Andrezza Maria Fernandes

This review analyzes the occurrence and co-exposure of aflatoxins and fumonisins in conventional and organic corn, and compares the vulnerability to contamination of both. The risks of fungal contamination in corn are real, mainly by the genera Aspergillus and Fusarium, producers of aflatoxins and fumonisins, respectively. Aflatoxins, especially AFB₁, are related to a high incidence of liver cancer, and the International Agency Research of Cancer (IARC) classified them in group 1A 'carcinogenic to humans'. The occurrence in conventional corn is reported in many countries, including at higher levels than those established by legislation. IARC classified fumonisins in group 2B 'possibly carcinogenic to humans' due to their link with incidence of esophageal cancer. However, comparing corn and organic and conventional by-products from different regions, different results are observed. The co-occurrence of both mycotoxins is a worldwide problem; nevertheless, there is little data on the comparison of the co-exposure of these mycotoxins in corn and derivatives between both systems. It was found that the agricultural system is not a decisive factor in the final contamination, indicating the necessity of effective strategies to reduce contamination and co-exposure at levels that do not pose health risks.

The constant intensification of aquaculture has considerable increased the stress levels of farmed fish and, consequently, the number and intensity of diseases outbreaks. Thus, studies on fish immune response, especially regarding the interaction of fish leukocytes with potential pathogens and xenobiotics are of great importance in order to develop new prophylactic and curative strategies. We isolated leukocytes from the head kidney of Astyanax lacustris—an important Neotropical fish species for aquaculture and a potential model for Neotropical aquaculture research—using a Percoll centrifugation protocol. The isolated leukocytes were incubated with lipopolysaccharide (LPS), and the expression of genes IL-1β, IL-8, LysC, and LysG were measured. We assessed the phagocytotic activity of leukocytes using Congo red-dyed yeast, a novel and cost-effective protocol that has been developed in this study. The isolated leukocytes responded to LPS induction, exhibiting strong IL-1β and IL-8 upregulation, two of the most important pro-inflammatory interleukins for vertebrates immune reponse. The optimal concentration of yeast for the phagocytic assay was 106 cells mL-1, resulting in acceptable phagocytic capacity (PC) but without excess of yeasts during the counting process, ensuring a high precision and accuracy of the method. To the best of our knowledge, the present study is the first to investigate the in vitro gene expression and phagocytic activity of leukocytes isolated from A. lacustris. Our findings will serve as a reference for future studies on the immunology and toxicology of Neotropical fish.

The aim of this study was to evaluate the occurrence of aflatoxins in feed and tilapia tissues from fish farms in Brazil. Samples of feed, liver, and muscle from different properties in Brazil were evaluated for aflatoxins B₁, B₂, G₁, and G₂. AFG₁ and AFB₁ were found in feed and liver samples. AFB₁ was found in 19.05% of muscle samples. Despite the values below the limits in feed and the low levels in tissues, results revealed exposure to aflatoxins. Therefore, aflatoxin limits in regulations regarding aquaculture are needed, as well as monitoring of fish feed contamination and aflatoxin residues in edible fish tissues.

In recent years, annual cases of gastroenteritis have been reported in the world at high rates, suggesting an association with the consumption of shellfish with enteric viruses in their tissues. Anthropic activities are considered a source of environmental pollution and the main responsible for contamination by pathogenic microorganisms in aquatic environments. The objective of this study was to evaluate, by RT-semi-nested PCR, the presence of astrovirus (AstV) and norovirus genogroup II (NoV GII) in mussels (Mytella falcata) and oysters (Crassostrea brasiliana) collected in two sites of the Lagunar Complex of Cananéia, State of São Paulo, Brazil. A total of 150 samples of mussels and oysters (75 samples each) were analyzed. AstV was not identified in any shellfish sample. NoV GII was detected in 21 samples (14%), 8 mussel samples (38%), and 13 oyster samples (62%). From the 21 positive samples, 16 were analyzed by nucleotide sequencing. The molecular characterization revealed that Brazilian samples were grouped into clades along with other sequences from Brazil, Japan, and Mexico. There was 93.8–100% amino acid sequence similarity among the samples in this study and > 94.9% when compared with the strains isolated from clinical cases in Brazil. The screening of shellfish for the presence of health-significant enteric viruses can help prevent outbreaks among consumers and contribute to the improvement of the estuarine environment.

The objective of this study was to evaluate biochemical parameters and histopathology of liver in Matrinxã (Brycon cephalus) and Pacu (Piaractus mesopotamicus) fish chronically exposed to dietary aflatoxins. Fish feed was artificially contaminated with aflatoxins and the treatments were: Control – feed without toxin; Treatment A – feed + 10 μg aflatoxin B₁(AFB₁)/kg; Treatment B – feed + 20 μg AFB₁/kg; and Treatment C – feed + 50 μg AFB₁/kg. Matrinxã and Pacu juvenile fish were placed in tanks for 180 days. Five experimental units per treatment were monthly sampled and submitted to blood collection and removal of hepatic tissue. Thus, twenty blood and liver samples for each species were collected monthly, adding up to 240 samples analysed. To verify biochemical changes, analyses included total proteins, albumin, globulins, aspartate aminotransferase (AST) and alkaline phosphatase (ALP). The hepatic tissue was examined microscopically and the slides presenting histopathological changes were photo-documented. There was effect of treatment (P0.05) was observed in Pacu. A reduction (P1.

