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1.
Biomédica (Bogotá) ; 41(supl.2): 165-179, oct. 2021. tab, graf
Article in Spanish | LILACS | ID: biblio-1355768

ABSTRACT

Resumen | Introducción. Listeria monocytogenes es un patógeno transmitido por alimentos que causa infecciones en humanos, entre ellas, meningitis, meningoencefalitis y septicemias, así como abortos. Con la tipificación serológica se han identificado 13 serotipos, siendo el 4b el causante de la mayoría de los brotes en el mundo. Objetivo. Determinar la frecuencia y la distribución de los serotipos y subtipos moleculares de L. monocytogenes aislados de alimentos en Colombia entre el 2010 y el 2018. Materiales y métodos. Se hizo un estudio descriptivo y retrospectivo a partir del análisis de 2.420 aislamientos que fueron identificados como L. monocytogenes y otras especies, por medio de pruebas bioquímicas, serológicas y de subtipificación molecular mediante electroforesis en gel de campo pulsado (PFGE). Resultados. De los 2.420 aislamientos recibidos, 2.326 fueron confirmados como L. monocytogenes. Los serotipos encontrados fueron: 4b (52%), 4d-4e (14,5%), 1/2a (11%), 1/2c (9,4%), 1/2b (9 %), y 3a, 3b, 3c, 4c, 4d, 4e y 7 (menos de 2%). Procedían de Bogotá (43%), Antioquia (25%), Valle (10%), Nariño (9%) y otros departamentos (7%). La caracterización genotípica agrupó los aislamientos evaluados en 167 patrones de PFGE; los perfiles más frecuentes se presentaron en productos lácteos, cárnicos y alimentos preparados. Conclusión. El 96,1 % de los aislamientos correspondieron a L. monocytogenes, con una buena concordancia entre el aislamiento y la identificación; el serotipo 4b, extremadamente virulento, fue el más frecuente. El análisis molecular evidenció la posible diseminación y permanencia en el tiempo de varios serotipos, lo que resalta la importancia de incluir este patógeno en los programas de vigilancia epidemiológica en alimentos.


Abstract | Introduction: Listeria monocytogenes is a food-borne pathogen that may cause infections in humans such as meningitis, meningoencephalitis, and septicemia, as well as abortions. By serological typing 13 serotypes have been identified of which 4b is responsible for most of the outbreaks in the world. Objective: To determine the frequency and distribution of serotypes and molecular subtypes of L. monocytogenes isolated in Colombia from food from 2010 to 2018. Materials and methods: We conducted a retrospective and descriptive study based on the analysis of 2,420 isolates confirmed as L. monocytogenes and other species using biochemical and serological tests, and pulsed-field gel electrophoresis (PFGE) for molecular subtyping. Results: Of the 2,420 isolates received, 2,326 were confirmed as L. monocytogenes. The serotypes found were 4b (52%), 4d-4e (14.5%), 1/2a (11%), 1/2c (9.4%), 1/2b (9%), and 3a, 3b, 3c, 4c, 4d, 4e and 7 (less than 2%). The isolates came from Bogotá (43%), Antioquia (25%), Valle (10%), Nariño (9%), and other departments (7%). The genotypic characterization grouped the isolates in 167 PFGE patterns. The most frequent patterns were identified in various dairy and meat products, and in prepared foods. Conclusion: A 96.1% of the isolates corresponded to L. monocytogenes showing good agreement between isolates and identification. Serotype 4b, highly virulent, was the most frequent. The molecular analysis showed the possible dissemination and permanence over time of several serotypes, which highlights the importance of including this pathogen in epidemiological food surveillance programs.


Subject(s)
Foodborne Diseases , Listeria monocytogenes , Electrophoresis, Gel, Pulsed-Field
2.
Arq. bras. med. vet. zootec. (Online) ; 73(4): 781-790, Jul.-Aug. 2021. tab, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1285278

ABSTRACT

The objective of the present study was to Standardize a Polymerase Chain Reaction (PCR) protocol for the authentication of bovine and buffalo milk, and to detect the presence of Salmonella spp. and Listeria monocytogenes. For this, the target DNA was extracted, mixed, and subjected to a PCR assay. Milk samples were defrauded and experimentally contaminated with microorganisms to assess the detection of target DNA at different times of cultivation, bacterial titers, and concentration of genetic material. In addition, the protocol was tested with DNA extracted directly from food, without a pre-enrichment step. The proposed quadruplex PCR showed good accuracy in identifying target DNA sequences. It was possible to simultaneously identify all DNA sequences at the time of inoculation (0h), when the samples were contaminated with 2 CFU/250mL and with 6h of culture when the initial inoculum was 1 CFU/250mL. It was also possible to directly detect DNA sequences from the food when it was inoculated with 3 CFU/mL bacteria. Thus, the proposed methodology showed satisfactory performance, optimization of the analysis time, and a potential for the detection of microorganisms at low titers, which can be used for the detection of fraud and contamination.


O objetivo do presente estudo foi padronizar um protocolo de reação em cadeia da polimerase (PCR) para a autenticação de leite bovino e bubalino e a detecção da presença de Salmonella spp. e Listeria monocytogenes. Para isso, o DNA-alvo foi extraído, misturado e submetido ao ensaio de PCR. Amostras de leite foram fraudadas e contaminadas experimentalmente com os micro-organismos, para se avaliar a detecção do DNA-alvo em diferentes tempos de cultivo, os títulos bacterianos e a concentração de material genético. Além disso, o protocolo foi testado com DNA extraído diretamente do alimento, sem a etapa de pré-enriquecimento. A PCR quadriplex proposta mostrou boa precisão na identificação de sequências de DNA-alvo. Foi possível identificar simultaneamente todas as sequências de DNA no momento da inoculação (0h), quando as amostras estavam contaminadas com 2 UFC/250mL, e com seis horas de cultura, quando o inóculo inicial foi de 1 UFC/250mL. Também foi possível detectar diretamente as sequências de DNA do alimento quando este foi inoculado com 3 UFC/mL de bactérias. Dessa forma, a metodologia proposta apresentou desempenho satisfatório, otimização do tempo de análise e potencial para detecção de micro-organismos em baixos títulos, podendo ser utilizada para detecção de fraude e contaminação.


