Evidence of Brucella strain ST27 in bottlenose dolphin ( Tursiops truncatus ) in Europe

Cvetnić, Željko; Duvnjak, Sanja; Đuras, Martina; Gomerčić, Tomislav; Reil, Irena; Zdelar-Tuk, Maja; Špičić, Silvio

doi:10.1016/j.vetmic.2016.10.013

Cited by 17 publications

(18 citation statements)

References 25 publications

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“…02611), with no zoonotic link, an isolate from an aborted dolphin ( Brucella sp. F5/99), and isolates from a stranded bottlenose dolphin from the Adriatic Sea ( Cvetnić et al 2016 ) define a distinct cluster ( Maquart et al 2009 ) herein named cluster H.…”

Section: Resultsmentioning

confidence: 99%

Brucella Genetic Variability in Wildlife Marine Mammals Populations Relates to Host Preference and Ocean Distribution

Suárez-Esquivel

Baker

Ruíz-Villalobos

et al. 2017

Genome Biology and Evolution

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Intracellular bacterial pathogens probably arose when their ancestor adapted from a free-living environment to an intracellular one, leading to clonal bacteria with smaller genomes and less sources of genetic plasticity. Still, this plasticity is needed to respond to the challenges posed by the host. Members of the Brucella genus are facultative-extracellular intracellular bacteria responsible for causing brucellosis in a variety of mammals. The various species keep different host preferences, virulence, and zoonotic potential despite having 97–99% similarity at genome level. Here, we describe elements of genetic variation in Brucella ceti isolated from wildlife dolphins inhabiting the Pacific Ocean and the Mediterranean Sea. Comparison with isolates obtained from marine mammals from the Atlantic Ocean and the broader Brucella genus showed distinctive traits according to oceanic distribution and preferred host. Marine mammal isolates display genetic variability, represented by an important number of IS711 elements as well as specific IS711 and SNPs genomic distribution clustering patterns. Extensive pseudogenization was found among isolates from marine mammals as compared with terrestrial ones, causing degradation in pathways related to energy, transport of metabolites, and regulation/transcription. Brucella ceti isolates infecting particularly dolphin hosts, showed further degradation of metabolite transport pathways as well as pathways related to cell wall/membrane/envelope biogenesis and motility. Thus, gene loss through pseudogenization is a source of genetic variation in Brucella, which in turn, relates to adaptation to different hosts. This is relevant to understand the natural history of bacterial diseases, their zoonotic potential, and the impact of human interventions such as domestication.

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Section: Resultsmentioning

confidence: 99%

Brucella Genetic Variability in Wildlife Marine Mammals Populations Relates to Host Preference and Ocean Distribution

Suárez-Esquivel

Baker

Ruíz-Villalobos

et al. 2017

Genome Biology and Evolution

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“…Similar Th2 immune response was observed in other studies that evaluated the expression of cytokines in different cetacean tissues ( Jaber et al, 2010 ). A variety of infections caused by intracellular pathogens in cetaceans have been reported and may be associated with the mass stranding events of cetaceans ( Cvetnic et al, 2016 ; Domingo et al, 1990 ; Domingo et al, 1992 ; Dubey et al, 2007 ; Dubey et al, 2008 ; Mazzariol et al, 2016 ; Mazzariol et al, 2017 ). In addition, previous studies suggested that Ag contamination exists in all aspects of the marine ecosystem, and cetaceans may have been negatively affected by Ag contamination ( Becker et al, 1995 ; Caceres-Saez et al, 2013 ; Chen et al, 2017 ; Dehn et al, 2006 ; Kunito et al, 2004 ; Li et al, 2018a ; Mendez-Fernandez et al., 2014 ; Reed et al, 2015 ; Rosa et al, 2008 ; Seixas et al, 2009 ; Woshner et al, 2001 ).…”

Section: Discussionmentioning

confidence: 99%

Th2 cytokine bias induced by silver nanoparticles in peripheral blood mononuclear cells of common bottlenose dolphins (Tursiops truncatus)

