Food handlers: an important reservoir of protozoans and helminth parasites of public health importance / Manipuladores de alimentos: um importante reservatório de protozoários e helmintos parasitas de importância para a saúde pública

Food handlers plays a primary role in the transmission of pathogenically important protozoans and helminth parasites. This study was aimed to evaluate the prevalence of intestinal pathogenic protozoans and helminth parasites among food handlers in and around University of Malakand, Lower Dir, Pakistan. Stool samples were collected from 642 food handlers (all of male) in a cross-sectional study from January to November, 2017. Wet Mount Techniques and concentration methods by using salt and formol­ether solutions. Three hundred and eighty four cases (59.8%) were found infected with one more parasites. Most of the individuals were found infected with helminth (47.6%) as compared to intestinal protozoans (0.93%). Seventy two cases (11.2%) of the cases presented mixed infection with both intestinal protozoan and helminth parasites. The order of prevalence for intestinal helminth was Ancylostoma duodenale (n = 258, 40.1%), followed by Taeniasa ginata (n=96, 14.9%) Ascaris lumbricoides (n = 54, 8.40%) and Trichuris trichura (n=30, 4.60%). For intestinal protozoa, Entamoeba histolytica/díspar (n = 36, 5.64%) was the only protozoan detected. Mono-parasitism was higher than poly-parasitism. Family size income and education level were the factors significantly (P<0.05) associated in the parasites prevalence. Current research showed that IPIs are primarily the foodborne pathogens still an important public health problem in Pakistan. Effective control programs on parasitic diseases transfer and their associated factors are recommended.

Os manipuladores de alimentos desempenham um papel fundamental na transmissão de protozoários e helmintos parasitas patogenicamente importantes. Este estudo teve como objetivo avaliar a prevalência de protozoários patogênicos intestinais e helmintos parasitas entre manipuladores de alimentos na Universidade de Malakand, Lower Dir, Paquistão. Amostras de fezes foram coletadas de 642 manipuladores de alimentos (todos do sexo masculino) em um estudo transversal de janeiro a novembro de 2017. Técnicas de montagem úmida e métodos de concentração usando soluções de sal e formol-éter. Trezentos e oitenta e quatro casos (59,8%) foram encontrados infectados com mais um parasita. A maioria dos indivíduos foi encontrada infectada por helmintos (47,6%) em comparação com protozoários intestinais (0,93%). Setenta e dois casos (11,2%) dos casos apresentavam infecção mista com protozoários intestinais e helmintos parasitas. A ordem de prevalência de helmintos intestinais foi Ancylostoma duodenale (n = 258, 40,1%), seguido por Taeniasa ginata (n = 96, 14,9%) Ascaris lumbricoides (n = 54, 8,40%) e Trichuris trichura (n = 30, 4,60 %). Para protozoários intestinais, Entamoeba histolytica / dispar (n = 36, 5,64%) foi o único protozoário detectado. Monoparasitismo foi maior do que poliparasitismo. A renda familiar e o nível de escolaridade foram os fatores significativamente (P <0,05) associados na prevalência de parasitos. A pesquisa atual mostrou que os IPIs são principalmente os patógenos de origem alimentar, ainda um importante problema de saúde pública no Paquistão. Programas eficazes de controle da transferência de doenças parasitárias e seus fatores associados são recomendados.

Food handlers: an important reservoir of protozoans and helminth parasites of public health importance / Manipuladores de alimentos: um importante reservatório de protozoários e helmintos parasitas de importância para a saúde pública

Food handlers plays a primary role in the transmission of pathogenically important protozoans and helminth parasites. This study was aimed to evaluate the prevalence of intestinal pathogenic protozoans and helminth parasites among food handlers in and around University of Malakand, Lower Dir, Pakistan. Stool samples were collected from 642 food handlers (all of male) in a cross-sectional study from January to November, 2017. Wet Mount Techniques and concentration methods by using salt and formol–ether solutions. Three hundred and eighty four cases (59.8%) were found infected with one more parasites. Most of the individuals were found infected with helminth (47.6%) as compared to intestinal protozoans (0.93%). Seventy two cases (11.2%) of the cases presented mixed infection with both intestinal protozoan and helminth parasites. The order of prevalence for intestinal helminth was Ancylostoma duodenale (n = 258, 40.1%), followed by Taeniasa ginata (n=96, 14.9%) Ascaris lumbricoides (n = 54, 8.40%) and Trichuris trichura (n=30, 4.60%). For intestinal protozoa, Entamoeba histolytica/dispar (n = 36, 5.64%) was the only protozoan detected. Mono-parasitism was higher than poly-parasitism. Family size income and education level were the factors significantly (P<0.05) associated in the parasites prevalence. Current research showed that IPIs are primarily the foodborne pathogens still an important public health problem in Pakistan. Effective control programs on parasitic diseases transfer and their associated factors are recommended.

