Antistaphylococcal and antioxidant activities of bacteriocinogenic lactic acid bacteria and essential oil in goat coalho cheese.

AIMS: Bacteriocinogenic lactic acid bacteria (LAB) isolates and Croton heliotropiifolius essential oil (EO) were used to inhibit Staphylococcus aureus subsp. aureus and enhance the antioxidant action in goat coalho cheese (GCC). METHODS AND RESULTS: Lactic acid bacteria isolates were selected for their inhibitory capacity against S. aureus subsp. aureus, safety, existence of bacteriocin-encoding genes, bacteriocinogenic activity, and its antistaphylococcal action. The staphylococcal inhibition capacity of C. heliotropiifolius EO was also verified. Three cheeses were prepared containing S. aureus subsp. aureus (GCC SA), S. aureus subsp. aureus + LAB (GCC SA + LAB), and S. aureus subsp. aureus + EO (GCC SA + EO). Samples were analysed on days 0, 7, 14 and 21. Based on the screening, three LAB isolates were selected and identified as Enterococcus faecium. In GCC, the smallest population of S. aureus subsp. aureus was found until the 17th in the GCC SA + EO and from the 18th in the GCC SA + LAB. Total phenolic content and antioxidant activity increased over time in GCCs. CONCLUSIONS: Autochthonous bacteriocinogenic LAB and C. heliotropiifolius EO are natural resources of the Caatinga, an exclusively Brazilian biome that predominates in the northeast of the country, with the potential to reduce the presence of S. aureus and increase the antioxidant activity in the GCC. SIGNIFICANCE AND IMPACT OF THE STUDY: Goat coalho cheese is a product of cultural importance in northeastern Brazil. The process of obtaining the GCC is manual, and there is a high frequency of S. aureus in the product. Resources of the Caatinga with biofunctional properties can be tested to reduce the risk of staphylococcal toxins, and contribute to the nutritional value of the GCC, maintaining regional characteristics and respecting the local cultural tradition. LAB and C. heliotropiifolius EO contribute to the incorporation of bioactive substances and microbiological quality, generating a value-added GCC with exclusive resources of the Caatinga.

Lactic Acid Bacteria as Biological Control of Staphylococcus aureus in Coalho Goat Cheese.

The aim of this study is to investigate the bacterial population in coalho goat cheese produced in the semi-arid northeast region of Brazil, to analyse the antibiotic resistance profiles of the identified pathogenic bacteria, to detect the staphylococcal enterotoxin genes and to evaluate the addition of autochthonous lactic acid bacteria (LAB) with technofunctional properties for the control of Staphylococcus aureus growth. In the analysed samples, strains of Escherichia coli (N=11), Salmonella spp. (N=18), Listeria spp. (N=6) and S. aureus (N=9) were classified as multidrug resistant (MDR). The most commonly isolated pathogen from the studied coalho goat cheese was S. aureus. Its isolates were positive for the genes encoding enterotoxins A (sea), B (seb), C (sec) and D (sed). The autochthonous LAB with the potential to inhibit S. aureus were identified as Enterococcus faecium. These strains were selected for in vitro tests of protective, safety, technological and functional properties. In the coalho goat cheese food matrix, these selected autochthonous LAB were able to reduce the enterotoxigenic MDR S. aureus load by approx. 3 log units.

Selection of autochthonous lactic acid bacteria from goat dairies and their addition to evaluate the inhibition of Salmonella typhi in artisanal cheese.

