Principles and applications of hyperspectral imaging in quality evaluation of agro-food products: a review.

The requirements of reliability, expeditiousness, accuracy, consistency, and simplicity for quality assessment of food products encouraged the development of non-destructive technologies to meet the demands of consumers to obtain superior food qualities. Hyperspectral imaging is one of the most promising techniques currently investigated for quality evaluation purposes in numerous sorts of applications. The main advantage of the hyperspectral imaging system is its aptitude to incorporate both spectroscopy and imaging techniques not only to make a direct assessment of different components simultaneously but also to locate the spatial distribution of such components in the tested products. Associated with multivariate analysis protocols, hyperspectral imaging shows a convinced attitude to be dominated in food authentication and analysis in future. The marvellous potential of the hyperspectral imaging technique as a non-destructive tool has driven the development of more sophisticated hyperspectral imaging systems in food applications. The aim of this review is to give detailed outlines about the theory and principles of hyperspectral imaging and to focus primarily on its applications in the field of quality evaluation of agro-food products as well as its future applicability in modern food industries and research.

Resistant enterococci isolated from raw sheep's milk and cheeses from South region of Brazil / Enterococos resistentes isolados de leite cru de ovelha e queijos da região Sul do Brasil

Enterococci have been used as sentinel organisms for monitoring antimicrobial resistance in food, humans, and other animals. In this sense, the present study evaluated the antimicrobial susceptibility profile and the presence of genes associated with resistance to erythromycin (msrC and ermB) and tetracycline [tet(M) and/or tet(L)] in enterococci isolated from raw sheep's milk and cheeses (colonial, feta-, and pecorino-type) from South region of Brazil. A total of 156 enterococci were isolated from milk (n=80) and cheese (n=76) samples, identified by MALDI-TOF. Enterococcus faecalis (50.6%; n=79) was the most frequent species isolated from both samples. According to in vitro susceptibility tests, enterococci strains were not susceptible to the most commonly antimicrobial agents used in human and veterinary medicine. The frequency of MDR strains in enterococci isolated from milk (53.7%) was higher than those from cheese (24.2%). The tet(M) gene was the most commonly detected among tetracycline not-susceptible strains. The present study provided the first evidence of antimicrobial not-susceptible enterococci in raw sheep's milk and cheeses in South Brazil. Drug-resistant strains, particularly those that are MDR, constitute a One Health issue.

Os enterococos têm sido usados como organismos sentinela para monitorar o padrão de suscetibilidade a antimicrobianos em alimentos, humanos e outros animais. Neste sentido, o presente estudo objetivou avaliar o perfil de susceptibilidade a antimicrobianos e os genes associados com a resistência a eritromicina (msrC and ermB) e à tetraciclina [tet(M) and/or tet(L)] em enterococos isolados de leite cru de ovelha e queijos (colonial, tipo-feta e tipo-pecorino) do Sul do Brasil. Um total de 156 enterococos foram isolados de leite (n=80) e queijo (n=76), identificados por MALDI-TOF. Enterococcus faecalis (50,6%; n=79) foi a espécie mais frequentemente isolada de ambas as amostras. De acordo com o teste de suscetibilidade in vitro, as cepas de enterococos não foram susceptíveis aos agentes antimicrobianos mais comumente utilizados na clínica humana e veterinária. A frequência de cepas de enterococos MDR isoladas do leite (53,7%) foi superior à do queijo (24,2%). O gene tet(M) foi o mais comumente detectado entre as cepas não susceptíveis à tetraciclina. O presente estudo fornece as primeiras evidências de enterococos não susceptíveis aos antimicrobianos em leite cru de ovelha e queijos no Sul do Brasil. Cepas resistentes a drogas, particularmente as que são MDR, representam uma preocupação de Saúde Única.

Bacterial communities in artisanal raw bovine milk cheeses from the southern region of Brazil / Comunidades bacterianas em queijos artesanais de leite bovino cru da região sul do Brasil

