Aflatoxins and fumonisins in conventional and organic corn: a comprehensive review.

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.

In vitro effects of cinnamon, oregano, and thyme essential oils against Escherichia coli and Trueperella pyogenes isolated from dairy cows with clinical endometritis.

Clinical endometritis causes serious economic losses in dairy farms, mainly due to its negative health impact on fertility and milk production, as well as the additional costs of medicines used to treat the affected animals. The therapy for uterine diseases is principally performed with antibiotic treatment; however, its indiscriminate use in dairy herds can favor the increase in the resistance of pathogenic bacteria, leading to treatment failures. In this regard, the use of unconventional treatment may be a good option to reduce the use of antimicrobials in milk production. The objective of the present study was to evaluate the antibacterial activity of cinnamon, oregano, and thyme essential oils, and their combinations, against bovine uterine pathogens. The antibacterial activities of these essential oils were evaluated by the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC), and Fractional Inhibitory Concentration (FIC) indices against Escherichia coli and Trueperella pyogenes, which were isolated from dairy cows with clinical endometritis. Among the essential oils evaluated, the lowest MIC and MBC values observed were obtained with cinnamon essential oil alone. The association among essential oils showed different kinds of interactions, and in some situations, antagonism was observed. This study demonstrated a promising antimicrobial activity of cinnamon's essential oil, indicating that it has excellent potential to be explored as a possible alternative in the treatment of clinical endometritis in dairy cows.

Discovery of Wild Amphibians Infected with Ranavirus in Brazil.

Ranavirus is a double-stranded DNA virus associated with amphibian, fish and reptile die-offs worldwide. International trade of live animals farmed for human consumption, such as the American bullfrog (Lithobates catesbeianus), plays a key role in spreading the pathogen. In Brazil, ranavirus has only been reported in captive bullfrog farms. We found infected tadpoles of both native species and the American bullfrog in the wild, and a case of mass mortality of amphibians and fish potentially associated with ranavirus. Dead animals presented skin ulcerations, hemorrhages, and edemas. We also found an overall prevalence of 37% of the amphibian chytrid in the area, and two bullfrog tadpoles were co-infected with both pathogens. We suggest that the interaction between the two pathogens should be investigated to improve global conservation of ectothermic vertebrates.

Correction: Effects of dietary aflatoxin B1 on accumulation and performance in matrinxã fish (Brycon cephalus).

[This corrects the article DOI: 10.1371/journal.pone.0201812.].

Effects of dietary aflatoxin B1 on accumulation and performance in matrinxã fish (Brycon cephalus).

Aflatoxins (AF) can be cumulative in fish tissues and can influence weight, length, feed intake and survival depending on the species. The aim of this work is to measure performance and aflatoxin levels in tissues of matrinxã (Brycon cephalus) fish chronically exposed to aflatoxin. Aflatoxin was incorporated into fish diets at the following levels: Control Feed + 0 µg AFB1 kg-1; A. Feed + 10 µg AFB1 kg-1; B. Feed + 20 µg AFB1 kg-1; C. Feed + 50 µg AFB1 kg-1. It was used one tank per treatment, each one with 150 juvenile fish, and three replicates within each tank were used for sampling, that was carried out monthly over a period of six months. Aflatoxin was quantified by HPLC in fish liver and muscle after clean up using immunoaffinity columns. Performance was evaluated by using weight, length, consumption and survival rate. Muscle and liver aflatoxin levels were below the limit of detection in all control samples. Aflatoxins B2, G1 and G2 were not detected in any tissues. Traces (values between limits of detection and quantification) of AFB1 were observed in liver tissue in treatment A from day 30 through 90, reaching 0.32 µg AFB1 kg-1 at 150 days of exposure. Treatment B presented traces up to day 60 and had, with a maximum level of 0.39 µg AFB1 kg-1 at 150 days of exposure. Treatment C had aflatoxin residues after day 30, with values ranging from 0.17 to 0.61 µg AFB1 kg-1 during exposure. Muscle samples only had traces of AFB1 in all treatments. Fish was affected by exposure to AFB1 with higher values (P<0.05) for weight and length in treatments A, B and C relative to controls. Therefore, results indicate that matrinxã do not accumulate AFB1 residues in edible tissues, but chronic exposure affects the species.

