Jabuticaba (Myrciaria jaboticaba) juice obtained by steam-extraction: phenolic compound profile, antioxidant capacity, microbiological stability, and sensory acceptability.

Jabuticaba (Myrciaria jaboticaba) is a dark-colored fruit native to Brazil that has a desirable flavor and high anthocyanin content. In the present study, jabuticaba juice was produced by steam-extraction and the phenolic compound profile, antioxidant capacity, instrumental color, and microbiological quality were evaluated during 90 days of storage at 25 °C. Cyanidin-3-O-glucoside represented 45% of the total phenolic content of the juice, which reduced with extent of 80% during storage. Total phenolic content of the juice increased by 59% during 90 days of storage, which entailed, average 4.4-fold increase in the content of gallic and ellagic acids. FRAP assay was most sensitive for measuring gallic and ellagic acids, while the TEAC assay was the most sensitive for measuring anthocyanins. Although [Formula: see text] and [Formula: see text] values of jabuticaba juice decreased and [Formula: see text] increased during storage. Jabuticaba juice remained microbiologically stable during storage, and did not support the growth of inoculated Escherichia coli and Salmonella enteritidis, suggesting antimicrobial activity.

Characterization of Enterococcus faecium E86 bacteriocins and their inhibition properties against Listeria monocytogenes and vancomycin-resistant Enterococcus.

In the present scenario of a major demand for new compounds with antimicrobial activity, bacteriocin and bacteriocin-like inhibitory substances (BLIS) are promising tools against deteriorating and pathogenic microorganisms, thus having potential applications in both the food industry and infectious disease control. In the present report, we describe the genetic and phenotypic characteristics of BLIS produced by Enterococcus faecium E86, a strain previously isolated and sequenced by our group, focusing on the structural genes of two bacteriocins identified: enterocin TW21 and enterocin P. Transcription of all four genes associated with the biosynthesis and immunity of enterocin P and enterocin TW21 were confirmed by RT-PCR. However, Sanger sequencing confirmed a truncation of the structural gene of enterocin TW21 due to one base pair deletion (A/T). Thus, although E. faecium E86 was shown to carry two bacteriocinogenic gene clusters, only one cluster encodes a functional bacteriocin, enterocin P. Enterocin P was able to inhibit different strains of Listeria monocytogenes and vancomycin-resistant enterococci (both Enterococcus faecalis and Enterococcus faecium), showing intense bacteriolytic activity, in most cases.

Microbiological, technological and therapeutic properties of kefir: a natural probiotic beverage.

Kefir is a fermented milk beverage produced by the action of bacteria and yeasts that exist in symbiotic association in kefir grains. The artisanal production of the kefir is based on the tradition of the peoples of Caucasus, which has spread to other parts of the world, from the late 19(th) century, and nowadays integrates its nutritional and therapeutic indications to the everyday food choices of several populations. The large number of microorganisms present in kefir and their microbial interactions, the possible bioactive compounds resulting of microbial metabolism, and the benefits associated with the use this beverage confers kefir the status of a natural probiotic, designated as the 21(th) century yoghurt. Several studies have shown that kefir and its constituents have antimicrobial, antitumor, anticarcinogenic and immunomodulatory activity and also improve lactose digestion, among others. This review includes data on the technological aspects, the main beneficial effects on human health of kefir and its microbiological composition. Generally, kefir grains contain a relatively stable and specific microbiota enclosed in a matrix of polysaccharides and proteins. Microbial interactions in kefir are complex due to the composition of kefir grains, which seems to differ among different studies, although some predominant Lactobacillus species are always present. Besides, the specific populations of individual grains seem to contribute to the particular sensory characteristics present in fermented beverages. This review also includes new electron microscopy data on the distribution of microorganisms within different Brazilian kefir grains, which showed a relative change in its distribution according to grain origin.

