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Sample records for meningoencefalitis por listeria

  1. Manejo hospitalario de la meningoencefalitis bacteriana por S. Neumoniae

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    Roberto Álvarez Fumero

    2003-12-01

    Full Text Available La actitud terapéutica ante la meningitis bacteriana (MEB es uno de los retos más importantes a los que se enfrenta el pediatra, pues de su oportuno y adecuado manejo depende el pronóstico. Los cambios en la epidemiología de los síndromes neurológicos infecciosos bacterianos observados en Cuba a partir del año 2000, promovieron la implementación de modificaciones al régimen terapéutico antibiótico convencional. En este artículo, sin olvidar que el tratamiento ideal es el preventivo, se expone una revisión actualizada del manejo hospitalario de las MEB por S.pneumoniae, que incluye: adopción de medidas generales, instauración temprana de acciones dirigidas a atenuar los efectos perjudiciales de la respuesta inflamatoria sistémica, conducta específica contra el agente (antibioticoterapia y finalmente la identificación precoz e inicio de la rehabilitación de secuelas. Se hace énfasis en las modificaciones al esquema antibiótico adoptadas recientemente por la Comisión Nacional de SNI. Se exponen consideraciones sobre la introducción de la vancomicina en esquema antimicrobiano de las MEB por S.pneumoniae.The therapeutic attitude to face bacterial meningitis (BME is one of the most important challenges for pediatricians, since the prognosis depends on its timely and adequate management The changes in the epidemiology of the bacterial infectious neurological syndromes ocurred in Cuba from 2000 on, promoted the implementation of modifications in the conventional therapeutical antibiotic regimen. In this article, without forgetting that the ideal treatment is the preventive one, it is exposed an updated review of the hospital management of BME due to S.Pneumoniae that includes: adoption of general measures, early establishment of actions directed to alleviate the harmful effects of the systemic inflammatory reponse, specific conduct against the agent (antibiotic therapy and, finally, the identification and beginning of the

  2. Clinical behavior of Streptococcus pneumoniae meningoencephalitis Comportamiento clinico y terapéutico de la meningoencefalitis por Streptococcus pneumoniae

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    Raisa Bu-Coifiu Fanego

    2009-12-01

    Full Text Available OBJECTIVE: There was an increased number of cases of meningoencephalitis caused by Streptococcus pneumoniae, after the successful vaccination campaigns against Neisseria meningitidis and Haemophilus influenzae. This paper aims at describing the clinical characteristics, the laboratory findings, the complications, and the therapeutic management of these patients, who have been suffering from this disease since 1993 to 2006. METHOD: Twelve children with Streptococcus pneumoniae meningoencephalitis admitted to the pediatric hospital of San Miguel del Padron, City of Havana in this period were assessed. RESULTS: Children under one year are the most frequently affected. Septic shock and brain edema were the most severe complications. Three patients died, implying that this disease has a serious course. Early treatment of brain edema is very important to reduce mortality. The elective drugs for treatment of these cases of Streptococcus pneumoniae meningoencephalitis were vancomycin combined with cephalosporin, cefotaxime or ceftriaxone type. CONCLUSION: Patients with Streptococcus pneumoniae meningoencephalitis show clinical characteristics, complications, and sequels that are different to other bacterial meningoencephalitis, meaning that they could be helpful for physicians considering the differential diagnosis of meningoencephalitis.OBJETIVO: Existe un incremento de la meningoencefalitis producida por Streptococcus pneumoniae, después de las campañas exitosas de vacunación contra Neisseria meningitidis y Haemophilus influenzae. El objetivo de este trabajo es describir las caracteristicas clinicas, los hallazgos de laboratorio, las complicaciones y el manejo terapéutico de los pacientes que sufrieron esta enfermedad desde 1993 a 2006. MÉTODO: Se estudiaron doce niños con meningoencefalitis por Streptococcus pneumoniae ingresados en el Hospital Pediátrico de San Miguel del Padrón, Ciudad de La Habana en este periodo. RESULTADOS: Los ni

  3. Meningoencefalítis por Angiostrongylus cantonensís Informe de un caso atípico

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    Ernesto Arteaga

    1996-06-01

    Full Text Available La infección humana por Angiostrongylus cantonensis es conocida mundialmente como una de las principales causas de meningoencefalitis eosinofílica. Este informe corresponde al estudio clinico y anatomopatológico de un paciente fallecido en el Hospital General Calixto García de La Habana, con un cuadro de infección neurológica de evolución tórpida y en el que la autopsia demostró la presencia de este parásito en cerebro y pulmón. Los análisis de laboratorio clínico no revelaron aumento de los eosinófilos en la sangre ni en el líquido cefalorraquídeo. La escasa frecuencia, en nuestro medio, de este parasitismo en el hombre y, sobre todo, su presentación clínica atípica motivaron su información.

  4. Respuesta inmune intratecal y características clínicas de la meningoencefalitis por Neisseria meningitidis en pacientes inmunizados con la vacuna cubana VA-MENGOC-BC®

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    Elena Noris-García

    2008-08-01

    Full Text Available La morbimortalidad por la enfermedad meningocócica en Cuba disminuyó notablemente después de la introducción de la vacuna VA-MENGOC-BC®. Sin embargo, años después de ser vacunados se han reportado algunos niños que enfermaron. En este trabajo nos propusimos describir el comportamiento neuroinmunológico y clínico de esta enfermedad en 12 pacientes vacunados que fueron ingresados en el Hospital Pediátrico de San Miguel del Padrón con el diagnóstico de meningoencefalitis producida por Neisseria meningitidis. Se tomaron muestras de forma simultánea de sangre y líquido cefalorraquídeo para la cuantificación de albúmina e inmunoglobulinas mayores por inmunodifusión radial; para el análisis de los resultados se tomó como referencia el registro histórico de los resultados de ocho pacientes no inmunizados que enfermaron antes de incluir esta vacuna en el Esquema Nacional de Vacunación. La respuesta neuroinmunológica y las características clínicas de los pacientes vacunados resultaron diferentes a lo observado previamente en pacientes no vacunados. El grupo vacunado mostró un cuadro menos grave de la enfermedad. El patrón de síntesis intratecal de inmunoglobulinas fue diferente entre los dos grupos. La media de la síntesis intratecal de IgG, IgM e IgA fue significativamente superior en el grupo de los pacientes no vacunados. Este estudio nos permitió concluir que en la muestra estudiada la vacuna modificó la respuesta neuroinmunológica y el cuadro clínico de la enfermedad.

  5. Tratamiento antimicrobiano en la meningoencefalitis, Hospital Militar Central "Dr. Luis Díaz Soto", 2004-2011

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    María del Carmen Jiménez Martínez

    Full Text Available Introducción: las meningoencefalitis constituyen un grupo de gran importancia dentro de las enfermedades infecciosas, en las cuales la introducción de los antibióticos hizo posible que fuese curable, pero la morbilidad y la mortalidad de esta enfermedad continúan siendo inaceptablemente altas. Objetivo: identificar la terapia antimicrobiana usada en las meningoencefalitis. Métodos: estudio descriptivo, observacional y retrospectivo. Se estudiaron 150 pacientes con diagnóstico de meningoencefalitis viral o meningoencefalitis bacteriana confirmada por cuadro clínico, estudio citoquímico del líquido cefalorraquídeo o identificación del agente etiológico. Todos se atendieron en el período comprendido entre los años 2004 y primer semestre del 2011, en los servicios de Medicina y Pediatría del Hospital Militar Central "Dr. Luis Díaz Soto". Se empleó el diseño de un estudio de utilización de medicamentos que hace uso de la indicación-prescripción y el esquema terapéutico para este tipo de paciente. Resultados: se utilizó terapia antimicrobiana en el 18,67 % de pacientes con meningoencefalitis viral (23,93 % de 117 y el 22 % con bacteriana (100 % de 33 casos. Las antibioticoterapias más usadas fueron la ceftriaxona (como único antibiótico en la meningoencefalitis viral, y asociada (ceftriaxona más vancomicina en la meningoencefalitis bacteriana. El patógeno más aislado (Streptococcus pneumoniae fue tratado en la mayoría de los casos con ceftriaxona más vancomicina. La generalidad de los tratamientos para la meningoencefalitis bacteriana duró menos de 21 días. Conclusiones: se evidenció el uso de terapia antimicrobiana en pacientes con meningoencefalitis viral y la coincidencia entre la terapia empírica y la específica en la meningoencefalitis bacteriana.

  6. Meningoencefalite por Listeria monocytogenes em ovinos Meningoencephalitis in sheep caused by Listeria monocytogenes

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    Daniel R. Rissi

    2010-01-01

    Full Text Available São descritos sete casos de doença neurológica em ovinos por Listeria monocytogenes no Rio Grande do Sul e Paraná entre 2000 e 2007. Foram afetados ovinos com idades entre 12-24 meses. Os casos ocorreram no verão e início da primavera e os índices gerais de morbidade e letalidade foram de 3,15% e 100%, respectivamente. Quando essa informação estava disponível, nenhum dos ovinos afetados era alimentado com silagem. Em três propriedades havia contato próximo dos ovinos afetados com outras espécies. A evolução do quadro clínico foi de 12 horas a três dias e os sinais clínicos foram caracterizados por decúbito (7/7, desvio da cabeça (4/7, incoordenação (3/7, depressão (3/7, andar em círculos (2/7, cegueira unilateral, emagrecimento progressivo, febre, midríase, movimentos de pedalagem, nistagmo lateral, opistótono, paralisia flácida dos membros pélvicos ou dos quatro membros, salivação excessiva e tremores (1/7 cada. Histologicamente observou-se encefalite com microabscessos, predominantemente unilateral com variáveis graus de gliose e alterações degenerativas como esferóides axonais e infiltração de células Gitter. As lesões se estendiam desde a medula oblonga até o mesencéfalo. Antígenos de Listeria monocytogenes foram detectados por imuno-histoquímica em seções de tronco encefálico de todos os ovinos afetados. O diagnóstico foi realizado com base nos achados epidemiológicos e clinico-patológicos, e confirmado pela imuno-histoquímica (IHQ utilizando anticorpo policlonal anti-L. monocytogenes.Seven cases of neurological disease in sheep caused by Listeria monocytogenes in Rio Grande do Sul and Paraná state, southern Brazil are described. The cases occurred between 2000 and 2007 and 12-24-month-old sheep were affected. Overall morbidity and lethality rates were 3.15% and 100%, respectively. Cases occurred in the summer and early spring. When this information was available, affected sheep had not been

  7. Encefalitis del tallo cerebral y mielitis por Listeria monocytogenes

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    Aracelly Castro

    2013-09-01

    Full Text Available La romboencefalitis por Listeria monocytogenes es una presentación poco común de la listeriosis del sistema nervioso central; sin embargo, es la presentación más común en personas inmunocompetentes. Aun más rara es la combinación de romboencefalitis con mielitis causada por L. monocytogenes; no obstante, en este artículo se reporta un caso de encefalitis del tallo y mielitis grave en un paciente sin compromiso del sistema inmunitario. Se presenta un paciente de 21 años de edad, sin deficiencias del sistema inmunitario, que consumió productos lácteos no pasteurizados y, posteriormente, presentó un cuadro de cefalea, vómito, deterioro de su estado general y, finalmente, alteración del estado de conciencia y muerte. Consultó al Instituto Neurológico de Colombia y se hizo diagnóstico de encefalitis del tallo y mielitis por L. monocytogenes. Se discuten las diferencias entre el caso presentado y los reportados en la literatura científica. Ante un paciente con signos de compromiso del tallo cerebral, de posible origen infeccioso, es prudente iniciar tratamiento antibiótico para L. monocytogenes y, en caso de poca respuesta, escalar rápidamente en dicho tratamiento. También lo es extender el estudio radiológico hacia la columna vertebral, con el fin de descartar compromiso de la médula espinal.   doi: http://dx.doi.org/10.7705/biomedica.v33i3.1482

  8. Recuperación de listeria monocytogenes dañada subletalmente por efecto de la congelación

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    Blanco Gutiérrez, María del Mar

    1995-01-01

    Se han estudiado distintos aspectos relacionados con la influencia que ejerce la congelación sobre la viabilidad y el daño celular sobre las listerias en general y l. Monocytogenes, asi como distintas cuestiones con relación a la detección de listerias a partir de muestras que han sufrido un proceso de congelación. Respecto a la primera parte, hemos observado que la resistencia de l. Monocytogenes a los efectos letales y subletales de la congelación (-20 c) se ve influenciada por la concentra...

  9. Meningoencefalitis amebiana primaria: comunicacion de dos nuevos casos Venezolanos Primary amebic meningoencephalitis: two new cases report from Venezuela

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    Fátima Petit

    2006-12-01

    Full Text Available La meningoencefalitis amebiana primaria (MAP es infrecuente. Describimos dos nuevos casos de MAP en pacientes Venezolanos. Caso 1, Varón de 10 años, con fiebre, cefalea, vómitos y debilidad generalizada, y antecedente de inmersión en un estanque de agua días antes del inicio de sus síntomas, falleciendo 72 horas después del ingreso. Caso 2, Varón de 23 años con historia de cefalea, fiebre, vómitos, somnolencia y cambios de conducta. El paciente falleció 40 horas después. El estudio neuropatológico en ambos casos reveló MAP por Naegleria fowleri. La encefalitis por amebas anfizoicas debe sospecharse en casos de meningoencefalitis asépticas.Primary amebic menigoencephalitis (PAM is rare. Two cases of PAM in Venezuelan patients are described. Case 1, a 10 year-old male with headache, fever, vomiting. The patient swam in a water reservoir before the onset of his disease. He died during his third hospital day. Case 2, a 23 year-old male with a history of headache, fever, vomiting, drowsiness, and behavioral disturbances. The patient died on his second hospital day. The diagnosis in both cases was PAM due to Naegleria fowleri. Central nervous system infection by free-living amebas should be considered in meningoencephalitides with bacterial-free cerebro-spinal fluid.

  10. Las meningoencefalitis bacterianas en la población infantil cubana: 1998-2000

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    Félix Orlando Dickinson Meneses

    2002-06-01

    Full Text Available Se describen algunos aspectos epidemiológicos de las meningoencefalitis bacterianas (MEB en Cuba entre 1998 y el año 2000, según los datos de la Vigilancia Nacional de las MEB (VNMEB disponibles. Se reportaron un total de 530 casos en menores de 15 años en todo el país durante el período. El grupo de edad más afectado resultó el de menos de 5 años. Los agentes más frecuentemente identificados fueron Haemophilus influenzae tipo b (Hib, Streptococcus pneumoniae (Spn y Neisseria meningitidis (Nm. La incidencia de Hib disminuyó 4 veces por el efecto de la vacunación masiva, especialmente en los menores de 5 años, a partir del año 2000 Spn es el principal agente causante de MEB y el más letal en Cuba. La letalidad general se incrementó de 10,6 a 20,4 %, y fue el grupo de los de menos de 1 año uno de los más afectados. Futuros estudios permitirán profundizar en la epidemiología de estas infecciones y monitorear los cambios que ocurran como consecuencia de intervenciones.Somme epidemiological aspects of bacterial meningoencephalities that occurred in Cuba from 1998-2000 are described according to available data from the National Surveillance Service. A total of 530 cases involving children under 15 years old were reported throughout the country in this period of time. The most affected age group was under 5 years. The most frequent identified agents were Haemophilus influenzae type B(Hib, Streptococcus pneumoniae (Spn and Neisseria meningitidis (Nm. The incidence of Hib decreased by 4 times thanks to massive vaccination program, particularly in under 5 years-old children, from the year 2000 on. Spn is the main causative agent of bacterial meningoencephalities and the most lethal one in Cuba. General lethality rate increased from 10.6 to 20.4% and the under one-year old age group was the most affected. Further studies will allow deepening into the epidemiology of these infections and monitoring the changes that might occur as a

  11. Biocontrole de Listeria monocytogenes por Pediococcus acidilactici em couve minimamente processada Biocontrol of Listeria monocytogenes by Pediococcus acidilactici in fresh-cut kale

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    Wanessa Altimiras Costa

    2009-12-01

    Full Text Available Este estudo avaliou um sistema de biocontrole para inibição de Listeria monocytogenes em couve minimamente processada, objetivando sua segurança durante estocagem sob refrigeração e em condições de abuso de temperatura. O potencial inibitório de bactérias láticas tolerantes ao sal e psicrotróficas contaminantes naturais da couve e Lactobacillus plantarum, Lactobacillus delbrueckii ATCC 9649 e Lactobacillus casei CCT 1465 foram avaliadas contra L. monocytogenes. O isolado de couve identificado como P. acidilactici CCA3 inibiu L. monocytogenes a 10 e 15 °C em ágar MRS e foi selecionado como possível agente de biocontrole. O número de L. monocytogenes na couve minimamente processada aumentou 3,7 e 4,7 ciclos logarítmicos a 5 e 10 °C, respectivamente, após 20 dias de armazenamento e 4,6 ciclos logarítmicos após oito dias a 15 °C. Entretanto, quando 10(8 UFC.g-1 de P. acidilactici CCA3 foram inoculados no produto processado, o crescimento de L. monocytogenes reduziu 2,3 ciclos logarítmicos sob temperatura abusiva de 15 °C. A acidez titulável e as características sensoriais da couve não foram alteradas pela presença de CCA3 ao longo do período de vida útil. Estes resultados sugerem o potencial de aplicação dos bioconservantes na couve minimamente processada, que necessitam estar associados à refrigeração e sanitização para garantir segurança.This study evaluated a biological control system for the inhibition of Listeria monocytogenes in minimally processed kale focusing on its freshness under refrigeration and extreme temperatures. The inhibitory potential of salt and cold tolerant lactic bacteria from natural microflora of kale, Lactobacillus delbrueckii ATCC 9649, Lactobacillus plantarum, and Lactobacillus casei CCT 1465 strains were evaluated against L. monocytogenes. Pediococcus acidilactici CCA3 isolated from kale exhibited a large inhibition zone of L. monocytogenes at 10 and 15 °C in MRS agar and was

  12. DNA fingerprinting by ERIC-PCR for comparing Listeria spp. strains isolated from different sources in San Luis: Argentina Caracterización molecular por ERIC-PCR de cepas de Listeria spp. aisladas de diversos orígenes en San Luis: Argentina

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    A. Laciar

    2006-04-01

    Full Text Available In this study, a total of 24 Listeria spp. strains were analyzed. Twenty-two isolates were obtained in San Luis (Argentina from human, animal, and food samples. Two types of strains, Listeria monocytogenes CLIP 22762 and Listeria innocua CLIP 74915, were included as reference strains. All isolates were biochemically identified and characterized by serotyping, phage typing, and amplification of the flaA gene by polymerase chain reaction (PCR. Repetitive intergenic consensus (ERIC sequence-based PCR was used to generate DNA fingerprints. On the basis of ERIC-PCR fingerprints, Listeria spp. strains were divided into three major clusters matching origin of isolation. ERIC-PCR fingerprints of human and animal isolates were different from those of food isolates. In addition, groups I and II included ten L. monocytogenes strains, and only one Listeria seeligeri strain. Group III included nine L. innocua strains and four L. monocytogenes strains. Computer evaluation of ERIC-PCR fingerprints allowed discrimination between the tested serotypes 1/2b, 4b, 6a, and 6b within each major cluster. The index of discrimination calculated was 0.94. This study suggests that the ERIC-PCR technique provides an alternative method for the identification of Listeria species and the discrimination of strains within one species.En este estudio se analizaron 24 cepas de Listeria spp. De ellas, 22 fueron obtenidas en San Luis (Argentina, a partir de muestras humanas, de animales y alimentos. Se incluyeron 2 cepas de referencia Listeria monocytogenes CLIP 22762 y Listeria innocua CLIP 74915. Todos los aislamientos fueron identificados bioquímicamente y caracterizados por serotipificación, fagotipificación y detección del gen flaA por reacción en cadena de la polimerasa (PCR. Se generaron perfiles de bandas de ADN mediante la amplificación de secuencias repetitivas de consenso intergénico de enterobacterias (ERIC-PCR. De acuerdo a los resultados obtenidos por ERIC

  13. Listeria (Listeriosis)

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    ... The Listeria Initiative The Listeria Whole Genome Sequencing Project Publications Language: English (US) Español (Spanish) File Formats Help: How do I view different file formats (PDF, DOC, PPT, MPEG) on this site? Adobe PDF file Microsoft PowerPoint file Microsoft Word file Microsoft Excel file ...

  14. Variabilidad de las meningoencefalitis bacterianas en el Hospital Pediátrico "Pepe Portilla" Variability of the bacterial meningoencephalitis at "Pepe Portilla" Paediatric Hospital

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    Maydelin Fernández González

    2009-03-01

    Full Text Available Se realizó un estudio retrospectivo y prospectivo longitudinal de las Meningoencefalitis Bacterianas diagnosticadas en el Hospital Pediátrico "Pepe Portilla" en el año 2006 y 2007, con el objetivo de determinar los gérmenes que han aislado en dicha patología, comparándose con años anteriores desde 1992, analizando el impacto de la vacunación contra Neisseria meningitidis y Haemophilus influenzae. Los estudios de líquido cefalorraquídeo se realizaron como indican las normativas para estos casos. Se encontró que en el 2006 solo hubo un caso de meningitis a Neisseria meningitidis y en el 2007 dos casos de meningitis por Streptocuccus pneumoneae, y además que la incidencia de Neisseria meningitidis y Haemophilus influenzae disminuyó después de la aplicación de las vacunas VAMENGO BC y Hib de manera ostensible como lo hizo en el país en general, demostrándose la efectividad de dicha vacuna en nuestro medio.A retrospective-prospective and longitudinal study about Bacterial Meningoencephalitis diagnosed at "Pepe Portilla" Paediatric Hopital was carried out during 2006-2007 aimed at determining the isolated germs of this pathology comparing them with previous years (since 1992 and analyzing the impact of vaccination against Neisseria meningitidis y Haemophilus influenzae. The studies about cerebrospinal fluid were conducted as indicated by the rules towards these cases. Results showed that in 2006 only one case of meningitis a Neisseria meningitidis occurred and two cases of meningitis by Streptocuccus pneumoneae in 2007; besides the incidence of Neisseria meningitidis y Haemophilus influenza diminished after the vaccination with VAMENGON BC and Hib observed in all the country, showing the effectiveness of the vaccine in our environment.

  15. IgG2 immunodeficiency: association to pediatric patients with bacterial meningoencephalitis Inmunodeficiencia de IgG2: asociación en pacientes pediátricos con meningoencefalitis bacterianas

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    XIOMARA ESCOBAR-PÉREZ

    2000-03-01

    Full Text Available An IgG subclass deficiency is often associated with bacterial infections. We studied four pediatric patients suffering from meningoencephalitis, two of them due to Streptococcus pneumoniae and two due to Haemophilus influenzae type b. Simultaneous diagnostic serum and cerebrospinal fluid samples were taken during income. The four subclasses of IgG and albumin were quantified in both biologic fluids by radial immunodiffusion. Very low levels of seric IgG2 with non detectable cerebrospinal fluid IgG2 were found in the patients. No intrathecal IgG subclass synthesis was found in two patients. One patient with S. pneumoniae had IgG3 intrathecal synthesis. Intrathecal IgG1, IgG3 and IgG4 synthesis was found in one patient suffering from H. influenzae according with reibergrams. Substitutive therapy with intravenous gammaglobulin was given to the patients as part of the treatment.Las deficiencias por subclases de IgG se asocian frecuentemente con infecciones de origen bacteriano. Se estudian cuatro pacientes en edad pediátrica con meningoencefalitis, dos de ellos a Streptococcus pneumoniae y dos a Haemophilus influenzae tipo b. Se toman muestras simultáneas diagnósticas de suero y líquido cefalorraquídeo en el momento del ingreso. Se cuantificaron las cuatro sublclases de IgG y albúmina en ambos líquidos biológicos por inmunodifusión radial. Se encontró que los pacientes presentaban cifras muy disminuidas de IgG2 sérico y ningun exhibia IgG2 en el líquido cefalorraquídeo. Dos pacientes no sintetizaron ninguna subclase de IgG intratecalmente. Un paciente con S. pneumoniae sintetizó IgG3 intratecal. Uno de los pacientes con meningoencefalitis a H. influenzae sintetizó IgG1, IgG3 e IgG4 intratecalmente de acuerdo com el reibergrama. Estos pacientes recibieron terapia substitutiva com gammaglobulina intravenosa como parte de la medicación.

  16. Listeria and Pregnancy

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    ... Events Advocacy For Patients About ACOG Listeria and Pregnancy Home For Patients Search FAQs Listeria and Pregnancy ... Pregnancy PFS013, January 2017 PDF Format Listeria and Pregnancy Fact Sheets Food Poisoning in Pregnant Women The ...

  17. Characterization of Listeria monocytogenes isolates from cattle and ground beef by pulsed-field gel electrophoresis Caracterización de aislamientos de Listeria monocytogenes obtenidos de ganado y de carne molida de vacuno por electroforesis de campo pulsado

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    Claudia Foerster

    2012-09-01

    Full Text Available The aims of this study were to determine the occurrence of Listeria monocytogenes in cattle feces and ground beef, to characterize these strains by pulsed-field gel electrophoresis and to compare them to three listeria strains found in humans. Cattle from different origins (n = 250 and ground beef obtained from supermarkets (n = 40 were sampled. The results show low occurrence in cattle feces (0.4 % but a higher presence in ground beef (37 %. An important part of the ground beef strains (80 % had > 95 % similarity with a strain isolated from a human sporadic case and the ATCC 19115 used as control. The strain isolated from cattle feces had 93 % similarity to clone 009, previously associated with a listeriosis outbreak related to cheese. Cattle and ground beef can harbor virulent L. monocytogenes strains. Further studies in animals and animal products are needed to improve listeriosis control.Los objetivos de este estudio fueron determinar la presencia de Listeria monocytogenes en el ganado y en la carne molida de vacuno comercializada en Chile, caracterizar los aislados mediante electroforesis de campo pulsado y compararlos con los obtenidos en tres cepas que han producido listeriosis en humanos, en ese país. Se tomaron muestras de heces de bovinos (n = 250 y de carne molida obtenida en supermercados (n = 40. Se encontró una baja incidencia de este patógeno en las heces de bovinos (0,4 %; un solo animal, pero mayores porcentajes en la carne molida (37 %. Gran parte de las cepas encontradas en la carne molida (80 % mostraron una similitud mayor del 95 % con un caso esporádico de listeriosis y con la cepa de referencia ATCC 19115. La cepa aislada de bovino tuvo un 93 % de similitud con el clon 009, responsable de un brote asociado al consumo de queso, ocurrido en 2008. Se concluye que el ganado y la carne molida pueden albergar cepas virulentas de L. monocytogenes. Se necesita un mayor número de estudios en animales y en los productos que se

  18. Listeria monocytogenes: diagnostic problems

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    Beumer, R.R.; Hazeleger, W.C.

    2003-01-01

    The first isolation methods for the detection of Listeria spp. were generally based on the direct culture of samples on simple agar media, but isolation of the pathogenic Listeria monocytogenes was difficult. In time, new techniques were developed, based on a variety of selective and elective agents

  19. Rat hepatocyte invasion by Listeria monocytogenes and analysis of TNF-alpha role in apoptosis Invasão de hepatócitos de rato por Listeria monocytogenes e análise do papel do TNF-alfa na apoptose

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    Sânia Alves dos Santos

    2005-04-01

    Full Text Available Listeria monocytogenes, etiological agent of severe human foodborne infection, uses sophisticated mechanisms of entry into host cytoplasm and manipulation of the cellular cytoskeleton, resulting in cell death. The host cells and bacteria interaction may result in cytokine production as Tumor Necrosis Factor (TNF alpha. Hepatocytes have potential to produce pro-inflammatory cytokines as TNF-alpha when invaded by bacteria. In the present work we showed the behavior of hepatocytes invaded by L. monocytogenes by microscopic analysis, determination of TNF-alpha production by bioassay and analysis of the apoptosis through TUNEL technique. The presence of bacterium, in ratios that ranged from 5 to 50,000 bacteria per cell, induced the rupture of cellular monolayers. We observed the presence of internalized bacteria in the first hour of incubation by electronic microscopy. The levels of TNF-alpha increased from first hour of incubation to sixth hour, ranging from 0 to 3749 pg/mL. After seven and eight hours of incubation non-significant TNF-alpha levels decrease occurred, indicating possible saturation of cellular receptors. Thus, the quantity of TNF-alpha produced by hepatocytes was dependent of the incubation time, as well as of the proportion between bacteria and cells. The apoptosis rate increased in direct form with the incubation time (1 h to 8 + 24 h, ranging from 0 to 43%, as well as with the bacteria : cells ratio. These results show the ability of hepatocyte invasion by non-hemolytic L. monocytogenes, and the main consequences of this phenomenon were the release of TNF-alpha by hepatocytes and the induction of apoptosis. We speculate that hepatocytes use apoptosis induced by TNF-alpha for release bacteria to extracellular medium. This phenomenon may facilitate the bacteria destruction by the immune system.Listeria monocytogenes, agente etiológico de infecção grave de origem alimentar, utiliza mecanismos sofisticados de entrada no citoplasma

  20. Investigating Listeria Outbreaks

    Centers for Disease Control (CDC) Podcasts

    Dr. Emily Cartwright, Infectious Disease fellow at Emory University and former EIS Officer with CDC’s Division of Foodborne, Waterborne, and Environmental Diseases discusses foodborne Listeria outbreaks.

  1. Carrier status for Listeria monocytogenes and other Listeria species ...

    African Journals Online (AJOL)

    Background: Listeria organisms are documented to be zoonotic; one of the sources of infection is the domestic fowl where it could occur as in apparent infection. The carriage of Listeria monocytogenes and other Listeria in indigenous birds has not been documented in Kenya. Objective: To establish whether healthy looking ...

  2. Investigating Listeria Outbreaks

    Centers for Disease Control (CDC) Podcasts

    2013-01-04

    Dr. Emily Cartwright, Infectious Disease fellow at Emory University and former EIS Officer with CDC’s Division of Foodborne, Waterborne, and Environmental Diseases discusses foodborne Listeria outbreaks.  Created: 1/4/2013 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 1/8/2013.

  3. Two cases of listeria rhombencephalitis

    Directory of Open Access Journals (Sweden)

    Christopher Thomas Mansbridge

    2018-01-01

    Full Text Available Listeria rhombencephalitis (LRE is a rare encephalitis of the hindbrain that can present with a variety of neurological symptoms. It is a diagnostic challenge, but prompt antimicrobial therapy is important to prevent high rates of mortality and morbidity. We report two cases of LRE, with several contrasting clinical features and different disease courses. Despite being rare, it is important to consider listeria in patients with possible meningoencephalitis, even if cultures are negative. Empirical treatment of meningoencephalitis should provide coverage for listeria, especially if the patient is at risk of listeriosis or there is a potential history of listeria exposure.

  4. Cutaneous anthrax in Lima, Peru: retrospective analysis of 71 cases, including four with a meningoencephalic complication Ántrax cutáneo en Lima, Perú: análisis retrospectivo de 71 casos, incluyendo cuatro con complicación meningoencefálica

    Directory of Open Access Journals (Sweden)

    Ciro Maguiña

    2005-02-01

    Full Text Available Anthrax is a zoonosis produced by Bacillus anthracis, and as an human infection is endemic in several areas in the world, including Peru. More than 95% of the reported naturally acquired infections are cutaneous, and approximately 5% of them can progress to meningoencephalitis. In this study we review the clinical and epidemiological characteristics of the patients with diagnosis of cutaneous anthrax evaluated between 1969 and 2002 at the Hospital Nacional Cayetano Heredia (HNCH and the Instituto de Medicina Tropical Alexander von Humboldt in Lima, Peru. Seventy one patients were included [49/71 (69% of them men], with a mean age of 37 years. The diagnoses were classified as definitive (44% or probable (56%. The most common occupation of the patients was agriculture (39%. The source of infection was found in 63 (88.7% patients. All the patients had ulcerative lesions, with a central necrosis. Most of the patients (65% had several lesions, mainly located in the upper limbs (80%. Four patients (5.6% developed meningoencephalitis, and three of them eventually died. In conclusion, considering its clinical and epidemiological characteristics, cutaneous anthrax must be included in the differential diagnosis of skin ulcers. A patient with clinical suspicion of the disease should receive effective treatment soon, in order to avoid neurological complications which carry a high fatality rate.El ántrax es una zoonosis producida por el Bacillus anthracis y la infección humana es endémica en diversas partes del mundo, incluyendo el Perú. Más del 95% de las infecciones adquiridas naturalmente son cutáneas y aproximadamente 5% de ellas pueden evolucionar para meningoencefalitis. En este estudio revisamos las características clínicas y epidemiológicas de los pacientes con diagnóstico de ántrax cutáneo evaluados entre 1969 y 2002 en el Hospital Nacional Cayetano Heredia (HNCH y en el Instituto de Medicina Tropical Alexander von Humboldt, en Lima, Per

  5. Effect of Listeria seeligeri or Listeria welshimeri on Listeria monocytogenes detection in and recovery from buffered Listeria enrichment broth.

    Science.gov (United States)

    Dailey, Rachel C; Welch, Lacinda J; Hitchins, Anthony D; Smiley, R Derike

    2015-04-01

    The presence of multiple species of Listeria in regulated food products is not uncommon and can complicate the recovery of Listeria monocytogenes particularly on a non-differentiating medium. The potential complications of Listeria seeligeri and Listeria welshimeri on the recovery of L. monocytogenes from inoculated food test samples using the U.S. Food and Drug Administration's (FDA) selective enrichment procedure was investigated. Post-enrichment enumeration, in the absence of food product, indicates that some L. seeligeri and L. monocytogenes pairings may have population differentials as great as 2.7 ± 0.1 logs with L. seeligeri being the predominant species. A similar observation was noted for L. welshimeri and L. monocytogenes pairings which resulted in population differentials as large as 3.7 ± 0.2 logs with L. welshimeri being the predominant species. Select strain pairings were used to inoculate guacamole, crab meat, broccoli, and cheese with subsequent recovery by the FDA Bacteriological Analytical Manual (BAM) method with 10 colonies per sample selected for confirmation. The presence of L. seeligeri had little effect on the recovery of L. monocytogenes. The presence of L. welshimeri resulted in the failure to recover L. monocytogenes in three out of the four food matrices. This work extends the observation that non-pathogenic species of Listeria can complicate the recovery of L. monocytogenes and that competition during selective enrichment is not limited to the presence of just Listeria innocua. Published by Elsevier Ltd.

  6. Effect of Listeria seeligeri or Listeria welshimeri on Listeria monocytogenes detection in and recovery from buffered Listeria enrichment broth☆

    Science.gov (United States)

    Dailey, Rachel C.; Welch, Lacinda J.; Hitchins, Anthony D.; Smiley, R. Derike

    2016-01-01

    The presence of multiple species of Listeria in regulated food products is not uncommon and can complicate the recovery of Listeria monocytogenes particularly on a non-differentiating medium. The potential complications of Listeria seeligeri and Listeria welshimeri on the recovery of L. monocytogenes from inoculated food test samples using the U.S. Food and Drug Administration's (FDA) selective enrichment procedure was investigated. Post-enrichment enumeration, in the absence of food product, indicates that some L. seeligeri and L. monocytogenes pairings may have population differentials as great as 2.7 ± 0.1 logs with L. seeligeri being the predominant species. A similar observation was noted for L. welshimeri and L. monocytogenes pairings which resulted in population differentials as large as 3.7 ± 0.2 logs with L. welshimeri being the predominant species. Select strain pairings were used to inoculate guacamole, crab meat, broccoli, and cheese with subsequent recovery by the FDA Bacteriological Analytical Manual (BAM) method with 10 colonies per sample selected for confirmation. The presence of L. seeligeri had little effect on the recovery of L. monocytogenes. The presence of L. welshimeri resulted in the failure to recover L. monocytogenes in three out of the four food matrices. This work extends the observation that non-pathogenic species of Listeria can complicate the recovery of L. monocytogenes and that competition during selective enrichment is not limited to the presence of just Listeria innocua. PMID:25475325

  7. Aerosol studies with Listeria innocua and Listeria monocytogenes.

    Science.gov (United States)

    Zhang, Guodong; Ma, Li; Oyarzabal, Omar A; Doyle, Michael P

    2007-08-01

    Aerosol studies of Listeria monocytogenes in food processing plants have been limited by lack of a suitable surrogate microorganism. The objective of this study was to investigate the potential of using green fluorescent protein-labeled strains of Listeria innocua as a surrogate for L. monocytogenes for aerosol studies. These studies were conducted in a laboratory bioaerosol chamber and a pilot food-processing facility. Four strains of L. innocua and five strains of L. monocytogenes were used. In the laboratory chamber study, Listeria cells were released into the environment at two different cell numbers and under two airflow conditions. Trypticase soy agar (TSA) plates and oven-roasted breasts of chicken and turkey were placed in the chamber to monitor Listeria cell numbers deposited from aerosols. A similar experimental design was used in the pilot plant study; however, only L. innocua was used. Results showed that L. monocytogenes and L. innocua survived equally well on chicken and turkey breast meats and TSA plates. No-fan and continuous fan applications, which affected airflow, had no significant effect on settling rates of aerosolized L. monocytogenes and L. innocua in the bioaerosol chamber or L. innocua in the pilot plant study. Listeriae cell numbers in the air decreased rapidly during the first 1.5 h following release, with few to no listeriae detected in the air at 3 h. Aerosol particles with diameters of 1 and 2 microM correlated directly with the number of Listeria cells in the aerosol but not with particles that were 0.3, 0.5, and 5 microM in diameter. Results indicate that L. innocua can be used as a surrogate for L. monocytogenes in an aerosol study.

  8. Symptomatic hydrocephalus in a newborn infected with listeria monocytogenes Hidrocefalia sintomática em um recém-nascido infectado com Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    Analía L. Laciar

    2000-03-01

    Full Text Available Central nervous system infections caused by Listeria monocytogenes produce a wide range of clinical symptoms which include cerebral abscesses, meningitis and nonmeningitic parenchymal cerebritis. A case study is presented of early listeriosis with signs of meningitis accompanied with septicemia and complicated with severe hydrocephalus.As infecções do sistema nervoso central produzidas por Listeria monocytogenes provocam una grande variedade de sintomas clínicos que incluem abscessos cerebrais, meningites e cerebrites parenquimáticas não meningíticas. Apresenta-se um caso de listeriose precoce com sinais de meningite acompanhada de septicemia e agravado com hidrocefalia grave.

  9. Clinical Case of Listeria Meningitis

    Directory of Open Access Journals (Sweden)

    V.O. Kuzmina

    2014-09-01

    Full Text Available This article describes a case of listeria meningitis in a 41-year-old man. At the time of admission to hospital, the patient complained of fever, headache, vomiting, general weakness. An objective examination revealed cervical lymphadenopathy, meningeal signs (positive Kernig’s sign and doubtful rigidity of occipitals, with no focal symptoms. On the right hand it was revealed an abscess in the stage of healing. In the liquor we have detected: pleocytosis — 222 cells with a predominance of neutrophils — 73 %, рrotein — 0.49 g/l, the sugar level in the liquor is slightly reduced. During the bacteriological study of liquor we have isolated Listeria monocytogenes. Serological survey of blood serum using passive hemagglutination test and indirect hemagglutination test revealed levels of antibodies to Listeria monocytogenes — 1 : 800 and 3 (+, respectively.

  10. Listeria Endocarditis: A Diagnostic Challenge

    Directory of Open Access Journals (Sweden)

    Wilhelmina J. A. R. M. Valckx MD

    2017-04-01

    Full Text Available A 74-year-old hemodialysis patient with a history of an atrial septum defect closure, coronary bypass surgery, and a St. Jude aortic prosthetic valve was diagnosed with pneumonia and volume overload. Blood cultures were positive for Listeria monocytogenes, and amoxicillin was given for 2 weeks. Immediately after discontinuation of amoxicillin, fever relapsed. Transthoracic and transesophageal echocardiography showed no sign of endocarditis. Given the fever relapse and 3 positive minor Duke criteria, an 18F-FDG PET-CT scan (18F-fluorodeoxyglucose-positron emission tomography-computed tomography scan was performed. This scan showed activity at the aortic root, proximal ascending aorta, and inferior wall of the heart, making Listeria monocytogenes endocarditis a likely explanation. Amoxicillin was given for 6 weeks with good clinical result. Diagnosing a life-threatening Listeria monocytogenes endocarditis can be challenging and an 18F-FDG PET-CT scan can be helpful.

  11. Listeria monocytogenes Monographic Study

    Directory of Open Access Journals (Sweden)

    Emil Tirziu

    2010-05-01

    Full Text Available Listeria monocytogenes is a ubiquitous bacteria with a remarkable resistance in discordant condition which produce listeriosis, an infectious disease that affects multiple domestic and wild animals’ species, but also humans. Receptive to listeriosis are the majority of domestic or wild mammals and birds, in the last years being registered an increase of receptivity in humans. The concept of listeriosis in human pathology, a disease caused by eating or drinking contaminated food and water, appeared for the first time in 1981, during an outbreak in Canada with seven cases in adults and 34 cases of maternalfetal listeriosis. The alimentary origin of human listeriosis can be easily explained if considered some general characteristics of the bacteria. Thus, resistance in various conditions, especially at lower temperatures, justifies its dissemination and food contamination, particularly when is conserved by refrigeration. Also, L. monocytogenes has a significant presence in alimentary products. Some studies showed that 4% of the milk products, 29% of the meat products, 5% of the vegetable products and 26% of the products obtained from fishes and shell fishes are positive for L. monocytogenes, which allows us to say that battle against these bacteria is a war against microbial contamination.

  12. Detection of Listeria Spp. and Listeria monocytogenes in vegetables ...

    African Journals Online (AJOL)

    This paper aimed to study the prevalence and antibiotic resistance pattern among Listeria monocytogenes in raw vegetables sourced from commercial farms and local farms in Terengganu. Thirteen types of vegetables investigated for the presence of L. monocytogenes using multiplex PCR and LAMP methods. Isolation of ...

  13. First Trimester Listeria monocytogenes Septicemia

    NARCIS (Netherlands)

    Goddijn, M.; Schipper, H. G.; Spanjaard, L.; Wolf, H.

    1997-01-01

    Background: Little is known about fetal outcome after Listeria monocytogenes septicemia in the first trimester of pregnancy.Case: A primigravida with L. monocytogenes septicemia at 9 weeks gestation was treated with amoxicillin. At 40 weeks gestation a healthy female infant was born.Conclusion: This

  14. NATURAL ATYPICAL LISTERIA INNOCUA STRAINS WITH LISTERIA MONOCYTOGENES PATHOGENICITY ISLAND 1 GENES

    Science.gov (United States)

    The detection of the human foodborne pathogen, Listeria monocytogenes, in food, environmental samples and clinical specimens associated with cases of listeriosis, a rare but high mortality-rate disease, requires distinguishing the pathogen from other Listeria species. Speciation...

  15. Las mujeres embarazadas deben saber que la Listeria algunas veces contamina el queso fresco y otros tipos de quesos blandos consumidos en la comunidad hispana (Pregnant women should know that Listeria can sometimes contaminate queso fresco and other soft cheeses consumed in the Hispanic community)

    Centers for Disease Control (CDC) Podcasts

    La epidemióloga Ruth Luna-Gierke, de la División de Enfermedades Transmitidas por los Alimentos, el Agua y el Ambiente de los CDC, habla sobre los peligros de la infección por Listeria o listeriosis durante el embarazo, y sobre cómo el queso fresco y otros tipos de quesos blandos consumidos en la comunidad hispana a veces pueden estar contaminados con Listeria.

  16. Efeito e modo de ação das bacteriocinas produzidas por Lactococcus lactis subsp. lactis ITAL 383, ATCC 11454 e CNRZ 150 contra Listeria innocua LIN 11 Effect and mode of action of the bacterioncin produced by Lactococcus. lactis subsp. lactis ITAL 383, ATCC 11454 e CNRZ 150 against Listeria innocua LIN 11

    Directory of Open Access Journals (Sweden)

    Izildinha MORENO

    1999-01-01

    Full Text Available O efeito e o modo de ação das bacteriocinas produzidas por L. lactis subsp. lactis ITAL 383 e CNRZ 150 são similares à nisina de L. lactis subsp. lactis ATCC 11454. Estas bacteriocinas apresentaram um modo de ação bactericida, causando a lise de células de L. innocua LIN 11, associada ao decréscimo da absorbância e da viabilidade celular. O efeito letal foi maior para células em fase exponencial comparativamente à fase estacionária de crescimento. A adsorção dessas bacteriocinas às células de L. innocua LIN 11 foi muito rápida e influenciada pelo pH do meio de suspensão; adsorção máxima foi verificada a pH 6,0 e logo após o contato inicial. Perda completa de adsorção ocorreu em pH 2,0.The effect and mode of action of the bacteriocin produced by L. lactis subsp. lactis ITAL 383 and CNRZ 150 are similar to the nisin produced by L. lactis subsp. lactis ATCC 11454. It was clearly bactericidal, and caused lysis of a strain of L. innocua LIN 11 detected by the decrease of absorbance values and the cell viability. Their lethal effect was considerably higher during the logarithmic growth when compared to the stationary phase. Adsorption developed rapidly and was influenced by the pH value of the suspension medium. Maximum adsorption was observed at pH 6,0 and immediately after initial contact and loss at pH 2,0.

  17. Listeria species in retail smoked fish at Jos, Nigeria | Chukwu ...

    African Journals Online (AJOL)

    The prevalence of Listeria species in 65 samples of smoked fish at the retail markets in Jos, Nigeria, is reported. The experimental samples which included 30 catfish (Clarias species) and 35 Tilapia were screened for Listeria monocytogenes and other Listeria species using a two-step enrichment method. Total Listeria ...

  18. Patogénesis de Listeria monocytogenes, microorganismo zoonotico emergente

    Directory of Open Access Journals (Sweden)

    Kirvis Torres

    2005-05-01

    Full Text Available Listeria monocytogenes además de ser un paradigma para la investigación inmunológica se ha convertidoen sistema modelo apropiado para el análisis de los mecanismos moleculares del parasitismo intracelularde otras bacterias. Investigadores en el área de la inmunología se interesaron en este microorganismocuando se reconoció el riesgo que representaba para la salud pública y la seguridad en la industria dealimentos. Desde mediados de los años 80’s se ha investigado la biología molecular de los marcadores devirulencia de este microorganismo, la biología celular de las interacciones de los marcadores de virulenciacon los receptores de la célula hospedero, el citoesqueleto, las vías de transducción de señales y losmecanismos de inmunidad mediada por células del hospedero. El propósito de esta revisión es describiralgunas características taxonómicas y filogenéticas de Listeria monocytogenes , la incidencia humana yanimal de varios serotipos, la fisiopatología de la infección , modelos animales y de cultivo celular utilizadospara estudios de virulencia, las poblaciones de riesgo, manifestaciones clínicas de listeriosis humana yanimal, el tratamiento, la organización genética y evolución de los determinantes de virulencia, losmecanismos empleados para interactuar con la célula hospedera, y los mecanismos para escapar de losprocesos de muerte celular y pasar de una célula infectada a otra. La información recopilada resulta degran importancia para el personal de salud, industria, consumidores y población de riesgo; razón por lacual Listeria monocytogenes es un patógeno que representa una amenaza para la salud pública mundial.

  19. Occurrence of Listeria monocytogenes in cheese and ice cream produced in the State of Paraná, Brazil Ocorrência de Listeria monocytogenes em queijos e sorvetes produzidos no Estado do Paraná, Brasil

    Directory of Open Access Journals (Sweden)

    Wanda Moscalewski Abrahão

    2008-06-01

    Full Text Available The occurrence of Listeria monocytogenes in Brazilian ice cream and in some soft and semi-soft cheeses produced and sold in the State of Paraná, Brazil was evaluated. Ninety samples of cheese and sixty samples of ice creams were analyzed following the guidelines outlined by the official institutes, AOAC and FDA. In the ice cream samples no isolation of Listeria spp. was found. The percentage of these ninety samples of cheeses positive for Listeria spp. was 12.20%. Listeria monocytogenes was detected in six (6.70% of the same samples. The presence of Listeria innocua was five (5.50% in the samples analyzed was also observed. According to the results of the work it is possible to presume that there is a potential health risk to the brazilian population, heightened by aging and the increase in immunodepressed. These results indicate the need for the implementation of monitoring of these microorganisms as much by producers as by health inspectors. The results also show that the VIP (visual immunoprecipitation assay is a viable triage method of contaminated samples for the liberation of products for commercialization, as it is quick, reliable and does not require additional equipment other than that normally found in production labs, while presenting reliable results.A ocorrência de Listeria monocytogenes em sorvetes e alguns tipos de queijos macios e semi-macios produzidos e vendidos no Estado do Paraná Brasil foram avaliados. Noventa amostras de queijo e sessenta amostras de sorvete foram analisadas seguindo os protocolos da AOAC e FDA. Nas amostras de sorvete, não ocorreu o isolamento de Listeria spp. Foi detectada Listeria spp em 12,20% de amostras de queijo, das quais 6 (6,70% foram positivas para Listeria monocytogenes. Foi também observada a presença de Listeria innocua em 5 amostras (5,50% das mesmas amostras. Pelos resultados deste trabalho pode-se pressupor que existe um risco potencial à saúde da população brasileira com o

  20. Prevalence of Listeria monocytogenes in poultry meat

    Directory of Open Access Journals (Sweden)

    Mehmet ELMALI

    2015-01-01

    Full Text Available AbstractThe objectives of this study were i to isolate Listeria spp. and Listeria monocytogenes in broiler wing meat samples, ii to confirm the isolates by PCR, based on prs and hly A gene sequences, iii to determine the seasonal and monthly distribution of the isolates. A total of 120 broiler wing meat samples (60 packaged pieces wrapped using strech film in styrofoam plates and 60 unpackaged pieces bought from different markets in Hatay province were analysed. Listeria spp. was isolated from 57 (47.5% out of 120 samples. Fifty-four, out of 57 Listeria spp. isolates were identified as L. monocytogenes. L. monocytogenes was isolated from the samples collected during the spring, winter, summer, and autumn at the levels of 26.6%, 40%, 53.3%, 60%, respectively. In this study, the isolation rates were found to be the highest in autumn, while the isolation rates were found to be the lowest in spring. As a consequence, high prevalence of Listeria spp. and L. monocytogenes in poultry wing meat samples may pose a risk for human health. We consider that with obeying the rules of good hygiene practices (GHP, good manufacturing practices (GMP and HACCP can minimize the contamination with Listeria spp.

  1. Relationship between Listeria monocytogenes and Listeria spp. in seafood processing plants.

    Science.gov (United States)

    Alali, Walid Q; Schaffner, Donald W

    2013-07-01

    The objective of this study was to evaluate the relationship between prevalence of Listeria monocytogenes as an outcome and Listeria spp. as an explanatory variable by food products, food contact surfaces, and nonfood contact surfaces in seafood processing plants by using peer-reviewed published data. Nine sets of prevalence data of L. monocytogenes and Listeria spp. were collected from published studies and used for the analyses. Based on our analysis, the relationship between L. monocytogenes prevalence and Listeria spp. prevalence in food products (incoming raw materials and finish products) was significant (P = 0.04) with (low) R² = 0.36. Furthermore, Listeria spp. were not a good indicator for L. monocytogenes when testing food contact surfaces (R² = 0.10). Listeria spp. were a good indicator for L. monocytogenes only on nonfood contact surfaces (R² = 0.90). On the other hand, the presence of Listeria spp. on food contact surfaces (R² = 0.002) and nonfood contact surfaces (R² = 0.03) was not a good indicator for L. monocytogenes presence in food products. In general, prevalence of Listeria spp. does not seem to be a good indicator for L. monocytogenes prevalence in seafood processing plants.