Species identification and antimicrobial susceptibility profile of bacteria causing subclinical mastitis in buffalo / Identificação de espécies e perfil de susceptibilidade antimicrobiano de bactérias causadoras de mastite subclínica em búfalos

Microorganisms causing subclinical mastitis in water buffalo were isolated from 20 buffalo milk samples at four dairy farms located in central region of São Paulo State, Brazil, through testing of somatic cell count (SCC), standard plate count (SPC), biochemical, PCR assays and antimicrobial profile. The SCC showed average of 721,000 cells/mL in the milk, indicating the presence of subclinical mastitis. The overall average for SPC was 1.8 x 104 CFU/mL. The microorganism most frequently isolation according to biochemical tests were: Staphylococcus epidermidis (17%), Staphylococcus aureus (15%), Bacillus spp. (14%), Acinetobacter spp. (12.5%); with intermediate frequency: Pseudomonas aeruginosa (9.5%); Shigella flexneri (7.0%), Streptococcus spp. (5.5%), Corynebacterium spp. (5.0%), Escherichia coli (4.5%), Serratia marcescens (4.0%), Stenotrophomonas maltophilia (4.0%), and low incidence: Klebsiella rhinoscleromatis (0.5%), Klebsiella ozaenae (0.5%), Tatumella ptyseos (0.5%), Enterobacter cloacae (0.5%). The molecular analysis indicated that samples positive by culture method of the genera Staphylococcus, Streptococcus and E. coli were positive by PCR. Para S. aureus and S. epidermidis the highest percentages of observed sensitivity were gentamicin (100%) and vancomycin (100%); for the genus Streptococcus to gentamicin and oxacillin and E. coli to Ampicilin. These findings may help in the control and treatment of subclinical mastitis in buffaloes and contribute to improving the efficiency and quality of the milk produced.(AU)

Microrganismos causadores de mastites subclínicas em búfalas foram isolados desde 20 amostras de leite de búfalos de quatro granjas leiteiras localizadas na região central do Estado de São Paulo, Brasil, através dos testes contagem de células somáticas (CCS), contagem padrão em placas (CPP), provas bioquímicas, reações de PCR e perfil antimicrobiano. A CCS apresentou uma mediana de 721.000 cel/mL no leite, indicando presença de mastite subclínica. A média geral de CPP foi de 1,8x104 UFC/mL. Os microrganismos com maior frequência de isolamento segundo os testes bioquímicos foram: Staphylococcus epidermidis (17%), Staphylococcus aureus (15%), Bacillus spp. (14%), Acinetobacter spp. (12,5%); frequência intermediaria: Pseudomonas aeruginosa (9,5%); Shigella flexneri (7,0%), Streptococcus spp. (5,5%), Corynebacterium spp. (5,0%), Escherichia coli (4,5%), Serratia marcescens (4,0%), Stenotrophomonas maltophilia (4,0%), e baixa incidência: Klebsiella rhinoscleromatis (0,5%), Klebsiella ozaenae (0,5%), Tatumella ptyseos (0,5%), Enterobacter cloacae (0,5%). A análise molecular indicou que as amostras positivas pelo método de cultura dos gêneros Staphylococcus, Streptococcus e Escherichia coli foram positivas por PCR. Para S. aureus e S. epidermidis os maiores percentuais de sensibilidade observados foram gentamicina (100%) e vancomicina (100%); para o gênero Streptococcus à gentamicina e oxacilina e para E. coli à ampicilina. Este resultados podem ajudar no controle e tratamento da mastite subclínica em búfalos e contribuir para melhorar a eficiência e qualidade do leite produzido.(AU)

Hantavirus pulmonary syndrome, central plateau, southeastern, and southern Brazil.

Hantavirus pulmonary syndrome (HPS) is an increasing health problem in Brazil because of encroachment of sprawling urban, agricultural, and cattle-raising areas into habitats of subfamily Sigmodontinae rodents, which serve as hantavirus reservoirs. From 1993 through June 2007, a total of 884 cases of HPS were reported in Brazil (case-fatality rate 39%). To better understand this emerging disease, we collected 89 human serum samples and 68 rodent lung samples containing antibodies to hantavirus from a 2,500-km-wide area in Brazil. RNA was isolated from human samples and rodent tissues and subjected to reverse transcription-PCR. Partial sequences of nucleocapsid protein and glycoprotein genes from 22 human and 16 rodent sources indicated only Araraquara virus and Juquitiba virus lineages. The case-fatality rate of HPS was higher in the area with Araraquara virus. This virus, which may be the most virulent hantavirus in Brazil, was associated with areas that have had greater anthropogenic changes.

Protection levels of vaccinated pigeons (Columba livia) against a highly pathogenic Newcastle disease virus strain.

The purposes of this study were to model a vaccination regimen for Newcastle disease virus (NDV) in pigeons, and to evaluate the susceptibility and behavior of vaccinated birds against a highly pathogenic NDV Brazilian strain. Antibody response was assessed by means of hemagglutination inhibition test (HI), and viral genome excretion by means of RT-PCR. Vaccinal strains (La Sota and Ulster) induced high antibody titers without any adverse effects, both in inoculated and in sentinel birds. A viral strain pathogenic for chickens did not produce clinical signs of the disease in experimentally infected pigeons. Only 4 out of 10 vaccinated pigeons shed NDV genome, and just for two days. Results confirmed the high infectivity of the vaccinal strains used, as all nonvaccinated pigeons showed antibody titers as high as those of vaccinated birds.