scholarly journals Impact of Processing Method on Recovery of Bacteria from Wipes Used in Biological Surface Sampling

2012 ◽  
Vol 78 (16) ◽  
pp. 5872-5881 ◽  
Author(s):  
Autumn S. Downey ◽  
Sandra M. Da Silva ◽  
Nathan D. Olson ◽  
James J. Filliben ◽  
Jayne B. Morrow
Keyword(s):  
Tween 80 ◽  
Surface Sampling ◽  
Risk Characterization ◽  
Processing Methods ◽  
Content Type ◽  
Biological Surface ◽  
Sources Of Variation ◽  
Physical Dissociation ◽  
Performance Results ◽  
Phosphate Buffered Saline

ABSTRACTEnvironmental sampling for microbiological contaminants is a key component of hygiene monitoring and risk characterization practices utilized across diverse fields of application. However, confidence in surface sampling results, both in the field and in controlled laboratory studies, has been undermined by large variation in sampling performance results. Sources of variation include controlled parameters, such as sampling materials and processing methods, which often differ among studies, as well as random and systematic errors; however, the relative contributions of these factors remain unclear. The objective of this study was to determine the relative impacts of sample processing methods, including extraction solution and physical dissociation method (vortexing and sonication), on recovery of Gram-positive (Bacillus cereus) and Gram-negative (Burkholderia thailandensisandEscherichia coli) bacteria from directly inoculated wipes. This work showed that target organism had the largest impact on extraction efficiency and recovery precision, as measured by traditional colony counts. The physical dissociation method (PDM) had negligible impact, while the effect of the extraction solution was organism dependent. Overall, however, extraction of organisms from wipes using phosphate-buffered saline with 0.04% Tween 80 (PBST) resulted in the highest mean recovery across all three organisms. The results from this study contribute to a better understanding of the factors that influence sampling performance, which is critical to the development of efficient and reliable sampling methodologies relevant to public health and biodefense.

scholarly journals Parameters Affecting Spore Recovery from Wipes Used in Biological Surface Sampling

2011 ◽  
Vol 77 (7) ◽  
pp. 2374-2380 ◽  
Author(s):  
Sandra M. Da Silva ◽  
James J. Filliben ◽  
Jayne B. Morrow
Keyword(s):  
Interfacial Energy ◽  
Extraction Efficiency ◽  
Tween 80 ◽  
Deionized Water ◽  
Surface Sampling ◽  
Surface Thermodynamics ◽  
Biological Surface ◽  
Significant Difference ◽  
Centrifuge Tube ◽  
Physical Dissociation

ABSTRACTThe need for the precise and reliable collection of potential biothreat contaminants has motivated research in developing a better understanding of the variability in biological surface sampling methods. In this context, the objective of this work was to determine parameters affecting the efficiency of extractingBacillus anthracisSterne spores from commonly used wipe sampling materials and to describe performance using the interfacial energy concept. In addition, surface thermodynamics was applied to understand and predict surface sampling performance. Wipe materials were directly inoculated with known concentrations ofB. anthracisspores and placed into extraction solutions, followed by sonication or vortexing. Experimental factors investigated included wipe material (polyester, cotton, and polyester-rayon), extraction solution (sterile deionized water [H2O], deionized water with 0.04% Tween 80 [H2O-T], phosphate-buffered saline [PBS], and PBS with 0.04% Tween 80 [PBST]), and physical dissociation method (vortexing or sonication). The most efficient extraction from wipes was observed for solutions containing the nonionic surfactant Tween 80. The increase in extraction efficiency due to surfactant addition was attributed to an attractive interfacial energy between Tween 80 and the centrifuge tube wall, which prevented spore adhesion. Extraction solution significantly impacted the extraction efficiency, as determined by statistical analysis (P< 0.05). Moreover, the extraction solution was the most important factor in extraction performance, followed by the wipe material. Polyester-rayon was the most efficient wipe material for releasing spores into solution by rank; however, no statistically significant difference between polyester-rayon and cotton was observed (P> 0.05). Vortexing provided higher spore recovery in H2O and H2O-T than sonication, when all three wipe materials and the reference control were considered (P< 0.05).

scholarly journals Comparison of Borate Bioactive Glass and Calcium Sulfate as Implants for the Local Delivery of Teicoplanin in the Treatment of Methicillin-Resistant Staphylococcus aureus-Induced Osteomyelitis in a Rabbit Model

