Antimicrobial resistance (AMR) is a serious problem for public and animal health, and also for the environment. Monitoring and reporting the occurrence of AMR determinants and bacteria with the potential to disseminate is a priority for health surveillance programs around the world and critical to the One Health concept. Wildlife is a reservoir of AMR, and human activities can strongly influence their resistome.The main goal of this work was to study the resistome of wild boar faecal microbiome, one of the most important game species in Europe using metagenomic and culturing approaches. The most abundant genes identified by the high-throughput qPCR array encode mobile genetic elements, including integrons, which can promote the dissemination of AMR determinants. A diverse set of genes (n = 62) conferring resistance to several classes of antibiotics (ARGs), some of them included in the WHO list of critically important antimicrobials were also detected. The most abundant ARGs confer resistance to tetracyclines and aminoglycosides. The phenotypic resistance of E. coli and Enterococcus spp. were also investigated, and together supported the metagenomic results.As the wild boar is an omnivorous animal, it can be a disseminator of AMR bacteria and ARGs to livestock, humans, and the environment. This study supports that wild boar can be a key sentinel species in ecosystems surveillance and should be included in National Action Plans to fight AMR, adopting a One Health approach.

There is limited research on the ingestion of microplastic particles (MPs) by fish from the southern part of the Mediterranean Sea. This study provides the occurrence of small MPs (≤3 μm) in the gastrointestinal tract and muscle of adult benthopelagic fish Serranus scriba (L.1758), caught along Tunisian coasts. MPs were extracted from selected tissues using a potassium hydroxide digestion method (KOH 10%) and then quantified, and their chemical structure was characterized through Raman microspectroscopy. The results highlighted that MPs were present in all samples. The average abundance of MPs per gram of fish tissue identified through successive filters of 3 μm, 1.2 μm, and 0.45 μm differed significantly among the sites. The properties of the MPs extracted indicated that polyethylene-vinyl-acetate (PEVA: 33.45%), high density polyethylene (HD-PE: 17.33%), and fragments were the most abundant plastic types and shape found, respectively. Among those, most MPs were found at a size class of 3–1.2 μm (∼60%), especially in the muscle, suggesting a high transfer of MPs into the human diet. Our field work also aimed to explore the effects observed in the gastrointestinal tract with a battery of biomarkers assessing oxidative stress and neurotoxicity. The preliminary results of this study showed the existence of a link between small MPs, sites, and their associated urban activities and induced oxidative stress. However, more detailed studies are required to evaluate the transfer of MPs into tissues and the potential impacts of this transfer on human health.

Fumonisins (FBs) are mycotoxins that are widely distributed in crops and feed, and ingestion of FBs -contaminated crops is harmful to animal health. Furthermore, it is unknown if Fumonisins B1 (FB1) can cause intestinal toxicity. To investigate FB1-induced intestinal toxicity, mice were treated with 0 or 5 mg/kg FB1 by gavage administration for 42 days. Histopathology indicated that FB1 exposure caused proliferation of intestinal epithelial cells, intestinal villi and epithelial layer shedding, intestinal gland atrophy, and necrosis. Notably, FB1 interfered with nuclear xenobiotic receptors (NXR) homeostasis by regulating the level of aryl hydrocarbon receptor (AHR), constitutive androstane receptor (CAR), pregnane X receptor (PXR) and downstream target genes (CYP450s). Moreover, abnormal expression of inflammatory cytokines (IL-1β, IL-2, IL-4, IL-10, and TNF-α) indicated the occurrence of inflammation. The present study provides new insights regarding the mechanism of FB1-induced intestinal toxicity through activating the NXR system and by triggering inflammatory responses in the intestinal tract in mice.

