionally, lysates were analyzed using both the BAX System Classic and BAX System Q7 instruments with identical results using both platforms for all samples tested. Of the 100 samples analyzed, 34 samples were positive for both the BAX System and reference methods, and 66 samples were negative by both the BAX System and reference methods, demonstrating 100% correlation. No instrument platform variation was observed. Additional inclusivity and exclusivity testing using the modified test kit demonstrated the test kit to be 100% accurate in evaluation of test panels of 352 Salmonella strains and 46 non-Salmonella strains.

SAS™ Molecular Tests Salmonella Detection Kit

2014 ◽  
Vol 97 (3) ◽  
pp. 808-819 ◽  
Author(s):  
Chandra Bapanpally ◽  
Laura Montier ◽  
Shah Khan ◽  
Akif Kasra ◽  
Sharon L Brunelle
Keyword(s):  
Hold Time ◽  
Ground Beef ◽  
Department Of Agriculture ◽  
Test Portion ◽  
Method Performance ◽  
Molecular Tests ◽  
Amplification Method ◽  
Chicken Carcass ◽  
Inspection Service ◽  
The U.S

Abstract The SAS™ Molecular tests Salmonella Detection method, a Loop-mediated Isothermal Amplification method, performed as well as or better than the U.S. Department of Agriculture-Food Safety Inspection Service Microbiology Laboratory Guidebook and the U.S. Food and Drug Administration Bacteriological Analytical Manual reference methods for ground beef, beef trim, ground turkey, chicken carcass rinses, bagged mixed lettuce, and fresh spinach. The ground beef (30% fat, 25 g test portion), poultry matrixes and leafy greens were validated in a 6–7 h enrichment, and ground beef (30% fat, 375 g composite test portion) and beef trim (375 g composite test portion) were validated in a 16–20 h enrichment. The method performance for meat and leafy green matrixes was shown to be acceptable under conditions of co-enrichment with Escherichia coli O157. Thus, after a short 6–7 h co-enrichment step, ground beef, beef trim, lettuce, and spinach can be tested for both Salmonella and E. coli O157. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 100 Salmonella serovars and 30 non- Salmonella species examined. The method was shown to be robust when enrichment time, DNA extract hold time, and DNA volume were varied.

Validation of the ANSR®E. coli O157:H7 Method for Detection of E. coli O157:H7

2016 ◽  
Vol 99 (3) ◽  
pp. 705-716 ◽  
Author(s):  
Ryan Viator ◽  
Susan Alles ◽  
Quynh-Nhi Le ◽  
Edan Hosking ◽  
Evan Meister ◽  
...  
Keyword(s):  
Target Genes ◽  
Ground Beef ◽  
Reference Method ◽  
Single Step ◽  
Fluorescence Detector ◽  
Method Performance ◽  
E Coli ◽  
Reference Methods ◽  
Inspection Service ◽  
The U.S

Abstract A performance validation of the ANSR® for E. coli O157:H7 method was conducted in selected food matrixes. This assay uses selective nicking enzyme amplification technology to amplify target genes. Samples are enriched for 12–24 h and then lysed. The assay is completed within 40 min using real-time detection in a combination incubator/fluorescence detector and software. When 44 distinct strains of Escherichia coli O157:H7 and 6 strains of E. coli O157:NM were tested for inclusivity, all 50 strains produced positive results. In exclusivity testing, 57 strains representing 33 species of closely related Gram-negative bacteria belonging to the Enterobacteriaceae family, including 11 non-H7 O157 strains and shiga toxin-producing E. coli other than O157:H7, were evaluated. All 57 nontarget strains generated negative ANSR assay results. Using 80% lean ground beef and beef trim (approximately 20% fat), ANSR method performance was compared to the U.S. Department of Agriculture, Food Safety and Inspection Service Microbiology Laboratory Guidebook reference culture procedure. ANSR performance with baby spinach and sprout irrigation water was measured against the U.S. Food and Drug Administration Bacteriological Analytical Manual reference method. ANSR method performance was not statistically different to that of the reference methods using two different enrichment options. For ground beef and beef trim, the standard enrichment in modified Tryptone Soya Broth can be analyzed using the ANSR assay with a 1:10 dilution of the enrichment in phosphate-buffered saline and produces equivalent results to the reference method. Additionally, in most matrixes tested (exception is spinach which required 24 h enrichment) the assay offers great efficiency and flexibility over the reference method with a 12–24 h single-step enrichment. Equivalent results were observed at both time points (12 and 24 h) to reference methods. Small changes to the assay parameters minimally affected ANSR method performance. Finally, accelerated stability results from three independently manufactured lots support a shelf-life of 6 months when stored at 4°C.

scholarly journals THE MEDIA INFLUENCE OF TELEVISION FORMATS ON THE VIEWER’S MIND

