Serologic Survey of Brucella Spp. Antibodies in Some Marine Mammals of North America

Abstract

A serologic survey of anti-Brucella spp. antibodies was undertaken on 2,470 samples of 14 North American marine mammal species collected between 1984-97. Serum or blood from eight species of cetaceans and six species of pinnipeds was sampled from Pacific, Atlantic, and Arctic oceans. Two competitive enzyme-linked immunosorbent assays (C-ELISA's), using specific monoclonal antibodies to Brucella abortus cell wall components, were used to detect anti-Brucella spp. antibodies in the samples. Sera from 33 cetaceans and 61 pinnipeds gave inhibition values, in one or both of the tests, which exceeded the threshold that indicates Brucella spp. exposure in cattle. Seropositive animals were identified from Pacific, Atlantic, and Arctic oceans. While Brucella spp. was not isolated, differences in the response of seropositive cetacean and pinniped sera in the two assays suggest that two antigenically distinct species or biovars of Brucella spp. are present. No pathology consistent with clinical brucellosis was noted in any of the animals tested although detailed examination was not conducted on all carcasses.

A multiplex real-time polymerase chain reaction assay with two internal controls for the detection of Brucella species in tissues, blood, and feces from marine mammals

“…To date, however, no definitive evidence of associated pathologic change has been described in this taxonomic group, suggesting that the presence or absence of Brucella-specific antibodies alone may not adequately assess infection status in individuals or populations of pinnipeds. 26,31 Inconsistent seroconversion with known infection has been observed. 18 Clinical interpretation of positive titers in stranded pinnipeds during rehabilitation or in captive populations is obfuscated by the absence of detectable disease.…”

“…19,26,30 Clinical manifestations of brucellosis in marine mammals are so far described only in cetaceans, with abortion and placentitis, orchitis, visceral and blubber abscesses, musculoskeletal lesions, and meningoencephalitis reported. 12,20,27 High levels of seropositivity are frequently reported in pinnipeds, and microbiologic isolation is reported in many pinniped species.…”

“…documented in many cetacean, pinniped, and marine carnivore species. 14,26,27 Brucella pinnipedialis and Brucella ceti have been proposed as formal names for isolates from pinnipeds and cetaceans, respectively, based on metabolic differences in culture and genetic analyses. 11 Other genetic studies support 3 distinct lineages with associated host preferences for pinnipeds, dolphins, and porpoises, although host specificity is not absolute.…”

Exposure of harbour seals Phoca vitulina to Brucella in declining populations across Scotland

“…Similar to this study, Brucella antibodies have been detected in sera from a number of marine mammal species using Rose Bengal tests (Tryland et al 1999, Retamal et al 2000, Hernández-Mora et al 2008, Jensen et al 2013, and using both indirect ELISA (iELISA) and cELISAs primarily designed for ruminants (Tryland et al 1999, Nielsen et al 2001, Van Bressem et al 2001, Tachibana et al 2006, Roe et al 2010, Lynch et al 2011, Jensen et al 2013, Nymo et al 2013a). Here, differences in the prevalence estimates obtained from the RBT and the cELISA results highlight the need to consider test performance when conducting serological studies.…”

Exposure to Novel Parainfluenza Virus and Clinical Relevance in 2 Bottlenose Dolphin (Tursiops truncatus) Populations

“…Although ELISA is the ideal tool for identifying infections caused by PIV, high levels of antigenic cross-reactivity among various PIV subfamilies and other closely related viruses hinder the ability for ELISA to determine which type of PIV has infected an animal (10,11). In wild marine mammal populations, ELISA-based serosurveys for suspected viral or bacterial pathogens are common (12)(13)(14). Limitations of these studies include unknown health status of animals or lack of paired samples that can differentiate exposures from active infections.…”