Os manipuladores de alimentos desempenham um papel fundamental na transmissão de protozoários e helmintos parasitas patogenicamente importantes. Este estudo teve como objetivo avaliar a prevalência de protozoários patogênicos intestinais e helmintos parasitas entre manipuladores de alimentos na Universidade de Malakand, Lower Dir, Paquistão. Amostras de fezes foram coletadas de 642 manipuladores de alimentos (todos do sexo masculino) em um estudo transversal de janeiro a novembro de 2017. Técnicas de montagem úmida e métodos de concentração usando soluções de sal e formol-éter. Trezentos e oitenta e quatro casos (59,8%) foram encontrados infectados com mais um parasita. A maioria dos indivíduos foi encontrada infectada por helmintos (47,6%) em comparação com protozoários intestinais (0,93%). Setenta e dois casos (11,2%) dos casos apresentavam infecção mista com protozoários intestinais e helmintos parasitas. A ordem de prevalência de helmintos intestinais foi Ancylostoma duodenale (n = 258, 40,1%), seguido por Taeniasa ginata (n = 96, 14,9%) Ascaris lumbricoides (n = 54, 8,40%) e Trichuris trichura (n = 30, 4,60 %). Para protozoários intestinais, Entamoeba histolytica / dispar (n = 36, 5,64%) foi o único protozoário detectado. Monoparasitismo foi maior do que poliparasitismo. A renda familiar e o nível de escolaridade foram os fatores significativamente (P <0,05) associados na prevalência de parasitos. A pesquisa atual mostrou que os IPIs são principalmente os patógenos de origem alimentar, ainda um importante problema de saúde pública no Paquistão. Programas eficazes de controle da transferência de doenças parasitárias e seus fatores associados são recomendados.

Food handlers: an important reservoir of protozoans and helminth parasites of public health importance

Abstract Food handlers plays a primary role in the transmission of pathogenically important protozoans and helminth parasites. This study was aimed to evaluate the prevalence of intestinal pathogenic protozoans and helminth parasites among food handlers in and around University of Malakand, Lower Dir, Pakistan. Stool samples were collected from 642 food handlers (all of male) in a cross-sectional study from January to November, 2017. Wet Mount Techniques and concentration methods by using salt and formolether solutions. Three hundred and eighty four cases (59.8%) were found infected with one more parasites. Most of the individuals were found infected with helminth (47.6%) as compared to intestinal protozoans (0.93%). Seventy two cases (11.2%) of the cases presented mixed infection with both intestinal protozoan and helminth parasites. The order of prevalence for intestinal helminth was Ancylostoma duodenale (n = 258, 40.1%), followed by Taeniasa ginata (n=96, 14.9%) Ascaris lumbricoides (n = 54, 8.40%) and Trichuris trichura (n=30, 4.60%). For intestinal protozoa, Entamoeba histolytica/dispar (n = 36, 5.64%) was the only protozoan detected. Mono-parasitism was higher than poly-parasitism. Family size income and education level were the factors significantly (P 0.05) associated in the parasites prevalence. Current research showed that IPIs are primarily the foodborne pathogens still an important public health problem in Pakistan. Effective control programs on parasitic diseases transfer and their associated factors are recommended.

Resumo Os manipuladores de alimentos desempenham um papel fundamental na transmissão de protozoários e helmintos parasitas patogenicamente importantes. Este estudo teve como objetivo avaliar a prevalência de protozoários patogênicos intestinais e helmintos parasitas entre manipuladores de alimentos na Universidade de Malakand, Lower Dir, Paquistão. Amostras de fezes foram coletadas de 642 manipuladores de alimentos (todos do sexo masculino) em um estudo transversal de janeiro a novembro de 2017. Técnicas de montagem úmida e métodos de concentração usando soluções de sal e formol-éter. Trezentos e oitenta e quatro casos (59,8%) foram encontrados infectados com mais um parasita. A maioria dos indivíduos foi encontrada infectada por helmintos (47,6%) em comparação com protozoários intestinais (0,93%). Setenta e dois casos (11,2%) dos casos apresentavam infecção mista com protozoários intestinais e helmintos parasitas. A ordem de prevalência de helmintos intestinais foi Ancylostoma duodenale (n = 258, 40,1%), seguido por Taeniasa ginata (n = 96, 14,9%) Ascaris lumbricoides (n = 54, 8,40%) e Trichuris trichura (n = 30, 4,60 %). Para protozoários intestinais, Entamoeba histolytica / dispar (n = 36, 5,64%) foi o único protozoário detectado. Monoparasitismo foi maior do que poliparasitismo. A renda familiar e o nível de escolaridade foram os fatores significativamente (P 0,05) associados na prevalência de parasitos. A pesquisa atual mostrou que os IPIs são principalmente os patógenos de origem alimentar, ainda um importante problema de saúde pública no Paquistão. Programas eficazes de controle da transferência de doenças parasitárias e seus fatores associados são recomendados.

Enzyme-based targeted disintegration of biofilms formed by food-borne pathogens: a review / 生物工程学报

Food-borne pathogens pose great risks to human health and public safety, and the formation of biofilm exacerbates their pathogenicity and antimicrobial resistance. Enzymes can target special substances in the biofilm to disintegrate the biofilm of food-borne pathogens, which has great potential for applications. This review summarized the progress of using enzymes to disintegrate the biofilms of food-borne pathogens, highlighting quorum-quenching enzymes, C-di-GMP metabolic enzymes, as well as extracellular matrix hydrolases. Finally, challenges and perspectives on developing enzymes into effective products for disintegrating the biofilms of food-borne pathogens were discussed.