2015 ◽  
Vol 59 (12) ◽  
pp. 7571-7580 ◽  
Author(s):  
Wei-Tao Jia ◽  
Qiang Fu ◽  
Wen-Hai Huang ◽  
Chang-Qing Zhang ◽  
Mohamed N. Rahaman
Keyword(s):  
Staphylococcus Aureus ◽  
Bioactive Glass ◽  
Calcium Sulfate ◽  
Rabbit Model ◽  
Local Delivery ◽  
Methicillin Resistant ◽  
Content Type ◽  
Borate Bioactive Glass ◽  
Phosphate Buffered Saline

ABSTRACTThere is growing interest in biomaterials that can cure bone infection and also regenerate bone. In this study, two groups of implants composed of 10% (wt/wt) teicoplanin (TEC)-loaded borate bioactive glass (designated TBG) or calcium sulfate (TCS) were created and evaluated for their ability to release TECin vitroand to cure methicillin-resistantStaphylococcus aureus(MRSA)-induced osteomyelitis in a rabbit model. When immersed in phosphate-buffered saline (PBS), both groups of implants provided a sustained release of TEC at a therapeutic level for up to 3 to 4 weeks while they were gradually degraded and converted to hydroxyapatite. The TBG implants showed a longer duration of TEC release and better retention of strength as a function of immersion time in PBS. Infected rabbit tibiae were treated by debridement, followed by implantation of TBG or TCS pellets or intravenous injection with TEC, or were left untreated. Evaluation at 6 weeks postimplantation showed that the animals implanted with TBG or TCS pellets had significantly lower radiological and histological scores, lower rates of MRSA-positive cultures, and lower bacterial loads than those preoperatively and those of animals treated intravenously. The level of bone regeneration was also higher in the defects treated with the TBG pellets. The results showed that local TEC delivery was more effective than intravenous administration for the treatment of MRSA-induced osteomyelitis. Borate glass has the advantages of better mechanical strength, more desirable kinetics of release of TEC, and a higher osteogenic capacity and thus could be an effective alternative to calcium sulfate for local delivery of TEC.

Accessing offshoring advantages: what and how to offshore

2015 ◽  
Vol 8 (2/3) ◽  
pp. 262-283 ◽  
Author(s):  
Alona Mykhaylenko ◽  
Ágnes Motika ◽  
Brian Vejrum Waehrens ◽  
Dmitrij Slepniov
Keyword(s):  
Performance Outcomes ◽  
Offshore Outsourcing ◽  
Strategic Decisions ◽  
Content Type ◽  
Different Types ◽  
Captive Offshoring ◽  
Performance Results ◽  
Governance Modes ◽  
Different Levels ◽  
Do So

Purpose – The purpose of this paper is to advance the understanding of factors that affect offshoring performance results. To do so, this paper focuses on the access to location-specific advantages, rather than solely on the properties of the offshoring company, its strategy or environment. Assuming that different levels of synergy may exist between particular offshoring strategic decisions (choosing offshore outsourcing or captive offshoring and the type of function) and different offshoring advantages, this work advocates that the actual fact of realization of certain offshoring advantages (getting or not getting access to them) is a more reliable predictor of offshoring success. Design/methodology/approach – A set of hypotheses derived from the extant literature is tested on the data from a quantitative survey of 1,143 Scandinavian firms. Findings – The paper demonstrates that different governance modes and types of offshored function indeed provide different levels of access to different types of location-specific offshoring advantages. This difference may help to explain the ambiguity of offshoring initiatives performance results. Research limitations/implications – Limitations of the work include using only the offshoring strategy elements and only their limited variety as factors potentially influencing access to offshoring advantages. Also, the findings are limited to Scandinavian companies. Originality/value – The paper introduces a new concept of access, which can help to more reliably predict performance outcomes of offshoring initiatives. Recommendations are also provided to practitioners dealing with offshoring initiatives.

