Meningoencephalitis and Listeria monocytogenes, Toxoplasma gondii and Brucella spp. coinfection in a dolphin in Italy

Abstract

Listeria monocytogenes, Toxoplasma gondii and Brucella spp. can infect a wide range of species, including humans. In cetaceans, meningoencephalitis has been associated with T. gondii and Brucella spp. infection, whereas to our knowledge, L. monocytogenes infection has not previously been reported. Meningoencephalitis and L. monocytogenes, T. gondii and Brucella spp. were identified by means of both direct and indirect laboratory techniques in an adult female striped dolphin Stenella coeruleoalba found stranded in January 2015 on the Ligurian Sea coast, northwestern Italy. The animal was emaciated, and histopathology disclosed severe meningoencephalitis. The nature of the inflammatory response and intra-lesional protozoa were consistent with a mixed infection by L. monocytogenes, T. gondii and Brucella spp. We believe this is an unprecedented case of infection by 3 zoonotic pathogens and also the first bacteriologically confirmed case report of neurolisteriosis in cetaceans. Cerebral toxoplasmosis and neurobrucellosis may have led to the animal's disorientation and stranding, with L. monocytogenes having likely exacerbated the coinfection leading to the demise of this dolphin. KEY WORDS: Meningoencephalitis · Toxoplasmosis · Listeriosis · Brucellosis · Stenella coeruleoalbaResale or republication not permitted without written consent of the publisher

Molecular, serological, pathological, immunohistochemical and microbiological investigation ofBrucellaspp. in marine mammals of Brazil reveals new cetacean hosts

“…We detected coinfection by marine Brucella and other pathogens, as reported before for several cetacean species infected by Brucella and CeMV (West et al, ), E. tarda (Dawson, Perrett, Young, Davison, & Monies, ), T. gondii (Alba et al, ) or T. gondii and Listeria monocytogenes (Grattarola et al, ). In this study, a stranded female calf Guiana dolphin (case # 8), previously identified as infected by a novel lineage of CeMV (Groch et al, ), was positive for Brucella sp.…”

“…Additionally, the Guiana dolphin (case # 8) and an adult male stranded Clymene dolphin (case # 10), the latter serologically positive, presented CNS findings which diverged from Brucella ‐type lesions as previously described (González et al, ; Hernández‐Mora et al, ; Muñoz et al, ), suggesting potential bacterial infections/coinfections as the cause of the CNS suppurative inflammation (Grattarola et al, ). Complete blood count (CBC) analysis in case # 10 (data not shown) supported an acute bacterial infection.…”

Parasite Load and STRs Genotyping of Toxoplasma gondii Isolates From Mediterranean Mussels (Mytilus galloprovincialis) in Southern Italy

“…Special interest has recently been focused on the spillover of pathogens from regional terrestrial animals into the aquatic ecosystem since many typical terrestrial pathogens of zoonotic interest have been found in different classes of marine organisms increasing the reports of lethal cases of infection in marine mammals (Miller et al, 2004;VanWormer et al, 2014;Grattarola et al, 2016;Aguirre et al, 2019;Santoro et al, 2019a).…”

Postmortem Findings in Cetaceans Found Stranded in the Pelagos Sanctuary, Italy, 2007–14

“…Brucella spp. recovered from sea mammals were first reported in 1994 (Ross et al 1994); since then, several cases of placentitis, abortion, and encephalitis in different marine mammal species (Grattarola et al 2016) have been described (Miller et al 1999;Sierra et al 2014). But marine mammals are also often affected by human activities, including chemical pollution from waste discharge (urban, industrial, and agricultural), acoustic pollution by maritime traffic, vessel collisions, and fishing activities (Arbelo et al 2013;Moore et al 2013).…”