scholarly journals Current PCR-based methods for the detection of mycotoxigenic fungi in complex food and feed matrices

2020 ◽  
Vol 13 (2) ◽  
pp. 139-150
Author(s):  
H. Ur Rahman ◽  
X. Yue ◽  
Q. Yu ◽  
W. Zhang ◽  
Q. Zhang ◽  
...  
Keyword(s):  
Denaturing Gradient Gel Electrophoresis ◽  
Limit Of Detection ◽  
Control Points ◽  
Isolation And Characterization ◽  
Critical Control Points ◽  
Magnetic Capture ◽  
Pcr Multiplex ◽  
Mycotoxigenic Fungi ◽  
Food And Feed ◽  
Detection Technologies

Mycotoxins are toxic secondary fungal metabolites produced by certain types of filamentous fungi, such as Aspergillus, Fusarium, and Penicillium spp. Mycotoxigenic fungi and their produced mycotoxins are considered to be an important issue in food and feed safety due to their toxic effects like carcinogenicity, immunosuppression, neurotoxicity, nephrotoxicity, and hepatotoxicity on humans and animals. To boost the safety level of food and feedstuff, detection and identification of toxins are essential at critical control points across food and feed chains. Zero-tolerance policies by the European Union and other organizations about the extreme low level of tolerance of mycotoxins contamination in food and feed matrices have led to an increasing interest to design more sensitive, specific, rapid, cost-effective, and safer to use mycotoxigenic fungi detection technologies. Hence, many mycotoxigenic fungi detection technologies have been applied to measure and control toxins contamination in food and feed substrates. PCR-based mycotoxigenic fungi detection technologies, such as conventional PCR, real-time PCR, nested PCR, reverse transcriptase (RT)-PCR, loop-mediated isothermal amplification (LAMP), in situ PCR, polymerase chain reaction-denaturing gradient gel electrophoresis (PCR DGGE), co-operational PCR, multiplex PCR, DNA arrays, magnetic capture-hybridization (MCH)-PCR and restriction fragment length polymorphism (RFLP), would contribute to our understanding about different mycotoxigenic fungi detection approaches and will enhance our capability about mycotoxigenic fungi identification, isolation and characterization at critical control points across food and feed chains. We have assessed the principles, results, the limit of detection, and application of these PCR-based detection technologies to alleviate mycotoxins contamination problem in complex food and feed substrates. The potential application of these detection technologies can reduce mycotoxins in complex food and feed matrices.

On-farm udder health monitoring

2011 ◽  
Vol 39 (02) ◽  
pp. 95-100
Author(s):  
J. C. van Veersen ◽  
O. Sampimon ◽  
R. G. Olde Riekerink ◽  
T. J. G. Lam
Keyword(s):  
Management Practices ◽  
Health Management ◽  
Action Plan ◽  
Real Life ◽  
Health Data ◽  
Control Points ◽  
Udder Health ◽  
Critical Control Points ◽  
On Farm ◽  
Clinical Problems

SummaryIn this article an on-farm monitoring approach on udder health is presented. Monitoring of udder health consists of regular collection and analysis of data and of the regular evaluation of management practices. The ultimate goal is to manage critical control points in udder health management, such as hygiene, body condition, teat ends and treatments, in such a way that results (udder health parameters) are always optimal. Mastitis, however, is a multifactorial disease, and in real life it is not possible to fully prevent all mastitis problems. Therefore udder health data are also monitored with the goal to pick up deviations before they lead to (clinical) problems. By quantifying udder health data and management, a farm is approached as a business, with much attention for efficiency, thought over processes, clear agreements and goals, and including evaluation of processes and results. The whole approach starts with setting SMART (Specific, Measurable, Acceptable, Realistic, Time-bound) goals, followed by an action plan to realize these goals.