The production of artisanal cheeses made with raw bovine milk has grown in the southern region of Brazil. It is important to obtain information about the risks of this practice, especially concerning food safety. In this study, next-generation sequencing was used to identify and characterize the bacterial communities of artisanal raw milk cheeses. We analyzed one pool of five raw milk samples (control group M1) from different dairy farms and nine pools (M2-M10) of 45 artisanal raw milk cheeses.The characterization of the bacterial communities included 199 species distributed across 59 different genera dispersed among the samples. Among the genera observed, 11 were classified as beneficial to the aroma, flavour, colour, and texture of the cheese. Thirty-one genera were classified as harmful to these characteristics. Another 17 were classified as potential pathogens for animals and humans, including Aeromonas, Bacillus, Cronobacter, Salmonella, Staphylococcus, and bacteria of the coliform group, including E. coli and Klebsiella. There was a significant difference (P < 0.05) in the number of bacterial communities identified between the control group (M1) and the two pools of artisanal raw milk cheeses (M2 and M8). This study demonstrated that next-generation sequencing provides in-depth information on the composition of the microbiota in artisanal raw milk cheeses, characterizing bacterial communities, identifying the wide microbial diversity, and identifying microbial benefits and risks.

Devido ao aumento da produção de queijos artesanais com leite bovino cru na região sul do Brasil, é importante obter informações sobre os riscos desta prática, principalmente no que se refere à segurança do alimento. Neste estudo foi utilizada a técnica de Next Generation Sequencing (NGS) para identificar e caracterizar comunidades bacterianas de queijos artesanais de leite cru. Foram analisados um pool de cinco amostras de leite cru como grupo controle (M1) de diferentes propriedades leiteiras localizadas na região norte do estado do Rio Grande do Sul, e nove pools (M2-M10) de 45 queijos artesanais de leite cru. A caracterização das comunidades bacterianas incluiu 199 espécies distribuídas em 59 gêneros diferentes dispersos entre as amostras. Dentre os gêneros observados, 11 foram classificados como benéficos ao aroma, sabor, cor e textura do queijo, enquanto 31 gêneros foram classificados como prejudiciais a essas características. Outros 17 foram classificados como potenciais patogênicos para animais e humanos, incluindo Aeromonas, Bacillus, Cronobacter, Salmonella, Staphylococcus, bactérias do grupo coliforme como Escherichia coli e Klebsiella. Houve diferença significativa (P < 0,05) entre o número de comunidades bacterianas identificadas no grupo controle (M1) e dois pools de queijos artesanais de leite cru (M2 e M8). Este estudo demonstra que o NGS fornece informações detalhadas sobre a composição da microbiota em queijos artesanais de leite cru, caracterizando comunidades bacterianas, identificando a ampla diversidade microbiana, os benefícios e riscos microbianos.

First genotyping of Blastocystis sp. in dairy, meat, and cashmere goats in northwestern China.

Blastocystis is one of the most common parasites inhabiting in small intestines of human and animals. Although its pathogenicity has been remaining controversial, the possibility of zoonotic transmission between human and animals was recognized. The goat was one of the most important economic animals supplying people with cashmere, meat, and dairy products. However, few studies were to investigate Blastocystis infection in goats. A total of 789 faecal specimens of goats (including 362 of dairy, 193 of meat and 234 of cashmere goats) were collected from multiple regions of Shaanxi province in northwestern China to investigate the colonization frequency and subtypes of Blastocystis, and to assess the zoonotic potential of these goats. The respective colonization frequencies of Blastocystis in dairy, meat and cashmere goats were 54.1% (196/362), 40.4% (78/193) and 78.6% (184/234). The prevalence of Blastocystis in pre-weaned (0-2-month) goats was significantly lower than that in goats of other age groups, and the highest colonization was observed in goats of 7-11-month age group. Sequence analysis of Blastocystis positive samples indicated the presence of seven subtypes in these goats, including six known subtypes (STs1, 3, 4, 5, 10, 14) and one possible novel subtype (isolate Sd26), with the subtype 10 as the predominant one. Additionally, zoonotic subtypes were found in dairy (ST1, ST3 and ST5) and cashmere (ST4 and ST5) goats, but not detected in meat goats. These results showed that Blastocystis is highly prevalent, widely distributed and genetically diverse in goats in Shaanxi province, northwestern China, and zoonotic potential of dairy and cashmere goats to transmit Blastocystis.

Effects of temperature and different food matrices on Cyclospora cayetanensis oocyst sporulation.

Effects of temperature on the sporulation of the parasite Cyclospora cayetanensis were studied in 2 food substrates, dairy and basil. Unsporulated Cyclospora oocysts were subjected to freezing and heating conditions for time periods ranging from 15 min to 1 wk. Oocysts were then removed from the food substrates and placed in 2.5% potassium dichromate for 2 wk to allow viable unsporulated oocysts to differentiate and fully sporulate, and to determine the percentage sporulation as an indicator of viability. Sporulation occurred when oocysts resuspended in dairy substrates were stored within 24 hr at -15 C. When oocysts were placed in water or basil, sporulation occurred after incubation for up to 2 days at -20 C, and up to 4 days at 37 C. Few oocysts sporulated when incubated for 1 hr at 50 C. Sporulation was not observed in basil leaves or water at -70 C, 70 C, and 100 C. Sporulation was not affected when incubated at 4 C and 23 C for up to 1 wk, which was the duration of the experiment in both of the tested substrates.

