Detection of phthalate esters and targeted metabolome analysis in Franciscana dolphin (Pontoporia blainvillei) blubber in the coast of Santa Catarina, southern Brazil.

The concerning of plastic pollution in different ecosystems has been worsened by the widespread presence. Phthalate esters (PAEs), plasticizers found in everyday products, can migrate into the environment, especially into the oceans. Researches on their effects on cetaceans are still rare. Metabolomics helps assess perturbations induced by exposure to PAEs, which act as persistent endocrine disruptors. Four PAEs (dimethyl phthalate - DMP, diethyl phthalate - DEP, dibutyl phthalate - DBP, and di(2-ethylhexyl phthalate - DEHP) were analyzed, along with cholesterol and fatty acid profiles of P. blainvillei's blubber samples collected in southern Brazil. The study reveals pervasive contamination by PAEs - especially DEHP, present in all samples - with positive correlations between DEP content and animal size and weight, as well as between the DEHP amount and the C17:1 fatty acid. These findings will be relevant to conservation efforts aimed at this threatened species and overall marine ecosystems.

Biochemical and molecular biomarkers and their association with anthropogenic chemicals in wintering Manx shearwaters (Puffinus puffinus).

Anthropogenic pollution poses a threat to marine conservation by causing chronic toxic effects. Seabirds have contact throughout their lives with pollutants like plastic, metals, polychlorinated biphenyls (PCBs), and organochlorine pesticides such as hexachlorocyclohexanes (HCHs). We assessed 155 Manx shearwaters (Puffinus puffinus) stranded along the Brazilian coast, analyzing associations between organic pollutants, plastic ingestion, biomarkers (transcript levels of aryl hydrocarbon receptor, cytochrome P450-1A-5 [CYP1A5], UDP-glucuronosyl-transferase [UGT1], estrogen receptor alpha-1 [ESR1], and heat shock protein-70 genes) and enzymes activity (ethoxy-resorufin O-deethylase and glutathione S-transferase [GST]). Plastic debris was found in 29 % of the birds. The transcription of UGT1 and CYP1A5 was significantly associated with hexachlorobenzene (HCB) and PCBs levels. ESR1 was associated with HCB and Mirex, and GST was associated with Drins and Mirex. While organic pollutants affected shearwaters more than plastic ingestion, reducing plastic availability remains relevant as xenobiotics are also potentially adsorbed onto plastics.

PHTHALATE ESTERS (PLASTICIZERS) IN THE UROPYGIAL GLAND AND THEIR RELATIONSHIP TO PLASTICS INGESTION IN SEABIRDS ALONG THE COAST OF ESPÍRITO SANTO, EASTERN BRAZIL.

Plastic ingestion is a problem for seabirds worldwide. In addition to direct health effects such as obstruction or perforation of the gastrointestinal tract, plastic ingestion can also lead to indirect health effects through the release of chemicals that may be absorbed and cause systemic and chronic toxicity. Among chemicals that can be released by plastics are phthalate esters, a group of chemicals widely used as plasticizers or additives to change the physical characteristics of plastics. In this study, three phthalate esters, dimethyl phthalate (DMP), dibuthyl phthalate (DBP), and diethylhexyl phthalate (DEHP), were quantified in the uropygial gland of 48 seabirds from 16 species collected ashore in a tropical region, the coast of Espírito Santo, Eastern Brazil. Including trace levels, DMP was detected in 16 birds (33%) from 10 species, with an average concentration of 0.014 ± 0.005 ng/µl (mean ± SD for individuals with concentrations above the practical level of detection of 0.01 ng/µl). DBP was detected in 15 birds (31%) from 11 species, with an average concentration of 0.049 ± 0.032 ng/µl. DEHP was detected in 21 birds (44%) from 11 species, with an average concentration of 0.115 ± 0.105 ng/µl. DMP concentration in the uropygial gland was positively associated with the presence, number, and mass of plastic items in the upper digestive tract. However, no such relationship was noted for DBP nor DEHP, suggesting the concentration of phthalate compounds in the uropygial gland might not always serve as a reliable proxy for plastic ingestion. In spite of relatively high frequencies of detection, the low concentrations of phthalates detected in this study suggest levels of exposure below known toxicity thresholds. Further studies on the potential adverse effects of phthalate exposure in seabirds are necessary, especially on the reproductive development of embryos and chicks.

Identification and antimicrobial susceptibility of milk pathogen isolated from dairy production systems.

Livestock has been recognized as a reservoir of antibiotic-resistant bacteria. Prevalence of resistance has been associated with herd size and intensification of animal production systems. Brazil is one of the emergent hotspots of bacterial resistance, which is also associated with animal husbandry. This study aimed to evaluate the resistance profile of pathogens that cause subclinical mastitis and the relationship between resistance status at farm level and different production systems. Milk samples from cows diagnosed with subclinical mastitis were collected from farms that adopt different husbandry systems with different production intensities, i.e., agroecological, low input, high input, Free-Stall and Compost-bedded pack barn. Etiological agents were isolated and microbiologically identified, and antibiotic susceptibility testing was conducted, using the disk diffusion method. The main isolated agents were Streptococcus spp. (n = 54, 30.5 %) and coagulase-positive Staphylococcus (CPS) (n = 54; 30.5 %). The recovered isolates displayed high antibiotic resistance against Sulfamethazine (80.2 %), Gentamicin (29.37 %), Penicillin (29.37 %), Oxacillin (28.82 %) and Ampicillin (26 %). Multidrug resistance was found for all agents and in all farming systems (39.54 %). Neither production systems (p = 0.26) nor farming systems (p = 0.24) significantly affected the resistance rates of samples. Therefore, intensive production systems may not be a root cause of increased rates of antimicrobial resistance in the milk production chain, suggesting that other environmental factors should be investigated. It is noteworthy that high levels of multidrug resistance were even found in bacteria earlier considered as minor pathogens. This development can be taken as a warning that environmental bacteria are potential transmitters of resistance genes to the environment.