Subject(s)
Animals , Cattle , Salmonella/isolation & purification , Buffaloes , Milk/microbiology , Fraud/prevention & control , Listeria monocytogenes/isolation & purification , Food Safety/methods , Multiplex Polymerase Chain Reaction/veterinary
3.
Diagn. tratamento ; 26(1): 12-15, jan.-mar. 2021.
Article in Portuguese | LILACS | ID: biblio-1247974

ABSTRACT

Contexto: A Listeria monocytogenes é um bacilo gram-positivo de baixa patogenicidade na população geral, mas importante causa de mortalidade por sepse e meningite em pacientes imunocomprometidos. Receptores de órgãos sólidos e candidatos em tratamento de dessensibilização são suscetíveis à infecção pela Listeria monocytogenes, embora sua apresentação clínica seja pouco reconhecida. Descrição dos casos: Paciente do sexo masculino, 43 anos, internado devido a rejeição aguda de enxerto pós-transplante renal, apresenta pico febril matutino e cefaleia. Paciente do sexo feminino, 59 anos, com doença renal crônica e em terapia de dessensibilização devido reatividade a painel antígeno leucocitário humano, busca pronto-socorro com febre, cefaleia e diarreia. A infecção por Listeria monocytogenes foi confirmada por hemocultura em ambos os casos. Discussão: A ocorrência de listeriose é esporádica e associada ao consumo de alimentos altamente contaminados, como laticínios, produtos frescos e carnes processadas. A redução da imunocompetência é o principal fator de risco para o desenvolvimento da doença em não gestantes, bem como para o aumento da mortalidade. O diagnóstico é estabelecido majoritariamente por hemocultura e o exame do líquido cefalorraquidiano é imprescindível para acessar o acometimento do sistema nervoso central, uma vez que os sinais meníngeos podem estar ausentes. O tratamento é realizado com beta-lactâmicos ou aminoglicosídeos. A ampicilina foi utilizada nos casos relatados e promoveu boa resposta clínica. Conclusão: Os profissionais devem atentar para a gravidade da infecção por Listeria monocytogenes e considerar sua ocorrência em pacientes imunocomprometidos, fornecendo orientações profiláticas a todos os candidatos a transplante de órgãos sólidos e tratamento empírico nos casos suspeitos.


Subject(s)
Humans , Male , Adult , Organ Transplantation , Desensitization, Immunologic , Kidney Transplantation , Listeriosis , Listeria monocytogenes
4.
Braz. j. biol ; 81(1): 69-76, Feb. 2021. tab
Article in English | LILACS | ID: biblio-1153335

ABSTRACT

Abstract The essential oil (EO) composition of leaves of Campomanesia aurea was analyzed by GC-MS. The plant was collected in April (EOA) and October (EOO) in São Francisco de Assis/RS. The essential oils were obtained by hydrodistillation in a modified Clevenger apparatus. The yields were 4.44% in April, and 6.15%, in October. Thirty-one compounds were identified in EOA, accounting for 96.87% of the total, and twenty-eight compounds were identified in EOO, accounting for 99.46% of the total. For EOA, the major identified monoterpene was p-cymene (8.33%) and the major identified sesquiterpene was α-cadinol (10.72%), while regarding EOO the major identified monoterpene was repeatedly Terpinolene (3.43%), whereas the major identified sesquiterpene was α-cadinol (12.79%). The antibacterial activity of the essential oil was evaluated against the three Listeria monocytogenes from the American Type Culture Collection (strains ATCC 7644, 19114 and 13932). The essential oil showed a MIC of 10 mg/mL against the strains ATCC 7644 and 19114, with bacteriostatic effect of 20 mg/mL and a MIC of 20 mg/mL for ATCC 13932. Regarding the antibiofilm activity, o EOO showed the best results with an inhibition of 90% in the sessile growth with an applied concentration of 4.0 mg/mL.


Resumo O óleo essencial (EO) das folhas de Campomanesia aurea foi analisado por CG-EM. O A planta foi coletada em abril (OEA) e outubro (OEO) em São Francisco de Assis/RS. Os óleos essenciais foram obtidos por hidrodestilação em aparelho Clevenger modificado. Os rendimentos foram de 4,44% em abril e 6,15% em outubro. Trinta e um compostos foram identificados no EOA, representando 96,87% do total, e vinte e oito compostos foram identificados no EOO, representando 99,46% do total. Para EOA, o principal monoterpeno identificado foi o p-cimeno (8,33%) e o principal sesquiterpeno identificado foi o α-candinol (10,72%), enquanto o EOO o maior monoterpeno identificado foi repetidamente Terpinolene (3,43%), enquanto o sesquiterpeno principal identificado foi α-cadinol (12,79%). A atividade antibacteriana do óleo essencial foi avaliada contra as três cepas de Listeria monocytogenes obtidas a partir da American Type Culture Collection (isolados ATCC 7644, 19114 and 13932). O óleo essencial apresentou uma CIM de 10 mg/mL contra as cepas ATCC 7644. e 19114, com efeito bacteriostático de 20 mg/mL e MIC de 20 mg/mL para ATCC 13932. Quanto à atividade antibiofilme, o EOO apresentou os melhores resultados com uma inibição de 90% no crescimento séssil com uma concentração aplicada de 4,0 mg/mL.


Subject(s)
Oils, Volatile/pharmacology , Listeria monocytogenes , Anti-Infective Agents , Microbial Sensitivity Tests , Plant Leaves
5.
Chinese Journal of Biotechnology ; (12): 3151-3161, 2021.
Article in Chinese | WPRIM | ID: wpr-921413

ABSTRACT

Listeria monocytogenes is an important food-borne pathogen. The distribution and survival of L. monocytogenes are related to its ability to form biofilms. Biofilms are resistant to adverse environments, and bacteria separated from the biofilms may lead to persistent food contaminations. The formation, maturation and structure of biofilms depend on a variety of external and internal factors, among which a variety of regulatory mechanisms play important roles. This review summarizes the regulatory mechanisms (including intracellular, intercellular and interspecific interactions) involved in the biofilm formation of L. monocytogenes in order to control the biofilm formation in food processing environments, thus providing new intervention strategy for food safety.


Subject(s)
Biofilms , Food Contamination , Food Safety , Listeria monocytogenes
6.
Chinese Journal of Biotechnology ; (12): 2453-2462, 2021.
Article in Chinese | WPRIM | ID: wpr-887811

ABSTRACT

The ban on addition of antibiotics in animal feed in China has made the search for new antibiotics substitutes, e.g. bacteriocin, a hot topic in research. The present study successfully isolated an antibacterial substance producing strain of Bacillus sp. from alpaca feces by agar diffusion method, using Escherichia coli, Salmonella enterica, Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus luteus and Listeria monocytogenes as indicator bacteria. The isolated strain was named as B. licheniformis SXAU06 based on colony morphology, Gram staining and 16S rRNA gene sequence. The antibacterial substance was isolated and purified through a series of procedures including (NH4)2SO4 precipitation, chloroform extraction, molecular interception and SDS-PAGE analysis. Bioinformatics analysis of the LC-MS/MS data indicated that the antibacterial substance was a bacteriocin-like substance (BLIS) with an approximate molecular weight of 14 kDa, and it was designated as BLIS_SXAU06. BLIS_SXAU06 exhibited high resistance to treatment of proteinase K, high temperature, high acidity and alkalinity. BLIS_SXAU06 was heterologously expressed in E. coli and the recombinant BLIS_SXAU06 exhibited effective antibacterial activity against S. aureus, S. epidermidis, M. luteus, and L. monocytogenes, showing potential to be investigated further.