Cryptosporidium parvum studies with dairy products.

Cryptosporidium parvum is a protozoan parasite capable of causing massive waterborne outbreaks. This study was conducted to model the transfer of C. parvum oocysts from contaminated water via food contact surfaces into yogurt and ice-cream, as well as to examine oocyst survival. Propidium iodide staining, combined with a direct immunofluorescence assay, was used for oocyst viability determination. Oocysts were recovered from milk products by a sucrose flotation-based procedure, with average recoveries of 82.3, 60.7, and 62.5% from low (1%) fat milk, 9% fat ice-cream, and 98% fat-free yogurt, respectively. Oocysts were also recovered, by rinsing with tap water, from stainless steel surfaces inoculated with oocyst suspension, with average recoveries of 93.1% when the surface was still wet and 69.0% after the surface had air-dried at room temperature. Viability of oocysts on the surface was significantly affected by desiccation; 5% of the oocysts remained viable after 4 h of air-drying at room temperature, while the proportion of viable oocysts was 81, 69, and 45% after air-drying for 10 min, 1 h, and 2 h, respectively. In contrast, oocyst viability only dropped from 82 to 75% after 30 min contact at room temperature with 5% bleach solution (equivalent to 0.26% NaOCl). Transfer of oocysts from milk and stainless steel surfaces into yogurt, and oocyst survival during the process were analyzed. Yogurt was made from pasteurized low fat milk and live yogurt starter by incubating at 37 degrees C for 48 h and then stored at 4 degrees C. Oocyst viability decreased from 83% (80%) to approximately 60% after 48 h at 37 degrees C and to approximately 58% following 8 days of storage, similar to oocyst survival in the controls using pasteurized milk without the addition of live yogurt. Oocyst survival in ice-cream was investigated by inoculating oocysts into ice-cream mix, and mixing and freezing in an ice-cream freezer, and hardening at -20 degrees C. Although approximately 20% (25 and 18%) of oocysts were viable before hardening, none were viable after 24 h at -20 degrees C. Control samples of oocysts suspended in distilled water and stored at -20 degrees C were taken at the same time intervals and 8% of the oocysts were still viable after 24 h.

Risks and prevention of contamination of dairy products.

Consumers and regulatory officials are becoming increasingly aware of the human health risk of the presence of micro-organisms or chemicals in the agricultural environment. Providing 'on-farm food safety' programmes which address the daily management of the production unit with regard to animal health and well-being, public health and environmental health must be a top priority for agriculturalists and veterinarians. Developing critical control point management (CCPM) procedures for animal and human health concerns is a viable approach to aid in alleviating public concerns about dairy products and the food supply in general. Such CCPM programmes may be created for individual production units based upon risk analysis, total quality management and hazard analysis and critical control point principles. Implementation of these programmes will be essential both in addressing food safety concerns for the resident population of a nation and in developing or maintaining international markets for the export of animal products.

Avaliação do consumo de leite e produtos lácteos informais e do conhecimento da população sobre os seus agravos à saúde pública, em um município do Estado de São Paulo, Brasil / Evaluation of consumption of milk and its informal derivatives and the knowledge of the population about the public health problems in a municipal district in São Paulo, Brazil

