New insights into the gut microbiome in loggerhead sea turtles Caretta caretta stranded on the Mediterranean coast

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 ho…

Helminth Infection of the Loggerhead Sea Turtle Caretta caretta along the Coasts of Sicily and the North West Adriatic Sea

We provide new data on the presence of helminth parasites in 64 individual loggerhead sea turtles Caretta caretta stranded along the coasts of Sicily and the northwest Adriatic Sea between June 2014 and August 2016. The necropsy examination revealed 31 individuals (48.4%) positive for endoparasites, showing a greater prevalence of trematodes than nematodes. In particular, seven species and a single genus of Trematoda (Hapalotrema) and a single species and genus of Nematoda (Kathlania) were identified. Among the Digenea flukes the species with the highest prevalence of infection were Rhytidodes gelatinosus (34.6%) and Hapalotrema sp. (33.3%), while among the Nematoda they were Kathlania sp. …

New records of leatherback sea turtle, Dermochelys coriacea (Vandelli, 1761) (Testudines: Dermochelyidae) in the Strait of Sicily

We report three new records of leatherback sea turtle, Dermochelys coriacea (Vandelli, 1761) recovered in February 2011 and in spring-summer 2016 in the Strait of Sicily. The individuals were handed over dead to the IZS of Palermo for necropsy. The first specimen measured 139 and 91 cm of CCL and CCW respectively and was found beached and alive but died a few hours later for septicemia. The second measured 110 cm of CCL and 83 cm of CCW and showed a deep wound on its head probably due to contact with a boat propeller. The third individual measured 134 cm of CCL and 96 cm of CCW and had plastic bags, a piece of fishing net and debris of various nature in the stomach. For the second individua…

A new record and molecular characterization of the Green Turtle Chelonia mydas (Testudines, Cheloniidae) in Sicilian coastal waters

A juvenile specimen of the Green Turtle, Chelonia mydas, was recovered in Sicilian coastal waters close to Avola (Syracuse province, south-eastern Sicily, Italy). Before being released, the specimen was measured and inspected for the presence of ingested hooks or other possible harms to its health. A fragment of the mtDNA marker COI was amplified and sequenced in order to provide the first molecular data for the species from the central Mediterranean area. The possible influence of climate change on the occurrence of this thermophilic species in the central Mediterranean area is briefly discussed.

Occurrence of Antibiotic Resistance in the Mediterranean Sea

Seawater could be considered a reservoir of antibiotic-resistant bacteria and antibiotic resistance genes. In this communication, we evaluated the presence of bacterial strains in seawater collected from different coasts of Sicily by combining microbiological and molecular methods. Specifically, we isolated viable bacteria that were tested for their antibiotic resistance profile and detected both antibiotic and heavy metal resistance genes. Both antibiotic-resistant Gram-negative bacteria, Vibrio and Aeromonas, and specific antibiotic resistance genes were found in the seawater samples. Alarming levels of resistance were determined towards cefazolin, streptomycin, amoxicillin/clavulanic aci…

Incidental catch of loggerhead sea turtles (Caretta caretta) along the Sicilian coasts by longline fishery

It has been estimated that 44,000 Caretta caretta turtles die every year due to anthropomorphic activity in the Mediterranean Sea, and that longline fishing is one of the most significant causes of mortality. A total of 482 specimens of C. caretta were rescued from different parts of the Sicilian coast (Mediterranean Sea) from 2014 to 2016. The most numerous stranding was recorded during the spring and summer seasons, mainly along the north and eastern coasts of Sicily. The curved carapace length for all the specimens ranged from between 19 and 95 cm and most of these were young or sub adults. The highest number of strandings was recorded in 2014 and 2015, with 206 and 169 individuals, resp…

Stranding patterns of the striped dolphin (Stenella coeruleoalba , Meyen 1833, Delphinidae) along the Sicilian coast (Mediterranean Sea)

First data on microflora of loggerhead sea turtle (Caretta caretta) nests from the coastlines of Sicily (Italy)

ABSTRACT Caretta caretta is threatened by many dangers in the Mediterranean basin, but most are human-related. The purposes of this research were: (i) to investigate microflora in samples from six loggerhead sea turtle nests located on the Sicilian coast and (ii) to understand microbial diversity associated with nests, with particular attention to bacteria and fungi involved in failed hatchings. During the 2016 and 2018 summers, 456 eggs and seven dead hatchling from six nests were collected. We performed bacteriological and mycological analyses on 88 egg samples and seven dead hatchlings, allowing us to isolate: Fusarium spp. (80.6%), Aeromonas hydrophila (55.6%), Aspergillus spp. (27.2%) …

Is Caretta Caretta a Carrier of Antibiotic Resistance in the Mediterranean Sea?

Sea turtles can be considered a sentinel species for monitoring the health of marine ecosystems, acting, at the same time, as a carrier of microorganisms. Indeed, sea turtles can acquire the microbiota from their reproductive sites and feeding, contributing to the diffusion of antibiotic-resistant strains to uncontaminated environments. This study aims to unveil the presence of antibiotic-resistant bacteria in (i) loggerhead sea turtles stranded along the coast of Sicily (Mediterranean Sea), (ii) unhatched and/or hatched eggs, (iii) sand from the turtles&rsquo

Chasing phthalates in tissues of marine turtles from the Mediterranean sea

Tissues from thirteen specimens of marine turtles, one Dermochelys coriacea and twelve Caretta caretta, found dead along the Sicilian coasts in 2016 were analyzed for the presence of phthalates. Four phthalates (DEP, DBP, BBP, and DEHP) were found at different significant concentrations in liver and gonads, while only DBP was found in muscle tissues and at a fourfold lower concentration than other phthalates in Dermochelys coriacea. No traces of DEP were detected in C. caretta tissues where DOTP was also revealed. The presence of phthalates in fat tissue in specimens of C. caretta showed a major prevalence of the most lipophilic phthalates DEHP and DOTP. The total concentration of all analy…

Nuevo registro y caracterización molecular de la tortuga verde Chelonia mydas (Testudines, Cheloniidae) en las aguas costeras sicilianas

A juvenile specimen of the Green Turtle, Chelonia mydas, was recovered in Sicilian coastal waters close to Avola (Syracuse province, south-eastern Sicily, Italy). Before being released, the specimen was measured and inspected for the presence of ingested hooks or other possible harms to its health. A fragment of the mtDNA marker COI was amplified and sequenced in order to provide the first molecular data for the species from the central Mediterranean area. The possible influence of climate change on the occurrence of this thermophilic species in the central Mediterranean area is briefly discussed.