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1.
Braz. j. microbiol ; 49(3): 607-613, July-Sept. 2018. tab
Article in English | LILACS | ID: biblio-951802

ABSTRACT

Abstract The effect of different modified atmosphere packaging regimes on the behavior of Salmonella spp. on minced meat was studied. Minced meat was experimentally contaminated with a Salmonella spp. cocktail (S. Enteritidis, S. Typhimurium, S. Infantis and S. Arizonae), packaged under vacuum or modified atmosphere with initial headspaces containing 20%O2/50%CO2/30%N2 and 20%O2/30%CO2/50%N2) and stored at 3 ± 1 °C for 12 days. Samples were analyzed for Salmonella spp., viable and lactic acid bacteria count every third day. Salmonella spp. counts decreased during storage in all packaging types, with reductions of about 1.5 log CFU/g. A significant difference (p < 0.01) was noted between Salmonella spp. counts in meat packaged in vacuum and modified atmospheres, although there was no significant difference in Salmonella spp. count between meat packaged in 50%CO2, and meat packaged in 30%CO2. At the end of the study, there were significant differences (p < 0.01; p < 0.05) in total viable and lactic acid bacterial counts between meat packaged in vacuum and modified atmosphere, and the lowest counts were noted in meat packaged in modified atmosphere with 50%CO2.


Subject(s)
Animals , Cattle , Salmonella/growth & development , Food Packaging/methods , Microbial Viability , Meat/microbiology , Salmonella/isolation & purification , Salmonella/genetics , Swine , Vacuum , Colony Count, Microbial , Food Packaging/instrumentation , Meat/analysis
2.
Braz. j. microbiol ; 49(2): 310-319, Apr.-June 2018. tab, graf
Article in English | LILACS | ID: biblio-889225

ABSTRACT

Abstract The aim of this study was evaluated the biofilm formation by Staphylococcus aureus 4E and Salmonella spp. under mono and dual-species biofilms, onto stainless steel 316 (SS) and polypropylene B (PP), and their sensitivity to cetrimonium bromide, peracetic acid and sodium hypochlorite. The biofilms were developed by immersion of the surfaces in TSB by 10 d at 37 °C. The results showed that in monospecies biofilms the type of surface not affected the cellular density (p > 0.05). However, in dual-species biofilms on PP the adhesion of Salmonella spp. was favored, 7.61 ± 0.13 Log10 CFU/cm2, compared with monospecies biofilms onto the same surface, 5.91 ± 0.44 Log10 CFU/cm2 (p < 0.05). The mono and dual-species biofilms were subjected to disinfection treatments; and the most effective disinfectant was peracetic acid (3500 ppm), reducing by more than 5 Log10 CFU/cm2, while the least effective was cetrimonium bromide. In addition, S. aureus 4E and Salmonella spp. were more resistant to the disinfectants in mono than in dual-species biofilms (p < 0.05). Therefore, the interspecies interactions between S. aureus 4E and Salmonella spp. had a negative effect on the antimicrobial resistance of each microorganism, compared with the monospecies biofilms.


Subject(s)
Biofilms/drug effects , Cetrimonium Compounds/pharmacology , Disinfectants/pharmacology , Peracetic Acid/pharmacology , Salmonella/drug effects , Sodium Hypochlorite/pharmacology , Staphylococcus aureus/drug effects , Bacterial Adhesion/drug effects , Biofilms/growth & development , Colony Count, Microbial , Culture Media/chemistry , Environmental Microbiology , Microbial Interactions , Microbial Viability/drug effects , Polypropylenes , Salmonella/growth & development , Stainless Steel , Staphylococcus aureus/growth & development , Temperature , Time
3.
Braz. j. microbiol ; 44(3): 737-742, July-Sept. 2013. graf, tab
Article in English | LILACS | ID: lil-699806

