No abstract

Deoxynivalenol (DON) is related to reduced reproductive performance in males and females in several species. Children and adolescents showed a high risk of exposure to DON, however, no study has evaluated reproductive effects of DON at puberty. The present study aimed to evaluate the effects of DON at peripuberty on the testicles of pubertal rats. To achieve this, 10 Wistar rats (28 days old) were fed for 28 days with a DON-contaminated diet (9.4 mg/kg) or a control diet. After the experimental period, rats (56 days old) were euthanised and the following evaluations were performed in the testicles: dynamics of spermatogenesis, tubular morphometry, number of Sertoli cells and Leydig cells, analysis of caspase-3 expression, and the index of cell proliferation using the nucleolus organising regions (NOR) method. Ingestion of DON-contaminated diet induced a significant reduction in the number of Sertoli and Leydig cells and the number of seminiferous tubules in stage XIV. A significant increase in the number of NORs in seminiferous tubules in stage I-VI was observed in animals receiving the DON diet. No significant difference was noted in tubular morphometry or caspase-3 expression. Taken together, our results unravelled that the peripubertal exposure to DON compromised the testicular structure of pubertal rats, changing the dynamics of spermatogenesis.

BACKGROUND: Round fish is one of the most consumed fish in Brazil. Farmed fish feed is based mainly on grains, which are susceptible to contamination by mold and mycotoxins. Aspergillus spp., Penicillium spp. and Fusarium spp. are the major mycotoxins producers. The presence of potentially toxigenic fungi in the diet is a concern due to the possibility of cumulative toxins in fish tissues, becoming a risk to food safety. This study aims to assess the mycobiota of fish feed and the occurrence of aflatoxin residues in round fish tissues. Feed and fish samples were collected from fish farming and fish pay properties. Feed was submitted to mold counting and mold identification. The round fish liver and muscle were submitted to the detection and quantification of aflatoxins B 1 , B 2 , G 1 and G 2 by high-performance liquid chromatography. RESULTS: In evaluated feed, mold counts in the samples ranged from 2.0 to 4.7 log colony forming units g −1 and the major genera found were Penicillium (61.5%) and Aspergillus (34.6). Aflatoxin B 1 (AFB 1 ) was detected in 70% liver samples and 43.3% muscle samples, at levels up to 5.70 and 1.13 ∼g kg −1 , respectively. CONCLUSION: It is concluded that, although the levels were lower than those recommended by Brazilian legislation, round fish are being exposed to diets naturally contaminated by aflatoxins and are susceptible to toxins accumulation in tissues. Therefore, regulations regarding feed should consider limits for mold and aflatoxin contamination in fish edible tissues should be monitored in order to ensure consumers' safety.

AGRADECIMENTOSAgradeço a Deus primeiramente, pois, Ele é o sentido de tudo, obrigado pelas Graças concedidas, pela saúde, força e fé ao longo desta jornada.Agradeço a meus pais, mesmo às vezes não compreendendo não deixaram de dar seu apoio, em especial, ao meu namorado Alan que moveria montanhas para eu realizar todos meus sonhos e projetos, a minha grande amiga Bruna, por sempre me motivar a crescer como pessoa e nunca me deixar desistir quando surgem as adversidades. Vocês são mais que especiais, amo vocês! Agradeço a minha orientadora Andrezza pela oportunidade da realização do mestrado, por todo conhecimento que adquiri através da pesquisa, da companhia nos congressos e também nos city tour. Muito obrigada! Agradeço a Sílvia por toda ajuda ao longo do projeto e pela paciência, a Maria Fernanda pela amizade e pelos quilômetros rodados nas coletas e a Milena pela parceria no laboratório, nos congressos, viagens e cervejas! Sou muito grata a vocês! Agradeço a toda equipe do Laboratório Multiusuário de Microbiologia e Higiene Zootécnica pela convivência, apoio e companhia no café: