Monoamine-containing structures in the intestines of bivalve molluscs and a polychaete annelid revealed by fluorescence histochemistry

In recent years some of the blood cells of several molluscs and insects are characterised as immunocytes. Similar cells from a few invertebrates from India have been looked into under conventional TEM to register the ultrastructural features. This type of study is first of its kind in the subcontinent. Immunocytes from bivalve molluscs Meretrix meretrix, Laroellidens marqinalis and two insect species, apterygote Ctenolepism a longicaudata and pterygote Gesonula punctifrons provide a new set of fine structural information which forms a basis of comparison with those studied earlier.Immunocytes have been collected from the fresh live species of bivalve molluscs and insects obtained locally at Calcutta. These were fixed in icecold 2% glutaraldehyde in 0.1M phosphate buffer (pH 7.2-7.4) for 1-2 hours at 4-5°C. Subseguently pellets were post-osmicated in 1% OsO4 at room temperature for 1-2 hours. Following dehydration these were embedded in Araldite mixture in plastic capsules and polymerization was effected for 2 days at 60°C. Ultrathin sections were cut in a ultrotome and sections were double stained with Uranyl acetate and lead citrate. These were viewed in a TEM.

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Meeting the Salinity Requirements of the Bivalve Mollusc Crassostrea gigas in the Depuration Process and Posterior Shelf-Life Period to Improve Food Safety and Product Quality

Water ◽

10.3390/w13081126 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1126

Author(s):

João A. Silvestre ◽

Sílvia F. S. Pires ◽

Vitória Pereira ◽

Miguel Colaço ◽

Ana P. L. Costa ◽

...

Keyword(s):

Food Safety ◽

Shelf Life ◽

Crassostrea Gigas ◽

Storage Period ◽

Microbiological Contamination ◽

Bivalve Molluscs ◽

Antioxidant Defences ◽

Life Period ◽

Microbiological Analyses ◽

Depuration Process

Microbiological contamination of bivalve molluscs is one of the major concerns inherent to food safety, thus depuration is frequently needed to assure food safety levels associated with their consumption. Salinity plays an important role in the metabolic activity of bivalves and as such can influence their depuration capacity. This study aimed to evaluate the effect of salinity (25, 30, 35 and 40) on the efficiency of the depuration process, along with the quality and shelf-life of Crassostrea gigas. For this, a 24-h depuration was carried out, followed by a storage period at 5 ± 1 °C for six days. Microbiological analyses and biochemical parameters related to oxidative stress response were analysed. Escherichia coli load was reduced in only 24 h, disregarding the salinity of the system. After the shelf-life period, the activity of the antioxidant defences at salinities 35 and 40 is higher but is still not sufficient to avoid lipid peroxidation. Over time, there is a decrease in oyster metabolism probably due to being chilled and to the action of exposure to air. In sum, this study suggests salinities between 25 and 30 as preferential for the depuration process of C. gigas and subsequent quality during shelf-life.

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Evaluation of Two Real Time RT-PCR Methods for Norovirus GI and GII Detection in Live Bivalve Molluscs

Journal of Biotechnology ◽

10.1016/j.jbiotec.2010.09.891 ◽

2010 ◽

Vol 150 ◽

pp. 541-541

Author(s):

E. Suffredini ◽

L. Cozzi ◽

G. Ciccaglioni ◽

L. Croci

Keyword(s):

Real Time ◽

Bivalve Molluscs ◽

Rt Pcr

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Thermal processing of live bivalve molluscs for controlling viruses: On the need for a risk-based design

Critical Reviews in Food Science and Nutrition ◽

10.1080/10408398.2017.1338246 ◽

2017 ◽

Vol 58 (16) ◽

pp. 2854-2865 ◽

Cited By ~ 3

Author(s):

Winy Messens ◽

Pablo S. Fernandez-Escamez ◽

David Lees ◽

Roland Lindqvist ◽

Michael O’Mahony ◽

...

Keyword(s):

Thermal Processing ◽

Bivalve Molluscs

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Prevalence of enterovirus and hepatitis A virus in bivalve molluscs from Galicia (NW Spain): inadequacy of the EU standards of microbiological quality

International Journal of Food Microbiology ◽

10.1016/s0168-1605(01)00744-9 ◽

2002 ◽

Vol 74 (1-2) ◽

pp. 119-130 ◽

Cited By ~ 63

Author(s):

J Romalde

Keyword(s):

Hepatitis A ◽

Hepatitis A Virus ◽

Microbiological Quality ◽

Bivalve Molluscs ◽

Nw Spain ◽

The Eu

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Assessment of a Semiquantitative Liquid Chromatography- Fluorescence Detection Method for the Determination of Paralytic Shellfish Poisoning Toxin Levels in Bivalve Molluscs from Great Britain

Journal of AOAC International ◽

10.5740/jaoacint.13-381 ◽

2014 ◽

Vol 97 (2) ◽

pp. 492-497 ◽

Cited By ~ 3

Author(s):

Andrew D Turner ◽

Monika Dhanji-Rapkova ◽

Clothilde Baker ◽

Myriam Algoet

Keyword(s):

Great Britain ◽

Fluorescence Detection ◽

Detection Method ◽

Reference Method ◽

Paralytic Shellfish Poisoning ◽

Official Method ◽

Shellfish Poisoning ◽

Bivalve Molluscs ◽

Paralytic Shellfish

Abstract AOAC Official Method 2005.06 precolumn oxidation LC-fluorescence detection method has been used for many years for the detection and quantitation of paralytic shellfish poisoning (PSP) toxins in bivalve molluscs. After extensive single- and multiple-laboratory validation, the method has been slowly gaining acceptance worldwide as a useful and practical tool for official control testing. In Great Britain, the method has become routine since 2008, with no requirement since then for reverting back to the bioassay reference method. Although the method has been refined to be semiautomated, faster, and more reproducible, the quantitation step can be complex and time-consuming. An alternative approach was developed to utilize the qualitative screening results for generatinga semiquantitative results assessment. Data obtained over 5 years enabled the comparison of semiquantitative and fully quantitative PSP results in over 15 000 shellfish samples comprising eight different species showed that the semiquantitative approach resulted in over-estimated paralytic shellfish toxin levels by an average factor close to two in comparison with the fully quantified levels. No temporal trends were observed in the data or relating to species type, with the exception of surf clams. The comparison suggested a semiquantitative threshold of 800 μg saxitoxin (STX) eq/kg should provide a safe limitfor the determination of samples to be forwarded to full quantitation. However, the decision was taken to halve this limit to include an additional safety factor of 2, resulting in the use of a semiquantitative threshold of 400 μg STX eq/kg. Implementation of the semiquantitative method into routine testing would result in a significant reduction in the numbers of samples requiring quantitation and have a positive impact on the overall turnaround of reported PSP results. The refined method would be appropriate for any monitoring laboratory faced with high throughput requirements.

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