O leite é um alimento de elevado valor nutricional e considerado um dos principais produtos de origem animal consumidos nos dias de hoje. O Brasil destaca-se como um dos principais produtores de leite do mundo e desde 2006 vem apresentando aumento crescente em sua produção. Por outro lado, também se observa desde o início da década de 1990, crescimento do chamado leite e produtos lácteos informais (alimentos comercializados sem qualquer tipo de inspeção), representando desafio a ser vencido com relação à segurança alimentar. Muitas são as enfermidades que podem ser transmitidas por esses alimentos, como por exemplo, a tuberculose e a brucelose e poucos são os consumidores que estão atentos a essas informações. O fato agrava-se ao pensar que o leite e os produtos lácteos compõem a dieta de muitas crianças, idosos e pessoas imunocomprometidas, o que pode tornar esse quadro mais grave. O presente trabalho teve como objetivo avaliar, por meio da aplicação de questionários em 23 bairros do município de São José do Rio Preto, o perfil de 805 entrevistados, que consomem ou não leite e produtos lácteos, o conhecimento que os mesmos apresentavam sobre as doenças transmitidas pelo leite e seus derivados e o significado dos selos dos Serviços de Inspeção. Como resultado, observou-se que 97,76% (787/805) dos entrevistados consomem leite ou seus derivados, e aproximadamente 30% são obtidos por meios informais de comércio. A forma de consumo desse produto é bastante variável, mas 3,93% (31/787) dos consumidores do município ainda ingerem leite cru sem a fervura ou pasteurização e 65,96% (531/805) dos consumidores desconhecem a possível transmissão de doenças através da ingestão do leite. Além disso, 80,24% (646/805) dos consumidores não procuram nas embalagens se o produto passou por algum tipo de fiscalização antes de chegar ao comércio - identificação através dos selos dos órgãos de inspeção sanitária. A obtenção desses dados visou...(AU)

Milk is a food of high nutritional value and is considered one of the main animal products consumed today. At the same time, Brazil stands out as one of the leading milk producers in the world and, since 2006 has been showing growing increase in its production. On the other hand, it is observed from the beginning of the 1990s, the growth of so-called informal milk and milk products (foods marketed without any kind of inspection), representing a challenge to be overcome related to food security. There are many diseases that can be transmitted by such foods, as tuberculosis and brucellosis, and there are few consumers who are aware of such information. The fact worsens the thought that milk and dairy products make up the diet of many children, elderly and weakened persons, which may make it more severe. Thus, this study aims to evaluate, through the use of questionnaires in 23 districts of São José do Rio Preto, the profile of 805 consumers or not, of milk and dairy products, the knowledge that they have about the diseases transmitted by milk and dairy products and the significance of the seals from Inspection Services. As a result, it was found that 97.76% (787/805) respondents consume milk or its derivatives, and about 30% are obtained by informal means of commerce. The form of consumption of this product is quite variable, but the work shows that 3.93% (31/787) of the consumers still ingest raw milk without boiling or pasteurization and 65.96% (531/805) of consumers are unaware of the possible transmission of disease by the ingestion of milk. Furthermore 80.24% (646/805) of consumers do not seek the packaging if the product has gone through some kind of supervision before reaching the trade - identification through stamps organs of sanitary inspection. Obtaining such data aims to collaborate in future for the development of prevent programs in the city, and the information...(AU)

Avaliação do consumo de leite e produtos lácteos informais e do conhecimento da população sobre os seus agravos à saúde pública, em um município do Estado de São Paulo, Brasil / Evaluation of consumption of milk and its informal derivatives and the knowledge of the population about the public health problems in a municipal district in São Paulo, Brazil

O leite é um alimento de elevado valor nutricional e considerado um dos principais produtos de origem animal consumidos nos dias de hoje. O Brasil destaca-se como um dos principais produtores de leite do mundo e desde 2006 vem apresentando aumento crescente em sua produção. Por outro lado, também se observa desde o início da década de 1990, crescimento do chamado leite e produtos lácteos informais (alimentos comercializados sem qualquer tipo de inspeção), representando desafio a ser vencido com relação à segurança alimentar. Muitas são as enfermidades que podem ser transmitidas por esses alimentos, como por exemplo, a tuberculose e a brucelose e poucos são os consumidores que estão atentos a essas informações. O fato agrava-se ao pensar que o leite e os produtos lácteos compõem a dieta de muitas crianças, idosos e pessoas imunocomprometidas, o que pode tornar esse quadro mais grave. O presente trabalho teve como objetivo avaliar, por meio da aplicação de questionários em 23 bairros do município de São José do Rio Preto, o perfil de 805 entrevistados, que consomem ou não leite e produtos lácteos, o conhecimento que os mesmos apresentavam sobre as doenças transmitidas pelo leite e seus derivados e o significado dos selos dos Serviços de Inspeção. Como resultado, observou-se que 97,76% (787/805) dos entrevistados consomem leite ou seus derivados, e aproximadamente 30% são obtidos por meios informais de comércio. A forma de consumo desse produto é bastante variável, mas 3,93% (31/787) dos consumidores do município ainda ingerem leite cru sem a fervura ou pasteurização e 65,96% (531/805) dos consumidores desconhecem a possível transmissão de doenças através da ingestão do leite. Além disso, 80,24% (646/805) dos consumidores não procuram nas embalagens se o produto passou por algum tipo de fiscalização antes de chegar ao comércio - identificação através dos selos dos órgãos de inspeção sanitária. A obtenção desses dados visou...