Enterococcus spp. Resistant to Multiple Antimicrobial Drugs and Determination of Fecal Contamination Levels in Mangrove Oysters (Crassostrea rhizophorae)

ABSTRACT The aim of this study was to determine and compare the Most Probable Number (MPN) of Total Coliforms (TC), Escherichia coli and Enterococcus spp. and to characterize the antimicrobial resistance profiles of Enterococcus spp. isolated from oysters collected in the Barra de Guaratiba Mangrove, Rio de Janeiro, Brazil. The enumeration of E. coli has been used to indicate fecal contamination and hygienic-sanitary conditions of bivalve molluscs. Enterococci are capable to transfer several antimicrobial resistance genes to pathogenic bacteria, including those from Gram-negative group. The oysters were bought from local fishermen and a total of 123 individuals were analyzed. The TC, E. coli and Enterococcus spp. MPN mean were 26,300/100 g, 3,260/100 g and 2,820/100 g, respectively. The only correlation found was between TC and E. coli. Two strains of Enterococcus spp. were resistant to three different antimicrobial categories, including a high level resistance to streptomycin. One strain presented intermediate resistance to vancomycin. The E. coli levels exceeded the limits established by international legislation. This microbiological contamination in oysters reflects the water pollution and indicates a probable contamination of other seafood species from this mangrove, which can represent a risk for consumers and a threat to the environment and public health.

Tapered plastic optical fiber-based biosensor--tests and application.

Cells detection is crucial in microbiological analysis of clinical, food, water or environmental samples. However, currently employed methods are time consuming. Plastic optical fiber (POF) biosensors consist in a viable alternative for rapid and inexpensive scheme for detection. In order to study the sensitivity of tapers for microbiological detection, geometric parameters are studied, such as the taper waist diameter since the formation of taper regions are the key sensing element in this particular type of sensors. In this study, a series of POF taper sensors were prepared using a specially developed tapering machine, and the dispersion of geometric dimensions is evaluated, aiming to achieve the best tapering characteristics which will provide a better sensitivity on the sensor response. The fiber tapers that presented the finest results were those constructed in U-shaped (bended) configurations, with taper waist diameters ranging from 0.40 mm up to 0.50 mm. These fiber tapers were used as the main section of the monitoring device, and when chemically treated as immunosensors for the detection of bacteria, yeast and erythrocytes.

A cluster of Listeria monocytogenes infections in hospitalized adults.

BACKGROUND: Listeriosis occurs mainly in persons at extremes of age and with immunocompromising conditions. It is believed that most cases of listeriosis are acquired in the community. A cluster of listeriosis in hospitalized patients prompted the present investigation. METHODS: We conducted a case series study of listeriosis from August 21, 2006, to June 1, 2007, in a hospital in the city of Rio de Janeiro, Brazil. RESULTS: Six patients with Listeria monocytogenes infection were identified: 5 during hospitalization and 1 at a day clinic. By the time the infection was diagnosed, 5 patients had been in the hospital for a mean of 9 days. All patients were elderly (median age, 80 years) and had immunocompromising conditions. Five (83%) patients died. Four patients developed bloodstream infections, 3 caused by serotype 1/2b. Two patients had peritonitis: one caused by serotype 3b and another by serotype 1/2b. Four L monocytogenes isolates belonged to a single pulse-field gel electrophoresis genotype, suggesting a common source. An epidemiologic investigation pointed to the hospital kitchen as the possible contamination. CONCLUSION: Data suggest a health care-associated outbreak of listeriosis and highlight the importance of developing guidelines for prevention and treatment of health care-associated foodborne diseases, especially in hospitals with immunocompromised adult patients.

Microbiological, technological and therapeutic properties of kefir: a natural probiotic beverage

Kefir is a fermented milk beverage produced by the action of bacteria and yeasts that exist in symbiotic association in kefir grains. The artisanal production of the kefir is based on the tradition of the peoples of Caucasus, which has spread to other parts of the world, from the late 19th century, and nowadays integrates its nutritional and therapeutic indications to the everyday food choices of several populations. The large number of microorganisms present in kefir and their microbial interactions, the possible bioactive compounds resulting of microbial metabolism, and the benefits associated with the use this beverage confers kefir the status of a natural probiotic, designated as the 21th century yoghurt. Several studies have shown that kefir and its constituents have antimicrobial, antitumor, anticarcinogenic and immunomodulatory activity and also improve lactose digestion, among others. This review includes data on the technological aspects, the main beneficial effects on human health of kefir and its microbiological composition. Generally, kefir grains contain a relatively stable and specific microbiota enclosed in a matrix of polysaccharides and proteins. Microbial interactions in kefir are complex due to the composition of kefir grains, which seems to differ among different studies, although some predominant Lactobacillus species are always present. Besides, the specific populations of individual grains seem to contribute to the particular sensory characteristics present in fermented beverages. This review also includes new electron microscopy data on the distribution of microorganisms within different Brazilian kefir grains, which showed a relative change in its distribution according to grain origin.

