Evaluation and Microanalysis of Parasitic and Bacterial Agents of Egyptian Fresh Sushi, Salmo salar

• Published in: Microscopy and Microanalysis
• Main Authors: Abdel-Hakeem, Sara S., Mahmoud, Ghada Abd-Elmonsef, Abdel-Hafeez, Hanan H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2019
• Subjects: Instrumentation; Salmo salar
• Online Access: http://dx.doi.org/10.1017/s143192761901506x; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S143192761901506X

Abstract The present study aimed to evaluate the quality of fresh sushi in Egypt. Fifty samples of sushi ( Salmo salar ) were collected from restaurants in Alexandria, Egypt. Paraffin, semi-thin and ultra-thin sections were used for parasitological analysis by l ight and transmission electron microscopy. Bacteria were isolated by the dilution plate and direct plate methods and identified by a Vitek system. Twenty (40%) of the total examined samples showed microsporidia and helminth metacercariae infections. Histochemical stains showed distinct pinkish-red pyriform microspores embedded in muscular tissue stained with Gram, periodic acid-Schiff (PAS), and Ziehl–Neelsen (ZN) stains. Semi-thin sections showed double membrane xenoma-inducing granulomas containing spores at different developmental stages. Empty sporophorous vesicles and free spores were observed in the electron microscopic images. A bacteriological assay showed forty samples (80%) contaminated with human pathogenic bacteria with the average total bacterial counts ranging from 32 to 526 CFU/g. Four species of human pathogenic bacteria were identified in the examined samples, namely Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus , and Serratia plymuthica in 40, 38, 11, and 6 samples, respectively. These constitute the first record of fresh sushi product in Egypt and indicate the potential pathogenicity associated with raw seafood products.