ABSTRACT

Although many rapid and high throughput molecular methods have been developed in the recent years for the multiplex detection of foodborne pathogens, the simultaneous recovery and enrichment of sublethally injured cells is still a problem that needs to be considered. Combined with previous established multiplex real-time PCR assay, the capability of simultaneous recovery and enrichment of sublethally injured Salmonella, E. coli O157:H7 and L. monocytogenes cells was evaluated in a multiplex selective enrichment broth SEL. The injured cells were obtained by heat shock. After evaluation of different procedures, 1 h of recovery period prior to 20 h of enrichment was proved to be necessary for the detection of less than 10 CFU/5 mL broth of injured L. monocytogenes. When the detection method was applied to artificially contaminated ground beef, all the three injured pathogens could be simultaneously detected without discrimination by real-time PCR combined with SEL broth, the detection limit was < 5 CFU/10 g ground beef. Comparatively, when BPW was employed as the enrichment broth in the same detection procedure, injured L. monocytogenes could not be detected if the initially spiked level was below 10² CFU/10 g ground beef. Considering the capability of co-enrichment and high detection effectiveness, the real-time PCR assay combined with SEL broth herein appears to be a promising tool for high-throughput screening of a large number of processed food samples, which require either single or multiple pathogen detection. More important, the sublethally injured foodborne pathogen cells were also detectable.


Subject(s)
Humans , Bacteriological Techniques/methods , Culture Media/chemistry , /isolation & purification , Food Microbiology/methods , Listeria monocytogenes/isolation & purification , Salmonella/isolation & purification , /growth & development , High-Throughput Screening Assays/methods , Listeria monocytogenes/growth & development , Molecular Diagnostic Techniques/methods , Multiplex Polymerase Chain Reaction/methods , Salmonella/growth & development
4.
Arch. latinoam. nutr ; 62(4): 355-362, dic. 2012. ilus, tab
Article in Spanish | LILACS | ID: lil-714889

ABSTRACT

El Análisis de Peligros y Puntos de Control Crítico (HACCP) es una herramienta para la Gestión de Inocuidad de los alimentos que permite identificar los peligros físicos, químicos y biológicos asociados al proceso a través de toda la cadena productiva. Este trabajo tiene por finalidad diseñar el Programa de HACCP para el proceso de producción de cacao en polvo en una industria de alimentos venezolana. Previamente se evaluó el cumplimiento de las Buenas Prácticas de Manufactura (BPM) y los Procedimientos Operativos Estándar de Saneamiento (POES), elementos básicos para el establecimiento del HACCP. Se visitaron las instalaciones de varios proveedores a objeto de observar el cumplimiento de las Buenas Prácticas Agrícolas (BPA). Para el desarrollo del programa HACCP se aplicaron los siete principios básicos del mismo y las cinco tareas preliminares, conforme a la metodología descrita por el Codex Alimentarius.Conducido el análisis de peligros, se identificaron tres puntos de control críticos en la línea de proceso: descascarillado (control de ocratoxina A), fase de tostado (control de Salmonella) y detección de partículas metálicas. Se establecieron los Límites Críticos, los Procedimientos de Vigilancia, las Acciones Correctivas, los Procedimientos de Verificación y de Documentación, recomendándose implementar el Programa HACCP en la industria procesadora de cacao en polvo con la realización de los ajustes correspondientes en los casos donde sea necesario. Recientemente la ocratoxina A (OTA),ha sido relacionada con el cacao en grano. Aunque se ha señalado que el descascarillado es una medida de control efectiva para este peligro químico, se recomienda estudiar la prevalencia de OTA en el cacao producido en el país y validar la etapa del descascarillado como control de micotoxinas.


Design of an HACCP program for a cocoa processing facility. The HACCP plan is a food safety management tool used to control physical, chemical and biological hazards associated to food processing through all the processing chain. The aim of this work is to design a HACCP Plan for a Venezuelan cocoa processing facility.The production of safe food products requires that the HACCP system be built upon a solid foundation of prerequisite programs such as Good Manufacturing Practices (GMP) and Sanitation Standard Operating Procedures (SSOP). The existence and effectiveness of these prerequisite programs were previously assessed.Good Agriculture Practices (GAP) audit to cocoa nibs suppliers were performed. To develop the HACCP plan, the five preliminary tasks and the seven HACCP principles were accomplished according to Codex Alimentarius procedures. Three Critical Control Points (CCP) were identified using a decision tree: winnowing (control of ochratoxin A), roasting (Salmonella control) and metallic particles detection. For each CCP, Critical limits were established,the Monitoring procedures, Corrective actions, Procedures for Verification and Documentation concerning all procedures and records appropriate to these principles and their application was established. To implement and maintain a HACCP plan for this processing plant is suggested. Recently OchratoxinA (OTA) has been related to cocoa beans. Although the shell separation from the nib has been reported as an effective measure to control this chemical hazard, ochratoxin prevalence study in cocoa beans produced in the country is recommended, and validate the winnowing step as well.