  2. Listeria monocytogenes endophthalmitis following keratoconjunctivitis.

    Science.gov (United States)

    Shoughy, Samir S; Tabbara, Khalid F

    2014-01-01

    Endophthalmitis due to endogenous or exogenous bacteria is a rare infection of the eye. We report a case of endophthalmitis following Listeria monocytogenes keratoconjunctivitis in a 27-year-old healthy white male presenting with hand motion visual acuity, right eye mucopurulent conjunctivitis, elevated intraocular pressure, and pigmented hypopyon 6 months post-keratectomy. The conjunctivitis was unresponsive to a 5-day course of topical tobramycin eye drops, and the patient developed keratitis with pain that progressed to endophthalmitis after 21 days. Diagnostic B-scan revealed vitreous exudates. Intraocular fluid specimen showed Gram-positive organisms and the aqueous culture grew penicillin-/aminoglycoside-sensitive L. monocytogenes. The patient was given intravitreal and systemic vancomycin and ceftazidime. The eye was unresponsive to intravenous penicillin and gentamicin; the anterior chamber progressively flattened and developed phthisis bulbi. L. monocytogenes keratoconjunctivitis may lead to bacterial endophthalmitis. Prompt culture and early antibiotic therapy are recommended.

  3. Prevalence of Listeria species in some foods and their rapid ...

    African Journals Online (AJOL)

    Results: Out of 40 meat samples, 14 (35 %) samples were contaminated with Listeria spp., with the ... Conclusion: High protein foods contain different types of Listeria species; whole-cell protein ..... in meat and fermented fish in Malaysia.

  4. Las mujeres embarazadas deben saber que la listeria algunas veces contamina el queso fresco y otros tipos de quesos blandos consumidos en la comunidad hispana

    Centers for Disease Control (CDC) Podcasts

    2013-10-28

    La epidemióloga Ruth Luna-Gierke, de la División de Enfermedades Transmitidas por los Alimentos, el Agua y el Ambiente de los CDC, habla sobre los peligros de la infección por Listeria o listeriosis durante el embarazo, y sobre cómo el queso fresco y otros tipos de quesos blandos consumidos en la comunidad hispana a veces pueden estar contaminados con Listeria.  Created: 10/28/2013 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 10/28/2013.

  5. Detection of Listeria in raw milk in Syria

    International Nuclear Information System (INIS)

    Al-Mariri, A.; Abou-Younes, A.

    2010-01-01

    The 66 milk collected from all province of Syria, were examined for the presence of Listeria sp. using a several technique, and L. monocytogenes serotypes associated with human listeriosis were also identified in the product. The PCR based method identified 117 strains of Listeria, L. monocytogenes, L. innocua, L. ivanovii, L. gravi, and L. welshimeri. The API Listeria system identified 94% of the isolates whereas FTIR identification was 98% for all Listeria species. (author)

  6. Formulacio?n de mezclas de aceites esenciales como inhibidores de Listeria monocytogenes

    OpenAIRE

    Cazar R., Mari?a-Elena

    2013-01-01

    Las enfermedades causadas por el consumo de alimentos contaminados tienen un alto impacto econo?mico y en la salud pu?blica. Las contaminaciones de alimentos causadas por pato?genos como Campylobacter y Salmonella son las ma?s comu?nmente reportadas. No obstante, pato?genos como Listeria monocytogenes pueden adaptarse, sobrevivir y crecer en un amplio rango de condiciones ambientales, causando patologi?as con elevadas tasas de hospitalizacio?n y mortalidad (Gandhi y Chikindas,2007). Las in...

  7. Prevalence of Listeria species in camel sausages from retail markets in Aydin province in Turkey and RAPD analysis of Listeria monocytogenes isolates

    OpenAIRE

    Ozbey, Gokben; Ertas, Hasan Basri; Kok, Filiz

    2006-01-01

    Abstract Samples were taken from 100 camel sausages from the different retail markets in Aydin province in the south-west of Turkey and they were tested for the presence of Listeria spp by biochemical methods. Samples were enriched using Listeria Enrichment Broth and they were inoculated onto Listeria Selective Agar. Listeria monocytogenes was isolated from nine samples (9%), Listeria innocua from 14 samples (14%) and Listeria welshimeri from two samples(2%). A 701 bp fragment of listeriolysi...

  8. FRECUENCIA DE Listeria spp., EN QUESOS COLOMBIANOS COSTEÑOS

    Directory of Open Access Journals (Sweden)

    Janneth Gallegos.

    2007-12-01

    Full Text Available Objetivo. Determinar la frecuencia de Listeria spp., en quesos frescos costeños, distribuidos en plazas de mercado populares de las ciudades de Montería y Cereté. Materiales y métodos. Teniendo en cuenta la importancia económica de esta zona ganadera para Colombia se tomaron 217 muestras entre Junio y Agosto de 2005, los aislamientos obtenidos fueron identificados por pruebas bioquímicas presuntivas, PCRMúltiple (L1-U1/LF-LR y pruebas bioquímicas para confirmación de especie. Adicionalmente, se determinó la frecuencia de las especies del género y se caracterizó la resistencia antimicrobiana de las cepas de mayor frecuencia. Resultados. Las pruebas bioquímicas y la PCR detectaron 49 aislamientos positivos para Listeria (22.58%, de los cuales 16.33% (8/49 correspondieron a Montería y 24.40% (41/168 a Cereté. La frecuencia por especies fue 14.75% para L. ivanovii, 2.30% para L. innocua, 1.84% para L. welshimeri y 1.38% para L. seeligeri, no se detectó L. monocytogenes. Sólo 3/32 cepas de L. ivanovvi (9.38% mostraron resistencia a penicilina, estreptomicina y eritromicina respectivamente. Conclusiones. Los resultados confirman que los quesos costeños están frecuentemente contaminados con Listeria spp. La presencia de L. ivanovii patógeno involucrado en algunos casos de infecciones oportunistas en humanos y L. innocua; microorganismo utilizado en muchas industrias de alimento como indicador del grado o calidad de sanitización; demuestra que las condiciones de producción y expendio no son adecuadas y que el consumo de queso costeño no es seguro. La resistencia antimicrobiana aunque baja muestra posibilidades para la transmisión horizontal y/o vertical de los genes de resistencia.

  9. Listeria monocytogenes endophthalmitis following keratoconjunctivitis

    Directory of Open Access Journals (Sweden)

    Shoughy SS

    2014-01-01

    Full Text Available Samir S Shoughy,1 Khalid F Tabbara1–31The Eye Center and The Eye Foundation for Research in Ophthalmology, Riyadh, Saudi Arabia; 2Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia; 3The Wilmer Ophthalmological Institute of The Johns Hopkins University School of Medicine, Baltimore, MD, USAAbstract: Endophthalmitis due to endogenous or exogenous bacteria is a rare infection of the eye. We report a case of endophthalmitis following Listeria monocytogenes keratoconjunctivitis in a 27-year-old healthy white male presenting with hand motion visual acuity, right eye mucopurulent conjunctivitis, elevated intraocular pressure, and pigmented hypopyon 6 months post-keratectomy. The conjunctivitis was unresponsive to a 5-day course of topical tobramycin eye drops, and the patient developed keratitis with pain that progressed to endophthalmitis after 21 days. Diagnostic B-scan revealed vitreous exudates. Intraocular fluid specimen showed Gram-positive organisms and the aqueous culture grew penicillin-/aminoglycoside-sensitive L. monocytogenes. The patient was given intravitreal and systemic vancomycin and ceftazidime. The eye was unresponsive to intravenous penicillin and gentamicin; the anterior chamber progressively flattened and developed phthisis bulbi. L. monocytogenes keratoconjunctivitis may lead to bacterial endophthalmitis. Prompt culture and early antibiotic therapy are recommended.Keywords: conjunctivitis, L. monocytogenes, endophthalmitis

  10. Listeria Occurrence in Poultry Flocks: Detection and Potential Implications

    Directory of Open Access Journals (Sweden)

    Michael J. Rothrock

    2017-08-01

    Full Text Available Foodborne pathogens such as Salmonella, Campylobacter, Escherichia coli, and Listeria are a major concern within the food industry due to their pathogenic potential to cause infection. Of these, Listeria monocytogenes, possesses a high mortality rate (approximately 20% and is considered one of the most dangerous foodborne pathogens. Although the usual reservoirs for Listeria transmission have been extensively studied, little is known about the relationship between Listeria and live poultry production. Sporadic and isolated cases of listeriosis have been attributed to poultry production and Listeria spp. have been isolated from all stages of poultry production and processing. Farm studies suggest that live birds may be an important vector and contributor to contamination of the processing environment and transmission of Listeria to consumers. Therefore, the purpose of this review is to highlight the occurrence, incidence, and potential systemic interactions of Listeria spp. with poultry.

  11. Listeria Occurrence in Poultry Flocks: Detection and Potential Implications.

    Science.gov (United States)

    Rothrock, Michael J; Davis, Morgan L; Locatelli, Aude; Bodie, Aaron; McIntosh, Tori G; Donaldson, Janet R; Ricke, Steven C

    2017-01-01

    Foodborne pathogens such as Salmonella, Campylobacter, Escherichia coli , and Listeria are a major concern within the food industry due to their pathogenic potential to cause infection. Of these, Listeria monocytogenes , possesses a high mortality rate (approximately 20%) and is considered one of the most dangerous foodborne pathogens. Although the usual reservoirs for Listeria transmission have been extensively studied, little is known about the relationship between Listeria and live poultry production. Sporadic and isolated cases of listeriosis have been attributed to poultry production and Listeria spp. have been isolated from all stages of poultry production and processing. Farm studies suggest that live birds may be an important vector and contributor to contamination of the processing environment and transmission of Listeria to consumers. Therefore, the purpose of this review is to highlight the occurrence, incidence, and potential systemic interactions of Listeria spp. with poultry.

  12. Non-Specific Reactions during Immunomagnetic Separation of Listeria

    Directory of Open Access Journals (Sweden)

    Iveta Zachová

    2005-01-01

    Full Text Available Problems occurring during the immunomagnetic separation (IMS of Listeria using immunomagnetic particles Dynabeads® anti-Listeria (Dynal Biotech, Norway were specified. Characteristics of these particles were compared with anti-Listeria spp. magnetite particles (Quantum Magnetics, USA. Pure cultures of Listeria innocua, Arthrobacter spp., Bacillus subtilis, Citrobacter braakii, Escherichia coli, Enterobacter aerogenes, Enterobacter cloacae and Staphylococcus aureus were used to evaluate non-specific reactions during IMS. Gram-positive microorganisms, especially Staphylococcus aureus and Arthrobacter spp., were found to be responsible for non-specific reactions in most cases. The capacity of Dynabeads® anti-Listeria particles was determined to be about 10 % of the initial pure cultures of Listeria spp., after 10 min of incubation. Non-specific reactions during IMS of Listeria were examined on the artificially inoculated food samples in which Gram-positive bacteria showed the highest percentage of capture. Influence of washing in two buffers was also studied.

  13. Effekt av ulike desinfeksjonsstrategier mot Listeria monocytogenes

    OpenAIRE

    Fossmo, Sabine

    2013-01-01

    Kontroll med bakterier som Listeria utgjør en stor utfordring for mange matprodusenter. Listeria monocytogenes er hovedsakelig et produksjonshygienisk problem, forbedret hygiene kan derfor være tiltak for å redusere overlevelse og smitteoverføring av bakterien i produksjonsmiljø. Hensikten med forsøkene i oppgaven var å undersøke effekten av ulike desinfeksjonsstrategier på drap av L. monocytogenes, både når bakteriene var i biofilm og i suspensjon. Dette inkluderte bruk av tradisjonelle desi...

  14. Camembert, Listeria and the immunocompromised patient.

    Science.gov (United States)

    Ries, F; Dicato, M; Hemmer, R; Arendt, F

    1990-01-01

    Listeriosis is a rare but well known infectious complication in pregnant women and immunocompromised patients. Epidemiological studies have shown an association between listeriosis and alimentary contamination by listeria of a variety of foodstuff including soft, ripened cheeses. We describe two case-reports of listeria meningitis with high evidence of food-related illness due to the consumption of contaminated camembert. These observations urged our State Department of Health to formulate a communication about alimentary listeriosis at the intent of all health care professionals, including recommendations for patients at risk.

  15. Listeria booriae sp. nov. and Listeria newyorkensis sp. nov., from food processing environments in the USA.

    Science.gov (United States)

    Weller, Daniel; Andrus, Alexis; Wiedmann, Martin; den Bakker, Henk C

    2015-01-01

    Sampling of seafood and dairy processing facilities in the north-eastern USA produced 18 isolates of Listeria spp. that could not be identified at the species-level using traditional phenotypic and genotypic identification methods. Results of phenotypic and genotypic analyses suggested that the isolates represent two novel species with an average nucleotide blast identity of less than 92% with previously described species of the genus Listeria. Phylogenetic analyses based on whole genome sequences, 16S rRNA gene and sigB gene sequences confirmed that the isolates represented by type strain FSL M6-0635(T) and FSL A5-0209 cluster phylogenetically with Listeria cornellensis. Phylogenetic analyses also showed that the isolates represented by type strain FSL A5-0281(T) cluster phylogenetically with Listeria riparia. The name Listeria booriae sp. nov. is proposed for the species represented by type strain FSL A5-0281(T) ( =DSM 28860(T) =LMG 28311(T)), and the name Listeria newyorkensis sp. nov. is proposed for the species represented by type strain FSL M6-0635(T) ( =DSM 28861(T) =LMG 28310(T)). Phenotypic and genotypic analyses suggest that neither species is pathogenic. © 2015 IUMS.

  16. Antimicrobial resistance of Listeria monocytogenes and Listeria innocua from meat products and meat-processing environment.

    Science.gov (United States)

    Gómez, Diego; Azón, Ester; Marco, Noelia; Carramiñana, Juan J; Rota, Carmina; Ariño, Agustín; Yangüela, Javier

    2014-09-01

    A total of 336 Listeria isolates from ready-to-eat (RTE) meat products and meat-processing environments, consisting of 206 Listeria monocytogenes, and 130 Listeria innocua isolates, were characterized by disc diffusion assay and minimum inhibitory concentration (MIC) values for antimicrobial susceptibility against twenty antimicrobials. Resistance to one or two antimicrobials was observed in 71 L. monocytogenes isolates (34.5%), and 56 L. innocua isolates (43.1%). Multidrug resistance was identified in 24 Listeria isolates, 18 belonging to L. innocua (13.9%) and 6 to L. monocytogenes (2.9%). Oxacillin resistance was the most common resistance phenotype and was identified in 100% Listeria isolates. A medium prevalence of resistance to clindamycin (39.3% isolates) and low incidence of resistance to tetracycline (3.9% isolates) were also detected. Listeria isolates from RTE meat products displayed higher overall antimicrobial resistance (31.3%) than those from the environment (13.4%). All the strains assayed were sensitive to the preferred antibiotics used to treat listeriosis. Results showed that although antimicrobial resistance in L. monocytogenes still occurs at a low prevalence, L. innocua can form a reservoir of resistance genes which may transfer between bacterial species, including transference to organisms capable of causing disease in humans. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Infecciones fúngicas emergentes: fungemia por Sporobolomyces salmonicolor. Reporte de un caso Emerging fungal infections: Sporobolomyces salmonicolor fungemia. Case Report

    Directory of Open Access Journals (Sweden)

    Adriana Paola Franco Rodríguez

    2010-12-01

    Full Text Available En los últimos años, la emergencia de infecciones por hongos se ha dado en parte por el aumento en las infecciones por microrganismos que normalmente no son patógenos. El siguiente reporte describe la fungemia y meningoencefalitis por Sporobolomyces salmonicolor, una levadura frecuente en el medio ambiente y las plantas, en un paciente sin factores de riesgo conocidos, con desenlace fatal a pesar del manejo con antifúngicos. Este caso nos recuerda que dentro de las infecciones micóticas emergentes se encuentra el S. salmonicolor y se debe tener en cuenta dentro del diagnóstico diferencial de levaduras en sangre, como causa infrecuente, potencialmente mortal.The emergence of pathogens, mainly fungi, in recent years has been partly due to overappearance of organisms that normally are not pathogenic in humans. The following report describes Sporobolomyces salmonicolor fungaemia and proven meningoencephalitis in a patient not showing risk factors who suffers a fatal outcome despite management with antifungal agents. The said yeast lives mainly in tree environments and plants. This case reminds us that there is S. salmonicolor within the emerging fungal infections, and this fact should be taken into account in the differential diagnosis of yeasts in blood as a rare and lifethreatening cause.

  18. Disinfectant effect of Methylated Ethanol against Listeria species

    Directory of Open Access Journals (Sweden)

    Y Yakubu

    2012-04-01

    Full Text Available This study was carried out in order to determine the disinfectant effect of Methylated spirit® (95% methanol and 5% ethanol as a teat dip against Listeria species. Hand milking was employed to collect 576 (288 x 2 raw milk samples from different lactating cows within Sokoto metropolis (Nigeria. 288 samples were collected before disinfecting the udder teats with Methylated spirit®, while the other 288 were collected after disinfection with Methylated spirit®. The samples were analyzed using selective culture and isolation technique in which the 288 samples collected before disinfection, 114 (39.6% were positive for Listeria species. Among the positive samples 44 (38.6% were Listeria innocua, 16 (14.0% Listeria ivanovii, 36 (31.6% Listeria monocytogenes, 11 (9.6% Listeria welshimeri and 7 (6.1% Listeria seeligeri, while none of the 288 samples collected after disinfection was positive. The study has shown high prevalence of Listeria species in milk collected without washing/disinfecting the teats and has also established the sensitivity of Listeria species to methylated ethanol which can be used as dip for disinfecting udder teats before milking in order to prevent contamination with Listeria species and other methylated spirit-sensitive organisms. This study is essential to educate Fulani herdsmen and other milk handlers on the importance of disinfecting udder teats before milking. [Vet. World 2012; 5(2.000: 91-93

  19. LACTIC FLORA-LISTERIA MONOCYTOGENES INTERACTION

    Directory of Open Access Journals (Sweden)

    S. Colombo

    2012-08-01

    Full Text Available The EC Regulation 2073/2005 (1 requires that food processors evaluate the capability of ready-to-use (RTE products to support the development of Listeria monocytogenes when their pH and aW values are favourable to the growth of this microorganism. It is renown that the lactic flora plays an important role in many different foods, both from a technological and a food safety standpoint. This study was aimed to observe the behaviour and the potential anti-Listeria effect of some natural lactic flora present in Italian liver patè crostini (chicken heart and liver, anchovies, onions, capers, starch, no added preservatives through the Combase Predictor – Max Growth Rate predictive software. The natural lactic flora of the crostini demonstrated a variable capability to inhibit the growth of Listeria monocytogenes which depends upon : the concentration of the lactic flora at the beginning of the shelf life period and the subsequent lag phase, the possible release of anti-Listeria substances, and the maximum growth rate.

  20. Keep Listeria Out of Your Kitchen

    Science.gov (United States)

    ... Listeria has been linked to a variety of ready-to-eat foods, including deli meats, hot dogs, smoked seafood and ... to check the temperature there. Use precooked and ready-to-eat foods as soon as you can. The longer they ...

  1. Prevalence, antimicrobial resistance profiles of Listeria ...

    African Journals Online (AJOL)

    Listeria monocytogenes is known to cause epidemic and sporadic cases of listeriosis. The present study investigated the occurrence, antibiograms and molecular serotypes of the organism in various retail outlets in Gaborone, Botswana. Food samples were obtained randomly from selected supermarkets and street vendors ...

  2. Control options for Listeria monocytogenes in seafoods

    DEFF Research Database (Denmark)

    Huss, Hans Henrik; Jørgensen, Lasse Vigel; Vogel, Birte Fonnesbech

    2000-01-01

    At least three outbreaks of listeriosis associated with seafood have been reported. Listeria monocytogenes is widely distributed in the general environment including fresh water, coastal water and live fish from these areas. Contamination or recontamination of seafood may also take place during...

  3. Listeria monocytogenes : nog steeds een probleem?

    NARCIS (Netherlands)

    Beumer, R.R.

    2011-01-01

    Listeria monocytogenes is net als vele andere bacteriële voedselpathogenen al tientallen jaren bekend. De meeste grondstoffen voor voedingsmiddelen komen uit de akker- en tuinbouw, de veehouderij en de visserij. Besmetting vindt daar plaats met micro-organismen afkomstig uit grond, fecaliën, water,

  4. Longitudinal monitoring of Listeria monocytogenes and Listeria phages in seafood processing environments in Thailand.

    Science.gov (United States)

    Vongkamjan, Kitiya; Benjakul, Soottawat; Kim Vu, Hue Thi; Vuddhakul, Varaporn

    2017-09-01

    Listeria monocytogenes is a foodborne pathogen commonly found in environments of seafood processing, thus presenting a challenge for eradication from seafood processing facilities. Monitoring the prevalence and subtype diversity of L. monocytogenes together with phages that are specific to Listeria spp. ("Listeria phages") will provide knowledge on the bacteria-phage ecology in food processing plants. In this work, a total of 595 samples were collected from raw material, finished seafood products and environmental samples from different sites of a seafood processing plant during 17 sampling visits in 1.5 years of study. L. monocytogenes and Listeria spp. (non-monocytogenes) were found in 22 (3.7%) and 43 (7.2%) samples, respectively, whereas 29 Listeria phages were isolated from 9 (1.5%) phage-positive samples. DNA fingerprint analysis of L. monocytogenes isolates revealed 11 Random Amplified Polymorphic DNA (RAPD) profiles, with two subtypes were frequently observed over time. Our data reveal a presence of Listeria phages within the same seafood processing environments where a diverse set of L. monocytogenes subtypes was also found. Although serotype 4b was observed at lower frequency, data indicate that isolates from this seafood processing plant belonged to both epidemiologically important serotypes 1/2a and 4b, which may suggest a potential public health risk. Phages (all showed a unique genome size of 65 ± 2 kb) were classified into 9 host range groups, representing both broad- and narrow-host range. While most L. monocytogenes isolates from this facility were susceptible to phages, five isolates showed resistance to 12-20 phages. Variations in phage host range among Listeria phages isolated from food processing plant may affect a presence of a diverse set of L. monocytogenes isolates derived from the same processing environment in Thailand. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. NMP DE Listeria sp. EM AFLUENTES E EFLUENTES DE MATADOUROS FRIGORÍFICOS DE BOVINOS EM GOIÁS COUNT OF Listeria sp. IN BOVINE SLAUGHTERHOUSES WASTEWATERS OF GOIÁS

    Directory of Open Access Journals (Sweden)

    César Augusto Garcia

    2007-09-01

    Full Text Available

    140 amostras de afluentes e efluentes de matadouros frigoríficos da cidade de Goiânia - GO, foram analisados com vistas a avaliar o grau de eficiência dos sistemas de tratamento de efluentes, tomando como referência o microrganismo Listeria sp., além de se quantificar este microrganismo. Através da técnica de NMP (Número Mais Provável concluiu-se que as indústrias já captavam água contaminada por Listeria sp. e que o sistema de tratamento de efluentes utilizado não demonstrou eficiência com relação a este microrganismo.

    One hundred and forty portions of slaughterhouses wastewaters in Goiânia-GO, BRAZIL, were analysed for efficacy of effluents treatment system to Listeria sp. and to count this microorganism. With NMP method were concluded, between others answers, that slaughterhouses received water with Listeria sp., and that effluents treatment system doesn’t had efficacy to these bacteria.

  6. Efficacy of a variety of disinfectants against Listeria spp.

    OpenAIRE

    Best, M; Kennedy, M E; Coates, F

    1990-01-01

    The efficacy of 14 disinfectants against Listeria innocua and two strains of Listeria monocytogenes in the presence of organic matter was studied. Quantitative efficacy tests were used. Many of the disinfectants tested were not as effective on Listeria spp. when the test organisms were dried onto the surface of steel disks (carrier tests) as they were when the organisms were placed in suspension (suspension test). The presence of whole serum and milk (2% fat) further reduced the disinfectant ...

  7. Prevalence of Listeria monocytogenes in raw milk in North Lebanon

    International Nuclear Information System (INIS)

    Al Kassaa, I; El Omari, Kh.; Esmail, B.; Hamze, M; Saati, M.

    2016-01-01

    Listeriosis, although a zoonosis, is an invasive disease that can affect newborns, pregnant women and immunocompromised adults. Clinical manifestations can be expressedby febrile gastroenteritis, invasive forms including severe sepsis, meningitis, rhombencephalitis, prenatal infections and abortions. Species of Listeria bacteria are ubiquitous and adaptableto the environment in animal and plant foods. This study aimed to determine the prevalence of Listeria monocytogenes in 100 samples of fresh cow milk collected from different areas of North Lebanon. Listeria monocytogenes was detected by using the Grand VIDAS technique (Biomérieux France). The results obtained revealed the absence of Listeria monocytogenes inall analyzed samples. (Author)

  8. Virulencia de cepas de Listeria monocytogenes procedentes de cabras y sus derivados

    OpenAIRE

    Guicela Ramírez Bernal; Alma Virginia Lara Sagahón; Carlos Gerardo García Tovar; Efrén Díaz Aparicio; Víctor Rubén Tenorio Gutiérrez

    2014-01-01

    Se evaluó la virulencia de cepas de Listeria monocytogenes todas de serotipo 4b procedentes de cabras y sus derivados. Se observaron niveles de virulencia variables cuando se comparó la virulencia relativa (porcentaje de letalidad) en ratones BALB/c inoculados vía intravenosa o intragástrica y su capacidad para infectar macrófagos J774A.1, y células epiteliales Caco-2. Dos cepas obtenidas de alimento de cabras produjeron 100 % de letalidad por ambas vías de inoculación y no mostraron diferenc...

  9. Epidemiologia molecular de Listeria monocytogenes isoladas de diferentes fontes no Brasil

    OpenAIRE

    Andrea Micke Moreno; Renata Paixão; Luisa Zanolli Moreno; Débora Dirani Sena de Gobbi; Daniele Cristine Raimundo; Thais Sebastiana Porfida Ferreira; Ernesto Hofer; Maria Helena Matte; Marina Moreno

    2013-01-01

    Listeria monocytogenes é um importante patógeno de origem alimentar que afeta principalmente grávidas, neonatos, idosos e indivíduos imunocomprometidos, e pode causar abortamento, septicemia e meningite. Dos 13 grupos capsulares descritos, os sorotipos 4b, 1/2b e 1/2a são os mais relacionados à infecção humana. Por esta razão, a sorotipagem possui valor limitado como ferramenta epidemiológica e, dessa forma, métodos mais discriminatórios são necessários para melhorar o conhecimento sobre a co...

  10. Prevalence and Characterization of Listeria Species from Raw Milk and Dairy Products from Çanakkale Province

    Directory of Open Access Journals (Sweden)

    Pınar Şanlıbaba

    2018-02-01

    Full Text Available The objective of this study was to determine the prevalence of Listeria species, specifically Listeria monocytogenes, in raw milk, pasteurized milk, white cheese, and homemade cheese. A total of 200 food samples were collected and analyzed to examine the presence of Listeria spp. The EN ISO 11290-1 method was used for isolation of Listeria. API Listeria test kit was used for biochemically characterization. Listeria spp. were isolated in 25 of the 200 samples (12.5%. The largest number of Listeria spp. was detected in homemade cheese (24%, followed by raw milk (18%, and white cheese (8%. Listeria spp. were not isolated from the pasteurized milk. The most common species isolated were Listeria innocua (5.5%; the remaining Listeria isolates were Listeria ivanovi (3.5%, Listeria welshimeri (3%, and Listeria monocytogenes (0.5%. Listeria monocytogenes was detected in only raw milk.

  11. Fødevarebetinget listeria monocytogenes endokarditis

    DEFF Research Database (Denmark)

    Frydland, Martin; Bundgaard, Henning; Moser, Claus

    2014-01-01

    Infection with Listeria monocytogenes is rare and mainly seen in immunosuppressed patients. Infection with L. monocytogenes has a mortality rate of 30%. We present a case report of L. monocytogenes bacteraemia and endocarditis in a 70-year-old man with several co-morbidities and following four...... major surgical procedures. This illustrates the findings and characteristics in one of the 16 patients who died in 2013 and 2014 this summer due to sausage-related L. monocytogenes infection....

  12. A PNPase Dependent CRISPR System in Listeria

    Science.gov (United States)

    Sesto, Nina; Touchon, Marie; Andrade, José Marques; Kondo, Jiro; Rocha, Eduardo P. C.; Arraiano, Cecilia Maria; Archambaud, Cristel; Westhof, Éric; Romby, Pascale; Cossart, Pascale

    2014-01-01

    The human bacterial pathogen Listeria monocytogenes is emerging as a model organism to study RNA-mediated regulation in pathogenic bacteria. A class of non-coding RNAs called CRISPRs (clustered regularly interspaced short palindromic repeats) has been described to confer bacterial resistance against invading bacteriophages and conjugative plasmids. CRISPR function relies on the activity of CRISPR associated (cas) genes that encode a large family of proteins with nuclease or helicase activities and DNA and RNA binding domains. Here, we characterized a CRISPR element (RliB) that is expressed and processed in the L. monocytogenes strain EGD-e, which is completely devoid of cas genes. Structural probing revealed that RliB has an unexpected secondary structure comprising basepair interactions between the repeats and the adjacent spacers in place of canonical hairpins formed by the palindromic repeats. Moreover, in contrast to other CRISPR-Cas systems identified in Listeria, RliB-CRISPR is ubiquitously present among Listeria genomes at the same genomic locus and is never associated with the cas genes. We showed that RliB-CRISPR is a substrate for the endogenously encoded polynucleotide phosphorylase (PNPase) enzyme. The spacers of the different Listeria RliB-CRISPRs share many sequences with temperate and virulent phages. Furthermore, we show that a cas-less RliB-CRISPR lowers the acquisition frequency of a plasmid carrying the matching protospacer, provided that trans encoded cas genes of a second CRISPR-Cas system are present in the genome. Importantly, we show that PNPase is required for RliB-CRISPR mediated DNA interference. Altogether, our data reveal a yet undescribed CRISPR system whose both processing and activity depend on PNPase, highlighting a new and unexpected function for PNPase in “CRISPRology”. PMID:24415952

  13. ISG15 counteracts Listeria monocytogenes infection

    Science.gov (United States)

    Radoshevich, Lilliana; Impens, Francis; Ribet, David; Quereda, Juan J; Nam Tham, To; Nahori, Marie-Anne; Bierne, Hélène; Dussurget, Olivier; Pizarro-Cerdá, Javier; Knobeloch, Klaus-Peter; Cossart, Pascale

    2015-01-01

    ISG15 is an interferon-stimulated, linear di-ubiquitin-like protein, with anti-viral activity. The role of ISG15 during bacterial infection remains elusive. We show that ISG15 expression in nonphagocytic cells is dramatically induced upon Listeria infection. Surprisingly this induction can be type I interferon independent and depends on the cytosolic surveillance pathway, which senses bacterial DNA and signals through STING, TBK1, IRF3 and IRF7. Most importantly, we observed that ISG15 expression restricts Listeria infection in vitro and in vivo. We made use of stable isotope labeling in tissue culture (SILAC) to identify ISGylated proteins that could be responsible for the protective effect. Strikingly, infection or overexpression of ISG15 leads to ISGylation of ER and Golgi proteins, which correlates with increased secretion of cytokines known to counteract infection. Together, our data reveal a previously uncharacterized ISG15-dependent restriction of Listeria infection, reinforcing the view that ISG15 is a key component of the innate immune response. DOI: http://dx.doi.org/10.7554/eLife.06848.001 PMID:26259872

  14. REALIS: Postgenomic Analysis of Listeria Monocytogenes

    Directory of Open Access Journals (Sweden)

    The REALIS Consortium

    2006-04-01

    Full Text Available Listeria monocytogenes is a remarkably successful food-borne pathogen. It is capable a of surviving and proliferating under conditions that exist within the food chain, such as at low temperatures, high salt and low pH and b of colonizing animal host tissues after ingestion of contaminated food, causing opportunistic infections mainly, but not exclusively, in immunocompromised hosts. The ultimate goals of REALIS are two fold: Firstly, it aims to completely decipher all genes required for survival in and adaptation of Listeria monocytogenes to two very different environments, ie., the infected host and the external environment. Secondly, using genomics and postgenomic tools, REALIS seeks to precisely address fundamental questions regarding evolutionary relationships between pathogenic and non-pathogenic Listeria and to define qualities of particularly successful clonal pathovariants in causing disease. This project will provide both industry and health care managers with rational approaches to curbing food-borne contamination, minimising risks of infection and providing novel pharmacological approaches for halting the fulminant course of infection.

  15. Listeria spp. e listeria monocytogenes na produção de salsichas tipo hot dog

    OpenAIRE

    Cesar, Alessandra Paro Rodrigues; Mesquita, Albenones José de; Prado, Cristiano Sales; Nunes, Iolanda Aparecida; Almeida Filho, Edivaldo Sampaio de

    2011-01-01

    v. 12, n. 2, p.339-352, abr./jun.2011. Listeria monocytogenes está amplamente distribuída no ambiente e tem sido isolada de alimentos associados a surtos de elevada letalidade, representando um risco para a saúde pública. Em alguns países, os produtos prontos para consumo, como embutidos cozidos, entre os quais as salsichas, estão associadas à listeriose humana. Considerando a relevância do tema e a necessidade de dados, analisou-se a ocorrência de Listeria spp. e L. monocytogenes na pr...

  16. Novel Cadmium Resistance Determinant in Listeria monocytogenes.

    Science.gov (United States)

    Parsons, Cameron; Lee, Sangmi; Jayeola, Victor; Kathariou, Sophia

    2017-03-01

    Listeria monocytogenes is a foodborne pathogen that can cause severe disease (listeriosis) in susceptible individuals. It is ubiquitous in the environment and often exhibits resistance to heavy metals. One of the determinants that enables Listeria to tolerate exposure to cadmium is the cadAC efflux system, with CadA being a P-type ATPase. Three different cadA genes (designated cadA1 to cadA3 ) were previously characterized in L. monocytogenes A novel putative cadmium resistance gene ( cadA4 ) was recently identified through whole-genome sequencing, but experimental confirmation for its involvement in cadmium resistance is lacking. In this study, we characterized cadA4 in L. monocytogenes strain F8027, a cadmium-resistant strain of serotype 4b. By screening a mariner-based transposon library of this strain, we identified a mutant with reduced tolerance to cadmium and that harbored a single transposon insertion in cadA4 The tolerance to cadmium was restored by genetic complementation with the cadmium resistance cassette ( cadA4C ), and enhanced cadmium tolerance was conferred to two unrelated cadmium-sensitive strains via heterologous complementation with cadA4C Cadmium exposure induced cadA4 expression, even at noninhibitory levels. Virulence assessments in the Galleria mellonella model suggested that a functional cadA4 suppressed virulence, potentially promoting commensal colonization of the insect larvae. Biofilm assays suggested that cadA4 inactivation reduced biofilm formation. These data not only confirm cadA4 as a novel cadmium resistance determinant in L. monocytogenes but also provide evidence for roles in virulence and biofilm formation. IMPORTANCE Listeria monocytogenes is an intracellular foodborne pathogen causing the disease listeriosis, which is responsible for numerous hospitalizations and deaths every year. Among the adaptations that enable the survival of Listeria in the environment are the abilities to persist in biofilms, grow in the cold, and

  17. 78 FR 27939 - Draft Interagency Risk Assessment-Listeria monocytogenes

    Science.gov (United States)

    2013-05-13

    ... Listeria (L.) monocytogenes contamination of certain ready-to-eat (RTE) foods, for example cheese, deli... Scott, V.N., Survey of Listeria monocytogenes in ready-to-eat foods. Journal of Food Protection, 2003... monocytogenes in ready-to-eat processed meat and poultry collected in four FoodNet states in International...

  18. Occurrence of Listeria monocytogenes in smoked fish in Sokoto ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-09-03

    Sep 3, 2008 ... monocytogenes and other Listeria species are common contaminant of smoked fish, and this may pose serious public health implications. Key words: Smoked fish, Listeria monocytogenes, contamination, public health. INTRODUCTION ... L. monocytogenes belong to the recently emerging psychrotrophic ...

  19. Application of heat in postcook meat chillers reduces Listeria.

    Science.gov (United States)

    Eglezos, Sofroni; Dykes, Gary A

    2011-06-01

    Electrical air-blowing heaters were used to heat and dry out holding chillers used for postcook commercial processed meats in an attempt to control the presence of Listeria. A baseline study of the prevalence of Listeria in holding chillers in seven facilities was undertaken. Listeria was detected in four of the seven chillers, and swab samples showed Listeria prevalence ranging from 7 (7.8%) of 90 to 6 (20%) of 30, depending on the facility. Two of the facilities with established Listeria contamination (A and E) were chosen for further studies. The heating trials consisted of three individual heating interventions at each of the two facilities, with 2 weeks of postintervention sampling after each treatment. The initial Listeria prevalence in chiller A was 19 (10.6%) of 180, and treatment at 37°C for 36 h reduced prevalence to 3 (1.7%) of 180. The initial Listeria prevalence in chiller E was 7 (7.8%) of 90, and treatment at 50°C for 2 h reduced prevalence to 0 of 90. Both reductions were statistically significant at P prevalence of Listeria in chillers.

  20. 21 CFR 866.3355 - Listeria spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3355 Listeria spp... from clinical specimens. Additionally, some of these reagents consist of Listeria spp. antisera... clinical specimens. The identification aids in the diagnosis of listeriosis, a disease caused by bacteria...

  1. Incidence of Listeria monocytogenes and Other Bacteria in ...

    African Journals Online (AJOL)

    Prof. Ogunji

    Abstract. The involvement of Listeria monocytogenes in spontaneous abortion in Jos was investigated. One hundred blood and 100 placenta samples were collected from spontaneous abortion patients in Jos. The samples were inoculated first into Listeria enrichment broth. Incubation was at 37o C, followed by cold ...

  2. Incidence of Listeria monocytogenes and Other Bacteria in ...

    African Journals Online (AJOL)

    The involvement of Listeria monocytogenes in spontaneous abortion in Jos was investigated. One hundred blood and 100 placenta samples were collected from spontaneous abortion patients in Jos. The samples were inoculated first into Listeria enrichment broth. Incubation was at 37o C, followed by cold enrichment at ...

  3. Prevalence and level of Listeria monocytogenes and other Listeria sp. in ready-to-eat minimally processed and refrigerated vegetables.

    Science.gov (United States)

    Kovačević, Mira; Burazin, Jelena; Pavlović, Hrvoje; Kopjar, Mirela; Piližota, Vlasta

    2013-04-01

    Minimally processed and refrigerated vegetables can be contaminated with Listeria species bacteria including Listeria monocytogenes due to extensive handling during processing or by cross contamination from the processing environment. The objective of this study was to examine the microbiological quality of ready-to-eat minimally processed and refrigerated vegetables from supermarkets in Osijek, Croatia. 100 samples of ready-to-eat vegetables collected from different supermarkets in Osijek, Croatia, were analyzed for presence of Listeria species and Listeria monocytogenes. The collected samples were cut iceberg lettuces (24 samples), other leafy vegetables (11 samples), delicatessen salads (23 samples), cabbage salads (19 samples), salads from mixed (17 samples) and root vegetables (6 samples). Listeria species was found in 20 samples (20 %) and Listeria monocytogenes was detected in only 1 sample (1 %) of cut red cabbage (less than 100 CFU/g). According to Croatian and EU microbiological criteria these results are satisfactory. However, the presence of Listeria species and Listeria monocytogenes indicates poor hygiene quality. The study showed that these products are often improperly labeled, since 24 % of analyzed samples lacked information about shelf life, and 60 % of samples lacked information about storage conditions. With regard to these facts, cold chain abruption with extended use after expiration date is a probable scenario. Therefore, the microbiological risk for consumers of ready-to-eat minimally processed and refrigerated vegetables is not completely eliminated.

  4. Listeria Spp. and Listeria Monocytogenes Contamination in Ready-To-Eat Sandwiches Collected from Vending Machines.

    Science.gov (United States)

    Cossu, Francesca; Spanu, Carlo; Deidda, Silvia; Mura, Erica; Casti, Daniele; Pala, Carlo; Lamon, Sonia; Spanu, Vincenzo; Ibba, Michela; Marrocu, Elena; Scarano, Christian; Piana, Andrea; De Santis, Enrico Pietro Luigi

    2016-04-19

    Ready-to-eat (RTE) food is characterised by a long shelf-life at refrigerated temperature and can be consumed as such, without any treatment. The aim of the work was to evaluate the presence of Listeria spp. and Listeria monocytogenes in RTEs collected from refrigerated vending machines placed in hospital environment and accessible to the hospitalised patients. In 4 different sampling, 55 RTEs were collected from vending machines of six hospitals located in different areas of Sardinia region. All the samples were characterised by similar manufacturing process, such as the use of modified atmosphere packaging and belonged to 5 different producers. Listeria spp. was not countable using the enumeration method in all of the analysed samples. Using the detection method, Listeria spp. was recovered from 9 sandwich samples. Interestingly, 3 of these samples (5.5%) made by the manufacturer, were positive for L. monocytogenes contamination. The risk related to the L. monocytogenes presence in RTEs proportionally increases when food is introduced in susceptible environments , such as hospitals and consumed by susceptible people . Although the RTEs analysed showed values that complied with the European microbiological criteria for foodstuffs, the availability of these products in a susceptible environment should be carefully checked. Therefore, in order to limit the possible exposition to L. monocytogenes , more information on the risk related to RTE consumption should be provided to the hospitalised patients.

  5. Listeria spp. and Listeria monocytogenes contamination in ready-to-eat sandwiches collected from vending machines

    Directory of Open Access Journals (Sweden)

    Francesca Cossu

    2016-05-01

    Full Text Available Ready-to-eat (RTE food is characterised by a long shelf-life at refrigerated temperature and can be consumed as such, without any treatment. The aim of the work was to evaluate the presence of Listeria spp. and Listeria monocytogenes in RTEs collected from refrigerated vending machines placed in hospital environment and accessible to the hospitalised patients. In 4 different sampling, 55 RTEs were collected from vending machines of six hospitals located in different areas of Sardinia region. All the samples were characterised by similar manufacturing process, such as the use of modified atmosphere packaging and belonged to 5 different producers. Listeria spp. was not countable using the enumeration method in all of the analysed samples. Using the detection method, Listeria spp. was recovered from 9 sandwich samples. Interestingly, 3 of these samples (5.5% made by the manufacturer, were positive for L. monocytogenes contamination. The risk related to the L. monocytogenes presence in RTEs proportionally increases when food is introduced in susceptible environments, such as hospitals and consumed by susceptible people. Although the RTEs analysed showed values that complied with the European microbiological criteria for foodstuffs, the availability of these products in a susceptible environment should be carefully checked. Therefore, in order to limit the possible exposition to L. monocytogenes, more information on the risk related to RTE consumption should be provided to the hospitalised patients.

  6. Effect of citral and carvacrol on the susceptibility of Listeria monocytogenes and Listeria innocua to antibiotics.

    Science.gov (United States)

    Zanini, S F; Silva-Angulo, A B; Rosenthal, A; Rodrigo, D; Martínez, A

    2014-05-01

    The aim of this study was to evaluate the antibiotic susceptibility of Listeria innocua (L. innocua) and Listeria monocytogenes (L. monocytogenes) cells in the presence of citral and carvacrol at sublethal concentrations in an agar medium. The presence of terpenes in the L. monocytogenes and L. innocua culture medium provided a reduction in the minimal inhibitory concentration (MIC) of all the antibiotics tested. These effects were dependent on the concentration of terpenes present in the culture medium. The combination of citral and carvacrol potentiated antibiotic activity by reducing the MIC values of bacitracin and colistin from 32.0 and 128.0 μg ml⁻¹ to 1.0 and 2.0 μg ml⁻¹, respectively. Thus, both Listeria species became more susceptible to these drugs. In this way, the colistin and bacitracin resistance of L. monocytogenes and L. innocua was reversed in the presence of terpenes. Results obtained in this study show that the phytochemicals citral and carvacrol potentiate antibiotic activity, reducing the MIC values of cultured L. monocytogenes and L. innocua. Phytochemicals citral and carvacrol potentiate antibiotic activity of erythromycin, bacitracin and colistin by reducing the MIC values of cultured Listeria monocytogenes and Listeria innocua. This effect in reducing the MIC values of the antibiotics tested in both micro-organisms was increased when natural antimicrobials were combined. This finding indicated that the combination among terpenes and antibiotic may contribute in reducing the required dosage of antibiotics due to the possible effect of terpenes on permeation barrier of the micro-organism cell membrane. © 2014 The Society for Applied Microbiology.

  7. Assessment of Listeria sp. Interference Using a Molecular Assay To Detect Listeria monocytogenes in Food.

    Science.gov (United States)

    Zittermann, Sandra I; Stanghini, Brenda; See, Ryan Soo; Melano, Roberto G; Boleszczuk, Peter; Murphy, Allana; Maki, Anne; Mallo, Gustavo V

    2016-01-01

    Detection of Listeria monocytogenes in food is currently based on enrichment methods. When L. monocytogenes is present with other Listeria species in food, the species compete during the enrichment process. Overgrowth competition of the nonpathogenic Listeria species might result in false-negative results obtained with the current reference methods. This potential issue was noted when 50 food samples artificially spiked with L. monocytogenes were tested with a real-time PCR assay and Canada's current reference method, MFHPB-30. Eleven of the samples studied were from foods naturally contaminated with Listeria species other than those used for spiking. The real-time PCR assay detected L. monocytogenes in all 11 of these samples; however, only 6 of these samples were positive by the MFHPB-30 method. To determine whether L. monocytogenes detection can be affected by other species of the same genus due to competition, an L. monocytogenes strain and a Listeria innocua strain with a faster rate of growth in the enrichment broth were artificially coinoculated at different ratios into ground pork meat samples and cultured according to the MFHPB-30 method. L. monocytogenes was detected only by the MFHPB-30 method when L. monocytogenes/L. innocua ratios were 6.0 or higher. In contrast, using the same enrichments, the real-time PCR assay detected L. monocytogenes at ratios as low as 0.6. Taken together, these findings support the hypothesis that L. monocytogenes can be outcompeted by L. innocua during the MFHPB-30 enrichment phase. However, more reliable detection of L. monocytogenes in this situation can be achieved by a PCR-based method mainly because of its sensitivity.

  8. The Distribution of Listeria in Pasture-Raised Broiler Farm Soils Is Potentially Related to University of Vermont Medium Enrichment Bias toward Listeria innocua over Listeria monocytogenes

    Science.gov (United States)

    Locatelli, Aude; Lewis, Micah A.; Rothrock, Michael J.

    2017-01-01

    The occurrence of Listeria monocytogenes has been widely investigated in the poultry production chain from the processing plant to the final product. However, limited data are available on Listeria species, including Listeria monocytogenes, in the poultry farm environment. Therefore, fecal and soil samples from 37 pastured poultry flocks from 10 all-natural farms over 3 years were assessed to determine the prevalence and diversity of Listeria within these alternative poultry farm environments using standard cultural and molecular methods. Listeria species were isolated in 15% of poultry farm samples and included Listeria innocua (65.7%), L. monocytogenes (17.4%), and Listeria welshimeri (15.1%). Additional multiplex PCR serotyping showed group 1/2a-3a to be the most dominant L. monocytogenes serovar group. Based on these results, monoculture growth experiments were conducted on four Listeria soil isolates (three L. monocytogenes isolates representing the three recovered serovar groups and one L. innocua isolate) to determine if culture medium [tripticase soy broth (TSB) and University of Vermont modified Listeria enrichment broth (UVM)], inoculum concentration (102 or 105 CFU/ml), or incubation temperature (20, 30, and 42°C) differentially affected these Listeria species. Overall, very few significant growth differences were observed between the behavior of the three L. monocytogenes isolates (representing the three recovered serovar groups) under the growth conditions tested. Alternatively, at 30°C in UVM with the lower inoculum concentration, the L. innocua isolate had a significantly shorter lag phase than the L. monocytogenes isolates. In coculture growth studies under these same incubation conditions, the lag phase of L. innocua and L. monocytogenes was similar, but the final concentration of L. innocua was significantly higher than L. monocytogenes. However, cocultures in UVM for high inoculum concentration did not show preferential growth of L. innocua

  9. The Distribution of Listeria in Pasture-Raised Broiler Farm Soils Is Potentially Related to University of Vermont Medium Enrichment Bias toward Listeria innocua over Listeria monocytogenes.

    Science.gov (United States)

    Locatelli, Aude; Lewis, Micah A; Rothrock, Michael J

    2017-01-01

    The occurrence of Listeria monocytogenes has been widely investigated in the poultry production chain from the processing plant to the final product. However, limited data are available on Listeria species, including Listeria monocytogenes , in the poultry farm environment. Therefore, fecal and soil samples from 37 pastured poultry flocks from 10 all-natural farms over 3 years were assessed to determine the prevalence and diversity of Listeria within these alternative poultry farm environments using standard cultural and molecular methods. Listeria species were isolated in 15% of poultry farm samples and included Listeria innocua (65.7%), L. monocytogenes (17.4%), and Listeria welshimeri (15.1%). Additional multiplex PCR serotyping showed group 1/2a-3a to be the most dominant L. monocytogenes serovar group. Based on these results, monoculture growth experiments were conducted on four Listeria soil isolates (three L. monocytogenes isolates representing the three recovered serovar groups and one L. innocua isolate) to determine if culture medium [tripticase soy broth (TSB) and University of Vermont modified Listeria enrichment broth (UVM)], inoculum concentration (10 2 or 10 5  CFU/ml), or incubation temperature (20, 30, and 42°C) differentially affected these Listeria species. Overall, very few significant growth differences were observed between the behavior of the three L. monocytogenes isolates (representing the three recovered serovar groups) under the growth conditions tested. Alternatively, at 30°C in UVM with the lower inoculum concentration, the L. innocua isolate had a significantly shorter lag phase than the L. monocytogenes isolates. In coculture growth studies under these same incubation conditions, the lag phase of L. innocua and L. monocytogenes was similar, but the final concentration of L. innocua was significantly higher than L. monocytogenes . However, cocultures in UVM for high inoculum concentration did not show preferential growth of L

  10. Prevalence and location of Listeria monocytogenes in farmed rainbow trout.

    Science.gov (United States)

    Miettinen, Hanna; Wirtanen, Gun

    2005-10-15

    A total of 510 rainbow trout originating from fish farms in lakes and sea areas around Finland were studied for the presence of Listeria monocytogenes. Samples were studied as pools from five fish. Gill, viscera, and skin from the pooled samples were analysed separately. The individual samples were analysed later if the pooled sample was found to be Listeria positive. The prevalence of Listeria spp. and L. monocytogenes in pooled unprocessed fresh rainbow trout was on average 35.0% and 14.6%, respectively. On the other hand, the prevalence of Listeria spp. and L. monocytogenes in individual thawed fish was found to be 14.3% and 8.8%, respectively. These numbers tend to overestimate and underestimate the real situation because not all fish in pooled samples were necessarily contaminated and in some of the Listeria positive pooled samples all individual samples turned out to be Listeria free. The prevalence of L. monocytogenes varied greatly between different fish farms from zero to 100% in pooled samples and from zero to 75% according to individually studied fish samples. Some indications of the influence of weather conditions and seasonal variations that strongly affected the Listeria contamination of fish were also noticed. The location of Listeria spp. and L. monocytogenes in different parts of the fish differed with statistical significance in rainbow trout. Up to 95.6% of the L. monocytogenes and 84.5% of Listeria spp. positive samples were gill samples. Only 4.4% (2/45) of the L. monocytogenes positive samples were obtained from skin or viscera. Closer study at one fish farm revealed that there was only one L. monocytogenes ribotype present in the contaminated fish, although water and surfaces were heavily contaminated with six other L. monocytogenes ribotypes.