Milk is a food of high nutritional value and is considered one of the main animal products consumed today. At the same time, Brazil stands out as one of the leading milk producers in the world and, since 2006 has been showing growing increase in its production. On the other hand, it is observed from the beginning of the 1990s, the growth of so-called informal milk and milk products (foods marketed without any kind of inspection), representing a challenge to be overcome related to food security. There are many diseases that can be transmitted by such foods, as tuberculosis and brucellosis, and there are few consumers who are aware of such information. The fact worsens the thought that milk and dairy products make up the diet of many children, elderly and weakened persons, which may make it more severe. Thus, this study aims to evaluate, through the use of questionnaires in 23 districts of São José do Rio Preto, the profile of 805 consumers or not, of milk and dairy products, the knowledge that they have about the diseases transmitted by milk and dairy products and the significance of the seals from Inspection Services. As a result, it was found that 97.76% (787/805) respondents consume milk or its derivatives, and about 30% are obtained by informal means of commerce. The form of consumption of this product is quite variable, but the work shows that 3.93% (31/787) of the consumers still ingest raw milk without boiling or pasteurization and 65.96% (531/805) of consumers are unaware of the possible transmission of disease by the ingestion of milk. Furthermore 80.24% (646/805) of consumers do not seek the packaging if the product has gone through some kind of supervision before reaching the trade - identification through stamps organs of sanitary inspection. Obtaining such data aims to collaborate in future for the development of prevent programs in the city, and the information...

[Experimental Trypanosoma cruzi infection via contaminated water and food]. / Infección experimental con Trypanosoma cruzi a través de agua y alimentos contaminados.

In order to determine the efficiency of different foods and water to maintain the infectivity of T. cruzi, the percentage of animals that resulted infected when they were ingested was registered. The materials were contaminated with metacyclic trypomastigotes from triatomine bugs feces, the infection in the mice were registered by directed observation of the parasite in the blood and corroborate by xenodiagnosis. Pasteurized milk infected the highest number of mice and the infectivity lasted longer than any other item tested. The efficacy of infectivity of fresh cheese and rice lasted after three hours and the percentage of infected mice was lower than with milk. Cooked and raw beefmeal and water resulted in the lowest, although similar number of infected mice. The infective capacity lasted only for a short time. It appears that the main differences obtained in infectivity depended on the different contents of moisture and nutrients in the solution.

Rastreabilidade de micro-organismos patogênicos ao longo da produção de leite pasteurizado: ferramenta potencial para a segurança alimentar / Traceability of pathogenic microorganisms along the pasteurized milk production: a potential tool for food safety

O objetivo do presente estudo foi monitorar a incidência de Staphylococcus aureus, Listeria sp., Listeria monocytogenes, Escherichia coli, coliformes totais, bactérias aeróbias mesófilas e psicrotróficas ao longo da produção de leite pasteurizado, desde a ordenha até a obtenção do produto final para estabelecer etapas e locais críticos da produção, bem como avaliar se a presença de Listeria sp. constitui um bioindicador de L. monocytogenes, e E. coli um bioindicador de outros micro-organismos patogênicos. As coletas foram feitas em 5 laticínios (A, B, C, D e E) do Estado de São Paulo, em duplicata, com intervalo de coleta variando de 3 semanas a 7 meses, de acordo com disponibilidade dos laticínios. Coletou-se um total de 236 amostras foram coletadas, sendo 36 de leite (cru e pasteurizado), 162 eram provenientes de superfícies que não tinham contato com o leite e 38 superfícies que entravam em contato com leite. Das 36 amostras de leite analisadas, 13,9% estavam contaminadas com Listeria sp. e nenhuma com L. monocytogenes; 61,1% continham E. coli e 5,6% apresentavam S. aureus. Somente o leite do laticínio C apresentou em uma das coletas micro-organismo patogênico (E. coli) no leite pasteurizado, indicando falhas no processamento ou no manejo no momento da ordenha. Das 38 amostras de superfícies com contato com o leite (38), 2,6% foram positivas para Listeria sp., 50,0% para E. coli e 5,3% para S. aureus. Das amostras de superfícies sem contato com o leite (162), 13,3% estavam contaminas com Listeria sp., 6,2% com L. monocytogenes e 25,9% com E. coli. De acordo com o limite estabelecido de aeróbios mesófilos no leite cru pela IN 62, constatou-se que 50,0% do leite cru dos laticínios A, D e E, 100% do leite cru do laticínio B e 33,3% do leite cru do laticínio C estão fora dos padrões estabelecidos pela legislação. Foi comprovado que a Listeria sp. não pode ser considerada como bioindicador de L. monocytogenes pelo teste Qui-Quadrado (p<0,05). Ao comparar as médias das amostras positivas para os microorganismos E. coli, S. aureus, Listeria sp. e L. monocytogenes dos laticínios processadores de leite tipo A com os de leite pasteurizado, somente o S. aureus no leite apresentou diferença significativa pelo teste \"T\" (p<0,05). Além dos pontos críticos de controle (PCC) checados através da Árvore Decisória (pasteurização, superfícies internas de embalagens), outros pontos merecem destaque pela elevada quantidade de patógenos (tanques de armazenamento de leite cru e pisos e paredes de câmaras frias). Os resultados obtidos ressaltam a importância da adoção de ferramentas de gestão da qualidade, como Boas Práticas de Fabricação e APPCC, para que a segurança alimentar seja garantida ao longo da cadeia de produção do leite pasteurizado nos laticínios estudados. (AU)

