Search results for "Microbiological Technique"
showing 10 items of 24 documents
Third-generation hepatitis C virus tests in asymptomatic anti-HCV-positive blood donors
1994
This study evaluated the performance of third-generation anti-HCV assays in blood donors who were positive by second-generation anti-HCV, and assessed any possible relationship between antibody patterns, HCV replication and liver damage. Fifty-two second-generation enzyme immunoassay-positive asymptomatic Italian blood donors were retested for anti-HCV by third-generation enzyme immunoassay and recombinant immunoblot assay (Ortho third-generation enzyme immunoassay, third-generation recombinant immunoblot assay), utilising recombinant C33c and NS5 and synthetic peptide C100 and C22 antigens, and for HCV-RNA by "nested" polymerase chain reaction with 5' region primers. Alanine aminotransfera…
Automatic Biological Cell Counting Using a Modified Gradient Hough Transform
2017
AbstractWe present a computational method for pseudo-circular object detection and quantitative characterization in digital images, using the gradient accumulation matrix as a basic tool. This Gradient Accumulation Transform (GAT) was first introduced in 1992 by Kierkegaard and recently used by Kaytanli & Valentine. In the present article, we modify the approach by using the phase coding studied by Cicconet, and by adding a “local contributor list” (LCL) as well as a “used contributor matrix” (UCM), which allow for accurate peak detection and exploitation. These changes help make the GAT algorithm a robust and precise method to automatically detect pseudo-circular objects in a microscop…
Post-mortem microbiology in sudden death: sampling protocols proposed in different clinical settings
2019
Abstract Background Autopsies, including minimally invasive autopsies, are a powerful tool for determination of the cause of death. When a patient dies from an infection, microbiology is crucial to identify the causative organism. Post-mortem microbiology (PMM) aims to detect unexpected infections causing sudden deaths; confirm clinically suspected but unproven infection; evaluate the efficacy of antimicrobial therapy; identify emergent pathogens; and recognize medical errors. Additionally, the analysis of the thanatomicrobiome may help to estimate the post-mortem interval. Aims The aim was to provide advice in the collection of PMM samples and to propose sampling guidelines for microbiolog…
Identification of cryptic Candida species by MALDI-TOF mass spectrometry, not all MALDI-TOF systems are the same: focus on the C. parapsilosis specie…
2016
Data about the performance of MALDI-TOF mass spectrometry against cryptic Candida species are limited. According to our findings within the C. parapsilosis species complex, microbiologists should be aware that the choice of the instrument is critical for accurate species identification due to the risk of misidentification in the clinical setting.
In vitro fungicidal activities of echinocandins against Candida metapsilosis, C. orthopsilosis, and C. parapsilosis evaluated by time-kill studies.
2010
ABSTRACT Anidulafungin, micafungin, and caspofungin in vitro activities against Candida metapsilosis , C. orthopsilosis , and C. parapsilosis were evaluated by MICs and time-kill methods. All echinocandins showed lower MICs (mean MICs, 0.05 to 0.71 mg/liter) and the highest killing rates (−0.06 to −0.05 CFU/ml/h) for C. metapsilosis and C. orthopsilosis rather than for C. parapsilosis (mean MICs, 0.59 to 1.68 mg/liter). Micafungin and anidulafungin killing rates were greater than those determined for caspofungin. None of the echinocandins had fungicidal activity against C. parapsilosis .
Determination of mycotoxins produced by Fusarium isolates from banana fruits by capillary gas chromatography and high-performance liquid chromatograp…
1997
A method of analysis for trichothecenes (nivalenol, deoxynivalenol, 3- and 15-acetyldeoxynivalenol, diacetoxyscirpenol, neosolaniol, T-2 tetraol, T-2 and HT-2 toxins), zearalenone and zearalenols, and another method for determination of fumonisin B1 are described and applied to cultures of Fusarium isolated from bananas. Both methods were adapted from different techniques of extraction, clean-up and determination of these mycotoxins. The first method involves extraction with methanol-1% aqueous sodium chloride, clean-up of extracts by partition with hexane and dichloromethane, additional solid reversed-phase clean-up and analysis of two eluates by both high-performance liquid chromatography…
Validation of a predictive model for the growth of Botrytis cinerea and Penicillium expansum on grape berries.
2010
The objective of this study was to develop and to validate a model for predicting the combined effect of temperature and a(w) on the radial growth rate, mu, of Botrytis cinerea and Penicillium expansum on grape berries. The proposed strategy was based on the gamma-concept developed previously [Zwietering, M.H., Wijtzes, T., de Wit, J.C., van't Riet, K. 1992. A decision support system for prediction of the microbial spoilage in foods. Journal of Food Protection. 12, 973-979]: mu=mu(opt).gamma(T).gamma(a(w)), where the gamma functions were cardinal models with inflection (CMI), mu(opt) the radial growth rate on grape berries. Firstly, the cardinal temperatures and a(w)'s were estimated indepe…
Microbial communities of the Mediterranean rocky shore: ecology and biotechnological potential of the sea‐land transition
2019
Microbial communities from harsh environments hold great promise as sources of biotechnologically relevant strains and compounds. In the present work, we have characterized the microorganisms from the supralittoral and splash zone in three different rocky locations of the Western Mediterranean coast, a tough environment characterized by high levels of irradiation and large temperature and salinity fluctuations. We have retrieved a complete view of the ecology and functional aspects of these communities and assessed the biotechnological potential of the cultivable microorganisms. All three locations displayed very similar taxonomic profiles, with the genus Rubrobacter and the families Xenoco…
Reliable Detection and Smart Deletion of Malassez Counting Chamber Grid in Microscopic White Light Images for Microbiological Applications
2015
AbstractIn biology, hemocytometers such as Malassez slides are widely used and are effective tools for counting cells manually. In a previous work, a robust algorithm was developed for grid extraction in Malassez slide images. This algorithm was evaluated on a set of 135 images and grids were accurately detected in most cases, but there remained failures for the most difficult images. In this work, we present an optimization of this algorithm that allows for 100% grid detection and a 25% improvement in grid positioning accuracy. These improvements make the algorithm fully reliable for grid detection. This optimization also allows complete erasing of the grid without altering the cells, whic…
Aflatoxins and ochratoxin A in stored barley grain in Spain and impact of PCR-based strategies to assess the occurrence of aflatoxigenic and ochratox…
2011
Contamination of barley by moulds and mycotoxins results in quality and nutritional losses and represents a significant hazard to the food chain. The presence of aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) and ochratoxin A (OTA) in stored barley in Spain has been studied. Species-specific PCR assays were used for detection of Aspergillus flavus, A. parasiticus, A. ochraceus, A. steynii, A. westerdijkiae, A. carbonarius and A. niger aggregate in mycotoxin-positive barley samples at different incubation times (0, 1 and 2 days). Classical enumeration techniques (CFU/g) in different culture media for evaluation of Aspergillus in sections Flavi, Circumdati and Nigri were also used. O…