Abstract:

Mediterranean mussels (Mytilus galloprovincialis) (Lamarck, 1819), due to their nutritional mechanisms which involve filtering huge amounts of water, are affected by seawater pollution and can host microbial diversity of environmental origin as well as pathogenic bacteria, which must be constantly monitored. In this study, we applied a Next Generation Sequencing marker gene (16SrDNA) approach for the characterization of the M. galloprovincialis microbiota, collected from mussel farms in the region of Thermaikos gulf, Northern Aegean Sea, Greece. The collection of samples was carried out during the winter months (December 2021 – February 2022), in specific farm zones (Chalastra, Makrigialos), by the official Veterinary service following the appropriate protocol. Totally twelve samples were collected from a 3-8 meters depth, where the temperature was also measured, and within four hours they were transferred to the Veterinary Center of Thessaloniki. 10-12 mussels were selected from each sample and the selected ones had to be alive, adult and of similar size. Then, their shell was opened with a sterile knife, the content (flesh and liquid) was placed in stomacher bags and homogenized for 2 minutes, using the Stomacher device. A microbiological test was also performed using the Most Probable Number (MPN) method for the enumeration of Escherichia coli (according to ISO 16649-3: 2005) and the presence of Salmonella sp. (isolation method using RVS broth and XLD agar). DNA isolation with the DNeasy PowerFood Microbial Kit and amplification of whole 16SrRNA gene ( ̴1500 bp) was conducted with locus specific primers (27F & 1492R), where each sample was marked with a different barcode. Libraries were constructed according to the 16S barcoding kit (Oxford Nanopore Technologies), after pooling all barcodes, for targeted amplicon sequencing. Raw data were base called with algorithms implemented in GUPPY software (Oxford Nanopore Technologies), where reads were demultiplexed according to the used barcodes. Clean sequences were obtained after trimming of barcodes, adapter and primer sequences. Subsequently, they were subjected to EPI2ME Fastq 16S cloud-based bioinformatics workflow (Oxford Nanopore Technologies) for taxonomic classification. The results obtained, showed statistically significant differences between the two sampling regions. More specific, in Makrigialos region the five most abundant genera were Anaplasma (20.9%), Mycoplasma (7.6%), Polaribacter (3.1%), Ruegeria (2.5%) and Rubritalea (1.7%), whereas in Chalastra region the respective ones were Mycoplasma (10.6%), Pseudomonas (3.7%), Mariniblastus (3.4%), Legionella (2.9%) and Rubritalea (2.2%). We hypothesize that different environments generate conditions for specific microorganism growth, reducing competition and favoring the selection of certain genera.

Biography:

My name is Imsiridou Anastasia and I was born in Thessaloniki, Greece, on January 29th 1969. I have a diploma of Biology from the School of Sciences, of the Department of Biology, of the Aristotle University of Thessaloniki. I have a PhD in the Sector of Genetics, Development and Molecular Biology, of the Department of Biology, of the Aristotle University of Thessaloniki with title “Study of the genetic structure of Greek Leuciscus cephalus (L.) populations”. Part of my PhD thesis was held in Centre d’ Analyse Moléculaire de la Biodiversité of the Université Claude Bernard (Lyon, France) with an ERASMUS scholarship. I had been a post-doctoral researcher in the Institute for Systems Informatics and Safety of Joint Research Center, where I worked on a Web based database for genetic identification of stocks of commercially important fish species (Ispra, Italy, April 1998 – July 1999). From December 1999 till August 2003, I worked as an Ichthyologist in the Department of Fisheries of the Thesprotia Prefecture (Greece). From 2003 till 2012 I had been an Assistant Professor in the Department of Fisheries and Aquacultures Technology of Alexander Technological Educational Institute of Thessaloniki and from 2012 till 2014 I had been an Associated Professor in the same Department. From 2014 till today I am a Full Professor in the Department of Food Science and Technology of the International Hellenic University. I am the author of twenty-three articles published in referred Journals, four chapters in books and forty-six conference papers. I am also the author of a scientific book with title: Genetic Analysis Techniques – Applications in Food Sector, ISBN 978-960-6706-67-7, Sofia Publications, Thessaloniki, Greece, which has been published recently. My research interests are focused on: population genetics, genetic study of aquatic organisms, genetic identification of aquatic organisms, genetic identification of food products, food fraud detection with molecular analysis techniques.

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