This study aimed to select autochthonous lactic acid bacteria (LAB) with probiotic and functional properties from goat dairies and test their addition to artisanal cheese for the inhibition of Salmonella typhi. In vitro tests, including survival in the gastrointestinal tract (GIT), auto- and co-aggregation, the hemolytic test, DNase activity, antimicrobial susceptibility, antibacterial activity, tolerance to NaCl and exopolysaccharide (EPS), gas and diacetyl production were conducted for sixty isolates. Based on these tests, four LAB isolates (UNIVASF CAP 16, 45, 84 and 279) were selected and identified. Additional tests, such as production of lactic and citric acids by UNIVASF CAP isolates were performed in addition to assays of bile salt hydrolase (BSH), ß-galactosidase and decarboxylase activity. The four selected LAB produced high lactic acid (>17 g/L) and low citric acid (0.2 g/L) concentrations. All selected strains showed BSH and ß-galactosidase activity and none showed decarboxylase activity. Three goat cheeses (1, 2 and control) were produced and evaluated for the inhibitory action of selected LAB against Salmonella typhi. The cheese inoculated with LAB (cheese 2) decreased 0.38 log10 CFU/g of S. Typhy population while in the cheese without LAB inoculation (cheese 1) the pathogen population increased by 0.29 log units. Further, the pH value increased linearly over time, by 0.004 units per day in cheese 1. In the cheese 2, the pH value decreased linearly over time, by 0.066 units per day. The cocktail containing selected Lactobacillus strains with potential probiotic and technological properties showed antibacterial activity against S. typhi in vitro and in artisanal goat cheese. Thus, goat milk is important source of potential probiotic LAB which may be used to inhibit the growth of Salmonella population in cheese goat, contributing to safety and functional value of the product.

Performance and meat quality of broiler chickens that are fed diets supplemented with Agaricus brasiliensis mushrooms.

This trial was performed to study the use of the mushroom Agaricus brasiliensis as an alternative additive to antimicrobial growth promoters in broiler chicken diets and to assess the quality of the broiler chicken breast meat of birds that are fed diets containing this fungus. Thus, 595 1-day-old chicks were reared in reused poultry litter without anticoccidial and antimicrobial additives. The results showed that a concentration of 1.6 g mushrooms/kg diet was ideal for these birds because it provided better bird performance. When the birds' immune system organs were analyzed, it was found that the addition of both mushrooms influenced the immune system organs of these broiler chickens. Adding A. brasiliensis to broiler chicken diets did not compromise breast meat quality.

Probiotic potential of Enterococcus hirae in goat milk and its survival in canine gastrointestinal conditions simulated in vitro.

In canine nutrition, the use of goat nutraceutical dairy products is an innovative proposal. Therefore, the objective of this study was to prepare fermented goat milk with probiotic potential in dogs in an in vitro model. A total of 40 lactic acid bacteria (LAB) species were grown, of which 30 were CAP isolates originally from goat milk and 10 were CAN isolates originally from fecal material of newborn dogs. The isolates were selected based on resistance to the simulated canine gastrointestinal condition and acidifying ability. After this preliminary screening, the analyses were performed regarding ß-galactosidase and exopolysaccharide formation, diacetyl production, adhesion proteins Mub and mapa, hydrophobicity, DPPH assay, virulence and antibiotic resistance. With these evaluations, four LAB isolates were identified using sequencing of the 16S rRNA gene. These were identified as Enterococcus hirae and were used to produce fermented goat milk. For statistical analysis, the data were analyzed using the Scott-Knott test and also submitted to analysis of variance and the Tukey test (P < 0.05). In the evaluation of goat milk fermented with E. hirae and control, over the 36-day storage period there was a reduction in pH and an increase in acidity, and higher levels of LAB were observed in goat milk fermented with E. hirae. Therefore, both these E. hirae isolates and the fermented goat milk produced showed satisfactory results in vitro, demonstrating probiotic efficiency and food safety for dogs.

Screening of Lactobacillus isolated from pork sausages for potential probiotic use and evaluation of the microbiological safety of fermented products.

The aim of this study was to select strains of Lactobacillus isolated from pork sausage for use as probiotics. Lactobacillus isolates were evaluated in tests based on probiotic characteristics and microbiological safety. The UFLA SAU 14, 52, and 91 isolates were differentiated by coaggregation with Listeria monocytogenes, production of lactic acid, and survival at pH 2. UFLA SAU 172 and 187 isolates had high levels of coaggregation with Salmonella Typhi and Escherichia coli, tolerance to pancreatic fluid, and adhesion to chloroform. UFLA SAU 20 and 34 isolates were characterized by exopolysaccharide production, autoaggregation, and resistance to simulated intestinal fluid. UFLA SAU 185, 238, and 258 isolates exhibited resistance to bile and adhesion to xylene. A cocktail of these 10 Lactobacillus isolates with potential probiotic properties was inoculated into pork sausage and inhibited the growth of L. monocytogenes.