Phenotypic and molecular characterization of erythromycin resistance in Campylobacter jejuni and Campylobacter coli strains isolated from swine and broiler chickens / Caracterização fenotípica e molecular da resistência à eritromicina em cepas de Campylobacter jejuni e Campylobacter coli isoladas de suínos e frangos de corte

Campylobacter spp. is a bacterial agent that causes gastroenteritis in humans and may trigger Guillain-Barré Syndrome (GBS) and is also considered one of the main foodborne diseases in developed countries. Poultry and pigs are considered reservoirs of these microorganisms, as well as raw or undercooked by-products are often incriminated as a source of human infection. Treatment in human cases is with macrolide, such erythromycin, that inhibits the protein synthesis of the microorganism. This study aimed to isolate Campylobacter jejuni and Campylobacter coli from intestinal content samples of broiler chickens (n=20) and swine (n=30) to characterize the erythromycin resistance profile of the strains and to detect molecular mechanisms involved in this resistance. The minimum inhibitory concentration was determined by agar dilution. The Mismatch Amplification Mutation Assay-Polymerase Chain Reaction (MAMA-PCR) was performed to detect mutations at positions 2074 and 2075 of 23S rRNA region, in addition to PCR test to detect the erm(B) gene. From the intestinal content of broiler chickens, 18 strains of C. jejuni and two strains of C. coli were isolated, whereas, from swine samples, no C. jejuni strain and 14 strains of C. coli were isolated. All C. coli strains were resistant, and three C. jejuni strains from broilers chickens were characterized with intermediate resistance to erythromycin. The MIC of the strains ranged from ≤0.5mg/μL to ≥128mg/μL. All resistant strains had the A2075G mutation, and one strain with intermediate resistance had the A2075G mutation. However, the A2074C mutation and the erm(B) gene were not detected. High resistance levels were detected in C. coli strains isolated from swine. The MAMA-PCR is a practical tool for detecting the erythromycin resistance in Campylobacter strains.(AU)

Campylobacter spp. é um agente bacteriano causador de gastroenterite em humanos e associado à síndrome de Guillain-Barré, sendo a campilobacteriose considerada uma das principais enfermidades de origem alimentar. Aves e suínos são importantes reservatórios desses microrganismos e seus produtos derivados crus ou mal cozidos são muitas vezes incriminados como fonte de infecção humana. A primeira escolha para o tratamento em casos humanos são os antimicrobianos da classe dos macrolídeos como à eritromicina. Dentro desse contexto, o objetivo deste estudo foi isolar Campylobacter jejuni e C. coli a partir de 20 amostras de conteúdo intestinal de frangos de corte e de 30 de suínos ao abate e investigar a resistência à eritromicina das estirpes obtidas e os possíveis mecanismos moleculares envolvidos nesta resistência. A concentração inibitória mínima foi determinada pela diluição em ágar e a técnica MAMA-PCR foi utilizada para detecção de mutações nas posições 2074 e 2075 da região 23s rRNA, foi pesquisado também a presença do gene erm(B) pela PCR. A partir do conteúdo intestinal de frangos de corte foram isoladas 18 estirpes de C. jejuni e duas de C. coli, enquanto de suínos foram obtidas 14 estirpes de C. coli e nenhuma estirpe de C. jejuni. Todas as estirpes de C. coli de suínos foram identificadas como resistentes e três estirpes de C. jejuni de frangos foram caracterizadas com resistência intermediária. A CIM das estirpes variou de ≤0,5mg/μL a ≥128mg/μL. Todas as estirpes resistentes tinham a mutação A2075G e uma cepa com resistência intermediária também apresentou a mutação A2075G. Não foi detectada a mutação A2074C ou a presença do gene erm(B) em nenhuma das estirpes obtidas. Os resultados revelam um alto nível de resistência em estirpes de C. coli isoladas de suínos frente a eritromicina. A técnica MAMA PCR utilizada se constitui em uma ferramenta prática para detecção da resistência à eritromicina em estirpes de C. jejuni e C. coli.(AU)

Influence of lipids and proteins amounts and pH values on the inhibitory effects of Origanum vulgare L. essential oil against Escherichia coli and Salmonella Typhimurium

Origanum vulgare L. (OVEO) essential oil has been considered a candidate antimicrobial for use in food conservation systems. However, studies on the influence of concomitant variations of different food components or physicochemical parameters on the antibacterial properties of OVEO are scarce. This study assessed the influence of concomitant variations in amounts of proteins - PTN (4.0, 6.0 or 8.0 g/100 mL) and lipids - LIP (3.75, 5.0 or 6.25 g/100 mL) and pH values (5.0, 5.5 or 6.0) in cultivation medium on the inhibitory effects of OVEO against Escherichia coli (EC) and Salmonella Typhimurium (ST). Lowest minimum inhibitory concentration values of OVEO against EC and ST were observed in media with the highest LIP amounts regardless the PTN amount and pH value. In absorbance based microtiter plate assay (MPA), for both EC and ST, OVEO caused the lowest Grmax values in medium containing the highest LIP and PTN amounts and lowest pH value. Highest Grmax values for EC and ST were observed in medium containing the lowest LIP and PTN amount and highest pH value. Grmax values estimated from viable counts of EC and ST in tested media with OVEO confirmed bacterial growth behavior similar to that observed in MPA. Overall, the LIP amount in media was as the most influential factor to enhance the antibacterial effects of OVEO. These results indicate that the concomitant influence of LIP and PTN amounts and pH values on the antibacterial effects of OVEO should be considered for optimizing its antimicrobial efficacy in foods.