Dibutyl phthalate (DBP) is widely used as plasticizer and has been detected in the environment, posing a threat to animal health. However, the effects of DBP on agricultural microbiomes are not known. In this study, DBP levels in black soil were evaluated, and the impact of DBP contamination on the uptake and metabolism of sugars in microbes was assessed by glucose absorption tests, metaproteomics, metabolomics, enzyme activity assays and computational simulation analysis. The results indicated that DBP contamination accelerated glucose consumption and upregulated the expression of porins and periplasmic monosaccharide ATP-binding cassette (ABC) transporter solute-binding proteins (SBPs). DBP and its metabolic intermediates (carboxymuconate and butanol) may form a stable complex with sugar transporters and enhance the rigidity and stability of these proteins. Sugar metabolism resulting in the generation of ATP and reducing agent (NADPH), as well as the expression of some key enzymes (dehydrogenases) were also upregulated by DBP treatment. Moreover, a diverse bacterial community appears to utilize sugar, suggesting that there are widespread effects of DBP contamination on soil microbial ecosystems. The results of this study provide a theoretical basis for investigating the toxicological effects of DBP on microbes in black soil.

A key action of current aquatic environmental sciences is the determination of concentration-response assessments to quantitatively measure the risk of pollutants, and fish lethal tests are still a regulatory requirement for assessing the environmental risk of both new and existing substances in the aquatic compartment. However, animal health and welfare aspects, as well as the time and resources required to support fish lethal testing, stimulate research for alternative in vitro methods, and cell-based assays are considered as one such alternative. The first goal of the present study was to compile existing fish short-term toxicity and cell toxicity data of pesticides through a scientific literature search, and relate in vivo and in vitro results to identify sensitive cell models, mammalian-, fish- or arthropod-derived. Discovering cell models which are sensitive is of great importance, since the risk of false negatives, believed to be the main limitation of cell-based assays as an alternative to fish tests, may decrease. As to the second goal, this study also determined and compared cell toxicity results for 12 pesticides using rat cardiomyoblast H9c2(2–1) cells with the corresponding fish LC₅₀,₉₆ₕ (50% lethal concentration at 96 h of exposure) values collected in literature. On the whole, the in vivo/in vitro ratio was obtained for 50 pesticides belonging to 23 groups, and presented only 27% of positive results, thus confirming the low sensitivity of cell-based assays in relation to fish lethal data for pesticides. In general, cell-based assays still do not seem to be an alternative to the regulatory short-term fish assay for pesticides, making further studies necessary.

Diazinon is a common organophosphate pesticide widely used to control parasitic infections in agriculture. Excessive use of diazinon can have adverse effects on the environment and aquatic animal health. In the present study, the toxic effects of diazinon on the histology, antioxidant, innate immune and intestinal microbiota community composition of crucian carp (Carassius auratus gibelio) were investigated. The results showed that diazinon at the tested concentration (300 μg/L) induced gill and liver histopathological damages. Hepatic total superoxide dismutase (T-SOD), catalase (CAT), and glutathione S-transferase (GST) activities significantly decreased (P < 0.05) by 32.47%, 65.33% and 37.34%, respectively. However, the liver tissue malondialdehyde (MDA) content significantly (P < 0.05) increased by 138.83%. The 300 μg/L diazinon significantly (P < 0.05) downregulated the gene expression of TLR4, MyD88, NF-kB p100 and IL-8 but had no significant effect TNF-α (P = 0.8239). In addition, the results demonstrated that diazinon exposure could affect the intestinal microbiota composition and diversity. Taken together, the results of this study indicated that diazinon exposure can cause damage to crucian carp, induce histopathological damage in gill and liver tissues, oxidative stress in the liver, and innate immune disorders and alter intestinal microbiota composition and diversity.

Anthropogenic metal contamination can cause increased stress in exposed organisms, but it can be difficult to disentangle the anthropogenic influence from natural variation in environmental conditions. In the proximity of a closed lead (Pb)/zinc (Zn) mine in northern Sweden, the health effects of Pb exposure, essential element (calcium [Ca] and Zn) uptake, and prey availability and composition were estimated on pied flycatcher (Ficedula hypoleuca) nestlings, using hemoglobin (Hb) level as a proxy for health. Pb concentration in nestling blood range between 0.00034 and 2.21 μg/g (ww) and nestlings close to the mine had higher Pb concentrations and lower Hb, but contrary to our hypothesis, Hb was not directly related to Pb accumulation. Proportions of flying terrestrial and aquatic insects in available prey and availability of flying terrestrial insects were positively associated with nestling Hb, whereas the proportion of terrestrial ground living prey, the most common prey type, showed a negative association. This suggests that positive influence of certain prey, which does not have to be the most common in the surroundings, can counteract the negative effects from Pb contamination on bird health. Nestlings inhabiting sites adjacent to lakes had an advantage in terms of prey composition and availability of preferred prey, which resulted in higher Hb. As such, our results show that during moderate exposure to metals, variation in natural conditions, such as prey availability, can have great impact on organism health compared to Pb exposure.