Subject(s)
Cacao/standards , Food Inspection/methods , Hazard Analysis and Critical Control Points/methods , Ochratoxins/analysis , Decision Making, Organizational , Food Contamination/prevention & control , Food-Processing Industry/standards , Program Development , Quality Control , Safety Management , Salmonella/growth & development , Venezuela
5.
Rio de Janeiro; s.n; 2012. 130 f p.
Thesis in Portuguese | LILACS | ID: lil-756632

ABSTRACT

Enterobactérias produtoras de ESBLs são descritas tanto no ambiente hospitalar quanto na comunidade em todo o mundo. No Brasil, esses microrganismos também têm emergido como uma causa importante de infecções, sendo as enzimas CTX-M as prevalentes. O objetivo deste estudo foi analisar diferentes aspectos genotípicos relacionados à expressão da resistência aos antimicrobianos em cepas Escherichia coli e de Salmonella spp, tais como: a diversidade de ESBLs, os genes de resistência aos antimicrobianos e o conteúdo plasmidial. Os aspectos epidemiológicos das cepas produtoras de ESBLs também foram investigados. Foram estudadas 88 cepas de enterobactérias, sendo 43 E. coli e 45 cepas de Salmonella spp., de origem hospitalar e da comunidade (principalmente alimentos), isoladas na cidade do Rio de Janeiro. A expressão de ESBL foi observada em sete cepas de E. coli (7/43, 16,3%) e em uma cepa de Salmonella Typhimurium (1/45, 2,3%) e as enzimas foram identificadas como variantes de CTX-M e SHV-5, respectivamente. Entre as cepas de E. coli, a enzima CTX-M-2 foi a mais frequente (n = 4), sendo detectada em cepas isoladas de swab retal de pacientes hospitalizados, enquanto as enzimas CTX-M-59 (uma variante de CTX-M) (n = 1) e CTX-M-9 (n = 2) foram identificadas em cepas isoladas a partir de espécimes clínicos. Salmonella Typhimurium produtora de SHV-5 foi isolada do ambiente hospitalar (fórmula infantil). As cepas de E. coli produtoras das enzimas CTX-M pertenceram a grupos filogenéticos (A, B1, D) e STs (ST34, ST69, ST101) diferentes, sendo os genes blaCTX-M identificados em plasmídeos com tipo de replicon IncA/C de cerca de 150 kb (blaCTX-M-2, blaCTX-M-9, blaCTX-M-59) ou 80 kb (blaCTX-M-2)...


ESBL-producing Enterobacteriaceae have been described in hospitals and in the community worldwide. In Brazil, ESBL-producing Enterobacteriaceae have also emerged as an important cause of infections, being CTX-M enzymes the most prevalent ESBLs. The objective of this study was to analyze different genotypic aspects related to expression of antimicrobial resistance in isolates of Escherichia coli and Salmonella spp., such as: diversity of ESBLs, antibiotic resistance genes and plasmid content. Epidemiological features of ESBL-producing isolates were also investigated. We studied 88 isolates of enterobacteria, 43 E. coli and 45 Salmonella serotypes of hospital and community (mainly food) origin, isolated in the city of Rio de Janeiro. ESBL expression was observed in seven E. coli isolates (7/43; 16,3%) and in one Salmonella Typhimurium (1/45; 2,3%) and the enzymes identified as CTX-M variants and SHV-5, respectively. Among the E. coli isolates, CTX-M-2 was the most frequent (n=4), being detected in isolates recovered from rectal swabs of hospitalized patients, whereas CTX-M-59 (a CTX-M-2-variant) (n=1) and CTX-M-9 (n=2) were identified in E. coli isolated from clinical specimens. SHV-5-producing S. Typhimurium was isolated from the hospital environment (infant formula). CTX-M-producing E. coli belonged to different phylogenetic groups (A, B1, D) and STs (ST34, ST69, ST101), being blaCTX-M genes were identified in IncA/C plasmids of approximately 150 kb (blaCTX-M-2, blaCTX-M-9, blaCTX-M-59) or 80 kb (blaCTX-M-2)...