Verification of good practices in food establishments in Petrolina, semi-arid region of Pernambuco, Brazil / Verificação das boas práticas nos estabelecimentos de alimentos em Petrolina, na região semiárida de Pernambuco, Brasil

This study was conducted jointly with the Municipal Sanitary Surveillance Agency of Petrolina, in the period of August-October 2013, to evaluate the hygienic-sanitary conditions of food producing and commercializing establishments in the municipality of Petrolina. A total of 300 food manufacturer/trader establishments were evaluated based on a Good Manufacturing Practices (GMP) checklist. The evaluation was based on 25 items. The data were computed as 0 for nonconformity and 1 for conformity to the GMP checklist. Data from all districts were analyzed by Principal Component Analysis (PCA). Items such as presence of lamp protectors, clean windows and screens, presence of SOP and training programs for handlers, use of aprons, caps, gloves and disposable towels, and performing periodic examinations of the establishments were evaluated. Fourteen evaluation items showed significant differences (P<0.05) for frequency of conforming and 9 for nonconforming. The PCA identified five city districts (Centro Norte, Areia Branca, Santa Luzia, Rio Corrente and São Gonçalo) in the municipality that used GMP in their establishments. These results highlight the need to redouble efforts in establishments to ensure the safety of products offered.

Este estudo foi realizado em conjunto com a Agência Municipal de Vigilância Sanitária de Petrolina, no período de agosto a outubro de 2013, para avaliar as condições higiênico-sanitárias de produção e comercialização de alimentos nos estabelecimentos municipais de Petrolina. Um total de 300 estabelecimentos fabricante/comerciante de alimentos foi avaliado com base em uma lista de verificação de Boas Práticas de Fabricação (BPF). A avaliação foi baseada em 25 itens. Os dados foram computados como 0 para a não-conformidade e 1 para a conformidade segundo a lista de verificação. As respostas para as observações foram obtidas por Análise de Componentes Principais (ACP). Itens como protetores de lâmpadas, limpeza das janelas e telas, presença de programas de higiene operacional, curso de formação para manipuladores, o uso de aventais, bonés, luvas e toalhas descartáveis e realização de exames médicos periódicos dos manipuladores foram avaliados. Quatorze itens de avaliação mostraram diferenças significativas para frequência de conformidade e 9 para não-conformidade. A ACP identificou cinco regiões da cidade (Centro Norte, Areia Branca, Santa Luzia, Rio Corrente e São Gonçalo) no município que utilizam BPF em seus estabelecimentos. Estes resultados destacam a necessidade de redobrar os esforços nos estabelecimentos para garantir a inocuidade dos produtos oferecidos.

In situ inhibition of Escherichia coli isolated from fresh pork sausage by organic acids.

The main aim of this study was to evaluate the inhibitory effect of different concentrations of organics acids citric, lactic, acetic, and propionic on E. coli isolated from pork sausage. Two experiments were performed in vitro, respectively: agar disc diffusion and minimum inhibitory concentration (MIC) determination. In agar disc diffusion, the minimum concentration of 1.29 M of citric acid inhibits bacterial growth. There was no statistically significant difference in the MIC of citric and lactic acids; citric and lactic acids were more effective than acetic and propionic acids. Based on in vitro results, lactic and citric acids were added to pork sausages with E. coli. The addition of citric acid caused a significant reduction (P < 0.01) in the pH of the sausages. Citric acid was most effective 15 d after inoculation; E. coli counts were reduced by 4.53 log units compared with time 0. Due to late inhibitory action of citric acid in the study, its effect may be more effective over E. coli in sausage that requiring longer storage, such as fermented sausages.