Pollutant gases and particulate matters (PM) from livestock facilities can affect the health of animals and farm workers and lead to great social environmental risks. This paper presents a comprehensive study on the characteristics of ammonia (NH₃), nitrogen oxides (NOₓ), sulfur dioxide (SO₂) and PM (including PM₂.₅ and PM₁₀) in a 100,000-bird manure-belt layer house in suburb Beijing for three typical seasons of summer, autumn and winter. Indoor air was sampled at an exhaust fan of the mechanically ventilated commercial house. The monitored indoor concentrations of NH₃, NOₓ, SO₂, PM₂.₅ and PM₁₀ were 3.7–5.0 mg m⁻³, 17–58 μg m⁻³, 0–11 μg m⁻³, 100–149 μg m⁻³ and 354–828 μg m⁻³, respectively. The indoor NH₃ concentrations were largely influenced by the manure removal frequency. The NOₓ and SO₂ were mainly sourced from the ambient air, and the NOₓ was also partly sourced from manure decomposition in summer. The indoor PM₂.₅ and PM₁₀ were largely sourced from the ambient air and the indoor manure, respectively. The abundant indoor NH₃ caused significantly higher NH₄⁺ concentration in the indoor PM₁₀ (7.98 ± 9.04 μg m⁻³) than that in the ambient PM₁₀ (3.48 ± 3.52 μg m⁻³). Secondary inorganic ions (SO₄²⁻, NO₃⁻ and NH₄⁺) totally contributed 5.7% and 14.6% to the indoor and ambient PM₂.₅, respectively; they contributed 2.8% and 8.9% to the indoor and ambient PM₁₀, respectively. Organic carbon was the main component of the PM and accounted for 26.6% and 41.5% of the indoor PM₂.₅ and PM₁₀, respectively. Heavy metal elements (Zn, Cu and Cr) were likely transported from feed to manure and finally accumulated in the PM. Given the high emission potential, the air pollutants from animal production suggested potential risks for human health.

Particulate matter (PM) released from the processes of livestock production has a negative impact on the health of animals and workers. Herein, the concentration, major chemical components, morphology and microbiological compositions of particulate matter 2.5 (PM2.5, particles with aerodynamic diameter less than 2.5 μm) in a broiler breeding house were investigated. The results showed that the PM2.5 distribution in the chicken house was affected by the illumination, draught fans, chicken frame structure and activity of the chickens in the broiler breeding house. Component analysis showed that organic carbon (OC) accounted for the largest proportion, and followed by element carbon (EC), SO42−, NO3−, NH4+, Na+, K+ and Ca2+. Ultrastructural observations revealed that the shape of PM2.5 had a round, rectangular, chain-like and irregular shape. The concentration of endotoxin was approximately 0.3 EU/m3. Microbiological analysis showed that at the genus level, the pathogenic bacteria included Staphylococcus, Corynebacterium, Enterococcus, Parabacteroides, Escherichia and Megamonas. The abundant harmful fungi were Aspergillus, Scopulariopsis, Wallemia, and Fusarium. Through redundancy analysis (RDA) analysis, we determined that OC, EC, Na+, K+, and NH4+ had strong correlations with Brachybacterium, Brevibacterium, Corynebacterium, Escherichia, Scopulariopsis and Microascus. SO42− was closely related to Scopulariopsis and Salinicoccus. Salinicoccus was also strongly correlated with NO3−. Our results indicated that feed, faeces, and outside soot are contributed to the increase in PM2.5 concentration in the chicken house, while the sources of the dominant bacterial and fungi might be feed, faeces, suspended outside soil and cereal crops.