Detection of specific antibodies to morbilliviruses, Brucella and Toxoplasma in the Black Sea dolphin Tursiops truncatus ponticus and the beluga whale Delphinapterus leucas from the Sea of Okhotsk in 2002–2007

Serological Detection of Causative Agents of Infectious and Invasive Diseases in the Beluga Whale Delphinapterus leucas (Pallas, 1776) (Cetacea: Monodontidae) from Sakhalinsky Bay

“…The use of CDV antigens instead of CeMV antigens is correct due to the extremely high immunological cross-reactivity between the Morbillivirus species [5,28]. Comparison of results of the present study with published data [1,2] showed that the flood of the Amur River did not influence the level of the CeMV infection.…”

“…The beluga whale can be infected with T. gondii by several routes: alimentary (via water), percutaneous (as a result of skin injuries from contacts with seal claws and body scrub while molting and in search for food in the shallows), and transplacental (from mother to fetus). The proportion of individuals that were seropositive for T. gondii increased in 2013-2014 by a factor of 2.5 compared to 2002-2007 (4.8%) and by a factor of 1.5 compared to 2007-2009 (7.7%) [1,2]. This may be connected with the increased human population on the Chinese coast of the Amur River accompanied by the growth in number of domestic animals.…”

“…The most likely path of infection of beluga whales is via the fecal-oral route, in which the feces of terrestrial mammals dissolved in fresh water are transferred to the estuarine areas. According to earlier data, the average annual level of Brucella-seropositive beluga whales in Sakhalinsky Bay was 13.6% in 2002-2007 and 13.2% in 2007-2009 [1,2]. As a result of the 2013 flood, the agricultural lands in the Amur River basin were flooded, consequently leading to an outbreak of Brucella infection in beluga whales; the proportion of immune individuals increased to 61.5%.…”

“…The duration of the analysis varied from 100 to 140 min in accordance with the test-system manual; 100 μL of the diluted serum was placed in a well. 1 The sample was considered positive if all 1 : 40 dilution replicates were found positive; the mean values of successive dilutions formed a monotonous decreasing succession.…”

“…When using the beluga whale as an indicator species to assess the state of marine Arctic ecosystems, the tested parameters are spatial distribution, population structure, an individual's hormonal status, and the presence of xenobiotics in tissues (including anthropogenic pollutants), as well as the occurrence of invasions and infections of various etiologies [9,18]. An array of pathogens have been reported to circulate in cetacean populations: Brucella and Toxoplasma species [1,2], mycobacteria [25], cetacean morbillivirus (CeMV) [5,15], Otariidae adenovirus (OtAdV) 1 [5,19], influenza A virus [5,13], beluga whale coronavirus SW1 (BWCoV SW1) [5,29], vesicular exanthema MICROBIOLOGY of swine virus (VESV) 2 [5,26], beluga whale herpes virus (BWHV) [14], Phocoena spinipinnis papillomavirus (PsPV) [5], and cetacean poxvirus 1 (CPV-1) [5,16].…”