Loss reserve variability and loss reserve errors

2014 ◽  
Vol 15 (3) ◽  
pp. 248-263 ◽  
Author(s):  
Enoch Nii Boi Quaye ◽  
Charles Andoh ◽  
Anthony Q.Q. Aboagye
Keyword(s):  
Insurance Companies ◽  
Content Type ◽  
Main Research ◽  
Loss Reserve ◽  
Smooth Flow ◽  
Regulatory Standards ◽  
Sources Of Variation ◽  
Regulatory Bodies ◽  
Property And Liability Insurance ◽  
Industry Trends

Purpose – The purpose of this study is to assess the level and variability of Ghanaian property and liability insurer’s reserve estimates to examine its sources and ascertain if reserve errors are random or not (i.e. manipulated or not). Design/methodology/approach – It uses information on insurer claim reserve provisions, claims outstanding, claims incurred and claims paid for the period of 2000-2010. Categorizing the sources of variation as endogenous and exogenous, the authors use the panel correlated standard error regression model to determine sources and magnitude of industry reserve error. Findings – The study finds that size, age, lag of loss reserve error, inflation rate and real gross domestic product are significant in determining the degree of reserve error variation. Type of ownership (domestic or foreign) is, however, not a significant source of variation. Further, the authors found that industry reserve errors are random (not manipulated) across firms, suggesting that sampled insurers act independently on reserve error decision making and are not influenced by industry trends and competition. Research limitations/implications – The main research study limitation is the difficulty involved in obtaining annual statements from insurance companies in Ghana. Reluctance of companies to make statements available impeded on the smooth flow of the study during data collection. Practical implications – Policy-wise, this suggest that regulatory bodies can uniquely set reserve error levels for existing firms with little influence on competition. Further, the Ghanaian insurance regulator does not to focus on the type of ownership (foreign or local) when setting regulatory standards. However, size of the company and age (length of operation) should be considered. Originality/value – This paper is the first empirical study to examine the loss reserve error and loss reserve variability of Ghanaian property and liability insurance companies.

scholarly journals Efficacy of a Sonicating Swab for Removal and Capture of Listeria monocytogenes in Biofilms on Stainless Steel

2017 ◽  
Vol 83 (11) ◽  
Author(s):  
Tobyn A. Branck ◽  
Matthew J. Hurley ◽  
Gianna N. Prata ◽  
Christina A. Crivello ◽  
Patrick J. Marek
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Laser Scanning ◽  
Laser Scanning Confocal Microscopy ◽  
Ease Of Use ◽  
Surface Sampling ◽  
Cell Recovery ◽  
Electron Microscopic ◽  
Content Type ◽  
Scanning Electron

ABSTRACT Listeria monocytogenes is of great concern in food processing facilities because it persists in biofilms, facilitating biotransfer. Stainless steel is commonly used for food contact surfaces and transport containers. L. monocytogenes biofilms on stainless steel served as a model system for surface sampling, to test the performance of a sonicating swab in comparison with a standard cotton swab. Swab performance and consistency were determined using total viable counts. Stainless steel coupons sampled with both types of swabs were examined using scanning electron microscopy, to visualize biofilms and surface structures (i.e., polishing grooves and scratches). Laser scanning confocal microscopy was used to image and to quantitate the biofilms remaining after sampling with each swab type. The total viable counts were significantly higher (P ≤ 0.05) with the sonicating swab than with the standard swab in each trial. The sonicating swab was more consistent in cell recovery than was the standard swab, with coefficients of variation ranging from 8.9% to 12.3% and from 7.1% to 37.6%, respectively. Scanning electron microscopic imaging showed that biofilms remained in the polished grooves of the coupons sampled with the standard swab but were noticeably absent with the sonicating swab. Percent area measurements of biofilms remaining on the stainless steel coupons showed significantly (P ≤ 0.05) less biofilm remaining when the sonicating swab was used (median, 1.1%), compared with the standard swab (median, 70.4%). The sonicating swab provided greater recovery of cells, with more consistency, than did the standard swab, and it is employs sonication, suction, and scrubbing. IMPORTANCE Inadequate surface sampling can result in foodborne illness outbreaks from biotransfer, since verification of sanitization protocols relies on surface sampling and recovery of microorganisms for detection and enumeration. Swabbing is a standard method for microbiological sampling of surfaces. Although swabbing offers portability and ease of use, there are limitations, such as high user variability and low recovery rates, which can be attributed to many different causes. This study demonstrates some benefits that a sonicating swab has over a standard swab for removal and collection of microbiological samples from a surface, to provide better verification of surface cleanliness and to help decrease the potential for biotransfer of pathogens into foods.