Subject(s)
Animals , Anti-Bacterial Agents/pharmacology , Bacillus licheniformis , Bacteriocins/pharmacology , China , Chromatography, Liquid , Escherichia coli/genetics , Listeria monocytogenes , RNA, Ribosomal, 16S , Staphylococcus aureus , Tandem Mass Spectrometry
7.
Article in English | WPRIM | ID: wpr-880653

ABSTRACT

OBJECTIVES@#To investigate the clinical characteristics of patients with listeriosis and to provide a basis for diagnosis, treatment, prevention and control of hospital infection.@*METHODS@#A total of 10 inpatients, who suffered from the listeriosis in Xiangya Hospital, Central South University from January 2013 to June 2019, were retrospectively collected for this study. The characteristics of the patients' age, gander, basic information, case type, clinical manifestations, first consultation department, days of diagnosis, infection indicator, specimen type, results of drug sensitivity, treatment plan, hospital infection or not, outcome, follow-up data were analyzed.@*RESULTS@#Two cases were pregnant women and other were non-pregnant adults among 10 patients with listeriosis. Among them, there were 3 cases with hospital acquired infection. The age of patient onset was 27-71 years old, and the time from onset to diagnosis was 5-36 days. Five cases had fever, and other 5 cases had not fever. There were headache, fatigue, local pain, and other specialized symptoms in the 10 patients.The white blood cell count,the neutrophil ratio, the inflammatory index C-reactive protein, the procalcitonin were all increased, and the erythrocyte sedimentation was accelerated in the 10 patients.All the patients were sensitive to ampicillin, penicillin G, meropenem, and compound sinomine.@*CONCLUSIONS@#Listeriosis often affects the patients with low immunity, which often leads to misdiagnosis or missed diagnosis in clinic.So early prevention, early diagnosis, and early treatment can reduce mortality; it is important for departments of nosocomial infection management to manage patients' diet for avoiding outbreaks of listeriosis in hospital.


Subject(s)
Adult , Aged , Female , Humans , Listeria monocytogenes , Listeriosis/epidemiology , Meropenem , Middle Aged , Pregnancy , Pregnancy Complications, Infectious , Retrospective Studies
8.
Pesqui. vet. bras ; 40(10): 781-790, Oct. 2020. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1143415

ABSTRACT

The intensification of pig production and advances in the sanitary control of herds profoundly changed the profile of risk attributed to pork consumption. In the actual scenario, most microorganisms related to macroscopic lesions observed in the post mortem inspection are not transmitted by food, while foodborne bacteria of importance to consumer health do not cause macroscopic lesions. In Brazil, the "Ministério da Agricultura, Pecuária e Abastecimento" requested a scientific opinion on the prioritizing of pathogens potentially transmitted by unprocessed pork. After conducting a qualitative risk assessment, only Salmonella enterica was classified as of high risk to consumers. The present study was part of the validation step of the risk assessment and aimed to investigate the frequency of S. enterica, Yersinia enterocolitica and Listeria monocytogenes and hygienic-sanitary indicators in pig carcasses of pigs rose under intensive production and slaughtered under the Federal Inspection System in three slaughterhouses located in Southern Brazil. Additionally, the antimicrobial resistance profile of the isolated pathogens was also investigated. A total of 378 carcasses were sampled by superficial sponges before the chilling step in three slaughterhouses. Samples were investigated for the presence of the three aforementioned pathogens and subjected to enumeration of Colony Formation Units (log CFU.cm-1) of total aerobic mesophiles (TAM) and Enterobacteriaceae. Salmonella strains were tested by disc diffusion test for resistance to eleven antimicrobials. There were significantly statistical differences (p<0.0001) on the median counts of both indicators between the slaughterhouses. The median of TAM was very close for Slaughterhouses A and B: 1.573 log CFU.cm-1 and 1.6014 log CFU.cm-1, respectively. While in Slaughterhouse C, a higher TAM median was detected (2.216 log CFU.cm-1). A similar profile was observed regarding to Enterobacteriaceae, and medians were calculated as follow: -0.426 log CFU.cm-1 in Slaughterhouse A; 0.2163 log CFU.cm-1 in B; and 0.633 log CFU.cm-1 in C. Regarding the pathogens investigated, L. monocytogenes was not detected and only one carcass from Slaughterhouse C was positive for Y. enterocolitica. Thus, the results suggest a very low prevalence of L. monocytogenes and Y. enterocolitica in the sampled population. A total of 65 (17.2%) carcasses were positive for S. enterica, with a difference in frequencies between slaughterhouses and slaughter days. The prevalence of Salmonella positive carcasses was higher in the Slaughterhouse C (25.4%; CI 95% 19-32%) in comparison with A (9.5%; CI 95% 9-14%) and B (18.3%; CI 95% 12-24%). There was no significantly statistical association between Enterobacteriaceae counts and Salmonella isolation on carcass surface (p=0.69). The slaughtering day, nested within the slaughterhouse, explains 31.3% of Salmonella prevalence variability. S. Typhimurium (38.1%) was the most prevalent, followed by S. Infantis (30.1%). Among the 61 Salmonella strains tested for resistance to antimicrobials, 18 (31.6%) were full-susceptible. No strain displayed resistance to azithromycin, ceftazidime, cefotaxime and meropenem. The highest resistance frequency was displayed to tetracycline (54.1%), followed by ampicillin (50.82%), nalidixic acid (42.62%) and chloramphenicol (42.62). Multi-resistance was detected in 52.54% of the, strains. In conclusion, S. enterica is more prevalent in pre-chill pig carcasses than Y. enterocolitica and L. monocytogenes and thus should be prioritized in monitoring and control programs at slaughter. Salmonella serovars varied among slaughterhouses and present significant differences in their resistance to antimicrobials. Slaughterhouses that present higher medians of TAM or Enterobacteriaceae in a monitoring period may have higher S. enterica prevalences as well. However, there is a high variation of S. enterica prevalence among slaughter days, which cannot be always related to the hygienic indicators counts observed on a given day.(AU)