Wang

Chang

et al. 2018

PeerJ

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BackgroundSilver nanoparticles (AgNPs) have been widely used in many commercial products due to their excellent antibacterial ability. The AgNPs are released into the environment, gradually accumulate in the ocean, and may affect animals at high trophic levels, such as cetaceans and humans, via the food chain. Hence, the negative health impacts caused by AgNPs in cetaceans are of concern. Cytokines play a major role in the modulation of immune system and can be classified into two types: Th1 and Th2. Th1/Th2 balance can be evaluated by the ratios of their polarizing cytokines (i.e., interferon [IFN]-γ/Interleukin [IL]-4), and animals with imbalanced Th1/Th2 response may become more susceptible to certain kinds of infection. Therefore, the present study evaluated the in vitro cytokine responses of cetacean peripheral blood mononuclear cells (cPBMCs) to 20 nm citrate-AgNPs (C-AgNP20) by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR).MethodsBlood samples were collected from six captive common bottlenose dolphins (Tursiops truncatus). The cPBMCs were isolated and utilized for evaluating the in vitro cytokine responses. The cytokines evaluated included IL-2, IL-4, IL-10, IL-12, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α. The geometric means of two housekeeping genes (HKGs), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and β2-microglobulin (B2M), of each sample were determined and used to normalize the mRNA expression levels of target genes.ResultsThe ratio of late apoptotic/necrotic cells of cPBMCs significantly increased with or without concanavalin A (ConA) stimulation after 24 h of 10 µg/ml C-AgNP20 treatment. At 4 h of culture, the mRNA expression level of IL-10 was significantly decreased with 1 µg/ml C-AgNP20 treatment. At 24 h of culture with 1 µg/ml C-AgNP20, the mRNA expression levels of all cytokines were significantly decreased, with the exceptions of IL-4 and IL-10. The IFN-γ/IL-4 ratio was significantly decreased at 24 h of culture with 1 µg/ml C-AgNP20 treatment, and the IL-12/IL-4 ratio was significantly decreased at 4 or 24 h of culture with 0.1 or 1 µg/ml C-AgNP20 treatment, respectively. Furthermore, the mRNA expression level of TNF-α was significantly decreased by 1 µg/ml C-AgNP20 after 24 h of culture.DiscussionThe present study demonstrated that the sublethal dose of C-AgNP20 (≤1 µg/ml) had an inhibitory effect on the cytokine mRNA expression levels of cPBMCs with the evidence of Th2 cytokine bias and significantly decreased the mRNA expression level of TNF-α. Th2 cytokine bias is associated with enhanced immunity against parasites but decreased immunity to intracellular microorganisms. TNF-α is a contributing factor for the inflammatory response against the infection of intracellular pathogens. In summary, our data indicate that C-AgNP20 suppresses the cellular immune response and thereby increases the susceptibility of cetaceans to infection by intracellular microorganisms.

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“…Only MLST method gave the final determination that this strain was Brucella ceti ST27. This is the first record of brucellosis in a dolphin in the Adriatic Sea, and the first record of the strain ST27 in Europe, which also presents a human health risk [18], (Figure 8). …”

Section: Brucellosis In Marine Mammals In the Republic Of Croatiamentioning

confidence: 77%

“…Infected or exposed animals have been found along the Atlantic and Pacific coasts of North America, the coast of Peru, Australia, New Zealand and Hawaii, on the Solomon Islands, and in the Antarctic [14][15][16][17]. The most recent research has also proven the presence of brucellosis in the bottlenose dolphin in Croatia, in the northern Adriatic Sea [18].…”

Section: Distribution Of Brucellosis In Marine Mammalsmentioning

confidence: 99%

Brucellosis in marine mammals, with special emphasis on the Republic of Croatia

Cvetnić¹,

Duvnjak²,

Đuras³

et al. 2017

Rad Hrvatske akademije znanosti i umjetnosti

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SummaryAfter almost two decades of research and evidence of brucellosis in marine mammals, it has become widely known that this disease is prevalent in marine mammals on a global scale. Positive animals have been found in the northern Atlantic, Mediterranean Sea and in the Arctic, including the Barents Sea. Infected or exposed animals have been detected along the Atlantic and Pacific coasts of North America, off the coasts of Peru, Australia, New Zealand, Hawaii, the Solomon Islands, and in the Antarctic Ocean. Brucellosis most commonly occurs in the harbour porpoise (Phocoena phocoena), followed by the striped dolphin (Stenella coeruleoalba), Atlantic white-sided dolphin (Lagenorhynchus acutus), bottlenose dolphin (Tursiops truncatus), shortbeaked common dolphin (Delphinus delphis) and minke whale (Balaenoptera acutorostrata). A positive serological reaction has been confirmed in 35 species of whales and 14 species of seals, two subspecies of sea otters, one species of freshwater otter and the polar bear. To date, brucellosis has been found in marine mammals in the Mediterranean Sea in Italy and Spain. The first research on brucellosis in dolphins in the Republic of Croatia began in 2015. Brucella sp. was isolated from the lymph node of a bottlenose dolphin found dead in the Poreč region. This was the first evidence of brucellosis in dolphins in the Adriatic Sea. The isolated sample was identified as Brucella ceti strain ST27, making this the first record of this strain in Europe, which may present a significant threat to human health.

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Evidence of Brucella strain ST27 in bottlenose dolphin ( Tursiops truncatus ) in Europe

Cited by 17 publications

References 25 publications

Brucella Genetic Variability in Wildlife Marine Mammals Populations Relates to Host Preference and Ocean Distribution

Brucella Genetic Variability in Wildlife Marine Mammals Populations Relates to Host Preference and Ocean Distribution

Th2 cytokine bias induced by silver nanoparticles in peripheral blood mononuclear cells of common bottlenose dolphins (Tursiops truncatus)

Brucellosis in marine mammals, with special emphasis on the Republic of Croatia

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