Assessment of the Health Status of Mussels Mytilus galloprovincialis Along the Campania Coastal Areas: A Multidisciplinary Approach

Abstract

The bivalve Mytilus galloprovincialis has a broad geographic distribution, represent an important species for the ecology of coastal waters, also constituting a major aquaculture species. In the present work, molecular and tissue biomarkers were examined in mussel populations (M. galloprovincialis) located in four different areas of the coastal water of the Campania Region. During an annual life cycle, we analyzed the expression patterns of several genes commonly used to estimate cellular stress response and damage, namely p53, p63, HSP70, MT-10, and MT-20, related tissue lesions (pathogens, inflammations, digestive tubules damage), oxidative stress indicators (H2O2, SOD specific activity) and associated environmental data. The computed Principal Component Analysis showed that the areas were discernible based on the environmental data and biomarker results. About animal health status, mussels from Gulf of Pozzuoli and Naples’s harbor did show a thinnest epithelial cell of digestive tubules compared to mussels sampled from other sampling sites; moreover, high prevalence of cases of intersex in three of the examinated areas were observed. The presence of a potential zoonotic pathogen (Nocardia crassostreae) was identified, appearing as an important possible emerging disease. We also reported the OIE notifiable protozoa Marteilia refringens in three areas out of four. The likely impact of both observed pathogens on the mussel health and shellfish aquaculture needs to be urgently addressed. Results are discussed considering animal histopathological health parameters and biological effects.

The Mediterranean Mussel (Mytilus galloprovincialis) as Intermediate Host for the Anisakid Sulcascaris sulcata (Nematoda), a Pathogen Parasite of the Mediterranean Loggerhead Turtle (Caretta caretta)

“…The Mediterranean mussel has been intensively studied for pathogens in the whole Mediterranean as well as the Campanian coastal areas [19][20][21], but to date, our study describes the first finding of a parasite nematode in this bivalve species. According to McElwain et al [22], parasitic nematodes are uncommon in marine bivalves.…”

Histopathological and Molecular Study of Pacific Oyster Tissues Provides Insights into V. aestuarianus Infection Related to Oyster Mortality

“…Currently, the main methods for the detection of oyster pathogens are based on biomolecular and microbiological techniques. Bivalve histopathology has recently become a crucial tool for disease diagnosis of aquatic organisms, albeit only a few studies have focused on the importance of histopathological investigation to detect the presence of inflammatory reaction, and tissue lesions associated to mollusk pathogens [ 6 , 21 , 42 , 43 , 44 , 45 , 46 , 47 ].…”

Physiological and gene transcription assays to assess responses of mussels to environmental changes

“…Due to the remote nature of the parks and other logistical constraints, sampling opportunities were limited to a one week window in July 2015 and again in July 2016. Other environmental monitoring studies generally have been conducted in areas with known contamination concerns, allowing for a clear contrast among experimental groups (Akaishi et al, 2007; Banni et al, 2017; Carella et al, 2018; Gagné et al, 2007; Halldórsson et al, 2008; Sforzini et al, 2018; Shaw et al, 2011). However, our goal was to develop a method to monitor sites for changes, rather than assess sites already impacted.…”

“…The results of this study examined the strength of using both gene transcription and biomarker assays to evaluate coastal ecosystems. This approach has been implemented for mussel biomonitoring in other coastal regions including the Mediterranean (Carella et al, 2018; Sforzini et al, 2018). In both of these studies, site-level differences were detected using genetic techniques and biomarker analyses.…”

“…The amount of a particular gene that is expressed is physiologically dictated by a number of intrinsic and extrinsic factors, and analysis of mRNA and protein levels can provide information about dynamic changes in the functional state of an organism. A holistic approach that combines biomarker and gene transcription is gaining momentum in other regions, with researchers evaluating and applying these methods to mussels and other invertebrates for environmental monitoring to improve sensitivity and efficiency (Banni et al, 2017; Beyer et al, 2017; Carella et al, 2018; Sforzini et al, 2018). An advantage of measuring gene transcription is that mRNA production is the earliest observable sign an organism is responding to a stressor, but mRNA is generally not as stable as proteins (De Sousa Abreu et al, 2009; McLoughlin et al, 2006).…”