  11. Epidemiologia molecular de Listeria monocytogenes isoladas de diferentes fontes no Brasil

    Directory of Open Access Journals (Sweden)

    Andrea Micke Moreno

    2013-04-01

    Full Text Available Listeria monocytogenes é um importante patógeno de origem alimentar que afeta principalmente grávidas, neonatos, idosos e indivíduos imunocomprometidos, e pode causar abortamento, septicemia e meningite. Dos 13 grupos capsulares descritos, os sorotipos 4b, 1/2b e 1/2a são os mais relacionados à infecção humana. Por esta razão, a sorotipagem possui valor limitado como ferramenta epidemiológica e, dessa forma, métodos mais discriminatórios são necessários para melhorar o conhecimento sobre a contaminação e a infecção por L. monocytogenes. O objetivo deste estudo foi caracterizar a diversidade genética de isolados de L. monocytogenes da indústria de processamento de carne suína no Estado de São Paulo, Brasil, e compará-los a isolados de casos de infecção humana através do ERIC-PCR e AFLP com uma única enzima. Os sorotipos 1/2c e 4b foram frequentes em carne suína e ambientes de abatedouros e mercados, enquanto os sorotipos 4b e 1/2a foram observados nos isolados de humanos. ERIC-PCR e AFLP resultaram em 34 e 31 perfis distintos, respectivamente, com uma tendência a separar de acordo com o sorogrupo e a origem do isolado. Os perfis genéticos de ambiente dos abatedouros e mercados sugerem a possibilidade de diferentes origens de contaminação por Listeria nos ambientes estudados, porém, em alguns casos, é possível que ocorra a persistência de cepas clonais causando contaminação contínua.

  12. [Prevalence of emerging foodborne pathogens and illness: Campylobacter and Listeria].

    Science.gov (United States)

    Ferriero, Anna Maria; Damiani, Gianfranco; Neve, Caterina Bianca; Bianchi, Aurora; Ronconi, Alessandra; Laurenti, Patrizia

    2011-01-01

    This study evaluated the proportion of food samples, examined by the Italian Istituti Zooprofilattici Sperimentali (Experimental Zooprophylactic Institutes) in the years 2000-2005, positive for Campylobacter and Listeria. A correlation was found between food samples found positive for Listeria in the years 2002-2005 and the number of hospitalisations for Listeria illness in the same years (as reported in hospital discharge abstract forms). This confirms that attention should be given in the evaluation of phenomena known to be under reported and for which data are collected and analysed by different methods.

  13. Recombinant phage probes for Listeria monocytogenes

    Energy Technology Data Exchange (ETDEWEB)

    Carnazza, S; Gioffre, G; Felici, F; Guglielmino, S [Department of Microbiological, Genetic and Molecular Sciences, University of Messina, Messina (Italy)

    2007-10-03

    Monitoring of food and environmental samples for biological threats, such as Listeria monocytogenes, requires probes that specifically bind biological agents and ensure their immediate and efficient detection. There is a need for robust and inexpensive affinity probes as an alternative to antibodies. These probes may be recruited from random peptide libraries displayed on filamentous phage. In this study, we selected from two phage peptide libraries phage clones displaying peptides capable of specific and strong binding to the L. monocytogenes cell surface. The ability of isolated phage clones to interact specifically with L. monocytogenes was demonstrated using enzyme-linked immunosorbent assay (ELISA) and confirmed by co-precipitation assay. We also assessed the sensitivity of phage-bacteria binding by PCR on phage-captured Listeria cells, which could be detected at a concentration of 10{sup 4} cells ml{sup -1}. In addition, as proof-of-concept, we tested the possibility of immobilizing the affinity-selected phages to a putative biosensor surface. The quality of phage deposition was monitored by ELISA and fluorescent microscopy. Phage-bacterial binding was confirmed by high power optical phase contrast microscopy. Overall, the results of this work validate the concept of affinity-selected recombinant filamentous phages as probes for detecting and monitoring bacterial agents under any conditions that warrant their recognition, including in food products.

  14. Recombinant phage probes for Listeria monocytogenes

    Science.gov (United States)

    Carnazza, S.; Gioffrè, G.; Felici, F.; Guglielmino, S.

    2007-10-01

    Monitoring of food and environmental samples for biological threats, such as Listeria monocytogenes, requires probes that specifically bind biological agents and ensure their immediate and efficient detection. There is a need for robust and inexpensive affinity probes as an alternative to antibodies. These probes may be recruited from random peptide libraries displayed on filamentous phage. In this study, we selected from two phage peptide libraries phage clones displaying peptides capable of specific and strong binding to the L. monocytogenes cell surface. The ability of isolated phage clones to interact specifically with L. monocytogenes was demonstrated using enzyme-linked immunosorbent assay (ELISA) and confirmed by co-precipitation assay. We also assessed the sensitivity of phage-bacteria binding by PCR on phage-captured Listeria cells, which could be detected at a concentration of 104 cells ml-1. In addition, as proof-of-concept, we tested the possibility of immobilizing the affinity-selected phages to a putative biosensor surface. The quality of phage deposition was monitored by ELISA and fluorescent microscopy. Phage-bacterial binding was confirmed by high power optical phase contrast microscopy. Overall, the results of this work validate the concept of affinity-selected recombinant filamentous phages as probes for detecting and monitoring bacterial agents under any conditions that warrant their recognition, including in food products.

  15. Transfer of antibiotic resistance from Enterococcus faecium of fermented meat origin to Listeria monocytogenes and Listeria innocua.

    Science.gov (United States)

    Jahan, M; Holley, R A

    2016-04-01

    Listeria monocytogenes is an important foodborne pathogen that can cause infection in children, pregnant women, the immunocompromised and the elderly. Antibiotic resistance in this species would represent a significant public health problem since the organism has a high fatality/case ratio and resistance may contribute to failure of therapeutic treatment. This study was designed to explore whether the in vitro transferability of antibiotic resistance from enterococci to Listeria spp. could occur. It was found that 2/8 Listeria strains were able to acquire tetracycline resistance from Enterococcus faecium. Listeria monocytogenes GLM-2 acquired the resistance determinant tet(M) and additional streptomycin resistance through in vitro mating with Ent. faecium S27 isolated from commercial fermented dry sausage. Similarly, Listeria innocua became more resistant to tetracycline, but the genetic basis for this change was not confirmed. It has been suggested that enterococci may transfer antibiotic resistance genes via transposons to Listeria spp., and this may explain, in part, the origin of their antibiotic resistance. Thus, the presence of enterococci in food should not be ignored since they may actively contribute to enhanced antibiotic resistance of L. monocytogenes and other pathogens. Acquisition of antibiotic resistance by pathogenic bacteria in the absence of antibiotic pressure represents an unquantified threat to human health. In the present work resistance to tetracycline and streptomycin were transferred by nonplasmid-based conjugation from Enterococcus faecium isolated from fermented sausage to Listeria monocytogenes and Listeria innocua. Thus, natural transfer of antibiotic resistance to Listeria strains may occur in the future which reinforces the concern about the safety of enterococcal strains present in foods. © 2016 The Society for Applied Microbiology.

  16. Listeria prevalence and Listeria monocytogenes serovar diversity at cull cow and bull processing plants in the United States.

    Science.gov (United States)

    Guerini, Michael N; Brichta-Harhay, Dayna M; Shackelford, T Steven D; Arthur, Terrance M; Bosilevac, Joseph M; Kalchayanand, Norasak; Wheeler, Tommy L; Koohmaraie, Mohammad

    2007-11-01

    Listeria monocytogenes, the causative agent of epidemic and sporadic listeriosis, is routinely isolated from many sources, including cattle, yet information on the prevalence of Listeria in beef processing plants in the United States is minimal. From July 2005 through April 2006, four commercial cow and bull processing plants were sampled in the United States to determine the prevalence of Listeria and the serovar diversity of L. monocytogenes. Samples were collected during the summer, fall, winter, and spring. Listeria prevalence on hides was consistently higher during cooler weather (28 to 92% of samples) than during warmer weather (6 and 77% of samples). The Listeria prevalence data collected from preevisceration carcass ranged from undetectable in some warm season samples to as high as 71% during cooler weather. Listeria on postintervention carcasses in the chill cooler was normally undetectable, with the exception of summer and spring samples from one plant where > 19% of the carcasses were positive for Listeria. On hides, L. monocytogenes serovar 1/2a was the predominant serovar observed, with serovars 1/2b and 4b present 2.5 times less often and serovar 1/2c not detected on any hides sampled. L. monocytogenes serovars 1/2a, 1/2c, and 4b were found on postintervention carcasses. This prevalence study demonstrates that Listeria species are more prevalent on hides during the winter and spring and that interventions being used in cow and bull processing plants appear to be effective in reducing or eliminating Listeria contamination on carcasses.

  17. Evaluation of a monoclonal antibody able to detect live Listeria monocytogenes and Listeria innocua

    DEFF Research Database (Denmark)

    Sølve, Marianne; Boel, Jeppe; Nørrung, Birgit

    2000-01-01

    A monoclonal Listeria antibody, designated B4, was evaluated. The ability of the antibody to bind to viable bacteria belonging to Listeria spp, compared to bacteria of the same species killed by beat treatment, acid or base treatment, sanitizers, and irradiation was examined. The antibody was found...... to react with viable L. monocytogenes and L. innocua, but not with heat-killed (72 degrees C, 5 min) strains of these organisms. When L. monocytogenes and L. innocua were killed by methods other than heat treatment, it was ambiguous whether the antibody detected the organism or not. It was concluded...... that the B4 antibody has potential to be used in an immune capture step to capture live L, monocytogenes and L. innocua from foods prior to identification of L. monocytogenes by polymerase chain reaction (PCR)....

  18. Incidence of Listeria monocytogenes and Listeria spp. in a small-scale mushroom production facility.

    Science.gov (United States)

    Viswanath, Prema; Murugesan, Latha; Knabel, Stephen J; Verghese, Bindhu; Chikthimmah, Naveen; Laborde, Luke F

    2013-04-01

    Listeria monocytogenes is a foodborne pathogen of significant concern to the agricultural and food processing industry because of its ability to grow and persist in cool and moist environments and its association with listeriosis, a disease with a very high mortality rate. Although there have been no listeriosis outbreaks attributed to fresh mushrooms in the United States, retail surveys and recalls are evidence that L. monocytogenes contamination of mushrooms (Agaricus bisporus) can occur. The objective of this study was to determine the prevalence of Listeria spp., including L. monocytogenes, in a small-scale mushroom production facility on the campus of the Pennsylvania State University in the United States. Of 184 samples taken from five production zones within the facility, 29 (15.8%) samples were positive for Listeria spp. Among the Listeria spp. isolates, L. innocua was most prevalent (10.3%) followed by L. welshimeri (3.3%), L. monocytogenes (1.6%), and L. grayi (0.5%). L. monocytogenes was recovered only from the phase I raw material composting area. Isolates of L. monocytogenes were confirmed and serotyped by multiplex PCR. The epidemiological relatedness of the three L. monocytogenes isolates to those serotypes or lineages frequently encountered in listeriosis infections was determined by multi-virulence-locus sequence typing using six virulence genes, namely, prfA, inlB, inlC, dal, clpP, and lisR. The phylogenetic positions of the three isolates in the dendrogram prepared with data from other isolates of L. monocytogenes showed that all isolates were grouped with serotype 4a, lineage IIIA. To date, this serotype has rarely been reported in foodborne disease outbreaks.

  19. Incidence and pathogenicity profile of Listeria sp. isolated from food ...

    African Journals Online (AJOL)

    USER

    2010-07-26

    Jul 26, 2010 ... in the brain, adrenal glands, spleen, kidney, lungs and the gastrointestinal ..... Cryptogenic liver abscess due to Listeria monocytogenes. .... of foods in sporadic listeriosis I. Case – control study of dietry risk factors. J. Am. Med.

  20. Stalling autophagy: a new function for Listeria phospholipases

    Directory of Open Access Journals (Sweden)

    Ivan Tattoli

    2014-01-01

    Full Text Available Listeria monocytogenes is a Gram-positive bacterial pathogen that induces its own uptake in non-phagocytic cells. Following invasion, Listeria escapes from the entry vacuole through the secretion of a pore-forming toxin, listeriolysin O (LLO that acts to damage and disrupt the vacuole membrane. Listeria then replicates in the cytosol and is able to spread from cell-to-cell using actin-based motility. In addition to LLO, Listeria produces two phospholipase toxins, a phosphatidylinositol-specific phospholipase C (PI-PLC, encoded by plcB and a broad-range phospholipase C (PC-PLC, encoded by plcA, which contribute to bacterial virulence. It has long been recognized that secretion of PI- and PC-PLC enables the disruption of the double membrane vacuole during cell-to-cell spread, and those phospholipases have also been shown to augment LLO-dependent escape from the entry endosome. However, a specific role for Listeria phospholipases during the cytosolic stage of infection has not been previously reported. In a recent study, we demonstrated that Listeria PI-PLC and PC-PLC contribute to the bacterial escape from autophagy through a mechanism that involves direct inhibition of the autophagic flux in the infected cells [Tattoli et al. EMBO J (2013, 32, 3066-3078].

  1. OrfX, a Nucleomodulin Required for Listeria monocytogenes Virulence

    Directory of Open Access Journals (Sweden)

    Andrzej Prokop

    2017-10-01

    Full Text Available Listeria monocytogenes is a bacterial pathogen causing severe foodborne infections in humans and animals. Listeria can enter into host cells and survive and multiply therein, due to an arsenal of virulence determinants encoded in different loci on the chromosome. Several key Listeria virulence genes are clustered in Listeria pathogenicity island 1. This important locus also contains orfX (lmo0206, a gene of unknown function. Here, we found that OrfX is a small, secreted protein whose expression is positively regulated by PrfA, the major transcriptional activator of Listeria virulence genes. We provide evidence that OrfX is a virulence factor that dampens the oxidative response of infected macrophages, which contributes to intracellular survival of bacteria. OrfX is targeted to the nucleus and interacts with the regulatory protein RybP. We show that in macrophages, the expression of OrfX decreases the level of RybP, which controls cellular infection. Collectively, these data reveal that Listeria targets RybP and evades macrophage oxidative stress for efficient infection. Altogether, OrfX is after LntA, the second virulence factor acting directly in the nucleus.

  2. Stress Distribution, Friction and Listeria Propulsion

    Science.gov (United States)

    Prost, Jacques

    2003-03-01

    I will review our work on the physics of listeria propulsion based on an unavoidable elastic analysis of the stress distribution in the actin gel and dynamical boundary conditions (both normal and tangential). I will show in particular that it provides a natural explanation for the symmetry breaking transition occurring with beads (work with K. Sekimoto and F. Julicher), of the saltatory behavior of beads reported by A Bernheim et al (Nature 2002) and of the shape of soft beads (with O. Campas and J.F Joanny). This last analysis proves that, as announced in an earlier paper (F; Gerbal et al Biophys Journal 2000) the rear part of the gel contributes negatively to the motion.

  3. Sensitivity of Listeria monocytogenes to irradiation

    International Nuclear Information System (INIS)

    Tarjan, Veronika

    1990-01-01

    Irradiation of Listeria monocytogenes (L.m.) was carried out in culture media and pork meat paste at room temperature with 60 Co radiation source of 6.6 kGy h -1 dose rate. The employed doses were 0, 0.5, 1, 2, 3, 4 and 6 kGy. One strain out of 3 survived as high as 4 kGy irradiation. Radiation with 2 kGy resulted 7 log cycles reduction of cell count. After lower irradiation doses the L.m. count decreased in proportion to increasing doses. It has been concluded that L.m. compared with Gram-negative pathogens, are less sensitive to irradiation. (author) 6 refs.; 4 figs

  4. "Quantificação de Listeria monocytogenes em salames fatiados embalados a vácuo"

    OpenAIRE

    Ichiro Sakate, Ricardo; Casale Aragon, Lina; Raghiante, Fernanda; Landgra, Mariza; Bernadette D. G. M, Franco; Destro, Maria Teresa

    2003-01-01

    RESUMO. Pouco se sabe, no Brasil e na América do Sul, sobre a ocorrência de Listeria monocytogenes em embutidos cárneos fermentados, fatiados, embalados a vácuo. Por suas características de produção e armazenamento, estes produtos são potenciais veiculadores deste patógeno ao ser humano, principalmente imunodeprimidos, idosos e grávidas, levando a disfunções gastrintestinais e neurológicas. Neste trabalho, foram analisadas 45 amostras de diferentes tipos e marcas de salames fatiados embalados...

  5. Meningitis neonatal e infección puerperal por Streptococcus pneumoniae: Presentación de un caso

    Directory of Open Access Journals (Sweden)

    Cecilia Ortiz Rodríguez

    2003-06-01

    Full Text Available Las infecciones neonatales causadas por Streptococcus pneumoniae constituyen un fenómeno raro, poco reportado en la literatura médica; en el presente trabajo se describe el caso de una meningoencefalitis purulenta de aparición precoz, en un neonato nacido por parto eutócico, a termino y de buen peso. Se aisló el microorganismo en la sangre y en el líquido cefalorraquídeo del recién nacido, así como en los loquios de la madre. Las 3 antibiotipias fueron idénticas. La evolución del niño fue desfavorable, el cual falleció a las 81 horas de vida, en un cuadro de fallo multiorgánico. La necropsia corroboró el diagnóstico. La madre desarrolló una endometritis puerperal a los 4 días, con buena evolución.Neonatal infections caused by Streptococcus pneumoniae are a rare phenomenon that is barely reported in the medical literature. The present paper describes a case of early purulent meningoencephalitis occurred in an adequate birthweight neonate born to term eutocic delivery. The microorganism was isolated in the newborn's blood and cerebrospinal fluid as well as in his mother's lochia. The three antibiotypes were identical. The newborn did not recover and died after 81 hours due to a multiple organ failure. Necropsy confirmed the diagnosis. The mother developed puerperal endometritis after 4 days but did recover.

  6. Novel PCR Assays Complement Laser Biosensor-Based Method and Facilitate Listeria Species Detection from Food

    Directory of Open Access Journals (Sweden)

    Kwang-Pyo Kim

    2015-09-01

    Full Text Available The goal of this study was to develop the Listeria species-specific PCR assays based on a house-keeping gene (lmo1634 encoding alcohol acetaldehyde dehydrogenase (Aad, previously designated as Listeria adhesion protein (LAP, and compare results with a label-free light scattering sensor, BARDOT (bacterial rapid detection using optical scattering technology. PCR primer sets targeting the lap genes from the species of Listeria sensu stricto were designed and tested with 47 Listeria and 8 non-Listeria strains. The resulting PCR primer sets detected either all species of Listeria sensu stricto or individual L. innocua, L. ivanovii and L. seeligeri, L. welshimeri, and L. marthii without producing any amplified products from other bacteria tested. The PCR assays with Listeria sensu stricto-specific primers also successfully detected all species of Listeria sensu stricto and/or Listeria innocua from mixed culture-inoculated food samples, and each bacterium in food was verified by using the light scattering sensor that generated unique scatter signature for each species of Listeria tested. The PCR assays based on the house-keeping gene aad (lap can be used for detection of either all species of Listeria sensu stricto or certain individual Listeria species in a mixture from food with a detection limit of about 104 CFU/mL.

  7. Listeria spp. occurrence in equipments and processing plants of meat/ Listeria spp. ocorrência em equipamentos e ambientes de processamento de carne bovina

    Directory of Open Access Journals (Sweden)

    Luís Augusto Nero

    2004-05-01

    Full Text Available Exopolysaccharides, biopolymers or hydrosolubles gums, are produced by a great variety of microorganisms and possess physical, structural and chemical properties quite homogeneous, in relation to derived from algae and plants. The production is relatively independent on climatic conditions, faster obtaining of the finished product and need small space. Biopolymers have been studied thoroughly in the last years. Due to wide diversity in structure and physical properties, the microbial polysaccharides possess a lot of applications in food, pharmaceutical, oil, cosmetics, textile, inks and agricultural products among others industries. Some of those applications, include uses as emulsifying, stabilizing, binding, jellifying, clotting, lubricants, film coated, thickening and suspender agents. The parameters that have most influenced the process of exopolysaccharides biosyntheses have been the microorganism, the culture medium composition, pH and temperature of incubation. The exopolysaccharide production can be developed by species of Gram-negative and Gram-positive bacteria, some microalgae and many moulds. This work discusses the influence of these parameters during the production process and exopolysaccharides biosyntheses by bacteria.O objetivo desta pesquisa foi estabelecer a ocorrência de Listeria monocytogenes em diversos pontos de plantas de processamento de carne bovina em 01 abatedouro e 05 casas de carnes localizados na região norte do Paraná. Para a detecção de Listeria spp. em 124 amostras de equipamentos/utensílios e instalações, utilizou-se a metodologia preconizada pelo United States Departament of Agriculture (USDA, com identificação das espécies por testes bioquímicos e posterior confirmação pelo API Listeria (bioMérieux. Os resultados obtidos indicaram freqüências de 6,25% de L. monocytogenes; 68,75% de L. innocua; 18,75% de L. welshimeri; 4,17% de L. seeligeri e 2,08% de L. grayi. As amostras positivas para L

  8. Prevalence of Listeria spp. and Molecular Characterization of Listeria monocytogenes Isolates from Broilers at the Abattoir.

    Science.gov (United States)

    Bouayad, Leila; Hamdi, Taha M; Naim, Malek; Leclercq, Alexandre; Lecuit, Marc

    2015-07-01

    Products from three broiler abattoirs were sampled for Listeria species to evaluate the changes in the prevalence and contamination rates at two stages of processing. Sampling was performed at the evisceration stage and at the end of processing after packaging and refrigerating at 4°C for 24 h. A total of 212 samples were collected; 52 were from abattoir A, and 80 samples each were collected from abattoirs B and C. Among all samples, 99 (46.7%) tested positive for Listeria, including L. monocytogenes 19 (8.9%), L. innocua 69 (32.5%), L. grayi 10 (4.7%), and L. welshimeri 1 (0.5%). The L. monocytogenes contamination rate varied from 5% to 11.5% in the 3 abattoirs. L. innocua was the most common species identified and was found in 8.8% of the samples from abattoir A and 33.7% of the samples from both abattoirs B and C. Twenty-six of the L. monocytogenes isolates obtained from positive samples were subjected to serotyping by multiplex polymerase chain reaction and characterization by the pulsed-field gel electrophoresis (PFGE) method using two cutting enzymes, ApaI and AscI. Three molecular serogroups were identified: IIa, IIb, and IVb. Serogroup IIa was common to all abattoirs, and serogroups IIb and IVb were found only in abattoir C. The 10 different obtained PFGE profiles were grouped into 7 clusters; some of these clusters were common to the 3 abattoirs, and others were specific to the abattoirs in which they were identified. This study revealed a high prevalence of Listeria spp., particularly L. monocytogenes, in raw broilers. This high incidence presents a risk to consumers due to the potential occurrence of cross-contamination with other foods in domestic refrigerators and the ability of these microorganisms to survive in undercooked products.

  9. Recombinant probiotic expressing Listeria adhesion protein attenuates Listeria monocytogenes virulence in vitro.

    Directory of Open Access Journals (Sweden)

    Ok Kyung Koo

    Full Text Available BACKGROUND: Listeria monocytogenes, an intracellular foodborne pathogen, infects immunocompromised hosts. The primary route of transmission is through contaminated food. In the gastrointestinal tract, it traverses the epithelial barrier through intracellular or paracellular routes. Strategies to prevent L. monocytogenes entry can potentially minimize infection in high-risk populations. Listeria adhesion protein (LAP aids L. monocytogenes in crossing epithelial barriers via the paracellular route. The use of recombinant probiotic bacteria expressing LAP would aid targeted clearance of Listeria from the gut and protect high-risk populations from infection. METHODOLOGY/PRINCIPAL FINDINGS: The objective was to investigate the ability of probiotic bacteria or LAP-expressing recombinant probiotic Lactobacillus paracasei (Lbp(LAP to prevent L. monocytogenes adhesion, invasion, and transwell-based transepithelial translocation in a Caco-2 cell culture model. Several wild type probiotic bacteria showed strong adhesion to Caco-2 cells but none effectively prevented L. monocytogenes infection. Pre-exposure to Lbp(LAP for 1, 4, 15, or 24 h significantly (P<0.05 reduced adhesion, invasion, and transepithelial translocation of L. monocytogenes in Caco-2 cells, whereas pre-exposure to parental Lb. paracasei had no significant effect. Similarly, Lbp(LAP pre-exposure reduced L. monocytogenes translocation by as much as 46% after 24 h. Lbp(LAP also prevented L. monocytogenes-mediated cell damage and compromise of tight junction integrity. Furthermore, Lbp(LAP cells reduced L. monocytogenes-mediated cell cytotoxicity by 99.8% after 1 h and 79% after 24 h. CONCLUSIONS/SIGNIFICANCE: Wild type probiotic bacteria were unable to prevent L. monocytogenes infection in vitro. In contrast, Lbp(LAP blocked adhesion, invasion, and translocation of L. monocytogenes by interacting with host cell receptor Hsp60, thereby protecting cells from infection. These data show promise

  10. OCORRÊNCIA DE Listeria monocytogenes EM ABATEDOURO-FRIGORIFICO DE SUÍNOS DA REGIÃO DOS CAMPOS GERAIS – PR

    OpenAIRE

    Monteiro, Francielli Casanova; UTFPR; Samulak, Renata Louise; Montanhini, Maike Tais Maziero; Bittencourt, Juliana Vitória Messias

    2014-01-01

    Listeria monocytogenes é um micro-organismo que está vastamente propagado no ambiente. A contaminação por este patógeno pode ser considerada um problema de saúde publica pois se consumido por gestantes e idosos pode levar o individuo a óbito, e o mesmo tem a habilidade de sobreviver mesmo com a aplicação dos sanitizantes recomendados pela legislação vigente. Como alternativa à microbiologia convencional utilizada nas industrias de alimentos, os métodos envolvendo biologia molecular vem se tor...

  11. Listeria monocytogenes and Listeria spp. contamination patterns in retail delicatessen establishments in three U.S. states.

    Science.gov (United States)

    Simmons, Courtenay; Stasiewicz, Matthew J; Wright, Emily; Warchocki, Steven; Roof, Sherry; Kause, Janell R; Bauer, Nathan; Ibrahim, Salam; Wiedmann, Martin; Oliver, Haley F

    2014-11-01

    Postprocessing contamination in processing plants has historically been a significant source of Listeria monocytogenes in ready-to-eat delicatessen meats, and therefore a major cause of human listeriosis cases and outbreaks. Recent risk assessments suggest that a majority of human listeriosis cases linked to consumption of contaminated deli meats may be due to L. monocytogenes contamination that occurs at the retail level. To better understand the ecology and transmission of Listeria spp. in retail delicatessens, food and nonfood contact surfaces were tested for L. monocytogenes and other Listeria spp. in a longitudinal study conducted in 30 retail delis in three U.S. states. In phase I of the study, seven sponge samples were collected monthly for 3 months in 15 delis (5 delis per state) prior to start of daily operation; in phase II, 28 food contact and nonfood contact sites were sampled in each of 30 delis during daily operation for 6 months. Among the 314 samples collected during phase I, 6.8% were positive for L. monocytogenes. Among 4,503 samples collected during phase II, 9.5% were positive for L. monocytogenes; 9 of 30 delis showed low L. monocytogenes prevalence (Listeria spp. isolates, including 184 Listeria innocua, 48 Listeria seeligeri, and 13 Listeria welshimeri were characterized. Pulsed-field gel electrophoresis (PFGE) was used to characterize 446 L. monocytogenes isolates. PFGE showed that for 12 of 30 delis, one or more PFGE types were isolated on at least three separate occasions, providing evidence for persistence of a given L. monocytogenes subtype in the delis. For some delis, PFGE patterns for isolates from nonfood contact surfaces were distinct from patterns for occasional food contact surface isolates, suggesting limited cross-contamination between these sites in some delis. This study provides longitudinal data on L. monocytogenes contamination patterns in retail delis, which should facilitate further development of control strategies in

  12. Inactivation of Salmonella and Listeria in ground chicken breast meat during thermal processing.

    Science.gov (United States)

    Murphy, R Y; Marks, B P; Johnson, E R; Johnson, M G

    1999-09-01

    Thermal inactivation of six Salmonella spp. and Listeria innocua was evaluated in ground chicken breast and liquid medium. Survival of Salmonella and Listeria was affected by the medium composition. Under the same thermal process condition, significantly more Salmonella and Listeria survived in chicken breast meat than in 0.1% peptone-agar solution. The thermal lethality of six tested Salmonella spp. was additive in chicken meat. Survival of Listeria in chicken meat during thermal processing was not affected by the presence of the six Salmonella spp. Sample size and shape affected the inactivation of Salmonella and Listeria in chicken meat during thermal processing.

  13. The search of Listeria and Salmonella in different food matrices

    International Nuclear Information System (INIS)

    Ben Saad, Emna

    2010-01-01

    The foods safety and security does not cease to be a priority. Although foods contaminants generate changes in the sensory characteristics, they may cause diseases and pose a risk to human health. This study includes a targeted search of two food borne pathogens Listeria and Salmonella responsible respectively of two serious infections listeriosis and salmonellosis. 100 Food samples taken from the market for public consumption are analyzed in the CNSTN laboratory of microbiology and molecular biology. Once isolated (eight strains of Listeria and one of Salmonella), the strains were identified by Api (Listeria and 20E) and PCR. The results obtained show the ability of our products to be contaminated which arise the importance of strengthening measures of prevention and health control.

  14. Early trigeminal nerve involvement in Listeria monocytogenes rhombencephalitis

    DEFF Research Database (Denmark)

    Karlsson, William K; Harboe, Zitta Barrella; Roed, Casper

    2017-01-01

    dysfunction on that side. In addition, we identified another 120 cases of Listeria rhombencephalitis following a systematic review. Cranial nerves VII, V, IX, and X, respectively, medulla oblongata, cerebellum and pons, were the most frequently involved brain structures. The present clinical and radiological...... findings corroborate earlier data from animal experiments, indicating that L. monocytogenes may be capable of retrograde intra-axonal migration along the cranial nerves. We suggest that in a subset of patients with rhombencephalitis L. monocytogenes enters the cerebellopontine angle through the trigeminal......Listeria monocytogenes is associated with rhombencephalitis. However, the exact mechanisms of brainstem invasion remains poorly understood. Here, we demonstrate clinical and radiological data suggesting that Listeria may invade the brainstem via the trigeminal nerve. Three females (41, 64 and 70...

  15. COMPARISON OF TWO METHODS FOR THE DETECTION OF LISTERIA MONOCYTOGENES

    Directory of Open Access Journals (Sweden)

    G. Tantillo

    2013-02-01

    Full Text Available The aim of this study was to compare the performance of the conventional methods for detection of Listeria monocytogenes in food using media Oxford and ALOA (Agar Listeria acc. to Ottaviani & Agosti in according to the ISO 11290-1 to a new chromogenic medium “CHROMagar Listeria” standardized in 2005 AFNOR ( CHR – 21/1-12/01. A total of 40 pre-packed ready-to-eat food samples were examined. Using two methods six samples were found positive for Listeria monocytogenes but the medium “CHROMagar Listeria” was more selective in comparison with the others. In conclusion this study has demonstrated that isolation medium able to target specifically the detection of L. monocytogenes such as “CHROMagar Listeria” is highly recommendable because of that detection time is significantly reduced and the analysis cost is less expensive.

  16. [Analysis of antibiotic susceptibility of foodborne Listeria monocytogenes in China].

    Science.gov (United States)

    Yang, Yang; Fu, Ping; Guo, Yunchang; Liu, Xiurmei

    2008-03-01

    To study the antibiotic susceptibility of foodborne Listeria monocytogenes in China. The susceptibilities of 476 strains of foodborne Listeria monocytogenes to antibiotics were determined in Broth Microdilution Susceptibility Testing in Clinical and Laboratory Standards Institute. The antibiotics of gentamicin, ampicillin, penicillin, tetracycline, doxycycline, imipenem, erythromycin, ciprofloxacin, levofloxacin, cephalothin, rifampin, vancomycin, chloramphenicol, Trimethoprim-sulfamethoxazole, ampicillin-sulbactam were used. The rates of antibiotic resistance in 467 is olates were 4.5%. Tetracycline resistance was most prevalent, accouting for 4.07% . The foods that the rates of antibiotic resistance were highest were vegetable (10%). Among 14 provinces, Jilin, Hubei and Hebei were the third top, the rate of which were 19.6% and 9.1% and 8%, respectively. It was suggested that antibiotic resistance exists in foodborne Listeria monocytogenes to a certain extent in China. It should pay more attention to the use of drugs in prevention and clinic treatment to reduce the antibiotic resistant strains.

  17. [A Listeria breast abscess in a man].

    Science.gov (United States)

    Marsaudon, E; Berthy, J; Mamoune, S; Deniel, A; Ksiyer, S; Tiuca, D

    2018-03-01

    Listeriosis is a food-borne illness leading to bacteriemia or central nervous system infection especially in pregnant women or high-risk patients. It is rarely a localized infection. Breast contamination has rarely been reported in lactating women. We report a breast abscess in man. A 80 year old man, hypertensive and arrhythmic, was explored for weakness and dehydration. Type 2 diabetes and chronic lymphocytic leukemia were diagnosed. Clinical examination disclosed a breast abcess related to L monocytogenes infection. Histopathological study also revealed a breast subcutaneous infiltration by chronic lymphocytic leukemia. Listeriosis sometimes uncover an unknown immunosuppression, especially in the elderly. Breast is a non-sterile tissue containing a stable microbiome partly from digestive origin. It can thereby be contaminated by Listeria. The specific cutaneous infiltrate of chronic lymphocytic leukemia can create the conditions for a local infection. Copyright © 2017 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier SAS. All rights reserved.

  18. Listeria monocytogenes: Overview and Targeting Advances

    Directory of Open Access Journals (Sweden)

    Mostafa F.N. Abushahba

    2016-04-01

    Full Text Available Listeria monocytogenes is a serious foodborne zoonotic pathogen capable of causing gastroenteritis and severe systemic infections such as septicemia, meningitis or abortion in the infected individuals what is called listeriosis. The bacterium is reported as the third leading cause of death among the foodborne pathogens preceded by nontyphoidal Salmonella spp. and Toxoplasma gondii. The power to tolerate a wide range of temperatures is considered the most prominent trait distinguishing it from the other foodborne pathogens. Within the infected host, the bacteria harbor inside macrophages and jump from cell to another without leaving the safeguarding milieu of the host's cells utilizing a set of genes including hly (listeriolysin O, plcA (phosphatidylinositol-specific phospholipase c, plcB (phosphatidylcholine-phospholipase C and actA (actin-assembly inducing protein. In addition to the health concerns associated with antibiotics, treatment failure likely occurs among listeriosis-infected persons especially with the inability of most antibiotics to access intracellular replicative niches and achieve the optimum therapeutic concentrations within the infected cells. Recently, one novel choice, peptide nucleic acid (PNA, has been emerged to target this bacterium as a model of targeting intracellular pathogens with anti-sense agents. PNA is a one of the DNA analogues which works via specific inhibition of bacterial gene expression.

  19. Silver as antibacterial towards Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    Simone eBelluco

    2016-03-01

    Full Text Available Listeria monocytogenes is a serious foodborne pathogen that can contaminate food during processing and can grow during food shelf-life. New types of safe and effective food contact materials embedding antimicrobial agents, like silver, can play an important role in the food industry. The present work aimed at evaluating the in vitro growth kinetics of different strains of L. monocytogenes in the presence of silver, both in its ionic and nano form. The antimicrobial effect was determined by assaying the number of culturable bacterial cells, which formed colonies after incubation in the presence of silver nanoparticles (AgNPs or silver nitrate (AgNO3. Ionic release experiments were performed in parallel. A different reduction of bacterial viability between silver ionic and nano forms was observed, with a time delayed effect exerted by AgNPs. An association between antimicrobial activity and ions concentration was shown by both silver chemical forms, suggesting the major role of ions in the antimicrobial mode of action.

  20. Generation of airborne Listeria innocua from model floor drains.

    Science.gov (United States)

    Berrang, Mark E; Frank, Joseph F

    2012-07-01

    Listeria monocytogenes can colonize floor drains in poultry processing and further processing facilities, remaining present even after cleaning and disinfection. Therefore, during wash down, workers exercise caution to avoid spraying hoses directly into drains in an effort to prevent the escape and transfer of drain microflora to food contact surfaces. The objective of this study was to examine the extent to which an inadvertent water spray into a colonized floor drain can cause the spread of airborne Listeria. Listeria innocua was used to inoculate a polyvinyl chloride model floor drain, resulting in approximately 10(8) cells per ml of phosphate-buffered saline and 10(4) attached cells per square centimeter of inner surface. Each model drain was subjected to a 2-s spray of tap water at 68.9 kPa from a distance of 1 m. Drains were sprayed while filled and again after emptying. Airborne cells were collected by using sedimentation plates containing Listeria selective agar which were placed on the floor and walls of a contained room at incremental horizontal and vertical distances of 0.6, 1.2, 2.4, or 4.0 m from the drain. Sedimentation plates were exposed for 10 min. A mechanical sampler was used to also collect air by impaction on the surface of Listeria selective agar to determine the number of cells per liter of air. The experiment was conducted in triplicate rooms for each of four replications. L. innocua was detected on sedimentation plates on the floor as far as 4.0 m from the drain and on walls as high as 2.4 m above the floor and 4 m from the drain. A 2-s spray with a water hose into a contaminated drain can cause airborne spread of Listeria, resulting in the potential for cross-contamination of food contact surfaces, equipment, and exposed product.

  1. Thermal resistance of Listeria monocytogenes in sausage meat.

    Science.gov (United States)

    Farber, J M; Hughes, A; Holley, R; Brown, B

    1989-01-01

    The heat resistance of a mixture of 10 different strains of Listeria monocytogenes inoculated into ground meat and ground meat plus cure was examined. D-values for ground meat ranged from 1.01 min at 62 degrees C to 13.18 min at 56 degrees C. The D-values obtained for ground meat plus cure were approximately 5-8 fold times higher than those for ground meat alone. These results imply that rare meats and possibly some cooked fermented meats may not be heated adequately to inactivate Listeria.

  2. [Listeria monocytogenes nosocomial infection in the maternity ward].

    Science.gov (United States)

    Jean, D; Croize, J; Hirtz, P; Legeais, C; Pelloux, I; Favier, M; Mallaret, M R; Le Noc, P; Rambaud, P

    1991-01-01

    Nosocomial infection with Listeria monocytogenes 4b occurred in January 1990 in a maternity hospital in Grenoble. The 3 patients involved were born within a 24 hour-interval. The premature newborn responsible for contamination was asymptomatic. Two other newborns without any perinatal infectious risk presented with meningitis, one on the 5th day of life in the maternity hospital, the other one on the 11th day while already at home. The 3 strains of Listeria had the same serovar and lysovar. Epidemiologic investigations led to suspect a contamination in the delivery room and during the care of the children. Strict respect of hygiene orders is imperative to avoid nosocomial infections.

  3. EFFICIENCY OF THE ENRICHMENT BROTHES (LEB1 AND LEB2 AND SELECTIVE AGARS (LPM AND LSAB-CAN TO ISOLATE BACTERIA OF THE GENUS Listeria IN MEAT AND RESIDUAL WATER OF WASHING CARCASS EFICIÊNCIA DOS CALDOS DE ENRIQUECIMENTO (LEB1 E LEB2 E DOS ÁGARES SELETIVOS (LPM E LSAB-CAN NO ISOLAMENTO DE BACTÉRIAS DO GÊNERO Listeria EM CARNE BOVINA E ÁGUA RESIDUÁRIA DE LAVAGEM DE CARCAÇA

    Directory of Open Access Journals (Sweden)

    Albenones José de Mesquita

    2007-09-01

    Full Text Available

    In this paper it was observed the efficiency of enrichment brothes for Listeria (LEB1 and LEB2, associated to the passage of the culture through a 0.25% potassium hidroxide solution, verifying that the secondary enrichment broth (LEB2 and LEB2KOH was better than the primary enrichment broth (LEB1KOH for this purpose. On the other hand, lithium chloride-phenylethanol-moxalactam agar and the selective Listeria agar base, supplemented with cicloheximide, acriflavine and nalidixic acid (LSAIB-CAN showed equivalency, at the statistic point of view (p=0.l442, in relation to the number of positive samples for Listeria spp., although the LSAB-CAN agar had given the greatest number of bacteria isolated from this genus.

    KEY-WORDS: Listeria; enrichment broth; selective agar.

    No presente trabalho verificou-se a eficiência dos caldos de enriquecimento para Listeria (LEB1 e LEB 2 associados à passagem da cultura por uma solução de hidróxido de potássio a 0,25%, constatando-se que o caldo de enriquecimento secundário (LEB2 e LEB2KOH foi superior ao caldo de enriquecimento primário (LEB1KOH. Por outro lado, o ágar cloreto de lítio-feniletanol-moxalactam (LPM e o ágar base seletivo para Listeria, suplementado com cicloheximida, acriflavina e ácido nalidíxico (LSAB-CAN equivaleram-se estatisticamente (p= 0,l442 em relação ao número de amostras positivas para Listeria, embora o ágar LSAB-CAN tenha proporcionado um maior número de isolamentos da bactéria.

    PALAVRAS-CHAVE: Caldo de enriquecimento; ágar seletivo; Listeria.

  4. Comparison of the Prevalences and Diversities of Listeria Species and Listeria monocytogenes in an Urban and a Rural Agricultural Watershed.

    Science.gov (United States)

    Stea, Emma C; Purdue, Laura M; Jamieson, Rob C; Yost, Chris K; Truelstrup Hansen, Lisbeth

    2015-06-01

    Foods and related processing environments are commonly contaminated with the pathogenic Listeria monocytogenes. To investigate potential environmental reservoirs of Listeria spp. and L. monocytogenes, surface water and point source pollution samples from an urban and a rural municipal water supply watershed in Nova Scotia, Canada, were examined over 18 months. Presumptive Listeria spp. were cultured from 72 and 35% of rural and urban water samples, respectively, with 24% of the positive samples containing two or three different Listeria spp. The L. innocua (56%) and L. welshimeri (43%) groups were predominant in the rural and urban watersheds, respectively. Analysis by the TaqMan assay showed a significantly (P monocytogenes of 62% versus 17% by the culture-based method. Both methods revealed higher prevalences in the rural watershed and during the fall and winter seasons. Elevated Escherichia coli (≥ 100 CFU/100 ml) levels were not associated with the pathogen regardless of the detection method. Isolation of Listeria spp. were associated with 70 times higher odds of isolating L. monocytogenes (odds ratio = 70; P monocytogenes isolates, followed by IVb (16.1%), IIb (15.8%), and IIc (0.4%). L. monocytogenes was detected in cow feces and raw sewage but not in septic tank samples. Pulsotyping of representative water (n = 54) and local human (n = 19) isolates suggested genetic similarities among some environmental and human L. monocytogenes isolates. In conclusion, temperate surface waters contain a diverse Listeria species population and could be a potential reservoir for L. monocytogenes, especially in rural agricultural watersheds. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  5. Various Ready-to-Eat Products from Retail Stores Linked to Occurrence of Diverse Listeria monocytogenes and Listeria spp. Isolates.

    Science.gov (United States)

    Vongkamjan, Kitiya; Fuangpaiboon, Janejira; Turner, Matthew P; Vuddhakul, Varaporn

    2016-02-01

    Listeriosis outbreaks have been associated with a variety of foods. This study investigated the prevalence and diversity of Listeria monocytogenes and Listeria spp. in ready-to-eat (RTE) products and evaluated the performance of a rapid detection method, the 3M molecular detection assay for L. monocytogenes (MDA-LM), for detection of L. monocytogenes. Assay results were compared with those obtained using the U.S. Food and Drug Administration standard culture method described in the Bacteriological Analytical Manual. Products (n = 200) were purchased from retail stores: 122 aquatic products, 22 products of animal origin, 18 vegetarian products, 15 deli meat products, 13 salad and vegetable products, 4 desserts, 2 egg-based products, and 4 other products. L. monocytogenes prevalence was comparable with both methods. Overall, 15 (7.5%) of 200 samples were positive for L. monocytogenes: 3% of aquatic products, 1.5% of products of animal origin, 1% of vegetarian products, and 2% of deli meat products. Compared with the standard culture method, the sensitivity, specificity, and the accuracy of the MDA-LM were 86.7% (95% confidence interval, 58.4 to 97.7%), 98.4% (95% confidence interval, 95.0 to 99.6%), and 97.5%, respectively. Using the culture-based method, 18 (9%) of 200 samples were positive for Listeria species other than L. monocytogenes. Listeria isolates from these samples were classified into nine allelic types (ATs). The majority of isolates were classified as ATs 58 and 74, which were identified as L. monocytogenes lineages I and IV, respectively. Listeria innocua and Listeria welshimeri also were represented by isolates of multiple ATs. The MDA-LM is a rapid and reliable technique for detecting L. monocytogenes in various RTE foods. Further study is needed to develop effective control strategies to reduce L. monocytogenes contamination in RTE foods.

  6. Listeria monocytogenes en alimentos: ¿son todos los aislamientos igual de virulentos? Foodborne Listeria monocytogenes: are all the isolates equally virulent?

    Directory of Open Access Journals (Sweden)

    V. López

    2006-12-01

    Full Text Available Listeria monocytogenes es un patógeno humano que se transmite a través de los alimentos y que causa infecciones graves, con una alta tasa de mortalidad. A pesar de la ubicuidad del microorganismo, la tasa real de la enfermedad es bastante baja y se asocia casi siempre a condiciones predisponentes. Tradicionalmente se consideraba que los aislamientos presentes en los alimentos y en el ambiente tenían la misma capacidad patogénica que los aislamientos de origen clínico. Pero el análisis de mutaciones en los genes de determinados factores de virulencia (internalina, hemolisina, fosfolipasas, proteína de superficie ActA y proteína reguladora PrfA, los estudios cuantitativos realizados con cultivos celulares y la genética de poblaciones, están replanteando la discusión sobre la variabilidad de la virulencia de L. monocytogenes. A pesar de todos estos avances, no existe un único marcador que permita comprobar la virulencia de los aislamientos naturales de esta especie. Probablemente en el futuro, la combinación de diferentes marcadores moleculares permitirá detectar los alimentos contaminados sólo por los clones virulentos de L. monocytogenes, con lo que se mejorará la prevención de la listeriosis humana transmitida por alimentos.Listeria monocytogenes is a foodborne human pathogen responsible for invasive infections presenting overall a high mortality. Despite the ubiquity of the microorganism, the actual disease rate is quite low and the disease is most often associated with an underlying predisposition. Foodborne and environmental isolates were traditionally considered of similar pathogenicity compared to clinical isolates. But the analysis of mutations in the genes encoding specific virulence factors (internalin, hemolysin, phospholipases, surface protein ActA and regulator protein PrfA, quantitative studies with cell cultures and population genetics have raised considerable concerns about virulence differences among L

  7. Comparative experimental infection of Listeria monocytogenes and Listeria ivanovii in bovine trophoblasts.

    Science.gov (United States)

    Rocha, Cláudia E; Mol, Juliana P S; Garcia, Luize N N; Costa, Luciana F; Santos, Renato L; Paixão, Tatiane A

    2017-01-01

    Listeria monocytogenes is a Gram-positive, facultative intracellular and invasive bacterium that has tropism to the placenta, and causes fetal morbidity and mortality in several mammalian species. While infection with L. monocytogenes and L. ivanovii are known as important causes of abortion and reproductive failure in cattle, the pathogenesis of maternal-fetal listeriosis in this species is poorly known. This study used the bovine chorioallantoic membrane explant model to investigate the kinetics of L. monocytogenes, L. ivanovii, and L. innocua infections in bovine trophoblastic cells for up to 8 h post infection. L. monocytogenes and L. ivanovii were able to invade and multiply in trophoblastic cells without causing cell death or inducing expression of pro-inflammatory genes. Although L. innocua was unable to multiply in bovine trophoblastic cells, it induced transcription of the pro-inflammatory mediator CXCL6. This study demonstrated for the first time the susceptibility of bovine trophoblastic cells to L. monocytogenes and L. ivanovii infection.

  8. Survival strategies of Listeria monocytogenes - roles of regulators and transporters

    NARCIS (Netherlands)

    Wemekamp-Kamphuis, H.H.

    2003-01-01

    Outbreaks of the food-borne pathogen Listeria monocytogenes are mainly associated with ready-to-eatfoods. Survival strategies of L. monocytogenes in relation to minimally processed foods were studied.

  9. Incidence and control of Listeria monocytogenes in foods in Denmark

    DEFF Research Database (Denmark)

    Nørrung, Birgit; Andersen, Jens Kirk; Schlundt, Jørgen

    1999-01-01

    The Danish regulatory policy on Listeria monocytogenes in foods is based on the principles of HACCP and was developed using a health risk assessment approach. The Danish policy focuses examinations and criteria for L. monocytogenes in ready-to-eat foods and is based on a combination of inspection...

  10. Overlevingsstrategieën Listeria monocytogenes bij lage temperatuur

    NARCIS (Netherlands)

    Wemekamp-Kamphuis, H.H.; Abee, T.

    2004-01-01

    Listeria monocytogenes is an important food-borne pathogen that may cause severe infections in humans. Many outbreaks caused by this organism have been associated with ready-to-eat foods wich may have undergone some form of minimal processing, or have been contaminated after processing. Ready-to-eat

  11. 21 CFR 172.785 - Listeria-specific bacteriophage preparation.

    Science.gov (United States)

    2010-04-01

    ... application to meat and poultry products that comply with the ready-to-eat definition in 9 CFR 430.1. Current... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Listeria-specific bacteriophage preparation. 172.785 Section 172.785 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN...

  12. GROWTH OF NATURALLY OCCURING Listeria innocua IN COPPA DI TESTA

    Directory of Open Access Journals (Sweden)

    G. Merialdi

    2010-06-01

    Full Text Available Coppa di testa is a traditional cooked pork salami produced in different Italian regions. The main raw material is deboned meat of pork head with the addition of tongue and rind. After a long (3-5 h high temperature (97°C cooking, additives and flavourings are added and the salami is prepared. After cooling the salami is often portioned and vacuum- packaged. In this study the growth of naturally occurring contamination of Listeria innocua in three batches of vacuum packaged Coppa di testa, stored at 4°C for 80 days, is described. The average max was 0.24 (days-1 and the average doubling time was 2.87 days. The maximum growth level ranged from 4.90 to 8.17 (log10 cfu/g. These results indicate that Coppa di testa definitely supports the growth of Listeria innocua in the considered storage conditions. Taking into account that at 4°C Listeria monocytogenes strains are associated with higher grow rates than L. innocua, these results emphasize the importance of preventing Listeria monocytogenes contamination in the production stages following cooking.

  13. Listeria monocytogenes internalizes in Romaine Lettuce grown in greenhouse conditions

    Science.gov (United States)

    Listeria monocytogenes has been implicated in a number of outbreaks involving fresh produce, including an outbreak in 2016 resulting from contaminated packaged salads. The persistence and internalization potential of L. monocytogenes in romaine lettuce was evaluated, and the persistence of two L. mo...

