Correction to: Organochlorine Chemical Residues in Northern Cardinal (Cardinalis cardinalis) Eggs from Greater Washington, DC USA.

The original version of this article contained a mistake. Author name in the text citation and reference in section should be Maldonado et al (2016), it was incorrectly spelled as Maldinado et al (2015).

Organochlorine Chemical Residues in Northern Cardinal (Cardinalis cardinalis) Eggs from Greater Washington, DC USA.

Northern Cardinal eggs from six neighborhoods near Washington DC were analyzed for organochlorine pesticides and PCBs. All compounds were detected more frequently and at higher concentrations in more heavily urbanized neighborhoods. DDT (mostly as p,p'-DDE) was detected in all neighborhoods. p,p'-DDT was typically 0.5‒16 ng/g (ww) in most suburban neighborhoods but was not detected (< 0.1 ng/g) in more rural areas; however, p,p'-DDT was 127‒1130 ng/g in eggs from two suburban Maryland nests and comprised 65.7% of total p,p'-DDT isomers in the most contaminated sample, indicating recent exposure to un-weathered DDT. Total chlordane (sum of 5 compounds) was 2‒70 ng/g; concentrations were greatest in older suburban neighborhoods. Total PCB (sum of detected congeners) was < 5‒21 ng/g. Congener patterns were similar in all neighborhoods and resembled those typical of weathered mixtures. Results indicate that wildlife remains exposed to low concentrations of legacy contaminants in suburban neighborhoods and that cardinal eggs can be used to monitor localized contamination.

Thyroid histopathology assessments for the amphibian metamorphosis assay to detect thyroid-active substances.

In support of an Organization for Economic Cooperation and Development (OECD) Amphibian Metamorphosis Assay (AMA) Test Guideline for the detection of substances that interact with the hypothalamic-pituitary-thyroid axis, a document was developed that provides a standardized approach for evaluating the histology/histopathology of thyroid glands in metamorphosing Xenopus laevis tadpoles. Here, a consolidated description of histology evaluation practices, core diagnostic criteria and severity grading schemes for the AMA, an atlas of the normal architecture of amphibian thyroid glands over the course of metamorphosis, and the core diagnostic criteria with examples of severity grades is provided. Core diagnostic criteria include thyroid gland hypertrophy/atrophy, follicular cell hypertrophy, and follicular cell hyperplasia. The severity grading scheme is semiquantitative and employs a four-grade approach describing ranges of variation within assigned ordinal classes: not remarkable, mild, moderate, and severe. The purpose of this severity grading approach is to provide an efficient, semi-objective tool for comparing changes (compound-related effects) among animals, treatment groups, and studies. Proposed descriptions of lesions for scoring the four core criteria are also given.

Unidentified Plasmodium species in Australian black swans (Cygnus atratus) hatched and raised in North America.

A pair of Australian black swans (Cygnus atratus) with origins in Wakefield, Virginia, USA, was admitted to the quarantine area at the Baltimore Zoo for general health assessments before housing in the collections. During the quarantine period, no clinical signs of disease were manifest; however, upon examination of a blood smear, intraerythrocytic parasites were detected and initially determined to be Haemoproteus species. Diagnostic polymerase chain reaction (PCR) and sequencing results, however, indicated that the parasites were within the genus Plasmodium. Subclinical infections with Plasmodium species in birds may affect collection management, and transmission from refractory hosts to susceptible hosts should be considered when multispecies exhibits are used. In addition, changes in the dynamics of host-vector-parasite interactions might have significant impacts on wild or domesticated populations of birds.

Intersex in Japanese medaka (Oryzias latipes) used as negative controls in toxicologic bioassays: a review of 54 cases from 41 studies.