Emerging drug resistant pathogens from food animals: Balancing food security and safety in developing countries

@#Drugs are used essentially to treat illnesses in humans and animals. When metabolized in food animals, they are harmless, but residues may remain in tissues, meat and milk that can present risks in the food chain. A longterm consequence of drug residues in food of animal origin is the development and emergence of antimicrobial resistance (AMR). Generally, increasing the use of antimicrobials in medical and veterinary practice exacerbates AMR. Spread of infection or resistant pathogen or resistance genes in the environment can be explained by the close link between humans, animals, and the environment. The public health and economic impact of AMR have been estimated to be around 100 trillion US dollars each year and food animals are a major reservoir of AMR microorganisms in many low and middle income countries (LMIC). However,due to the lack of data on food-borne pathogens and antimicrobial usage is a challenge in the control of AMR in LMICs where the food industry is heterogeneous, largely informal, and unregulated. Emergence and transmission of AMR in developing countries are linked to food of animal origins, but the awareness of this relationship is low. Overall, the challenge of food insufficiency also described as food insecurity and a lack of adequate food safety measures can worsen the incidence and persistence of AMR. This review summarizes the issues and challenges of emerging drug resistant pathogens from food animals in developing countries, and highlights the importance of a holistic perspective in addressing AMR in humans in the context of the One Health approach.

Strain variability of foodborne pathogens in microbiological risk assessment - a review / 生物工程学报

Strain variability is one of the most important factors to influence the accuracy of foodborne pathogens risk assessment, such as Listeria monocytogenes, Salmonella spp. Strain-to-strain variation is defined as the inherent differences among identically treated strains of the same microbial species. The differences cannot be eliminated by changing test methods or improving test protocols. This review addresses presently related studies of strain variability. Based on the effect of strain variability on the outcome of risk assessment, we summarize sources of variabilities in food chain, strain phenotypic variabilities and the methods to integrate strain variability in growth and inactivation into predictive modelling, and indicate the inadequacies in the study of strain variability. We suggest further study the mechanism of strain variability, expand the comparison of variability among different sources, and integrate the variability of gene expression, protein and cell metabolism into the predictive modelling.

Evaluation of different samples pretreatment method of MALDI-TOF MS on the identification of common foodborne pathogens / 上海预防医学

Objective To evaluate the effects of different sample pretreatment methods of MALDI-TOF MS on the identification of common foodborne pathogens. Methods A total of 51 common foodborne pathogens were collected, covering Salmonella, Staphylococcus, Listeria, Vibrio, Escherichia, and Shigella.Then the effects of three sample treatment methods including direct smear method, in-situ formic acid extraction method and formic acid acetonitrile extraction method of MALDI-TOF MS on the identification of common foodborne pathogens were evaluated. Results There were no significant differences in the identification results of Salmonella, Shigella, and Escherichia by three sample pretreatment methods; Staphylococcus captis, Staphylococcus cohnii, Vibrio parahaemolyticus and Vibrio vulnificus could not be identified effectively by direct smear method, but these strains could be accurately identified by other methods.Non-listeria monocytogenes strains of listeria genus were often mistakenly identified by using direct smear method and in-situ formic acid extraction method, and the use of formic acid and acetonitrile extraction could improve the identification accuracy for different species of listeria. Conclusion Different sample pretreatment methods of MALDI-TOF MS have certain influence on the identification of common foodborne pathogenic bacteria.Therefore, selecting appropriate sample pretreatment methods is important to obtain reliable and accurate identification results.

Avaliação microbiológica de queijos minas artesanais provenientes da Serra da Canastra durante e após o período de maturação / Microbiological evaluation of artisanal minas cheeses from Serra da Canastra during and after the ripening period

O queijo minas artesanal da Canastra é produzido na região da Serra da Canastra por pequenos produtores, sendo que alguns são cadastrados no Programa Queijo Minas Artesanal (PQMA) do Instituto Mineiro de Agropecuária (IMA). Por ser fabricado com leite cru, é importante que os patógenos que podem ser veiculados sejam controlados durante e após o período mínimo de maturação do queijo de 22 dias. Este trabalho avaliou as características microbiológicas de queijos obtidos de 78 produtores rurais da região da Canastra após a maturação e de três produtores rurais durante maturação. As contagens de coliformes totais, Escherichia coli e Staphylococcus coagulase positiva foram realizadas em placas Petrifilm® (3M). A detecção de Salmonella spp. foi realizada utilizando o método ISO 6579: 2002 e por PCR convencional e Listeria monocytogenes foi investigada de acordo com o método ISO 11290-1:1996/(A) 1: 2004 e PCR convencional. A contagem de Enterobacteriaceae foi determinada pelo método APHA 9.62: 2015. As mensurações de pH foram realizadas de acordo com o método IAL 017/IV em pHmetro digital BEL engineering e aferidas diretamente com pHmetro Hanna Instruments e a atividade de água (aw) em analisador Aqua Lab. No estudo realizado ao longo da maturação, as análises indicaram que as amostras, todas provenientes de produtores cadastrados no PQMA, atingiram os limites estabelecidos pela legislação antes dos 22 dias de maturação. Houve diferença significativa (p<0,05) no pH das amostras ao longo da maturação, embora este parâmetro não tenha correlação com as contagens analisadas. Já no estudo pós maturação, os resultados mostraram que 54% das amostras dos produtores cadastradas e 65% das amostras dos produtores não cadastradas no PQMA não atenderam a pelo menos um parâmetro microbiológico exigido pela legislação. As contagens obtidas para Enterobacteriaceae variaram de <1 a 6,6 log UFC/g, para coliformes totais de <1 a 6,4 log UFC/g, E. coli de <1 a 5,8 log UFC/g e Staphylococcus coagulase positiva de <1 a 7,6 log UFC/g. Em nenhuma amostra foi encontrada Salmonella spp e L. monocytogenes foi detectada e confirmada por PCR em uma amostra analisada. Os valores obtidos de pH e aw estratificados em grupos que atendem e não atendem a legislação não mostraram diferença significativa, sugerindo que esses parâmetros não são bons indicadores de qualidade microbiológica do produto. O elevado número de não-conformidades indica que são necessários esforços para melhoria das condições higiênico-sanitárias refletidas por meio dos indicadores microbiológicos. O registro no PQMA mostrou-se efetivo durante o estudo da maturação, mas não teve o mesmo resultado no estudo mais abrangente realizado pós maturação. São necessários mais esforços dos produtores (cadastrados e não cadastrados) bem como dos órgãos reguladores para melhoria dos indicadores microbiológicos