Critical Control Points in DPR: Quantifying the Multi-Barrier Approach to Treatment

2015 ◽  
Vol 2015 (14) ◽  
pp. 5477-5488
Author(s):  
Ben Stanford ◽  
Troy Walker ◽  
Stuart Khan ◽  
Shane Snyder ◽  
Cedric Robillot
Keyword(s):  
Control Points ◽  
Critical Control Points

scholarly journals Isolation and Characterization of Nitrate Reducing Bacteria for Conversion of Vegetable-Derived Nitrate to ‘Natural Nitrite’

2021 ◽  
Vol 1 (1) ◽  
pp. 11-23
Author(s):  
Arjun Bhusal ◽  
Peter M. Muriana
Keyword(s):  
Nitrate Reduction ◽  
High Performance ◽  
Limit Of Detection ◽  
Reversed Phase ◽  
Test Tube ◽  
Screening Assay ◽  
Isolation And Characterization ◽  
The Us ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria

In the US, sodium nitrate is used as a preservative and curing agent in processed meats and is therefore a regulated ingredient. Nitrate reducing bacteria (NRB) can convert vegetable nitrate into nitrite allowing green/clean label status in the US as per the USDA-FSIS definition of ‘natural nitrite’. The current ‘in-liquid’ test tube assay for detecting nitrite is not suitable for screening mixtures of bacteria nor is commercial nitrate broth suitable for growth of many Gram (+) bacteria. M17 broth was therefore used to develop M17-nitrate broth to be inclusive of Gram (+) bacteria. An ‘on-agar’ colony-screening assay was developed to detect the conversion of nitrate to nitrite on agar plates and could detect one NRB+ colony among ~300–500 colonies on a single plate. Samples that might have NRB were spread-plated on M17 agar plates, sandwiched with nitrate agar, and after incubation followed with sequential agar overlays containing the reagents used in the nitrate reduction assay; the appearance of red color zones above colonies indicated the presence of nitrite. NRB derived from various samples were confirmed for nitrate conversion and both nitrate and nitrite were quantified by C8 reversed-phase (RP) ion-pairing high performance liquid chromatography (HPLC) analysis (1 ppm limit of detection). Staphylococcus carnosus, a strain commonly used for nitrate reduction, was able to convert 1100 ppm M17-nitrate broth to 917 ppm nitrite. Staphylococcus caprae and Panteoa agglomerans, NRB isolated using the M17-nitrate agar assay, were also able to ferment the same broth to 916 ppm and 867 ppm nitrite, respectively. This is the first report of an on-agar colony screening assay for the detection and isolation of nitrite reducing bacteria allowing NRB to be readily isolated. This may allow for the identification of new bacteria that may have a more efficient process to generate nitrite, and possibly concomitant with production of additional natural antimicrobials, as vegetable nitrite becomes more widely used to prevent spore germination.

Critical control points for foods prepared in households whose members had either alleged typhoid fever or diarrhea

1988 ◽  
Vol 7 (2) ◽  
pp. 123-134 ◽  
Author(s):  
Silvia Michanie ◽  
Frank L. Bryan ◽  
Persia Alvarez ◽  
Auria Barros Olivo ◽  
Aurelio Paniagua
Keyword(s):  
Typhoid Fever ◽  
Control Points ◽  
Critical Control Points

scholarly journals Isolation and Characterization of Replication-Competent Human Immunodeficiency Virus Type 1 from a Subset of Elite Suppressors

2006 ◽  
Vol 81 (5) ◽  
pp. 2508-2518 ◽  
Author(s):  
Joel N. Blankson ◽  
Justin R. Bailey ◽  
Seema Thayil ◽  
Hung-Chih Yang ◽  
Kara Lassen ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Highly Active Antiretroviral Therapy ◽  
Limit Of Detection ◽  
Isolation And Characterization ◽  
Immunodeficiency Virus ◽  
Elite Suppressors ◽  
Hiv 1

ABSTRACT Elite suppressors (ES) are untreated human immunodeficiency virus type 1 (HIV-1)-infected individuals who control viremia to levels below the limit of detection of current assays. The mechanisms involved in this control have not been fully elucidated. Several studies have demonstrated that some ES are infected with defective viruses, but it remains unclear whether others are infected with replication-competent HIV-1. To answer this question, we used a sensitive coculture assay in an attempt to isolate replication-competent virus from a cohort of 10 ES. We successfully cultured six replication-competent isolates from 4 of the 10 ES. The frequency of latently infected cells in these patients was more than a log lower than that seen in patients on highly active antiretroviral therapy with undetectable viral loads. Full-length sequencing of all six isolates revealed no large deletions in any of the genes. A few mutations and small insertions and deletions were found in some isolates, but phenotypic analysis of the affected genes suggested that their function remained intact. Furthermore, all six isolates replicated as well as standard laboratory strains in vitro. The results suggest that some ES are infected with HIV-1 isolates that are fully replication competent and that long-term immunologic control of replication-competent HIV-1 is possible.

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