Review: Fish bile, a highly versatile biomarker for different environmental pollutants.

Ecotoxicological assessments encompass a broad spectrum of biochemical endpoints and ecological factors, allowing for comprehensive assessments concerning pollutant exposure levels and their effects on both fish populations and surrounding ecosystems. While these evaluations offer invaluable insights into the overall health and dynamics of aquatic environments, they often provide an integrated perspective, making it challenging to pinpoint the precise sources and individual-level responses to environmental contaminants. In contrast, biliary pollutant excretion assessments represent a focused approach aimed at understanding how fish at the individual level respond to environmental stressors. In this sense, the analysis of pollutant profiles in fish bile not only serves as a valuable exposure indicator, but also provides critical information concerning the uptake, metabolism, and elimination of specific contaminants. Therefore, by investigating unique and dynamic fish responses to various pollutants, biliary assessments can contribute significantly to the refinement of ecotoxicological studies. This review aims to discuss the multifaceted utility of bile as a potent biomarker for various environmental pollutants in fish in targeted monitoring strategies, such as polycyclic aromatic hydrocarbons, metals, pesticides, pharmaceuticals, estrogenic compounds, resin acids, hepatotoxins and per- and polyfluorinated substances. The main caveats of this type of assessment are also discussed, as well as future directions of fish bile studies.

Ecotoxicology applied to conservation: Potential negative metal and metalloid contamination effects on the homeostatic balance of the critically endangered Brazilian guitarfish, Pseudobatos horkelii (Elasmobranchii: Rhinobatidae).

Metal contamination poses a significant threat to elasmobranchs, underscoring the need for targeted conservation approaches. The critically endangered Brazilian guitarfish, Pseudobatos horkelii, confronts an array of challenges, notably overexploitation, putting its survival at risk. Our study investigated the potential toxicity arising from arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) contamination across various adult guitarfish tissues from southeastern Brazil. Serological stress indicators, nutritional metabolites, and creatinine, an organ function marker, were also assessed, and Selenium (Se) levels were also investigated for possible protective effects. Our investigation unveiled significant correlations between metal concentrations and the determined physiological markers, shedding light on potential adverse effects. Remarkably, six correlations were indicative of how Hg and Pb negatively impact hepatic metabolite assimilation, while As was shown to influence renal phosphorus dynamics, Cd to affect rectal gland phosphorus regulation, and Pb to influence creatinine production in muscle tissue. Furthermore, Se demonstrated protective properties against Cd, Hg, and Pb, suggesting a role in alleviating the toxicity of these elements. Despite probable protective Se influences, the detected elemental interactions still suggest potential for organ impairment. These findings gain heightened significance within the context of the cumulative stressors faced by the Brazilian guitarfish, with metal contamination exhibiting the capacity to erode this species resilience against both anthropogenic and environmental pressures, thereby disrupting systemic equilibrium and jeopardizing wild populations. By investigating the intricate balance between metal accumulation and physiological consequences, our study contributes with crucial insights into potential conservation strategy formulations towards pollution for this critically endangered elasmobranch species.

A Novel One Health Approach concerning Yeast Present in the Oral Microbiome of the Endangered Rio Skate (Rioraja agassizii) from Southeastern Brazil.

The current climate change scenario caused by anthropogenic activities has resulted in novel environmental pressures, increasing the occurrence and severity of fungal infections in the marine environment. Research on fungi in several taxonomic groups is widespread although not the case for elasmobranchs (sharks and rays). In this context, the aim of the present study was to screen the oral fungal microbiota present in artisanally captured Rioraja agassizii, a batoid that, although endangered, is highly fished and consumed worldwide. Oropharyngeal samples were obtained by swabbing and the samples were investigated using morphological and phenotypic methods by streaking on Sabouraud Dextrose Agar (SDA) and subculturing onto CHROMagar Candida (BD Difco) and CHROMagar Candida Plus (CHROMagarTM), as well as molecular techniques by amplification of the ITS1-5.8S-ITS2 ribosomal DNA region and a MALDI-TOF MS assessment. The findings indicated the presence of Candida parapsilosis (seven isolates), Candida duobushaemulonii (one isolate) and Rhodotorula mucilaginosa (three isolates), several of these reported for the first time in Rioraja agassizii. In addition, a 100% agreement between the MALDI-TOF results and partial ITS region sequencing was noted, demonstrating that the MALDI-TOF MS is a rapid and effective alternative for yeast identification in Rioraja agassizii isolates and potentially in other elasmobranch species. These findings highlight the need for further research to determine the potential impact on elasmobranch health, ecology, and commercial fisheries. Furthermore, this research is paramount in a One Health framework and may be employed to predict elasmobranch responses to an evolving ocean, keep healthy populations in check, monitor species, and assess the public health consequences of consuming these species.