  14. Microbial quality and prevalence of Salmonella and Listeria in eggs

    Directory of Open Access Journals (Sweden)

    Manijeh Mahdavi

    2012-01-01

    Full Text Available Aims: This study was undertaken to determine the microbial quality and the prevalence of Salmonella and Listeria in table eggs in Isfahan, Iran. Materials and Methods: A total of 525 samples were randomly collected from various shops in Isfahan, Iran. Microbial quality of eggs evaluated by coliform count and total bacterial viable counts. Also, detection of Listeria and Salmonella in egg contents and on eggs shells was performed. Results: The mean of total viable bacteria and coliform counts in the egg contents were 3.95 × 10 4 CFU/g and 4.94 × 10 3 CFU/g, respectively. Salmonella and Listeria were not found on the shell or content of eggs. Enterobacteriaceae families were found in 357 of 525 (68.28% and 276 of 525 (52.44% of egg shell and egg content samples, respectively. Moreover, Pseudomonas aeruginosa was isolated from 175 (33.41% and 144 (25.37% of egg shell and egg content, respectively. The isolated Enterobacteriaceae were included: Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, Buttiauxella agrestis, Cedecea lapagei, Cedecea davisae and Erwinia herbicola. Conclusion: The findings of the present study indicate although Salmonella and Listeria were not found in egg samples; however, there is an urgent need to improve the hygienic level of consumed eggs.

  15. Occurrence of Listeria monocytogenes in smoked fish in Sokoto ...

    African Journals Online (AJOL)

    The present study was conducted to determine the prevalence of Listeria monocytogenes in smoked fish in Sokoto, Nigeria. A total of 115 different species of smoked fish from the various retail outlets and market places within the metropolis were analysed for the presence of L. monocytogenes using ISO culture method.

  16. Isolation and characterisation of Listeria species from ruminants in ...

    African Journals Online (AJOL)

    A cross sectional study was carried out to determine the prevalence of Listeria species in ruminants in Maiduguri. Three hundred faecal samples were randomly collected from ruminants at the Maiduguri central abattoir from January – March, 2011. One hundred faecal samples each were collected from cattle, sheep and ...

  17. Enterocin CRL35 inhibits Listeria monocytogenes in a murine model.

    Science.gov (United States)

    Salvucci, Emiliano; Saavedra, Lucila; Hebert, Elvira Maria; Haro, Cecilia; Sesma, Fernando

    2012-01-01

    Listeria monocytogenes is a foodborne pathogen causative of opportunistic infections. Listeriosis is associated with severe infections in pregnant women causing abortion or neonatal listeriosis. An alternative to antibiotics are safe novel bacteriocins peptides such as enterocin CRL35 with strong antilisterial activity produced by Enterococcus mundtii CRL35. In the present paper, our goal is to study the effectiveness of this peptide and the producer strain in a murine model of pregnancy-associated listeriosis. A single dose of 5×10(9) colony-forming unit of L. monocytogenes FBUNT (Faculty of Biochemistry-University of Tucumán) resulted in translocation of pathogen to liver and spleen of BALB/c pregnant mice. The maximum level of Listeria was observed on day 3 postinfection. Interestingly, the intragastric administration of enterocin CRL35 significantly reduced the translocation of the pathogen to vital organs. On the other hand, the preadministration of E. mundtii CRL35 slightly inhibited this translocation. Listeria infection caused a significant increase in polymorphonuclear leukocytes at day 3 postinfection compared to the noninfected group. This value was reduced after the administration of enterocin CRL35. No significant changes were observed in either white blood cells or lymphocytes counts. Based on the data presented in the present work enterocin CRL35 would be a promising alternative for the prevention of Listeria infections.

  18. Listeria monocytogenes repellence by enzymatically modified PES surfaces

    NARCIS (Netherlands)

    Veen, van der S.; Nady, N.; Franssen, M.C.R.; Zuilhof, H.; Boom, R.M.; Abee, T.; Schroën, C.G.P.H.

    2015-01-01

    : The effect of enzyme-catalyzed modification of poly(ethersulfone) (PES) on the adhesion and biofilm formation of two Listeria monocytogenes strains is evaluated under static and dynamic flow conditions. PES has been modified with gallic acid, ferulic acid and 4-hydroxybenzoic acid. The surfaces

  19. Listeria monocytogenes infection in pregnancy and neonatal sepsis

    Directory of Open Access Journals (Sweden)

    Francesca Pascale

    2008-06-01

    Full Text Available Authors report a fatal neonatal sepsis caused by Listeria monocytogenes. While the diagnostic procedure aimed to identify the microrganism is described, it is emphasized the importance to recover Streptococcus agalactiae (GBS and L. monocytogenes by means of vaginal-rectal swab culture. The intrapartum screening for L. monocytogenes, by Polymerase Chain Reaction (PCR providing results in 75 minutes is also evaluated.

  20. LISTERIA MONOCYTOGENES IN THE CONTEXT OF THE NEW COMMUNITY REGULATIONS

    Directory of Open Access Journals (Sweden)

    A. Bragagnolo

    2008-02-01

    Full Text Available In recent years in the countries of the European Union have occurred profound and radical changes regarding the safety and hygiene of foodstuffs. The aim of this work is to highlight the significant changes made by the recent legislation in the control of Listeria monocytogenes.

  1. Antibiotic resistant pattern of environmental isolates of Listeria ...

    African Journals Online (AJOL)

    Incidence of Listeria monocytogenes in cow manure, agricultural soil, and common vegetables sold in major markets in Ado-Ekiti, Nigeria was determined. Antibiotic resistant pattern of the isolates was examined by paper disk assay. A total of 196 environmental samples were cultured on a selective medium out of which ...

  2. Genome sequences of Listeria monocytogenes strains with resistance to arsenic

    Science.gov (United States)

    Listeria monocytogenes frequently exhibits resistance to arsenic. We report here the draft genome sequences of eight genetically diverse arsenic-resistant L. monocytogenes strains from human listeriosis and food-associated environments. Availability of these genomes would help to elucidate the role ...

  3. Influence of temperature on alkali stress adaptation in Listeria monocytogenes

    Science.gov (United States)

    Listeria monocytogenes cells may induce alkali stress adaptation when exposed to sublethal concentrations of alkaline cleaners and sanitizers that may be frequently used in the food processing environment. In the present study, the effect of temperature on the induction and the stability of such alk...

  4. Activity of daptomycin against Listeria monocytogenes isolates from cerebrospinal fluid

    NARCIS (Netherlands)

    Spanjaard, Lodewijk; Vandenbroucke-Grauls, Christina M. J. E.

    2008-01-01

    We tested the activity of daptomycin against 76 Listeria monocytogenes isolates from cerebrospinal fluid by broth dilution and Etest methods. For the broth dilution method, the MIC range was 1.0 to 8.0 and the MIC at which 90% of the isolates tested were inhibited (MIC(90)) was 4.0 mg/liter. For the

  5. Listeria monocytogenes growth limits and stress resistance mechanisms

    NARCIS (Netherlands)

    Veen, van der S.

    2008-01-01

    The food-borne pathogen Listeria monocytogenes is a Gram-positive facultative anaerobic rod, which is the causative agent of listeriosis. Due to the severity of the disease and the fact that its incidence is increasing in numerous European countries, L. monocytogenes is of great public health

  6. Resistance of Listeria monocytogenes biofilms to sanitizing agents

    Science.gov (United States)

    Listeria monocytogenes is notorious for its capacity to colonize the environment and equipment of food processing facilities and to persist in the processing plant ecosystem, sometimes for decades. Such persistence is mediated by multiple attributes of L. monocytogenes, including the pathogen’s capa...

  7. Antimicrobial susceptibility profile of Listeria species isolated from ...

    African Journals Online (AJOL)

    The antimicrobial susceptibility profile of L. monocytogenes and other Listeria species isolated from some ready-to-eat (RTE) foods sold in Kano metropolis, north-western Nigeria was carried out using disc-diffusion method. The results obtained showed that L. monocytogenes was moderately susceptible to all the ...

  8. Formation of biofilm by strains of Listeria monocytogenes isolated ...

    African Journals Online (AJOL)

    Quantification of biofilm formation by 40 Listeria monocytogenes strains from wara soft cheese and its processing environment was assessed on glass vials surfaces. Attachement to glass surface was quantified using a crystal violet binding assay. All the 40 strains produced biofilms after 48 and 72 h incubation at 37oC.

  9. Pathogenic potential of Listeria monocytogenes isolated from cattle ...

    African Journals Online (AJOL)

    Listeria monocytogenes is an opportunistic food-borne pathogen causing listeriosis especially among immune-compromised persons. Its high rate of morbidity and mortality has classed the organism among the top watch list in foods. It is known to produce several virulence factors which aid its survival in harsh conditions ...

  10. Monitoring paneer for Listeria monocytogenes - A high risk food ...

    African Journals Online (AJOL)

    A multiplex polymerase chain reaction (PCR) assay was developed and applied to spiked and natural paneer samples to detect Listeria monocytogenes, a high risk food pathogen. The sensitivity of the assay on L. monocytogenes spiked paneer samples was 104 cells prior to enrichment, was improved to 103 cells after 4 h ...

  11. Prevalence and antibiotic susceptibility of Listeria monocytogenes in ...

    African Journals Online (AJOL)

    One hundred and ninety two raw milk samples were collected from lactating cows identified in Fulani herds and small scale dairy farms within Sokoto metropolis in order to investigate the presence and determine the antibiotic susceptibility of Listeria monocytogenes in the milk. Selective culture and identification method ...

  12. Listeria spp. E Listeria monocytogenes NA PRODUÇÃO DE SALSICHAS TIPO HOT DOG

    Directory of Open Access Journals (Sweden)

    ALESSANDRA PARO RODRIGUES CESAR

    2011-06-01

    Full Text Available Listeria monocytogenes is widely distributed in the environment and it has been isolated from food that were associated to outbreaks of high lethality in many countries. Thus, this bacterium represents an important pathogen to the public health. Ready-to-eat products, likecooked stuffed food, within them, frankfurters, are associated to human listeriosis in many countries. Taking into consideration the importance of the subject and the need of more data about it, the occurrence of Listeria spp. and L. monocytogenes in industrial plants, in meat raw materials, in slurry and frankfurters was investigated.These samples were collected in two production plants with SIF (Federal Inspection Service; in one of them GMP, HACCP and SOP were implemented. The results of the 1 06 microbiological analysis were submitted to the program @Risk to obtain the risk analysis; the meanvalues results showed that 7 to 9% of the frankfurters in the market may have L. monocytogenes. The analysis indicated that 88 strains of L. monocytogenes were obtained from 1 06 samples; among them, 76 werecollected in the industrial plants that participate in the experiment, and 30 were collected in the market. In serological typification, 95% of these strains were classified as serotypes 4b, 1 /2a and 1 /2b. Besides the presence of the bacterium in frankfurthers consumed inBrazil and the risk factors associated to this pathogen, the situation concerns because of the lack of epidemiological data, absence of patterns and the deficient information given to the consumer, specially information related to the presence of L. monocytogenes, particularly important to the groups at risk, as well as information related to the importance of heating the product

  13. Listeria spp. associated to different levels of autochthonous microbiota in meat, meat products and processing plants Listeria spp. associado a diferentes níveis da microbiota autóctone de carne, produtos cárneos e plantas de processamento

    Directory of Open Access Journals (Sweden)

    Márcia de Aguiar Ferreira Barros

    2007-12-01

    Full Text Available High levels of microbial contamination, commonly found in animal origin foods and food processing environments, are able to hinder the growth of pathogens in these products and interfere in the results of laboratory analyses for detection of these pathogens. With the aim of verifying the possible interference of the autochthonous microbiota encountered in meat and meat products and processing plants over the presence of Listeria spp., 443 samples, collected from 11 meat retail establishments, were submitted to microbiological analysis to determine the levels of mesophilic aerobes, total coliforms and Escherichia coli and the presence of Listeria spp., according to the methodology proposed by the USDA. The results did not show evident interference of the autochthonous microbiota over Listeria spp., once the genus was detected even in the meat, meat products and environmental samples with high levels of contamination by mesophilic aerobes and coliforms.Altos níveis de contaminação microbiana, usualmente encontrados em alimentos de origem animal e nos ambientes de processamento, podem inibir a multiplicação de microrganismos patogênicos nesses produtos e interferir nos resultados das análises laboratoriais para o isolamento desses patógenos. Com o objetivo de verificar as possíveis interferências da microbiota autóctone encontrada na carne, produtos cárneos e plantas de processamento sobre a presença de Listeria spp., 443 amostras, coletadas em 11 estabelecimentos processadores, foram submetidas a análises microbiológicas para determinação dos níveis de contaminação por aeróbios mesófilos, coliformes totais e Escherichia coli e para verificação da presença de Listeria spp., de acordo com a metodologia proposta pelo USDA. Os resultados obtidos não mostraram uma interferência evidente da microbiota autóctone sobre Listeria spp., uma vez que esse gênero foi detectado mesmo nas amostras de carne e produtos cárneos e

  14. Rapid identification and classification of Listeria spp. and serotype assignment of Listeria monocytogenes using fourier transform-infrared spectroscopy and artificial neural network analysis

    Science.gov (United States)

    The use of Fourier Transform-Infrared Spectroscopy (FT-IR) in conjunction with Artificial Neural Network software, NeuroDeveloper™ was examined for the rapid identification and classification of Listeria species and serotyping of Listeria monocytogenes. A spectral library was created for 245 strains...

  15. Phenotypic and Genotypic Characterization of Atypical Listeria monocytogenes and Listeria innocua Isolated from Swine Slaughterhouses and Meat Markets

    Directory of Open Access Journals (Sweden)

    Luisa Zanolli Moreno

    2014-01-01

    Full Text Available In the last decade, atypical Listeria monocytogenes and L. innocua strains have been detected in food and the environment. Because of mutations in the major virulence genes, these strains have different virulence intensities in eukaryotic cells. In this study, we performed phenotypic and genotypic characterization of atypical L. monocytogenes and L. innocua isolates obtained from swine slaughterhouses and meat markets. Forty strains were studied, including isolates of L. monocytogenes and L. innocua with low-hemolytic activity. The isolates were characterized using conventional phenotypic Listeria identification tests and by the detection and analysis of L. monocytogenes-specific genes. Analysis of 16S rRNA was used for the molecular identification of the Listeria species. The L. monocytogenes isolates were positive for all of the virulence genes studied. The atypical L. innocua strains were positive for hly, plcA, and inlC. Mutations in the InlC, InlB, InlA, PI-PLC, PC-PLC, and PrfA proteins were detected in the atypical isolates. Further in vitro and transcriptomic studies are being developed to confirm the role of these mutations in Listeria virulence.

  16. Prevalence of Listeria monocytogenes and other Listeria species in butter from United Kingdom production, retail, and catering premises.

    Science.gov (United States)

    Lewis, H C; Little, C L; Elson, R; Greenwood, M; Grant, K A; McLauchlin, J

    2006-07-01

    Two recent listeriosis outbreaks involving butter prompted this first cross-sectional study on the prevalence, levels, and types of Listeria species in 3229 samples of butter from production, retail, and catering premises in the United Kingdom during May and June 2004. When the criteria of the Microbiological Guidelines were used, 99.4% of samples were found to be of satisfactory microbiological quality, 0.5% were of acceptable quality, and 0.1% were of unsatisfactory quality as a result of high levels (>100 CFU/g) of Listeria spp. The butter samples with Listeria spp. present at more than 100 CFU/g were negative for L. monocytogenes. L. monocytogenes was detected in 0.4% (n=13) of samples, all at levels of less than 10 CFU/g, and were therefore of acceptable quality. Butter was contaminated more frequently with Listeria spp., including L. monocytogenes, when packed in plastic tubs, when in pack sizes of 500 g or less, when stored or displayed above 8 degrees C, when a hazard analysis system was not in place, and when the manager had received no food hygiene training. This study demonstrates that although butter is regarded as a low-risk product, it may provide an environment for the persistence and growth of Listeria spp., including L. monocytogenes. The control of L. monocytogenes in food processing and supply systems is critical in order to minimize the potential for this bacterium to be present in foods at the point of consumption at levels hazardous to health.

  17. Prevalence, antimicrobial susceptibility and virulotyping of Listeria species and Listeria monocytogenes isolated from open-air fish markets.

    Science.gov (United States)

    Jamali, Hossein; Paydar, Mohammadjavad; Ismail, Salmah; Looi, Chung Yeng; Wong, Won Fen; Radmehr, Behrad; Abedini, Atefeh

    2015-07-25

    The aim of this study was to investigate the prevalence and characterization of Listeria species and Listeria monocytogenes isolated from raw fish and open-air fish market environments. Eight hundred and sixty two samples including raw fish and fish market environments (samples from workers' hands, workers' knives, containers and work surface) were collected from the open-air fish markets in the Northern region of Iran. Listeria spp. was isolated from 104/488 (21.3%) raw fish and 29/374 (7.8%) of samples from open-air fish market environment. The isolates of Listeria spp. included L. innocua (35.3%), L. monocytogenes (32.3%), L. seeligeri (18%), and L. ivanovii (14.3%). Of the 43 L. monocytogenes isolates, 31 (72.1%), 10 (23.3%) and 2 (4.7%) belonged to serovars 1/2a, 4b, and 1/2b, respectively. The inlA, inlB, inlC, inlJ, actA, hlyA, iap, plcA, and prfA virulence-associated genes were detected in almost all of the L. monocytogenes isolates. The Listeria spp. isolates showed high resistance against tetracycline (23.3%), penicillin G, and cephalothin (each 16.5%). Besides, we observed significant resistance level to tetracycline (27.9%), ampicillin (20.9%), cephalothin, penicillin G, and streptomycin (each 16.3%) in the L. monocytogenes isolates. All of the isolates were susceptible to cefotaxime, gentamicin, kanamycin, and pefloxacin. We found that tetM (25.6%), tetA (23.3%), ampC (14%), and penA (11.6%) were the most prevalent antibiotic resistance genes in the L. monocytogenes isolates. Recovery of potentially pathogenic L. monocytogenes from raw fish and environment of open-air fish market samples in this study is a convincing evidence for the zoonotic potential of listeriosis.

  18. Antimicrobial susceptibility and antibiotic resistance gene transfer analysis of foodborne, clinical, and environmental Listeria spp. isolates including Listeria monocytogenes.

    Science.gov (United States)

    Bertsch, David; Muelli, Mirjam; Weller, Monika; Uruty, Anaïs; Lacroix, Christophe; Meile, Leo

    2014-02-01

    The aims of this study were to assess antibiotic resistance pheno- and genotypes in foodborne, clinical, and environmental Listeria isolates, as well as to elucidate the horizontal gene transfer potential of detected resistance genes. A small fraction of in total 524 Listeria spp. isolates (3.1%) displayed acquired antibiotic resistance mainly to tetracycline (n = 11), but also to clindamycin (n = 4) and trimethoprim (n = 3), which was genotypically confirmed. In two cases, a tetracycline resistance phenotype was observed together with a trimethoprim resistance phenotype, namely in a clinical L. monocytogenes strain and in a foodborne L. innocua isolate. Depending on the applied guidelines, a differing number of isolates (n = 2 or n = 20) showed values for ampicillin that are on the edge between intermediate susceptibility and resistance. Transferability of the antibiotic resistance genes from the Listeria donors, elucidated in vitro by filter matings, was demonstrated for genes located on transposons of the Tn916 family and for an unknown clindamycin resistance determinant. Transfer rates of up to 10(-5) transconjugants per donor were obtained with a L. monocytogenes recipient and up to 10(-7) with an Enterococcus faecalis recipient, respectively. Although the prevalence of acquired antibiotic resistance in Listeria isolates from this study was rather low, the transferability of these resistances enables further spread in the future. This endorses the importance of surveillance of L. monocytogenes and other Listeria spp. in terms of antibiotic susceptibility. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  19. Applicability of the EN ISO 11290-1 standard method for Listeria monocytogenes detection in presence of new Listeria species.

    Science.gov (United States)

    Barre, Léna; Angelidis, Apostolos S; Boussaid, Djouher; Brasseur, Emilie Decourseulles; Manso, Eléonore; Gnanou Besse, Nathalie

    2016-12-05

    During the past six years, new species of the genus Listeria have been isolated from foods and other environmental niches worldwide. The Standard method EN ISO 11290-1 that is currently under revision will include in its scope all Listeria species in addition to L. monocytogenes. The objective of this project was to evaluate the ability of the Standard EN ISO 11290-1 method to detect and identify the newly discovered Listeria spp., and to assess potential over-growth effects of the new species in mixed cultures with L. monocytogenes during each step of the enrichment process. This objective was addressed by the generation of necessary data on the behavior of the new species during the pre-enrichment and the enrichment steps of the reference method as well as data on their phenotypic characteristics on rich and selective media used for isolation and identification. Most of the new Listeria species developed well on selective agar media for Listeria, however the recovery of some species was difficult due to poor growth in Half Fraser and Fraser broth. Good results (consistently positive) were obtained for confirmation at the genus level via the catalase test, the Gram test and the blueish appearance test on non-selective medium, but not with the VP test, as most of the new species yielded a negative result. In the light of results obtained in co-culture experiments and inhibition tests, and considering the growth rates in Half Fraser and Fraser broths, the new species do not seem to interfere with the detection of L. monocytogenes. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Virulencia de cepas de Listeria monocytogenes procedentes de cabras y sus derivados

    Directory of Open Access Journals (Sweden)

    Guicela Ramírez Bernal

    2014-01-01

    Full Text Available Se evaluó la virulencia de cepas de Listeria monocytogenes todas de serotipo 4b procedentes de cabras y sus derivados. Se observaron niveles de virulencia variables cuando se comparó la virulencia relativa (porcentaje de letalidad en ratones BALB/c inoculados vía intravenosa o intragástrica y su capacidad para infectar macrófagos J774A.1, y células epiteliales Caco-2. Dos cepas obtenidas de alimento de cabras produjeron 100 % de letalidad por ambas vías de inoculación y no mostraron diferencia significativa con la cepa testigo (P>0.05 respecto al porcentaje de invasión y a los parámetros de la cinética de crecimiento cuadrática observada en ambas líneas celulares. Si bien todas las cepas lograron invadir las células Caco-2, solamente algunas consiguieron invadir el bazo después de la inoculación por vía intragástrica. Las dos cepas provenientes de alimento de cabras fueron las más virulentas, representando un riesgo para la salud humana y animal, ya que pueden ser diseminadas en el hato y de este a otras explotaciones o a las instalaciones donde se elaboran alimentos.

  1. Listeria monocytogenes en alimentos: ¿son todos los aislamientos igual de virulentos?

    Directory of Open Access Journals (Sweden)

    V. López

    Full Text Available Listeria monocytogenes es un patógeno humano que se transmite a través de los alimentos y que causa infecciones graves, con una alta tasa de mortalidad. A pesar de la ubicuidad del microorganismo, la tasa real de la enfermedad es bastante baja y se asocia casi siempre a condiciones predisponentes. Tradicionalmente se consideraba que los aislamientos presentes en los alimentos y en el ambiente tenían la misma capacidad patogénica que los aislamientos de origen clínico. Pero el análisis de mutaciones en los genes de determinados factores de virulencia (internalina, hemolisina, fosfolipasas, proteína de superficie ActA y proteína reguladora PrfA, los estudios cuantitativos realizados con cultivos celulares y la genética de poblaciones, están replanteando la discusión sobre la variabilidad de la virulencia de L. monocytogenes. A pesar de todos estos avances, no existe un único marcador que permita comprobar la virulencia de los aislamientos naturales de esta especie. Probablemente en el futuro, la combinación de diferentes marcadores moleculares permitirá detectar los alimentos contaminados sólo por los clones virulentos de L. monocytogenes, con lo que se mejorará la prevención de la listeriosis humana transmitida por alimentos.

  2. Prevalence of Listeria Species in Ready-to-Eat Food in Shahrekord Restaurants

    OpenAIRE

    Rahimi, E; Shakerian, A. (PhD

    2014-01-01

    Background and Objective: Listeria bacteria with worldwide widespread are commonly found in soil, sewage, dust and water. Among which,Listeria monocytogenes can cause a serious food-borne disease. The objective of this study was to investigate the prevalence of Listeria species in ready-to-eat foods. Material and Methods: The samples (n=235) including oloveyh salad (n = 64), Yogurt stew (n= 35), vegetable salad (n=52), macaroni salad (n= 48) and meat salad (n =36) were collected from the rest...

  3. Cytopathogenic effects in enterocytelike Caco-2 cells differentiate virulent from avirulent Listeria strains.

    OpenAIRE

    Pine, L; Kathariou, S; Quinn, F; George, V; Wenger, J D; Weaver, R E

    1991-01-01

    We have developed a simple test that differentiates between virulent and avirulent Listeria species as defined by the mouse 50% lethal doses (LD50S). The assay is based on trypan blue-revealed cytopathogenic effects that are produced during the infection of the human enterocytelike cell line Caco-2. These effects were elicited only by Listeria strains that had an intraperitoneal mouse LD50 less than 10(8) and were not produced by nonhemolytic, avirulent strains of Listeria monocytogenes gener...

  4. Geographical and meteorological factors associated with isolation of Listeria species in New York State produce production and natural environments.

    Science.gov (United States)

    Chapin, Travis K; Nightingale, Kendra K; Worobo, Randy W; Wiedmann, Martin; Strawn, Laura K

    2014-11-01

    Listeria species have been isolated from diverse environments, often at considerable prevalence, and are known to persist in food processing facilities. The presence of Listeria spp. has been suggested to be a marker for Listeria monocytogenes contamination. Therefore, a study was conducted to (i) determine the prevalence and diversity of Listeria spp. in produce production and natural environments and (ii) identify geographical and/or meteorological factors that affect the isolation of Listeria spp. in these environments. These data were also used to evaluate Listeria spp. as index organisms for L. monocytogenes in produce production environments. Environmental samples collected from produce production (n = 588) and natural (n = 734) environments in New York State were microbiologically analyzed to detect and isolate Listeria spp. The prevalence of Listeria spp. was approximately 33 and 34% for samples obtained from natural environments and produce production, respectively. Co-isolation of L. monocytogenes and at least one other species of Listeria in a given sample was recorded for 3 and 9% of samples from natural environments and produce production, respectively. Soil moisture and proximity to water and pastures were highly associated with isolation of Listeria spp. in produce production environments, while elevation, study site, and proximity to pastures were highly associated with isolation of Listeria spp. in natural environments, as determined by randomForest models. These data show that Listeria spp. were prevalent in both agricultural and nonagricultural environments and that geographical and meteorological factors associated with isolation of Listeria spp. were considerably different between the two environments.

  5. The Presence and Prevalence of Listeria Species in Milk and Herby Cheese in and Around Van

    OpenAIRE

    SAĞUN, Emrullah; SANCAK, Yakup Can; İŞLEYİCİ, Özgür; EKİCİ, Kamil

    2014-01-01

    In this study 250 raw milk and 254 herby cheese samples collected from Van city center and neighboring villages were investigated in terms of Listeria species. For Listeria isolation,the method recommended by the FDA was used.Of the raw milk samples,6 (2.40 %)were found to be positive with regard to Listeria; 3 (1.20 %)had L.monocytogenes, 1 (0.40 %)L.innocua and 1 (0.40 %)L.welshimeri. Of the herby cheese samples,13 (5.11 %)were found to be positive with regard to Listeria;10 (3.93 %)had...

  6. Contamination profile of Listeria spp. in three types of ready-to-eat chicken meat products.

    Science.gov (United States)

    Lekroengsin, Sumalin; Keeratipibul, Suwimon; Trakoonlerswilai, Kasame

    2007-01-01

    This study investigated contamination sources of Listeria spp. in frozen, ready-to-eat, roasted, steamed, and fried chicken meat products from a plant in Thailand, as well as the correlation between Listeria contamination in the production environment and the finished product. The cooking processes used in this factory (with a product core temperature of 80 degrees C for 1 min) were confirmed as adequate for eliminating Listeria spp. However, Listeria spp. were detected at the packing stage of roasted and steamed chicken products. An environmental swab test was conducted by means of the zone concept, whereby surfaces in the production area were divided into three zones. Zone 1 was made up of the equipment surfaces that came into direct contact with the products. Zone 2 consisted of equipment surfaces that were not in direct contact with the products, including surfaces that were difficult to be cleaned. Zone 3 included surfaces that did not come in direct contact with the products and were located far from the products. The results showed that the prevalence of Listeria spp. in roasted and steamed products was affected by the prevalence of Listeria contamination in all zones, especially zone 1, which demonstrated the highest correlation. In addition, the prevalence of Listeria contamination in zones 2 and 3 affected the prevalence of Listeria in zone 1. A correlation between Listeria on roasted chicken products and the surfaces of zone 1 at the start of production was also established.

  7. Multiple cortical brain abscesses due to Listeria monocytogenes in an immunocompetent patient.

    Science.gov (United States)

    Khan, Sadia; Kumar, Anil; Kale, Satyajit; Kurkure, Nitin; Nair, Gulsiv; Dinesh, Kavitha

    2018-04-01

    Listeria monocytogenes is an intracellular organism which is well recognised for its ability to cause meningeal infections in neonates, immunosuppressed, debilitated and elderly individuals. 1 Other less common central nervous system (CNS) infections caused by Listeria spp. include rhomboencephalitis, cerebritis and abscesses in the brain, brain stem and spinal cord. The neuroradiological appearance of Listeria brain abscesses is similar to other types and may also mimic primary or metastatic brain tumours. 2 , 3 We report a case of Listeria brain abscesses in a patient who was being treated for atypical parkinsonism. A good clinical outcome was achieved after appropriate antimicrobial therapy.

  8. Listeria monocytogenes - Danger for health safety vegetable production.

    Science.gov (United States)

    Kljujev, Igor; Raicevic, Vera; Jovicic-Petrovic, Jelena; Vujovic, Bojana; Mirkovic, Milica; Rothballer, Michael

    2018-04-22

    The microbiologically contaminated vegetables represent a risk for consumers, especially vegetables without thermal processing. It is known that human pathogen bacteria, such as Listeria monocytogenes, could exist on fresh vegetables. The fresh vegetables could become Listeria-contaminated if they come in touch with contaminated soil, manure, irrigation water. The aim of this work was to investigate the presence of Listeria spp. and L. monocytogenes in different kind of vegetables grown in field and greenhouse condition as well as surface and endophytic colonization plant roots of different vegetables species by L. monocytogenes in laboratory conditions. The detection of Listeria spp. and L. monocytogenes in vegetable samples was done using ISO and PCR methods. The investigation of colonization vegetable roots and detection Listeria-cells inside plant root tissue was done using Fluorescence in situ hybridization (FISH) method in combination with confocal laser scanning microscopy (CLSM). The results showed that 25.58% vegetable samples were positive for Listeria spp. and only one sample (carrot) was positive for L. monocytogenes out of 43 samples in total collected from field and greenhouse. The strain L. monocytogenes EGD-E surface and endophytic colonized carrot root in highest degree while strain L. monocytogenes SV4B was the most represented at leafy vegetable plants, such at lettuce (1.68 × 10 6  cells/mm 3 absolutely dry root) and spinach (1.39 × 10 6  cells/mm 3 absolutely dry root) root surface. The cells of L. monocytogenes SV4B were visible as single cells in interior tissue of plant roots (celery and sweet corn roots) as well as in the interior of the plant root cell at sweet corn root. The cells of L. monocytogenes EGD-E bind to the surface of the plant root and they were less commonly found out on root hair. In the inner layers of the root, those bacterial cells were inhabited intercellular spaces mainly as single cells very close to the

  9. Central nervous system tuberculosis in children: review of 35 cases at the Hospital Universitario San Vicente de Paúl in Medellín, Colombia.1997-2004. Meningoencefalitis tuberculosa en niños: Revisión de 35 casos en el Hospital Universitario San Vicente de Paúl en Medellín, Colombia. 1997-2004

    Directory of Open Access Journals (Sweden)

    José William Cornejo Ochoa

    2005-04-01

    Full Text Available Objetive. To document the clinical and diagnostic features and to explore factors associated with central nervous system tuberculosis at the “Hospital San Vicente de Paúl (HUSVP” in Medellín-Colombia. Patients and methods. Review of the patient’s records to obtain information on demographic data, medical history, clinical manifestations, laboratory results, treatment and complications of 35 children with central nervous system tuberculosis admitted to the hospital between July 1997 and July 2004. Results. Of the 35 patients, 20 were males and 15 females. Mean age was 3.7 years. Thirty (85.7% patients were in stage III of the disease and 5 (14.3% in stage II. A symptomatic respiratory close contact was documented in 19 cases (54.3%. Malnutrition was present in 18 patients (51.4%. Fever was present in 88.6%, vomiting in 62.9%, consciousness alteration in 80%, and seizures in 51.4%. Mean duration of symptoms was 10 days. Physical examination revealed meningeal signs in 77%, movement disorders in 31.4%, stupor or coma in 82.9%, hemiparesis in 60% and fundoscopic abnormalities in 31.4%. Objetivo: documentar los rasgos clínicos y diagnósticos y explorar los factores asociados con la muerte de niños con meningoencefalitis tuberculosa (MT en el Hospital Universitario San Vicente de Paúl, Medellín, Colombia. Método: revisión de las historias clínicas para obtener los datos demográficos, clínicos, de laboratorio, de tratamiento y de las complicaciones de 35 niños con tuberculosis del sistema nervioso central, entre julio de 1997 y julio de 2004. Resultados: veinte de los 35 pacientes eran niños y 15 niñas. La edad promedio era 3.7 años; 30 (85.7% estaban en el estadio III de la enfermedad y 5 (14.3%, en el estadio II. Se documentó un contacto sintomático respiratorio en 19 casos (54.3%. Diez y ocho pacientes (51.4% estaban desnutridos. Hubo fiebre en 88.6%, vómito en 62.9%, alteración de la conciencia en 80% y convulsiones en 51

  10. Efeito da adição de Lactobacillus rhamnosus em queijos Minas frescal sobre as contagens de Staphylococcus aureus e Listeria monocytogenes

    OpenAIRE

    Lígia Eleonor Prezzi

    2014-01-01

    O objetivo deste estudo foi avaliar o efeito inibitório de Lactobacillus rhamnosus sobre as contagens de Staphylococcus aureus e Listeria monocytogenes, aspergidos isoladamente ou em combinação sobre a superfície de queijo Minas Frescal, durante armazenamento por 21 dias a 7ºC. O delineamento consistiu em esquema fatorial 2x2x2, sendo 8 tratamentos com 4 repetições. As características físico-químicas (pH, atividade de água, umidade, teor de gordura, proteína e perfil de textura) foram determi...

  11. A study on the effects of some laboratory-derived genetic mutations on biofilm formation by Listeria monocytogenes

    Digital Repository Service at National Institute of Oceanography (India)

    Kumar, S.; Parvathi, A.; George, J.; Krohne, G.; Karunasagar, Indrani; Karunasagar, Iddya

    , Germany Address for correspondence Sanath Kumar ENMU 2386 1500 S, Ave K Portales, New Mexico 88130 USA e-mail: sanathkm@yahoo.com Running Title: Gene mutations and Listeria biofilm Abstract Biofilms formed by the human pathogen Listeria...

  12. InlB-mediated Listeria monocytogenes internalization requires a balanced phospholipase D activity maintained through phospho-cofilin

    NARCIS (Netherlands)

    Han, Xuelin; Yu, Rentao; Ji, Lei; Zhen, Dongyu; Tao, Sha; Li, Shuai; Sun, Yansong; Huang, Liuyu; Feng, Zhe; Li, Xianping; Han, Gaige; Schmidt, Martina; Han, Li

    Internalization of Listeria monocytogenes into non-phagocytic cells is tightly controlled by host cell actin dynamics and cell membrane alterations. However, knowledge about the impact of phosphatidylcholine cleavage driven by host cell phospholipase D (PLD) on Listeria internalization into

  13. Prevalence of Listeria species in camel sausages from retail markets in Aydin province in Turkey and RAPD analysis of Listeria monocytogenes Isolates

    Directory of Open Access Journals (Sweden)

    Ozbey Gokben

    2006-06-01

    Full Text Available Abstract Samples were taken from 100 camel sausages from the different retail markets in Aydin province in the south-west of Turkey and they were tested for the presence of Listeria spp by biochemical methods. Samples were enriched using Listeria Enrichment Broth and they were inoculated onto Listeria Selective Agar. Listeria monocytogenes was isolated from nine samples (9%, Listeria innocua from 14 samples (14% and Listeria welshimeri from two samples(2%. A 701 bp fragment of listeriolysin O sequence for L. monocytogenes was amplified using specific primers by polymerase chain reaction (PCR for confirmation of the identification. A random primer (OPA-11 was used in a random amplified polymorphic DNA (RAPD assay. This detected five different band profiles amongst the L. monocytogenes isolates, indicating a relatively large amount of genetic heterogeneity amongst the nine isolates. The study has highlighted the need for improved strategies for food safety, in particular appropriate hygienic precautions to avoid contamination of sausage during the manufacturing process and appropriate preservation techniques during storage and transport, to prevent transmission of Listeria spp to consumers at home and abroad.

  14. Detección de Listeria spp. y Listeria monocytogenes en muestras de leche cruda y quesos artesanales respectivamente, mediante PCR en Tiempo Real

    Directory of Open Access Journals (Sweden)

    Viviana Pamela Chiluisa-Utreras

    2017-07-01

    Full Text Available Background. In Ecuador, studies about bacteria genre Listeria in artisanal cheeses are scarce, and in raw milk, practically nonexistent. Milk production is one of the main livestock activities in the province of Pichincha and it is essential to study these products. Since all the cantons that make up Pichincha are milk producers, three of them, Cayambe, Quito and Pedro Moncayo were randomly sampled. Objective. To determine Listeria spp. And Listeria monocytogenes in samples of raw milk and artisanal cheeses, respectively, using Real Time PCR. Methods. The application of the qPCR technique in the detection of microorganisms and especially of bacteria in food, is based on four fundamental aspects: its sensitivity, specificity, speed and processing capacity of large sample flow. It is possible to detect small amounts of pathogenic microorganisms, such as Listeria spp in raw milk, after extraction and quantification of total DNA. Results. In this study in raw milk, one positive was determined from a total of 60 samples, representing 1.6% of Listeria spp. and 16 positive samples of 45, representing 35.6% of Listeria monocytogenes in artisanal cheeses from three farms in the province of Pichincha. Conclusions. The results, according to the statistical analyzes carried out with the Kruskal - Wallis test, show that in Pichincha the bacterium is present in raw milk, but in non - representative quantities, whereas for Listeria monocytogenes there is statistical significance in the cheeses samples

  15. Antimicrobial Resistance Profiles of Listeria monocytogenes and Listeria innocua Isolated from Ready-to-Eat Products of Animal Origin in Spain.

    Science.gov (United States)

    Escolar, Cristina; Gómez, Diego; Del Carmen Rota García, María; Conchello, Pilar; Herrera, Antonio

    2017-06-01

    The objective of this work was to investigate the antimicrobial resistance in Listeria spp. isolated from food of animal origin. A total of 50 Listeria strains isolated from meat and dairy products, consisting of 7 Listeria monocytogenes and 43 Listeria innocua strains, were characterized for antimicrobial susceptibility against nine antimicrobials. The strains were screened by real-time PCR for the presence of antimicrobial resistance genes: tet M, tet L, mef A, msr A, erm A, erm B, lnu A, and lnu B. Multidrug resistance was identified in 27 Listeria strains, 4 belonging to L. monocytogenes. Resistance to clindamycin was the most common resistance phenotype and was identified in 45 Listeria strains; the mechanisms of resistance are still unknown. A medium prevalence of resistance to tetracycline (15 and 9 resistant and intermediate strains) and ciprofloxacin (13 resistant strains) was also found. Tet M was detected in Listeria strains with reduced susceptibility to tetracycline, providing evidence that both L. innocua and L. monocytogenes displayed acquired resistance. The presence of antimicrobial resistance genes in L. innocua and L. monocytogenes indicates that these genes may be transferred to commensal and pathogenic bacteria via the food chain; besides this, antibiotic resistance in L. monocytogenes could compromise the effective treatment of listeriosis in humans.

  16. Magnetic bead based immuno-detection of Listeria monocytogenes and Listeria ivanovii from infant formula and leafy green vegetables using the Bio-Plex suspension array system.

    Science.gov (United States)

    Day, J B; Basavanna, U

    2015-04-01

    Listeriosis, a disease contracted via the consumption of foods contaminated with pathogenic Listeria species, can produce severe symptoms and high mortality in susceptible people and animals. The development of molecular methods and immuno-based techniques for detection of pathogenic Listeria in foods has been challenging due to the presence of assay inhibiting food components. In this study, we utilize a macrophage cell culture system for the isolation and enrichment of Listeria monocytogenes and Listeria ivanovii from infant formula and leafy green vegetables for subsequent identification using the Luminex xMAP technique. Macrophage monolayers were exposed to infant formula, lettuce and celery contaminated with L. monocytogenes or L. ivanovii. Magnetic microspheres conjugated to Listeria specific antibody were used to capture Listeria from infected macrophages and then analyzed using the Bio-Plex 200 analyzer. As few as 10 CFU/mL or g of L. monocytogenes was detected in all foods tested. The detection limit for L. ivanovii was 10 CFU/mL in infant formula and 100 CFU/g in leafy greens. Microsphere bound Listeria obtained from infected macrophage lysates could also be isolated on selective media for subsequent confirmatory identification. This method presumptively identifies L. monocytogenes and L. ivanovii from infant formula, lettuce and celery in less than 28 h with confirmatory identifications completed in less than 48 h. Published by Elsevier Ltd.

  17. Uncovering Listeria monocytogenes hypervirulence by harnessing its biodiversity

    Science.gov (United States)

    Charlier, Caroline; Touchon, Marie; Chenal-Francisque, Viviane; Leclercq, Alexandre; Criscuolo, Alexis; Gaultier, Charlotte; Roussel, Sophie; Brisabois, Anne; Disson, Olivier; Rocha, Eduardo P. C.; Brisse, Sylvain; Lecuit, Marc

    2016-01-01

    Microbial pathogenesis studies are typically performed with reference strains, thereby overlooking microbial intra-species virulence heterogeneity. Here we integrated human epidemiological and clinical data with bacterial population genomics to harness the biodiversity of the model foodborne pathogen Listeria monocytogenes and decipher the basis of its neural and placental tropisms. Taking advantage of the clonal structure of this bacterial species, we identify clones epidemiologically associated with either food or human central nervous system (CNS) and maternal-neonatal (MN) listeriosis. The latter are also most prevalent in patients without immunosuppressive comorbidities. Strikingly, CNS and MN clones are hypervirulent in a humanized mouse model of listeriosis. By integrating epidemiological data and comparative genomics, we uncovered multiple novel putative virulence factors and demonstrated experimentally the contribution of the first gene cluster mediating Listeria monocytogenes neural and placental tropisms. This study illustrates the exceptional power of harnessing microbial biodiversity to identify clinically relevant microbial virulence attributes. PMID:26829754

  18. Growth inhibition of Listeria monocytogenes by a nonbacteriocinogenic Carnobacterium piscicola

    DEFF Research Database (Denmark)

    Nilsson, Lilian; Bech Hansen, T.; Garrido, P.

    2005-01-01

    Aims: This study elucidates the mechanisms by which a nonbacteriocinogenic Carnobacterium piscicola inhibits growth of Listeria monocytogenes. Methods and Results: Listeria monocytogenes was exposed to live cultures of a bacteriocin-negative variant of C. piscicola A9b in co-culture, in a diffusion...... chamber system, and to a cell-free supernatant. Suppression of maximum cell density (0-3.5 log units) of L. monocytogenes was proportional to initial levels of C. pisciola (10(3)-10(7) CFU ml(-1)). Cell-to-cell contact was not required to cause inhibition. The cell-free C. piscicola supernatant caused...... a decrease in L. monocytogenes maximum cell density, which was abolished by glucose addition but not by amino acid, vitamin or mineral addition. The fermentate also gave rise to a longer lag phase and a reduction in growth rate. These effects were independent of glucose and may have been caused by acetate...

  19. Role of Extracellular DNA during Biofilm Formation by Listeria monocytogenes

    DEFF Research Database (Denmark)

    Harmsen, Morten; Lappann, Martin; Knøchel, S

    2010-01-01

    (eDNA) may be the only central component of the biofilm matrix and that it is necessary for both initial attachment and early biofilm formation for 41 L. monocytogenes strains that were tested. DNase I treatment resulted in dispersal of biofilms, not only in microtiter tray assays but also in flow......Listeria monocytogenes is a food-borne pathogen that is capable of living in harsh environments. It is believed to do this by forming biofilms, which are surface-associated multicellular structures encased in a self-produced matrix. In this paper we show that in L. monocytogenes extracellular DNA...... cell biofilm assays. However, it was also demonstrated that in a culture without eDNA, neither Listeria genomic DNA nor salmon sperm DNA by itself could restore the capacity to adhere. A search for additional necessary components revealed that peptidoglycan (PG), specifically N-acetylglucosamine (NAG...

  20. Listeria spp., y L. monocytogenes EN LECHE CRUDA DE CABRA

    Directory of Open Access Journals (Sweden)

    Yolanda Albarracín C

    2008-08-01

    Full Text Available Objective. To test non-pasteurized goat’s milk from the village of ‘la Garita’, Northern Santander, for Listeria monocytogenes. Material and methods. 90 samples of non-pasteurized goat’s milk were obtained over a 4 month period; pH and temperature of each sample were measured. The INVIMA technique was used to isolate L. monocytogenes; the species was confirmed by PCR. Results. The study showed that eight goat milk providers of the zone neither had refrigeration nor pasteurized the milk. The prevalence of L. monocytogenes was 3%; 15% of the samples had other species of Listeria. The milk obtained from this zone contained the pathogen that may cause listeriosis in children less than 5 years of age, pregnant women, adults and immunologically compromised patients. Conclusions. This study shows the occurrence of this pathogen in goat’s milk and identified areas of risk for those people who drink goat’s milk.

  1. Biosensor for the detection of Listeria monocytogenes: emerging trends

    KAUST Repository

    Soni, Dharmendra Kumar

    2018-05-23

    The early detection of Listeria monocytogenes (L. monocytogenes) and understanding the disease burden is of paramount interest. The failure to detect pathogenic bacteria in the food industry may have terrible consequences, and poses deleterious effects on human health. Therefore, integration of methods to detect and trace the route of pathogens along the entire food supply network might facilitate elucidation of the main contamination sources. Recent research interest has been oriented towards the development of rapid and affordable pathogen detection tools/techniques. An innovative and new approach like biosensors has been quite promising in revealing the foodborne pathogens. In spite of the existing knowledge, advanced research is still needed to substantiate the expeditious nature and sensitivity of biosensors for rapid and in situ analysis of foodborne pathogens. This review summarizes recent developments in optical, piezoelectric, cell-based, and electrochemical biosensors for Listeria sp. detection in clinical diagnostics, food analysis, and environmental monitoring, and also lists their drawbacks and advantages.

  2. Evaluation of Immune Responses Mediated by Listeria-Stimulated Human Dendritic Cells: Implications for Cancer Vaccine Therapy

    Science.gov (United States)

    2014-07-01

    include: 1) Listeria infection, including that mediated by attenuated strains, induces moDC, DDC , and LC maturation and activation. 2) Listeria...2f) Flow cytometry analysis of DCs for co-stimulatory and maturation markers (months 3-12) Result/status: Listeria-treated DDC -IDCs and LCs were...for moDCs, infection of DDC -IDCs and LCs with wild-type, LLO-deficient, and ActA- deficient Listeria induces the activation and maturation of DDC

  3. Effect of eugenol on growth and listeriolysin o production by Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    Cristina Tostes Filgueiras

    2006-05-01

    Full Text Available The inhibitory effect of eugenol, a naturally occurring compound mainly present in the essential oil fraction of cloves, was studied on the growth and listeriolysin O (LLO production by Listeria monocytogenes. Potassium efflux from cells promoted by eugenol was also determined after 24 h incubation in phosphate buffered saline. Eugenol promoted a delay on the growth of L. monocytogenes at concentrations of 100, 300 and 500 µg mL-1and above 800 µg mL-1 the effect was bactericidal. Production of LLO by L. monocytogenes in the presence of eugenol was reduced 80-100%. An accumulation of external K+ was observed above 300 µg mL-1 of eugenol which indicated that the cell membrane was affected. The results showed the effectiveness of eugenol in controlling growth and LLO production of L. monocytogenes cells.O efeito inibitório do eugenol, o principal constituinte do óleo essencial de cravo, foi avaliado sobre o crescimento e produção de listeriolisina O (LLO por Listeria monocytogenes. O efluxo de íons potássio das células também foi determinado após 24 h de incubação em solução tampão, contendo eugenol. Concentrações de 100, 300 e 500 µg mL-1 de eugenol promoveram a inibição do crescimento de L. monocytogenes e, em concentrações acima de 800 µg mL-1, constatou-se um efeito bactericida. O crescimento de L. monocytogenes na presença de eugenol resultou na inibição de 80 a 100% da produção de LLO. O efluxo de K+ promovido pelo eugenol indicou que a membrana celular foi afetada. Estes resultados indicam a efetividade do eugenol para o controle do crescimento e da produção de LLO por L. monocytogenes.

  4. CHALLENGE TESTS WITH LISTERIA MONOCYTOGENES IN SALAMI: PRELIMINARY RESULTS

    Directory of Open Access Journals (Sweden)

    R. Mioni

    2013-02-01

    Full Text Available Challenge tests are the preferable methodology to study the behaviour of Listeria monocytogenes on ready to eat foods, according to Regulation (EC 2073/2005. Challenge testing using L. monocytogenes in seasoned salami from different food business operators showed, after seasoning of the product, a count reduction of the inoculated organisms without any further growth of the pathogen; however differences of L. monocytogenes behaviour could be observed according to different production protocols.

  5. Disinfectant effect of Methylated Ethanol against Listeria species

    OpenAIRE

    Y Yakubu; M D Salihu; O O Faleke; M B Abubakar; A A Magaji,A U Junaidu

    2012-01-01

    This study was carried out in order to determine the disinfectant effect of Methylated spirit® (95% methanol and 5% ethanol) as a teat dip against Listeria species. Hand milking was employed to collect 576 (288 x 2) raw milk samples from different lactating cows within Sokoto metropolis (Nigeria). 288 samples were collected before disinfecting the udder teats with Methylated spirit®, while the other 288 were collected after disinfection with Methylated spirit®. The ...

  6. CELLULAR VACCINES IN LISTERIOSIS: ROLE OF THE LISTERIA ANTIGEN GAPDH.

    Directory of Open Access Journals (Sweden)

    Ricardo eCalderon-Gonzalez

    2014-02-01

    Full Text Available The use of live Listeria-based vaccines carries serious difficulties when administrated to immunocompromised individuals. However, cellular carriers have the advantage of inducing multivalent innate immunity as well as cell-mediated immune responses, constituting novel and secure vaccine strategies in listeriosis. Here, we compare the protective efficacy of dendritic cells (DCs and macrophages and their safety. We examined the immune response of these vaccine vectors using two Listeria antigens, listeriolysin O (LLO and glyceraldehyde-3-phosphate-dehydrogenase (GAPDH, and several epitopes such as the LLO peptides, LLO189–201 and LLO91–99 and the GAPDH peptide, GAPDH1–22. We discarded macrophages as safe vaccine vectors because they show anti-Listeria protection but also high cytotoxicity. DCs loaded with GAPDH1–22 peptide conferred higher protection and security against listeriosis than the widely explored LLO91–99 peptide. Anti-Listeria protection was related to the changes in DC maturation caused by these epitopes, with high production of interleukin-12 as well as significant levels of other Th1 cytokines such as monocyte chemotactic protein-1, tumor necrosis factor-α, and interferon-γ, and with the induction of GAPDH1–22-specific CD4+ and CD8+ immune responses. This is believed to be the first study to explore the use of a novel GAPDH antigen as a potential DC-based vaccine candidate for listeriosis, whose efficiency appears to highlight the relevance of vaccine designs containing multiple CD4+ and CD8+ epitopes.