Caracterização microbiológica de lixiviados gerados por resíduos sólidos domiciliares e de serviços de saúde da cidade do Rio de Janeiro / Microbiological characterization of leachate from domestic and hospital solid wastes from Rio de Janeiro city

O presente trabalho consistiu na caracterização microbiológica de lixiviados gerados a partir de resíduos sólidos de serviços de saúde e domiciliares para subsidiar a discussão do tratamento e disposição final diferenciados para os resíduos sólidos de serviços de saúde. Foram analisados: coliformes totais e termotolerantes; Escherichia coli, Enterococos, Salmonella e outras enterobactérias; Pseudomonas aeruginosa, bactérias heterotróficas aeróbias mesófilas, análise da suscetibilidade aos antimicrobianos e pesquisa da atividade antimicrobiana do lixiviado. Foram observadas densidades expressivas das populações microbianas em resíduos sólidos de serviços de saúde e domiciliares com valores que variaram de 10(8) a 10(9). Em ambos os lixiviados, ocorreram estirpes resistentes e sensíveis aos antimicrobianos, e nenhuma delas apresentou resistência a todos os antibióticos testados. Os resultados mostraram semelhanças entre ambos os tipos de resíduos e reforçam a recomendação de codisposição de resíduos sólidos de serviços de saúde e domiciliares em aterros sanitários.

The present paper consisted on the microbiological characterization of leachate generated from solid waste from health services and municipal solid waste. This study aimed to support the discussion about the need for differentiated treatment and disposal for the health services solid waste. The following parameters were selected: total coliforms, thermotolerant coliforms, Escherichia coli, Enterococci, trials for Pseudomonas aeruginosa, and Salmonella and other Enterobacteria, analysis of susceptibility to antimicrobials and research on antimicrobial activity of the leachate. Expressive densities were observed in microbial populations in health services and municipal solid waste, with values ranging from 10(8) to 10(9). In both wastes, resistant and susceptible strains to antimicrobials occurred and none were resistant to all antibiotics tested. Results showed similarities for both types of waste and reinforce the recommendation for health services and municipal solid waste co-disposal in sanitary landfills.

Antimicrobial resistance in food and clinical Aeromonas isolates.

This study highlights the incidence of resistance and the presence of plasmids in human and food isolates of Aeromonas in Brazil. A total of 83 Aeromonas spp. strains (28 isolated from human and 55 from fresh lettuce) were studied. Thirty-five were identified as A. hydrophila complex and 48 as A. caviae complex. All strains were shown to be susceptible to imipenem, amikacin, gentamicin, tobramycin and ciprofloxacin by the disk diffusion method. Resistance to antimicrobial agents was observed in strains of both food and clinical origin. The food strains were resistant to ampicillin/sulbactam, cefoxitin and tetracycline, while the clinical strains presented resistance to ampicillin/sulbactam, cefotaxime, ceftazidime, cefoxitin, sulfamethoxazole/trimethoprim, chloramphenicol and tetracycline. The minimal inhibitory concentrations of chloramphenicol, tetracycline and sulfamethoxazole/trimethoprim were tested by agar dilution. Thirteen strains isolated from vegetables were resistant to tetracycline (MIC 16 microg ml-1). Two A. hydrophila strains and one A. caviae strain presented extracromosomal DNA (3 and 15 kb plasmids, respectively). The tetracycline resistance phenotype determinant was related to the 15 kb plasmid according to cure and transformation experiments.

Estabilidades química, físico-química e microbiológica de suco de laranja cv. "pera" submetido a diderentes condições de estocagem / Chemical, physico-chemical and microbiological stability of orange juice, cv