The objective of this work was to evaluate the aflatoxins residues on tissues of Pacu (Piaractus mesopotamicus) fish chronically exposed to dietary aflatoxins, also evaluating the effects on fish performance. Aflatoxins were incorporated into the extruded fish feed and the concentrations were confirmed by high performance liquid chromatography (HPLC). The experimental design comprised the following treatments: Control – feed without toxin; Treatment A: feed + 10 μg aflatoxin B₁ (AFB₁)/kg; Treatment B: feed + 20 μg AFB₁/kg and Treatment C: feed + 50 μg AFB₁/kg. Pacu juvenile were allocated in tanks with density of one fish per litter. The experiment lasted 180 days with monthly sampling, and approximately ten fish per treatment were used to compose a sample. Biometric surveys were performed every 30 days, including standard weight and length. Aflatoxins were detected and quantified in fish muscle and liver by HPLC, using immunoafinity columns. Results showed AFB₁ deposition in the liver throughout the experiment in all treatments, but only treatment C differed significantly (P1 residues at low levels in liver and only a slight amount in fish muscle, it should be noted that accumulation is possible in the Pacu species. The diets contaminated with AFB₁ negatively interfered in weight and length of fish when compared to control. Therefore, it can be concluded that long-term exposure of Pacu to dietary AFB₁ can cause losses to producers.

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 B₁, B₂, G₁ and G₂ 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 B₁ (AFB₁) was detected in 70% liver samples and 43.3% muscle samples, at levels up to 5.70 and 1.13 μg 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. © 2021 Society of Chemical Industry.

The addition of nisin into a gelatin matrix can change properties of the film. The aim of this work was to develop gelatin-based films containing different nisin concentrations in order to study their influence on the film's antimicrobial and physical properties and their rheological properties as a film-forming solution (FFS). The FFS was characterised by rheological assays, and the gelatin-based active films were characterised and assessed by the effects of nisin concentrations on their various properties, including antimicrobial activity. Nisin's concentration affected not only its viscoelastic properties of FFS but also its film solubility in water, film surface roughness and light barrier. The addition of nisin also slightly modified the water contact angle and the mechanical properties of the gelatin films. Finally, the films demonstrated activity against Staphylococcus aureus and Listeria monocytogenes at concentrations above 56 mg of nisin g−1 of gelatin.

The objective of this study was to evaluate the microbiological quality of oysters and mussels grown in Cananéia, Brazil, by analysing mesophiles, psychrothophic bacteria, moulds and yeasts, Staphylococcus aureus, and Salmonella spp., and to compare the efficiency of Compact Dry EC method and the conventional method for counting of total coliforms and Escherichia coli. The microbial analysis showed that the mean values of mesophilic counts were 3.14±0.81 log CFU g⁻¹ for oysters and 3.92±0.90 for mussels; the mean values of psychrophilic counts were 2.78±0.75 log CFU g⁻¹ for oysters and 3.22±0.75 log CFU g⁻¹ for mussels; the mean values of mould and yeast counts were 3.70±0.58 log CFU g⁻¹ for oysters and 3.33±0.81 log CFU g⁻¹ for mussels. Salmonella spp. did not present positive results, and the maximal count of Staphylococcus aureus was 1.7 log CFU g⁻¹, therefore, within the limits established in the legislation. The correlation coefficients between the Compact Dry EC method and conventional method were >0.87 for total coliform and E. coli counts for both types of shellfish. The data in this study show that the Compact Dry EC method is an acceptable alternative to conventional methods for enumeration of total coliforms and E. coli in shellfish.

The present study analyzes influence of two cleaning and disinfection protocols on frequency of Aspergillus spp. in broiler facilities. We conducted an observational study, applying two cleaning and disinfection protocols before housing 960 one-day-old broilers randomly allocated in 32 boxes with 30 birds. We considered two types of housing as independent experiments, which differed as to the bedding. First experiment consisted of new bedding materials, which we reused in second experiment. We applied two different treatments, Common treatment included sweeping organic matter, humidifying residual material with low pressure water, washing with water and neutral detergent, with posterior rinsing. European treatment was according to the standards of the manufacturer of disinfectants. Procedures included dry and humid organic matter removal, humidification, washing with high pressure water, application of detergent, rinsing, and application of two compound disinfectants: glutaraldehyde (250 g/L) + formaldehyde (185 g/L); p-chloro-m-cresol (210 g/L). To evaluate the presence of Aspergillus spp., we collected samples from surfaces and equipment before and after cleaning and disinfection, at 7, 14, 28, and 42 days of experimental period. Mycological assessment included streaking on Petri dishes containing AFPA (Aspergillus Flavus and Parasiticus Agar, Sigma Aldrich®). Common cleaning and disinfection treatment led to a higher presence of fungus in floors and walls (83% vs. 0% p = 0.0030 and 50% vs. 0% p = 0.0450) in first and second experiments, respectively. As this study demonstrates by using the European procedures, performing a detailed cleaning and disinfection protocol reduces the presence of Aspergillus spp. in broiler facilities.