Evaluation of adhesive properties of presumptive probiotic Lactobacillus plantarum strains / Avaliação das propriedades de adesão de presumíveis estirpes probióticas de Lactobacillus plantarum

Thirty-two strains of Lactobacillus plantarum UFLA SAU from pork sausages, pre-selected for some features for probiotic application, were utilized in this study to evaluate their adhesive properties and compare the results against the three pathogens also tested. Strains were tested for autoaggregation and coaggregation capacity and Microbial Adhesion To Solvents (MATS) at the time intervals of 0, 1, 2, 3 and 4 h. Our findings revealed that UFLA SAU strains have a high autoaggregative capacity and coaggregative ability with pathogens, especially Listeria monocytogenes. In relation to adhesion to solvents, in general, L. plantarum strains showed hydrophilic cell surface properties and an important electron donor and basic character. Adhesive properties were markedly separated for the strains under study by Principal Component Analysis software. UFLA SAU 132, 226 and 87 were differentiated by autoaggregation ability. UFLA SAU 11 and Listeria monocytogenes were characterized by adhesion to solvents. UFLA SAU 14, 18 and 172 showed high coaggregation with Escherichia coli, Salmonella Typhi and Listeria monocytogenes. In comparison to the pathogens tested, many UFLA SAU strains presented higher adhesive capacity. These tests should be used for screening and identifying potentially adherent microorganisms. Adhesive properties are important features for the choice of probiotic strains and confer various applications, such as in the pharmaceutical (therapeutic or prophylactic) and food (functional foods) industries.

Trinta e duas estirpes de linguiça suína, Lactobacillus plantarum UFLA SAU, pré-selecionadas com algumas características para aplicação probiótica, foram utilizadas neste estudo para avaliar suas propriedades adesivas e comparar os resultados com três patógenos também testados. As estirpes foram testadas para autoagregação, coagregação e capacidade de adesão microbiana aos solventes (MATS) nos tempos de 0, 1, 2, 3 e 4 h. Nossos resultados revelaram que estirpes UFLA SAU apresentam alta capacidade autoagregativa e coagregativa com patógenos, especialmente com Listeria monocytogenes. Em relação à adesão aos solventes, de um modo geral, as estirpes de L. plantarum mostraram propriedades hidrofílicas de superfície celular e um importante caráter básico e elétron doador. Propriedades adesivas foram marcadamente separadas para as estirpes em estudo através da Análise de Componentes Principais. UFLA SAU 132, 226 e 87 foram diferenciadas pela capacidade de autoagregação. UFLA SAU 11 e Listeria monocytogenes foram caracterizadas por adesão aos solventes. UFLA SAU 14, 18 e 172 apresentaram coagregação com Escherichia coli, Salmonella Typhi e Listeria monocytogenes. Em comparação aos patógenos testados, muitas estirpes UFLA SAU apresentaram maior capacidade adesiva. Estes testes podem ser úteis para a triagem e identificação de micro-organismos potencialmente aderentes. Propriedades adesivas são importantes características para a escolha de estirpes probióticas e conferem várias aplicações, tais como nas indústrias: farmacêutica (terapêutico ou profilático) e de alimentos (alimentos funcionais).

Ensaios de padronização do teste ELISA para diagnósticoda cisticercose bovina utilizando antígenos de larvade Taenia crassiceps / ELISA test standardization for the diagnosis of bovine cysticercosis employing Taenia crassiceps metacestode antigens

Os antígenos total e vesicular de Taenia crassiceps e soros-controle de bovinos positivos e negativos para a cisticercose foramcomparados por meio de alguns parâmetros de padronização do teste ELISA, visando avaliar o seu desempenho no diagnósticoda referida doença. Os parâmetros avaliados foram: diferentes concentrações dos antígenos, diluições de soros e conjugados,marcas de placa e substâncias bloqueadoras das placas. As diluições 1:25 de soro e 1:2.500 de conjugado para o antígenode líquido vesicular e 1:5.000 para o antígeno total, o leite desnatado e as maiores concentrações dos antígenos testadas (1,2 e 4 µg/orifício) foram os critérios de padronização que proporcionaram maior diferenciação entre soros positivos e negativos,conseqüentemente, melhor desempenho do teste ELISA.

Using the cyst fluid and the total antigens of Taenia crassiceps and positive and negative bovine control sera, some standardizationparameters of one ELISA were compared, in order to evaluate its performance in the diagnosis of the bovine cysticercosis. Thereferred parameters were different antigen concentrations, dilutions of sera and conjugated, plate marks and blocking substances.The 1:25 dilution sera and 1:2.500 dilution conjugated for the cyst fluid antigen and 1:5.000 for the total antigen, the skimmedmilk and the largest antigens concentrations (1, 2 and 4 µg/well) improved the differentiation among positive and negative sera,consequently, they were the best criteria for the bovine cysticercosis determination employing the ELISA.