Canastra artisanal minas cheese is produced in the Serra da Canastra region by small farmers who may or may not be registered in the Artisanal Minas Cheese Program (PQMA) of the Agricultural Institute of Minas Gerais (IMA). Since this cheese is made from raw milk, it is important that the pathogens that may be carried in this product are controlled during the 22 days of ripening. This work evaluated the microbiological characteristics of cheese samples from 78 rural properties in the Canastra region after the ripening period and during ripening in three rural properties. Total coliform counts, Escherichia coli and Staphylococcus coagulase positive were performed on Petrifilm® plates (3M). The detection of Salmonella spp. was performed using the ISO 6579: 2002 method and conventional PCR and Listeria monocytogenes was investigated according to ISO 11290-1: 1996/(A) 1: 2004 and conventional PCR. The Enterobacteriaceae count was determined by the APHA method 9.62: 2015. The pH analyzes were performed according to the IAL 017/IV method on a BEL engineering digital pHmeter and measuring directly with Hanna Instruments pHmeter and the water activity (aw) in Aqua Lab analyzer. In the study carried out during ripening, the analyzes indicated that the samples, all from properties registered in the PQMA, reached the limits established by the legislation before the 22 days of ripening. There was a significant difference (p <0.05) in the pH of the samples during ripening, even though this parameter did no correlate with the microbiological counts. In the post-ripening study, the results showed that 54% of samples from PQMA registered properties and 65% of samples from non-registered properties did not comply with at least one microbiological parameter required by the legislation. Enterobacteriaceae counts ranged from <1 to 6.6 log CFU/g, for total coliforms from <1 to 6.4 log CFU/g, E. coli from <1 to 5.8 log CFU/g and Staphylococcus coagulase positive from <1 to 7.6 log CFU/g. Salmonella spp was not detected and L. monocytogenes was detected and confirmed by conventional methodology and by PCR in one analyzed sample. The pH and aw values stratified in groups that complied and did not comply with the legislation showed no significant difference, suggesting that these parameters are not good indicators of microbiological safety of the product. The high number of nonconformities indicates that efforts are needed to improve the hygiene and sanitary conditions reflected through the microbiological indicators. The PQMA registration was effective during the ripening study but did not have the same result in the larger post-ripening study. More efforts are needed from producers (registered and non-registered) as well as regulators to improve microbiological indicators of this cheese

Antimicrobial efficacy of fermented mango leaves beverage towards selected foodborne pathogens

Aims@#Fermented mango leaves of Chokanan variety was produced using selected symbiotic culture of bacteria and yeast (SCOBY) from MARDI’s Collection of Functional Food Cultures (CFFC). The aim of this work was to investigate its functional benefits as food remedy to reduce the risk of food poisoning illness incidence. @*Methodology and results@#Five species of foodborne pathogens: Escherichia coli O157:H7 UPMEC32 (local isolate), Salmonella typhimurium ATCC®53648™, Salmonella enteritidis MDC15 (local isolate), Listeria monocytogenes ATCC®51772™ and Streptococcus gallolyticus (ATCC®9809™) were selected to examine the antimicrobial effect of fermented mango leaves beverage by means of agar well diffusion assay and broth microdilution method to determine its minimum bactericidal concentration (MBC>99). In comparison with chemical inhibitor (acetic acid, 1%) and antibiotic (Penicillin streptomycin, 1%), the agar diffusion assay results confirmed the inhibition efficacy of fermented mango leaves beverage against all five foodborne pathogens tested. Particularly, fermented mango leaves beverage was showing a significant inhibitory effect (P<0.05) against S. gallolyticus, whereas both acetic acid and penicillin streptomycin have no inhibitory activities at all towards this pathogen. Another antimicrobial activity assay using broth microdilution method also confirmed the 100% inhibition effect of fermented mango leaves beverage against these selected pathogenic microorganisms. Furthermore, the efficacy retained 100% inhibitory activities even though the fermented mango leaves beverage has been diluted to 50%. Synergetic effect of significant amount of multiple organic acids present in fermented mango leaves beverage were the main factors contributing to its potent antimicrobial properties and improvement taste after fermentation. On the contrary, little or no antimicrobial inhibitory activity was observed in all non-fermented mango leaves beverages treated samples. @*Conclusion, significance and impact of study@#This finding indicates that the potential of fermented mango leaves beverages as prophylaxis measures to reduce the risk of food poisoning incidence as it has shown a good antimicrobial effect against selected foodborne pathogens. Moreover, this fermented mango leaves beverage are more tasteful after gone through the microbial fermentation process. It is recommended to consume daily to reduce the incidence of food poisoning illness.