A intensificação da produção de suínos e os avanços no controle sanitário dos rebanhos alterou de forma importante o perfil de risco do consumo de carne suína. No cenário atual, a maioria dos microrganismos causadores de lesões macroscópicas detectáveis na inspeção post mortem não são transmissíveis por alimentos, enquanto bactérias de importância como causadoras de doenças transmitidas por alimentos não causam lesões macroscópicas. No Brasil, o Ministério da Agricultura, Pecuária e Abastecimento solicitou uma opinião científica sobre a priorização de patógenos potencialmente transmitidos pela carne suína in natura. Após conduzir uma avaliação de risco qualitativa, apenas Salmonella enterica foi classificada como de alto risco para o consumidor. O presente estudo foi parte da etapa de validação da avaliação de risco e objetivou: investigar a frequência de S. enterica, Yersinia enterocolitica e Listeria. monocytogenes; e enumerar indicadores higiênico-sanitários em carcaças de suínos abatidos sob inspeção federal em frigoríficos dedicados ao abate de suínos sob sistema intensivo de criação no sul do Brasil. Além disso, o perfil de resistência a antimicrobianos dos patógenos isolados foi investigado. A superfície de um total de 378 carcaças foi amostrada por esponjas, na etapa de pré-resfriamento em três matadouros frigoríficos (A, B, C). As amostras foram investigadas quanto à presença dos três patógenos acima mencionados e quanto à enumeração de Unidades Formadoras de Colônia (log UFC.cm-1) de mesófilos aeróbios totais (MAT) e Enterobacteriaceae. As cepas isoladas de Salmonella foram testadas quanto à resistência a onze antimicrobianos pela técnica de disco difusão. As medianas de contagem de ambos os indicadores apresentaram diferença significativa (p<0,0001) entre matadouros-frigoríficos. A mediana de MAT foi bastante próxima para A e B (1,573 log UFC.cm-1 e 1,6014 log UFC.cm-1, respectivamente), enquanto em C uma mediana de MAT mais elevada foi determinada (2,216 log CFU.cm-1). Um perfil semelhante foi observado em relação a Enterobacteriaceae, sendo as medianas calculadas para A, B e C, respectivamente: -0,426 log CFU.cm-1; 0,2163 log UFC.cm-1; e 0,633 log UFC.cm-1. Em relação aos patógenos investigados, L. monocytogenes não foi detectada e apenas uma carcaça, do Matadouro C, foi positiva para Y. enterocolitica. Portanto, os resultados sugerem uma prevalência muito baixa desses patógenos na população amostrada. Em um total de 65 (17,2%) carcaças houve isolamento de S. enterica, com diferença nas frequências observadas entre matadouros e dias de abate. A prevalência de carcaças positivas para S. enterica foi maior no Matadouro C (25,4%; IC95% 19-32%) em comparação com A (9,5%; IC95% 9-14%) e B (18,3%; IC95% 12-24%). Não houve associação estatística entre o número de Enterobacteriaceae e o isolamento de S. enterica na superfície das carcaças (p=0,69). O dia de abate agrupado por frigorífico explica 31,3% da variação na prevalência de Salmonella. O sorovar mais frequente de S. enterica foi Typhimurium (38,1%) seguido de S. Infantis (30,1%). Entre as 61 cepas de S. enterica testadas quanto à resistência a antimicrobianos, 18 (31,6%) foram totalmente suscetíveis aos antimicrobianos testados. Nenhuma cepa apresentou resistência a azitromicina, ceftazidima, cefotaxima e meropenem. As maiores frequências de resistência foram demonstradas contra tetraciclina (54,1%), ampicilina (50,8%), ácido nalidíxico (42,62%) e cloranfenicol (42,62%). Em 52,54% das cepas foi detectada multi-resistência. Em conclusão, S. enterica é mais prevalente em carcaças suínas no pré-resfriamento do que Y. enterocolitica e L. monocytogenes. Portanto, S. enterica deve ser priorizada em programas de monitoramento e controle ao abate. Os sorovares de Salmonella variam entre matadouros e apresentam diferenças significativas na resistência a antimicrobianos. Matadouros de suínos que apresentam medianas de MAT e Enterobacteriaceae num período de monitoramento podem apresentar também prevalências mais de altas de presença de S. enterica. Entretanto, há uma alta variabilidade na frequência de S. enterica entre dias de abate, e nem sempre há relação entre essa frequência e a contagem de indicadores higiênico-sanitários determinados num determinado dia.(AU)


Subject(s)
Animals , Yersinia enterocolitica/isolation & purification , Salmonella enterica/isolation & purification , Drug Resistance, Bacterial , Pork Meat/microbiology , Listeria monocytogenes/isolation & purification , Abattoirs , Sus scrofa
9.
Rev. baiana saúde pública ; 44(2): 177-188, 20200813.
Article in Portuguese | LILACS | ID: biblio-1366120

ABSTRACT

Listeria monocytogenes é um patógeno de origem alimentar que frequentemente causa infecções, podendo até ser fatal. Trata-se de um microrganismo ubiquitário, transmitido ao ser humano principalmente por meio dos alimentos, como os produtos prontos para o consumo. O objetivo deste estudo foi verificar os índices de positividade para L. monocytogenes em queijos e produtos cárneos à base de frango, analisados em um laboratório de microbiologia de alimentos do Rio Grande do Sul. A triagem inicial das amostras seguiu o protocolo AOAC, método n° 2004.02, 2004. A confirmação dos resultados positivos foi realizada conforme Instrução Normativa nº 62/2003 (Mapa) e ISO 11290-1:1996, Amd.1:2004. Foram analisadas 666 amostras de queijos de baixa umidade, 3.897 de média umidade e 826 de alta umidade. Dos produtos à base de frango foram analisadas 547 amostras de salsicha, 172 de mortadela e 24 de linguiça. O estudo verificou que os queijos de baixa umidade estão significativamente associados ao resultado positivo (p=0,002) para L. monocytogenes e os queijos de alta umidade associaram-se ao resultado negativo (p=0,002). Com relação aos produtos à base de frango, a salsicha esteve significativamente associada ao resultado negativo para L. monocytogenes (p≤0,01), e a mortadela significativamente associada ao resultado positivo (p≤0,01). Visto que de modo geral esses produtos são consumidos diretamente, sem o emprego de calor, sugere-se reforçar tanto o controle sobre as boas práticas de fabricação quanto o monitoramento dos produtos.


Listeria monocytogenes is a foodborne pathogen that often causes infections and may even be fatal. It is an ubiquitous microorganism, transmitted to humans mainly through food such as ready-to-eat products. This study sought to verify the positivity indexes for L. monocytogenes in cheese and chicken meat products, analyzed in a food microbiology laboratory in Rio Grande do Sul, Brazil. The initial sample screening followed the AOAC protocol, Method No. 2004.02, 2004. Confirmation of positive results was performed according to Normative Instruction 62/2003 (MAPA) and ISO 11290-1: 1996, Amd.1: 2004. A total of 666 low moisture, 3897 medium moisture and 826 high moisture cheese samples were analyzed. Of the chicken meat products, 547 wiener, 172 mortadella and 24 sausage samples were analyzed. Results showed that low moisture cheeses were significantly associated with a positive result (p=0.002) for L. monocytogenes, while high moisture cheeses were associated with a negative result (p= 0.002). As for chicken meat products, the wiener was significantly associated with the negative result for L. monocytogenes (p≤0.01) and the mortadella significantly associated with the positive result (p≤0.01). Since most of these products are consumed directly, without the use of heat, it is suggested to reinforce both the control over Good Manufacturing Practices and the monitoring of the products.