Subject(s)
Humans , beta-Lactamases , Drug Resistance, Microbial , Escherichia coli/growth & development , Salmonella/growth & development , Anti-Bacterial Agents , Drug Resistance, Bacterial , Escherichia coli/genetics , Escherichia coli/isolation & purification , Cross Infection/epidemiology , Polymerase Chain Reaction , Salmonella Infections , Salmonella/genetics , Salmonella/isolation & purification
6.
São Paulo; s.n; s.n; dez. 2011. 273 p. tab, graf, ilus.
Thesis in Portuguese | LILACS | ID: biblio-837171

ABSTRACT

A ocorrência de surtos de doencas associadas aos vegetais minimamente processados (VMP) tem chamado a atenção para a sua segurança microbiológica. A avaliação quantitativa de riscos permite que o impacto das materias-primas e processamento seja avaliado e os resultados obtidos sejam usados para gestão e comunicação do risco. Desta forma, o presente estudo objetivou quantificar o risco de infecções por Salmonella spp. e Listeria monocytogenes a partir do consumo de VMP no Brasil. Um total de quinhentas e doze amostras de VMP foram analisadas e foi possivel enumerar e detectar Salmonella em 0,4% e 0,4% das amostras, respectivamente. L. monocytogenes foi enumerada e detectada em 0,97% e 3,1% das amostras analisadas, respectivamente. Os isolados de Salmonella spp. (n=4) e L. monocytogenes (n=69) foram confirmados por PCR e caracterizados por sorotipagem tradicional. Os isolados de L. monocytogenes foram caracterizados quanto ao ribotipo, resistencia ao cloro, taxa de multiplicação (µ), capacidade de formação de biofilmes e presença de genes de virulência. O sorovar predominante entre Salmonella spp. foi S. Typhimurium. Em relação a L. monocytogenes, observou-se prevalência do sorotipo 4b e do ribogrupo DUP-1038 e presenca de genes de virulência em 100% (inlA) e 97% (inlC e inlJ) dos isolados. A maioria dos isolados de L. monocytogenes foi resistente a exposição a 125 ppm de cloro livre, e todos foram capazes de aderir ao aco inox, atingindo concentracoes acima de 4 log UFC/cm2. Testes-desafio foram conduzidos para determinar o potencial de multiplicação (δ) de cepas de Salmonella e L. monocytogenes em nove diferentes tipos of VMPs armazenados a 7°C e 15°C por 6 dias. O armazenamento a 15°C por 6 dias resultou nos maiores aumentos nas populações de L. monocytogenes em couve picada (δ= 3,34) e rúcula ((δ= 3,22), enquanto para Salmonella, as maiores populações foram observadas em rúcula (δ= 4,05) e escarola (δ= 2,80). Testes-desafios posteriores indicaram que a multiplicação dos dois patógenos em VMP foi mais pronunciada quando os mesmos foram embalados sob atmosfera modificada em comparação a embalagem em filmes perfurados. Modelos preditivos primários e secundários descrevendo a taxa de multiplicação e tempo de lag de Salmonella spp. e L. monocytogenes em VMP em função da temperatura de armazenamento (7, 10, 15, 20, 25 e 30°C) foram gerados. Verificou-se que os modelos gerados apresentaram a precisão necessária e foram adequados para modelagem da multiplicação dos dois patógenos em VMP. Os modelos de avaliação quantitativa de risco (AQR) foram construidos para determinar a probabilidade de infecção por Salmonella spp. e L. monocytogenes devido ao consumo de VMPs. Os modelos construidos com base nos dados levantados da literatura indicaram risco de infecção por Salmonella spp. e L. monocytogenes de 8.66 x 10-3 e 1.87 x 10-8, respectivamente, sendo necessário que medidas de mitigação do risco sejam adotadas