The aim of this study was to monitor the incidence of Staphylococcus aureus, Listeria sp., Listeria monocytogenes, Escherichia coli, total coliforms, mesophilic aerobic and psychrotrophic bacteria along the pasteurized milk production, from milking to the final product, to establish steps and critical points of production, as well as to evaluate the presence of Listeria sp. as a bioindicator of L. monocytogenes and E. coli a bioindicator of other pathogenic microorganisms. Duplicate samples were collected in 5 dairy plants (A, B, C, D, E) from the state of São Paulo, within intervals ranging from 3 weeks to 7 months, according to the dairy plants availability. A total of 236 samples were collected, being 36 of milk (raw and pasteurized), 162 from surfaces with no contact with the milk, and 38 from surfaces with contact with milk. Out of 36 milk samples analyzed, 13.9% were contaminated with Listeria sp. and none had L. monocytogenes; 61.1% were contaminated with E. coli and 5.6% with S. aureus. Only dairy plant C showed pathogenic microorganism (E. coli) in the pasteurized milk in one of the collections, indicating failures in the pasteurization or excessive bacterial load in the raw milk. Out of the 38 samples of surfaces that had contact with milk, 2.6% were positive for Listeria sp., 50.0% for E. coli and 5.3% for S. aureus. As for the samples from surfaces with no contact with milk (162), 13.3% were contaminated with Listeria sp., 6.2% with L. monocytogenes and 25.9% with E. coli. According to the Brazilian regulations for aerobic mesophiles in raw milk by Normative Instruction 62, 50.0% of samples from dairy plants A, D and E, 100% of samples from dairy plant B and 33.3% of samples from dairy plant C were above the tolerance limit adopted. The analysis of Listeria sp. could not be considered as a bioindicator of L. monocytogenes by chi-square test (p<0.05). When comparing the mean frequencies of positive samples for E. coli, S. aureus, Listeria sp. and L. monocytogenes in the processing dairy plants of type A milk (plants A and B) and the pasteurized one (plants C, D and E), only S. aureus in milk showed significant difference by \"T\" test (p<0.05). In addition to the critical control points (CCP) checked by a decision tree (pasteurization, internal surfaces of packaging), other points should be highlighted by the high number of pathogens found (bulk raw milk tanks, floors and walls of cold storage rooms). Results of this trial indicate the importance of adoption of quality management tools such as Good Manufacture Practices and HACCP, to ensure food safety along the pasteurized milk production chain in the dairy plants evaluated. (AU)

Rastreabilidade de micro-organismos patogênicos ao longo da produção de leite pasteurizado: ferramenta potencial para a segurança alimentar / Traceability of pathogenic microorganisms along the pasteurized milk production: a potential tool for food safety

