Métodos alternativos para contagem de micro-organismos em carcaças suínas Alternative methods for the enumeration of microorganisms in swine carcasses

Micro-organismos estão presentes em toda a cadeia de processamento da carne, desde a matéria-prima até o produto final e compete aos programas de qualidade industrial verificar se existe contaminação na matéria-prima e nos produtos finais para, dessa forma, garantir um produto seguro ao consumidor. Para tanto, faz-se necessário utilizar metodologias alternativas à convencional na rotina diagnóstica dos laboratórios para obtenção de resultados confiáveis e em menor tempo possível. Com objetivo de verificar e comparar a correlação e o tempo de processamento, da metodologia convencional com as metodologias alternativas do sistema PetrifilmTM (3M) e sistema TEMPO® (bioMeriéux), foi realizada contagem de micro-organismos mesófilos, de enterobactérias e de Escherichia coli. As amostras foram coletadas da superfície de carcaças suínas em um abatedouro com Inspeção Federal no Estado de Santa Catarina, Brasil. A contagem de micro-organismos mesófilos, de enterobactérias e Escherichia coli foi feita por meio de ensaios realizados com os métodos alternativos TEMPO®, Petrifilm™ e o método convencional de contagem de micro-organismos em placas. Após análise estatística, o coeficiente de correlação de Pearson (r) demonstrou fortes correlações, acima de 0.70 entre as metodologias utilizadas para a contagem de enterobactérias e micro-organismos mesófilos, porém demonstrou moderada correlação, entre 0.30 a 0.70, para o diagnóstico de Escherichia coli. O uso dos métodos alternativos testados em substituição à metodologia convencional pode ser utilizado para diagnóstico de Escherichia coli, enterobactérias e micro-organismos mesófilos, por haver concordância entre os resultados encontrados, acrescido da rapidez dessas metodologias com benefício direto para a indústria de carne suína.Micro-organisms are present throughout the meat processing chain, from raw materials until finished product. Industrial quality programs check for contamination in raw materials and final products to ensure the safety of consumer products; for this reason, the use of alternative methods instead of the conventional methods used in routine diagnostic laboratories is necessary to obtain reliable results in the shortest time possible. Samples of pig carcasses were collected in a slaughterhouse with Federal Inspection in the State of Santa Catarina, Brazil. Mesophilic micro-organisms, Enterobacteriaceae and Escherichia coli were evaluated and tests performed by alternative methods, TEMPO®, Petrifilm™, and the conventional method of counting micro-organisms in Petri dishes. After statistical analysis, the Pearson correlation coefficient (r) showed a strong correlation up to 0.70 between the methodologies used for the enumeration of Enterobacteriaceae and mesophilic micro-organisms, show a moderate correlation between 0.30 to 0.70, for the diagnosis of Escherichia coli. The use of alternative methods to replace the conventional method can be recommended for diagnosis of Escherichiacoli, Enterobacteriaceae and mesophilic micro-organisms, because there was consistency between the results and the speed was increased by the alternative methodologies benefiting the pork industry

Chemical composition and antimicrobial activity of essential oils from selected herbs cultivated in the South of Brazil against food spoilage and foodborne pathogens Composição química e atividade antimicrobiana de óleos essenciais de plantas selecionadas cultivadas no Sul do Brasil contra micro-organismos patogênicos e deteriorantes de alimentos

The chemical composition of 10 selected plant essential oils obtained by steam distillation was determined by GC and GC/MS. The antimicrobial activity of the essential oils was screened against 12 important food-related bacterial strains by agar disc-diffusion assay. MIC and MBC were determined for the essential oils that presented the highest activity in the agar disc-diffusion test. The most active essential oils against the tested bacteria were, in descending order, lemongrass (Cymbopogon flexuosus), basil (Ocimum basilicum), oregano (Origanum vulgare), cinnamon leaf (Cinnamomum zeylanicum), and laurel (Laurus nobilis). Except for S. Typhimurium, the tested bateria were inhibited at MIC values lower or equal to 0.62mg mL-1 by lemongrass (Cymbopogon flexuosus) essential oil. Yersinia enterocolitica presented the highest sensitivity to all essential oils tested (CMI&#8804;0.62mg mL-1). There was a significant correlation (PA composição química de 10 óleos essenciais obtidos por destilação a vapor foi determinada por CG/DIC e CG/EM. A atividade antimicrobiana dos óleos essenciais foi detectada através do método de difusão em ágar frente a 12 espécies de bactérias de importância em alimentos. As CMI e CMB foram determinadas para os óleos essenciais que na difusão em ágar evidenciaram maior atividade. Os óleos essenciais que apresentaram maior atividade contra as bactérias testadas foram, em ordem decrescente, os de capim-limão (Cymbopogon flexuosus), manjericão (Ocimum basilicum), orégano (Origanum vulgare), folha de canela (Cinnamomum zeylanicum) e louro (Laurus nobilis). Com exceção de S. Typhimurium, o óleo essencial de capim limão (Cymbopogon flexuosus) apresentou valores de CMI e CMB iguais ou inferiores a 0,62mg mL-1 contra os micro-organismos testados. Yersinia enterocolitica foi o patógeno mais sensível frente a todos os óleos essenciais avaliados (CMI&#8804;0,62mg mL-1). Foi detectada correlação significativa (P<0,05) entre os níveis de monoterpenos oxigenados dos óleos essenciais e os valores de CMI e CMB contra Escherichia coli. Os resultados demonstram que os óleos essenciais avaliados apresentam grande potencial como agentes antimicrobianos naturais para alimentos