Listeria monocytogenes es un patógeno de origen alimentario causante muchas veces de infecciones, incluso fatales. Es un microorganismo ubiquitario, que se transmite al hombre principalmente a través de los alimentos, generalmente por productos listos para el consumo. El objetivo de este estudio fue verificar los índices de positividad para L. monocytogenes en quesos y productos cárnicos a base de pollo, analizados en un laboratorio de microbiología de alimentos de Rio Grande do Sul (Brasil). El tamizaje inicial de las muestras siguió el protocolo AOAC, método 2004.02, 2004. La confirmación de los resultados positivos fue realizada conforme a la Instrucción Normativa 62/2003 (Mapa) e ISO 11290-1:1996, Amd.1:2004. Se analizaron 666 muestras de quesos de baja humedad, 3.897 de media humedad y 826 de alta humedad. De los productos a base de pollo se analizaron 547 muestras de salchichas, 172 de mortadela y 24 de chorizos. Este estudio verificó que los quesos de baja humedad fueron significativamente asociados al resultado positivo (p=0,002) para L. monocytogenes, y los quesos de alta humedad al resultado negativo (p=0,002). En cuanto a los productos a base de pollo, las salchichas estuvieron significativamente asociadas al resultado negativo para L. monocytogenes (p≤0,01), y la mortadela fue significativamente asociada al resultado positivo (p≤0,01). Dado que la mayoría de estos productos son consumidos directamente, sin cocción, se sugiere un mayor control de las buenas prácticas de fabricación y de monitoreo de los mismos.


Subject(s)
Chickens , Monitoring , Dairy Products , Good Manufacturing Practices , Food Microbiology , Listeria monocytogenes
10.
Rev. chil. nutr ; 47(2): 281-285, abr. 2020. tab
Article in English | LILACS | ID: biblio-1115499

ABSTRACT

Synthetic preservatives are widely present in processed foods, but most of them have carcinogenic potential, requiring the development of new natural alternatives such as fruit extracts, for microbial control. The objective of the study was to evaluate the chemical characterization, antioxidant, and antimicrobial activity of the sugar apple pulp (Annona squamosa L.). Physicochemical characteristics were evaluated, an extract was prepared, and its antioxidant activity by DPPH method and antimicrobial by disk diffusion. Minimal inhibitory concentration and minimum bactericidal concentration against strains of Salmonella typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus were evaluated. The physicochemical analysis revealed that sugar apple pulp had 75.0% moisture, 3.0% ash, 4.0% protein, 0.2% lipids, 3.3% fibers, and 14.5% carbohydrates. The antioxidant activity of the extract by the DPPH method was 20.6%. The pulp extract from the sugar apple had inhibition zone for Staphylococcus aureus, satisfactory inhibitory effect against Staphylococcus aureus, Escherichia coli, Listeria monocytogenes, and Salmonella Typhimurium, but did not present a bactericidal effect. Sugar apple pulp presents adequate levels of nutrients and potential for food application due to its microbiological activity and antioxidant properties.


Los conservantes sintéticos están ampliamente presentes en los alimentos procesados, pero la mayoría tienen potencial carcinogénico, lo que requiere el desarrollo de nuevas alternativas naturales para el control microbiano, como los extractos de frutas. El objetivo del estudio fue evaluar la caracterización química, la actividad antioxidante y antimicrobiana de la pulpa de manzana de azúcar (Annona squamosa L.). Se evaluaron las características fisicoquímicas, y se evaluó su actividad antioxidante mediante el método DPPH y antimicrobiano por difusión en disco, concentración inhibitoria mínima y concentración bactericida mínima contra cepas de Salmonella Typhimurium, Escherichia coli, Listeria monocytogenes y Staphylococcus aureus. El análisis fisicoquímico reveló que la pulpa de manzana de azúcar tiene 75.0% de humedad, 3.0% de cenizas, 4.0% de proteínas, 0.2% de lípidos, 3.3% de fibras y 14.5% de carbohidratos. La actividad antioxidante del extracto por el método DPPH fue del 20.6%. El extracto de pulpa de la manzana de azúcar tenía zona de inhibición para Staphylococcus aureus, efecto inhibidor satisfactorio contra Staphylococcus aureus, Escherichia coli, Listeria monocytogenes y Salmonella Typhimurium, pero no presenta efecto bactericida. La pulpa de manzana de azúcar presenta niveles adecuados de nutrientes y potencial para la aplicación de alimentos debido a su actividad microbiológica y propiedades antioxidantes.


Subject(s)
Plant Extracts/pharmacology , Annona/chemistry , Anti-Bacterial Agents/pharmacology , Antioxidants/pharmacology , Salmonella typhimurium/drug effects , Staphylococcus aureus/drug effects , Carbohydrates/analysis , Plant Extracts/chemistry , Proteins/analysis , Microbial Sensitivity Tests , Escherichia coli/drug effects , Lipids/analysis , Listeria monocytogenes/drug effects , Anti-Bacterial Agents/chemistry , Antioxidants/chemistry
11.
Chinese Journal of Biotechnology ; (12): 2334-2344, 2020.
Article in Chinese | WPRIM | ID: wpr-878490

ABSTRACT

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.


Subject(s)
Food Microbiology , Listeria monocytogenes/genetics , Risk Assessment , Salmonella/genetics
12.
Chinese Journal of Biotechnology ; (12): 1378-1385, 2020.
Article in Chinese | WPRIM | ID: wpr-826839

ABSTRACT

Listeria monocytogenes (Lm) is zoonotic pathogen that can cause listeriosis, and vaccine is one of the effective methods to prevent this pathogen infection. In this study, we developed a novel vaccine that is a mixture of inactivated bacteria and Montanide™ ISA 61 VG, a mineral oil adjuvant, and evaluated the safety and immune response characteristics of this vaccine. The mice immunized with the ISA 61 VG adjuvant had high safety, and it could induce significantly higher titer of anti-listeriolysin O (LLO) antibody and higher value of IgG2a/IgG1 ratio compared with the group without the adjuvant. In particular, it could provide 100% immune protection against lethal doses of Lm challenge in mice. In summary, ISA 61VG adjuvant significantly enhanced the ability of inactivated listeria vaccine to induce humoral and cellular immune responses, thereby enhanced the protective immune response in the host, and it is a potential vaccine candidate for the prevention of Lm infection in humans and animals.


Subject(s)
Adjuvants, Immunologic , Pharmacology , Animals , Hemolysin Proteins , Allergy and Immunology , Pharmacology , Immunity, Cellular , Listeria monocytogenes , Allergy and Immunology , Listeriosis , Mice , Mice, Inbred BALB C , Vaccines, Inactivated , Allergy and Immunology
13.
Rev. argent. microbiol ; 51(4): 359-362, dic. 2019. graf
Article in English | LILACS | ID: biblio-1057401

ABSTRACT

Abstract Listeria monocytogenes is a foodborne pathogen. The recent alert for L. monocytogenes in vegetables from Argentina warns about the importance of reinforcing its isolation, characterization and subtyping in food, clinical and environmental samples. The aim of the present study was to compare the discriminatory power of enterobacterial repetitive interpower; genic consensus polymerase chain reaction (ERIC-PCR), automated ribotyping and pulsed-field gel electrophoresis (PFGE) to subtype strains of L. monocytogenes isolated from Argentine meat and environmental samples. Simpson's Diversity Index (DI) was calculated on the basis of based on the dendrograms obtained in the by cluster analysis, showing the following discriminatory power: ApaI-PFGE (0.980), AscI-PFGE (0.966), ribotyping (0.912), ERIC-PCR (0.886). The ID values between ApaI- and AscI-PFGE and between ribotyping and ERIC-PCR were not significantly different. Of the three techniques evaluated, PFGE showed the highest discriminatory power. However, the subtyping techniques should be accompanied by effective food monitoring strategies and reliable clinical and epidemiological studies.