O objetivo do presente estudo foi monitorar a incidência de Staphylococcus aureus, Listeria sp., Listeria monocytogenes, Escherichia coli, coliformes totais, bactérias aeróbias mesófilas e psicrotróficas ao longo da produção de leite pasteurizado, desde a ordenha até a obtenção do produto final para estabelecer etapas e locais críticos da produção, bem como avaliar se a presença de Listeria sp. constitui um bioindicador de L. monocytogenes, e E. coli um bioindicador de outros micro-organismos patogênicos. As coletas foram feitas em 5 laticínios (A, B, C, D e E) do Estado de São Paulo, em duplicata, com intervalo de coleta variando de 3 semanas a 7 meses, de acordo com disponibilidade dos laticínios. Coletou-se um total de 236 amostras foram coletadas, sendo 36 de leite (cru e pasteurizado), 162 eram provenientes de superfícies que não tinham contato com o leite e 38 superfícies que entravam em contato com leite. Das 36 amostras de leite analisadas, 13,9% estavam contaminadas com Listeria sp. e nenhuma com L. monocytogenes; 61,1% continham E. coli e 5,6% apresentavam S. aureus. Somente o leite do laticínio C apresentou em uma das coletas micro-organismo patogênico (E. coli) no leite pasteurizado, indicando falhas no processamento ou no manejo no momento da ordenha. Das 38 amostras de superfícies com contato com o leite (38), 2,6% foram positivas para Listeria sp., 50,0% para E. coli e 5,3% para S. aureus. Das amostras de superfícies sem contato com o leite (162), 13,3% estavam contaminas com Listeria sp., 6,2% com L. monocytogenes e 25,9% com E. coli. De acordo com o limite estabelecido de aeróbios mesófilos no leite cru pela IN 62, constatou-se que 50,0% do leite cru dos laticínios A, D e E, 100% do leite cru do laticínio B e 33,3% do leite cru do laticínio C estão fora dos padrões estabelecidos pela legislação. Foi comprovado que a Listeria sp. não pode ser considerada como bioindicador de L. monocytogenes pelo teste Qui-Quadrado (p<0,05). Ao comparar as médias das amostras positivas para os microorganismos E. coli, S. aureus, Listeria sp. e L. monocytogenes dos laticínios processadores de leite tipo A com os de leite pasteurizado, somente o S. aureus no leite apresentou diferença significativa pelo teste /"T/" (p<0,05). Além dos pontos críticos de controle (PCC) checados através da Árvore Decisória (pasteurização, superfícies internas de embalagens), outros pontos merecem destaque pela elevada quantidade de patógenos (tanques de armazenamento de leite cru e pisos e paredes de câmaras frias). Os resultados obtidos ressaltam a importância da adoção de ferramentas de gestão da qualidade, como Boas Práticas de Fabricação e APPCC, para que a segurança alimentar seja garantida ao longo da cadeia de produção do leite pasteurizado nos laticínios estudados.

The aim of this study was to monitor the incidence of Staphylococcus aureus, Listeria sp., Listeria monocytogenes, Escherichia coli, total coliforms, mesophilic aerobic and psychrotrophic bacteria along the pasteurized milk production, from milking to the final product, to establish steps and critical points of production, as well as to evaluate the presence of Listeria sp. as a bioindicator of L. monocytogenes and E. coli a bioindicator of other pathogenic microorganisms. Duplicate samples were collected in 5 dairy plants (A, B, C, D, E) from the state of São Paulo, within intervals ranging from 3 weeks to 7 months, according to the dairy plants availability. A total of 236 samples were collected, being 36 of milk (raw and pasteurized), 162 from surfaces with no contact with the milk, and 38 from surfaces with contact with milk. Out of 36 milk samples analyzed, 13.9% were contaminated with Listeria sp. and none had L. monocytogenes; 61.1% were contaminated with E. coli and 5.6% with S. aureus. Only dairy plant C showed pathogenic microorganism (E. coli) in the pasteurized milk in one of the collections, indicating failures in the pasteurization or excessive bacterial load in the raw milk. Out of the 38 samples of surfaces that had contact with milk, 2.6% were positive for Listeria sp., 50.0% for E. coli and 5.3% for S. aureus. As for the samples from surfaces with no contact with milk (162), 13.3% were contaminated with Listeria sp., 6.2% with L. monocytogenes and 25.9% with E. coli. According to the Brazilian regulations for aerobic mesophiles in raw milk by Normative Instruction 62, 50.0% of samples from dairy plants A, D and E, 100% of samples from dairy plant B and 33.3% of samples from dairy plant C were above the tolerance limit adopted. The analysis of Listeria sp. could not be considered as a bioindicator of L. monocytogenes by chi-square test (p<0.05). When comparing the mean frequencies of positive samples for E. coli, S. aureus, Listeria sp. and L. monocytogenes in the processing dairy plants of type A milk (plants A and B) and the pasteurized one (plants C, D and E), only S. aureus in milk showed significant difference by /"T/" test (p<0.05). In addition to the critical control points (CCP) checked by a decision tree (pasteurization, internal surfaces of packaging), other points should be highlighted by the high number of pathogens found (bulk raw milk tanks, floors and walls of cold storage rooms). Results of this trial indicate the importance of adoption of quality management tools such as Good Manufacture Practices and HACCP, to ensure food safety along the pasteurized milk production chain in the dairy plants evaluated.