Interactions between mercury and environmental factors: A chemometric assessment in seafood from an eutrophic estuary in southeastern Brazil.

Guanabara Bay (GB) is an estuary in Brazil, constantly the target of pollutants, such as mercury (Hg). Thus, our study aimed to evaluate (i) total mercury (THg) content in shrimp and squid species from GB; (ii) associate THg content to contamination in swimming crabs; (iii) explore potential differences between species, and size; (iv) correlate abiotic water data to the determined THg contents; (v) verify if Hg concentrations are below acceptable limits. Swimming crabs showed greater Hg contamination compared to other species. For shrimp only biometric variables are related to Hg, while for squid, only abiotic. Only squids did not show a correlation between Hg and animal size. Finally, the detected Hg values are below the tolerable limits established by legislations. Our results indicate that the dynamics of Hg contamination differs between groups and that further studies are needed to elucidate the mechanisms that affect bioaccumulation in different species.

Acesso ao Saneamento básico e Incidência de Cólera: uma análise quantitativa entre 2010 e 2015 / Access to basic and analytical sanitation of cholera: a quantitative analysis between 2010 and 2015

RESUMO As condições de saneamento básico são um dos principais determinantes nos índices de agravos à saúde humana, principalmente no tocante a doenças infectocontagiosas por veiculação hídrica. Dentre todas, destacamos neste trabalho a cólera: doença entérica causada pelas cepas toxigênicas do Vibrio cholerae (sorogrupos O1 e O139), que é caracterizada por um quadro de acentuada diarreia. O objetivo deste trabalho, por meio de levantamento de dados mundiais de Incidência de Cólera (IC) e percentual populacional de Acesso ao Saneamento (AS), é quantificar, evidenciar e discutir a relação entre esses dois indicadores no período de 2010 a 2015, assim como apontar outros possíveis fatores magnificantes de vulnerabilidade socioambiental para a patologia. No período analisado, foram registrados 1.575.168 casos da doença, com as maiores incidências na região do subcontinente áfrico-asiático e em países isolados nos demais continentes, como, por exemplo, Haiti (América) e Papua Nova Guiné (Oceania), que também apresentaram sérios problemas de acessibilidade a serviços de saneamento. Desta forma, apesar de sugerirmos a análise de outros fatores socioambientais, as condições de saneamento revelaram-se como um determinante expressivo para a incidência da cólera em todas as regiões do mundo.

ABSTRACT Health conditions are among the main factors leading to human health damages, particularly concerning infectious diseases by water transmission. Among those cholera is highlighted in this work: the virus infection of Vibrio cholerae toxicity (serogroups O1 and O139), which is characterized by marked diarrhea. Using incidence data on cholera (CI) and the population percentage of Access to Sanitation (AS) collected throughout the world, the objective of this work is to quantify, highlight and discuss relationship between those two indicators over the period from 2010 to 2015, besides pointing out other possible magnifying factors of socioenvironmental vulnerability to this pathology. Over that period, 1,575,168 cases of the illness were analyzed, showing more frequent occurrences in the region of the African-Asian subcontinent and isolated countries in the other continents, such as Haiti (America) and Papua New Guinea (Oceania), which also presented serious problems regarding the access to sanitation services. Thus, although we suggest other socioenvironmental factors to also be analyzed sanitation conditions proved to be an expressive determinant for the incidence of cholera in all regions worldwide.