Resumen Listeria monocytogenes es un patógeno alimentario. La reciente alerta por la presencia de L. monocytogenes en vegetales en Argentina advierte sobre la importancia de reforzar el aislamiento, la caracterización y la subtipificación de esta bacteria en muestras clínicas de alimentos y ambientales. El objetivo del presente estudio fue comparar el poder discriminatorio de enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR), la ribotipificación automatizada y la pulsed-field gel electrophoresis (PFGE) para subtipificar cepas de L. monocytogenes aisladas de carne y de muestras ambientales en Argentina. El índice de diversidad (ID) de Simpson, calculado a partir de los dendrogramas obtenidos en el análisis de agrupamiento, mostró los siguientes resultados: Apal-PFGE (0,980), AscI-PFGE (0,966), riboti-pado (0,912), ERIC-PCR (0,886). Los valores obtenidos no fueron significativamente diferentes al comparar entre Apal- y AscI-PFGE, ni entre ribotipadoy ERIC-PCR. De las técnicas evaluadas, la PFGE presentó el mayor poder discriminatorio. Sin embargo, las técnicas de subtipificación deberían acompañarse de estrategias de control de los alimentos efectivas y de estudios clínicos y epidemiológicos confiables.


Subject(s)
Bacterial Typing Techniques/methods , Listeria monocytogenes/classification , Discriminant Analysis , Ribotyping/methods , Listeria monocytogenes/isolation & purification
14.
Rev. chil. infectol ; 36(5): 585-590, oct. 2019. graf
Article in Spanish | LILACS | ID: biblio-1058084

ABSTRACT

Resumen Introducción: Listeria monocytogenes es un patógeno transmitido por alimentos que causa listeriosis, una enfermedad que puede presentarse como gastroenteritis febril o en una forma invasora que tiene altas tasas de mortalidad. Hasta el momento, ha sido poco estudiada la diversidad genética de cepas de L. monocytogenes aisladas desde pacientes, alimentos y fuentes ambientales en Chile. Objetivo: Caracterizar genéticamente cepas de L. monocytogenes de estos tres orígenes recibidas por el Instituto de Salud Pública de Chile (ISP) entre los años 2007 y 2014. Material y Métodos: Se seleccionaron 94 cepas de L. monocytogenes correspondientes a 94 pulsotipos diferentes identificados por electroforesis en gel de campo pulsado (PFGE), se extrajo ADN y se realizó serotipificación mediante reacción de polimerasa en cadena (RPC) y tipificación de secuencias multilocus (MLST). Resultados: El serotipo más común fue 4b (55,3%), seguido de 1/2a (25,5%), 1/2b (17%) y 1/2c (2,2%). Se identificaron 32 secuencias tipo (ST), de las cuales cuatro fueron nuevas, y las predominantes fueron ST1 (28,7%) y ST2 (13,8%). La totalidad de las cepas se agrupó en los Linajes I y II. Conclusiones: Se observó una gran variabilidad genética en las cepas de L. monocytogenes analizadas, siendo predominantes las secuencias tipo ST1 y ST2, ambas pertenecientes al Linaje I. Nuestros resultados contribuyen a conocer la estructura poblacional de este patógeno en Chile y su presencia en muestras clínicas, alimentos y el medio ambiente.


Background: Listeria monocytogenes is a foodborne pathogen that causes listeriosis, a disease that can present as febrile gastroenteritis or as an invasive form that has high mortality rates. So far, the genetic diversity of strains of L. monocytogenes isolated from patients, foods and environmental sources in Chile has been poorly studied. Aim: To characterize genetically L. monocytogenes strains received by the Institute of Public Health of Chile (ISP) between 2007 and 2014. Methods: We selected 94 strains of L. monocytogenes corresponding to 94 different pulsotypes identified by pulsed field gel electrophoresis (PFGE), DNA was extracted and serotyping was performed by polymerase chain reaction (PCR) and multilocus sequence typing (MLST). Results: The most common serotype was 4b (55.3%), followed by serotypes 1/2a (25.5%), 1/2b (17%) and 1/2c (2.2%). 32 sequence-type (ST) were identified, of which 4 were new, and the predominant ones were ST1 (28.7%) and ST2 (13.8%). All the strains of L. monocytogenes were grouped in Lineages I and II. Conclusions: A great genetic variability was observed in the strains of L. monocytogenes analyzed, being predominant the ST1 and ST2, both belonging to Lineage I. Our results contribute to know the population structure of this pathogen in Chile and its presence in clinical samples, food and the environment.


Subject(s)
Humans , Listeria monocytogenes/isolation & purification , Listeria monocytogenes/genetics , Time Factors , Genetic Variation , Serotyping , Chile , Polymerase Chain Reaction , Electrophoresis, Gel, Pulsed-Field , Environmental Microbiology , Multilocus Sequence Typing , Food Microbiology , Listeriosis/microbiology
15.
Bol. latinoam. Caribe plantas med. aromát ; 18(4): 411-424, jul. 2019. tab, ilus
Article in English | LILACS | ID: biblio-1008180

ABSTRACT

Thymol (2-isopropyl-5-methylphenol) is an aromatic monoterpene found in essential oils extracted from plants belonging to the Lamiaceae family, such as Thymus, Ocimum, Origanum, Satureja, Thymbra and Monarda genera. Growth and biofilm formation by Listeria monocytogenes CLIP 74902 were evaluate using three carbon sources in the presence of thymol. Specific growth rate (h-1) values at 37o with glucose, trehalose and cellobiose with the addition of thymol (µg/mL) 0 (control) and 750, were respectively: 0.22, 0.07; 0.14, 0.04; 0.11, 0.04. Lag periods obtained under the same conditions were (h): 8.19, 13.2; 22.5, 27.5; 23.1, 28.1. A marked antibiofilm activity was observed against the exposure with 750 µg/mL of thymol, showing a high percentage of inhibition: glucose (99 %), trehalose (97 %) and cellobiose (98%), compared to the control. The results suggest that thymol could be used to inhibit the growth and production of biofilms by L. monocytogenes in the food industry.