The occurrence of foodborne disease outbreaks linked to minimally processed vegetables (MPV) is concerning industries, consumers and governments worldwide. Quantitative risk assessments can estimate the impact of raw materials and processing practices and these estimates are used for risk management and risk communication. This study aimed at quantifying the risks of infection by Salmonella spp. and Listeria monocytogenes due to consumption of MPV in Brazil. A total of five hundred and twelve samples of MPV were analyzed and Salmonella was detected and enumerated in 0.4% and 0.4% of the samples, respectively. L. monocytogenes was enumerated and detected in 0.97% and 3.1% of the samples analyzed, respectively. Isolates of Salmonella spp. (n=4) and L. monocytogenes (n=69) were confirmed through PCR and characterized by traditional serotyping. The isolates of L. monocytogenes were characterized for their ribotype, resistance to chlorine, growth rate, (µ) and ability to form biofilms and presence of virulence factors. Among Salmonella spp., S. Thyphimurium was the most prevalent serovar. Among L. monocytogenes, prevalence of serotype 4b and ribotype DUP-1038 was observed. Virulence gene inlA was present in 100% of the isolates, and genes inlC and inlJ in 97%. The majority of L. monocytogenes isolates were resistant to up to 125 ppm of free chlorine and all isolates were able to attach to stainless steel coupons, reaching populations of up to 4 log10 CFU/cm2. Challenge tests were carried out to determine the growth potential (δ) of Salmonella and L. monocytogenes in nine types of MPV stored at 7°C and 15°C for 6 days. The storage of MPV at 15°C for 6 days resulted in the greatest increases in L. monocytogenes populations in shredded collard green (δ= 3.34) and arugula (δ= 3.22), whereas for Salmonella, the highest populations were found in arugula (δ= 4.05) and escarole (δ= 2.80). Further challenge tests indicated that multiplication of both pathogens in MPV was more pronounced when these products were packaged under modified atmosphere in comparison to packaging in perforated films. Primary and secondary predictive models describing the growth rate and lag time of Salmonella and L. monocytogenes in MPV as a function of storage temperature (7-30°C) were generated. The generated models were accurate and suitable for modeling the growth of pathogens in MPVs. Quantitative risk assessment (QRA) models were built to determine the probability of infection by Salmonella and L. monocytogenes due to consumption of MPVs. The models built using data available in the literature indicated that the risks of infection by these pathogens were 8.66 x 10-3 and 1.87 x 10-8, respectively, evidencing the need for adoption of risk mitigation measures


Subject(s)
Evaluation Studies as Topic/statistics & numerical data , Listeria monocytogenes/growth & development , Plants/classification , Risk Assessment/methods , Salmonella/growth & development , Listeria monocytogenes , Disaster Management
7.
Braz. j. microbiol ; 41(2): 497-500, Apr.-June 2010. ilus
Article in English | LILACS | ID: lil-545360

ABSTRACT

The antimicrobial susceptibility of 212 Salmonella strains isolated from patients and foods was evaluated and 45 percent were found to be resistant to nalidixic acid. Nalidixic acid resistant strains showed a higher minimal inhibitory concentration for ciprofloxacin than sensitive strains. During the study an increase of strains with reduced susceptibility to ciprofloxacin was also observed.


Subject(s)
Humans , Nalidixic Acid/analysis , Nalidixic Acid/isolation & purification , Ciprofloxacin/analysis , Disease Susceptibility , Drug Resistance, Microbial , Fluoroquinolones , Quinolones , Salmonella Infections , Salmonella/growth & development , Salmonella/isolation & purification , Food Samples , Microbial Sensitivity Tests , Patients , Methods
8.
Int. j. morphol ; 27(3): 705-713, sept. 2009. ilus
Article in English | LILACS | ID: lil-598926

ABSTRACT

The effect on Salmonella hadar growth was investigated using fresh sterile liquid medium (Pronadisa, Hispanlab) containing aqueous garlic extract (AGE) at different concentration (0, 11, 12, and 13 mg/ml). The garlic extract added at these final concentrations had a bacteriostatic effect on Salmonella hadar. The effect of these bacteriostatic concentration of AGE on the growth of the tested serovar, revealed a pattern of inhibition characterized by: (i) a transitory inhibition phase whose duration was proportional to AGE concentration (ii) a resumed growth phase which showed a lower rate of growth than in uninhibited controls, and (iii) an entry into stationary phase at a lower culture density. The minimal inhibitory concentration and minimum bactericidal concentrations were very close, garlic MIC was 12 mg/ml and the MBC was 14 mg/ml. Among enzymatic activities followed with the API-ZYM system, significant changes during the inhibition phase were detected. These biochemical changes represent an adaptative response towards the garlic stress. Some cellular enzymatic activities disappeared, whereas others were induced or maintained after AGE addition. TEM images of the samples treated with the bacteriostatic concentration of AGE (12 mg/ml) revealed the rupture of cell walls and nonhomogeneous disposition of cytoplasmic materials within treated bacteria.


