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- Bioaccumulation and elimination kinetics of metals and polycyclic aromatic hydrocarbons in Hermetia illucens larvae: Implications for risk mitigation of selected contaminants in insect farmingPublication . Mostafaie, Amid; Silva, Patricia V.; Prodana, Marija; Silva, Ana Rita R.; Pinto, José N.; Duarte, Regina M.B.O.; Alvito, Paula; Coelho, Inês; Rego, Andreia; Lopes, Iva G.; Brooks, Bryan W.; Loureiro, Susana; Cardoso, Diogo N.Rapidly expanding insect farming industries worldwide are raising concerns about introducing contaminants into food chains. One of the dominant species in this new bioindustry, the black soldier fly (Hermetia illucens), offers diverse benefits ranging from protein production to waste management, biofuel, and pharmaceutical applications. Recent studies have highlighted the ability of insects to accumulate metals; however, knowledge of their ability to eliminate contaminants is needed. Similarly, information regarding the accumulation of polycyclic aromatic hydrocarbons (PAHs) is lacking. This study aimed to understand how H. illucens larvae accumulate and eliminate metals and PAHs from contaminated substrates. We performed two-phase bioaccumulation experiments followed by toxicokinetic modelling to estimate uptake and elimination rate constants and half-lives in H. illucens. During the uptake phase, insects were exposed for five days to contaminated substrates at EU maximum feed concentrations: 2 mg kg−1 for As and Cd, 10 mg kg−1 for Pb, and 12.5 μg kg−1 for each of four PAHs (benzo[a]pyrene, benz[a]anthracene, benzo[b]fluoranthene, chrysene). In the second phase, insects were exposed to non-contaminated substrates for five days to evaluate elimination. Results showed metal accumulation with kinetic bioaccumulation factors of 4.26, 1.16, and 1.31 for Cd, As, and Pb, respectively. A one-day depuration reduced As and Pb below regulatory thresholds; Cd required three days. Minimal to no accumulation was observed for B[a]P and B[b]F, with higher uptake for B[a]A. PAH half-lives were under one day. These findings, from controlled experiments with limited contaminants, support incorporating a depuration phase for risk mitigation in H. illucens waste-to-protein systems.
- Challenges of the Application of In Vitro Digestion for Nanomaterials Safety AssessmentPublication . Vital, Nádia; Gramacho, Ana Catarina; Silva, Mafalda; Cardoso, Maria; Alvito, Paula; Kranendonk, Michel; Silva, Maria Joao; Louro, HenriquetaConsidering the increase in the production and use of nanomaterials (NM) in food/feed and food contact materials, novel strategies for efficient and sustainable hazard characterization, especially in the early stages of NM development, have been proposed. Some of these strategies encompass the utilization of in vitro simulated digestion prior to cytotoxic and genotoxic assessment. This entails exposing NM to fluids that replicate the three successive phases of digestion: oral, gastric, and intestinal. Subsequently, the resulting digestion products are added to models of intestinal cells to conduct toxicological assays, analyzing multiple endpoints. Nonetheless, exposure of intestinal cells to the digested products may induce cytotoxicity effects, thereby posing a challenge to this strategy. The aim of this work was to describe the challenges encountered with the in vitro digestion INFOGEST 2.0 protocol when using the digestion product in toxicological studies of NM, and the adjustments implemented to enable its use in subsequent in vitro biological assays with intestinal cell models. The adaptation of the digestion fluids, in particular the reduction of the final bile concentration, resulted in a reduced toxic impact of digestion products.
- Ciguatera toxins, a potential health risk emerging in Europe: overview of progress and challengesPublication . Alvito, Paula; Gago-Martínez, Ana; AlvitoCiguatera Poisoning (CP) is considered an emerging risk of concern in several places worldwide. The risk of CP in Europe is currently being investigated, and important advantages have been achieved under two EuroCigua projects, which allowed the characterization of Caribbean Ciguatoxins as the main responsible for the contamination in the European Coastal areas investigated. Important challenges and limitations, particularly the ones related to the lack of reference materials and of relevant samples that enable to associate the contaminated fish consumption with human intoxication, are the most critical aspects hindering the progress from both analytical and toxicological perspectives. This review aims to provide an update on the most recent advances in CP in Europe on the source of the toxins involved in contamination, their toxicology and pharmacology, and their detection and characterization in order to contribute to envisioning the toxic mechanism of CP in humans.
- Genomic Analysis of Antibiotic Resistance and Virulence Profiles in Escherichia coli Linked to Sternal Bursitis in Chickens: A One Health PerspectivePublication . Ribeiro, Jessica; Silva, Vanessa; Freitas, Catarina; Pinto, Pedro; Vieira-Pinto, Madalena; Batista, Rita; Nunes, Alexandra; Gomes, João Paulo; Pereira, José Eduardo; Igrejas, Gilberto; Barros, Lillian; Heleno, Sandrina A.; Reis, Filipa S.; Poeta, PatríciaAbstract: Sternal bursitis is an underexplored lesion in poultry, often overlooked in microbiological diagnostics. In this study, we characterized 36 Escherichia coli isolates recovered from sternal bursitis in broiler chickens, combining phenotypic antimicrobial susceptibility testing, PCRbased screening, and whole genome sequencing (WGS). The genetic analysis revealed a diverse population spanning 15 sequence types, including ST155, ST201, and ST58. Resistance to tetracycline and ciprofloxacin was common, and several isolates carried genes encoding β-lactamases, including blaTEM-1B. Chromosomal mutations associated with quinolone and fosfomycin resistance (e.g., gyrA p.S83L, glpT_E448K) were also identified. WGS revealed a high number of virulence-associated genes per isolate (58–96), notably those linked to adhesion (fim, ecp clusters), secretion systems (T6SS), and iron acquisition (ent, fep, fes), suggesting strong pathogenic potential. Many isolates harbored virulence markers typical of ExPEC/APEC, such as iss, ompT, and traT, even in the absence of multidrug resistance. Our findings suggest that E. coli from sternal bursitis may act as reservoirs of resistance and virulence traits relevant to animal and public health. This highlights the need for including such lesions in genomic surveillance programs and reinforces the importance of integrated One Health approaches.