Control de crecimiento de Listeria monocytogenes en co-cultivo con Lactobacillus plantaram / Growth control of Listeria monocytogenes in co-culture with Lactobacillus plantarum

RESUMEN Listeria monocytogenes (Lm) es un patógeno emergente causante de enfermedades transmitidas por alimentos de consumo masivo principalmente cárnicos y lácteos. Actualmente se buscan diferentes estrategias para su control, entre ellas compuestos naturales producidos por otros microorganismos como ácidos orgánicos y otros compuestos como lactoferrina, lisozima y bacteriocinas, estas últimas producidas por especies de bacterias como Lactobacillus plantarum (Lp). El objetivo de esta investigación fue determinar el efecto de cepas de Lp aisladas de suero costeño sobre el control de crecimiento de L. monocytogenes inoculada en co-cultivos. Se realizaron curvas de crecimiento para Lm, Lp 60-1 y Lp 62-1 y co-cultivos de cada Lp con Lm. La cinética de crecimiento fue evaluada determinando la viabilidad durante 24h en agares selectivos. La tasa de crecimiento de L. monocytogenes inoculada como control en leche UHT y en co-cultivos, presentaron diferencias significativas (p<0,05) entre los tratamientos, evidenciando que el control alcanzó un valor promedio de tasa de crecimiento mayor (µmax =0,65 h-1), que el obtenido para los co-cultivos con Lp 60-1 y Lp 62-1 (µmax =0,22 h-1 y µmax =0,27 h-1 respectivamente). La mayor diferencia fue alcanzada en el co cultivo con Lp 60-1, obteniendo el menor valor promedio de tasa de crecimiento de Lm. Los resultados demuestran la eficiencia de las cepas de Lp (60-1 y 62-1) para el control de crecimiento de Lm en leche UHT comercial, siendo esta una alternativa para reducir el uso de aditivos químicos durante la producción de lácteos.

ABSTRACT Listeria monocytogenes (Lm) is an emerging pathogen causing foodborne diseases especially in dairy products and meat. Nowadays are sought different strategies to their control for example natural compounds produced by microorganisms, such as organic acids and other compounds as lactoferrin, lysozyme and bacteriocins, the latter produced by bacterial species as Lactobacillus plantarum (Lp). The main objective of this research was to determine the effect of Lp strains isolated from "Suero costeño" inoculated in co-culture over the L. monocytogenes growth. There where made growth kinetics for Lm, Lp 60-1 and Lp 62-1 and co-cultures of each Lp with Lm. The growth kinetic was evaluated establishing the viability during 24h in selective culture media. The growth rate of L. monocytogenes inoculated in UHT milk and in co-culture, showed a significative difference (p<0,05) between the treatments, demonstrating that the control reach an average value of growth rate higher (µmax =0,65 h-1) than the one obtained for the co-culture with Lp 60-1 and Lp 62-1 (µmax =0,22 h-1 and µmax =0,27 h-1 respectively). The higher difference between the last two treatments was given by the treatment with Lp 60-1, obtaining the lowest average value for the Lm growth. The results showed the efficiency of the Lp strains (60-1 y 62-1) for the growth control of Lm in UHT commercial milk, being an alternative to reduce the use of chemical additives during the production of dairy products.

Combined effects of garlic essential oil and allyl isothiocyanate against Escherichia coli O157:H7 in vitro and in pork sausage / Efeito combinado de óleo essencial de alho e isotiocianato de alila contra Escherichia coliO157:H7 in vitro e em linguiça suína

ABSTRACT: Escherichia coli O157:H7 is a toxigenic serotype of E. coli and has been associated with foodborne outbreaks involving meat products, vegetables and fresh produces worldwide. Salts for curing are usually employed as antimicrobials in the production of pork sausages. However, salts do not have a significant inhibitory effect on enterobacteria. Due to the growing demand for natural foods, the use of essential oils has been proposed as natural antimicrobials in food. This study aimed to evaluate the effects of garlic essential oil (GO) and allyl isothiocyanate (AITC) against E. coli O157:H7 in vitro and in pork sausage. The Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) of these oils, alone and in combination, against E. coli O157:H7 were determined. Pork sausage was inoculated with 8log CFU/g E. coli O157:H7 and different combinations of GO and AITC. A control group was performed without essential oils. Sausages were packaged and stored at 6°C for 20 days. E. coli O157:H7 population and instrumental color (L*, a*, b*, C* and hue) determinations were performed at 5-day intervals. AITC showed lower MIC and MBC than GO. When combined, AITC and GO showed a synergistic effect. Treatments T3 and T4 showed 1,01log CFU and 1,87log CFU reduction of E. coli O157:H7 compared to control. The redness and the chroma of sausages treated with AITC and GO increased during storage. Together, GO and AITC caused minor changes in taste and flavor of sausages, and were able to reduce the population of E. coli O157:H7 and to maintain the red color of sausage during storage.

RESUMO: Escherichia coli O157:H7 é um sorotipo toxigênico de E. coli associado mundialmente a surtos de doenças alimentares causadas por produtos cárneos. Os sais de cura são normalmente empregados como antimicrobianos na fabricação de linguiças, entretanto, possuem pouco efeito inibitório sobre enterobactérias como E. coli. Devido à crescente demanda por produtos naturais, o uso de óleos essenciais tem sido proposto como antimicrobiano natural em alimentos. O objetivo deste estudo foi avaliar os efeitos do óleo essencial de alho (GO) e isotiocianato de alila (AITC) contra E. coli O157:H7 in vitro e em linguiça. As concentrações inibitória mínima (MIC) e bactericida mínima (MBC) dos óleos, isolados e em combinação, contra E. coli O157:H7 foram determinadas in vitro. Lotes de linguiça foram inoculados com 8log UFC/g E. coli O157:H7 e diferentes concentrações de GO + AITC e estocados a 6°C por 20 dias. Contagens de E. coli O157:H7 e determinação de cor instrumental (L*, a*, b*, C* e hue) foram realizadas a cada 5 dias. Nos testes in vitro, AITC mostrou maior ação inibitória que GO, havendo efeito sinérgico dos óleos quando combinados. Os tratamentos T3 e T4 mostraram redução de 1,01log UFC e 1,87log UFC de E. coli O157:H7 comparados ao controle. A intensidade de cor vermelha e a saturação de cor aumentaram durante a estocagem nas linguiças adicionadas de óleos essenciais. A adição dos óleos GO + AITC causou mínima alteração no sabor e na aparência das linguiças e foi capaz de reduzir a população de E. coli O157:H7 no produto cárneo, mostrando potencial para uso como conservante natural nesse tipo de alimento.