Identification of lactic acid bacterial and enterobacteria: a technique in microplates

En este trabajo se desarrolla una microtécnica para la identificación de bacterias lácticas y bacterias enteropatogénicas. Los resultados fueron comparados con los obtenidos por el método convencional. se logró una reducción del volumen final y del tiempo de incubación para el estudio de fermentación de azúcares y otras propiedades bioquímicas en comparación con el ensayo tradicional. La correlación obtenida entre el ensayo en microplaca y el método convencional fue superior al 90 por ciento. La preparación de las microplacas con los diferentes reactivos pueden ser conservadas bajo condiciones de refrigeración durante 30 días antes de su empleo. La microtécnica puede ser considerada como un método sencillo, rápido y económico

Frecuencia de Listeria monocytogenes en derivados lácteos analizados en el Laboratorio de Salud Pública de la Secretaría Distrital de Salud de Bogotá en 2001 y 2002 / Frequency of Listeria monocytogenes in dairy products analyzed at the Public Health Laboratory of the District Health Secretariat of Bogota in 2001 and 2002

Durante los años 2001 y 2002, se analizaron derivados lácteos en el Laboratorio de Salud Pública (LSP) de la Secretaría Distrital de Salud (SDS) de Bogotá, que dieron como resultado cultivo positivo para Listeria monocytogenes, lo cual constituye un problema de salud pública, debido a la población de riesgo que afecta a maternas, niños, ancianos e inmunosuprimidos. Para determinar la frecuencia de L. monocytogenes en los derivados lácteos se utilizaron los registros de la base de datos correspondiente al análisis de estos alimentos en el LSP de la SDS de Bogotá durante 2001 y 2002; posteriormente se cruzaron las variables clase de derivado lácteo, hospital, causa de no aceptabilidad, objeto de muestreo y fosfatasa alcalina. La frecuencia de L. monocytogenes en los derivados lácteos fue para el 2001 del 6% y para el 2002, del 3%. Los alimentos más involucrados en la contaminación por este microorganismo fueron las cremas de leche y los quesos. En el 2001, sólo el 29% de los derivados lácteos contaminados por L. monocytogenes correspondieron a fosfatasa alcalina positiva, y en el 2002 fue del 24%. No existe relación directa entre la positividad de la fosfatasa alcalina con la presencia de L. monocytogenes en los derivados lácteos, y posiblemente la contaminación por este microorganismo sucedió después de la elaboración del producto o porque las células de L. monocytogenes pueden sobrevivir al tratamiento de pasteurización cuando se encuentran incluidas en los glóbulos grasos de la leche. Los resultados obtenidos en este estudio sirven para orientar el muestreo con enfoque de riesgo por parte de los hospitales en los derivados lácteos.

During 2001 and 2002, dairy products were analyzed at the Public Health Laboratory (LSP) of the District Health Secretariat (SDS) of Bogota, which resulted in positive cultures for Listeria monocytogenes, which constitutes a public health problem, due to the population at risk that affects mothers, children, the elderly, and the immunosuppressed. To determine the frequency of L. monocytogenes in dairy products, the records of the database corresponding to the analysis of these foods in the LSP of the SDS of Bogotá during 2001 and 2002 were used; subsequently, the variables class of dairy product, hospital, cause of unacceptability, object of sampling and alkaline phosphatase were crossed. The frequency of L. monocytogenes in dairy products was 6% in 2001 and 3% in 2002. The foods most involved in contamination by this microorganism were milk creams and cheeses. In 2001, only 29% of the dairy products contaminated by L. monocytogenes had positive alkaline phosphatase, and in 2002 it was 24%. There is no direct relationship between alkaline phosphatase positivity and the presence of L. monocytogenes in dairy products, and possibly the contamination by this microorganism occurred after the processing of the product or because L. monocytogenes cells can survive pasteurization treatment when they are included in the fat globules of the milk. The results obtained in this study serve to guide risk-based sampling by hospitals in dairy products.