El efecto sobre el crecimiento de Salmonella hadar fue investigado utilizando un medio líquido estéril fresco (Pronadisa, Hispanlab) conteniendo el extracto acuoso de ajo (EAA) en diferentes concentraciones (0, 11, 12 y 13 mg/ml). El extracto de ajo añadido con estas concentraciones tuvo un efecto bacteriostático sobre Salmonella hadar. La prueba serovar reveló un patrón de inhibición caracterizado por: (i) una fase de inhibición transitoria cuya duración fue proporcional a la concentración de EAA, (ii) una reanudación de la fase de crecimiento, la cual mostró una tasa más baja de crecimiento que controles sin inhibición, y (iii) una ingreso en fase estacionaria con una menor densidad de cultivo. La concentración mínima inhibitoria (CMI) y la concentración mínima bactericida (CMB) fueron muy cercanas, la CMI de ajo fue de 12 mg/ml y la CMB fue de 14 mg/ml. Las actividades enzimáticas seguidas con el sistema API-ZYM, mostraron cambios significativos durante la fase de inhibición. Estos cambios bioquímicos representan una respuesta adaptativa al estrés del ajo. Algunas actividades enzimáticas celulares desaparecieron, mientras que otras fueron inducidas o mantenidas después de la adición de EAA. Las imágenes de MET de las muestras tratadas con la concentración del bacteriostático EAA (12 mg/ml) revelaron la ruptura de las paredes celulares y la disposición no homogénea de materiales citoplasmáticos dentro de las bacterias tratadas.


Subject(s)
Garlic/chemistry , Plant Extracts/pharmacology , Salmonella/growth & development , Salmonella , Salmonella/ultrastructure , Anti-Bacterial Agents/pharmacology
10.
Säo Paulo; s.n; 1998. 94 p. ilus, tab, graf.
Thesis in Portuguese | LILACS | ID: lil-226184

ABSTRACT

Os métodos microbiológicos convencionais para pesquisa de Salmonella em alimentos säo lentos e trabalhosos, requerendo vários dias para sua execuçäo. Como resultado, tem-se observado um número cada vez maior de sistemas alternativos que se propöe a detectar o patógeno em um espaço de tempo. O presente trabalho teve como objetivo avaliar a eficiência de três desses novos sistemas, Oxoid Salmonella Rapid test (OSRTTM), Salmonella Screen Verify (SSV) e RevealTM, utilizando para tanto carcaças de frango, consideradas veículos importantes na transmissäo de Salmonella ao homem. Além disso, também procurou-se determinar através desses sistemas rápidos e da metodologia convencional de análise, a disseminaçäo de Salmonella durante as operaçöes ...


Subject(s)
Animals , Disease Transmission, Infectious , Food Microbiology , Salmonella/growth & development , Abattoirs , Culture Media , Food Contamination , Microbiological Techniques , Poultry Products , Salmonella Infections
11.
Rev. argent. microbiol ; 27(2): 57-69, abr.-jun. 1995. tab
Article in Spanish | LILACS | ID: lil-223464

ABSTRACT

Se evaluó el desempeño de los medios agar Rambach, agar xilosa-lisina-desoxicolato (XLD) con el agregado de diferentes concentraciones de tergitol tipo 4 o sulfato de sodio y de 7-etil-2-metil-4-undecanol (XLDT4), agar Salmonella-Shigella (SS) y agar sulfito de bismuto según Wilson-Blair (SB) utilizando serovariedades de Salmonella spp. y otras especies bacterianas de la flora intestinal de las aves. Los medios de cultivo selectivos fueron evaluados mediante recuento de bacterias viables, comparando estos resultados con los del agar base Columbia (ABC) adicionado con sangre bovina al 7 por ciento, para lo cual se emplearon las serovariedades de Salmonella spp. que con mayor frecuencia se aíslan en las aves de nuestro país. Además se analizaron muestras provenientes de pollos experimentalmente inoculados con distintas serovariedades de Salmonella. Los medios Rambach, SS y XLD o XLDT4 son adecuados para el aislamiento de salmonelas. En cambio el agar SB fue muy inhibidor para las salmonelas de interés veterinario. El agregado de novobiocina o tergitol al medio XLD no inhibio completamente a todas las cepas de Proteus. En el agar Rambach comercial no creció ninguna de las cepas de Proteus que habían desarrollado en los otros medios. Diversas bacterias contaminantes produjeron colonias similares a Salmonella en los agares Rambach, SS, XLD y XLDT4. Dado que las especies bacterianas contaminantes que desarrollan en los medios de cultivo son diferentes, es recomendable optimizar el diagnóstico sembrando las muestras en los agares SS, XLD o XLDT4 y simultáneamente también en agar Rambach