Antimicrobial effect of copper surfaces on bacteria isolated from poultry meat

Abstract Poultry meat is a food product that usually carries high rates of microbial contamination, including foodborne pathogens. The poultry industry has established different systems to minimize these hazards. In recent years, extensive literature has demonstrated the antimicrobial activity of different contact surfaces made of copper to effectively reduce microbial loads. The aim of the present study was to evaluate the antibacterial effect of copper surfaces on the transmission of two foodborne pathogens - Salmonella enterica and Listeria monocytogenes - and a poultry native microbiota bacterial species - Enterobacter cloacae. We also evaluated the impact of the poultry meat matrix on the antimicrobial activity of a copper surface. Our results indicated that copper surfaces reduced the bacterial load quickly (<than 4 min) when the microorganisms were exposed to polished copper surfaces. Even when bacteria were inoculated on copper surfaces soiled with the organic matrix (washing water from poultry carcasses) and survival rates were significantly higher, an antimicrobial effect was still observed. Survival rates of two microorganisms simultaneously exposed to copper did not show significant differences. We found an antimicrobial effect over pathogenic and non-pathogenic microorganisms. Results suggest a potential role for copper surfaces in the control of microbiological hazards in the poultry industry.

Antimicrobial effect of copper surfaces on bacteria isolated from poultry meat

Abstract Poultry meat is a food product that usually carries high rates of microbial contamination, including foodborne pathogens. The poultry industry has established different systems to minimize these hazards. In recent years, extensive literature has demonstrated the antimicrobial activity of different contact surfaces made of copper to effectively reduce microbial loads. The aim of the present study was to evaluate the antibacterial effect of copper surfaces on the transmission of two foodborne pathogens Salmonella enterica and Listeria monocytogenes and a poultry native microbiota bacterial species Enterobacter cloacae. We also evaluated the impact of the poultry meat matrix on the antimicrobial activity of a copper surface. Our results indicated that copper surfaces reduced the bacterial load quickly ( than 4 min) when the microorganisms were exposed to polished copper surfaces. Even when bacteria were inoculated on copper surfaces soiled with the organic matrix (washing water from poultry carcasses) and survival rates were significantly higher, an antimicrobial effect was still observed. Survival rates of two microorganisms simultaneously exposed to copper did not show significant differences. We found an antimicrobial effect over pathogenic and non-pathogenic microorganisms. Results suggest a potential role for copper surfaces in the control of microbiological hazards in the poultry industry.

The structure characteristics of prophages of foodborne Enterococcus hirae R17 and their interaction relationships with host bacterium / 中国食品卫生杂志

Objective This study was to understand the structure characteristics of prophages in the genome of Enterococcus hirae R17,and also to analyze their interaction relationships with the host bacterium.Methods The gene distribution and gene encoding characteristics of prophages in the genome of Enterococcus hirae R17 were identified using the PHAST software.The virulence gene,antimicrobial resistance genes,and environmental resistance genes in the prophages were also analyzed.Results Three prophages were found on the chromosome of Enterococcus hirae,including two incomplete prophage elements (Prophage-1 and Prophage-2) and one complete prophage (Prophage-3).Some function genes of bacteria were found in the sequence of three prophages,including nucleotide transportation and metabolism related genes.One incomplete prophage carrying erythromycin-and bacitracin-resistance genes was identified in the plasmid,which suggested that prophage induced gene horizontal transfer caused erythromycin-and bacitracin-resistance of Enterococcus hirae R17.Conclusion This study laid a solid foundation for the diversity analysis of prophages of Enterococcus hirae.Prophages played an important role in promotion of antimicrobial resistance of enterococci.Scientists should pay more attention to the spread of antimicrobial resistance and pathogenicity induced by prophages.

The pathogenicity of 240 Vibrio parahaemolyticus serovar O3 strains / 中国食品卫生杂志

Objective To analyze the relationship between virulence genes and traditional Kanagawa phenomena,based on the virulence genes carried by Vibrio parahaemolyticus isolates from different sources of serovar O3,to provide basic data for further studies on the pathogenicity of Vibrio parahaemolyticus.Methods Multiplex polymerase chain reaction (PCR) and Kanagawa phenomenon assay were performed to detect the existence of virulence associated genes tdh and trh as well as haematolysis of Vibrio parahaemolyticus serovar O3 strains with different origin.The correlation between tdh and trh genes and Kanagawa phenomenon were verified based on test.Results Among 183 Vibrio parahaemolyticus serovar O3:K6 strains,tdh gene was detected in 182 strains and trh gene exists in the remaining strain,detection rate of the two genes were 99.45％ (182/183) and 0.55％ (1/183),respectively.The positive rate of Kanagawa phenomenon was 100.00％ (183/183).Among 57 Vibrio parahaemolyticus serovar O3 non-K6 strains,detection rate of tdh gene was 3.51％ (2/57),trh gene was not detected.Furthermore,the positive rate of Kanagawa phenomenon was 10.53％ (6/57).Significant correlation between tdh gene and Kanagawa phenomenon was verified (x2=1.78,P ＞ 0.05),meanwhile,similar between trh gene and Kanagawa phenomenon was not detected (x2 =186.01,P ＜0.05).Conclusion Significant correlation between tdh gene and Kanagawa phenomenon was verified in Vibrio parahaemolyticus serovar O3:K6 strains,and pathogenicity of Vibrio parahaemolyticus can be detected by using PCR method rapidly.

