Abstract
Consuming contaminated seafood can lead to various bacterial illnesses, either from contamination at the source or during processing and distribution. These illnesses can result from bacterial infection or the ingestion of toxins formed in the food before consumption. However, the distinction between the two causes is not always straightforward. For instance, toxins from Clostridium botulinum and Staphylococcus aureus are preformed in food during bacterial growth, while the toxin from Clostridium perfringens is usually formed when the bacteria sporulate in the intestinal tract. Moreover, the toxin from Vibrio cholerae O1 (and O139) is generated as the bacteria multiply in the intestinal tract. Scombrotoxin, a common illness linked to seafood consumption, is caused by the production of histamine and potentially related substances by certain types of Gram-negative bacteria on histidine-rich fish tissue. This topic is examined in greater detail in another chapter of this book, and therefore will not be extensively discussed here. This paper will explore the various types of bacteria that can lead to illness in humans after consuming seafood, the reported incidence of such infections in specific countries with available data. It will also examine both conventional and molecular methods for detecting, identifying, and categorizing these bacteria. There is growing interest in vibrios as the cause of bacterial illnesses linked to the consumption of bivalve molluscan shellfish and other seafood varieties, with a specific focus on this bacterial group.

Key words: Food safety; foodborne pathogens; microbial diversity; pathogenic bacteria; seafood; spoilage