Organizational capability for change and performance in artisanal businesses in Mexico

2020 ◽  
Vol 33 (2) ◽  
pp. 415-431
Author(s):  
Patricia S. Sánchez-Medina
Keyword(s):  
Environmental Performance ◽  
Design Methodology ◽  
Dynamic Capabilities ◽  
Organizational Changes ◽  
Organizational Capability ◽  
Content Type ◽  
Face To Face ◽  
And Performance ◽  
Performance Results ◽  
The Relationship

PurposeBusinesses in Mexico, particularly small and mid-sized companies, are faced with numerous challenges: a lack of competition, difficulty in positioning and maintaining oneself in the market, irrational use of natural resources, and poverty in the environment in which they develop. In spite of these problems, many are able to succeed; however, there is limited knowledge about how these businesses could implement organizational changes that would positively impact their results.Design/methodology/approachUsing dynamic capabilities theory and survey data obtained from pottery businesses in several artisan communities in Mexico through the application of face-to-face interviews, this paper analyzes the relationship between organizational capability for change (OCC) and economic and environmental performance.FindingsThis research proves that OCC positively and significantly impacts economic and environmental performance. Results contribute to the existing literature on OCC in the context of poverty.Originality/valueThis study offers empirical research that illustrates the relationship between OCC and the environmental and economic performance of pottery businesses. Additionally it contributes to a field of knowledge in progress; that is, OCC in contexts of subsistence where poverty is a constant issue. Artisans living in this context can also develop business capabilities that contribute to the permanence of their business in the market.

Argumentation-based schema matching for multiple digital libraries

2015 ◽  
Vol 39 (1) ◽  
pp. 81-103
Author(s):  
Tho Thanh Quan ◽  
Xuan H. Luong ◽  
Thanh C. Nguyen ◽  
Hui Siu Cheung
Keyword(s):  
Information Retrieval ◽  
Digital Libraries ◽  
Design Methodology ◽  
Schema Matching ◽  
Retrieval Performance ◽  
Content Type ◽  
Retrieval Efficiency ◽  
Automatic Mapping ◽  
Computer Based ◽  
Performance Results

Purpose – Most digital libraries (DL) are now available online. They also provide the Z39.50 standard protocol which allows computer-based systems to effectively retrieve information stored in the DLs. The major difficulty lies in inconsistency between database schemas of multiple DLs. The purpose of this paper is to present a system known as Argumentation-based Digital Library Search (ADLSearch), which facilitates information retrieval across multiple DLs. Design/methodology/approach – The proposed approach is based on argumentation theory for schema matching reconciliation from multiple schema matching algorithms. In addition, a distributed architecture is proposed for the ADLSearch system for information retrieval from multiple DLs. Findings – Initial performance results are promising. First, schema matching can improve the retrieval performance on DLs, as compared to the baseline technique. Subsequently, argumentation-based retrieval can yield better matching accuracy and retrieval efficiency than individual schema matching algorithms. Research limitations/implications – The work discussed in this paper has been implemented as a prototype supporting scholarly retrieval from about 800 DLs over the world. However, due to complexity of argumentation algorithm, the process of adding new DLs to the system cannot be performed in a real-time manner. Originality/value – In this paper, an argumentation-based approach is proposed for reconciling the conflicts from multiple schema matching algorithms in the context of information retrieval from multiple DL. Moreover, the proposed approach can also be applied for similar applications which require automatic mapping from multiple database schemas.

scholarly journals Fast and Sensitive Detection of Bacillus anthracis Spores by Immunoassay

2012 ◽  
Vol 78 (18) ◽  
pp. 6491-6498 ◽  
Author(s):  
Nathalie Morel ◽  
Hervé Volland ◽  
Julie Dano ◽  
Patricia Lamourette ◽  
Patricia Sylvestre ◽  
...  
Keyword(s):  
Bacillus Anthracis ◽  
Electrical Current ◽  
Biological Weapons ◽  
Meso Scale Discovery ◽  
Simple Method ◽  
Content Type ◽  
Bacillus Anthracis Spores ◽  
Luminescent Signal ◽  
Sample Purification ◽  
Phosphate Buffered Saline

