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The aim of this work was to test 101 strains of E. coli for virulence factors associated with enterotoxigenic and enterohemorrhagic pathotypes of E. coli isolated from diarrheic and non-diarrheic calves. The virulence factors of E. coli Stx1 (Shiga toxin), Stx2, Ehly (Enterohemolysin), the eae gene, LT-II (heat-labile enterotoxin), STa (heat-stable toxin), and adhesins K99 and F41 were detected by PCR. Serogroups were determined by serological methods and Stx production was observed by biological assays in Vero cells. The frequency of the eae gene was higher in isolates from diarrheic calves (35/58, 60.3%) than in non-diarrheic calves (8/43, 18.6%; P < 0.001). The gene for Stx1 occurred at high frequencies in the diarrheic strains (24/58, 41.3%) as well as in non-diarrheic (19/43, 44.2%) ones and all strains that were Stx positive by PCR showed cytotoxicity in Vero cells. Stx2 was found in ten strains, Ehly in eight strains, and LT-II in only two strains. Twenty-eight strains were negative for all of the PCR assays, including for F41 and K99 adhesins. The serogroups O7, O23, O4, O8, O153 and O156 were observed most frequently. Our results show that strains of E. coli isolated from cattle have similar virulence factors genes to strains isolated from cases of diseases in humans and may be a source of potentially pathogenic STEC for humans.KEY WORDS: Escherichia coli, diarrhea, cattle, PCR, shiga toxin. RESUMO DETECÇÃO DE GENES DE VIRULÊNCIA EM AMOSTRAS DE ESCHERICHIA COLI ISOLADAS DE FEZES DE BEZERROS COM E DIARREIA NO BRASIL. O objetivo deste trabalhofoi detectar em 101 amostras de E. coli isoladas de bezerros com e sem diarreia, fatores de virulência associados aos patotipos de E. coli enterotoxigênica e enterohemorrágica. Os fatores de virulência de E. coli Stx1 (Shiga toxina), Stx2, Ehly (Enterohemolisina), o gene eae, LT-II (enterotoxina termolábil), STa (toxina termo-estável), e adesinas K99 e F41 foram detectados por PCR. Os sorogrupos foram determinados por métodos sorológicos e a produção de Stx foi observada através de ensaios biológicos em células Vero. A frequência de detecção do gene eae foi maior nos isolados de bezerros com diarreia (35/58, 60,3%) do que em bezerros saudáveis (8/43, 18,6%; P < 0.001). O gene da toxina Stx1 foi detectado em alta frequência em amostras diarreicas (24/58, 40,3%), bem como em amostras não diarréicas (19/43, 44,2%) e todas as amostras positivas para toxina Stx em PCR mostraram citotoxicidade em células Vero. Stx2 foi encontrada em dez amostras, Ehly em oito amostras, e LT-II em duas amostras. Vinte e seis amostras foram negativas para todos os ensaios de PCR, incluindo para as adesinas F41 e K99. Os sorogrupos O7, O23, O4, O8, O153 e O156 foram detectados com maior frequência. O trabalho mostra que amostras de E. coli isoladas de bovinos apresentam fatores de virulência semelhantes à isolados de casos de doenças em humanos e possivelmente é uma fonte para STEC potencialmente patogênicas para humanos.

Para o cultivo da cenoura é importante conhecer a adaptação das cultivares de acordo com as condições climáticas do local e a preferência do consumidor. Com o objetivo de avaliar o desempenho e a aceitação, detectando assim a preferência dos consumidores a diferentes cultivares de cenoura em sistema de cultivo orgânico, realizou-se o presente trabalho. Avaliou-se o desempenho das cultivares de cenoura em Dois Vizinhos (PR). O delineamento experimental utilizado foi blocos casualizados com cinco repetições e quatro tratamentos para a época de inverno (cvs Nantes, Shin Kuroda, Danvers e Flaker) e cinco tratamentos para o verão (cvs Shin Kuroda, Kuronan, Brasília, Esplanada e Carandaí). Avaliou-se a resistência à queima das folhas (Alternaria dauci), incidência de ombro verde, sólidos solúveis totais, produtividade e aceitabilidade, por meio de análise sensorial das cenouras in natura e em conserva tipo picles. Para o cultivo de inverno a cultivar Nantes resultou em maior produtividade (29,02 t ha-1) e para o cultivo de verão a produtividade da cultivar Esplanada foi superior (32,0 t ha-1) às demais cultivares, que não diferiram estatisticamente entre si. A cv. Esplanada apresentou maior resistência à queima das folhas e menor percentagem (5,6%) de ombro verde. As características organolépticas das cultivares apresentaram boa aceitabilidade pelos consumidores participantes.

Ethanol can inhibit ethylene and retard decay of several fruit. However, the effect of ethanol on ethylene and oxidative stress has not yet been observed in bananas. In this work, the effect of ethanol (vapor phase) on physiology and conservation of the banana cv. 'Prata' was investigated. Initially, a group of bananas was analyzed during 8 h of exposure to ethanol, and then another group of bananas was exposed to ethanol for 4 h and then analyzed during 12 days of storage. Ethanol and ethylene concentrations, respiration rate, superoxide dismutase and catalase activities, physico-chemical characteristics and fruit decay were evaluated. Ethanol reduced ethylene production and respiration rate of the banana only when it reached 4 h of exposure, and this was associated with a maximum absorption of ethanol in the fruit peel. Ethanol increased superoxide dismutase and catalase activities from fruit peel only in the first 2 h of exposure to ethanol, i.e. ethanol did not generate significant oxidative stress. During storage, ethanol inhibited ethylene production and was also able to delay fruit decay, but it was not able to influence the respiration rate, conversion of sugars, and fresh weight loss of the fruits. This study showed that ethanol vapor has an inhibitory effect on ethylene metabolism, but it has no potential to control post-harvest ripening of the banana cv. 'Prata'. On the other hand, ethanol delays decay, and this extends fruit shelf life, which is commercially advantageous.

Introduction: The diarrhea associated with gastroenteritis is a major cause of morbidity and mortality worldwide, affecting mainly infants. The characterization of both viral and bacterial agents associated with gastroenteritis can establish policies for surveillance, prevention and treatment of infections. Group A rotaviruses are the major infectious agent associated with dehydration in children, followed by pathotypes of Escherichia coli. There are three main types of clinical infections caused by E. coli strains that have acquired virulence genes: (i) enteric and diarrheal diseases, (ii) urinary tract infections, and (iii) sepsis and meningitis. Methodology: In this study, the objective was to identify the presence of rotavirus and diarrhogenic E. coli in the feces of children 4 to 14 months of age who displayed no gastroenteritis symptoms and stayed all day in a day-care center. We analyzed 188 samples using PAGE and PCR to identify rotaviruses and E. coli virulence genes, respectively. Results: Thirty-six samples (19.1%) were positive for at least one pathotype of E. coli. Nineteen were identified to be of the EPEC group and fifteen of the EAEC group. Rotaviruses were not identified. Conclusions: As EPEC and EAEC are potential pathogens for children less than one year of age or immunocompromised individuals, our results show the importance of appropriate monitoring by public health agencies.  In the situation that we have studied, children can be considered asymptomatic carriers of these pathogens and can transmit them to other susceptible children.