Caretta caretta is the most common sea turtle species in the Mediterranean Sea. The species is threatened by anthropomorphic activity that causes thousands of deaths and hundreds of strandings along the Mediterranean coast. Stranded turtles are often cared for in rehabilitation centres until they recover or die. The objective of this study was to characterize the gut microbiome of nine sea turtles stranded along the Sicilian coast of the Mediterranean Sea using high-throughput sequencing analysis targeting V3–V4 regions of the bacterial 16S rRNA gene. Stool samples were collected from eight specimens hosted in the recovery centre after a few days of hospitalization (under 7) and from one hosted for many weeks (78 days). To better explore the role of bacterial communities in loggerhead sea turtles, we compared our data with published fecal microbiomes from specimens stranded along the Tuscan and Ligurian coast. Our results highlight that, despite the different origin, size and health conditions of the animals, Firmicutes, Bacteroidetes and Proteobacteria constitute the main components of the microbiota. This study widens our knowledge on the gut microbiome of sea turtles and could be helpful for the set up of rehabilitation therapies of stranded animals after recovery in specialized centres.

Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system, caused by a combination of genetic and environmental factors. In recent years, a role in MS pathogenesis was assigned to the gut microbiota. However, different signatures of gut dysbiosis have been shown to depend on environmental factors, like diet and lifestyle. In this study, we compared the gut microbiome in MS patients and their household healthy relatives sharing lifestyle and environmental factors. Faecal metagenomic DNA was extracted and the V3–V4 regions of the conserved bacterial 16S ribosomal RNA gene were amplified and sequenced. While overall bacterial communities were similar, specific families differed between healthy and MS subjects. We observed an increase in Ruminococcaceae, Christensenellaceae, Desulfovibrionaceae, Clostridiales, and Family XIII in MS patients, while Bacteroidaceae, Tannerellaceae, Veillonellaceae, and Burkholderiaceae were more abundant in healthy controls. In addition, principle coordinate analysis showed that the gut microbiome of all MS patients formed a cluster being less diverse than the household relatives and that gut microbiota of MS patients with EDSS 4.5–7 formed a distinct cluster in respect to their controls. Overall, our study is consistent with the hypothesis that MS patients have gut microbial dysbiosis and evidenced the importance of environmental factors in shaping the gut microbiome.

In this study, we evaluated the microbiome and the resistome profile of water and fragments of polyethylene (PE) waste collected at the same time from a stream and the seawater in a coastal area of Northwestern Sicily. Although a core microbiome was determined by sequencing of the V3–V4 region of the bacterial 16S rDNA gene, quantitative differences were found among the microbial communities on PE waste and the corresponding water samples. Our findings indicated that PE waste contains a more abundant and increased core microbiome diversity than the corresponding water samples. Moreover, PCR analysis of specific antibiotic resistance genes (ARGs) showed that PE waste harbors more ARGs than the water samples. Thus, PE waste could act as a carrier of antibiotic-resistant microbiota, representing an increased danger for the marine environment and living organisms, as well.

The loggerhead sea turtle, Caretta caretta (Linnaeus, 1758), is the most common sea turtle species in the Mediterranean Sea, where it can experience severe anthropogenic impacts. Although C. caretta is known to host more than 200 epibiotic taxa (crustaceans, algae and cyanobacteria), no reports have included a detailed evaluation of the microbial community of its carapace scutes. Thus, this study aimed to determine the diversity and composition of the visible and invisible communities on the carapace scutes of wild loggerhead turtles from the Aeolian Archipelago (Southern Tyrrhenian Sea, Italy) by using a combined approach of morphological/spatial examination and molecular analyses. Altogether, our results displayed a higher abundance of crustaceans, macroalgae and Proteobacteria on the posterior carapace scutes, while Firmicutes were more abundant on the anterior scutes. For the first time, this study showed the complexity of the microbial (invisible) and visible epibionts of the loggerhead sea turtles from the Mediterranean Sea and suggests the importance of including evaluation of the microbial components when studying epibiont communities.

The Maghreb region of North Africa, located at the intersection of the Palaearctic and Afrotropical zones, is a biodiversity hotspot for terrestrial and freshwater taxa, including the freshwater crab of genus Potamon Savigny, 1816. Recent molecular studies have suggested the presence of two distinct Potamon species in the region: Potamon algeriense Bott, 1967, and an as-yet undescribed taxon, Potamon sp. However, comprehensive data on their distribution, genetic structure, and conservation status are still lacking. In the present study, we integrate new field collections from Algeria and Morocco (2021–2023) with molecular analyses of mitochondrial (COI, ND1) and nuclear (28S rDNA) markers to assess species boundaries and genetic diversity within Potamon across the Maghreb. Phylogenetic reconstructions based on Maximum Likelihood and Bayesian Inference consistently support the presence of two well-differentiated Potamon lineages in the region, corresponding to P. algeriense in western and central Maghreb, and Potamon sp. in eastern Algeria and Tunisia. While Potamon sp. exhibits low intra-specific genetic variation, P. algeriense displays a deeply structured mitochondrial lineage composition, forming four geographically coherent subclades, each corresponding to distinct hydrological regions. In light of this, it would be advisable to revise the IUCN assessment to include both species and updated information on their distribution.