Clinicoimmunopathologic findings in Atlantic bottlenose dolphins Tursiops truncatus with positive Chlamydiaceae antibody titers

Abstract

Sera from free-ranging Atlantic bottlenose dolphins Tursiops truncatus inhabiting the Indian River Lagoon (IRL), Florida, and coastal waters of Charleston (CHS), South Carolina, USA, were tested for antibodies to Chlamydiaceae as part of a multidisciplinary study of individual and population health. A suite of clinicoimmunopathologic variables was evaluated in Chlamydiaceae-seropositive dolphins (n = 43) and seronegative healthy dolphins (n = 83). Fibrinogen, lactate dehydrogenase, amylase, and absolute numbers of neutrophils, lymphocytes, and basophils were significantly higher, and serum bicarbonate, total alpha globulin, and alpha-2 globulin were significantly lower in dolphins with positive Chlamydiaceae titers compared with seronegative healthy dolphins. Several differences in markers of innate and adaptive immunity were also found. Concanavalin A-induced T lymphocyte proliferation, lipopolysaccharide-induced B lymphocyte proliferation, and granulocytic phagocytosis were significantly lower, and absolute numbers of mature CD 21 B lymphocytes, natural killer cell activity and lysozyme concentration were significantly higher in dolphins with positive Chlamydiaceae antibody titers compared to seronegative healthy dolphins. Additionally, dolphins with positive Chlamydiaceae antibody titers had significant increases in ELISA antibody titers to Erysipelothrix rhusiopathiae. These data suggest that Chlamydiaceae infection may produce subclinical clinicoimmunopathologic perturbations that impact health. Any potential subclinical health impacts are important for the IRL and CHS dolphin populations, as past studies have indicated that both dolphin populations are affected by other complex infectious and neoplastic diseases, often associated with immunologic perturbations and anthropogenic contaminants.

Health and Environmental Risk Assessment Project for bottlenose dolphins Tursiops truncatus from the southeastern USA. I. Infectious diseases

“…In this study, the seroprevalence of C. psittaci was 85 and 84% in dolphins from the IRL and CHS, respectively. Our follow-up study demonstrated that dolphins with a seropositive Chlamydiaceae antibody titer had several immunologic irregularities when compared to healthy dolphins (Bossart et al 2014). Dolphins with positive Chlamydiaceae titers had significantly lower Con A-induced T lymphocyte proliferation, LPSinduced B lymphocyte proliferation, and granulocytic phagocytosis when compared to healthy dolphins.…”

“…Both E. rhusiopathiae and C. psittaci infections have been described in marine birds (Hubálek 2004). We speculated that the high seroprevalence of antibody to both Chlamydiaceae and E. rhusiopathiae in HERA dolphins might be caused by shedding of the agents among local bird reservoir populations which in turn may serve as potential sources of both chlamydial and E. rhusiopathiae infection (Bossart et al 2014). The data suggest inapparent Chlamydiaceae infection impacts immunologic status which could make infected IRL and CHS dolphins susceptible to other diseases.…”

“…Dolphins with positive Chlamydiaceae titers also had significant increases in Erysipelothrix rhusiopathiae titers (Bossart et al 2014). E. rhusiopathiae is a common marine microorganism that may cause disease in cetaceans (Bossart & Eimstad 1988).…”

Evidence of sewage-driven eutrophication and harmful algal blooms in Florida's Indian River Lagoon

“…Groundwaters contaminated by OSTDS have impacted a wide variety of other urbanized estuaries and coastal waters, including Bermuda (Lapointe and O'Connell, 1989;McGlathery, 1995), the Florida Keys (Lapointe et al, 1990;Tomasko and Lapointe, 1991;Lapointe et al, 1994), Cape Cod, MA (Valiela et al, 1992;Weiskel and Howes, 1992;Valiela et al, 1997), Outer Banks, North Carolina (Mallin, 2013), Chesapeake Bay (Reay, 2004), and Puerto Rico (Olsen et al, 2010). In addition, bacterial contamination of groundwaters and surface waters has been associated with unsuitable soil characteristics and high densities of OSTDS on the IRL watersheds (Lapointe and Krupa, 1995a,b;Belanger et al, 2007;Lapointe et al, 2012) and is considered a primary source of bacterial contamination associated with immunologic perturbations in populations of bottlenose dolphins, Tursiops truncatus Montagu, in the IRL (Schaefer et al, 2009;Bossart et al, 2014). Schaefer et al (2011) found a positive correlation between the number of IRL bottlenose dolphins colonized by Escherichia coli and the number of septic tanks in the area they lived; with the highest number of both being in the northern segments of the IRL.…”

Phenotyping and comparing the immune cell populations of free-ranging Atlantic bottlenose dolphins (Tursiops truncatus) and dolphins under human care

“…For example, dolphins infected with lobomycosis, a mycotic skin disease, displayed a suppressed immune system compared to dolphins without a visible infection [19]. Dolphins with antibody titers positive to bacterial infection, Chlamydiaceae , showed changes in their innate and adaptive immunological parameters [20]. Dolphins with positive morbilliviral antibody titers had decreased T cell proliferation and absolute number, suggestive of adverse changes in their immune system [21].…”