Analysis of the characteristics of Salmonella enteritidis virulence genes from different origins / 中国食品卫生杂志

Objective To investigate the differences and characteristics of virulence genes carried by Salmonella enteritidis from different sources in Shijiazhuang City.Methods One hundred and twenty-four strains of Salmonella enteritidis isolated from morning markets of raw and poultry stalls,slaughterhouses and food poisoning specimens in Shijiazhuang area were collected.Eight virulence genes (invA,sopE,agfA,spvR,hilA,stn,pefA,shdA) were detected by polymerase chain reaction (PCR).Results Salmonella enteritidis might have different virulence gene profiles.The above eight virulence genes were detected in different strains.The carrying rate of virulence genes invA,sopE,stn,hilA,spvR and pefA in the food poisoning strains was higher than 94％.There was no difference in the carrying rate of 8 virulence gene between the morning raw poultry stalls isolates and the patient strains,but was different with the slaughterhouse strains.Conclusion There were more risks of food poisoning caused by Salmonella enteritidis from morning markets,and the hygiene supervision should be strengthened to prevent and control foodborne disease.

Microbial Quality and Antibiotic Residues in Raw Beef from Selected Abattoirs in Accra, Ghana.

Aims: To determine the microbial quality and the presence of antibiotic residues in raw beef from four major abattoirs in Accra, Ghana. Study Design: Cross sectional. Place and Duration of Study: Samples were obtained from the four major abattoirs namely; Madina, Tema (GIHOC), Accra, Amasaman and the University of Ghana (UG) Farms, transferred immediately to the Bacteriology Laboratory, Noguchi Memorial Institute for Medical Research, University of Ghana, for processing. The study was carried out between June 2013 and April, 2014. Methodology: Raw beef samples were aseptically collected from 200 cattle slaughtered for consumption. Total plate count, presence of foodborne pathogens such as Listeria monocytogenes, Escherichia coli, E. coli 0157:H7, Staphylococcus aureus, Salmonella and Shigella species were determined after culture and incubation on standard microbiological media. Both liver and kidney samples were also collected from each of the 200 carcasses and tested for antibiotic residues using Premi® test kit (R-Biopharm AG, Germany). Results: The total plate counts in all the samples from the abattoirs ranged between 8.3x103 – 5.5x105 cfu/g. A total of 43 pathogens were isolated. Of this number, 30 (69.76%) were E. coli, 8 (18.69%) S. aureus, 2 (4.65%) Salmonella Typhimurium, 2 (4.65%) L. monocytogenes and 1 (2.3%) Yersinia enterocolitica. Fifty-nine strains from other species were also isolated: Bacillus spp. (21), Enterobacter spp. (18), Pseudomonas aeruginosa (1), Aeromonas spp. (3), coliforms (12) and Klebsiella spp. (4). None of the E. coli isolated were positive for O157: H7. Overall, 18% of both the liver and kidney samples were positive for the presence of antibiotic residues but the kidneys recorded the highest (12%) percentage of positive whilst the liver recorded (6%). Conclusion: Beef at the abattoirs were contaminated with foodborne pathogens and antibiotic residues, however, the total aerobic counts were within the acceptable range considered safe for human consumption. Detection of pathogens and antibiotic residues in beef is of public health concern.

Comparative study of different methods for detecting foodborne pathogens / 国际检验医学杂志

Objective To investigate the feasibility of the gene chip technique and multiplex PCR technique for detecting and screening foodborne pathogens .Methods The primer sequences were designed to target cells ,the biotin was adopted to label the re‐verse primer 5′end and the amino group was adopted to label oligonucleotide probe 5′end .The probe spotted on a solid support for preparing microarray ,PCR product was hybridized with microarray probe region ,PCR and hybridization reaction system was opti‐mized .Results The microarray technique could simultaneously detect multiple pathogens of Shigella ,Salmonella ,Klebsiella pneu‐moniae ,Brucella ,Proteus mirabilis ,Staphylococcus aureus ,Campylobacter jejuni ,etc .,which was easy to operate and had strong specificity .The sensitivity of bacterial pure cultures was 5 .0 × 102 CFU/mL ,the sensitivity of DNA detection was 0 .1 pg ,the coin‐cidence rate for detecting isolated bacteria was 100 % .The PCR detection system was established and optimized by using primers , the concentration of Mg2+ and the annealing temperature Tm value of 1 .5 mmol/L and 56 ℃ were determined ,the detection sensi‐tivity reached to 10 pg ,all the specific primers amplified bands could be amplified under this sensitivity .Conclusion The gene chip technique and multiplex PCR technique can effectively detect foodborne pathogens ,which provide a new idea for detecting pathogens with the high‐throughput screening and are worth popularization and application in the field of food safety .