  7. Cellular vaccines in listeriosis: role of the Listeria antigen GAPDH

    Science.gov (United States)

    Calderón-González, Ricardo; Frande-Cabanes, Elisabet; Bronchalo-Vicente, Lucía; Lecea-Cuello, M. Jesús; Pareja, Eduardo; Bosch-Martínez, Alexandre; Fanarraga, Mónica L.; Yañez-Díaz, Sonsoles; Carrasco-Marín, Eugenio; Álvarez-Domínguez, Carmen

    2014-01-01

    The use of live Listeria-based vaccines carries serious difficulties when administrated to immunocompromised individuals. However, cellular carriers have the advantage of inducing multivalent innate immunity as well as cell-mediated immune responses, constituting novel and secure vaccine strategies in listeriosis. Here, we compare the protective efficacy of dendritic cells (DCs) and macrophages and their safety. We examined the immune response of these vaccine vectors using two Listeria antigens, listeriolysin O (LLO) and glyceraldehyde-3-phosphate-dehydrogenase (GAPDH), and several epitopes such as the LLO peptides, LLO189−201 and LLO91−99 and the GAPDH peptide, GAPDH1−22. We discarded macrophages as safe vaccine vectors because they show anti-Listeria protection but also high cytotoxicity. DCs loaded with GAPDH1−22 peptide conferred higher protection and security against listeriosis than the widely explored LLO91−99 peptide. Anti-Listeria protection was related to the changes in DC maturation caused by these epitopes, with high production of interleukin-12 as well as significant levels of other Th1 cytokines such as monocyte chemotactic protein-1, tumor necrosis factor-α, and interferon-γ, and with the induction of GAPDH1−22-specific CD4+ and CD8+ immune responses. This is believed to be the first study to explore the use of a novel GAPDH antigen as a potential DC-based vaccine candidate for listeriosis, whose efficiency appears to highlight the relevance of vaccine designs containing multiple CD4+ and CD8+ epitopes. PMID:24600592

  8. Prevalence and antimicrobial resistance of listeria species isolated from different types of raw meat in Iran.

    Science.gov (United States)

    Rahimi, Ebrahim; Yazdi, Farzad; Farzinezhadizadeh, Hussein

    2012-12-01

    Listeria and particularly Listeria monocytogenes are important foodborne pathogens that can cause listeriosis and severe complications in immunocompromised individuals, children, pregnant women, and the elderly. The objective of this study was to determine the prevalence of Listeria spp. in raw meat in Iran. From July 2010 to November 2011, a total of 1,107 samples of various raw meats were obtained from randomly selected retail butcher shops. The results of conventional bacteriologic and PCR methods revealed that 141 samples (12.7%) were positive for Listeria spp. The highest prevalence of Listeria was found in raw buffalo meat samples (7 of 24 samples; 29.2%) followed by quail meat (26 of 116 samples; 22.4%), partridge meat (13 of 74 samples; 17.6%), and chicken meat (27 of 160 samples; 16.9%). The most common species recovered was Listeria innocua (98 of 141 strains; 75.9 % ); the remaining isolates were L. monocytogenes (19.1% of strains), Listeria welshimeri (6.4% of strains), Listeria seeligeri (3.5% of strains), and Listeria grayi (1.4% of strains). Susceptibilities of the 141 strains to 11 antimicrobial drugs were determined using the disk diffusion assay. Overall, 104 (73.8%) of the Listeria isolates were resistant to one or more antimicrobials, and 17.0% of the isolates were resistant to three or more antimicrobials. The present study provides the first baseline data on the prevalence of Listeria in raw meat derived from sheep, goat, buffalo, quail, partridge, chicken, and ostrich in Iran and the susceptibility of these isolates to antimicrobials.

  9. Behaviour of Listeria monocytogenes in packaged fresh mushrooms (Agaricus bisporus).

    Science.gov (United States)

    González-Fandos, E; Olarte, C; Giménez, M; Sanz, S; Simón, A

    2001-11-01

    The aim of this study was to evaluate the potential of Listeria monocytogenes to grow in mushrooms packaged in two different types of PVC films when stored at 4 degrees C and 10 degrees C. Mushrooms were packed in two polymeric films (perforated and nonperforated PVC) and stored at 4 degrees C and 10 degrees C. The carbon dioxide and oxygen content inside the packages, aerobic mesophiles, psychrotrophs, Pseudomonas spp., Listeria monocytogenes, faecal coliforms, Escherichia coli, anaerobic spores and major sensory factors were determined. The mushrooms packaged in nonperforated film and stored at 4 degrees C had the most desirable quality parameters (texture, development stage and absence of moulds). Listeria monocytogenes was able to grow at 4 degrees C and 10 degrees C in inoculated mushrooms packaged in perforated and nonperforated films between 1 and 2 log units during the first 48 h. After 10 d of storage, the populations of L. monocytogenes were higher in mushrooms packaged in nonperforated film and stored at 10 degrees C. MAP followed by storage at 4 degrees C or 10 degrees C extends the shelf life by maintaining an acceptable appearance, but allows the growth and survival of L. monocytogenes. According to this study additional hurdles must be studied in order to prevent the growth of L. monocytogenes.

  10. Efficacy of a variety of disinfectants against Listeria spp.

    Science.gov (United States)

    Best, M; Kennedy, M E; Coates, F

    1990-02-01

    The efficacy of 14 disinfectants against Listeria innocua and two strains of Listeria monocytogenes in the presence of organic matter was studied. Quantitative efficacy tests were used. Many of the disinfectants tested were not as effective on Listeria spp. when the test organisms were dried onto the surface of steel disks (carrier tests) as they were when the organisms were placed in suspension (suspension test). The presence of whole serum and milk (2% fat) further reduced the disinfectant capacities of most of the formulations studied. Only three disinfectants (povidone-iodine, chlorhexidine gluconate, and glutaraldehyde) were effective in the carrier test in the presence of serum; however, all three were ineffective when challenged with milk (2% fat). Only one solution, sodium dichloroisocyanurate, was effective in the presence of milk. All but four formulations (chloramine-T, phosphoric acid, an iodophor, and formaldehyde) were effective in the suspension tests, regardless of the organic load. L. monocytogenes was observed to be slightly more resistant to disinfection than L. innocua was. There was no difference in disinfectant susceptibility between the two strains of L. monocytogenes. These findings emphasize the need for caution in selecting an appropriate disinfectant for use on contaminated surfaces, particularly in the presence of organic material.

  11. Identification of Listeria monocytogenes on Green Mussels and Cockle Shell

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    Winiati Puji Rahayu

    2017-02-01

    Full Text Available AbstractGreen mussel (Perna viridis and cockle shell (Anadara granosa are one of many sources of animal protein which is many cultivated in Indonesia because their price is relatively affordable. This study was conducted to identify the presence of Listeria monocytogenes in 27 samples of green mussels and 3 samples of cockle shells using real-time Polymerase Chain Reaction (real-time PCR and biochemical methods. The target gene for amplification in real-time PCR was an hlyA gene because this gene was a determinant of virulence genes that produce listeriolysin O. Primers used in this study were forward primer DG69 (GTG CCG GGT AAA AGA CCA TA and reverse primer DG74 (CGC CAC TGA GAT ACT AT and fluorescence signals indicator using SYBR Green I. The results of analysis using real-time PCR were negative Listeria monocytogenes in all samples, while using biochemical methods there was one of 30 samples contaminated by Listeria welshimeri.

  12. Commensal microbes provide first line defense against Listeria monocytogenes infection

    Science.gov (United States)

    Littmann, Eric R.; Kim, Sohn G.; Morjaria, Sejal M.; Ling, Lilan; Gyaltshen, Yangtsho; Taur, Ying; Leiner, Ingrid M.

    2017-01-01

    Listeria monocytogenes is a foodborne pathogen that causes septicemia, meningitis and chorioamnionitis and is associated with high mortality. Immunocompetent humans and animals, however, can tolerate high doses of L. monocytogenes without developing systemic disease. The intestinal microbiota provides colonization resistance against many orally acquired pathogens, and antibiotic-mediated depletion of the microbiota reduces host resistance to infection. Here we show that a diverse microbiota markedly reduces Listeria monocytogenes colonization of the gut lumen and prevents systemic dissemination. Antibiotic administration to mice before low dose oral inoculation increases L. monocytogenes growth in the intestine. In immunodeficient or chemotherapy-treated mice, the intestinal microbiota provides nonredundant defense against lethal, disseminated infection. We have assembled a consortium of commensal bacteria belonging to the Clostridiales order, which exerts in vitro antilisterial activity and confers in vivo resistance upon transfer into germ free mice. Thus, we demonstrate a defensive role of the gut microbiota against Listeria monocytogenes infection and identify intestinal commensal species that, by enhancing resistance against this pathogen, represent potential probiotics. PMID:28588016

  13. Incidence of Listeria species in bovine, ovine, caprine, camel and water buffalo milk using cultural method and the PCR assay

    Directory of Open Access Journals (Sweden)

    Ebrahim Rahimi

    2014-02-01

    Full Text Available Objective: To determine the prevalence rate of Listeria species in bovine, ovine, caprine, camel and water buffalo milk in Iran. Methods: From September 2010 to December 2011 a total of 260 bulk milk samples including 85 bovine, 37 camel, 34 water buffalo, 56 ovine and 48 caprine bulk milk samples were collected from commercial dairy herds, in Fars and Khuzestan provinces, Iran and were evaluated for the presence of Listeria species using cultural method and the PCR assay. Results: Using cultural method, 19 samples (7.3% were positive for Listeria spp. The highest prevalence of Listeria was found in raw water buffalo milk (11.8%, followed by raw bovine milk (10.6%, raw ovine milk (7.1%, and raw caprine milk (4.2% samples. All 37 camel milk samples from 20 camel breeding farms were negative for Listeria spp. The overall prevalence of Listeria was 7.3%, in which Listeria innocua was the most recovered species (4.2%; the remaining isolates were Listeria monocytogenes (1.9%, Listeria ivanovii (0.08% and Listeria seeligari (0.04%. The PCR assay could identify 8 Listeria-contaminated milk samples that were negative using the cultural method. Conclusions: The results presented in this study indicate the potential risk of infection with Listeria in people consuming raw and unpasteurized milk.

  14. Effect of Filling Type and Heating Method on Prevalence of Listeria species and Listeria monocytogenes in Dumplings Produced in Poland.

    Science.gov (United States)

    Szymczak, Barbara; Dąbrowski, Waldemar

    2015-05-01

    The count of Listeria monocytogenes was determined, before and after heat treatment, in 200 samples of dumplings of 9 brands and with different types of stuffing. Analyses were conducted according to ISO 11290-1 standard and with real-time PCR method. The highest count of L. monocytogenes was found in meat dumplings (10(2) to 10(4) CFU/g), whereas products with white cheese-potato stuffing and vegetable-mushroom stuffing contained significantly less Listeria, 20 to 80 and 5 to 32 CFU/g, respectively. In cooled meat dumplings the extent of contamination depended significantly on the producer. In addition, a significant (P monocytogenes in meat dumplings. In contrast, the microwave heating applied for 2 min at 600 W only reduced the count of L. monocytogenes by 1 to 2 logs. Hence, the microwave heating failed to reduce the risk of infection with this pathogen below the level permissible in the EU regulation, especially in the most contaminated samples. In this case, the efficacy of microwave heating was significantly (P monocytogenes (rho = 0.626), then by meat content in the stuffing (0.476), and to the lowest extent--by the type of meat (0.415 to 0.425). However, no Listeria sp. and L. monocytogenes were isolated from cooked dumplings with fruits (strawberries or blueberries). © 2015 Institute of Food Technologists®

  15. Higiene alimentaria para la prevención de trastornos digestivos infecciosos y por toxinas

    Directory of Open Access Journals (Sweden)

    G. Manuel Moreno, Dr.

    2010-09-01

    Full Text Available El principal factor que interviene en el origen y prevención de las enfermedades trasmitidas por los alimentos es la higiene alimentaria. Dichas enfermedades son causadas por la ingestión de alimentos o agua contaminados con microorganismos patógenos ocasionando una infección o por la ingestión de alimentos contaminados con toxinas. Los principales agentes involucrados son Escherichia Coli, Campylobacter, Salmonella, Shigella, Listeria Monocytogenes, Norovirus, virus Hepatitis A, Astrovirus, Rotavirus, y Virus Coxsackie. Toxinas producidas por hongos o por microflora marina y los contaminantes orgánicos persistentes pueden también causar serios problemas de salud. La inocuidad alimentaría ha tomado relevancia debido a una mayor exigencia por consumidores cada día más informados y por las demandas del comercio exterior. Medidas que aseguren una adecuada higiene alimentaría nos permitirá prevenir enfermedades, principalmente digestivas, causadas por variados agentes en los alimentos. Esto se logra por la implementación de las medidas propuestas por la Comisión Internacional conocida como Codex Alimentarius.

  16. PASTEURISASI HIGH TEMPERATURE SHORT TIME (HTST) SUSU TERHADAP Listeria monocytogenes PADA PENYIMPANAN REFRIGERATOR

    OpenAIRE

    SABIL, SYAHRIANA

    2015-01-01

    2015 SYAHRIANA SABIL (I 111 11 273). Pasteurisasi High Temperature Short Time (HTST) Susu terhadap Listeria monocytogenes pada Penyimpanan Refrigerator. Dibimbing oleh RATMAWATI MALAKA dan FARIDA NUR YULIATI. Pasteurisasi High Temperature Short Time (HTST) merupakan proses pemanasan susu di bawah titik didih yang diharapkan dapat membunuh Listeria monocytogenes (L. monocytogenes) karena bersifat patogen dan mengakibatkan listeriosis yang merupakan penyakit zoonosis. Tu...

  17. Environmental prevalence and persistence of Listeria monocytogenes in cold-smoked trout processing plants

    Science.gov (United States)

    The presence of Listeria monocytogenes on the surfaces of equipment and workers' hands during different production stages, as well as on fish skin and meat during processing and storage of cold-smoked trout, was investigated. Listeria monocytogenes was recovered from 10 (6.06%) of a total 165 cotto...

  18. Genome Sequences of Two Listeria monocytogenes Strains from Nectarines Associated with Listeriosis in 2014

    Science.gov (United States)

    Lu, Chunye; Marjanovic, Olivera; Kiang, David

    2017-01-01

    ABSTRACT Listeria monocytogenes is an important foodborne pathogen. Here, we present the annotated whole genome of Listeria monocytogenes strains F14M01297-C2 and F14M01297-C4, isolated from nectarines distributed by a packing facility in California during an investigation of listeriosis associated with stone fruit in 2014. PMID:28729255

  19. A multiplex PCR for detection of Listeria monocytogenes and its lineages.

    Science.gov (United States)

    Rawool, Deepak B; Doijad, Swapnil P; Poharkar, Krupali V; Negi, Mamta; Kale, Satyajit B; Malik, S V S; Kurkure, Nitin V; Chakraborty, Trinad; Barbuddhe, Sukhadeo B

    2016-11-01

    A novel multiplex PCR assay was developed to identify genus Listeria, and discriminate Listeria monocytogenes and its major lineages (LI, LII, LIII). This assay is a rapid and inexpensive subtyping method for screening and characterization of L. monocytogenes. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Listeria monocytogenes meningitis: serotype distribution and patient characteristics in The Netherlands, 1976-95

    NARCIS (Netherlands)

    Aouaj, Y.; Spanjaard, L.; van Leeuwen, N.; Dankert, J.

    2002-01-01

    Two hundred and seven cases of listeria meningitis that occurred in The Netherlands over 20 years were reviewed to study associations between Listeria monocytogenes serotype, age, underlying disease, and outcome. The mean annual incidence per 100000 population was 0.12 in 1981-90, decreasing to 0.07

  1. Small molecules targeting LapB protein prevent Listeria attachment to catfish muscle.

    Directory of Open Access Journals (Sweden)

    Ali Akgul

    Full Text Available Listeria monocytogenes is a Gram-positive foodborne pathogen and the causative agent of listeriosis. L. monocytogenes lapB gene encodes a cell wall surface anchor protein, and mutation of this gene causes Listeria attenuation in mice. In this work, the potential role of Listeria LapB protein in catfish fillet attachment was investigated. To achieve this, boron-based small molecules designed to interfere with the active site of the L. monocytogenes LapB protein were developed, and their ability to prevent L. monocytogenes attachment to fish fillet was tested. Results indicated that seven out of nine different small molecules were effective in reducing the Listeria attachment to catfish fillets. Of these, three small molecules (SM3, SM5, and SM7 were highly effective in blocking Listeria attachment to catfish fillets. This study suggests an alternative strategy for reduction of L. monocytogenes contamination in fresh and frozen fish products.

  2. PRÉVALENCE DE LISTERIA MONOCYTOGENES DANS LE LAIT CRU DE VACHE AU LIBAN NORD

    Directory of Open Access Journals (Sweden)

    Imad al Kassaa

    2016-06-01

    Full Text Available Al Kassaa Imad, Khaled el Omari, Marwa Saati, Bachar Ismail and Monzer Hamze. 2016. Prevalence of Listeria monocytogenes in raw cow milk in north Lebanon. Lebanese Science Journal, 17(1: 39-45. Listeriosis, although a zoonosis, is an invasive disease that can affect newborns, pregnant women and immunocompromised adults. Clinical manifestations can be expressed by febrile gastroenteritis, invasive forms including severe sepsis, meningitis, rhombencephalitis, prenatal infections and abortions. Species of Listeria bacteria are ubiquitous and adaptable to the environment in animal and plant foods. This study aimed to determine the prevalence of Listeria monocytogenes in 100 samples of fresh cow milk collected from different areas of North Lebanon. Listeria monocytogenes was detected by using the Grand VIDAS technique (Biomérieux France. The results obtained revealed the absence of Listeria monocytogenes in all analyzed samples.

  3. Listeria monocytogenes following orthotopic liver transplantation: Central nervous system involvement and review of the literature

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Listeria monocytogene is a well-recognized cause of bacteremia in immunocompromised individuals, including solid organ transplant recipients, but has been rarely reported following orthotopic liver transplantation. We describe a case of listeria meningitis that occurred within a week after liver transplantation. The patient developed a severe headache that mimicked tacrolimus encephalopathy, and was subsequently diagnosed with listeria meningitis by cerebrospinal fluid culture. The infection was successfully treated with three-week course of intravenous ampicillin. Recurrent hepatitis C followed and was successfully treated with interferon alfa and ribavirin. Fourteen cases of listeriosis after orthotopic liver transplantation have been reported in the English literature. Most reported cases were successfully treated with intravenous ampicillin. There were four cases of listeria meningitis, and the mortality of them was 50%.Early detection and treatment of listeria meningitis are the key to obtaining a better prognosis.

  4. Long-term mortality in patients diagnosed with Listeria monocytogenes meningitis: A Danish nationwide cohort study

    DEFF Research Database (Denmark)

    Roed, Casper; Engsig, Frederik Neess; Omland, Lars Haukali

    2012-01-01

    OBJECTIVES: To determine the long-term mortality, the causes of death and the incidence of cancer in listeria meningitis patients. METHODS: Nationwide, population-based cohort study including all adult patients diagnosed with listeria meningitis from 1977 to 2006 and alive 1 year after diagnosis......, and an age-and gender-matched, population control cohort. Kaplan-Meier tables, Cox regression analysis and cumulative incidence function were used as outcome analyses. RESULTS: We identified 114 listeria meningitis patients and 1026 population controls. The adjusted mortality rate ratio (MRR) for listeria...... meningitis patients the first 5 years of follow-up was 2.35(95% confidence interval (CI) 1.60-3.45) thereafter the MRR was 0.93(95% CI: 0.56-1.55). Listeria meningitis patients had an increased risk of death due to cancer the first 5 years of follow-up, and in the same period patients above 50 years of age...

  5. The Antibiofilm Effect of Ginkgo biloba Extract Against Salmonella and Listeria Isolates from Poultry.

    Science.gov (United States)

    Wu, Yan; Park, Keun Cheol; Choi, Beom Geun; Park, Jin Hwa; Yoon, Ki Sun

    2016-05-01

    Salmonella spp. and Listeria spp. are common foodborne pathogens in poultry and have caused a large number of outbreaks worldwide. Biofilm formation is common in the food industry and is also a mechanism of antimicrobial resistance. The aim of this work was to investigate the antimicrobial effect and mechanism of Ginkgo biloba extract against the biofilm formation of Salmonella and Listeria isolates from poultry at retail markets. Bacteria detection, isolation, and enumeration were carried out on 27 chicken and 29 ducks at retail markets. The effects of temperature and G. biloba extract against biofilm formation of Salmonella and Listeria isolates were measured using the crystal violet assay and swimming and swarming motilities. The monitoring results of Salmonella and Listeria in 56 poultry carcasses at retail markets in Korea showed that the prevalence of Salmonella spp. in poultry was low (5.4%), but the prevalence of Listeria spp (78.6%) was high. L. innocua was the predominant serotype (80%) in the isolated Listeria species. Temperature, strain, and surface affected the biofilm formation of Salmonella spp. and Listeria spp. L. innocua showed the best biofilm formation ability on a 96-well plate, while Salmonella Enteritidis formed the most biofilm on a glass slide. Biofilm formation abilities of Salmonella spp. and Listeria spp. were increased with the increase of temperature. G. biloba extract at 75 μg/mL significantly inhibited biofilm formation of Salmonella spp. and Listeria spp (p Listeria, but not L. monocytogenes. The findings of this study provided the basis for the application of G. biloba extract as a food additive to promote the quality and safety of poultry products.

  6. Impact of Listeria Inoculation and Aerated Steam Sanitization on Volatile Emissions of Whole Fresh Cantaloupes.

    Science.gov (United States)

    Forney, Charles F; Fan, Lihua; Bezanson, Gregory S; Ells, Timothy C; LeBlanc, Denyse I; Fillmore, Sherry

    2018-04-01

    Rapid methods to detect bacterial pathogens on food and strategies to control them are needed to mitigate consumer risk. This study assessed volatile emissions from whole cantaloupe melons (Cucumis melo) as an indicator of Listeria contamination and in response to steam vapor decontamination. Cantaloupe were inoculated with Listeria innocua, a nonpathogenic surrogate for L. monocytogenes, then exposed to 85 °C steam for 240 s (4 min) followed by rapid chilling and storage for 0, 7, 10, or 14 days at 4, 7, or 10 °C. Volatile emissions from whole melons were collected on Carbopack B/Carboxen 1000 headspace collection tubes and analyzed by gas chromatography-mass spectroscopy following thermal desorption. Introduction of L. innocua to cantaloupe rind resulted in a reduction of aromatic compound emission. However, this response was not unique to Listeria contamination in that steam vapor treatment also reduced emission of these compounds. As well, steam vapor treatment diminished the number of viable Listeria and indigenous microflora while causing physiological injury to melon rind. Heat treatment had no significant effects on flesh firmness, color, titratable acidity, or soluble solids, but the production of typical aroma volatiles during postharvest ripening was inhibited. No unique volatile compounds were detected in Listeria contaminated melons. While changes in volatile emissions were associated with Listeria inoculation, they could not be differentiated from heat treatment effects. Results indicate that volatile emissions cannot be used as a diagnostic tool to identify Listeria contamination in whole cantaloupe melons. The detection of pathogen contamination on fresh produce is a continuing challenge. Using a nondestructive screening method, the presence of surrogate Listeria innocua on fresh whole cantaloupes was shown to alter the emissions of aromatic volatiles from whole cantaloupes. However, these altered emissions were not found to be unique to Listeria

  7. Molecular ecology of Listeria monocytogenes and other Listeria species in small and very small ready-to-eat meat processing plants.

    Science.gov (United States)

    Williams, Shanna K; Roof, Sherry; Boyle, Elizabeth A; Burson, Dennis; Thippareddi, Harshavardhan; Geornaras, Ifigenia; Sofos, John N; Wiedmann, Martin; Nightingale, Kendra

    2011-01-01

    A longitudinal study was conducted to track Listeria contamination patterns in ready-to-eat meats from six small or very small meat processing plants located in three states over 1 year. A total of 688 environmental sponge samples were collected from nonfood contact surfaces during bimonthly visits to each plant. Overall, L. monocytogenes was isolated from 42 (6.1%) environmental samples, and its prevalence ranged from 1.7 to 10.8% across different plants. Listeria spp., other than L. monocytogenes, were isolated from 9.5% of samples overall, with the prevalence ranging from 1.5 to 18.3% across different plants. The prevalence of L. monocytogenes correlated well with that of other Listeria spp. for some but not all plants. One L. monocytogenes isolate representing each positive sample was characterized by molecular serotyping, EcoRI ribotyping, and pulsed-field gel electrophoresis typing. Seven sample sites tested positive for L. monocytogenes on more than one occasion, and the same ribotype was detected more than once at five of these sites. Partial sigB sequencing was used to speciate other Listeria spp. isolates and assign an allelic type to each isolate. Other Listeria spp. were isolated more than once from 14 sample sites, and the same sigB allelic type was recovered at least twice from seven of these sites. One plant was colonized by an atypical hemolytic L. innocua strain. Our findings indicate that small and very small meat processing plants that produce ready-to-eat meat products are characterized by a varied prevalence of Listeria, inconsistent correlation between contamination by L. monocytogenes and other Listeria spp., and a unique Listeria molecular ecology.

  8. Antimicrobial activity of chitosan coatings and films against Listeria monocytogenes on black radish.

    Science.gov (United States)

    Jovanović, Gordana D; Klaus, Anita S; Nikšić, Miomir P

    2016-01-01

    The antibacterial activity of chitosan coatings prepared with acetic or lactic acid, as well as of composite chitosan-gelatin films prepared with essential oils, was evaluated in fresh shredded black radish samples inoculated with Listeria monocytogenes ATCC 19115 and L. monocytogenes ATCC 19112 during seven days of storage at 4°C. The chitosan coating prepared with acetic acid showed the most effective antibacterial activity. All tested formulations of chitosan films exhibited strong antimicrobial activity on the growth of L. monocytogenes on black radish, although a higher inhibition of pathogens was achieved at higher concentrations of chitosan. The antimicrobial effect of chitosan films was even more pronounced with the addition of essential oils. Chitosan-gelatin films with thyme essential oils showed the most effective antimicrobial activity. A reduction of 2.4log10CFU/g for L. monocytogenes ATCC 19115 and 2.1log10CFU/g for L. monocytogenes ATCC 19112 was achieved in the presence of 1% chitosan film containing 0.2% of thyme essential oil after 24h of storage. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Study on contamination of sheep meat in Shahrekord area with Listeria ivanovii and determination its antibiotic resistance pattern

    Directory of Open Access Journals (Sweden)

    Farid Khalili Borujeni

    2013-06-01

    Full Text Available Background and objectives: Listeria monocytogenes and Listeria ivanovii are two pathogenic species of Listeria. The role of Listeria ivanovii is important in abortion, stillbirth, septicemia in animals and this bacterium sometimes is pathogenic in humans. Contamination of ovine carcasses during the slaughter and processing can cause foodborne infections in humans. In this study we examined the contamination of sheep meat in slaughter house of Shahrekord city to Listeria ivanovii and determined its antibiotic resistance pattern.Material and Methods: A total 200 samples of sheep meat were collected from abattoir and processed by use of two enrichment method. After doing specific biochemical tests and PCR, Listeria spp was identified and antibiotic resistance of isolated Listeria were tested by the agar disc diffusion method. Results: The contamination of sheep carcasses with listeria was 2.5% (5 out of 200 samples. All five isolates (2.5% were recognized as Listeria ivanovii and were resistant to four antibiotics, sensitive to six antibiotics and intermediate to other antibiotics.  Conclusion: According to the contamination rate in sheep carcasses with Listeria ivanovii and the relatively high antibiotic resistance specified in this bacteria, the role of red meat in transmission of Listeria spp. and appropriate use of antibiotics against this bacteria should be considered.

  10. Matrix-assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) Can Precisely Discriminate the Lineages of Listeria monocytogenes and Species of Listeria.

    Science.gov (United States)

    Ojima-Kato, Teruyo; Yamamoto, Naomi; Takahashi, Hajime; Tamura, Hiroto

    2016-01-01

    The genetic lineages of Listeria monocytogenes and other species of the genus Listeria are correlated with pathogenesis in humans. Although matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has become a prevailing tool for rapid and reliable microbial identification, the precise discrimination of Listeria species and lineages remains a crucial issue in clinical settings and for food safety. In this study, we constructed an accurate and reliable MS database to discriminate the lineages of L. monocytogenes and the species of Listeria (L. monocytogenes, L. innocua, L. welshimeri, L. seeligeri, L. ivanovii, L. grayi, and L. rocourtiae) based on the S10-spc-alpha operon gene encoded ribosomal protein mass spectrum (S10-GERMS) proteotyping method, which relies on both genetic information (genomics) and observed MS peaks in MALDI-TOF MS (proteomics). The specific set of eight biomarkers (ribosomal proteins L24, L6, L18, L15, S11, S9, L31 type B, and S16) yielded characteristic MS patterns for the lineages of L. monocytogenes and the different species of Listeria, and led to the construction of a MS database that was successful in discriminating between these organisms in MALDI-TOF MS fingerprinting analysis followed by advanced proteotyping software Strain Solution analysis. We also confirmed the constructed database on the proteotyping software Strain Solution by using 23 Listeria strains collected from natural sources.

  11. Listeria monocytogenes HAZARD MANAGEMENT IN A TYPICAL PRODUCT: THE CIAUSCOLO

    Directory of Open Access Journals (Sweden)

    S Fisichella

    2013-02-01

    Full Text Available The aim of the present study is to investigate operative procedures that allow to minimize Listeria monocytogenes (L. m. hazard in the main traditional sausage of the internal areas of Marche (Italy: the Ciauscolo, that has received the quality trademark PGI. It is made from lean cuts of well mature pork that is finely minced, adding fat which give the salami his characteristic softness and flavour. It is characterized by having a very little maturing period that determine high aw levels and, for this peculiarity, it allows L. m development.

  12. Carbon dioxide and nisin act synergistically on Listeria monocytogenes

    DEFF Research Database (Denmark)

    Nilsson, Lilian; Chen, Y.H.; Chikindas, M.L.

    2000-01-01

    This paper examines the synergistic action of carbon dioxide and nisin on Listeria monocytogenes Scott A wild-type and nisin-resistant (Nis(r)) cells grown in broth at 4 degrees C. Carbon dioxide extended the lag phase and decreased the specific growth rate of both strains, but to a greater degree...... for cultures in CO2. This synergism between nisin and CO2 was examined mechanistically by following the leakage of carboxyfluorescein (CF) from listerial liposomes. Carbon dioxide enhanced nisin-induced CF leakage, indicating that the synergistic action of CO2 and nisin occurs at the cytoplasmic membrane...

  13. Prevalence and growth of Listeria monocytogenes in naturally contaminated seafood

    DEFF Research Database (Denmark)

    Jørgensen, Lasse Vigel; Huss, Hans Henrik

    1998-01-01

    Listeria monocytogenes contamination of seafood varies with product category. The highest prevalence was found in cold- smoked fish (34-60%), while the lowest was found in heat- treated and cured seafood (4-12%). The prevalence of L. monocytogenes differed greatly in cold-smoked salmon between...... production sites, ranging from monocytogenes. The organism showed moderate growth...... in naturally contaminated cold-smoked, and 'gravad', fish while the growth appeared faster in hot smoked fish. Thus L. monocytogenes is not under control in these products. Finally, the prevalence and growth of L. monocytogenes in naturally contaminated cold-smoked salmon are discussed in relation...

  14. Variations in virulence between different electrophoretic types of Listeria monocytogenes

    DEFF Research Database (Denmark)

    Nørrung, Birgit; Andersen, Jens Kirk

    2000-01-01

    A total of 245 strains of Listeria monocytogenes, representing 33 different electrophoretic types (ETs), were examined quantitatively for haemolytic activity. No significant difference was observed in the mean haemolytic activity between different ETs. Eighty four out of 91 strains examined were...... compared with 3.64 among food isolates). The explanation for this may be that more virulent strains are more prone to cause human infection. It is, however, also possible that strains oft. monocytogenes may become more virulent while multiplying in a living organism compared with multiplying in foods....

  15. Urban prevalence of Listeria spp. and Listeria monocytogenes in public lavatories and on shoe soles of facility patrons in the European capital city Vienna.

    Science.gov (United States)

    Schoder, D; Schmalwieser, A; Szakmary-Brändle, K; Stessl, B; Wagner, M

    2015-05-01

    The aim of this study was to determine the prevalence of Listeria spp. and Listeria monocytogenes (L. monocytogenes) in urban public lavatories and on shoe soles of facility patrons in a European capital city. More than 91% of all municipal public lavatories in Vienna close to public hubs were included in this study. Overall, 373 swab samples of public lavatories and shoes of facility patrons were enriched, according to ISO 11290-1. Listeria monocytogenes isolates were subtyped using pulsed-field gel electrophoresis. A total of 24 samples were positive for Listeria spp., yielding an overall prevalence of 6.4% (24/373). Listeria monocytogenes was found in 2.1% (8/373) of all samples. Swabs from lavatories in parks, container lavatories and lavatories at markets had the highest prevalences of 20.7% (6/29), 20% (2/10) and 12.5% (1/8) Listeria spp., respectively. These detection rates were statistically significantly higher than those associated with lavatories in shopping centres (P = 0.003, P = 0.002, P = 0.02) and at public transport locations (P = 0.0004, P = 0.005, P = 0.02). Shoes sampled at Christmas markets showed the highest Listeria spp. and L. monocytogenes prevalences of 80% (4/5) and 40% (2/5), respectively. With regard to shoe type, Listeria spp. detection rates were 14.3% (3/21; winter boots), 13.3% (2/15; hiking boots), sport shoes (5.9%; 2/34) and brogues (5.1%; 4/79). No Listeria spp. were found on shoe soles that had smooth treads (0/76), while Listeria spp. were detected on 19.5% (8/41) of medium depth tread shoe types and on 9.4% (3/32) of deep tread shoes. These data suggest that soil environment is still one of the most important reservoirs for the foodborne pathogen L. monocytogenes. © 2014 Blackwell Verlag GmbH.

  16. Isolation and detection of Listeria monocytogenes in poultry meat by standard culture methods and PCR

    Science.gov (United States)

    Kureljušić, J.; Rokvić, N.; Jezdimirović, N.; Kureljušić, B.; Pisinov, B.; Karabasil, N.

    2017-09-01

    Listeria is the genus of a bacteria found in soil and water and some animals, including poultry and cattle. It can be present in raw milk and food made from raw milk. It can also live in food processing plants and contaminate a variety of processed meats. Microscopically, Listeria species appear as small, Gram-positive rods, which are sometimes arranged in short chains. In direct smears, they can be coccoid, so they can be mistaken for streptococci. Longer cells can resemble corynebacteria. Flagella are produced at room temperature but not at 37°C. Haemolytic activity on blood agar has been used as a marker to distinguish Listeria monocytogenes among other Listeria species, but it is not an absolutely definitive criterion. Further biochemical characterization is necessary to distinguish between the different Listeria species. The objective of this study was to detect, isolate and identify Listeria monocytogenes from poultry meat. Within a period of six months from January to June 2017, a total of 15 samples were collected. Three samples were positive for the presence of Listeria monocytogenes. Biochemical and microbiological tests as well as PCR technique using specific primers were used to confirm L. Monocytogenes in the samples.

  17. Validation of the ANSR(®) Listeria monocytogenes Method for Detection of Listeria monocytogenes in Selected Food and Environmental Samples.

    Science.gov (United States)

    Caballero, Oscar; Alles, Susan; Le, Quynh-Nhi; Gray, R Lucas; Hosking, Edan; Pinkava, Lisa; Norton, Paul; Tolan, Jerry; Mozola, Mark; Rice, Jennifer; Chen, Yi; Ryser, Elliot; Odumeru, Joseph

    2016-01-01

    Work was conducted to validate performance of the ANSR(®) for Listeria monocytogenes method in selected food and environmental matrixes. This DNA-based assay involves amplification of nucleic acid via an isothermal reaction based on nicking enzyme amplification technology. Following single-step sample enrichment for 16-24 h for most matrixes, the assay is completed in 40 min using only simple instrumentation. When 50 distinct strains of L. monocytogenes were tested for inclusivity, 48 produced positive results, the exceptions being two strains confirmed by PCR to lack the assay target gene. Forty-seven nontarget strains (30 species), including multiple non-monocytogenes Listeria species as well as non-Listeria, Gram-positive bacteria, were tested, and all generated negative ANSR assay results. Performance of the ANSR method was compared with that of the U.S. Department of Agriculture, Food Safety and Inspection Service Microbiology Laboratory Guidebook reference culture procedure for detection of L. monocytogenes in hot dogs, pasteurized liquid egg, and sponge samples taken from an inoculated stainless steel surface. In addition, ANSR performance was measured against the U.S. Food and Drug Administration Bacteriological Analytical Manual reference method for detection of L. monocytogenes in Mexican-style cheese, cantaloupe, sprout irrigation water, and guacamole. With the single exception of pasteurized liquid egg at 16 h, ANSR method performance as quantified by the number of positives obtained was not statistically different from that of the reference methods. Robustness trials demonstrated that deliberate introduction of small deviations to the normal assay parameters did not affect ANSR method performance. Results of accelerated stability testing conducted using two manufactured lots of reagents predicts stability at the specified storage temperature of 4°C of more than 1 year.

  18. Listeria spp. in Street-Vended Ready-to-Eat Foods

    OpenAIRE

    El-Shenawy, Moustafa; El-Shenawy, Mohamed; Ma?es, Jordi; Soriano, Jose M.

    2011-01-01

    Street-vended ready-to-eat food sold in Egypt, including sandwiches and dishes of traditional food, was examined for the presence of Listeria species. Out of 576 samples, 24% were found to contain Listeria species. L. monocytogenes and L. innocua were isolated from 57% and 39% of the contaminated samples, respectively. Other Listeria spp. were detected with lower frequency. L. monocytogenes of ≥103 CFU/g were detected in 7% of the total examined samples, which represent 49% of the contamina...

  19. Listeria monocytogenes in Fresh Produce: Outbreaks, Prevalence and Contamination Levels

    Directory of Open Access Journals (Sweden)

    Qi Zhu

    2017-03-01

    Full Text Available Listeria monocytogenes, a member of the genus Listeria, is widely distributed in agricultural environments, such as soil, manure and water. This organism is a recognized foodborne pathogenic bacterium that causes many diseases, from mild gastroenteritis to severe blood and/or central nervous system infections, as well as abortion in pregnant women. Generally, processed ready-to-eat and cold-stored meat and dairy products are considered high-risk foods for L. monocytogenes infections that cause human illness (listeriosis. However, recently, several listeriosis outbreaks have been linked to fresh produce contamination around the world. Additionally, many studies have detected L. monocytogenes in fresh produce samples and even in some minimally processed vegetables. Thus L. monocytogenes may contaminate fresh produce if present in the growing environment (soil and water. Prevention of biofilm formation is an important control measure to reduce the prevalence and survival of L. monocytogenes in growing environments and on fresh produce. This article specifically focuses on fresh produce–associated listeriosis outbreaks, prevalence in growing environments, contamination levels of fresh produce, and associated fresh produce safety challenges.

  20. Celulitis por citomegalovirus

    Directory of Open Access Journals (Sweden)

    A. Ruiz Lascano

    2002-12-01

    Full Text Available Las lesiones cutáneas por citomegalovirus (CMV son infrecuentes y a menudo una manifestación tardía de una enfermedad sistémica, que generalmente anuncia un curso fatal. Comunicamos un caso de celulitis por CMV: una mujer de 70 años con trasplante renal efectuado 1 mes antes de la consulta, terapia inmunosupresora con ciclosporina A y metilprednisona. La paciente ingresó por fiebre, dolor e impotencia funcional en pierna derecha. Comprobamos la existencia de una placa de 8 por 4 cm eritematoedematosa. La tratamos con antibióticos sin mejoría, por lo que realizamos un estudio histopatológico de piel que mostró cambios citopáticos compatibles con infección por CMV. Los cultivos bacteriológicos y micológicos fueron negativos. La inmunohistoquímica específica para CMV y el estudio de reacción en cadena de la polimerasa (PCR de la biopsia de piel fueron positivas, al igual que la antigenemia. El tratamiento con ganciclovir produjo la mejoría del cuadro clínico. En la literatura revisada no hemos encontrado la celulitis como manifestación de enfermedad cutánea por CMV.

  1. Sublethal injury and virulence changes in Listeria monocytogenes and Listeria innocua treated with antimicrobials carvacrol and citral.

    Science.gov (United States)

    Silva, A; Genovés, S; Martorell, P; Zanini, S F; Rodrigo, D; Martinez, A

    2015-09-01

    The aim of this study was to evaluate the effect of two antimicrobial substances, carvacrol and citral, on Listeria monocytogenes and Listeria innocua cells, as well as possible virulence changes in injured cells, using Caenorhabditis elegans as a model test. The results indicated that the percentage of sublethal damage was higher in L. monocytogenes than in L. innocua. The results of the study carried out by using C. elegans indicated that C. elegans fed in a lawn of L. monocytogenes previously treated with carvacrol showed a loss in life span (p ≤ 0.05) as compared with L. monocytogenes treated with citral, Escherichia coli OP50 as a negative control, and treated and untreated L. innocua. Egg laying was also affected: worms fed in a lawn of treated and untreated L. monocytogenes laid fewer eggs than those fed in a lawn of treated and untreated L. innocua or fed with OP50 as a negative control. Worms fed in a lawn of treated and untreated L. innocua also laid fewer eggs than those fed with OP50 as a negative control. A phenotype named bag of worms and an undescribed new one, "vulva inflammation", were also observed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Linezolid and dexamethasone experience in a serious case of listeria rhombencephalitis.

    Science.gov (United States)

    Yılmaz, Pakize Ö; Mutlu, Nevzat M; Sertçelik, Ahmet; Baştuğ, Aliye; Doğu, Cihangir; Kışlak, Sümeyye

    2016-01-01

    Listeria rhombencephalitis is a rare cause of brain stem encephalitis. We report a case with a history of immunosupressive therapy due to Takayasu's arteritis that was treated with corticosteroids and linezolid for Listeria rhombencephalitis. A 63-year-old woman was admitted to the hospital with fever, headache, nausea, and vomiting. The patient's body temperature was 38°C, and she had a stiff neck. Listeria monocytogenes was isolated from the cerebrospinal fluid (CSF), and penicillin G and gentamicin treatment was initiated. Linezolid and dexamethasone were added. Due to hematuria and thrombocytopenia, the linezolid was discontinued. In immunocompromised patients with CNS infections, Listeria rhombencephalitis should be suspected. Linezolid can be used in combination with dexamethasone. Copyright © 2016 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  3. Isolation and Confirmation of Listeria Species from Seafood off Goa Region by Polymerase Chain Reaction.

    Digital Repository Service at National Institute of Oceanography (India)

    Gawade, L.; Barbuddhe, S.B.; Bhosle, S.

    Several food borne outbreaks have highlighted the importance of Listeria monocytogenes to the public health and have been recognized as an emerging, important food borne pathogen, and a causative agent of listerioses. A number of genes are involved...

  4. Characteristics of the biologically active 35-kDa metalloprotease virulence factor from Listeria monocytogenes

    NARCIS (Netherlands)

    Coffey, A; van den Burg, B; Veltman, R; Abee, T

    Listeria monocytogenes, a facultative intracellular pathogen, synthesizes an extracellular protease which is responsible for the maturation of phosphatidylcholine phospholipase C (lecithinase), a virulence factor involved in cell-to-cell spread. This work describes the environmental parameters

  5. Internalization of Listeria monocytogenes in cantaloupes during dump tank washing and hydrocooling

    Science.gov (United States)

    Recent listeriosis outbreaks and recalls associated with cantaloupes urge for studies to understand the mechanisms of cantaloupe contamination by Listeria monocytogenes. Postharvest practices such as washing and hydrocooling were suggested to facilitate the contamination of fresh fruits by human pat...

  6. Growth inhibition of Listeria spp. on Camembert cheese by bacteria producing inhibitory substances.

    Science.gov (United States)

    Sulzer, G; Busse, M

    1991-12-01

    Bacterial strains exhibiting antimicrobial activity towards other bacteria are quite common in nature. During the past few years several genera have been shown to exert inhibitory action against Listeria. spp. In the present work strains of Enterococcus, Lactobacillus and Lactococcus were tested for their influence on the development of Listeria spp. on Camembert cheese. Partial or complete inhibition of growth of Listeria spp. was observed using various inhibitory bacteria. Complete inhibition occurred when the inhibitory strain was used as a starter culture and there was a low level of contamination with Listeria spp. during the first stage of ripening. Very little inhibition occurred if the inhibitory strain was added together with the starter culture.

  7. Diversity Assessment of Heat Resistance of Listeria monocytogenes Strains in a Continuous-Flow Heating System

    NARCIS (Netherlands)

    Veen, van der S.; Wagendorp, A.; Abee, T.; Wells-Bennik, M.H.J.

    2009-01-01

    Listeria monocytogenes is a foodborne pathogen that has the ability to survive relatively high temperatures compared with other nonsporulating foodborne pathogens. This study was performed to determine whether L. monocytogenes strains with relatively high heat resistances are adequately inactivated

  8. Research and identification of pathogenic bacteria 'Salmonella and Listeria' in food

    International Nuclear Information System (INIS)

    Harizi Khalil

    2009-01-01

    The sums propose to evaluate the bacterial contamination of certain food taken randomly by two pathogenic bacteria (Salmonella and Listeria) considering the evolution of the diseases of food oignon. For that 78 food samples of different origins were analysed. 2 stocks of the Listeria kind and 3 stocks of the salmonella kind were insulated and identified by biochemical and molecular tests. The pathogenic isolates were identified by coloration gram, test catalase, insulation on specific culture media and Api (20 E for Salmonella and Api listeria. At the end, the PCR were realized to amplify the gene iap which codes for the protein p60 at listeria as well as a sequence clonee randomly specific of Salmonella.

  9. Occurrence and genetic characterization of Listeria spp. in minimally processed vegetables commercialized in Porto Alegre, Brazil

    OpenAIRE

    Verdin, Sylvia Elisa Frizzo; Silva, Silvia Regina Pavan da; Pereira, Dariane Castro; Schatkoski, Aline Modelski; Corção, Gertrudes

    2007-01-01

    Minimally processed vegetables go through many steps before they are refrigerated, selection, washing, peeling, cutting, disinfection and finally packaging. However, if no care is taken at the origin of the raw materials and in the processing stages, there is a chance of finding pathogenic bacteria, such as Listeria monocytogenes, which are able to grow at low temperatures. The aim of this research was to verify the occurrence of Listeria sp. in minimally processed vegetables sold in Porto Al...

  10. Coupling conducting polymers and mediated electrochemical responses for the detection of Listeria

    International Nuclear Information System (INIS)

    Minett, A.I.; Barisci, J.N.; Wallace, G.G.

    2003-01-01

    Different signal generation techniques were investigated for the development of a biosensor for Listeria monocytogenes. Conventional amperometry at an antibody-containing polypyrrole film electrode was found to be unsuccessful in detecting levels below 10 6 cells ml -1 . More successful was the coupling of a covalently modified film with the use of electron mediators in a single device. This sensor was capable of reproducibly detecting Listeria at levels of 10 5 cells ml -1 in 30 min

  11. Prevalence and contamination patterns of Listeria monocytogenes in catfish processing environment and fresh fillets.

    Science.gov (United States)

    Chen, Bang-Yuan; Pyla, Rajkumar; Kim, Tae-Jo; Silva, Juan L; Jung, Yean-Sung

    2010-08-01

    Catfish skins, intestines, fresh fillets, processing surfaces at different production stages, chiller water and non-food contact surfaces were sampled for Listeria monocytogenes and other Listeria species. Among 315 samples, prevalence of L. monocytogenes, Listeria innocua and a group of Listeria seeligeri-Listeria welshimeri-Listeria ivanovii was 21.6, 13.0 and 29.5%, respectively. No Listeria grayi was detected in this survey. While no L. monocytogenes strains were isolated from catfish skins and intestines, the strains were found with a frequency of 76.7% in chilled fresh catfish fillets and 43.3% in unchilled fillets. L. monocytogenes and Listeria spp. were also detected in fish contact surfaces such as deheading machine, trimming board, chiller water, conveyor belts at different stages, and fillet weighing table. Among L. monocytogenes, 1/2b (47.0%), 3b (16.0%) and 4c (14%) were the predominant serotypes isolated, whereas 4b, 4e, 1/2c and 1/2a were detected at much lower frequencies. Genotype analyses of L. monocytogenes isolates using serotyping, pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus (ERIC)-PCR revealed that chiller water represented an important contamination source of L. monocytogenes in the chilled catfish fillets of two processing facilities, whereas fillet weighing table significantly contributed to the catfish fillet contamination of the third facility. This study suggests that L. monocytogenes contamination in the processed catfish fillets originates from the processing environment, rather than directly from catfish. Results from this study can aid the catfish industry to develop a plant-specific proper cleaning and sanitation procedure for equipment and the processing environment designed to specifically target L. monocytogenes contamination. Copyright 2010 Elsevier Ltd. All rights reserved.

  12. The influence of Listeria monocytogenes cells on the primary immunologic response in irradiated mice

    International Nuclear Information System (INIS)

    Borowski, J.; Jokoniuk, P.

    1977-01-01

    The influence of killed Listeria monocytogenes cells on the primary immunologic response in mice irradiated with 300 or 500 R was studied. The immunologic response of the mice to sheep red blood cells used as antigen was assessed at the cellular level (by counting PFC) and humoral level. Injection of killed Listeria monocytogenes cells before irradiation of the mice diminished the immunosuppressive effect of roentgen radiation. Injection of the cells after irradiation accelerated regeneration of immunologic reactivity in the irradiated mice. (author)

  13. Distribution of the bacteria Listeria monocytogenes in the western part of the Sea of Okhotsk

    Science.gov (United States)

    Terekhova, V. E.; Sosnin, V. A.; Buzoleva, L. S.; Shakirov, R. B.

    2010-04-01

    The Amur River’s influence on the distribution of the opportunistic bacteria Listeria monocytogenes in the western part of the Sea of Okhotsk is discussed. The presence of Listeria in the seawater, sea ice, and sediments on the northeastern Sakhalin shelf and slope supports the idea of its connection with the Amur River discharge. The hypothesis of the allochtonic parentage of L. monocytogenes in the sea’s development is proved.