ABSTRACTBacillus anthracisis one of the most dangerous potential biological weapons, and it is essential to develop a rapid and simple method to detectB. anthracisspores in environmental samples. The immunoassay is a rapid and easy-to-use method for the detection ofB. anthracisby means of antibodies directed against surface spore antigens. With this objective in view, we have produced a panel of monoclonal antibodies againstB. anthracisand developed colorimetric and electrochemiluminescence (ECL) immunoassays. Using Meso Scale Discovery ECL technology, which is based on electrochemiluminescence (ECL) detection utilizing a sulfo-Tag label that emits light upon electrochemical stimulation (using a dedicated ECL plate reader, an electrical current is placed across the microplate with electrodes integrated into the bottom of the plate, resulting in a series of electrically induced reactions leading to a luminescent signal), a detection limit ranging between 0.3 × 103and 103CFU/ml (i.e., 30 to 100 spores per test), depending on theB. anthracisstrain assayed, was achieved. In complex matrices (5 mg/ml of soil or simulated powder), the detection level (without any sample purification or concentration) was never altered more than 3-fold compared with the results obtained in phosphate-buffered saline.

Pearl millet processing: a review

2018 ◽  
Vol 48 (1) ◽  
pp. 30-44 ◽  
Author(s):  
Savita Rani ◽  
Rakhi Singh ◽  
Rachna Sehrawat ◽  
Barjinder Pal Kaur ◽  
Ashutosh Upadhyay
Keyword(s):  
Pearl Millet ◽  
Pennisetum Glaucum ◽  
Journal Articles ◽  
Processing Methods ◽  
Nutritional Factors ◽  
Content Type ◽  
Review Study ◽  
Nutritional Compounds ◽  
Major Factors ◽  
The Impact

Purpose Pearl millet (Pennisetum glaucum) is a rich source of nutrients as compared to the major cultivated cereal crops. However, major factors which limit its utilization are the presence of anti-nutritional factors (phytate, tannins and polyphenols) which lower availability of minerals and poor keeping quality because of higher lipase activity. Therefore, this paper aims to focus on the impact of different processing methods on the nutrient composition and anti-nutritional components of pearl millet. Design/methodology/approach This is a literature review study from 1983 to 2017, focusing on studies related to pearl millet processing and their effectiveness in the enrichment of nutritional value through reduction of anti-nutritional compounds. Findings From the literature reviewed, pearl millet processing through various methods including milling, malting, fermentation, blanching and acid as well as heat treatments were found to be effective in achieving the higher mineral digestibility, retardation of off flavor, bitterness as well as rancidity problems found during storage of flour. Originality/value Through this review paper, possible processing methods and their impact on the nutrient and anti-nutrient profile of pearl millet are discussed after detailed studied of literature from journal articles and thesis.

scholarly journals Effect of Long-Term Starvation on the Survival, Recovery, and Carbon Utilization Profiles of a Bovine Escherichia coli O157:H7 Isolate from New Zealand

2014 ◽  
Vol 80 (14) ◽  
pp. 4383-4390 ◽  
Author(s):  
Ron N. Xavier ◽  
Hugh W. Morgan ◽  
Ian R. McDonald ◽  
Helen Withers
Keyword(s):  
Escherichia Coli ◽  
New Zealand ◽  
Membrane Integrity ◽  
Nutrient Level ◽  
Carbon Utilization ◽  
Content Type ◽  
E Coli ◽  
Significant Difference ◽  
Carbon Utilization Profiles ◽  
Phosphate Buffered Saline

ABSTRACTThe ability to maintain a dual lifestyle of colonizing the ruminant gut and surviving in nonhost environments once shed is key to the success ofEscherichia coliO157:H7 as a zoonotic pathogen. Both physical and biological conditions encountered by the bacteria are likely to change during the transition between host and nonhost environments. In this study, carbon starvation at suboptimal temperatures in nonhost environments was simulated by starving a New Zealand bovineE. coliO157:H7 isolate in phosphate-buffered saline at 4 and 15°C for 84 days. Recovery of starved cells on media with different nutrient availabilities was monitored under aerobic and anaerobic conditions. We found that the New Zealand bovineE. coliO157:H7 isolate was able to maintain membrane integrity and viability over 84 days and that the level of recovery depended on the nutrient level of the recovery medium as well as the starvation temperature. In addition, a significant difference in carbon utilization was observed between starved and nonstarved cells.

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