2021 ◽  
pp. 111-115
Author(s):  
Halyna Kot
Keyword(s):  
Visual Image ◽  
Modern Society ◽  
Modern Culture ◽  
The Media ◽  
Actual Material ◽  
Television Formats ◽  
Semantic Properties ◽  
Conscious Control ◽  
Selection Of

The purpose of the article is to examine and assess the role played by television in modern society in defining the classification of entertaining television formats and the television formats influence on the recipients’ minds. The methodology of the research is based on the selection of the actual material on the suggestive properties study of television is based on the domestic and foreign scholars’ concepts, as well as on the philosophers views, sociologists, semiotics, cultural scientists, art critics, who consider television as a phenomenon of modern culture. The scientific novelty of the work lies in that the semantic properties' perception of reality on TV has got a tendency to withdraw from person’s conscious control and society, pushing the subconscious of the viewer to mythological stereotyping. Conclusions. In practice, everyone is influenced by various media. Creating the whole picture of reality with all its contradictions can bring us to a comprehensive understanding of the world in all its diversity, which will help, in our opinion, overcome the crisis on a television screen, where today a vivid visual image often covers the lack of spirituality and the screen’s aggressiveness.

Use of photodynamic therapy for photodamage skin (review of literature)

2019 ◽  
Vol 1 (7) ◽  
pp. 19-23
Author(s):  
S. I. Surkichin ◽  
N. V. Gryazeva ◽  
L. S. Kholupova ◽  
N. V. Bochkova
Keyword(s):  
Photodynamic Therapy ◽  
Comparative Evaluation ◽  
Clinical Manifestations ◽  
Light Sources ◽  
Review Of Literature ◽  
Photosensitizing Agents ◽  
Selection Of

The article provides an overview of the use of photodynamic therapy for photodamage of the skin. The causes, pathogenesis and clinical manifestations of skin photodamage are considered. The definition, principle of action of photodynamic therapy, including the sources of light used, the classification of photosensitizers and their main characteristics are given. Analyzed studies that show the effectiveness and comparative evaluation in the selection of various light sources and photosensitizing agents for photodynamic therapy in patients with clinical manifestations of photodamage.

The Study of Bacillus Subtils Antimicrobial Activity on Some of the Pathological Isolates

2019 ◽  
Vol 9 (02) ◽  
Author(s):  
Hussein A Kadhum ◽  
Thualfakar H Hasan2
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Bacterial Growth ◽  
Broad Spectrum ◽  
Inhibitory Activity ◽  
Bacterial Pathogens ◽  
Inhibitory Ability ◽  
Selection Of

The study involved the selection of two isolates from Bacillus subtilis to investigate their inhibitory activity against some bacterial pathogens. B sub-bacteria were found to have a broad spectrum against test bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa. They were about 23-30 mm and less against Klebsiella sp. The sensitivity of some antibodies was tested on the test samples. The results showed that the inhibitory ability of bacterial growth in the test samples using B. subtilis extract was more effective than the antibiotics used.

Philosophcal review of h. white̕s tropological theory in the context of the new philosophy of history

2020 ◽  
Vol 3 (152) ◽  
pp. 92-99
Author(s):  
S. M. Geiko ◽  
◽  
O. D. Lauta
Keyword(s):  
Modern Science ◽  
Historical Knowledge ◽  
Text Organization ◽  
The Social ◽  
History Of ◽  
Actual Material ◽  
The Common ◽  
Historical Nature ◽  
Selection Of

The article provides a philosophical analysis of the tropological theory of the history of H. White. The researcher claims that history is a specific kind of literature, and the historical works is the connection of a certain set of research and narrative operations. The first type of operation answers the question of why the event happened this way and not the other. The second operation is the social description, the narrative of events, the intellectual act of organizing the actual material. According to H. White, this is where the set of ideas and preferences of the researcher begin to work, mainly of a literary and historical nature. Explanations are the main mechanism that becomes the common thread of the narrative. The are implemented through using plot (romantic, satire, comic and tragic) and trope systems – the main stylistic forms of text organization (metaphor, metonymy, synecdoche, irony). The latter decisively influenced for result of the work historians. Historiographical style follows the tropological model, the selection of which is determined by the historian’s individual language practice. When the choice is made, the imagination is ready to create a narrative. Therefore, the historical understanding, according to H. White, can only be tropological. H. White proposes a new methodology for historical research. During the discourse, adequate speech is created to analyze historical phenomena, which the philosopher defines as prefigurative tropological movement. This is how history is revealed through the art of anthropology. Thus, H. White’s tropical history theory offers modern science f meaningful and metatheoretically significant. The structure of concepts on which the classification of historiographical styles can be based and the predictive function of philosophy regarding historical knowledge can be refined.

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