Abstract
The genus Erysipelothrix (family Erysipelotrichaceae, phylum Firmicutes) comprises facultative anaerobic, gram-positive bacilli of the species E. rhusiopathiae, E. tonsillarum, E. inopinata, E. larvae, and E. piscisicarius.1,2 The most concerning species of this genus is E. rhusiopathiae, which has zoonotic potential,3 and can infect and cause disease (“erysipelas”) in birds and mammals.1,4 In humans, the disease is named “erysipeloid” to avoid confusion with human erysipelas, a cutaneous ailment mainly caused by beta-hemolytic group A streptococci.1,5 In cetaceans, the disease has two main clinical forms: (1) a cutaneous one, characterized by rhomboid lesions (“diamond skin disease”), and (2) a septicemic form, which is often fatal. Erysipelas is considered an important cause of death in captive cetaceans;6 however, information in free-ranging cetaceans is limited7,8.
An adult common bottlenose dolphin (Tursiops truncatus) of unidentified sex was found dead and in advanced autolysis in Paraíba state, northeastern Brazil, on July 19, 2020. Upon gross examination, 80% of the body surface presented multifocal disseminated occasionally ulcerated rhomboid cutaneous lesions ranging from 6–10 cm in diameter, characterized by well-defined edges, consistent with erysipelas lesions. Additionally, postmortem anthropogenic linear cuts and partial mechanical removal of the second third of the flank musculature were noted. Skin samples were collected for histopathologic and molecular analyses. In spite of the advance autolysis of the skin, it was possible to observe the presence of multifocal dermatitis with vasculitis. Infection by Erysipelothrix sp. was confirmed by 16S rRNA gene PCR.9 This bacterium may have played a major role in the stranding and death of this dolphin. Despite previous reports of human consumption of cetacean meat in northeastern Brazil, the observed marks and advanced carcass autolysis suggested the animal was most likely used as bait for fishing instead of human intake.
In South America, E. rhusiopathiae was only reported in two southern right whales (Eubalaena australis) from Argentina,8 and interestingly, Erysipelothrix sp. was recently detected in the intestines of the same species10. This case expands the geographical range and contributes to the current understanding of erysipelas in free-ranging odontocete cetaceans. Further research will be conducted to identify the Erysipelothrix species and characterize surface protective antigen (Spa) proteins present in the bacterium. Due to the zoonotic potential of certain species of Erysipelothrix (i.e., E. rhusiopathiae), active public health policies are required to inform field professionals and the general public about the health threats associated with marine mammal manipulation and consumption.
Acknowledgements
This study was funded by the Coordination for the Improvement of Higher Education Personnel (CAPES) and the São Paulo Research Foundation (FAPESP). All study samples were collected in full compliance with specific federal permits issued by the Chico Mendes Institute for Biodiversity Conservation (ICMBio) and approved by the Biodiversity Information and Authorization System (SISBIO 40072-7). C.S. and A.C.E. are recipients of postdoctoral and PhD fellowships by FAPESP (FAPESP 2016/20956-0 and FAPESP 2018/25069-7, respectively). A.M.S.S. is the recipient of a postdoctoral fellowship (PNPD/CAPES). L.B.K. and J.L.C.-D. are the recipients of a professorship by the National Research Council (CNPq) (grants #312036/2018-3 and #304999/2018, respectively). The authors are grateful to the Environmental Protection Area of the Mamanguape River/ICMBio, Projeto Viva o Peixe-Boi Marinho of the Fundação Mamíferos Aquáticos and sponsored by Petrobras through the Petrobras Socioenvironmental Program and the Manatee Conservation Program of the Fundação Mamíferos Aquáticos in partnership with the Fundação Grupo Boticário de Conservação à Natureza (Boticário Group Foundation for the Conservation of Nature).
*Presenting author
+Student presenter
Literature Cited
1. Wang Q, Chang BJ, Riley TV. 2010. Erysipelothrix rhusiopathiae. Vet Microbiol 140:405–417.
2. LPSN [Internet]. [LPSN] LPSN—List of Prokaryotic names with Standing in Nomenclature (bacterio.net) [cited 2020 Dec 16]. Available from: https://lpsn.dsmz.de/genus/erysipelothrix
3. Waltzek TB, Cortés-Hinojosa G, Wellehan JFJr, Gray GC. 2012. Marine mammal zoonoses: a review of disease manifestations. Zoonoses Public Health 59:521–535.
4. Opriessnig T, Forde T, Shimoji Y. 2020. Erysipelothrix spp.: past, present, and future directions in vaccine research. Front Vet Sci 7:174.
5. Jendoubi F, Rohde M, Prinz JC. 2019. Intracellular Streptococcal uptake and persistence: a potential cause of erysipelas recurrence. Front Med 6:6.
6. Venn-Watson S, Daniels R, Smith C. 2012. Thirty year retrospective evaluation of pneumonia in a bottlenose dolphin Tursiops truncatus population. Dis Aquat Organ 99:237–242.
7. Díaz-Delgado J, Arbelo M, Sierra E, Vela A, Domínguez M, Paz Y, Andrada M, Domínguez L, Fernández A. 2015. Fatal Erysipelothrix rhusiopathiae septicemia in two Atlantic dolphins (Stenella frontalis and Tursiops truncatus). Dis Aquat Org 116:75–81.
8. Fiorito CD, Bentancor A, Lombardo D, Bertellotti M. 2016. Erysipelothrix rhusiopathiae isolated from gull-inflicted wounds in southern right whale calves. Dis Aquat Org 121:67–73.
9. Mignard S, Flandrois JP. 2006. 16S rRNA sequencing in routine bacterial identification: a 30-month experiment. J Microbiol Meth 67:574–581.
10. Marón CF, Kohl KD, Chirife A, Di Martino M, Fons MP, Navarro MA, Beingesser J, McAloose D, Uzal FA, Dearing MD, Rowntree VJ, Uhart M. 2019. Symbiotic microbes and potential pathogens in the intestine of dead southern right whale (Eubalaena australis) calves. Anaerobe 57:107–114.