title: Novel Bartonella infection in northern and southern sea otters (Enhydra lutris kenyoni and Enhydra lutris nereis).
abstract: Since 2002, vegetative valvular endocarditis (VVE), septicemia and meningoencephalitis have contributed to an Unusual Mortality Event (UME) of northern sea otters in southcentral Alaska. Streptococcal organisms were commonly isolated from vegetative lesions and organs from these sea otters. Bartonella infection has also been associated with bacteremia and VVE in terrestrial mammals, but little is known regarding its pathogenic significance in marine mammals. Our study evaluated whether Streptococcus bovis/equinus (SB/E) and Bartonella infections were associated with UME-related disease characterized by VVE and septicemia in Alaskan sea otter carcasses recovered 2004-2008. These bacteria were also evaluated in southern sea otters in California. Streptococcus bovis/equinus were cultured from 45% (23/51) of northern sea otter heart valves, and biochemical testing and sequencing identified these isolates as Streptococcus infantarius subsp. coli. One-third of sea otter hearts were co-infected with Bartonella spp. Our analysis demonstrated that SB/E was strongly associated with UME-related disease in northern sea otters (P<0.001). While Bartonella infection was also detected in 45% (23/51) and 10% (3/30) of heart valves of northern and southern sea otters examined, respectively, it was not associated with disease. Phylogenetic analysis of the Bartonella ITS region allowed detection of two Bartonella species, one novel species closely related to Bartonella spp. JM-1, B. washoensis and Candidatus B. volans and another molecularly identical to B. henselae. Our findings help to elucidate the role of pathogens in northern sea otter mortalities during this UME and suggested that Bartonella spp. is common in sea otters from Alaska and California.
authors.affiliation: Wildlife Health Center, One Health Institute, School of Veterinary Medicine, University of California, Davis, CA 95616, USA. Electronic address: scarrasc@iupui.edu.
authors.forename: Sebastian E
authors.initials: SE
authors.lastname: Carrasco
authors.affiliation: Wildlife Health Center, One Health Institute, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors.forename: Bruno B
authors.initials: BB
authors.lastname: Chomel
authors.affiliation: U.S. Fish and Wildlife Service, Marine Mammals Management, 1011 East Tudor Road, Anchorage, AK 99503, USA.
authors.forename: Verena A
authors.initials: VA
authors.lastname: Gill
authors.affiliation: Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors.forename: Rickie W
authors.initials: RW
authors.lastname: Kasten
authors.affiliation: Center for Comparative Medicine and Transitional Research, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Dr., Raleigh, NC 27606, USA.
authors.forename: Ricardo G
authors.initials: RG
authors.lastname: Maggi
authors.affiliation: Center for Comparative Medicine and Transitional Research, College of Veterinary Medicine, North Carolina State University, 1060 William Moore Dr., Raleigh, NC 27606, USA.
authors.forename: Edward B
authors.initials: EB
authors.lastname: Breitschwerdt
authors.affiliation: Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Byrne
authors.affiliation: Alaska Veterinary Pathology Services, 23834 The Clearing Dr., Eagle River, AK 99577, USA.
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Burek-Huntington
authors.affiliation: Wildlife Health Center, One Health Institute, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; California Department of Fish and Wildlife, Marine Wildlife Veterinary Care and Research Center, 1451 Shaffer Road, Santa Cruz, CA 95060, USA.
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Miller
authors.affiliation: Wildlife Health Center, One Health Institute, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors.forename: Tracey
authors.initials: T
authors.lastname: Goldstein
authors.affiliation: Wildlife Health Center, One Health Institute, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors.forename: Jonna A K
authors.initials: JA
authors.lastname: Mazet
mesh_terms: D000413:Alaska; D000818:Animals; D001473:Bartonella / Q000145:classification* / Q000235:genetics*; D001474:Bartonella Infections / Q000150:complications / Q000382:microbiology*; D002140:California; D004269:DNA, Bacterial / Q000032:analysis; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D004696:Endocarditis / Q000382:microbiology; D005260:Female; D005798:Genes, Bacterial / Q000235:genetics; D006351:Heart Valves / Q000382:microbiology; D006403:Hematologic Tests; D008297:Male; D008969:Molecular Sequence Data; D010041:Otters; D010802:Phylogeny; D012307:Risk Factors; D013290:Streptococcal Infections / Q000150:complications
chemical_list: D004269:DNA, Bacterial; D021903:DNA, Ribosomal Spacer
keywords: Bartonella; Enhydra lutris; Northern sea otter; Southern sea otter; Streptococcus bovis/equinus; Vegetative valvular endocarditis