  14. Comparison of the incidence of Listeria on equipment versus environmental sites within dairy processing plants.

    Science.gov (United States)

    Pritchard, T J; Flanders, K J; Donnelly, C W

    1995-08-01

    This study was undertaken to compare the incidence of Listeria contamination of processing equipment with that of the general dairy processing environment. A total of 378 sponge samples obtained from 21 dairy plants were analyzed for Listeria using three different enrichment media. Use of extended microbiological analysis allowed us to identify 26 Listeria positive sites which would have not been identified had a single test format been employed. Eighty (80) of 378 sites (21.2%) were identified as Listeria positive. Listeria innocua was isolated from 59 of the 80 (73.8%) positive samples, L. monocytogenes was identified in 35 (43.8%) of the positive samples, and L. seeligeri was isolated from 5 (6.3%) of the Listeria positive samples. Positive equipment samples were obtained from 6 of the 21 (28.6%) plants and 19 of the 21 (90.5%) plants had positive environmental sites. Seventeen of the 215 (7.9%) samples from equipment were positive for Listeria species. Eleven of these sites, including 3 holding tanks, 2 table tops, 3 conveyor/chain systems, a pasta filata wheel, a pint milk filler and a brine pre-filter machine, were positive for L. monocytogenes. Nineteen of the 21 (90.5%) plants had positive environmental sites. Sixty-three of the 163 (41.1%) samples from environmental sites were Listeria positive and 24 were positive for L. monocytogenes. Two-tailed student t-test analysis of the mean frequencies indicated that the level of contamination was significantly higher (p plant, and that greater emphasis needs to be placed on the cleaning and sanitizing of the plant environment.

  15. Prevalence of listeria, Aeromonas, and Vibrio species in fish used for human consumption in Turkey.

    Science.gov (United States)

    Yücel, Nihal; Balci, Senay

    2010-02-01

    A total of 78 raw retail fish samples from 30 freshwater and 48 marine fish were examined for the presence of Listeria, Aeromonas, and Vibrio species. The overall incidence of Listeria spp. was 30% in freshwater samples and 10.4% in marine fish samples. Listeria monocytogenes (44.5%) was the most commonly isolated species in freshwater fish, and Listeria murrayi (83.5%) was the most commonly isolated species in marine fish samples. Motile aeromonads were more common in marine fish samples (93.7%) than in freshwater fish samples (10%). Vibrio alginolyticus, Vibrio fluvialis, and Vibrio damsela were isolated only in marine fish samples, representing 40.9, 38.6, and 36.3% of Vibrio isolates, respectively. In freshwater and marine fish, the highest incidences of Listeria and Aeromonas were found in skin samples; the highest incidence of Vibrio in marine fish was found in gill samples. The location of Listeria spp. and L. monocytogenes in a fish was significantly different among freshwater fish. A high incidence of these bacterial pathogens was found in the brown trout (Salmo trutta) and horse mackerel (Trachurus trachurus). Handling of contaminated fish, cross-contamination, or eating raw fish might pose a health hazard, especially in immunosuppressed individuals, elderly people, and children. This study highlights the importance of bacterial pathogens in fish intended for human consumption, but more study is needed.

  16. Prevalence and serotypes of Listeria monocytogenes contamination in Chinese beef processing plants.

    Science.gov (United States)

    Zhu, Lixian; Feng, Xiaohui; Zhang, Lihua; Zhu, Ruiliang; Luo, Xin

    2012-06-01

    The aim of this work was to study the epidemiology of Listeria spp., particularly Listeria monocytogenes, and to identify the serotypes present in contaminated samples from beef processing plants in China. A total of 439 samples were obtained from bovine feces, hides, and carcasses at three commercial processing plants. A standard protocol (ISO 11290-1) was followed to detect Listeria spp. and L. monocytogenes, and multiplex polymerase chain reaction was used to identify the various L. monocytogenes serotypes. The overall prevalences of Listeria spp. and L. monocytogenes were 65.6% and 26.4%, respectively, and the contamination was highest in the hide samples. The identified L. monocytogenes serotypes were 1/2c and 1/2a. The results of the current study indicate that Listeria spp. contamination is common in Chinese beef processing plants; specific measures should be taken to prevent and/or treat L. monocytogenes contamination of feces and hides in beef slaughter plants. Furthermore, because Listeria spp. contamination was found to be prevalent, it should, therefore, be studied further. The prevention of cases of sporadic listeriosis in China should also be addressed.

  17. Prevalence of and risk factors for Listeria species on dairy farms.

    Science.gov (United States)

    Vilar, M J; Yus, E; Sanjuán, M L; Diéguez, F J; Rodríguez-Otero, J L

    2007-11-01

    This cross-sectional study determined the prevalence of Listeria spp. in bulk-tank milk on dairy farms in the region of Galicia in northwest Spain. The aim was to identify management practices associated with the presence of Listeria spp. and possible effects on milk hygienic quality. A total of 98 farms was randomly selected on the basis of an expected prevalence of 6.5% for Listeria monocytogenes from 20,107 dairy farms in the region. Bulk-tank milk samples were obtained from 98 farms, fecal samples from lactating cows from 97 farms, and silage samples from 83 farms. Listeria monocytogenes was detected in 6.1, 9.3, and 6.0% of these samples, respectively. Statistical analyses confirmed the relationship between low silage quality (as indicated by high pH) and presence of Listeria spp. in silage (29.5 vs. 6.2% for pH above or below 4.5, respectively). Only milking system [tie-stall systems (28.6%) vs. parlor milking (10%)] and inadequately controlled milking order [yes (32.0%) vs. no (10.7%)] had statistically significant effects on management practices for increasing the risk of Listeria contamination of bulk-tank milk.

  18. Control of Listeria species food safety at a poultry food production facility.

    Science.gov (United States)

    Fox, Edward M; Wall, Patrick G; Fanning, Séamus

    2015-10-01

    Surveillance and control of food-borne human pathogens, such as Listeria monocytogenes, is a critical aspect of modern food safety programs at food production facilities. This study evaluated contamination patterns of Listeria species at a poultry food production facility, and evaluated the efficacy of procedures to control the contamination and transfer of the bacteria throughout the plant. The presence of Listeria species was studied along the production chain, including raw ingredients, food-contact, non-food-contact surfaces, and finished product. All isolates were sub-typed by pulsed-field gel electrophoresis (PFGE) to identify possible entry points for Listeria species into the production chain, as well as identifying possible transfer routes through the facility. The efficacy of selected in-house sanitizers against a sub-set of the isolates was evaluated. Of the 77 different PFGE-types identified, 10 were found among two or more of the five categories/areas (ingredients, food preparation, cooking and packing, bulk packing, and product), indicating potential transfer routes at the facility. One of the six sanitizers used was identified as unsuitable for control of Listeria species. Combining PFGE data, together with information on isolate location and timeframe, facilitated identification of a persistent Listeria species contamination that had colonized the facility, along with others that were transient. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Prevalence of Listeria monocytogenes in the river receiving the effluent of municipal wastewater treatment plant

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    Atefeh Taherkhani

    2013-01-01

    Full Text Available Aims: The objective of this study was to evaluate the prevalence of Listeria spp. in the river water before and after discharge of the effluent of the municipal wastewater treatment plant (WWTP in Isfahan, Iran. Materials and Methods: A total of 66 samples were collected bi-weekly over 4 months from eleven discrete sampling locations in Zayandehrood River, Iran. Three sampling sites were located above the discharge point and five sites were located after the discharge point of WWTP. Samples were also collected from the influent and the effluent of WWTP. Listeria spp. were isolated using a selective enrichment procedure and a subculture onto polymyxin-acriflavine-lithium chloride-ceftazidime-esculin-mannitol Agar. All isolates were subjected to standard biochemical tests. Results: L. monocytogenes was isolated from influent (83%, effluent (50% and (18.5% river water. Listeria spp. was not found before the discharge point in river water. However, L. monocytogenes was isolated in samples collected from 200 m (33%, 500 m (33%, 2 km (16.5%, 5 km (16.5% and 10 km (16.5% downstream from the WWTP. Listeria innocua (9% and Listeria seeligeri (10% were the second most frequently isolated species. Conclusion: During the wastewater treatment, Listeria spp. is not removed completely. L. monocytogenes is widely distributed in the Zayandehrood river. L. monocytogenes released into surface water demonstrates a potential risk for public health. These results indicate the need for appropriate water management in order to reduce human and animal exposure to such pathogens.

  20. Prevalence of Listeria monocytogenes in raw bovine milk and milk products from central highlands of Ethiopia.

    Science.gov (United States)

    Seyoum, Eyasu Tigabu; Woldetsadik, Daniel Asrat; Mekonen, Tesfu Kassa; Gezahegn, Haile Alemayehu; Gebreyes, Wondwossen Abebe

    2015-11-30

    Listeria monocytogenes is of major significance in human and veterinary medicine. Most human Listeria infections are foodborne and the association of contaminated milk and dairy produce consumption with human listeriosis is noteworthy. In Ethiopia, there is limited data regarding the prevalence of L. monocytogenes in raw bovine milk and dairy products. The aim of this study was, therefore, to determine the prevalence of L. monocytogenes in raw bovine milk and dairy produce. A total of 443 milk and milk product samples were microbiologically analyzed following methods recommended by the U.S. Food and Drug Administration Bacteriological Analytical Manual to isolate Listeria spp. The overall prevalence of Listeria spp. was 28.4% and specifically that of L. monocytogenes was 5.6%. Taking the prevalence of Listeria spp. into consideration, cheese was found to be highly contaminated at 60%, followed by pasteurized milk samples (40%), raw milk (18.9%) and yoghurt (5%). Considering the prevalence of Listeria monocytogenes only, raw milk had the lowest contamination while cheese had the highest, followed by pasteurized milk and yoghurt. Raw milk and milk products produced in urban and peri-urban areas of central Ethiopia were contaminated with pathogenic bacteria, L. monocytogenes. The detection of this pathogen in raw milk and milk products warrants an urgent regulatory mechanism to be put in place and also the potential role of milk processing plants in the contamination of dairy products should be investigated.

  1. Identification of non-Listeria spp. bacterial isolates yielding a β-D-glucosidase-positive phenotype on Agar Listeria according to Ottaviani and Agosti (ALOA).

    Science.gov (United States)

    Angelidis, Apostolos S; Kalamaki, Mary S; Georgiadou, Sofia S

    2015-01-16

    Agar Listeria according to Ottaviani and Agosti (ALOA) is the mandatory medium used for the detection and enumeration of Listeria monocytogenes in foods according to the official International Organization for Standardization (ISO) methods. On ALOA, Listeria spp. appear as bluish-green colonies due to the production of β-D-glucosidase, an enzyme that cleaves 5-bromo-4-chloro-3-indolyl-β-D-glucopyranoside, a chromogenic substrate included in the formulation of the medium. The present work reports on bacterial isolates (n=64) from ready-to-eat soft cheeses, which are able to grow on ALOA, forming bluish-green colonies and therefore phenotypically resemble Listeria spp. All isolates were also capable of growing on the selective media PALCAM and RAPID L'mono. The isolates were characterised with biochemical tests including those specified in the ISO standards for the confirmation of Listeria spp. and identified via partial sequencing of their 16S rRNA gene. According to sequencing results the isolates represented 12 different bacterial species or species-groups belonging to seven different genera: Bacillus spp. (B. circulans, B. clausii, B. licheniformis and B. oleronius), Cellulosimicrobium spp. (C. funkei), Enterococcus spp. (E. faecalis, E. faecium/durans), Kocuria spp. (K. kristinae), Marinilactibacillus spp. (M. psychrotolerans), Rothia spp. (R. terrae) and Staphylococcus spp. (S. sciuri and S. saprophyticus subsp. saprophyticus/xylosus). Cellulosimicrobium spp. have never been previously isolated from foods. These results significantly extend the list of bacteria previously known as capable of growing on ALOA as bluish-green colonies and suggest that there may be room for further improvement in the medium's inhibitory properties towards non-Listeria spp., Gram-positive bacteria present in foods. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Detection of Listeria spp. in food handling areas of retail food stores in the state of Pernambuco, Brazil

    Directory of Open Access Journals (Sweden)

    Mariana Gomes Ferreira Machado de Siqueira

    2017-07-01

    Full Text Available Abstract The identification of Listeria spp. in food handling areas is of great concern to health surveillance agencies, and their control is often hampered by the ability of the bacteria to grow and maintain themselves even under adverse conditions. The present study aimed to isolate and identify Listeria spp. in the food handling areas of 10 retail food stores in the state of Pernambuco, Brazil. Eighty-six swab samples were collected from equipment, utensils and surfaces used for processing ready-to-eat meat products. The Dry and Wet Swabbing Methods (3M™ Quick Swabs and 3M™ Petrifilm™ Plates were used to identify Listeria spp. Contamination by Listeria monocytogenes was confirmed by the Real-time Polymerase Chain Reaction (qPCR. The hygienic and sanitary conditions of the food handling areas of each store were also assessed. Listeria spp. was isolated in eight stores (80%. Of the 86 swab samples analyzed, 27 (31.2% [confidence interval 21.81% to 42.30%] were positive for Listeria spp. and only one (3.7% was confirmed as Listeria monocytogenes. The main contamination sites were the floor (50.0%, the plastic cutting board (42.9% and the knife (40.0%. None of the hygienic and sanitary conditions assessed in the present study were associated with contamination by Listeria spp. (p = 0.700. It was concluded that Listeria spp. was widely distributed in the retail food stores studied, being a possible risk factor for public health.

  3. Listeria monocytogenes Meningitis in an Immunosuppressed Patient with Autoimmune Hepatitis and IgG4 Subclass Deficiency

    DEFF Research Database (Denmark)

    Gaini, Shahin

    2015-01-01

    A 51-year-old Caucasian woman with Listeria monocytogenes meningitis was treated and discharged after an uncomplicated course. Her medical history included immunosuppressive treatment with prednisolone and azathioprine for autoimmune hepatitis. A diagnostic work-up after the meningitis episode...... revealed that she had low levels of the IgG4 subclass. To our knowledge, this is the first case report describing a possible association between autoimmune hepatitis and the occurrence of Listeria monocytogenes meningitis, describing a possible association between Listeria monocytogenes meningitis...... and deficiency of the IgG4 subclass and finally describing a possible association between Listeria monocytogenes meningitis and immunosuppressive therapy with prednisolone and azathioprine....

  4. Phages of Listeria offer novel tools for diagnostics and biocontrol

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    Martin J Loessner

    2014-04-01

    Full Text Available Historically, bacteriophages infecting their hosts have perhaps been best known and even notorious for being a nuisance in dairy-fermentation processes. However, with the rapid progress in molecular microbiology and microbial ecology, a new dawn has risen for phages. This review will provide an overview on possible uses and applications of Listeria phages, including phage-typing, reporter phage for bacterial diagnostics, and use of phage as biocontrol agents for food safety. The use of phage-encoded enzymes such as endolysins for the detection and as antimicrobial will also be addressed. Desirable properties of candidate phages for biocontrol will be discussed. While emphasizing the enormous future potential for applications, we will also consider some of the intrinsic limitations dictated by both phage and bacterial ecology.

  5. Spontaneous Bacterial Peritonitis Caused by Infection with Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    Michael Vincent F. Tablang

    2008-11-01

    Full Text Available Spontaneous bacterial peritonitis is a severe and life-threatening complication in patients with ascites caused by advanced liver disease. The organisms most commonly involved are coliform bacteria and third-generation cephalosporins are the empiric antibiotics of choice. This is an uncommon case of spontaneous bacterial peritonitis caused by Listeria monocytogenes in a female patient with liver cirrhosis from autoimmune hepatitis. She did not improve with ceftriaxone and her course was complicated by hepatic encephalopathy, seizures and multi-organ failure. This case emphasizes that a high index of suspicion should be maintained for timely diagnosis and treatment. Listerial peritonitis should be suspected in patients with end-stage liver disease and inadequate response to conventional antibiotics within 48–72 h. Ampicillin/sulbactam should be initiated while awaiting results of ascitic fluid or blood culture.

  6. Inactivation of Listeria monocytogenes in milk by pulsed electric field.

    Science.gov (United States)

    Reina, L D; Jin, Z T; Zhang, Q H; Yousef, A E

    1998-09-01

    Pasteurized whole, 2%, and skim milk were inoculated with Listeria monocytogenes Scott A and treated with high-voltage pulsed electric field (PEF). The effects of milk composition (fat content) and PEF parameters (electric field strength, treatment time, and treatment temperature) on the inactivation of the bacterium were studied. No significant differences were observed in the inactivation of L. monocytogenes Scott A in three types of milk by PEF treatment. With treatment at 25 degrees C, 1- to 3-log reductions of L. monocytogenes were observed. PEF lethal effect was a function of field strength and treatment time. Higher field strength or longer treatment time resulted in a greater reduction of viable cells. A 4-log reduction of the bacterium was obtained by increasing the treatment temperature to 50 degrees C. Results indicate that the use of a high-voltage PEF is a promising technology for inactivation of foodborne pathogens.

  7. Review of Prosthetic Joint Infection from Listeria monocytogenes.

    Science.gov (United States)

    Bader, Gilbert; Al-Tarawneh, Mohammed; Myers, James

    2016-12-01

    Prosthetic joint infection from Listeria monocytogenes is rare. We decided to shed light on this illness and review the reported cases to better understand its characteristics. We conducted a comprehensive review of the English literature using PubMed. We also included one case that we had managed. We found 25 cases of prosthetic joint infection from L. monocytogenes reported individually and a retrospective study of 43 cases of joint and bone listerial infection, including 34 with prosthetic joint infection, conducted in France. We have described their clinical and para-clinical features and tried to elaborate on the pathophysiology, treatment, and prevention. Prosthetic joint infection from L. monocytogenes is mainly late. Systemic inflammation may be absent. Although rare, it must be suspected in patients at high risk for both prosthetic joint and listerial infections. In addition, those patients must be instructed on appropriate preventive measures.

  8. Listeria monocytogenes response regulators important for stress tolerance and pathogenesis

    DEFF Research Database (Denmark)

    Kallipolitis, B H; Ingmer, H

    2001-01-01

    Environmental sensing by two-component signal transduction systems is likely to play a role for growth and survival of Listeria monocytogenes both during transmission in food products and within a host organism. Two-component systems typically consist of a membrane-associated sensor histidine...... kinase and a gene regulatory protein, the response regulator (RR). We have identified seven putative RR genes in L. monocytogenes LO28 by PCR using degenerate oligonucleotide primers. By insertional inactivation we obtained data suggesting that three of the putative RRs contribute to the pathogenicity...... of L. monocytogenes in mice. Strikingly, the mutants that were attenuated in virulence also had a decreased ability to grow in the presence of various stress conditions potentially encountered in an infection process. Thus, our data point to a connection between the ability of the putative two...

  9. Animal models for oral transmission of Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    Sarah E F D'Orazio

    2014-02-01

    Full Text Available Listeria monocytogenes has been recognized as a food borne pathogen in humans since the 1980s, but we still understand very little about oral transmission of L. monocytogenes or the host factors that determine susceptibility to gastrointestinal infection, due to the lack of an appropriate small animal model of oral listeriosis. Early feeding trials suggested that many animals were highly resistant to oral infection, and the more reproducible intravenous or intraperitoneal routes of inoculation soon came to be favored. There are a fair number of previously published studies using an oral infection route, but the work varies widely in terms of bacterial strain choice, the methods used for oral transmission, and various manipulations used to enhance infectivity. This mini review will summarize the published literature using oral routes of L. monocytogenes infection and will highlight recent technological advances that have made oral infection a more attractive model system.

  10. Listeria monocytogenes: UM AGENTE INFECCIOSO AINDA POUCO CONHECIDO NO BRASIL

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    C. D. CRUZ

    2009-01-01

    Full Text Available

    Listeria monocytogenes é o agente infeccioso responsável pela doença de origem alimentar denominada listeriose. Apesar de baixa incidência, a listeriose representa importante risco à saúde pública, pelo grau de severidade das seqüelas e alto índice de mortalidade (20% a 30% que promove em populações de risco, como pacientes imunocomprometidos, idosos e gestantes. No Brasil e em outros países em desenvolvimento, além da falta de preocupação por parte das autoridades de saúde pública em relação à sua disseminação, não há estatísticas oficiais de casos de listeriose, pois sua notifi cação não é obrigatória. Considerando o aumento da incidência de L. monocytogenes no mundo todo, e a falta de informações atualizadas na língua portuguesa sobre o comportamento desta bactéria, sua prevalência, fatores de virulência e outros aspectos relevantes para a saúde pública, se elaborou esta revisão.

  11. Combination of endolysins and high pressure to inactivate Listeria monocytogenes.

    Science.gov (United States)

    van Nassau, Tomas J; Lenz, Christian A; Scherzinger, Anna S; Vogel, Rudi F

    2017-12-01

    Outbreaks of listeriosis are often related to the consumption of low-processed ready-to-eat food products (e.g. soft cheeses or smoked fish) contaminated with Listeria monocytogenes. Traditional preservation techniques, such as heat treatment, cannot eliminate Listeria from these products without strongly affecting the quality of the foods. We therefore investigated the use of endolysin (PlyP40, Ply511, or PlyP825) in combination with high hydrostatic pressure processing to kill L. monocytogenes in buffer. The results demonstrated a more than additive effect when both treatments were combined. For example, whereas 0.16 μg/mL PlyP825 or 300 MPa (1 min, 30 °C) applied individually reduced the cell count by 0.2 and 0.3 log cfu, respectively, a combined treatment resulted in a reduction of 5.5 log cfu. Similar results were obtained for the other endolysins combined with high pressure processing. We also showed that the synergistic inactivation of cells by endolysin and HHP is possible at a pressure level of only 200 MPa (2 min, 30 °C). Thus, the application of endolysins did not only substantially increase the bactericidal effect of high pressure, but it also enabled the inactivation of bacterial cells at much lower pressure levels. This shows the potential of using such combined processes for the inactivation of L. monocytogenes and food preservation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Antimicrobial treatments to control Listeria monocytogenes in queso fresco.

    Science.gov (United States)

    Lourenço, António; Kamnetz, Mary B; Gadotti, Camila; Diez-Gonzalez, Francisco

    2017-06-01

    Queso fresco, is a Hispanic non-fermented cheese highly susceptible to contamination with L. monocytogenes. This research was aimed to determine the effect of GRAS antimicrobial ingredients to control L. monocytogenes. Antimicrobials included caprylic acid (CA), Nisaplin ® (N, 2.5% nisin), a mixture of sodium lactate and sodium diacetate (SL/SD), Lactococcus lactis sbp. lactis DPC 3147, monolaurin, and lactic acid (LA). Batches of queso fresco curds were inoculated with 10 4  CFU/g and stored at 4 °C for three weeks. During storage the count of L. monocytogenes reached 7 to 8 Log CFU/g in control samples. Most individual antimicrobial treatments resulted in less than 1 Log CFU/g reductions in final counts, with the exception of N (0.5 g/kg) and CA (2.9 g/kg) that caused more than 3 and 5 Log CFU/g differences with controls, respectively. Mixtures of ingredients were more effective in inhibiting L. monocytogenes growth, and treatments with N and CA consistently delivered 6 Log CFU/g less counts than controls. Supplementation of 12 g/kg LA to treatments with SL/SD (3%/0.22%) caused differences of more than 4 Log CFU/g in final Listeria populations. Samples treated with the binary mixtures of N and CA (0.5 and 0.7 g/kg, respectively) were evaluated in a consumer panel (n = 67). Panelists slightly preferred control and commercial over treated samples, but all samples were in average rated between "slightly liking" and "moderately liking." These experiments indicated that combined use of antimicrobial ingredients may be an effective way to control the population of Listeria monocytogenes in queso fresco. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Survival of Listeria monocytogenes in low acid italian sausage produced under brazilian conditions Sobrevivência de Listeria monocytogenes em salame tipo italiano de baixa acidez, produzido sob condições brasileiras de fabricação

    Directory of Open Access Journals (Sweden)

    Roberto Degenhardt

    2007-06-01

    Full Text Available Dry sausages have been considered ready-to-eat products with low risk of causing listeriosis due to the hurdles created during the manufacturing process such as low pH and a w, high salt concentration and presence of lactic acid bacteria (LAB. However, several studies have detected survival of Listeria monocytogenes in these products and also shown that process parameters, LAB and L. monocytogenes strains directly influence the results. In this work, survival of the pathogen in sausages prepared with three different formulations (one standard formulation, one formulation added of Lactobacillus plantarum and one added of 2% sodium lactate, using the manufacturing process usually employed in Brazil, was evaluated. Naturally contaminated sausages presented a small increase in the counts of L. monocytogenes in the first days of the process, followed by a gradual decrease until the end of the process. In experimentally contaminated samples containing L. plantarum, the reduction of counts of L. monocytogenes during processing was considerable, but there wasn´t significant differences between the treatments.Salames têm sido considerados produtos prontos para o consumo com baixo risco de provocar listeriose devido aos obstáculos criados no processo de fabricação e suas características de pH e atividade água baixos, alta concentração de sal e presença de bactérias lácticas. Entretanto, a sobrevivência de Listeria monocytogenes nesta classe de produtos é verificada e estudos de processo visando à redução da contaminação por este patógeno, têm demonstrado que particularidades como variação dos parâmetros de processo, cepas de bactérias lácticas e de L. monocytogenes influenciam diretamente os resultados. Neste estudo três formulações foram avaliadas (uma padrão, uma com inoculação da cultura Lactobacillus plantarum e outra com adição 2% de lactato de sódio empregando parâmetros de processo comumente praticados no Brasil

  14. Electrocardiografo por computadora

    OpenAIRE

    Tinoco Hernandez, Rosanna; Paredes Bejarano, Margarita; Romero Chaglia, Norman; Yapur Auad, Miguel Eduardo

    2009-01-01

    El presente trabajo trata sobrees el diseño y la implementación de un graficador de señales cardiacas por computadora, para lo cual diseñamos un circuito electrónico capaz de recibir la senal analógica proveniente de la actividad electrica del corazón , amplificarla, y luego convertirla en una señal digital para ser procesada por software y finalmente ser graficada, siendo posible así observar la señal cardiaca en el monitor de un computador como un tren de pulsos. Cabe destacar que par...

  15. Sensitive enumeration of Listeria monocytogenes and other Listeria species in various naturally contaminated matrices using a membrane filtration method.

    Science.gov (United States)

    Barre, Léna; Brasseur, Emilie; Doux, Camille; Lombard, Bertrand; Besse, Nathalie Gnanou

    2015-06-01

    For the enumeration of Listeria monocytogenes (L. monocytogenes) in food, a sensitive enumeration method has been recently developed. This method is based on a membrane filtration of the food suspension followed by transfer of the filter on a selective medium to enumerate L. monocytogenes. An evaluation of this method was performed with several categories of foods naturally contaminated with L. monocytogenes. The results obtained with this technique were compared with those obtained from the modified reference EN ISO 11290-2 method for the enumeration of L. monocytogenes in food, and are found to provide more precise results. In most cases, the filtration method enabled to examine a greater quantity of food thus greatly improving the sensitivity of the enumeration. However, it was hardly applicable to some food categories because of filtration problems and background microbiota interference. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Anti-Listeria starters: in vitro selection and production plant evaluation.

    Science.gov (United States)

    Raimondi, Stefano; Popovic, Mina; Amaretti, Alberto; Di Gioia, Diana; Rossi, Maddalena

    2014-05-01

    Anti-Listeria bacterial starters are highly demanded by the meat industry. Novel bioprotective anti-Listeria starters were searched among Lactobacillus species strains isolated from artisanal sausages. The screening confirmed that anti-Listeria activity is a strain-specific property and yielded only 1 strain (of 36) exhibiting a satisfactory level of inhibition, L. delbrueckii WC0286. This strain was compared with two commercial bioprotective starters, SafePro B-SF-43 and SafePro B-LC-20, in a model simulating in vitro the first step of the fermentation process. The presence of the bioprotective starters did not modify the pH in such a way that could affect the safety or organoleptic properties of the product. Both SafePro B-SF-43 and SafePro B-LC-20 effected an important reduction of Listeria counts (0.56 and 0.72 log CFU g(-1), respectively, in 72 h), while the anti-Listeria effect of L. delbrueckii WC0286 was minor (0.15 log CFU g(-1)). These results discouraged the utilization of L. delbrueckii WC0286 for a challenge test in a pilot salami production, in favor of the best-performing bioprotective starter, SafePro B-LC-20. The test confirmed that SafePro B-LC-20 did not alter the acidification trend of sausages and was capable of inhibiting Listeria, which decreased by 1.21 log CFU g(-1). This information is relevant to address research activity toward the development of new bioprotective starters. The data herein presented demonstrate that the efficacy in Listeria control of potentially bioprotective bacterial starters requires further validation in real meat matrixes, possibly by using in vitro meat fermentation experiments to narrow down the list of candidates before pilot scale challenge tests.

  17. Prevalence of Listeria species in raw milk and traditional dairy products in Isfahan, Iran

    Directory of Open Access Journals (Sweden)

    Ehsan Shamloo

    2015-01-01

    Full Text Available Aim: The study aimed to assess the prevalence of Listeria spp. in raw milk and traditional non-pasteurized dairy products in Isfahan, Iran. Materials and Methods: A total of 292 samples of raw milk and traditional dairy were examined for the presence of Listeria spp. using a two-step selective enrichment recommended by the United States Department of Agriculture. All isolates were subjected to standard biochemical tests. L. monocytogenes strains were further confirmed by polymerase chain reaction (PCR amplification. Results: Of 292 samples, 21 (7.14% and 4 (1.47% were positive for Listeria spp. and pathogenic L. monocytogenes, respectively. The prevalence of Listeria spp. in raw milk, ice cream, cream, and freni were 5.91 (5.49%, 12.63 (19.04%, 3.27 (11.11% and 1.25 (4%, respectively. Listeria was not detected from yogurt, butter, Kashk, and cheese. Listeria innocua at 16.21 (5.44% was the most prevalent species isolated, followed by L. monocytogenes at 4.21 (19% and L. seeligeri at 1.21 (4.7%. All strains of L. monocytogenes identified by biochemical tests were also confirmed by PCR. Conclusion: The study shows the prevalence of L. monocytogenes in raw milk and traditional dairy products sold in the market. Consumption of raw milk with mild heat treatment or its usage in traditional dishes could pose serious health problems due to lack of appropriate control measures. The lack of knowledge on the risks of listeriosis transmission indicates the need for implementation of a food safety education program. In addition, the Iranian food safety authorities should urgently set up an effective standard to screen all susceptible food products for the presence of Listeria.

  18. Identification of listeria species isolated in Tunisia by Microarray based assay : results of a preliminary study

    International Nuclear Information System (INIS)

    Hmaied, Fatma; Helel, Salma; Barkallah, Insaf; Leberre, V.; Francois, J.M.; Kechrid, A.

    2008-01-01

    Microarray-based assay is a new molecular approach for genetic screening and identification of microorganisms. We have developed a rapid microarray-based assay for the reliable detection and discrimination of Listeria spp. in food and clinical isolates from Tunisia. The method used in the present study is based on the PCR amplification of a virulence factor gene (iap gene). the PCR mixture contained cyanine Cy5labeled dCTP. Therefore, The PCR products were fluorescently labeled. The presence of multiple species-specific sequences within the iap gene enabled us to design different oligoprobes per species. The species-specific sequences of the iap gene used in this study were obtained from genBank and then aligned for phylogenetic analysis in order to identify and retrieve the sequences of homologues of the amplified iap gene analysed. 20 probes were used for detection and identification of 22 food isolates and clinical isolates of Listeria spp (L. monocytogenes, L. ivanovi), L. welshimeri, L. seeligeri, and L. grayi). Each bacterial gene was identified by hybridization to oligoprobes specific for each Listeria species and immobilized on a glass surface. The microarray analysis showed that 5 clinical isolates and 2 food isolates were identified listeria monocytogenes. Concerning the remaining 15 food isolates; 13 were identified listeria innocua and 2 isolates could not be identified by microarray based assay. Further phylogenetic and molecular analysis are required to design more species-specific probes for the identification of Listeria spp. Microarray-based assay is a simple and rapid method used for Listeria species discrimination

  19. Detection of Antibiotic Resistant Listeria spp. in Beef Burgers Distributed in Ahvaz City, Iran

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    Maktabi

    2016-03-01

    Full Text Available Background Listeria spp. are able to be survive in many foods during frozen storage. One particular species, Listeria monocytogenes, is one of the most important food-borne pathogens globally. The antimicrobial resistance of pathogenic microorganisms is a worldwide public health concern because of increasing global trade and travel. Objectives The aim of this study was to evaluate the occurrence and antibiotic resistance of Listeria spp. in the Iranian beef burgers distributed in Ahvaz city. Materials and Methods During a five-month period, 150 frozen burgers were purchased from local markets in Ahvaz city, and tested for presence of Listeria spp. The experimental procedure consisted of a one-step enrichment in Listeria enrichment broth, followed by plating on Oxford agar. Suspected colonies were subjected to subsequent biochemical tests and a polymerase chain reaction (PCR assay. The susceptibility of the isolates to various antibiotics was investigated using the Kirby-Bauer disk diffusion method, and the results were analyzed via the chi-square test and Fisher’s exact test using SPSS 16.0 software. Results Out of 150 samples, only two were contaminated with Listeria innocua, and the statistical analysis showed no significant differences in the prevalence of Listeria between companies (P > 0.05. One of the isolates was resistant to tetracycline and the other to co-trimoxazole. Both of the isolates showed an intermediate susceptibility to chloramphenicol; however, they were sensitive to the other tested antibiotics. Conclusions L. innocua is not a pathogen, but the presence of the bacterium could be an indicator of probable contamination with L. monocytogenes. Moreover, there is a potential risk to public health from the consumption of raw or undercooked burgers, which may increase the possibility of the acquisition of resistance to antibiotics.

  20. Rapid colorimetric sensing platform for the detection of Listeria monocytogenes foodborne pathogen.

    Science.gov (United States)

    Alhogail, Sahar; Suaifan, Ghadeer A R Y; Zourob, Mohammed

    2016-12-15

    Listeria monocytogenes is a serious cause of human foodborne infections worldwide, which needs spending billions of dollars for inspection of bacterial contamination in food every year. Therefore, there is an urgent need for rapid, in-field and cost effective detection techniques. In this study, rapid, low-cost and simple colorimetric assay was developed using magnetic nanoparticles for the detection of listeria bacteria. The protease from the listeria bacteria was detected using D-amino acid substrate. D-amino acid substrate was linked to the carboxylic acid on the magnetic nanoparticles using EDC/NHS chemistry. The cysteine residue at the C-terminal of the substrate was used for the self-assembled monolayer formation on the gold sensor surface, which in turn the black magnetic nanobeads will mask the golden color. The color will change from black to golden color upon the cleavage of the specific peptide sequence by the Listeria protease. The sensor was tested with serial dilutions of Listeria bacteria. It was found that the appearance of the gold surface area is proportional to the bacterial concentrations in CFU/ml. The lowest detection limit of the developed sensor for Listeria was found to be 2.17×10(2) colony forming unit/ml (CFU/ml). The specificity of the biosensor was tested against four different foodborne associated bacteria (Escherichia coli, Salmonella, Shigella flexnerii and Staphylococcus aureus). Finally, the sensor was tested with artificially spiked whole milk and ground meat spiked with listeria. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Indice por Materias

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    Montoya H Luz Marina

    1982-09-01

    Full Text Available Un índice es una lista de palabras o frases indicadores asociados que permite la ubicación de material al interior de un libro o una publicación, en este caso será por el nombre de la materia.

  2. 9 CFR 430.4 - Control of Listeria monocytogenes in post-lethality exposed ready-to-eat products.

    Science.gov (United States)

    2010-01-01

    ... post-lethality exposed ready-to-eat products. 430.4 Section 430.4 Animals and Animal Products FOOD... Control of Listeria monocytogenes in post-lethality exposed ready-to-eat products. (a) Listeria... comes into direct contact with a food contact surface which is contaminated with L. monocytogenes. (b...

  3. Complete genome sequence of Listeria monocytogenes strain MR310, isolated from a pastured-flock poultry farm system

    Science.gov (United States)

    Investigation of Listeria monocytogenes transmission from environmental sources associated with pasture-raised chickens to poultry products is needed to determine ways to prevent potential foodborne illness. Here, we report the complete genome sequence of Listeria monocytogenes MR310, one of the iso...

  4. Frequency of contamination Listeria monocytogenes of raw dried cured vacuum packed sausages

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    Hristo Daskalov

    2014-03-01

    Full Text Available The aim of this study was to collect actual data concerning the frequency of contamination with Listeria monocytogenes of some very popular in Bulgaria raw dried cured vacuum packed sausages, produced from October 2004 till May 2008. 148 vacuum-packed samples were taken from 9 different food business operators during all seasons of the year. The samples were analyzed according to USDA method for meat foods. Ten specimens were positive for presence of Listeria monocytogenes equal to 6,75% of all tested samples. In two other raw dried cured sausages L.welshimeri and L.innocua were found, but these species are not pathogenic for consumers. In the period before the official implementation of HACCP system (01.01.2006 in Bulgaria, 52 samples were examined and 5 Listeria monocytogenes isolates were found (~10%. 2,5 years after the HACCP implementation, 96 specimens from the same meat factories were tested and 5 Listeria monocytogenes isolates (5,2% were detected. Samples taken from lots, produced in winter time were contaminated with Listeria monocytogenes more often (7 of all 10 than specimens taken during other seasons. Data were discussed through the point of view of the effectiveness of hygienic practices and HACCP system application. Also, application of ‘microbiological criterion’ set in COMMISSION REGULATION (EC No 2073/2005 for ready-to-eat foods unable to support the growth of L. monocytogenes was considered.

  5. Prevalence and antimicrobial resistance of Listeria, Salmonella, and Yersinia species isolates in ducks and geese.

    Science.gov (United States)

    Jamali, Hossein; Radmehr, Behrad; Ismail, Salmah

    2014-04-01

    The aims of this study were to determine the prevalence and antimicrobial resistance of Listeria, Salmonella, and Yersinia spp. isolated from duck and goose intestinal contents. A total of 471 samples, including 291 duck and 180 goose intestinal contents, were purchased from wet markets between November 2008 and July 2010. Listeria, Salmonella, and Yersinia spp. were isolated from 58 (12.3%), 107 (22.7%), and 80 (17%) of the samples, respectively. It was concluded that Listeria ivanovii, Salmonella Thompson, and Yersinia enterocolitica were the predominant serovars among Listeria, Salmonella, and Yersinia spp., respectively. Moreover, resistance to tetracycline was common in Listeria (48.3%) and Salmonella spp. (63.6%), whereas 51.3% of the Yersinia spp. isolates were resistant to cephalothin. Therefore, continued surveillance of the prevalence of the pathogens and also of emerging antibiotic resistance is needed to render possible the recognition of foods that may represent risks and also ensure the effective treatment of listeriosis, salmonellosis, and yersiniosis.

  6. Characterization and antibiotic susceptibility of Listeria monocytogenes isolated from poultry and red meat in Morocco

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    Hayat Ennaji

    2008-09-01

    Full Text Available Hayat Ennaji1,2, Mohammed Timinouni2, My Mustapha Ennaji3, Mohammed Hassar1, Nozha Cohen11Laboratoire de Microbiologie et Hygiène des Aliments et de l’Environnement, Institut Pasteur du Maroc., Casablanca, Morocco; 2Laboratoire de Microbiologie et Biologie Moléculaire, Institut Pasteur du Maroc., Casablanca, Morocco; 3Laboratoire de Virologie et Hygiène and Microbiologie., Faculté des Sciences et Techniques - Mohammedia, Université Hassan II, Mohammedia, MoroccoAbstract: This study was carried out on 426 samples of raw meats collected from butcheries and supermarkets in Casablanca, Morocco. The samples were examined for the occurrence of Listeria species. Strains of Listeria monocytogenes were characterized by several biochemical tests and confirmed by polymerase chain reaction (PCR. β-hemolytic cultures and nonhemolytic isolates were tested for biochemical properties with the Listeria API test. Among the 43 Listeria species isolates; we identified 10 strains for L. monocytogenes (23.3%, 31 strains for L. innocua (72.1% and 2 strains for L. welshimeri (4.6%. Strains of L. monocytogenes were separated by multiplex PCR; two serogroups IIb and IVb were thus differentiated. Antibiotic susceptibility of L. monocytogenes to 21 antibiotics was determined by the disk diffusion method. All isolates were susceptible to a wide range of the tested antibiotics with the exception of nalidixic acid, colistine and cephalosporins second and third generation for which they were all resistant.Keywords: antibiotic susceptibility, Listeria monocytogenes, meat, PCR

  7. Apendicitis por Paracoccidioides brasiliensis

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    Ana Beatriz MUÑOZ URRIBARRI

    2006-01-01

    Full Text Available La paracoccidioidomicosis es la micosis más prevalente en Sudamérica. La forma aguda afecta el sistema fagocítico mononuclear de niños y personas inmunocomprometidas. El compromiso gastrointestinal es frecuente y su patogenia implica diseminación hematógena y linfática. La linfadenomegalia abdominal causa obstrucción intestinal y abdomen agudo. En este artículo damos a conocer el caso de un niño con compromiso gastrointestinal por apendicitis. Este es el primer caso reportado de apendicitis por esta patología. (Rev Med Hered 2006;17:58-60.

  8. Listeria spp. in Street-Vended Ready-to-Eat Foods

    Science.gov (United States)

    El-Shenawy, Moustafa; El-Shenawy, Mohamed; Mañes, Jordi; Soriano, Jose M.

    2011-01-01

    Street-vended ready-to-eat food sold in Egypt, including sandwiches and dishes of traditional food, was examined for the presence of Listeria species. Out of 576 samples, 24% were found to contain Listeria species. L. monocytogenes and L. innocua were isolated from 57% and 39% of the contaminated samples, respectively. Other Listeria spp. were detected with lower frequency. L. monocytogenes of ≥103 CFU/g were detected in 7% of the total examined samples, which represent 49% of the contaminated food samples (meat, poultry, seafood, dairy products, and products of plant origin). Most of the samples contaminated by L. monocytogenes had high levels of total viable bacterial counts. The results obtained may help to clarify the epidemiology of listeriosis in the country and draw the attention of the decision makers to issue hygienic regulations for food processing industries as well as street vendors in order to ensure safe street-vended ready-to-eat food. PMID:22194742

  9. Use of vacuum-steam-vacuum and ionizing radiation to eliminate Listeria innocua from ham.

    Science.gov (United States)

    Sommers, Christopher; Kozempel, Michael; Fan, Xuetong; Radewonuk, E Richard

    2002-12-01

    Listeria spp. are a frequent postprocess contaminant of ready-to-eat (RTE) meat products, including ham. Vacuum-steam-vacuum (VSV) technology has been used successfully to eliminate Listeria innocua from hot dogs. Ionizing radiation can eliminate Listeria spp. from RTE meats. However, the excessive application of either technology can cause changes in product quality, including structural changes, changes in cure color (redness), and lipid oxidation. In this study, two cycles of VSV were combined with 2.0 kGy of ionizing radiation to obtain 4.40- and 4.85-log10 reductions of L. innocua on ham meat and skin, respectively. The use of both treatments resulted in an additive, as opposed to synergistic, reduction of L. innocua on ham. The combination treatment did not cause statistically significant changes in product structure, color (redness), or lipid oxidation.

  10. Wild birds and silage as reservoirs of Listeria in the agricultural environment.

    Science.gov (United States)

    Fenlon, D R

    1985-12-01

    A method for the isolation of listeria which enabled a more rapid detection of the organism was used to examine samples of silage and bird faeces. Faecal samples indicated that seagulls feeding at sewage works had a higher rate of carriage than those elsewhere. Faecal samples from rooks generally suggested a low incidence of listeria except on one occasion when eight of twenty samples contained Listeria monocytogenes: this coincided with the nesting season and the peak period for listeriosis in sheep. The incidence of L. monocytogenes in clamp silages ranged from 2.5-5.9%, but in samples of big bale silages the incidence was 22.2% and, when mouldy samples were selected, 44%.

  11. Frequency, virulence genes and antimicrobial resistance of Listeria spp. isolated from bovine clinical mastitis.

    Science.gov (United States)

    Jamali, Hossein; Radmehr, Behrad

    2013-11-01

    The aims of this study were to determine the prevalence, characteristics and antimicrobial resistance of Listeria spp. isolated from bovine clinical mastitis in Iran. Listeria spp. were detected in 21/207 bovine mastitic milk samples from dairy farms in Iran, comprising L. monocytogenes (n=17), L. innocua (n=3) and L. ivanovii (n=1). L. monocytogenes isolates were grouped into serogroups '4b, 4d, 4e', '1/2a, 3a', '1/2b, 3b, 7' and '1/2c, 3c'; all harboured inlA, inlC and inlJ virulence genes. Listeria spp. were most frequently resistant to penicillin G (14/21 isolates, 66.7%) and tetracyclines (11/21 isolates, 52.4%). Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. The effect of centaurein on interferon-γ expression and Listeria infection in mice

    International Nuclear Information System (INIS)

    Chang, S.-L.; Yeh, H.-H.; Lin, Y.-S.; Chiang, Y.-M.; Wu, T.-K.; Yang, W.-C.

    2007-01-01

    We previously found that centaurein enhanced IFN-γ transcription in T cells. Here, we demonstrate that centaurein increased the IFN-γ expression in T and NK cells and the serum IFN-γ level in mice. Centaurein elevated the transcription of T-bet but not GATA-3, which is consistent with its effect on that of IFN-γ but not IL-4. Additionally, centaurein effectively protected mice against Listeria infection. Moreover, centaurein per se or in combination with antibiotics could treat Listeria infection. Our mechanistic studies suggest that centaurein augments IFN-γ expression via a transcriptional up-regulation of T-bet and that centaurein protects against or treats Listeria infection via a modulation of IFN-γ expression

  13. Genetic characteristics of Japanese clinical Listeria monocytogenes isolates.

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    Satoko Miya

    Full Text Available Listeria monocytogenes causes foodborne illnesses through consumption of ready-to-eat foods. Although 135-201annual listeriosis cases have been estimated in Japan, the details regarding the clinical isolates such as infection source, virulence level, and other genetic characteristics, are not known. In order to uncover the trends of listeriosis in Japan and use the knowledge for prevention measures to be taken, the genetic characteristics of the past human clinical isolates needs to be elucidated. For this purpose, multilocus tandem-repeat sequence analysis (MLTSA and multi-virulence-locus sequence typing (MVLST were used in this study. The clinical isolates showed a variety of genetically distant genotypes, indicating they were from sporadic cases. However, the MVLST profiles of 7 clinical isolates were identical to those of epidemic clone (EC I isolates, which have caused several serious outbreaks in other countries, suggesting the possibility that they have strong virulence potential and originated from a single outbreak. Moreover, 6 Japanese food isolates shared their genotypes with ECI isolates, indicating that there may be risks for listeriosis outbreak in Japan. This is the first investigational study on genetic characteristics of Japanese listeriosis isolates. The listeriosis cases happened in the past are presumably sporadic, but it is still possible that some isolates with strong virulence potential have caused listeriosis outbreaks, and future listeriosis risks also exist.

  14. Flagellar motility is critical for Listeria monocytogenes biofilm formation.

    Science.gov (United States)

    Lemon, Katherine P; Higgins, Darren E; Kolter, Roberto

    2007-06-01

    The food-borne pathogen Listeria monocytogenes attaches to environmental surfaces and forms biofilms that can be a source of food contamination, yet little is known about the molecular mechanisms of its biofilm development. We observed that nonmotile mutants were defective in biofilm formation. To investigate how flagella might function during biofilm formation, we compared the wild type with flagellum-minus and paralyzed-flagellum mutants. Both nonmotile mutants were defective in biofilm development, presumably at an early stage, as they were also defective in attachment to glass during the first few hours of surface exposure. This attachment defect could be significantly overcome by providing exogenous movement toward the surface via centrifugation. However, this centrifugation did not restore mature biofilm formation. Our results indicate that it is flagellum-mediated motility that is critical for both initial surface attachment and subsequent biofilm formation. Also, any role for L. monocytogenes flagella as adhesins on abiotic surfaces appears to be either minimal or motility dependent under the conditions we examined.

  15. LISTERIA MONOCYTOGENES RISK EVALUATION IN READY TO EAT DELI PRODUCTS

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    T Civera

    2013-02-01

    Full Text Available Listeria monocytogenes has become one of the major concerns for food safety. Its ability to survive and replicate at low temperature, pH and high salt concentration, makes the bacterium a threat, mostly for RTE products. For these reasons, the present research was aimed at detecting the ability of growth of L. monocytogenes in RTE products retrieved from one deli store. Samples were analysed for L. monocytogenes detection, then inoculated with the pathogen (105cell/ml and stored at refrigeration temperature for the duration of their shelf-life (15-60 days. In all the products L. monocytogenes was not detected before experimental contamination. The challenge test evidenced that experimentally inoculated L. monocytogenes was not able to multiply for the duration of the entire shelf-life. These results indicated that the tested products could be considered as foods which are not able to support the growth of L. monocytogenes, as indicated by E.C. Regulation 2073/05. However, in order to guarantee consumer’s safety, it needs to be emphasized the need of a correct application of the GMPs, required for lowering the risk of initial contamination.

  16. Listeria monocytogenes serotype prevalence and biodiversity in diverse food products.

    Science.gov (United States)

    Hadjilouka, Agni; Andritsos, Nikolaos D; Paramithiotis, Spiros; Mataragas, Marios; Drosinos, Eleftherios H

    2014-12-01

    The aim of this study was to assess serotype prevalence and biodiversity of Listeria monocytogenes strains isolated from diverse food products, i.e., minced pork, fruits, and vegetables. Three hundred twenty-six samples previously purchased from supermarkets and street markets within the Athens area were studied for L. monocytogenes prevalence. A total of 121 strains were isolated from the 36 samples that were positive for L. monocytogenes. Serotyping was performed with multiplex PCR, and biodiversity was assessed with random amplified polymorphic DNA (RAPD) PCR analysis using M13, UBC155, and HLWL85 as primers and with repetitive element palindromic (rep) PCR analysis using (GTG)5 as the primer. The majority (17 of 22) of the contaminated minced pork samples contained strains identified as serotype 1/2a, either alone or in combination with strains belonging to serotypes 1/2b, 4a, 4c, or 4ab. However, all L. monocytogenes isolates from fruits and vegetables belonged to serotype 4b. Rep-PCR provided better differentiation of the isolates than did RAPD PCR and resulted in discrimination of the isolates into a larger number of unique profiles. Complete differentiation was achieved only with the combination of these subtyping techniques.

  17. Low prevalence of Listeria monocytogenes in cull sows and pork.

    Science.gov (United States)

    Wesley, Irene V; Larsen, Steven; Hurd, H Scott; McKean, James D; Griffith, Ronald; Rivera, Fernando; Nannapaneni, Ramakrishna; Cox, Mandy; Johnson, Michael; Wagner, Dean; de Martino, Mary

    2008-03-01

    The goal of this study was to determine the prevalence of Listeria monocytogenes in sows slaughtered at a single Midwestern plant on two occasions (trial 1, n = 179 sows; trial 2, n = 160 sows). Fecal samples collected antemortem (trial 1) as well as animal tissues, and carcass swabs collected at the abattoir (trials 1 and 2) were analyzed. Eight isolates of L. monocytogenes were recovered from five samples that represented 0.18% of the total samples (n = 2,775). In trial 1, L. monocytogenes was detected in a tonsil sample (0.6%; 1 positive of 181 tonsils), in a carcass (0.6%; 1 positive of 179 carcasses), which was sampled prior to the organic rinse, and in two chopped meat block samples (1.2%; 2 positive of 165 samples). In trial 2, L. monocytogenes was only detected in a single chopped meat block sample (0.15%; 1 positive of 688 total samples). These data indicate the low prevalence of L. monocytogenes in the cull sow.

