Haemolymph of blue crab (Callinectes sapidus) as a reservoir of bacteria potentially pathogenic to humans: public health implications

This study investigates bacterial species with potential human health implications isolated from blue crab (Callinectes sapidus) in the Northern Adriatic Sea (Italy). The primary objectives include the preliminary characterization of Vibrio, Shewanella, and other pathogenic bacteria, examining their healthcare-related implications, and providing insights into their epidemiology. Morphometric and cluster analyses revealed significant variations in bacterial prevalence across sampling months and crab sizes, with Vibrio parahaemolyticus being the most abundant species, reaching its highest prevalence in the September samples. Logistic regression indicated that crab length and sampling month were significant factors influencing bacterial isolation, whereas weight and sex had minimal effects. Antibiotic resistance profiles showed widespread resistance to ampicillin and amoxicillin among several bacterial genera, including Vibrio and Shewanella. Shewanella algae, though less prevalent than Vibrio, demonstrated intrinsic resistance to beta-lactams, aligning with its known pathogenic potential in humans. Seasonal variations and environmental changes, such as rising temperatures and salinity, may exacerbate the prevalence and resistance of these pathogens, increasing risks associated with seafood-borne illnesses. This study highlights the need for further research to understand the interactions between environmental changes, bacterial ecology, and human health risks. Implementing proper seafood handling, cooking practices, and personal protective measures can mitigate potential hazards. These results provide the basis for future studies on bacterial epidemiology and guide strategies for the sustainable management of aquatic ecosystems and seafood safety.