Timol (2-isopropil-5-metilfenol) es un monoterpeno aromático presente en los aceites esenciales extraídos de plantas pertenecientes a la familia Lamiaceae, como los géneros Thymus, Ocimum, Origanum, Satureja, Thymbra y Monarda. El crecimiento y formación de biopelícula por Listeria monocytogenes CLIP 74902 fueron evaluados utilizando tres fuentes de carbono en presencia de timol. La velocidad específica de crecimiento (h-1) a 37o con glucosa, trehalosa y celobiosa con la adición de timol (µg/mL) 0 (control) y 750, fueron respectivamente: 0.22, 0.07; 0.14, 0.04, 0.11, 0,04. Los períodos lag obtenidos en las mismas condiciones fueron (h): 8.19, 13.2; 22.5, 27.5; 23.1, 28.1. Una marcada actividad antibiofilm fue obtenida con 750 µg/mL de timol, mostrando un alto porcentaje de inhibición con glucosa (99%), trehalosa (97%) y celobiosa (98%), respecto al control. Los resultados sugieren que timol podría ser usado para inhibir el crecimiento y producción de biopelículas por L. monocytogenes en la industria alimentaria.


Subject(s)
Thymol/pharmacology , Biofilms/drug effects , Listeria monocytogenes/drug effects , Terpenes/pharmacology , Kinetics , Biofilms/growth & development , Environment , Fermentation , Food Microbiology , Listeria monocytogenes/growth & development
16.
Pesqui. vet. bras ; 39(5): 299-303, May 2019. graf
Article in English | LILACS, VETINDEX | ID: biblio-1012749

ABSTRACT

ABSTRACT: Listeriosis is a disease that affects several animal species, including humans, and has three different forms of presentation: encephalic, reproductive, or septicemic. The nervous form is caused mainly by the bacterium Listeria monocytogenes. In Brazil, this disease has already been described in sheep, goats, and cattle. There are no reports of the disease in buffaloes in Brazil and worldwide. The objective of this study was to describe an outbreak of listeric meningoencephalitis in buffaloes in the state of Pará, Brazil. The outbreak occurred in a property located in the municipality of Bujaru, in the eastern Amazon, from May to July 2016. In a herd of 47 buffaloes, three animals (Cases 1, 2 and 3), aged <40 days, presented a neurological condition with locomotion difficulty characterized by paralysis of the four limbs, hypoesthesia, lateral recumbency, and death. Morbidity was 6.38% and lethality was 100%. At necropsy, no significant macroscopic lesions were found. Samples of the central nervous system were collected, fixed in 10% buffered formalin, and routinely processed for histopathological analysis. The main microscopic changes observed were unilateral microabscesses in the brainstem composed predominantly of mononuclear cells, with fewer polymorphonuclear cells, and perivascular cuffs composed mostly of mononuclear cells and few neutrophils. Samples of Cases 1 and 2 revealed Gram-positive bacteria in the areas of necrosis by the Gram's stain technique. Samples of Case 1 were positive in immunohistochemistry for L. monocytogenes. Diagnosis of the nervous form of listeriosis was based on epidemiological data, clinical profile, and immunostaining for Listeria monocytogenes. Results showed that listeriosis should be considered in the differential diagnosis in buffaloes with nervous signs.


RESUMO: A listeriose é uma doença que afeta várias espécies animais, incluindo o homem, e possui três formas diferentes de apresentação: nervosa, abortiva ou septicêmica. A forma nervosa é causada principalmente pela bactéria Listeria monocytogenes. No Brasil a doença já foi descrita em bovinos, ovinos e caprinos, mas não foram encontrados relatos desta doença em búfalos no Brasil e no mundo. O objetivo deste trabalho foi descrever um surto de listeriose nervosa em búfalos no estado do Pará, Brasil. O surto ocorreu de maio a julho de 2016, em uma propriedade localizada no município de Bujaru, na Amazônia Oriental. Três bubalinos de um total de 47 animais (Casos 1, 2 e 3), menores de 40 dias, apresentaram um quadro clínico neurológico caracterizado por dificuldade de locomoção, paralisia dos quatro membros, diminuição da sensibilidade cutânea, decúbito lateral e morte. A morbidade foi de 6,38% e a letalidade de 100%. Na necropsia não foram encontradas lesões macroscópicas significativas. Amostras do sistema nervoso central foram coletadas e fixadas em formalina tamponada a 10% e processadas rotineiramente para análise histopatológica. As principais alterações microscópicas observadas foram microabscessos unilaterais no tronco encefálico, compostos predominantemente por células mononucleares, com menor número de polimorfonucleares, e manguitos perivasculares compostos predominantemente por células mononucleares e poucos neutrófilos. Amostras dos Casos 1 e 2 revelaram bactérias Gram positivas nas áreas de necrose na técnica de Gram. Amostras do Caso 1 resultaram positivas na imuno-histoquímica para L. monocytogenes. O diagnóstico da forma nervosa da listeriose foi baseado nos dados epidemiológicos, no quadro clínico patológico e na imunomarcação para Listeria monocytogenes. Os resultados demostram que a listeriose deve ser considerada no diagnóstico diferencial em bubalinos com sinais nervosos.


Subject(s)
Animals , Buffaloes/abnormalities , Listeriosis/epidemiology , Nervous System Diseases/veterinary , Listeria monocytogenes
17.
Article in Korean | WPRIM | ID: wpr-766829

ABSTRACT

PURPOSE: To report a case of anterior uveitis secondary to Listeria monocytogenes infection. CASE SUMMARY: A 57-year-old male presented to our clinic with ocular pain and decreased vision in the right eye for 2 days. The patient had a history of liver transplantation 2 years prior and used immunosuppressive agents. Listeria monocytogenes was identified in blood cultures 1 month before his visit. At presentation, best-corrected visual acuity (BCVA) of the right eye was counting fingers at 20 cm and the intraocular pressure (IOP) was 50 mmHg. Conjunctival hyperemia, corneal edema, keratic precipitates, and cells in the anterior chamber were observed in the right eye. The patient was diagnosed as anterior uveitis in the right eye. Conventional uveitis treatment was initiated but clinical features did not improve and black hypopyon appeared. The possibility of anterior uveitis caused by Listeria monocytogenes infection was considered. An anterior chamber tap and culture were conducted to identify pathogens. Anterior chamber antibiotic injections and systemic antibiotic injections were performed. One week after injection, the BCVA of the right eye improved to 0.4 and the IOP decreased to 14 mmHg. One month after injection, the BCVA of the right eye improved to 1.0 and the IOP decreased to 16 mmHg. No inflammation of the anterior chamber was observed. CONCLUSIONS: When nonspecific uveitis occurs in immunosuppressed patients, cultures and appropriate antibiotics should be considered because of the possibility of infection.