  18. ASSESSMENT OF ACTION OF DISINFECTANTS AGAINST LISTERIA MONOCYTOGENES BIOFILMS

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    T. K. CABEÇA

    2008-12-01

    Full Text Available

    The purpose of this study was to assess the action of various disinfectants used in food industry against biofilm cells of Listeria monocytogenes formed on stainless steel surfaces during 24, 72 and 120 hours. Numbers of viable biofilm cells decreased after treatment with all the tested disinfectants (iodine, biguanide, quaternary ammonium compounds, peracetic acid and sodium hypochlorite. Sodium hypochlorite was the most effective disinfectant against the biofilm cells, while biguanide and iodine were the least. Scanning electron microscopy observations demonstrated attached cells on stainless steel surfaces after treatment with all the disinfectants. These observations showed that microorganisms were not completely removed from stainless steel surfaces after treatment with the disinfectants, however, the attachment did not means the viability of remaining cells. The biofilm age in hours (24, 72 and 120 had no apparent influence on resistance of microbiological cells to the disinfectants under study. In conclusion biofilm cells of L. monocytogenes can withstand disinfectants action.

  19. Listeria monocytogenes, a down-to-earth pathogen.

    Science.gov (United States)

    Vivant, Anne-Laure; Garmyn, Dominique; Piveteau, Pascal

    2013-01-01

    Listeria monocytogenes is the causative agent of the food-borne life threatening disease listeriosis. This pathogenic bacterium received much attention in the endeavor of deciphering the cellular mechanisms that underlie the onset of infection and its ability to adapt to the food processing environment. Although information is available on the presence of L. monocytogenes in many environmental niches including soil, water, plants, foodstuff and animals, understanding the ecology of L. monocytogenes in outdoor environments has received less attention. Soil is an environmental niche of pivotal importance in the transmission of this bacterium to plants and animals. Soil composition, microbial communities and macrofauna are extrinsic edaphic factors that direct the fate of L. monocytogenes in the soil environment. Moreover, farming practices may further affect its incidence. The genome of L. monocytogenes presents an extensive repertoire of genes encoding transport proteins and regulators, a characteristic of the genome of ubiquitous bacteria. Postgenomic analyses bring new insights in the process of soil adaptation. In the present paper focussing on soil, we review these extrinsic and intrinsic factors that drive environmental adaptation of L. monocytogenes.

  20. Biofilm Formation of Listeria monocytogenes on Various Surfaces

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    M Mahdavi

    2007-10-01

    Full Text Available Introduction & Objective: Listeria monocytogenes is considered as a ubiquitous foodborne pathogen which can lead to serious infections, especially in newborns, elderly, pregnant, and immunocompromised people. The organism has been isolated from many foods and may cause meningitis, septicemia and abortion in pregnant women. Also L. monocytogenes forms biofilms on many food contact surface materials and medical devices. Development of biofilms on many surfaces is a potential source of contamination of foods that may lead to spoilage or transmission of foodborne pathogens. Materials & Methods: Biofilm formation of L. monocytogenes (RITCC 1293 serotype 4a was investigated. Hydrophobicity of L. monocytogenes was measured by MATH method. Then biofilm formation of the organism was assessed at 2, 4, 8, 16 and 20 hours on stainless steel (type 304 no 2B, polyethylene and glass by drop plate method. Results: Results indicated that L. monocytogenes with 85% of hydrophobicity formed biofilm on each of three surfaces. Biofilm formation on stainless steel surfaces was significantly more than other surfaces (p<0.05. Conclusion: The ability of biofilm formation of L. monocytogenes on medical devices and food containers is very important as far as hygiene and disease outbreaks are concerned.

  1. Inhibition of sortase A by chalcone prevents Listeria monocytogenes infection.

    Science.gov (United States)

    Li, Hongen; Chen, Yutao; Zhang, Bing; Niu, Xiaodi; Song, Meng; Luo, Zhaoqing; Lu, Gejin; Liu, Bowen; Zhao, Xiaoran; Wang, Jianfeng; Deng, Xuming

    2016-04-15

    The critical role of sortase A in gram-positive bacterial pathogenicity makes this protein a good potential target for antimicrobial therapy. In this study, we report for the first time the crystal structure of Listeria monocytogenes sortase A and identify the active sites that mediate its transpeptidase activity. We also used a sortase A (SrtA) enzyme activity inhibition assay, simulation, and isothermal titration calorimetry analysis to discover that chalcone, an agent with little anti-L. monocytogenes activity, could significantly inhibit sortase A activity with an IC50 of 28.41 ± 5.34 μM by occupying the active site of SrtA. The addition of chalcone to a co-culture of L. monocytogenes and Caco-2 cells significantly inhibited bacterial entry into the cells and L. monocytogenes-mediated cytotoxicity. Additionally, chalcone treatment decreased the mortality of infected mice, the bacterial burden in target organs, and the pathological damage to L. monocytogenes-infected mice. In conclusion, these findings suggest that chalcone is a promising candidate for the development of treatment against L. monocytogenes infection. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Deciphering the landscape of host barriers to Listeria monocytogenes infection.

    Science.gov (United States)

    Zhang, Ting; Abel, Sören; Abel Zur Wiesch, Pia; Sasabe, Jumpei; Davis, Brigid M; Higgins, Darren E; Waldor, Matthew K

    2017-06-13

    Listeria monocytogenes is a common food-borne pathogen that can disseminate from the intestine and infect multiple organs. Here, we used sequence tag-based analysis of microbial populations (STAMP) to investigate L monocytogenes population dynamics during infection. We created a genetically barcoded library of murinized L monocytogenes and then used deep sequencing to track the pathogen's dissemination routes and quantify its founding population ( N b ) sizes in different organs. We found that the pathogen disseminates from the gastrointestinal tract to distal sites through multiple independent routes and that N b sizes vary greatly among tissues, indicative of diverse host barriers to infection. Unexpectedly, comparative analyses of sequence tags revealed that fecally excreted organisms are largely derived from the very small number of L. monocytogenes cells that colonize the gallbladder. Immune depletion studies suggest that distinct innate immune cells restrict the pathogen's capacity to establish replicative niches in the spleen and liver. Finally, studies in germ-free mice suggest that the microbiota plays a critical role in the development of the splenic, but not the hepatic, barriers that prevent L. monocytogenes from seeding these organs. Collectively, these observations illustrate the potency of the STAMP approach to decipher the impact of host factors on population dynamics of pathogens during infection.

  3. A case of bovine raw milk contamination with Listeria monocytogenes

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    Hunt Karen

    2012-07-01

    Full Text Available Abstract During routine sampling of bulk raw milk on a dairy farm, the pathogenic bacteria Listeria monocytogenes was found to be a contaminant, at numbers L. monocytogenes, indicating a possible case of excretion of the L. monocytogenes directly into the milk. Milk samples were collected from the individual cows and analysed, resulting in the identification of L. monocytogenes excretion (at 280 cfu/ml from one of the 4 mammary quarters of one dairy cow out of 180. When the infected cow was isolated from the herd, no L. monocytogenes was detected from the remaining herd. The pulsed-field gel electrophoresis pattern of the strain from the individual cow was indistinguishable from that originally isolated from the bulk milk. The infected cow did not show any clinical signs of disease, nor did the appearance of the milk have any physical abnormalities. Antibiotic treatment of the infected mammary quarter was found to be ineffective. This study shows that there can be risks associated with direct contamination of raw milk with L. monocytogenes.

  4. Biotechnical paving of recombinant enterocin A as the candidate of anti-Listeria agent.

    Science.gov (United States)

    Hu, Xiaoyuan; Mao, Ruoyu; Zhang, Yong; Teng, Da; Wang, Xiumin; Xi, Di; Huang, Jianzhong; Wang, Jianhua

    2014-08-28

    Enterocin A is a classic IIa bacteriocin isolated firstly from Enterococcus faecium CTC492 with selective antimicrobial activity against Listeria strains. However, the application of enterocin A as an anti-Listeria agent has been limited due to its very low native yield. The present work describes high production of enterocin A through codon optimization strategy and its character study. The gene sequence of enterocin A was optimized based on preferential codon usage in Pichia pastoris to increase its expression efficiency. The highest anti-Listeria activity reached 51,200 AU/ml from 180 mg/l of total protein after 24 h of induction in a 5-L fermenter. Recombinant enterocin A (rEntA), purified by gel filtration chromatography, showed very strong activity against Listeria ivanovii ATCC 19119 with a low MIC of 20 ng/ml. In addition, the rEntA killed over 99% of tested L. ivanovii ATCC19119 within 4 h when exposed to 4 × MIC (80 ng/ml). Moreover, it showed high stability under a wide pH range (2-10) and maintained full activity after 1 h of treatment at 80°C within a pH range of 2-8. Its antimicrobial activity was enhanced at 25 and 50 mM NaCl, while 100-400 mM NaCl had little effect on the bactericidal ability of rEntA. The EntA was successfully expressed in P. pastoris, and this feasible system could pave the pre-industrial technological path of rEntA as a competent candidate as an anti-Listeria agent. Furthermore, it showed high stability under wide ranges of conditions, which could be potential as the new candidate of anti-Listeria agent.

  5. In vivo transcriptional profiling of Listeria monocytogenes and mutagenesis identify new virulence factors involved in infection.

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    Ana Camejo

    2009-05-01

    Full Text Available Listeria monocytogenes is a human intracellular pathogen able to colonize host tissues after ingestion of contaminated food, causing severe invasive infections. In order to gain a better understanding of the nature of host-pathogen interactions, we studied the L. monocytogenes genome expression during mouse infection. In the spleen of infected mice, approximately 20% of the Listeria genome is differentially expressed, essentially through gene activation, as compared to exponential growth in rich broth medium. Data presented here show that, during infection, Listeria is in an active multiplication phase, as revealed by the high expression of genes involved in replication, cell division and multiplication. In vivo bacterial growth requires increased expression of genes involved in adaptation of the bacterial metabolism and stress responses, in particular to oxidative stress. Listeria interaction with its host induces cell wall metabolism and surface expression of virulence factors. During infection, L. monocytogenes also activates subversion mechanisms of host defenses, including resistance to cationic peptides, peptidoglycan modifications and release of muramyl peptides. We show that the in vivo differential expression of the Listeria genome is coordinated by a complex regulatory network, with a central role for the PrfA-SigB interplay. In particular, L. monocytogenes up regulates in vivo the two major virulence regulators, PrfA and VirR, and their downstream effectors. Mutagenesis of in vivo induced genes allowed the identification of novel L. monocytogenes virulence factors, including an LPXTG surface protein, suggesting a role for S-layer glycoproteins and for cadmium efflux system in Listeria virulence.

  6. Evaluation of the Thermo Scientific™ SureTect™ Listeria species Assay.

    Science.gov (United States)

    Cloke, Jonathan; Evans, Katharine; Crabtree, David; Hughes, Annette; Simpson, Helen; Holopainen, Jani; Wickstrand, Nina; Kauppinen, Mikko

    2014-03-01

    The Thermo Scientific™ SureTect™ Listeria species Assay is a new real-time PCR assay for the detection of all species of Listeria in food and environmental samples. This validation study was conducted using the AOAC Research Institute (RI) Performance Tested MethodsSM program to validate the SureTect Listeria species Assay in comparison to the reference method detailed in International Organization for Standardization 11290-1:1996 including amendment 1:2004 in a variety of foods plus plastic and stainless steel. The food matrixes validated were smoked salmon, processed cheese, fresh bagged spinach, cantaloupe, cooked prawns, cooked sliced turkey meat, cooked sliced ham, salami, pork frankfurters, and raw ground beef. All matrixes were tested by Thermo Fisher Scientific, Microbiology Division, Basingstoke, UK. In addition, three matrixes (pork frankfurters, fresh bagged spinach, and stainless steel surface samples) were analyzed independently as part of the AOAC-RI-controlled independent laboratory study by the University of Guelph, Canada. Using probability of detection statistical analysis, a significant difference in favour of the SureTect assay was demonstrated between the SureTect and reference method for high level spiked samples of pork frankfurters, smoked salmon, cooked prawns, stainless steel, and low-spiked samples of salami. For all other matrixes, no significant difference was seen between the two methods during the study. Inclusivity testing was conducted with 68 different isolates of Listeria species, all of which were detected by the SureTect Listeria species Assay. None of the 33 exclusivity isolates were detected by the SureTect Listeria species Assay. Ruggedness testing was conducted to evaluate the performance of the assay with specific method deviations outside of the recommended parameters open to variation, which demonstrated that the assay gave reliable performance. Accelerated stability testing was additionally conducted, validating the

  7. Evaluation of the Thermo Scientific SureTect Listeria species assay. AOAC Performance Tested Method 071304.

    Science.gov (United States)

    Cloke, Jonathan; Evans, Katharine; Crabtree, David; Hughes, Annette; Simpson, Helen; Holopainen, Jani; Wickstrand, Nina; Kauppinen, Mikko; Leon-Velarde, Carlos; Larson, Nathan; Dave, Keron

    2014-01-01

    The Thermo Scientific SureTect Listeria species Assay is a new real-time PCR assay for the detection of all species of Listeria in food and environmental samples. This validation study was conducted using the AOAC Research Institute (RI) Performance Tested Methods program to validate the SureTect Listeria species Assay in comparison to the reference method detailed in International Organization for Standardization 11290-1:1996 including amendment 1:2004 in a variety of foods plus plastic and stainless steel. The food matrixes validated were smoked salmon, processed cheese, fresh bagged spinach, cantaloupe, cooked prawns, cooked sliced turkey meat, cooked sliced ham, salami, pork frankfurters, and raw ground beef. All matrixes were tested by Thermo Fisher Scientific, Microbiology Division, Basingstoke, UK. In addition, three matrixes (pork frankfurters, fresh bagged spinach, and stainless steel surface samples) were analyzed independently as part of the AOAC-RI-controlled independent laboratory study by the University ofGuelph, Canada. Using probability of detection statistical analysis, a significant difference in favour of the SureTect assay was demonstrated between the SureTect and reference method for high level spiked samples of pork frankfurters, smoked salmon, cooked prawns, stainless steel, and low-spiked samples of salami. For all other matrixes, no significant difference was seen between the two methods during the study. Inclusivity testing was conducted with 68 different isolates of Listeria species, all of which were detected by the SureTect Listeria species Assay. None of the 33 exclusivity isolates were detected by the SureTect Listeria species Assay. Ruggedness testing was conducted to evaluate the performance of the assay with specific method deviations outside of the recommended parameters open to variation, which demonstrated that the assay gave reliable performance. Accelerated stability testing was additionally conducted, validating the assay

  8. Host resistance of CD18 knockout mice against systemic infection with Listeria monocytogenes

    Science.gov (United States)

    Wu, Huaizhu; Prince, Joseph E.; Brayton, Cory F.; Shah, Chirayu; Zeve, Daniel; Gregory, Stephen H.; Smith, C. Wayne; Ballantyne, Christie M.

    2003-01-01

    Mice with targeted mutations of CD18, the common beta2 subunit of CD11/CD18 integrins, have leukocytosis, impaired transendothelial neutrophil emigration, and reduced host defense to Streptococcus pneumoniae, a gram-positive extracellular bacterium. Previous studies using blocking monoclonal antibodies suggested roles for CD18 and CD11b in hepatic neutrophil recruitment and host innate response to Listeria monocytogenes, a gram-positive intracellular bacterium. We induced systemic listeriosis in CD18 knockout (CD18-ko) and wild-type (WT) mice by tail vein injection with Listeria. By 14 days postinjection (dpi), 8 of 10 WT mice died, compared with 2 of 10 CD18-ko mice (P Listeria organisms in livers and spleens were similar in both groups at 20 min postinfection. By 3, 5, and 7 dpi, however, numbers of Listeria organisms were significantly lower in livers and spleens of CD18-ko mice than in WT mice. Histopathology showed that following Listeria infection, CD18-ko mice had milder inflammatory and necrotizing lesions in both spleens and livers than did WT mice. Cytokine assays indicated that baseline interleukin-1beta and granulocyte colony-stimulating factor (G-CSF) levels were higher in CD18-ko mice than in WT mice and that CD18-ko splenocytes produced higher levels of interleukin-1beta and G-CSF than WT splenocytes under the same amount of Listeria stimulation. These findings show that CD18 is not an absolute requirement for antilisterial innate immunity or hepatic neutrophil recruitment. We propose that the absence of CD18 in the mice results in the priming of innate immunity, as evidenced by elevated cytokine expression, and neutrophilic leukocytosis, which augments antilisterial defense.

  9. Listeria arpJ gene modifies T helper type 2 subset differentiation.

    Science.gov (United States)

    Kanoh, Makoto; Maruyama, Saho; Shen, Hua; Matsumoto, Akira; Shinomiya, Hiroto; Przybilla, Karin; Gouin, Edith; Cossart, Pascale; Goebel, Werner; Asano, Yoshihiro

    2015-07-15

    Although the T-cell subset differentiation pathway has been characterized extensively from the view of host gene regulation, the effects of genes of the pathogen on T-cell subset differentiation during infection have yet to be elucidated. Especially, the bacterial genes that are responsible for this shift have not yet been determined. Utilizing a single-gene-mutation Listeria panel, we investigated genes involved in the host-pathogen interaction that are required for the initiation of T-cell subset differentiation in the early phase of pathogen infection. We demonstrate that the induction of T helper types 1 and 2 (Th1 and Th2) subsets are separate phenomena and are mediated by distinct Listeria genes. We identified several candidate Listeria genes that appear to be involved in the host-Listeria interaction. Among them, arpJ is the strongest candidate gene for inhibiting Th2 subset induction. Furthermore, the analysis utilizing arpJ-deficient Listeria monocytogenes (Lm) revealed that the tumor necrosis factor (TNF) superfamily (Tnfsf) 9-TNF receptor superfamily (Tnfrsf) 9 interaction inhibits the Th2 response during Lm infection. arpJ is the candidate gene for inhibiting Th2 T-cell subset induction. The arpJ gene product influences the expression of Tnfsf/Tnfrsf on antigen-presenting cells and inhibits the Th2 T-cell subset differentiation during Listeria infection. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. Apendicitis por Paracoccidioides brasiliensis.

    OpenAIRE

    MUÑOZ URRIBARRI, Ana Beatriz; CHAPARRO DAMMERT, Eduardo; FERRUFINO LLACH, Juan Carlos; VASQUEZ FLORES, Luciola

    2012-01-01

    La paracoccidioidomicosis es la micosis más prevalente en Sudamérica. La forma aguda afecta el sistema fagocítico mononuclear de niños y personas inmunocomprometidas. El compromiso gastrointestinal es frecuente y su patogenia implica diseminación hematógena y linfática. La linfadenomegalia abdominal causa obstrucción intestinal y abdomen agudo. En este artículo damos a conocer el caso de un niño con compromiso gastrointestinal por apendicitis. Este es el primer caso reportado de apendicitis p...

  11. Meningitis por Streptococcus suis

    OpenAIRE

    Geffner Sclarsky, D. E.; Moreno Muñoz, R.; Campillo Alpera, Mª.S.; Pardo Serrano, F.J.; Gómez Gómez, A.; Martínez-Lozano, Mª.D.

    2001-01-01

    La infección humana por Streptococcus suis (S. suis) es una zoonosis, con un riesgo ocupacional conocido y que suele presentarse como meningitis purulenta, que tiene baja mortalidad y frecuentes secuelas de hipoacusia y ataxia. Se han publicado menos de 150 casos humanos desde el informe original de hace 30 años. Hay una reconocida distribución geográfica viviendo la mayoría de los afectados en el norte de Europa y el sudeste Asiático. En España se han comunicado dos pacientes con enfermedad ...

  12. Por mil devaluados pesos

    Directory of Open Access Journals (Sweden)

    Annie Rodríguez Collázos

    2013-03-01

    Full Text Available El estudio de lo popular y lo urbano hasta ahora se ha centrado en el comportamiento y en algunas relaciones de los habitantes con su entorno. “Por mil devaluados pesos. Publicidad popular y urbana”, pretende explorar las formas de publicidad, dispersas en diferentes espacios populares y urbanos en Bogotá, identificando esquemas y formas características de sus propios códigos comunicativos; se centran en un objeto de estudio consistente en las estrategias publicitarias y los códigos comunicativos en los mensajes publicitarios populares en las subculturas de San Victorino, 7 de Agosto y Sanandresito de San José.

  13. Prevalence and Antibiotic Resistance of Listeria Spp. Isolated from Ready-to-Eat Foods in Ankara

    OpenAIRE

    ŞİRELİ, Ufuk Tansel; GÜCÜKOĞLU, Ali

    2014-01-01

    In this study the presence of Listeria spp. is tested in 100 ready-to-eat food samples purchased from different stores and traditional food shops in the province of Ankara. The tested materials were 20 each of the following: mayonnaise based salad, kadınbudu köfte (fried meatball), fried liver, rice stuffed mussel, and green salad. Microbiological analyzes showed that 13 of 100 salad samples (13%) were contaminated with Listeria spp. while 10 of 100 salad samples (10%) were contaminated with ...

  14. Rol de la Tropomiosina y del Adaptador NEDD9 durante la invasión celular de Listeria Mnocytogenes

    Directory of Open Access Journals (Sweden)

    Kattia Núñez-Montero

    2014-12-01

    Full Text Available Listeria monocytogenes es un patógeno de animales y humanos que logra invadir el espacio intracelular gracias a la interacción entre proteínas bacterianas de superficie y receptores en células hospedero, lo que permite activar cascadas de señalización que promueven la internalización de esta bacteria. El silenciamiento de la expresión génica en células de mamífero gracias a la técnica de transfección de ARNs pequeños de interferencia (siARN ha permitido recientemente asociar nuevos efectores moleculares al proceso de internalización de distintos patógenos intracelulares en células eucariotas. Esta investigación hace uso de esta técnica para determinar la posible contribución de la tropomiosina (TPM y de la proteína adaptadora NEDD9 a la invasión celular por parte de L. monocytogenes, así como de Salmonella typhimurium y de una cepa de Escherichia coli que expresa la invasina de Yersinia pseudotuberculosis. Utilizando ensayos de invasión se demuestra que el silenciamiento de la expresión de TPM, pero no de NEDD9, reduce significativamente la entrada de los tres patógenos intracelulares estudiados. Mediante microscopía de fluorescencia se observa que el silenciamiento de TPM y NEDD9 afecta en forma diferente la morfología celular y la distribución de los filamentos de actina. Estos resultados sugieren que TPM puede modular la entrada de patógenos bacterianos mediante una modificación de las propiedades de reorganización de la membrana plasmática dependientes del citoesqueleto de actina, propiedades que difieren de aquellas afectadas por NEDD9.

  15. Antimicrobial susceptibilities of Listeria monocytogenes human strains isolated from 1970 to 2008 in Brazil Susceptibilidade antimicrobiana de cepas humanas de Listeria monocytogenes isoladas no período de 1970 a 2008 no Brasil

    Directory of Open Access Journals (Sweden)

    Cristhiane Moura Falavina dos Reis

    2011-04-01

    Full Text Available INTRODUCTION: Listeria monocytogenes is the causative agent of listeriosis, a foodborne illness that affects mainly pregnant women, the elderly and immunocompromised patients. The primary treatment is a combination of ampicillin with an aminoglycoside, in addition to a second-choice drug represented by chloramphenicol, erythromycin, tetracycline and rifampicin. The aim of this study was to analyze the antimicrobial susceptibility profile of strains isolated from human sources in the last four decades. METHODS: Sixty-eight strains were selected from the culture collection of the Laboratory of Bacterial Zoonoses/LABZOO/FIOCRUZ isolated in different regions of Brazil from 1970 to 2008 and primarily isolated from cerebrospinal fluid and blood culture. Susceptibility tests to antimicrobials drugs were evaluated using the criteria established by Soussy using the Kirby-Bauer method and E-Test strips were used to determine the minimum inhibitory concentration (MIC. RESULTS: Among the strains tested, serovar L4b (60.3% was the most prevalent, followed by serovar 1/2a (20.6%, 1/2b (13.2% and the more uncommon serovars 1/2c, 3b and 4ab (5.9%. All strains were susceptible to ampicillin, cephalothin, erythromycin, gentamicin, teicoplanin and vancomycin. Only one strain (1.5% showed resistance to rifampin, and two (3% were resistant to trimethoprim-sulfamethoxazole. MICs with values up to 2μg/ml reinforce the need for microbiological surveillance. CONCLUSIONS: The study demonstrated low prevalence of strains resistant to the antimicrobial drugs indicated in the treatment of human listeriosis. Monitoring antimicrobial resistance profile is still very important to determine adequate treatment, especially in immunocompromised patients.INTRODUÇÃO: Listeria monocytogenes é o agente etiológico da listeriose, doença de origem alimentar que acomete principalmente grávidas, pacientes imunodeprimidos e idosos. O tratamento primário é a associação de

  16. Sepsis por shigella flexneri

    Directory of Open Access Journals (Sweden)

    César Cabrera C

    2005-04-01

    Full Text Available Se presenta un caso raro de sepsis por Shigella flexneri en una paciente de 45 años de edad quien estando hospitalizada para el estudio de un tumor cerebral, requirió el uso de manitol y dosis altas de corticoides; luego de ello presenta deposiciones líquidas con moco y sangre, desarrolla síndrome de respuesta inflamatoria sistémica, luego se aísla Shigella flexneri en el hemocultivo; recibió tratamiento antibiótico con ciprofloxacina. Se describen las características del caso y se comenta de acuerdo con la revisión de literatura.

  17. The Effect of Oxygen on Bile Resistance in Listeria monocytogenes

    Science.gov (United States)

    Wright, Morgan L; Pendarvis, Ken; Nanduri, Bindu; Edelmann, Mariola J; Jenkins, Haley N; Reddy, Joseph S; Wilson, Jessica G; Ding, Xuan; Broadway, Paul R; Ammari, Mais G; Paul, Oindrila; Roberts, Brandy; Donaldson, Janet R

    2016-01-01

    Listeria monocytogenes is a Gram-positive facultative anaerobe that is the causative agent of the disease listeriosis. The infectious ability of this bacterium is dependent upon resistance to stressors encountered within the gastrointestinal tract, including bile. Previous studies have indicated bile salt hydrolase activity increases under anaerobic conditions, suggesting anaerobic conditions influence stress responses. Therefore, the goal of this study was to determine if reduced oxygen availability increased bile resistance of L. monocytogenes. Four strains representing three serovars were evaluated for changes in viability and proteome expression following exposure to bile in aerobic or anaerobic conditions. Viability for F2365 (serovar 4b), EGD-e (serovar 1/2a), and 10403S (serovar 1/2a) increased following exposure to 10% porcine bile under anaerobic conditions (P 0.05) in bile resistance between aerobic and anaerobic conditions, indicating that oxygen availability does not influence resistance in this strain. The proteomic analysis indicated F2365 and EGD-e had an increased expression of proteins associated with cell envelope and membrane bioenergetics under anaerobic conditions, including thioredoxin-disulfide reductase and cell division proteins. Interestingly, HCC23 had an increase in several dehydrogenases following exposure to bile under aerobic conditions, suggesting that the NADH:NAD+ is altered and may impact bile resistance. Variations were observed in the expression of the cell shape proteins between strains, which corresponded to morphological differences observed by scanning electron microscopy. These data indicate that oxygen availability influences bile resistance. Further research is needed to decipher how these changes in metabolism impact pathogenicity in vivo and also the impact that this has on susceptibility of a host to listeriosis. PMID:27274623

  18. Prevalence of Listeria monocytogenes in poultry production in France.

    Science.gov (United States)

    Chemaly, Marianne; Toquin, Marie-Therese; Le Nôtre, Yolene; Fravalo, Philippe

    2008-10-01

    This study aimed to update and create a data set from laying hens and broilers regarding contamination by Listeria monocytogenes. Two hundred laying-hen flocks were sampled, with 88 flocks reared in cages and 112 reared on the floor. One hundred forty-five broiler flocks were sampled, with 85 conventional and 60 free-range flocks. A total of 774 and 725 samples were analyzed from laying hens and broilers, respectively. L. monocytogenes was detected in 31 of 200 flocks, yielding an estimated prevalence of 15.5% in laying-hen flocks. Among positive flocks, there appeared a significant (P = 0.004) difference between caged and floor-reared hens, with a higher detection in dust samples from floor-reared hens. In positive caged hen flocks, significant (P = 0.028) differences between dust and fecal samples appeared, with a higher detection in feces than in dust samples. In broiler flocks, L. monocytogenes was isolated in 46 of 145 flocks, yielding an estimated prevalence of 32% (28% in conventional flocks versus 37% in the free-range flocks). L. monocytogenes was isolated in samples taken from conventional flocks with a lower frequency than in free-range flocks (13 versus 18%, respectively). The serotyping of L. monocytogenes strains showed that the majority belonged to type 1/2a in laying-hen flocks (74.3%) and in broiler flocks (40.5%). A significant difference (P = 0.007) between laying hens and broilers was shown for serogroup 4 and for serovar 1/2b (P = 0.007); these serogroups were more prevalent in broilers (40%) than in laying hens (5.7%).

  19. Incorporation of Listeria monocytogenes strains in raw milk biofilms.

    Science.gov (United States)

    Weiler, Christiane; Ifland, Andrea; Naumann, Annette; Kleta, Sylvia; Noll, Matthias

    2013-02-01

    Biofilms develop successively on devices of milk production without sufficient cleaning and originate from the microbial community of raw milk. The established biofilm matrices enable incorporation of pathogens like Listeria monocytogenes, which can cause a continuous contamination of food processing plants. L. monocytogenes is frequently found in raw milk and non-pasteurized raw milk products and as part of a biofilm community in milk meters and bulk milk tanks. The aim of this study was to analyze whether different L. monocytogenes strains are interacting with the microbial community of raw milk in terms of biofilm formation in the same manner, and to identify at which stage of biofilm formation a selected L. monocytogenes strain settles best. Bacterial community structure and composition of biofilms were analyzed by a cloning and sequencing approach and terminal restriction fragment length polymorphism analysis (T-RFLP) based on the bacterial 16S rRNA gene. The chemical composition of biofilms was analyzed by Fourier transform infrared spectroscopy (FTIR), while settled L. monocytogenes cells were quantified by fluorescence in situ hybridization (FISH). Addition of individual L. monocytogenes strains to raw milk caused significant shifts in the biofilm biomass, in the chemical as well as in the bacterial community composition. Biofilm formation and attachment of L. monocytogenes cells were not serotype but strain specific. However, the added L. monocytogenes strains were not abundant since mainly members of the genera Citrobacter and Lactococcus dominated the bacterial biofilm community. Overall, added L. monocytogenes strains led to a highly competitive interaction with the raw milk community and triggered alterations in biofilm formation. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Mechanistic studies of the agmatine deiminase from Listeria monocytogenes.

    Science.gov (United States)

    Soares, Charles A; Knuckley, Bryan

    2016-06-01

    Listeria monocytogenes is a Gram-positive food-borne pathogen that is capable of living within extreme environments (i.e. low temperatures and pH). This ability to survive in such conditions may arise, at least in part, from agmatine catabolism via the agmatine deiminase system (AgDS). This catabolic pathway utilizes an agmatine deiminase (AgD) to hydrolyse agmatine into N-carbamoylputrescine (NCP), with concomitant release of ammonia, which increases the pH, thus mitigating the ill effects of the acidic environment. Given the potential significance of this pathway for cell survival, we set out to study the catalytic mechanism of the AgD encoded by L. monocytogenes In the present paper, we describe the catalytic mechanism employed by this enzyme based on pH profiles, pKa measurements of the active site cysteine and solvent isotope effects (SIE). In addition, we report inhibition of this enzyme by two novel AgD inhibitors, i.e. N-(4-aminobutyl)-2-fluoro-ethanimidamide (ABFA) and N-(4-aminobutyl)-2-chloro-ethanimidamide (ABCA). In contrast with other orthologues, L. monocytogenes AgD does not use the reverse protonation or substrate-assisted mechanism, which requires an active site cysteine with a high pKa and has been commonly seen in other members of the guanidinium-modifying enzyme (GME) superfamily. Instead, the L. monocytogenes AgD has a low pKa cysteine in the active site leading to an alternative mechanism of catalysis. This is the first time that this mechanism has been observed in the GME superfamily and is significant because it explains why previously developed mechanism-based inactivators of AgDs are ineffective against this orthologue. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

  1. Spontaneous Loss of Virulence in Natural Populations of Listeria monocytogenes.

    Science.gov (United States)

    Maury, Mylène M; Chenal-Francisque, Viviane; Bracq-Dieye, Hélène; Han, Lei; Leclercq, Alexandre; Vales, Guillaume; Moura, Alexandra; Gouin, Edith; Scortti, Mariela; Disson, Olivier; Vázquez-Boland, José A; Lecuit, Marc

    2017-11-01

    The pathogenesis of Listeria monocytogenes depends on the ability of this bacterium to escape from the phagosome of the host cells via the action of the pore-forming toxin listeriolysin O (LLO). Expression of the LLO-encoding gene ( hly ) requires the transcriptional activator PrfA, and both hly and prfA genes are essential for L. monocytogenes virulence. Here, we used the hemolytic activity of LLO as a phenotypic marker to screen for spontaneous virulence-attenuating mutations in L. monocytogenes Sixty nonhemolytic isolates were identified among a collection of 57,820 confirmed L. monocytogenes strains isolated from a variety of sources (0.1%). In most cases (56/60; 93.3%), the nonhemolytic phenotype resulted from nonsense, missense, or frameshift mutations in prfA Five strains carried hly mutations leading to a single amino acid substitution (G299V) or a premature stop codon causing strong virulence attenuation in mice. In one strain, both hly and gshF (encoding a glutathione synthase required for full PrfA activity) were missing due to genomic rearrangements likely caused by a transposable element. The PrfA/LLO loss-of-function (PrfA - /LLO - ) mutants belonged to phylogenetically diverse clades of L. monocytogenes , and most were identified among nonclinical strains (57/60). Consistent with the rare occurrence of loss-of-virulence mutations, we show that prfA and hly are under purifying selection. Although occurring at a low frequency, PrfA - /LLO - mutational events in L. monocytogenes lead to niche restriction and open an evolutionary path for obligate saprophytism in this facultative intracellular pathogen. Copyright © 2017 Maury et al.

  2. How Listeria monocytogenes organizes its surface for virulence

    Science.gov (United States)

    Carvalho, Filipe; Sousa, Sandra; Cabanes, Didier

    2014-01-01

    Listeria monocytogenes is a Gram-positive pathogen responsible for the manifestation of human listeriosis, an opportunistic foodborne disease with an associated high mortality rate. The key to the pathogenesis of listeriosis is the capacity of this bacterium to trigger its internalization by non-phagocytic cells and to survive and even replicate within phagocytes. The arsenal of virulence proteins deployed by L. monocytogenes to successfully promote the invasion and infection of host cells has been progressively unveiled over the past decades. A large majority of them is located at the cell envelope, which provides an interface for the establishment of close interactions between these bacterial factors and their host targets. Along the multistep pathways carrying these virulence proteins from the inner side of the cytoplasmic membrane to their cell envelope destination, a multiplicity of auxiliary proteins must act on the immature polypeptides to ensure that they not only maturate into fully functional effectors but also are placed or guided to their correct position in the bacterial surface. As the major scaffold for surface proteins, the cell wall and its metabolism are critical elements in listerial virulence. Conversely, the crucial physical support and protection provided by this structure make it an ideal target for the host immune system. Therefore, mechanisms involving fine modifications of cell envelope components are activated by L. monocytogenes to render it less recognizable by the innate immunity sensors or more resistant to the activity of antimicrobial effectors. This review provides a state-of-the-art compilation of the mechanisms used by L. monocytogenes to organize its surface for virulence, with special focus on those proteins that work “behind the frontline”, either supporting virulence effectors or ensuring the survival of the bacterium within its host. PMID:24809022

  3. Listeria monocytogenes as a vector for anti-cancer therapies.

    LENUS (Irish Health Repository)

    Tangney, Mark

    2012-01-31

    The intracellular pathogen Listeria monocytogenes represents a promising therapeutic vector for the delivery of DNA, RNA or protein to cancer cells or to prime immune responses against tumour-specific antigens. A number of biological properties make L. monocytogenes a promising platform for development as a vector for either gene therapy or as an anti-cancer vaccine vector. L. monocytogenes is particularly efficient in mediating internalization into host cells. Once inside cells, the bacterium produces specific virulence factors which lyse the vaculolar membrane and allow escape into the cytoplasm. Once in the cytosol, L. monocytogenes is capable of actin-based motility and cell-to-cell spread without an extracellular phase. The cytoplasmic location of L. monocytogenes is significant as this potentiates entry of antigens into the MHC Class I antigen processing pathway leading to priming of specific CD8(+) T cell responses. The cytoplasmic location is also beneficial for the delivery of DNA (bactofection) by L. monocytogenes whilst cell-to-cell spread may facilitate access of the vector to cells throughout the tumour. Several preclinical studies have demonstrated the ability of L. monocytogenes for intracellular gene or protein delivery in vitro and in vivo, and this vector has also displayed safety and efficacy in clinical trial. Here, we review the features of the L. monocytogenes host-pathogen interaction that make this bacterium such an attractive candidate with which to induce appropriate therapeutic responses. We focus primarily upon work that has led to attenuation of the pathogen, demonstrated DNA, RNA or protein delivery to tumour cells as well as research that shows the efficacy of L. monocytogenes as a vector for tumour-specific vaccine delivery.

  4. Prevalence and level of Listeria monocytogenes and other Listeria species in retail pre-packaged mixed vegetable salads in the UK.

    Science.gov (United States)

    Little, C L; Taylor, F C; Sagoo, S K; Gillespie, I A; Grant, K; McLauchlin, J

    2007-01-01

    As part of the European Commission (EC) co-ordinated programme for 2005, a study of pre-packaged ready-to-eat (RTE) mixed salads containing meat or seafood ingredients from retail premises was undertaken in the UK to determine the frequency and level of Listeria monocytogenes in these products. Almost all (99.8%; 2682/2686) samples were of satisfactory/acceptable microbiological quality. Two (0.1%) samples exceeded EC legal food safety criteria due to the presence of L. monocytogenes in excess of 100 cfu g(-1) (1.7 x 10(2), 9.9 x 10(2)cfu g(-1)) while another two (0.1%) were unsatisfactory due to L. welshimeri levels over 100 cfu g(-1) (1.2 x 10(3), 6.0 x 10(3) cfu g(-1)). Overall contamination of Listeria spp. and L. monocytogenes found in samples of mixed salads in the UK was 10.8% and 4.8%, respectively. Almost twice as many salad samples with meat ingredients were contaminated with Listeria spp. and L. monocytogenes (14.7% and 6.0%, respectively) compared to samples with seafood ingredients (7.4% and 3.8%, respectively). Pre-packaged mixed salads were contaminated with Listeria spp. and L. monocytogenes more frequently when: collected from sandwich shops; not packaged on the premises; stored or displayed above 8 degrees C. This study demonstrates that the control of L. monocytogenes in food manufacturing and at retail sale is essential in order to minimize the potential for this bacterium to be present in mixed salads at the point of consumption at levels hazardous to health.

  5. Portable exhausters POR-004 SKID B, POR-005 SKID C, POR-006 SKID D storage plan

    International Nuclear Information System (INIS)

    Nelson, O.D.; Keller, G.M.

    1997-01-01

    This document provides a storage plan for portable exhausters POR-004 SKID B, POR-005 SKID C, AND POR-006 SKID D. The exhausters will be stored until they are needed by the TWRS (Tank Waste Remediation Systems) Saltwell Pumping Program. The storage plan provides criteria for portable exhauster storage, periodic inspections during storage, and retrieval from storage

  6. Roka Listeria detection method using transcription mediated amplification to detect Listeria species in select foods and surfaces. Performance Tested Method(SM) 011201.

    Science.gov (United States)

    Hua, Yang; Kaplan, Shannon; Reshatoff, Michael; Hu, Ernie; Zukowski, Alexis; Schweis, Franz; Gin, Cristal; Maroni, Brett; Becker, Michael; Wisniewski, Michele

    2012-01-01

    The Roka Listeria Detection Assay was compared to the reference culture methods for nine select foods and three select surfaces. The Roka method used Half-Fraser Broth for enrichment at 35 +/- 2 degrees C for 24-28 h. Comparison of Roka's method to reference methods requires an unpaired approach. Each method had a total of 545 samples inoculated with a Listeria strain. Each food and surface was inoculated with a different strain of Listeria at two different levels per method. For the dairy products (Brie cheese, whole milk, and ice cream), our method was compared to AOAC Official Method(SM) 993.12. For the ready-to-eat meats (deli chicken, cured ham, chicken salad, and hot dogs) and environmental surfaces (sealed concrete, stainless steel, and plastic), these samples were compared to the U.S. Department of Agriculture/Food Safety and Inspection Service-Microbiology Laboratory Guidebook (USDA/FSIS-MLG) method MLG 8.07. Cold-smoked salmon and romaine lettuce were compared to the U.S. Food and Drug Administration/Bacteriological Analytical Manual, Chapter 10 (FDA/BAM) method. Roka's method had 358 positives out of 545 total inoculated samples compared to 332 positive for the reference methods. Overall the probability of detection analysis of the results showed better or equivalent performance compared to the reference methods.

  7. Enhanced biofilm formation in dual-species culture of Listeria monocytogenes and Ralstonia insidiosa

    Science.gov (United States)

    In the environment, many microorganisms coexist in communities as biofilms. The objective of this study was to investigate the interactions between Listeria monocytogenes and Ralstonia insidiosa in dual species biofilms. Biofilm development was measured using crystal violet in 96-well microtiter pla...

  8. Diversity assessment of Listeria monocytogenes biofilm formation: Impact of growth condition, serotype and strain origin

    NARCIS (Netherlands)

    Kadam, S.R.; Besten, den H.M.W.; Veen, van der S.; Zwietering, M.H.; Moezelaar, R.; Abee, T.

    2013-01-01

    The foodborne pathogen Listeria monocytogenes has the ability to produce biofilms in food-processing environments and then contaminate food products, which is a major concern for food safety. The biofilm forming behavior of 143 L. monocytogenes strains was determined in four different media that

  9. IDENTIFIKASI Listeria spp. PADA PANGAN JAJANAN BERBASIS IKAN DI KOTA BOGOR

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    Elia Yuswita

    2016-06-01

    Full Text Available L. monocytogenes contamination in processed food, especially fish-based snack, may results from contaminated raw materials, underprocessed or recontamination. The aims of this study were to identify the presence of Listeria spp. especially L. monocytogenes by PCR method and biochemical methods, as well as calculate the prevalence of Listeria spp. in fish-based snack food in Bogor. This study was conducted of 4 steps: (1 determination of L. monocytogenes’s DNA limit detection, (2 sample preparation, (3 identification of L. monocytogenes with real-time PCR, and (4 identification of Listeria spp. with biochemical methods. The results showed that DNA detection limits of L. monocytogenes in fish meatball and otak-otak were at 8.3x102 and 2.9x102 CFU/g, respectively. The study on 65 samples indicated that contamination of L. monocytogenes was not observed, but other species of Listeria spp., namely L. grayi and L. innocua, were found. The prevalence of L. grayi and L. innocua in siomay was at 5.9%, while the prevalence of L. grayi in shrimp meatballs, fish meat balls, fried meatballs was at 8.3, 9.1, and 50%, respectively. Furthermore, L. innocua from takoyaki samples with a prevalence of 20% was observed.

  10. REAL-TIME PCR DETECTION OF LISTERIA MONOCYTOGENES IN FOOD SAMPLES OF ANIMAL ORIGIN

    Directory of Open Access Journals (Sweden)

    Jaroslav Pochop

    2013-02-01

    Full Text Available The aim of this study was to follow the contamination of food with Listeria monocytogenes by using Step One real time polymerase chain reaction (PCR. We used the PrepSEQ Rapid Spin Sample Preparation Kit for isolation of DNA and SensiFAST SYBR Hi-ROX Kit for the real-time PCR performance. In 24 samples of food of animal origin without incubation were detected strains of Listeria monocytogenes in 15 samples (swabs. Nine samples were negative. Our results indicated that the real-time PCR assay developed in this study could sensitively detect Listeria monocytogenes in food of animal origin without incubation. This could prevent infection caused by Listeria monocytogenes, and also could benefit food manufacturing companies by extending their product’s shelf-life as well as saving the cost of warehousing their food products while awaiting pathogen testing results. The rapid real-time PCR-based method performed very well compared to the conventional method. It is a fast, simple, specific and sensitive way to detect nucleic acids, which could be used in clinical diagnostic tests in the future.

  11. Listeria monocytogenes Identification in Food of Animal Origin Used with Real Time PCR

    Directory of Open Access Journals (Sweden)

    Jaroslav Pochop

    2013-10-01

    Full Text Available The aim of this study was to follow the contamination of food with Listeria monocytogenes by using Step One real time polymerase chain reaction (RT PCR. We used the PrepSEQ Rapid Spin Sample Preparation Kit for isolation of DNA and SensiFAST SYBR Hi-ROX Kit for the real-time PCR performance. In 20 samples of food of animal origin with incubation were detected strains of Listeria monocytogenes in 9 samples (swabs. Eleven samples were negative. Our results indicated that the real-time PCR assay developed in this study could sensitively detect Listeria monocytogenes in food of animal origin without incubation. This could prevent infection caused by Listeria monocytogenes, and also could benefit food manufacturing companies by extending their product’s shelf-life as well as saving the cost of warehousing their food products while awaiting pathogen testing results. The rapid real-time PCR-based method performed very well compared to the conventional method. It is a fast, simple, specific and sensitive way to detect nucleic acids, which could be used in clinical diagnostic tests in the future.

  12. An outbreak of an unusual strain of Listeria monocytogenes infection in North-East Scotland

    Directory of Open Access Journals (Sweden)

    Emmanuel Okpo

    2015-11-01

    Full Text Available Summary: Listeria monocytogenes infection is an important cause of illness and hospitalization in vulnerable individuals. In the present study, we describe a community outbreak of Listeria monocytogenes in the North-East region of Scotland, which was epidemiologically, environmentally and microbiologically linked to a local meat product and ready-to-eat product manufacturer. Infected individuals were interviewed, and an environmental investigation was conducted. Clinical and environmental samples were tested by culture, and isolates were typed by fluorescent amplified fragment length polymorphism (fAFLP. Three cases of Listeria monocytogenes were linked geographically, had the same serotype (1/2a and were indistinguishable by fAFLP type XII.6. The human, food and environmental isolates were of the same serotype and were indistinguishable by molecular typing.This is the first community outbreak of L. monocytogenes reported in Scotland since the current outbreak surveillance was established in 1996. Epidemiological and laboratory evidence indicated poor hand hygiene, unhygienic practices and cross-contamination throughout the manufacturing process of ready-to-eat foods as a possible cause of the outbreak. More stringent control of commercial food establishments that provide ready-to-eat food and the need to advise specifically vulnerable groups, e.g., pregnant women, of the risk of L. monocytogenes in ready-to-eat food is urgently needed. Keywords: Listeria monocytogenes, Outbreak, Foodborne, Community acquired infection, Listeriosis

  13. Visualization of gold and platinum nanoparticles interacting with Salmonella enteritidis and Listeria monocytogenes

    DEFF Research Database (Denmark)

    Sawosz, Ewa; Chwalibog, André; Szeliga, Jacek

    2010-01-01

    -Au and nano-Pt respectively), with Salmonella Enteritidis (Gram-negative) and Listeria monocytogenes (Gram-positive), to reveal possibilities of constructing bacteria-nanoparticle vehicles. Methods: Hydrocolloids of nano-Au or nano-Pt were added to two bacteria suspensions in the following order: nano...... as a vehicle to deliver nano-Pt to specific points in the body....

  14. Inactivation of Listeria monocytogenes by disinfectants and bacteriophages in suspension and stainless steel carrier tests

    NARCIS (Netherlands)

    Chaitiemwong, N.; Hazeleger, W.C.; Beumer, R.R.

    2014-01-01

    To simulate food contact surfaces with pits or cracks, stainless steel plates with grooves (depths between 0.2 and 5 mm) were constructed. These plates were artificially contaminated with Listeria monocytogenes in clean conditions, with organic soiling, or after 14 days of biofilm formation after

  15. Prevalence and antimicrobial resistance of Listeria monocytogenes isolated in chicken slaughterhouses in Northern Greece.

    Science.gov (United States)

    Sakaridis, I; Soultos, N; Iossifidou, E; Papa, A; Ambrosiadis, I; Koidis, P

    2011-06-01

    This study was conducted to determine the prevalence and antimicrobial resistance of Listeria monocytogenes recovered from chicken carcasses in slaughterhouses in Northern Greece. A total of 100 poultry samples (300 carcasses) were examined for Listeria spp. The samples were neck skin taken from four different slaughterhouses in Northern Greece. Forty samples were also taken from the environment of the slaughterhouses. Identification of L. monocytogenes was carried out by PCR and fingerprinting of the isolates by random amplified polymorphic DNA. L. monocytogenes strains isolated from chicken carcasses and from the environment of the slaughterhouses were also examined for antibiotic resistance. Fifty-five isolates of L. monocytogenes were tested for susceptibility to 20 antibiotics using the disk diffusion method. Listeria spp. were present in 99 of the poultry samples tested (99%), and 38 yielded L monocytogenes (38%). L. monocytogenes was also isolated in 80% of samples from the environment of a certain slaughterhouse, while the other slaughterhouses were found to be contaminated only with Listeria spp. All isolates were resistant to nalidixic acid and oxolinic acid, the majority of them to clindamycin, and only a few to tetracycline and oxytetracycline, whereas they were found to be susceptible to all other antimicrobials. The results of this study demonstrate a high prevalence of L. monocytogenes contamination in chicken carcasses, and all isolates were found to be sensitive to the antimicrobials most commonly used to treat human listeriosis.

  16. A novel suicide plasmid for efficient gene mutation in Listeria monocytogenes

    Science.gov (United States)

    Although several plasmids have been used in Listeria monocytogenes for generating mutants by allelic exchange, construction of L. monocytogenes mutants has been inefficient due to lack of effective selection markers for first and second recombination events. To address this problem, we have develope...

  17. Extracting additional risk managers information from a risk assessment of Listeria monocytogenes in deli meats

    NARCIS (Netherlands)

    Pérez-Rodríguez, F.; Asselt, van E.D.; García-Gimeno, R.M.; Zurera, G.; Zwietering, M.H.

    2007-01-01

    The risk assessment study of Listeria monocytogenes in ready-to-eat foods conducted by the U.S. Food and Drug Administration is an example of an extensive quantitative microbiological risk assessment that could be used by risk analysts and other scientists to obtain information and by managers and

  18. Efficacy of antimicrobials extracted from organic pecan shell for inhibiting the growth of Listeria spp.

    Science.gov (United States)

    Babu, Dinesh; Crandall, Philip G; Johnson, Casey L; O'Bryan, Corliss A; Ricke, Steven C

    2013-12-01

    Growers and processors of USDA certified organic foods are in need of suitable organic antimicrobials. The purpose of the research reported here was to develop and test natural antimicrobials derived from an all-natural by-product, organic pecan shells. Unroasted and roasted organic pecan shells were subjected to solvent free extraction to produce antimicrobials that were tested against Listeria spp. and L. monocytogenes serotypes to determine the minimum inhibitory concentrations (MIC) of antimicrobials. The effectiveness of pecan shell extracts were further tested using a poultry skin model system and the growth inhibition of the Listeria cells adhered onto the skin model were quantified. The solvent free extracts of pecan shells inhibited Listeria strains at MICs as low as 0.38%. The antimicrobial effectiveness tests on a poultry skin model exhibited nearly a 2 log reduction of the inoculated cocktail mix of Listeria strains when extracts of pecan shell powder were used. The extracts also produced greater than a 4 log reduction of the indigenous spoilage bacteria on the chicken skin. Thus, the pecan shell extracts may prove to be very effective alternative antimicrobials against food pathogens and supplement the demand for effective natural antimicrobials for use in organic meat processing. © 2013 Institute of Food Technologists®

  19. A role for host cell exocytosis in InlB-mediated internalisation of Listeria monocytogenes.

    Science.gov (United States)

    Van Ngo, Hoan; Bhalla, Manmeet; Chen, Da-Yuan; Ireton, Keith

    2017-11-01

    The bacterial surface protein InlB mediates internalisation of Listeria monocytogenes into human cells through interaction with the host receptor tyrosine kinase, Met. InlB-mediated entry requires localised polymerisation of the host actin cytoskeleton. Apart from actin polymerisation, roles for other host processes in Listeria entry are unknown. Here, we demonstrate that exocytosis in the human cell promotes InlB-dependent internalisation. Using a probe consisting of VAMP3 with an exofacial green fluorescent protein tag, focal exocytosis was detected during InlB-mediated entry. Exocytosis was dependent on Met tyrosine kinase activity and the GTPase RalA. Depletion of SNARE proteins by small interfering RNA demonstrated an important role for exocytosis in Listeria internalisation. Depletion of SNARE proteins failed to affect actin filaments during internalisation, suggesting that actin polymerisation and exocytosis are separable host responses. SNARE proteins were required for delivery of the human GTPase Dynamin 2, which promotes InlB-mediated entry. Our results identify exocytosis as a novel host process exploited by Listeria for infection. © 2017 John Wiley & Sons Ltd.