Subject(s)
Chickens/microbiology , Culture Media , Salmonella/classification , Salmonella/growth & development , Salmonella/isolation & purification , Zoonoses/microbiology , Argentina
12.
Rev. microbiol ; 26(1): 28-31, jan.-mar. 1995. tab
Article in Portuguese | LILACS | ID: lil-283824

ABSTRACT

Este estudo refere-se à avaliaçäo de métodos laboratoriais para o isolamento de salmonelas (10 elevado à terceira potência UFC/g) de amostras de maionese artificialmente contaminadas (pH entre 4.0 e 4.5), mantidas a 4ºC em temperatura ambiente. De cada amostra contaminada, alíquotas foram retiradas a cada 24h e submetidas aos seguintes procedimentos: plaqueamento direto em superfície em agar soja tríptica (TSA) seguido de período de reparo de 4h em temperatura ambiente e posterior adiçäo de agar SS e incubaçäo a 35ºC por 24h; plaqueamento direto em superfície em TSA seguido de período de reparo de 4h em temperatura ambiente e posterior adiçäo de agar Hektoen enteric e incubaçäo a 35ºC por 24h;pré-enriqueciemtno em água peptonada tamponada a 35ºC por 24h, enriqueciemtno seletivo em caldo tetrationato de Kauffmann, em caldo selenito-cistina e em caldo Rappaport-Vassiliadis, com incubaçäo a 35ºC por 24h, a 35ºC por 24h e a 43ºC por 24h, respectivamente, seguido de plaqueamento em agar SS e agar Hektoen enteric com incubaçäo a 35ºC por 24h. Näo foi notada nenhuma diferença significativa no comportamento dos três caldos de enriquecimento utilizados.


Subject(s)
Salmonella/growth & development , Salmonella/isolation & purification , Observer Variation
13.
Indian J Pathol Microbiol ; 1994 Oct; 37(4): 425-30
Article in English | IMSEAR | ID: sea-75553

ABSTRACT

Salmonella 3, 10: r organisms were examined ultrastructurally for their role in the initiation of infection in chicken ileum and studied 18 hr after, the organisms were seen located free as well as in contact with food particles. The surface features of the organisms revealed marked changes when they were located close to the ileal epithelial cell microvilli. The organisms were also seen having penetrated into intercellular spaces located in the interior of ileum. Many of them were seen phagocytosed by phagocytic cells.


Subject(s)
Animals , Chickens , Humans , Ileum/microbiology , Microscopy, Electron , Rabbits , Salmonella/growth & development , Salmonella Food Poisoning/microbiology
14.
Article in English | IMSEAR | ID: sea-111926

ABSTRACT

Interactions of Proteus morganii, Proteus mirabilis, Proteus sp. Klebsiella oxaenae and Serratia marcescens isolated from vegetable salads of mass feeding systems with Salmonella ferlac (a new subgenus VI of Salmonella) isolated from a hostel cook's hands and lizard droppings were recorded following in-vitro nephelometric analysis. Nephelometric analysis revealed inhibition of S. ferlac by all the tested isolates from fifth hour of mixed culture interaction. K. oxaenae was the strong inhibitor.


Subject(s)
Antibiosis , Enterobacteriaceae/physiology , Nephelometry and Turbidimetry , Salmonella/growth & development
15.
Rev. microbiol ; 21(3): 276-81, set. 1990. ilus, tab
Article in Portuguese | LILACS | ID: lil-280189