Este estudo teve como objetivo avaliar as estabilidades química, físico-química e microbiólogica de suco de laranja cv. "Pêra", mmantido em temperatura ambiente, estocado sob refrigeração ou sob congelamento durante diferentes períodos. Determinaram-se os teores de ácido ascórbico e de sólidos solúveis totais, a acidez total titulável e o pH dos sucos. Foram realizadas, também, ascontagens de bactérias heterotróficas aeróbicas mesófilas, fungos miceliais e leveduras, bactérias láticas, coliformes totais e fecais e Salmonella. Os teores de ácido ascórbico e de sólidos solúveis totais dos sucos permaneceram estáveis durante o período de estocagem nas condições estudadas. O mesmo foi observado para acidez total titulável e pH, exceto para os sucos congelados em que houve aqlteração desses parãmetros a partir de 120 dias de estocagemm. Não foram encontrados Salmonella spp. e Coliformes totais e fecais nas amostras estudadas. A contagem inicial das bactérias heterotróficas aeróbicas mesófilas, fungos miceliais e leveduras e bactérias láticas foi de aproximadamente 3 Log UFC/mL. No suco mantido em temperatura ambiente durante 24 horas observou-se aumento de 1,5, 2,3 e 3,4 Log UFC/mL na contagem de bactérias heterotróficas aeróbicas mesófilas, fungos miceliais e leveduras e bactériasláticas, respectivamente. Nos sucos refrigerados, a contagem microbiana não excedeu a inicial até o quarto dia. Nos sucos congelados, a carga microbiana permaneceu inferior à inicial durante 180 dias de estocagem. De acordo com os resultados obtidos, o suco de laranja in natura preserva sua qualidade quando estocado sob refrigeração durante 48 horas ou sob congelamento durante 120 dias.

Leveduras, incluindo patógenos oportunistas, associadas ao mexilhão Mytella guyanensis, no manguezal de Coroa Grande, Baía de Sepetiba, RJ / Yeasts, including opportunistic pathogenic, associates of the Mytella guyanensis, in manguezal Coroa Grande, Baía de Sepetiba, RJ

O número de infecções causadas por leveduras patógenos oportunistas vem aumentando consideravelmente nos últimos anos. Uma vez que os mexilhões, por serem filtradores, podem servir como veículo para transmissão destes microrganismos, o presente trabalho buscou detectar no mexilhão Mytella guyanensis, localizado no sedimento do manguezal de Coroa Grande, Baía de Sepetiba, RJ, a presença destas leveduras. Vinte e seis organismos foram amostrados, todos apresentando contagens acima de 10.000 UFC/100g. Das 76 cepas isoladas, 22 (aproximadamente 30 por cento), pertencem a quatro diferentes espécies de patógenos oportunistas (Candida guilliermondii, Candida krusei, Candida parapsilosis, Candida tropicalis) e podem representar um risco significante à saúde de indivíduos imunodeprimidos.

Leveduras, incluindo patógenos oportunistas, associadas ao mexilhão Mytella guyanensis, no manguezal de Coroa Grande, Baía de Sepetiba, RJ / Yeasts, including opportunistic pathogenic, associates of the Mytella guyanensis, in manguezal Coroa Grande, Baía de Sepetiba, RJ

O número de infecções causadas por leveduras patógenos oportunistas vem aumentando consideravelmente nos últimos anos. Uma vez que os mexilhões, por serem filtradores, podem servir como veículo para transmissão destes microrganismos, o presente trabalho buscou detectar no mexilhão Mytella guyanensis, localizado no sedimento do manguezal de Coroa Grande, Baía de Sepetiba, RJ, a presença destas leveduras. Vinte e seis organismos foram amostrados, todos apresentando contagens acima de 10.000 UFC/100g. Das 76 cepas isoladas, 22 (aproximadamente 30 por cento), pertencem a quatro diferentes espécies de patógenos oportunistas (Candida guilliermondii, Candida krusei, Candida parapsilosis, Candida tropicalis) e podem representar um risco significante à saúde de indivíduos imunodeprimidos.(AU)

Characterization of enterococcus strains isolated from ready-to-eat foods

Treze estirpes de Enterococcus faecalis e 5 de E. faecium isoladas a partir de alimentos foram estudadas em relaçäo a produçäo de termonuclease (TNase), atividade hemolítica em sangue humano e de coelho e sensibilidade a antimicrobianos. Näo foi observada a produçäo de TNase e ß-lactamase, reastência a vancomicina e a altos níveis de aminoglicosídeos

Avaliação microbiológica de frutas e hortaliças frescas, servidas em restaurantes self-sevice privados, da Universidade Federal do Rio de Janeiro / Microbiological evaluation of fruits and fresh salads obtained from self-service restaurants located at the Universidade Federal do Rio de Janeiro