Detecção de Listeria monocytogenes como subsídio à determinação de pontos críticos de controle no abate de suínos / Detection of Listeria monocytogenes as subsidy to the determination of the critical control points in the swine slaugther

Foram avaliadas quatro etapas do abate de suíno, quanto à presença de Listeria monocytogenes, visando oferecer informações sobre detecção e controle deste agente a serem utilizadas no sistema APPCC. As amostras se constituíram de 120 carcaças suínas. As freqüências de L. monocytogenes após as etapas de evisceração e de resfriamento foram de 3,3 por cento em ambas, não sendo recuperada após a depilação e imediatamente antes da evisceração. Os resultados não revelaram diferença estatística entre as diferentes etapas de abate. A presença de L. monocytogenes nas duas fases caracteriza contaminação, que ocorreu provavelmente a partir de fezes suínas, com possível multiplicação de microrganismo na etapa de refrigeração. Como subsídio ao sistema APPCC, sugere-se um monitoramento nestas duas fases de abate, enquanto PCC (pontos críticos de controle) ou não, com relação à presença de L. monocytogenes.

Prevenção de Yersinia enterocolitica como um perigo microbiológico em fases de abate de suínos / Prevention of Yersinia enterocolitica as a microbiological danger in phases of abates of swines

A transmissão da yersinia enterocolitica ao homem vem sendo atribuída principalmente ao consumo da carne suína. Como é uma bactéria que pode se encontrada em suínos sadios, sobretudo no seu trato gastrintestinal e suas tonsilas, a sua transferência para a carne durante o processo de abate tem sido motivo de preocupação. As amostras constituíram-se de esfregaços superficiais de 120 carcaças de suínos, foram coletadas em um matadouro-frigorífico inspecionado pelo SIF, em diferentes etapas de abate e analisadas pelo método microbiológico convencional. Não foi isolada a bactéria em pesquisa, o que foi atribuído ao alto padrão tecnológico de abate verificado no estabelecimento em questão. Relacionou-se este resultado com a importância dos procedimentos preventivos de controle de Y. enterocolitica, entre outros patógenos, no abate de suínos, quando acompanhado de sistemas eficazes de controle microbiano, como o APPCC, no proteção da saúde pública.

The transmission of the Yersinia enterocolitica to the man has been attributed to the pork consumption. This bacteria can be found in healthy swine. Therefore its transfer for the meat during the slaughter process has been concern reason. The samples were constituted of swabs of 120 swine carcasses, they were collected in a slaughterhouse inspected by federal inspection service, in different slaugther phases and analyzed by the microbiological method. The bacteria was not isolated in this research, that was attributed to the high technological pattern of slaughter verified in the establishment in subject. This result was explained by the preventive procedures of the Y. enterocolitica control in the swine slaughter, when accompanied of effective systems of microbial control, like HACCP, in the public health protection.

Prevenção de Yersinia enterocolitica como um perigo microbiológico em fases de abate de suínos / Prevention of Yersinia enterocolitica as a microbiological danger in phases of abates of swines

A transmissão da yersinia enterocolitica ao homem vem sendo atribuída principalmente ao consumo da carne suína. Como é uma bactéria que pode se encontrada em suínos sadios, sobretudo no seu trato gastrintestinal e suas tonsilas, a sua transferência para a carne durante o processo de abate tem sido motivo de preocupação. As amostras constituíram-se de esfregaços superficiais de 120 carcaças de suínos, foram coletadas em um matadouro-frigorífico inspecionado pelo SIF, em diferentes etapas de abate e analisadas pelo método microbiológico convencional. Não foi isolada a bactéria em pesquisa, o que foi atribuído ao alto padrão tecnológico de abate verificado no estabelecimento em questão. Relacionou-se este resultado com a importância dos procedimentos preventivos de controle de Y. enterocolitica, entre outros patógenos, no abate de suínos, quando acompanhado de sistemas eficazes de controle microbiano, como o APPCC, no proteção da saúde pública.