ABSTRACT

O estudo teve p0or objetivo o acompanhamento da sobrevivência de uma populaçäo mista de Salmonella tfyphi, S typhimurium e S. dublin em queijos Minas Padronizado durante a maturaçäo. A mistura de Salmonella spp foi inoculada ao leite cru previamente à elaboraçäpo dos queijos. Elaborou-se quatro tipos de queijos Minas Padronizado, os quais representaram os seguintes tratamentos: a) queijo de leite pasteurizado (controle); b) queijo de leite cru; c) queijo de leite cru tratado com 500 mg/l de H2O2. Os queijos elaborados foram jmaturados à temperatura ambiente (ñ25§C) por um período de 60 dias. Nesse período, a intervalos de 15 dias, os queijos foram avaliados quanto a presença ou ausência de Salmonella, contagem padräo em placas (UFC/g), coliformes totais (NMP/g) e pH. No primeiro dia de maturaçäo também foi avaliado os teores teores de gordura e umidade dos queijos. As salmonelas sobreviveram, nos queijos, por um período de 30-45 dias de maturaçäo, independente dos tratamentos com H2O2. Isso sugere que as transformaçöes bioquímicas qeu ocorreram durante a maturaçäo tornaram o queijo meio desfavorável à sobrevivência desse grupo de bactérias patogênicas. A contagem da populaçäo de bactérias mesófilas reduziu gradualmente, de 7,0x10 elevado a 7 a 4,4x10 elevado a 4 UFC/g, durante o período de maturaçäo dos queijos. Os tratamentos do leite cru com 200 e 500 mg/l de H2O2 foram eficazes na destruiçäo dos microorganismos produtores de gás do grupo coliforme, o que preveniu o estufamento precoce dos queijos durante a maturaçäo. O teor de gordura dos queijos näo foi afetado pelos tratamentos com H2O2. Por outro lado, esses tratamentos com H2O2, aumentaram significativamente o teor de umidade dos queijos. A cultura lática utilizada apresentou boa qualidade e conferiu alta acidez aos queijos. Nestes, no primeiro dia de maturaçäo, os valores de pH variaram entre 4,65 e 4,69. A partir daí, esses valores aumentaram gradualmente, chegando aos 60 dias de maturaçäo dos queijos, entre 5,52 e 5,60.


Subject(s)
Food Analysis/methods , Cheese/analysis , Cheese/microbiology , Food Contamination/analysis , Salmonella/growth & development
16.
Rev. farm. bioquim ; 10(1/2): 67-80, 1989.
Article in Portuguese | LILACS | ID: lil-108201

ABSTRACT

Apesar do efeito limitante do pH de sucos de frutas e outros substratos ácidos, constatou-se a presença de Salmonella e Escherichia coli nesse tipo de alimento, com envolvimento da primeira em surtos toxinfecciosos. Os microorganismos injuriados pelas condiçöes ácidas, ou por outras, de caráter adversas, apresentam lesöes a nível celular que os diferenciam das células normais. Nesta revisäo, o fenômeno da injúria será conceituado e caracterizado. Metodologias adequadas de reparo, evolvendo condiçöes especiais de cultivo e maiores requerimentos nutricionais seräo mostrados, evidenciando-se os reflexos práticos da injúria celular na microbiologia de alimentos e possível comprometimento da saúde pública.


Subject(s)
Beverages/analysis , Citrus/analysis , Food Contamination/analysis , Enterobacteriaceae/growth & development , Escherichia coli/growth & development , Food Microbiology , Salmonella/growth & development
17.
Lima; s.n; 1985. 66 p. tab, graf. (T-3225).
Monography in Spanish | LILACS | ID: lil-186930

ABSTRACT

Los caldos selectivos con cisteina HCL 0.05 por ciento, cubiertos con parafina resularon ser mas efectivas para la inhibición de pseudomonas aeroginosa que los caldos cisteinadas sin cubiertas de parafina. El caldo selenita fue más efectivo para dicha inhibición que el calcio tetrationate. El agar desoxicolato citrato (incubado aeróbica o anaeróbicamente) resultó el más efectivo para la inhibición, especialmente cuando se aisló a partir de caldos cisteinados parafinadas. El agar verde brillante rojo de fenal-lactosa incubada aeróricamente tambien resultó util para dicha inhibición, cuando se aisló a partir de caldo solenito cisteinado y parafinado. Siendo no recomendable la incubación anaeróbica debido a las variaciones de forma y color de las colonias. El agar bismuto sulfito es muy buen medio de cultivo respecto a la diferenciación de las colonias de ambos microorganismos, pero no se logró inhibir totalmente el crecimiento de pseudomonas, aunque hubo una notable disminución del crecimiento, cuando se incubó el agar bajo condiciones anaeróbicas.


Subject(s)
Pseudomonas aeruginosa/classification , Pseudomonas aeruginosa/growth & development , Pseudomonas aeruginosa/isolation & purification , Salmonella/classification , Salmonella/growth & development , Salmonella/isolation & purification , Agar/analysis , Agar/isolation & purification , Cysteine/administration & dosage , Cysteine/analysis
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