Subject(s)
Anterior Chamber , Anti-Bacterial Agents , Corneal Edema , Endophthalmitis , Fingers , Humans , Hyperemia , Immunosuppressive Agents , Inflammation , Intraocular Pressure , Listeria monocytogenes , Listeria , Liver Transplantation , Male , Middle Aged , Uveitis , Uveitis, Anterior , Visual Acuity
19.
São Paulo; s.n; s.n; 2019. 65 p. tab, graf.
Thesis in Portuguese | LILACS | ID: biblio-1007563

ABSTRACT

Bacteriocinas produzidas por bactérias láticas (BAL) apresentam um importante potencial de aplicação na bioconservação de alimentos, por sua ação antimicrobiana contra algumas espécies de microrganismos patogênicos de relevância, como Listeria monocytogenes. Este estudo analisou o efeito da interação entre cepas selecionadas de BAL produtoras de bacteriocinas com outras BAL viáveis ou não viáveis (bacteriocinogênicas ou não) na indução da produção de bacteriocinas. O efeito dos metabólitos produzidos por estas cepas na indução da bacteriocinogênese também foi avaliado. As cepas produtoras de bacteriocinas selecionadas para o estudo foram Lactobacillus sakei MBSa1, produtora de sakacina A e Pediococcus acidilactici ET34, produtora de pediocina, isoladas de salame e salmão defumado, respectivamente. A produção de pediocina por P. acidilactici ET34 foi avaliada também em leite em pó desnatado reconstituído, além de meio de cultura (caldo MRS). Os resultados indicaram que, quando em co-cultura com Enterococcus faecalis ATCC12755, Lactobacillus sakei ATCC15521 ou Listeria monocytogenes (cepas 104, 711 e 637), ou na presença do sobrenadante livre de células (SLC) dessas culturas, nenhuma das duas cepas testadas produziu maior quantidade de bacteriocina do que a produzida quando em monocultura ou na ausência do SLC. A bacteriocina produzida por P. acidilactici ET34 apresentou um efeito bacteriostático contra L. monocytogenes 104 no leite em pó desnatado reconstituído nas 12 h analisadas, com extensão da fase lag, de forma dose-dependente. Os resultados indicaram, também, que P. acidilactici ET34 não foi capaz de produzir pediocina no leite em pó desnatado reconstituído quando em monocultura ou em co-cultura, ao contrário do observado para o caldo MRS. Mais investigação é necessária para esclarecer os efeitos de possíveis interações entre as BAL presentes em um alimento, bem como o efeito dos componentes dos alimentos na produção das bacteriocinas pelas BAL bacteriocinogênicas


Bacteriocins produced by lactic acid bacteria (LAB) present an important application potential in food biopreservation, by their antimicrobial activity against some species of pathogenic microorganisms of relevance, such as Listeria monocytogenes. This study analyzed the effect of the interaction between selected strains of bacteriocin-producing LAB with other viable or non-viable LAB (bacteriocinogenic or not) in the induction of bacteriocin production. The effect of the metabolites produced by these strains on the induction of bacteriocinogenesis was also evaluated. The bacteriocin-producing strains selected for the study were Lactobacillus sakei MBSa1, producer of sakacin A and Pediococcus acidilactici ET34, producer of pediocin, isolated from salami and smoked salmon, respectively. The production of pediocin by P. acidilactici ET34 was also evaluated in reconstituted skimmed milk powder as well as culture medium (MRS broth). The results indicated that when co-cultivated with Enterococcus faecalis ATCC12755, Lactobacillus sakei ATCC15521 or Listeria monocytogenes (strains 104, 711 and 637), or in the presence of the cell free supernatant (SLC) of these cultures, neither of the two strains tested produced greater amount of bacteriocin than that produced in monoculture or in the absence of SLC. The bacteriocin produced by P. acidilactici ET34 presented a bacteriostatic effect against L. monocytogenes 104 in skimmed milk powder reconstituted in 12h, with extension of lag phase, in a dose-dependent manner. The results also indicated that P. acidilactici ET34 was not able to produce pediocin in the reconstituted skimmed milk powder when in monoculture or in co-culture, unlike that observed for the MRS broth. More research is needed to clarify the effects of possible interactions between BAL present in a food and the effect of food components on bacteriocin production by bacteriocinogenic BAL


Subject(s)
Bacteriocins/analysis , Lactic Acid , Food/toxicity , Pediocins/adverse effects , Listeria monocytogenes/isolation & purification
20.
Rev. salud bosque ; 9(1): 84-97, 2019. Tab, Ilus
Article in Spanish | LILACS, COLNAL | ID: biblio-1103094

ABSTRACT

La listeriosis es una enfermedad transmitida principalmente por alimentos contaminados con Listeria monocytogenes. Se presenta con mayor frecuencia en neonatos, mayores de 65 años, mujeres gestantes y pacientes inmunosuprimidos. La infección por L. monocytogenes durante la gestación se asocia a una importante morbimortalidad materno-fetal.Se reporta el caso de una mujer gestante de 29 años de edad con lupus eritematoso sistémico, a quien se le diagnosticó bacteriemia por L. monocytogenes. Durante la hospitalización, el cuadro clínico se complicó con hipertransaminasemia y, ante la presencia de trombocitopenia, se estableció el diagnóstico presuntivo de síndrome HELLP. El alto riesgo de morbimortalidad llevó a una finalización precoz de la gestación.La importancia de este trabajo clínico radica en presentar la dificultad en el diagnóstico y manejo en una paciente gestante de gran complejidad con una infección relativamente frecuente que puede pasar desapercibida.


Listeriosis is a disease mainly transmitted by food contaminated with bacteria called Listeria monocytogenes. It occurs more often in newborns, elder population, pregnant women and immunosuppressed patients. L. monocytogenes infection during pregnancy is associated to significant maternal mortality and morbidity. The case of a 29-year-old pregnant woman with history of Systemic Lupus Erythematosus is review. The said woman was diagnosed with bacteremia related to L. monocytogenes. During hospitalization, the patient experienced complications with hipertransaminasemia, which led to the presumptive diagnosis of HELLP in presence of thrombocytopenia. Given the high risk of mortality and morbidity, the pregnancy was terminated. The importance of the present clinical work lays in showing the difficulties embedded in diagnosing and handling a high-complexity pregnant patient presenting a frequent infection that would otherwise go undetected.


A listeriosis é uma doença transmitida principalmente por alimentos contaminados com Listeria monocytogenes. Apresentase com maior frequência em neonatos, maiores de 65 anos, mulheres gestantes e pacientes imunossuprimidos. Durante a gestação esta infeção associa-se a uma importante morbimortalidade materno-fetal. Foi reportado o caso de uma mulher gestante de 29 anos com antecedente de lúpus eritematoso sistémico, diagnosticada com bacteriemia por L. monocytogenes, na hospitalização teve complicações com hipertransaminasemia, foi estabelecido um diagnostico presuntivo de síndrome HELLP em presença de trombocitopenia. O alto risco de morbimortalidade levou a uma finalização precoce da gestação. A importância deste trabalho clínico radica em apresentar a dificuldade de diagnóstico e tratamento em pacientes gestantes de alta complexidade com infeção relativamente frequente, que pode passar desapercebida


Subject(s)
Humans , Female , Pregnancy , Pregnancy Complications, Infectious , HELLP Syndrome , Listeria monocytogenes , Lupus Erythematosus, Systemic
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