Ocurrence of Vibrio spp., positive coagulase staphylococci and enteric bacteria in oysters (Crassostrea gigas) harvested in the south bay of Santa Catarina island, Brazil Ocorrência de Vibrio spp., estafilococos coagulase positivo e bactérias entéricas em ostras (Crassostrea gigas) cultivadas na baía sul da ilha de Santa Catarina, Brasil

The aim of this study was to assess the contamination of oysters (Crassostrea gigas), harvested in six different regions of the South Bay of Santa Catarina Island, with Coliforms at 45 ºC, Escherichia coli, Vibrio spp., positive coagulase staphylococci, and Salmonella sp. over a period of one year. One hundred eighty oyster samples were collected directly from their culture sites and analyzed. Each sample consisted of a pool of 12 oysters. All of the samples analyzed showed absence of Salmonella, 18 (10%) samples showed presence of Escherichia coli, 15 (8.3%) samples were positive for V. alginolyticus, and Vibriocholerae was detected in 4 samples (2.2%). The counts of positive-coagulase staphylococci varied from O objetivo deste estudo foi avaliar a contaminação de ostras (Crassostrea gigas) cultivadas em diferentes regiões da Baía Sul da Ilha de Santa Catarina, por coliformes a 45 ºC, Escherichia coli, Vibrio spp. Estafilococos coagulase positiva e Salmonella sp., durante o período de um ano. Foram analisadas 180 amostras, coletadas diretamente no local de cultivo. Todas as amostras analisadas apresentaram ausência de Salmonella, 18 (10%) amostras apresentaram presença de Escherichia coli, 15 (8,3%) amostras positivas para Vibrio alginolyticus e V. cholerae foi detectado em 4 amostras (2,2%). As contagens de Estafilococos coagulase positiva variaram de <10 a 1,9 x 102 UFC.g-1, enquanto que as contagens de coliformes a 45 ºC e E. coli variaram de <3 a 1,5 x 102 NMP.g-1 e <3 e 4,3 x 10 NMP.g-1, respectivamente. As contagens de V. parahaemolyticus e V. vulnificus variaram de <3 a 7 NMP.g-1, para ambos os microrganismos, sugerindo um monitoramento tanto destas espécies quanto da temperatura das águas marinhas nas regiões de cultivo. Com base nos resultados das análises microbiológicas, as amostras analisadas mostraram qualidade bacteriológica aceitável, ou seja, dentro dos parâmetros estabelecidos na legislação brasileira

Ocurrence of Vibrio spp., positive coagulase staphylococci and enteric bacteria in oysters (Crassostrea gigas) harvested in the south bay of Santa Catarina island, Brazil

The aim of this study was to assess the contamination of oysters (Crassostrea gigas), harvested in six different regions of the South Bay of Santa Catarina Island, with Coliforms at 45 ºC, Escherichia coli, Vibrio spp., positive coagulase staphylococci, and Salmonella sp. over a period of one year. One hundred eighty oyster samples were collected directly from their culture sites and analyzed. Each sample consisted of a pool of 12 oysters. All of the samples analyzed showed absence of Salmonella, 18 (10%) samples showed presence of Escherichia coli, 15 (8.3%) samples were positive for V. alginolyticus, and Vibriocholerae was detected in 4 samples (2.2%). The counts of positive-coagulase staphylococci varied from <10 to 1.9 x 102 CFU.g-1, whereas the counts of Coliforms at 45 ºC and E. coli ranged from <3 to 1.5 x 102 MPN.g-1 and <3 and 4.3 x 10 MPN.g-1, respectively. Counts of V. parahaemolyticus and V. vulnificus ranged between <3 and 7 MPN.g-1, for both microorganisms. This suggests the need for monitoring these Vibrios contamination in oysters. Based on the results of the microbiological assays, the samples analyzed showed acceptable bacteriological quality, i.e., they were within the parameters established by Brazilian Legislation

Evaluation of the PetrifilmTM and TEMPO® systems and the conventional method for counting microorganisms in pasteurized milk

New microbiological methods have been developed and commercialized, but their performance must be guaranteed. The aim of the present study was to evaluate the PetrifilmTM and TEMPO® systems compared to the conventional method for counting microorganisms in pasteurized milk. A total of 141 samples of pasteurized milk were analyzed by counting mesophilic aerobic, Coliforms at 35 ºC, Coliforms at 45 ºC, and Escherichia coli microorganisms. High correlation was found between the methods for counting Coliforms at 35 ºC, but low correlation was found for counting mesophilic aerobic, Coliforms at 45 ºC, and Escherichia coli. No significant statistical difference was found among the three methods for counting Coliforms at 35 ºC; however, the mean counts of mesophilic aerobic, Coliforms at 45 ºC, and Escherichia coli showed significant statistical difference. PetrifilmTM and TEMPO® systems had satisfactory results for Coliforms at 35 ºC in pasteurized milk but low performance for mesophilic aerobic, Coliforms at 45 ºC and Escherichia coli