Dolphins and sea turtles may host zoonotic parasites and pathogenic bacteria as indicators of anthropic pressure in the Gulf of Taranto (Northern Ionian Sea, Central-Eastern Mediterranean Sea)

Abstract

The occurrence of protozoan parasites Giardia duodenalis and Cryptosporidium spp. such as the pathogenic bacteria Salmonella spp. and Escherichia coli was molecularly investigated in the following free ranging species of striped dolphins (Stenella coeruleoalba), Risso’s dolphins (Grampus griseus) as well as loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtles living in the Gulf of Taranto (Mediterranean Sea). Out of forty-one investigated individuals belonging to the 4 species, 13 (31.7%) were positive to one or more pathogens and zoonotic G. duodenalis assemblage A, Cryptosporidium parvum and S. enterica were identified in striped dolphins, loggerhead and green sea turtles. In this work, the presence of these opportunistic pathogens has been investigated in fecal samples of free ranging dolphin and sea turtle species for the first time. Moreover, this is the first record of C. parvum in loggerhead sea turtles. These results may provide baseline data for the potential role of cetaceans and sea turtles as potential sentinel species for zoonotic and terrestrial pathogens in the marine environment.

Isolation and Characterization of Cetacean Cell-Derived Extracellular Vesicles

“…or protozoal (e.g., Toxoplasma gondii or Giardia spp.) agents [32][33][34][35]. Also, cetaceans could be relevant hosts for infectious diseases during spill-over events, like those which occurred in the evolution of Cetacean morbillivirus and, more recently, for a highly pathogenic influenza virus [36,37].…”

Bacterial Infections in Sea Turtles

“…Recently, sea turtle fecal samples were collected from 20 loggerhead and 3 green sea turtles found stranded but still alive or caught by fisherman along the Gulf of Taranto (Ionian Sea coast, Italy); one loggerhead and two green sea turtles resulted as PCR-positive for S. enterica [ 65 ].…”

“…A recent study investigated the presence of E. coli O157:H7, a zoonotic enterohaemorrhagic serotype, in C. caretta and C. mydas living in the Gulf of Taranto, but no strains were isolated [ 65 ]. However, other E. coli strains have been associated with some lesions observed in sea turtles, such as necrotizing and granulomatous splenitis and hepatitis, fibrinous perihepatitis, fibrinous and necrotizing enteritis, fibrinous and ulcerative esophagitis, and perinephric abscesses [ 55 ].…”