Histologic assessment of the gonads to detect intersex has become a valuable end point in reproductive toxicologic testing for fish, and many studies have solidly linked intersex with exposure to endocrine active substances (EAS). An assumption in such studies is that spontaneous intersex does not occur in control fish. Using historical data derived from toxicologic tests with Japanese medaka (Oryzias latipes), we report a retrospective study in which we identified 54 individual instances of intersex (testicular oocytes or ovarian testicular tissue) in control medaka from 15 of 41 selected toxicologic studies. These studies, comprised of previously unpublished data, had been conducted at three geographically distant laboratories, each of which utilized unique water sources, employed somewhat different culture protocols, and maintained distinct medaka breeding colonies. During our histologic examinations, we also identified three germ cell neoplasms that had been inadvertently diagnosed as intersex. In the present report, we review potential causes of intersex, discuss possible reasons why spontaneous intersex has rarely been reported, and propose suggestions for the judicious interpretation of intersex results in medaka studies involving EAS.

Preliminary results of an anticircumsporozoite DNA vaccine trial for protection against avian malaria in captive African black-footed penguins (Spheniscus demersus).

Captive juvenile African black-footed penguins (Spheniscus demersus) housed in an outdoor enclosure at the Baltimore Zoo have an average 50% mortality from avian malarial (Plasmodium sp.) infection each year without intense monitoring for disease and chemotherapeutic intervention. During the 1996 malaria transmission season, the safety and efficacy of an anti-circumsporozoite (CSP) DNA vaccine encoding the Plasmodium gallinaceum CSP protein against P. relictum were studied. The goal was to reduce clinical disease and death without initiating sterile immunity after release into an area with stable, endemic avian malaria. The birds were monitored for adverse clinical signs associated with vaccination, the stimulation of an anti-CSP antibody response, and protection afforded by the vaccine. The presence of P. relictum in trapped culicine mosquitoes within the penguin enclosure was monitored to assess parasite pressure. Among the vaccinated penguins, the parasitemia rate dropped from approximately 50% to approximately 17% despite intense parasite pressure, as determined by mosquito infection rate. During the year of the vaccine trial, no mortalities due to malaria occurred and no undesirable vaccination side effects occurred. This is the first trial of an antimalarial vaccine in a captive penguin colony.

Measuring the effects of an ever-changing environment on malaria control.

The effectiveness of malaria control measures depends not only on the potency of the control measures themselves but also upon the influence of variables associated with the environment. Environmental variables have the capacity either to enhance or to impair the desired outcome. An optimal outcome in the field, which is ultimately the real goal of vaccine research, will result from prior knowledge of both the potency of the control measures and the role of environmental variables. Here we describe both the potential effectiveness of control measures and the problems associated with testing in an area of endemicity. We placed canaries with different immunologic backgrounds (e.g., naïve to malaria infection, vaccinated naïve, and immune) directly into an area where avian malaria, Plasmodium relictum, is endemic. In our study setting, canaries that are naïve to malaria infection routinely suffer approximately 50% mortality during their first period of exposure to the disease. In comparison, birds vaccinated and boosted with a DNA vaccine plasmid encoding the circumsporozoite protein of P. relictum exhibited a moderate degree of protection against natural infection (P < 0.01). In the second year we followed the fate of all surviving birds with no further manipulation. The vaccinated birds from the first year were no longer statistically distinguishable for protection against malaria from cages of naïve birds. During this period, 36% of vaccinated birds died of malaria. We postulate that the vaccine-induced protective immune responses prevented the acquisition of natural immunity similar to that concurrently acquired by birds in a neighboring cage. These results indicate that dominant environmental parameters associated with malaria deaths can be addressed before their application to a less malleable human system.

Plasmodium Juxtanucleare associated with mortality in black-footed penguins (Spheniscus demersus) admitted to a rehabilitation center.

Five black-footed penguins (Spheniscus demersus) admitted to the Southern African Foundation for the Conservation of Coastal Birds, in Cape Town, South Africa, died from malaria infection. Evidence for malaria as the cause of death included antemortem clinical signs, parasitemia, splenomegaly, pulmonary edema, and the presence of histologically visible schizonts in the reticuloendothelial system. A portion of the malarial small subunit ribosomal ribonucleic acid gene was detected by polymerase chain reaction from postmortem blood samples from all the birds. A species-specific variable region of this gene was compared with the same region on genes from other known avian malarial organisms, establishing that Plasmodium juxtanucleare was involved.