Foi realizada a avaliação da qualidade higiênico-sanitária de 30 amostras de alimentos vegetais crus, sendo 15 de frutas e 15 de hortaliças prontas para o consumo, comercializadas em dois restaurantes de médio porte da Cidade Universitária da Universidade Federal do Rio de Janeiro (UFRJ). As amostras foram analisadas quanto aos seguintes parâmetros: contagem de mesófilos aeróbios totais, coliformes, enterococos, Staphylococcus aureus (incluindo pesquisa de estirpes enterotoxigênicas), bolores e leveduras, pesquisa de Salmonella spp., Shigella spp., sorotipos diarreiogênicos de E. coli, incluindo O157:H7 e avaliação parasitológica. Os resultados indicaram que 12 (92,3 por cento) das amostras de hortaliças e 9 (64,3 por cento) das amostras de frutas analisadas estavam com contagem de coliformes fecais acima do padrão preconizado pela Agência Nacional de Vigilância Sanitária, sendo a presença de Escherichia coli detectada em 12 (40 por cento) do total de amostras. A pesquisa de E. coli O157:H7 foi negativa em todas as amostras analisadas. Entretanto, outros sorotipos diarreiogênicos foram detectados (monovalente O26, O55, O111, O119, O124, O125, O127, O142, polivalente clássica A, polivalente clássica B, polivalente clássica C, polivalente invasora A, polivalente invasora B). A pesquisa de Salmonella spp. revelou a presença deste patógeno em 5 (16,6 por cento) das 30 amostras analisadas. Staphylococcus aureus foi detectado em 16 amostras (53,3 por cento), sendo que 2 estirpes produtoras de enterotoxina foram isoladas de salada de alface. Uma delas, produtora de enterotoxinas A e B, foi detectada em contagem de 3,0 x 100 UFC/g, e a outra produtora de enterotoxina A apresentou contagem de 1,1 x 1000 UFC/g. A freqüência de enterococos não apresentou correlação com os níveis de contaminação por coliformes fecais. Em nenhuma das amostras foi detectada a presença de parasitas.(AU)

Avaliação microbiológica de frutas e hortaliças frescas, servidas em restaurantes self-sevice privados, da Universidade Federal do Rio de Janeiro / Microbiological evaluation of fruits and fresh salads obtained from self-service restaurants located at the Universidade Federal do Rio de Janeiro

Foi realizada a avaliação da qualidade higiênico-sanitária de 30 amostras de alimentos vegetais crus, sendo 15 de frutas e 15 de hortaliças prontas para o consumo, comercializadas em dois restaurantes de médio porte da Cidade Universitária da Universidade Federal do Rio de Janeiro (UFRJ). As amostras foram analisadas quanto aos seguintes parâmetros: contagem de mesófilos aeróbios totais, coliformes, enterococos, Staphylococcus aureus (incluindo pesquisa de estirpes enterotoxigênicas), bolores e leveduras, pesquisa de Salmonella spp., Shigella spp., sorotipos diarreiogênicos de E. coli, incluindo O157:H7 e avaliação parasitológica. Os resultados indicaram que 12 (92,3 por cento) das amostras de hortaliças e 9 (64,3 por cento) das amostras de frutas analisadas estavam com contagem de coliformes fecais acima do padrão preconizado pela Agência Nacional de Vigilância Sanitária, sendo a presença de Escherichia coli detectada em 12 (40 por cento) do total de amostras. A pesquisa de E. coli O157:H7 foi negativa em todas as amostras analisadas. Entretanto, outros sorotipos diarreiogênicos foram detectados (monovalente O26, O55, O111, O119, O124, O125, O127, O142, polivalente clássica A, polivalente clássica B, polivalente clássica C, polivalente invasora A, polivalente invasora B). A pesquisa de Salmonella spp. revelou a presença deste patógeno em 5 (16,6 por cento) das 30 amostras analisadas. Staphylococcus aureus foi detectado em 16 amostras (53,3 por cento), sendo que 2 estirpes produtoras de enterotoxina foram isoladas de salada de alface. Uma delas, produtora de enterotoxinas A e B, foi detectada em contagem de 3,0 x 100 UFC/g, e a outra produtora de enterotoxina A apresentou contagem de 1,1 x 1000 UFC/g. A freqüência de enterococos não apresentou correlação com os níveis de contaminação por coliformes fecais. Em nenhuma das amostras foi detectada a presença de parasitas.

Intoxicaçäo por Staphylococcus aureus provocada por carne de peru defumada / Staphylococcus aureus infections caused by smoked meat of turkey

Carne de peru defumada preparada numa confeitaria do bairro de Laranjeiras, RJ, apresentado 4,0 x 10**7 Staphylococcus aureus enterotoxigênico/g, provocou intoxicaçäo em 4 pessoas de mesma família