  20. Survival of Listeria monocytogenes on a conveyor belt material with or without antimicrobial additives

    NARCIS (Netherlands)

    Chaitiemwong, N.; Hazeleger, W.C.; Beumer, R.R.

    2010-01-01

    Survival of Listeria monocytogenes on a conveyor belt material with or without antimicrobial additives, in the absence or presence of food debris from meat, fish and vegetables and at temperatures of 10, 25 and 37 °C was investigated. The pathogen survived best at 10 °C, and better at 25 °C than at

  1. Occurrence of Listeria species in different captive wild animals of Nandankanan Zoo, Baranga, Odisha, India

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    L.N. Sarangi

    2013-01-01

    Full Text Available Listeria species were isolated from faecal samples collected from different captive wild animals of Nandankanan Zoo, Baranga, Odisha, using selective enrichment medium. The isolates were characterized based on their cell morphology, biochemical and sugar fermentation characteristics as well as culture morphology. Further, in vitro and in vivo pathogenicity tests were carried out to assess the pathogenic potential of the isolates. Listeria were found in 24 (23.07% of the total 104 faecal samples. Listeria were isolated from the samples of tiger, bear, hyena, leopard, zebra, elephant, jackal, lion, barking deer, porcupine, chital, monkey and wild boar. Out of the 24 Listeria isolates 11 were confirmed as L. monocytogenes. The other 13 isolates included L. innocua, L. seeligeri, L. welshimeri and L. ivanovii. The pathogenicity study revealed that only four isolates were pathogenic. Three of these were L. monocytogenes isolated from tiger, hyena and elephant and one was L. ivanovii isolated from leopard. Antibiotic sensitivity of the 24 isolates was high towards ciprofloxacin, levofloxacin, amoxicillin, azithromycin and enrofloxacin. The isolates showed resistance towards oxytetracyclin, gentamicin, cephadroxil, penicillin- G and nalidixic acid.

  2. Combined action of S-carvone and mild heat treatment on Listeria monocytogenes Scott A

    NARCIS (Netherlands)

    Karatzas, A.K.; Bennik, M.H.J.; Smid, E.J.; Kets, E.P.W.

    2000-01-01

    The combined action of the plant-derived volatile, S-carvone, and mild heat treatment on the food-borne pathogen, Listeria monocytogenes, was evaluated. The viability of exponential phase cultures grown at 8 °C could be reduced by 1.3 log units after exposure to S-carvone (5 mmol 1-1) for 30 min at

  3. [Risk assessment of Listeria monocytogenes in deli meats and vegetable salads].

    Science.gov (United States)

    Tian, Jing; Liu, Xiu-mei

    2009-09-01

    To analysis risk from Listeria monocytogenes in deli meats and vegetable salads. Use Risk Ranger which is a software programme developed by the University of Hobart, Australia and answer 11 questions on affecting the risk from hazards in the specific foods by combining data from national foodborne diseases surveillance network and some references to make semi-quantitative risk assessment for the specific food. Relative risk from Listeria monocytogenes in deli meats and vegetable salads is 61 and 52, respectively. Incidence of listeriosis caused by deli meats-Listeria monocytogenes pairs and vegetable salads-Listeria monocytogenes pairs is 5.4 and 0.2 cases per million people, respectively. Risk from the former is 32 times than that from the latter. By changing the selection for some risk factors in the model, it was known that the risks from two food-hazard combinations could decrease 10 times, if taking necessary actions after processing. Deli meats is a kind of high risk food for listeriosis.

  4. A dynamical systems approach to actin-based motility in Listeria monocytogenes

    Science.gov (United States)

    Hotton, S.

    2010-11-01

    A simple kinematic model for the trajectories of Listeria monocytogenes is generalized to a dynamical system rich enough to exhibit the resonant Hopf bifurcation structure of excitable media and simple enough to be studied geometrically. It is shown how L. monocytogenes trajectories and meandering spiral waves are organized by the same type of attracting set.

  5. Evaluation of Listeria monocytogenes survival and infectivity in non-traditional agricultural waters

    Science.gov (United States)

    Introduction: Listeria monocytogenes (Lm) is an enteric bacterium that can be found in environmental reservoirs. Restricted water availability for agriculture has increased interest in surface and reuse water sources which could potentially transmit Lm. Purpose: Persistence and infectivity of Lm re...

  6. Listeria monocytogenes infection of HD11, chicken macrophage-like cells.

    Science.gov (United States)

    Jarvis, N A; Donaldson, J R; O'Bryan, C A; Ricke, S C; Crandall, P G

    2017-04-01

    Listeria monocytogenes can be carried by and infect poultry, although the clinical disease in birds is rare. Escape from macrophage phagocytosis is a key step in pathogenesis for L. monocytogenes. Therefore, we investigated the infection of the chicken macrophage-like cell line HD11 with 2 strains of L. monocytogenes EGD-e and Scott A. After infection, L. monocytogenes was quantified by spread plating and HD11 was quantified with trypan blue exclusion stain before enumeration. The standard macrophage killing protocols require washing the cell monolayers 3 times with PBS, which was found to negatively influence HD11 monolayers. Maximum bacterial densities within macrophages were not different between the 2 Listeria strains. HD11 required more than 11 h to effectively reduce intracellular L. monocytogenes Scott A, and Scott A was more susceptible to HD11 killing than EGD-e. It appears that Listeria infection initially causes attenuation of HD11 growth, and infected HD11 cells do not begin to lyse until at least 11 h post infection. These results suggest that there are subtle strain to strain differences in response to HD11 macrophage phagocytosis. The long lead-time required for HD11 to kill L. monocytogenes cells means that there is sufficient time available for chicken macrophages to circulate in the blood and transfer the intracellular Listeria to multiple tissues. © 2016 Poultry Science Association Inc.

  7. Listeria monocytogenes and Shigella flexneri Activate the NLRP1B Inflammasome.

    Science.gov (United States)

    Neiman-Zenevich, Jana; Stuart, Sarah; Abdel-Nour, Mena; Girardin, Stephen E; Mogridge, Jeremy

    2017-11-01

    Activation of the innate immune receptor NLRP1B leads to the formation of an inflammasome, which induces autoproteolytic processing of pro-caspase-1, and ultimately to the release of inflammatory cytokines and to the execution of pyroptosis. One of the signals to which NLRP1B responds is metabolic stress that occurs in cells deprived of glucose or treated with metabolic inhibitors. NLRP1B might therefore sense microbial infection, as intracellular pathogens such as Listeria monocytogenes and Shigella flexneri cause metabolic stress as a result of nutrient scavenging and host cell damage. Here we addressed whether these pathogens activate the NLRP1B inflammasome. We found that Listeria infection activated the NLRP1B inflammasome in a reconstituted fibroblast model. Activation of NLRP1B by Listeria was diminished in an NLRP1B mutant shown previously to be defective at detecting energy stress and was dependent on the expression of listeriolysin O (LLO), a protein required for vacuolar escape. Infections of either Listeria or Shigella activated NLRP1B in the RAW264.7 murine macrophage line, which expresses endogenous NLRP1B. We conclude that NLRP1B senses cellular infection by distinct invasive pathogens. Copyright © 2017 American Society for Microbiology.

  8. Morphological change and decreasing transfer rate of biofilm-featured Listeria monocytogenes EGDe

    Science.gov (United States)

    Listeria monocytogenes, a lethal foodborne pathogen, has the ability to resist the hostile food-processing environment and, thus, frequently contaminates ready-to-eat foods during processing. It is commonly accepted that L. monocytogenes’ tendency to generate biofilms on various surfaces enhances it...

  9. Draft Genome Sequences of Historical Listeria monocytogenes from Human Listeriosis, 1933

    Science.gov (United States)

    We report here the draft genome sequences of two Listeria monocytogenes strains from some of the earliest reported cases of human listeriosis in North America. The strains were isolated in 1933 from patients in Massachusetts and Connecticut, USA, and belong to the widely disseminated hypervirulent c...

  10. Isolation and characterization of an atypical Listeria monocytogenes associated with a canine urinary tract infection

    Science.gov (United States)

    Listeria monocytogenes, a well-described cause of encephalitis and abortion in ruminants and of food-borne illness in humans, is rarely associated with disease in companion animals. A case of urinary tract infection associated with an atypical, weakly hemolytic L. monocytogenes strain is described i...

  11. Outbreak of Listeria monocytogenes infections linked to a pasteurized ice cream product served to hospitalized patients.

    Science.gov (United States)

    Rietberg, K; Lloyd, J; Melius, B; Wyman, P; Treadwell, R; Olson, G; Kang, M-G; Duchin, J S

    2016-10-01

    Two cases of hospital-acquired listeriosis were linked to a commercially produced, pasteurized ice cream mix. Manufacturers should implement safety measures from the Food Safety Modernization Act to minimize the risk of Listeria contamination. Dietary guidelines for persons at high risk of listeriosis may need revision to recognize the potential risk from pasteurized products.

  12. Rapid detection of Listeria monocytogenes in milk using confocal micro-Raman spectroscopy and chemometric analysis.

    Science.gov (United States)

    Wang, Junping; Xie, Xinfang; Feng, Jinsong; Chen, Jessica C; Du, Xin-jun; Luo, Jiangzhao; Lu, Xiaonan; Wang, Shuo

    2015-07-02

    Listeria monocytogenes is a facultatively anaerobic, Gram-positive, rod-shape foodborne bacterium causing invasive infection, listeriosis, in susceptible populations. Rapid and high-throughput detection of this pathogen in dairy products is critical as milk and other dairy products have been implicated as food vehicles in several outbreaks. Here we evaluated confocal micro-Raman spectroscopy (785 nm laser) coupled with chemometric analysis to distinguish six closely related Listeria species, including L. monocytogenes, in both liquid media and milk. Raman spectra of different Listeria species and other bacteria (i.e., Staphylococcus aureus, Salmonella enterica and Escherichia coli) were collected to create two independent databases for detection in media and milk, respectively. Unsupervised chemometric models including principal component analysis and hierarchical cluster analysis were applied to differentiate L. monocytogenes from Listeria and other bacteria. To further evaluate the performance and reliability of unsupervised chemometric analyses, supervised chemometrics were performed, including two discriminant analyses (DA) and soft independent modeling of class analogies (SIMCA). By analyzing Raman spectra via two DA-based chemometric models, average identification accuracies of 97.78% and 98.33% for L. monocytogenes in media, and 95.28% and 96.11% in milk were obtained, respectively. SIMCA analysis also resulted in satisfied average classification accuracies (over 93% in both media and milk). This Raman spectroscopic-based detection of L. monocytogenes in media and milk can be finished within a few hours and requires no extensive sample preparation. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Certain dietary carbohydrates promote Listeria infection in a guinea pig model, while others prevent it

    DEFF Research Database (Denmark)

    Ebersbach, Tine; Jørgensen, Julie Boeck; Heegaard, Peter M. H.

    2010-01-01

    of five non-digestible carbohydrates on the resistance of guinea pigs to Listeria monocytogenes infections. Animals were fed a diet supplemented with 10% xylooligosaccharides (XOS), galactooligosaccharides (GOS), inulin, apple pectin or polydextrose for three weeks before oral infection with a mixture...

  14. Effect of high pressure processing on reduction of Listeria monocytogenes in packaged Queso Fresco

    Science.gov (United States)

    The effect of high hydrostatic pressure processing (HPP) on the survival of a five-strain rifampicin-resistant cocktail of Listeria monocytogenes in Queso Fresco (QF) was evaluated as a post-packaging intervention. QF was made using pasteurized, homogenized milk, was starter-free and was not pressed...

  15. Modeling the effect of temperature on survival rate of Listeria monocytogenes in yogurt.

    Science.gov (United States)

    Szczawiński, J; Szczawińska, M E; Łobacz, A; Jackowska-Tracz, A

    2016-01-01

    The aim of the study was to (i) evaluate the behavior of Listeria monocytogenes in a commercially produced yogurt, (ii) determine the survival/inactivation rates of L. monocytogenes during cold storage of yogurt and (iii) to generate primary and secondary mathematical models to predict the behavior of these bacteria during storage at different temperatures. The samples of yogurt were inoculated with the mixture of three L. monocytogenes strains and stored at 3, 6, 9, 12 and 15°C for 16 days. The number of listeriae was determined after 0, 1, 2, 3, 5, 7, 9, 12, 14 and 16 days of storage. From each sample a series of decimal dilutions were prepared and plated onto ALOA agar (agar for Listeria according to Ottaviani and Agosti). It was found that applied temperature and storage time significantly influenced the survival rate of listeriae (pbacteria was found in the samples stored at 6°C (D-10 value = 243.9 h), whereas the highest reduction in the number of the bacteria was observed in the samples stored at 15°C (D-10 value = 87.0 h). The number of L. monocytogenes was correlated with the pH value of the samples (pyogurt stored under temperature range from 3 to 15°C, however, the polynomial model gave a better fit to the experimental data.

  16. A novel Listeria monocytogenes-based DNA delivery system for cancer gene therapy.

    LENUS (Irish Health Repository)

    van Pijkeren, Jan Peter

    2012-01-31

    Bacteria-mediated transfer of plasmid DNA to mammalian cells (bactofection) has been shown to have significant potential as an approach to express heterologous proteins in various cell types. This is achieved through entry of the entire bacterium into cells, followed by release of plasmid DNA. In a murine model, we show that Listeria monocytogenes can invade and spread in tumors, and establish the use of Listeria to deliver genes to tumors in vivo. A novel approach to vector lysis and release of plasmid DNA through antibiotic administration was developed. Ampicillin administration facilitated both plasmid transfer and safety control of vector. To further improve on the gene delivery system, we selected a Listeria monocytogenes derivative that is more sensitive to ampicillin, and less pathogenic than the wild-type strain. Incorporation of a eukaryotic-transcribed lysin cassette in the plasmid further increased bacterial lysis. Successful gene delivery of firefly luciferase to growing tumors in murine models and to patient breast tumor samples ex vivo was achieved. The model described encompasses a three-phase treatment regimen, involving (1) intratumoral administration of vector followed by a period of vector spread, (2) systemic ampicillin administration to induce vector lysis and plasmid transfer, and (3) systemic administration of combined moxifloxacin and ampicillin to eliminate systemic vector. For the first time, our results reveal the potential of Listeria monocytogenes for in vivo gene delivery.

  17. Isolation, identification, and characterization of Listeria spp. from various animal origin foods

    Science.gov (United States)

    Nayak, Deepti N.; Savalia, C. V.; Kalyani, I. H.; Kumar, Rajeev; Kshirsagar, D. P.

    2015-01-01

    Aim: The present study was undertaken with the prime objective of isolating and identifying Listeria spp. from various foods of animal origin sold at retail market outlets in the city of Navsari, Gujarat. Materials and Methods: Total 200 samples comprising of milk, milk products, meat, and fish (50 each) collected aseptically from local market which were subjected first to pre-enrichment in half strength Fraser broth followed by enrichment in full strength Fraser broth and subsequent plating on PALCAM agar. The growth with the typical colony characteristics were further identified up to species level on the basis of their morphological and biochemical characteristics. Cultures identified as Listeria monocytogenes were further subjected to in vitro pathogenicity tests and detection of different virulence-associated genes viz. actA, hlyA, and iap using polymerase chain reaction. Results: Of the total 200 food samples of animal origin; 18 (9%) were found positive for Listeria spp. which were identified as Listeria seeligeri (6, 33.3%), Listeria innocua (5, 27.7%), Listeria welshimeri (4, 22.2%), and L. monocytogenes (3, 16.6%). The highest prevalence was observed in milk samples (8). Species wise, 6 isolates of L. seeligeri which included two each from cow milk, buffalo milk, and meat samples; 5 L. innocua isolates included four recovered from fish and one from meat sample; 4 L. welshimeri comprised of two isolates from ice cream and one each from buffalo milk and meat sample; and 3 isolates of L. monocytogenes recovered from milk (1 cow and 2 buffalo milk). All 3 L. monocytogenes isolates screened for the presence of virulence genes viz. actA, hlyA, and iap using the specific primers revealed the presence of all the genes suggesting the possibility of danger of foodborne listeriosis among raw milk consumers. Conclusion: Listeria spp. was isolated from 9% (18/200) of the animal origin food samples viz.; milk, milk products, meat, and fish with the highest prevalence

  18. Isolation, identification, and characterization of Listeria spp. from various animal origin foods

    Directory of Open Access Journals (Sweden)

    Deepti N. Nayak

    2015-06-01

    Full Text Available Aim: The present study was undertaken with the prime objective of isolating and identifying Listeria spp. from various foods of animal origin sold at retail market outlets in the city of Navsari, Gujarat. Materials and Methods: Total 200 samples comprising of milk, milk products, meat, and fish (50 each collected aseptically from local market which were subjected first to pre-enrichment in half strength Fraser broth followed by enrichment in full strength Fraser broth and subsequent plating on PALCAM agar. The growth with the typical colony characteristics were further identified up to species level on the basis of their morphological and biochemical characteristics. Cultures identified as Listeria monocytogenes were further subjected to in vitro pathogenicity tests and detection of different virulence associated genes viz. actA, hlyA, and iap using polymerase chain reaction. Results: Of the total 200 food samples of animal origin; 18 (9% were found positive for Listeria spp. which were identified as Listeria seeligeri (6, 33.3%, Listeria innocua (5, 27.7%, Listeria welshimeri (4, 22.2%, and L. monocytogenes (3, 16.6%. The highest prevalence was observed in milk samples (8. Species wise, 6 isolates of L. seeligeri which included two each from cow milk, buffalo milk, and meat samples; 5 L. innocua isolates included four recovered from fish and one from meat sample; 4 L. welshimeri comprised of two isolates from ice cream and one each from buffalo milk and meat sample; and 3 isolates of L. monocytogenes recovered from milk (1 cow and 2 buffalo milk. All 3 L. monocytogenes isolates screened for the presence of virulence genes viz. actA, hlyA, and iap using the specific primers revealed the presence of all the genes suggesting the possibility of danger of foodborne listeriosis among raw milk consumers. Conclusion: Listeria spp. was isolated from 9% (18/200 of the animal origin food samples viz.; milk, milk products, meat, and fish with the highest

  19. Control Multivariable por Desacoplo

    Directory of Open Access Journals (Sweden)

    Fernando Morilla

    2013-01-01

    Full Text Available Resumen: La interacción entre variables es una característica inherente de los procesos multivariables, que dificulta su operación y el diseño de sus sistemas de control. Bajo el paradigma de Control por desacoplo se agrupan un conjunto de metodologías, que tradicionalmente han estado orientadas a eliminar o reducir la interacción, y que recientemente algunos investigadores han reorientado con objetivos de solucionar un problema tan complejo como es el control multivariable. Parte del material descrito en este artículo es bien conocido en el campo del control de procesos, pero la mayor parte de él son resultados de varios años de investigación de los autores en los que han primado la generalización del problema, la búsqueda de soluciones de fácil implementación y la combinación de bloques elementales de control PID. Esta conjunción de intereses provoca que no siempre se pueda conseguir un desacoplo perfecto, pero que sí se pueda conseguir una considerable reducción de la interacción en el nivel básico de la pirámide de control, en beneficio de otros sistemas de control que ocupan niveles jerárquicos superiores. El artículo resume todos los aspectos básicos del Control por desacoplo y su aplicación a dos procesos representativos: una planta experimental de cuatro tanques acoplados y un modelo 4×4 de un sistema experimental de calefacción, ventilación y aire acondicionado. Abstract: The interaction between variables is inherent in multivariable processes and this fact may complicate their operation and control system design. Under the paradigm of decoupling control, several methodologies that traditionally have been addressed to cancel or reduce the interactions are gathered. Recently, this approach has been reoriented by several researchers with the aim to solve such a complex problem as the multivariable control. Parts of the material in this work are well known in the process control field; however, most of them are

  20. Visualization of gold and platinum nanoparticles interacting with Salmonella Enteritidis and Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    Ewa Sawosz

    2010-08-01

    Full Text Available Ewa Sawosz1, André Chwalibog2, Jacek Szeliga3, Filip Sawosz2, Marta Grodzik1, Marlena Rupiewicz1, Tomasz Niemiec1, Katarzyna Kacprzyk11Division of Biotechnology and Biochemistry of Nutrition, Warsaw University of Life Sciences, Warsaw, Poland; 2Department of Basic Animal and Veterinary Sciences, University of Copenhagen, Copenhagen, Denmark; 3Division of Microbiology of Analytical Centre, Warsaw University of Life Sciences, Warsaw, PolandPurpose: Rapid development of nanotechnology has recently brought significant attention to the extraordinary biological features of nanomaterials. The objective of the present ­investigation was to evaluate morphological characteristics of the assembles of gold and platinum nanoparticles (nano-Au and nano-Pt respectively, with Salmonella Enteritidis (Gram-negative and Listeria monocytogenes (Gram-positive, to reveal possibilities of constructing bacteria-nanoparticle vehicles.Methods: Hydrocolloids of nano-Au or nano-Pt were added to two bacteria suspensions in the following order: nano-Au + Salmonella Enteritidis; nano-Au + Listeria monocytogenes; nano-Pt + Salmonella Enteritidis; nano-Pt + Listeria monocytogenes. Samples were inspected by transmission electron microscope.Results: Visualization of morphological interaction between nano-Au and Salmonella Enteritidis and Listeria monocytogenes, showed that nano-Au were aggregated within flagella or biofilm network and did not penetrate the bacterial cell. The analysis of morphological effects of interaction of nano-Pt with bacteria revealed that nano-Pt entered cells of Listeria monocytogenes and were removed from the cells. In the case of Salmonella Enteritidis, nano-Pt were seen inside bacteria cells, probably bound to DNA and partly left bacterial cells. After washing and centrifugation, some of the nano-Pt-DNA complexes were observed within Salmonella Enteritidis.Conclusion: The results indicate that the bacteria could be used as a vehicle to deliver nano

  1. Sakacin-A antimicrobial packaging for decreasing Listeria contamination in thin-cut meat: preliminary assessment.

    Science.gov (United States)

    Barbiroli, Alberto; Musatti, Alida; Capretti, Giorgio; Iametti, Stefania; Rollini, Manuela

    2017-02-01

    Minimally processed ready-to-eat products are considered a high-risk food because of the possibility of contamination with pathogenic bacteria, including Listeria monocytogenes from the animal reservoir, and the minimal processing they undergo. In this study, a sakacin-A anti-Listeria active package was developed and tested on thin-cut veal meat slices (carpaccio). Enriched food-grade sakacin-A was obtained from a cell-free supernatant of a Lactobacillus sakei culture and applied (0.63 mg cm -2 ) onto the surface of polyethylene-coated paper sheets to obtain an active antimicrobial package. The coating retained antimicrobial features, indicating that the process did not affect sakacin-A functionality, as evidenced in tests carried out in vitro. Thin-cut veal meat slices inoculated with Listeria innocua (a surrogate of pathogenic L. monocytogenes) were laid on active paper sheets. After 48 h incubation at 4 °C, the Listeria population was found to be 1.5 log units lower with respect to controls (3.05 vs 4.46 log colony-forming units (CFU) g -1 ). This study demonstrates the possibility of using an antimicrobial coating containing sakacin-A to inhibit or decrease the Listeria population in ready-to-eat products, thus lowering the risk of food-related diseases. © 2016 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2016 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  2. Investigation of Listeria, Salmonella, and toxigenic Escherichia coli in various pet foods.

    Science.gov (United States)

    Nemser, Sarah M; Doran, Tara; Grabenstein, Michael; McConnell, Terri; McGrath, Timothy; Pamboukian, Ruiqing; Smith, Angele C; Achen, Maya; Danzeisen, Gregory; Kim, Sun; Liu, Yong; Robeson, Sharon; Rosario, Grisel; McWilliams Wilson, Karen; Reimschuessel, Renate

    2014-09-01

    The Veterinary Laboratory Investigation and Response Network (Vet-LIRN), in collaboration with the Food Emergency Response Network (FERN) and its Microbiology Cooperative Agreement Program (MCAP) laboratories, conducted a study to evaluate the prevalence of selected microbial organisms in various types of pet foods. The goal of this blinded study was to help the Center for Veterinary Medicine prioritize potential future pet food-testing efforts. The study also increased the FERN laboratories' screening capabilities for foodborne pathogens in animal feed matrices, since such pathogens may also be a significant health risk to consumers who come into contact with pet foods. Six U.S. Food and Drug Administration FERN MCAP laboratories analyzed approximately 1056 samples over 2 years. Laboratories tested for Salmonella, Listeria, Escherichia coli O157:H7 enterohemorrhagic E. coli, and Shiga toxin-producing strains of E. coli (STEC). Dry and semimoist dog and cat foods purchased from local stores were tested during Phase 1. Raw dog and cat foods, exotic animal feed, and jerky-type treats purchased through the Internet were tested in Phase 2. Of the 480 dry and semimoist samples, only 2 tested positive: 1 for Salmonella and 1 for Listeria greyii. However, of the 576 samples analyzed during Phase 2, 66 samples were positive for Listeria (32 of those were Listeria monocytogenes) and 15 samples positive for Salmonella. These pathogens were isolated from raw foods and jerky-type treats, not the exotic animal dry feeds. This study showed that raw pet foods may harbor food safety pathogens, such as Listeria monocytogenes and Salmonella. Consumers should handle these products carefully, being mindful of the potential risks to human and animal health.

  3. Listeria monocytogenes endophthalmitis - case report and review of risk factors and treatment outcomes.

    Science.gov (United States)

    Bajor, Anna; Luhr, Anke; Brockmann, Dorothee; Suerbaum, Sebastian; Framme, Carsten; Sedlacek, Ludwig

    2016-07-16

    The majority of cases of endophthalmitis are caused by exogenous pathogens; only 5-10 % are of endogenous origin. One cause of these rare cases of endogenous endophthalmitis is Listeria monocytogenes. Twenty-six cases of endophthalmitis due to this pathogen have been published over the last twenty years. The aim of this review is to summarize the main risk factors and common clinical findings of endogenous endophthalmitis due to Listeria monocytogenes. We report on a 62-year-old female presenting with a sterile hypopyon iritis with secondary glaucoma and an underlying rheumatoid disease. In microbiological analysis we identified Listeria monocytogenes. Further we searched through all published cases for typical signs, risk factors, details of medical and surgical treatment and outcome of endogenous endophthalmitis due to this rare pathogen. Ocular symptoms in almost all of these published cases included pain, redness of the eye, and decreased vision. Main clinical features included elevated intraocular pressure and fibrinous anterior chamber reaction, as well as a dark hypopyon. While the infection is typically spread endogenously, neither an exogenous nor endogenous source of infection could be identified in most cases. Immunocompromised patients are at higher risk of being infected than immunocompetent patients. The clinical course of endophthalmitis caused by Listeria monocytogenes had different visual outcomes. In some cases, the infection led to enucleation, blindness, or strong visual loss, whereas most patients showed a tendency of visual improvement during therapy. Early diagnosis and treatment initiation are crucial factors in the outcome of endogenous endophthalmitis caused by Listeria monocytogenes. This possible differential diagnosis should be kept in mind while treating patients with presumable sterile hypopyon and anterior uveitis having a high intraocular pressure. A bacterial source should be considered with a prompt initiation of systemic

  4. Bacteriophage biocontrol of Listeria monocytogenes on soft ripened white mold and red-smear cheeses.

    Science.gov (United States)

    Guenther, Susanne; Loessner, Martin J

    2011-03-01

    Soft-ripened cheeses belong to the type of food most often contaminated with Listeria monocytogenes, and they have been implicated in several outbreaks of listeriosis. Bacteriophages represent an attractive way to combat foodborne pathogens without affecting other properties of the food. We used the broad host range, virulent Listeria phage A511 for control of L. monocytogenes during the production and ripening phases of both types of soft-ripened cheeses, white mold (Camembert-type) cheese, as well as washed-rind cheese with a red-smear surface (Limburger-type). The surfaces of young, unripened cheese were inoculated with 10(1)-10(3) cfu/cm(2)L. monocytogenes strains Scott A (serovar 4b) or CNL 10(3)/2005 (serovar 1/2a). Phage was applied at defined time points thereafter, in single or repeated treatments, at 3 × 10(8) or 1 × 10(9) pfu/cm(2). With Scott A (10(3) cfu/cm(2)) and a single dose of A511 (3 × 10(8) pfu/cm(2)) on camembert-type cheese, viable counts dropped 2.5 logs at the end of the 21 day ripening period. Repeated phage application did not further inhibit the bacteria, whereas a single higher dose (1 × 10(9) pfu/cm(2)) was found to be more effective. On red-smear cheese ripened for 22 days, Listeria counts were down by more than 3 logs. Repeated application of A511 further delayed re-growth of Listeria, but did not affect bacterial counts after 22 days. With lower initial Listeria contamination (10(1)-10(2) cfu/cm(2)), viable counts dropped below the limit of detection, corresponding to more than 6 logs reduction compared to the control. Our data clearly demonstrate the potential of bacteriophage for biocontrol of L. monocytogenes in soft cheese.

  5. Performance of Isfahan North Wastewater Treatment Plant in the Removal of Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    nahid Navijouy

    2013-08-01

    Full Text Available Listeria and in particular Listeria monocytogenes is considered a ubiquitous foodborne pathogen which can lead listeriosis in human and animals. Listeriosis can be serious and may cause meningitis, septicemia and abortion in pregnant women. Although wastewater or sludge may contaminate foods of plant origin, there are no data on occurrence of Listeria spp. in wastewater and sludge in Iran. The purpose of current investigation was to study the occurrence of Listeria spp. in various samples of wastewater and sludge in Isfahan North wastewater treatment plant. Influent, effluent, raw sludge and dried sludge samples were collected from Isfahan North municipal wastewater treatment plant. L. monocytogenes were enumerated by a three–tube most probable number (MPN assay using enrichment Fraser broth. A total of 65 various samples from five step in 13 visits were collected. The presence of Listeria spp. also was determined using USDA procedure. Then, phenotypically identified L. monocytogenes were further confirmed by Polymerase Chain Reaction amplification. L. monocytogenes isolated from 76.9%, 38.5%, 84.6%, 69.2% and 46.2% of influent, effluent, raw sludge, stabilized sludge and dried sludge respectively. The efficiency of wastewater treatment processes, digester tank and drying bed in removal L. monocytogenes were 69.6%, 64.7% and 73.4% respectively. All phenotypically identified L. monocytogenes were further confirmed by Polymerase Chain Reaction. The results of present study have shown that Listeriaspp. and L. monocytogenes in particular, were present in wastewater treatment plant effluents and sludge at high level. The bacteria may spread on agriculture land and contaminate foods of plant origin. This may cause a risk of spreading disease to human and animals.

  6. Caracterização molecular de Listeria monocytogenes oriundas de cortes cárneos bovinos e de abatedouros frigoríficos de bovinos localizados no Distrito Federal, Brasil

    Directory of Open Access Journals (Sweden)

    Joana M. Palma

    Full Text Available RESUMO: Este trabalho teve como objetivo realizar a detecção de cepas de Listeria monocytogenes de cortes cárneos bovinos bem como no ambiente de abatedouros frigoríficos localizados no Distrito Federal, promover a sorotipificação pela reação em cadeia da polimerase (PCR, realizar antibiograma e submeter às cepas à eletroforese de campo pulsado (Pulsed-field gel electrophoresis - PFGE. Foram analisados um total de 125 cortes cárneos bovinos, 45 amostras de swabs de carcaças e 43 amostras de swabs em que foram detectados 13 cepas de Listeria monocytogenes, sendo 11 em cortes cárneos bovinos e 2 swabs de ambiente em um abatedouro frigorifico. Não foram isoladas cepas de swabs de carcaça. Dentre as 13 cepas de Listeria monocytogenes foram encontradas seis cepas do sorotipo 4b, cinco do sorotipo 1/2c e duas cepas do sorotipo 1/2a. Dentre as 11 cepas de L. monocytogenes encontradas em cortes cárneos bovino, uma (9,1% cepa apresentou resistência a eritromicina, outra (9,1% cepa a gentamicina e outra a ciprofloxacina (9,1% e todas as cepas (100% apresentaram resistência ao Ác. Nalidíxico. Das duas (2 cepas oriundas de ralos de abatedouro frigorífico, todas (100% apresentaram resistência ao Ác. Nalidíxico e a sulfonamidas. A análise por eletroforese de campo pulsante (PFGE demonstrou 13 diferentes pulsotipos, em que foram agrupados em 3 diferentes grupos clonais, que coincidentemente se correlacionavam com os 3 diferentes sorotipos encontrados sugerindo uma ampla disseminação desses perfis no Distrito Federal.

  7. Atlas(®) Listeria monocytogenes LmG2 Detection Assay Using Transcription Mediated Amplification to Detect Listeria monocytogenes in Selected Foods and Stainless Steel Surface.

    Science.gov (United States)

    Bres, Vanessa; Yang, Hua; Hsu, Ernie; Ren, Yan; Cheng, Ying; Wisniewski, Michele; Hanhan, Maesa; Zaslavsky, Polina; Noll, Nathan; Weaver, Brett; Campbell, Paul; Reshatoff, Michael; Becker, Michael

    2014-01-01

    The Atlas Listeria monocytogenes LmG2 Detection Assay, developed by Roka Bioscience Inc., was compared to a reference culture method for seven food types (hot dogs, cured ham, deli turkey, chicken salad, vanilla ice cream, frozen chocolate cream pie, and frozen cheese pizza) and one surface (stainless steel, grade 316). A 125 g portion of deli turkey was tested using a 1:4 food:media dilution ratio, and a 25 g portion for all other foods was tested using 1:9 food:media dilution ratio. The enrichment time and media for Roka's method was 24 to 28 h for 25 g food samples and environmental surfaces, and 44 to 48 h for 125 g at 35 ± 2°C in PALCAM broth containing 0.02 g/L nalidixic acid. Comparison of the Atlas Listeria monocytogenes LmG2 Detection Assay to the reference method required an unpaired approach. For each matrix, 20 samples inoculated at a fractional level and five samples inoculated at a high level with a different strain of Listeria monocytogenes were tested by each method. The Atlas Listeria monocytogenes LmG2 Detection Assay was compared to the Official Methods of Analysis of AOAC INTERNATIONAL 993.12 method for dairy products, the U.S. Department of Agriculture, Food Safety and Inspection Service, Microbiology Laboratory Guidebook 8.08 method for ready-to-eat meat and environmental samples, and the U.S. Food and Drug Administration Bacteriological Analytical Manual, Chapter 10 method for frozen foods. In the method developer studies, Roka's method, at 24 h (or 44 h for 125 g food samples), had 126 positives out of 200 total inoculated samples, compared to 102 positives for the reference methods at 48 h. In the independent laboratory studies, vanilla ice cream, deli turkey and stainless steel grade 316 were evaluated. Roka's method, at 24 h (or 44 h for 125 g food samples), had 64 positives out of 75 total inoculated samples compared to 54 positives for the reference methods at 48 h. The Atlas Listeria monocytogenes LmG2 Detection Assay detected all 50

  8. Antimicrobial effect of blueberry (Vaccinium corymbosum L.) extracts against the growth of Listeria monocytogenes and Salmonella Enteritidis

    Science.gov (United States)

    We studied the antimicrobial effects of berry extracts obtained from four cultivars (Elliott, Darrow, Bluecrop and Duke) of blueberry (Vaccinium corymbosum L.) on the growth of Listeria monocytogenes and Salmonella Enteritidis. The minimal inhibitory concentration (MIC) and minimal bactericidal conc...

  9. Detection of Listeria monocytogenes in ready-to-eat food by Step One real-time polymerase chain reaction.

    Science.gov (United States)

    Pochop, Jaroslav; Kačániová, Miroslava; Hleba, Lukáš; Lopasovský, L'ubomír; Bobková, Alica; Zeleňáková, Lucia; Stričík, Michal

    2012-01-01

    The aim of this study was to follow contamination of ready-to-eat food with Listeria monocytogenes by using the Step One real time polymerase chain reaction (PCR). We used the PrepSEQ Rapid Spin Sample Preparation Kit for isolation of DNA and MicroSEQ® Listeria monocytogenes Detection Kit for the real-time PCR performance. In 30 samples of ready-to-eat milk and meat products without incubation we detected strains of Listeria monocytogenes in five samples (swabs). Internal positive control (IPC) was positive in all samples. Our results indicated that the real-time PCR assay developed in this study could sensitively detect Listeria monocytogenes in ready-to-eat food without incubation.

  10. Listeria monocytogenes Meningitis in an Immunosuppressed Patient with Autoimmune Hepatitis and IgG4 Subclass Deficiency

    Directory of Open Access Journals (Sweden)

    Shahin Gaini

    2015-01-01

    Full Text Available A 51-year-old Caucasian woman with Listeria monocytogenes meningitis was treated and discharged after an uncomplicated course. Her medical history included immunosuppressive treatment with prednisolone and azathioprine for autoimmune hepatitis. A diagnostic work-up after the meningitis episode revealed that she had low levels of the IgG4 subclass. To our knowledge, this is the first case report describing a possible association between autoimmune hepatitis and the occurrence of Listeria monocytogenes meningitis, describing a possible association between Listeria monocytogenes meningitis and deficiency of the IgG4 subclass and finally describing a possible association between Listeria monocytogenes meningitis and immunosuppressive therapy with prednisolone and azathioprine.

  11. Evaluation of Listeria Monocytogenes Based Vaccines for HER-2/neu in Mouse Transgenic Models of Breast Cancer

    National Research Council Canada - National Science Library

    Singh, Reshma

    2006-01-01

    ...% of all breast cancers. Five Listeria monocytogenes vaccines have been made consisting of fragments of HER-2/neu that are capable of stopping the growth of transplantable tumors in wild type FVB/N mice and can cause...

  12. Lineage specific recombination rates and microevolution in Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    Nightingale Kendra K

    2008-10-01

    Full Text Available Abstract Background The bacterium Listeria monocytogenes is a saprotroph as well as an opportunistic human foodborne pathogen, which has previously been shown to consist of at least two widespread lineages (termed lineages I and II and an uncommon lineage (lineage III. While some L. monocytogenes strains show evidence for considerable diversification by homologous recombination, our understanding of the contribution of recombination to L. monocytogenes evolution is still limited. We therefore used STRUCTURE and ClonalFrame, two programs that model the effect of recombination, to make inferences about the population structure and different aspects of the recombination process in L. monocytogenes. Analyses were performed using sequences for seven loci (including the house-keeping genes gap, prs, purM and ribC, the stress response gene sigB, and the virulence genes actA and inlA for 195 L. monocytogenes isolates. Results Sequence analyses with ClonalFrame and the Sawyer's test showed that recombination is more prevalent in lineage II than lineage I and is most frequent in two house-keeping genes (ribC and purM and the two virulence genes (actA and inlA. The relative occurrence of recombination versus point mutation is about six times higher in lineage II than in lineage I, which causes a higher genetic variability in lineage II. Unlike lineage I, lineage II represents a genetically heterogeneous population with a relatively high proportion (30% average of genetic material imported from external sources. Phylograms, constructed with correcting for recombination, as well as Tajima's D data suggest that both lineages I and II have suffered a population bottleneck. Conclusion Our study shows that evolutionary lineages within a single bacterial species can differ considerably in the relative contributions of recombination to genetic diversification. Accounting for recombination in phylogenetic studies is critical, and new evolutionary models that

  13. Incidence of Listeria species in bovine, ovine, caprine, camel and water buffalo milk using cultural method and the PCR assay

    OpenAIRE

    Rahimi, Ebrahim; Momtaz, Hassan; Behzadnia, Asma; Baghbadorani, Zeinab Torki

    2014-01-01

    Objective: To determine the prevalence rate of Listeria species in bovine, ovine, caprine, camel and water buffalo milk in Iran. Methods: From September 2010 to December 2011 a total of 260 bulk milk samples including 85 bovine, 37 camel, 34 water buffalo, 56 ovine and 48 caprine bulk milk samples were collected from commercial dairy herds, in Fars and Khuzestan provinces, Iran and were evaluated for the presence of Listeria species using cultural method and the PCR assay. R...

  14. Desenvolvimento de material de referência para microbiologia de alimentos contendo Listeria monocytogenes em matriz queijo

    Directory of Open Access Journals (Sweden)

    Marcelo Luiz Lima Brandão

    2013-10-01

    Full Text Available A NBR ISO/IEC 17025:2005, uma das normas mais utilizadas em laboratórios de ensaio, descreve como um de seus critérios para a garantia da qualidade dos resultados analíticos a participação periódica dos laboratórios em ensaios de proficiência (EP. Os analitos, utilizados nos EP são materiais de referência (MR provenientes de um mesmo lote, e devem apresentar características de homogeneidade e estabilidade. O objetivo deste estudo foi produzir um MR qualitativo destinado ao ensaio de pesquisa de Listeria monocytogenes em matriz queijo pela técnica de liofilização. Para a produção do MR, foi utilizado como matriz o queijo Minas frescal (QMF ultrafiltrado. A matriz foi distribuída em frascos, contaminada com a bactéria alvo e submetida à liofilização, tendo a sacarose como crioprotetor. O MR produzido foi considerado homogêneo e estável na temperatura de ≤-70°C durante todo o período estudado (10 meses. O material apresentou estabilidade a 4, 25, 30 e 35°C por quatro dias e a -20°C por 48 dias, e os resultados estatísticos indicam tendência à estabilidade. Conclui-se que o material apresentou todos os requisitos necessários de um MR de qualidade e poderia ser transportado aos laboratórios participantes de um EP à temperatura máxima de 35°C por até quatro dias, uma vez que os resultados indicaram a manutenção da concentração celular nesse período. Esse foi o primeiro trabalho a descrever uma metodologia de produção de MR contendo L. monocytogenes em matriz queijo.

  15. Potential of chitosan from Mucor rouxxi UCP064 as alternative natural compound to inhibit Listeria monocytogenes Potencial de quitosana de Mucor rouxxi UCP 064 como componente alternativo para inibir Listeria monocytogenes

    Directory of Open Access Journals (Sweden)

    Roberta A. Bento

    2009-09-01

    Full Text Available Listeria monocytogenes is widely distributed in nature and the infection listeriosis is recognized as a potential threat for human health because of its mortality rate. The objective of this study was to evaluate the growth profile and chitosan production by Mucor rouxxi UCP 064 grown in yam bean (Pachyrhizus erosus L. Urban medium. It was also to assess the anti-L. monocytogenes efficacy of the obtained chitosan. Higher values of biomass of M. rouxxi (16.9 g.L¹ and best yield of chitosan (62 mg.g-1 were found after 48 h of cultivation. Residual glucose and nitrogen in the growth media were 4.1 and 0.02 g.L¹ after 96 h, respectively. Obtained chitosan presented 85 % of degree of deacetylation and 2.60 x 10(4 g.mol-1of viscosimetric molecular weight. Minimum Inhibitory Concentration (MIC and Minimum Bactericidal Concentration (MBC values of chitosan against L. monocytogenes ATCC 7644 were, respectively, 2.5 and 5.0 mg.mL-1. At 2.5 and 5.0 mg.mL-1 chitosan caused cidal effect in a maximum time of 4 h. Bacterial count below 2 log cfu.mL-1were found from 2 h onwards and no recovery in bacterial growth was noted in the remainder period. These results show the biotechnological potential of yam bean medium for chitosan production by Mucor rouxxi and support the possible rational use of chitosan from fungi as natural antimicrobial to control L. monocytogenes.Listeria monocytogenes apresentase como um microrganismo amplamente distribuído na natureza, sendo que a infecção listeriose é reconhecida como uma potencial ameaça a saúde humana devido a sua taxa de mortalidade. O objetivo deste estudo foi avaliar o perfil de crescimento e de produção de quitosana por Mucor rouxxi UCP 064 cultivado em meio jacatupé (Pachyrhizus erosus L. Urban, bem como avaliar a eficácia anti-L. monocytogenes da quitosana produzida com vistas a uma possível aplicação em alimentos. Os mais elevados valores de biomassa de M. rouxxi (16,9 g.L¹ e o maior rendimento na

  16. Antibiotics Susceptibility Profile of Listeria Species Isolated from Poultry Wastes and Fishpond Water from Private and Institutional Farms in Ibadan, Nigeria

    OpenAIRE

    Olutayo Israel Falodun; Moturayo Janet Amusan

    2017-01-01

    Introduction: Untreated waste being discharged into the environment due to proliferation of poultry and fish farms can constitute a public health threat to human. Listeria, an emerging pathogen is commonly associated with food. This study aimed at determining the antibiotic resistant pattern of Listeria species isolated from poultry droppings and fish pond water in Ibadan. Materials and Methods: Poultry waste and fishpond water samples were collected between April and July, 2016. Listeria...

  17. Confirmed low prevalence of Listeria mastitis in she-camel milk delivers a safe, alternative milk for human consumption.

    Science.gov (United States)

    Osman, Kamelia M; Samir, Ahmed; Orabi, Ahmed; Zolnikov, Tara Rava

    2014-02-01

    She-camel milk is an alternative solution for people allergic to milk; unfortunately, potential harmful bacteria have not been tested in she-camel milk. Listeria monocytogenes is one harmful bacterium that causes adverse health effects if chronically or acutely ingested by humans. The purpose of this study was to estimate the prevalence, characterize the phenotypic, genetic characterization, virulence factors, and antibiopotential harmful bacteria resistance profile of Listeria isolated from the milk of she-camel. Udder milk samples were collected from 100 she-camels and screened for mastitis using the California mastitis test (46 healthy female camels, 24 subclinical mastitic animals and 30 clinical mastitic animals). Samples were then examined for the presence of pathogenic Listeria spp; if located, the isolation of Listeria was completed using the International Organization for Standards technique to test for pathogenicity. The isolates were subjected to PCR assay for virulence-associated genes. Listeria spp. were isolated from 4% of samples and only 1.0% was confirmed as L. monocytogenes. The results of this study provide evidence for the low prevalence of intramammary Listeria infection; additionally, this study concludes she-camel milk in healthy camels milked and harvested in proper hygienic conditions may be used as alternative milk for human consumption. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Irrigation Is Significantly Associated with an Increased Prevalence of Listeria monocytogenes in Produce Production Environments in New York State.

    Science.gov (United States)

    Weller, Daniel; Wiedmann, Martin; Strawn, Laura K

    2015-06-01

    Environmental (i.e., meteorological and landscape) factors and management practices can affect the prevalence of foodborne pathogens in produce production environments. This study was conducted to determine the prevalence of Listeria monocytogenes, Listeria species (including L. monocytogenes), Salmonella, and Shiga toxin-producing Escherichia coli (STEC) in produce production environments and to identify environmental factors and management practices associated with their isolation. Ten produce farms in New York State were sampled during a 6-week period in 2010, and 124 georeferenced samples (80 terrestrial, 33 water, and 11 fecal) were collected. L. monocytogenes, Listeria spp., Salmonella, and STEC were detected in 16, 44, 4, and 5% of terrestrial samples, 30, 58, 12, and 3% of water samples, and 45, 45, 27, and 9% of fecal samples, respectively. Environmental factors and management practices were evaluated for their association with terrestrial samples positive for L. monocytogenes or other Listeria species by univariate logistic regression; analysis was not conducted for Salmonella or STEC because the number of samples positive for these pathogens was low. Although univariate analysis identified associations between isolation of L. monocytogenes or Listeria spp. from terrestrial samples and various water-related factors (e.g., proximity to wetlands and precipitation), multivariate analysis revealed that only irrigation within 3 days of sample collection was significantly associated with isolation of L. monocytogenes (odds ratio = 39) and Listeria spp. (odds ratio = 5) from terrestrial samples. These findings suggest that intervention at the irrigation level may reduce the risk of produce contamination.

  19. Listeria monocytogenes contamination of the environment and surfaces of the equipment in the meat processing facilities in republic of Macedonia

    Directory of Open Access Journals (Sweden)

    Dean Jankuloski

    2007-11-01

    Full Text Available Listeria monocytogenes contamination of the environment and surfaces of the equipment was examined in seven meat processing facilities. Up to date prevalence of this foodborn pathogen in meat processing facilities facilities in Republic of Macedonia was unknown. Biofilms are composed from food spoilage microorganisms and food born pathogens. They are located on the surfaces of the equipment that come in contact with food and in facilities environment. Microorganisms in biofilm presenting micro eco system and are source of dissemination and contamination of food born pathogens in final meat products. During the preparation of this study we have covered a 7 meat processing facilities and we took a total of 39 swabs from surfaces that come in direct or indirect contact with food. Listeria monocytogenes was discovered in 10 (25,64% swabs (locations. Prevalence of other Listeria spp. compared with total number of taken samples was 15 (38,46% Listeria innocua, 3 (7,69% Listeria welshimeri and 1 (2,65% isolate Listeria seeligeri.

  20. VALIDACIÓN DE PCR PARA DETECCIÓN DE Listeria monocytogenes EN CARNES CRUDAS DE RES Y POLLO

    Directory of Open Access Journals (Sweden)

    Kirvis Torres

    2004-12-01

    Full Text Available Listeria monocytogenes es un microorganismo zoonótico emergente en la industria de alimentos, resultando degran interés para la salud pública. El objetivo de este trabajo fue validar la técnica de PCR para la detecciónde este microorganismo en carnes crudas de res y pollo. El procedimiento de extracción de ADN fue realizadocon lisozima, proteinasa K y fenol-cloroformo a partir de muestras contaminadas artificialmente. La especificidadde los cebadores LI1 y U1 fue comprobada por la amplificación de una banda de 938pb correspondiente a unfragmento del ADNr 16S; de igual manera los cebadores LF y LR amplificaron una banda del gen hlyA de750pb; lo que permitió la identificación de género (banda 938pb y especie (banda de 750pb respectivamente.Las cepas de los otros géneros bacterianos ensayados no amplificaron ninguna de las bandas específicas. Ellímite de detección para la PCR fue de 102 y 104 UFC/gr para carnes de res y pollo respectivamente; el «GoldStandard» reportó 102 UFC/ml para ambos alimentos. La comparación de la PCR vs., el método «Gold Standard»reportó en carne de pollo una concordancia observada de 98.43%, una sensibilidad del 96.9%, una especificidadde 100%, un valor predictivo positivo del 100% y un valor predictivo negativo del 97%; para la carne de restodos los parámetros anteriores fueron del 100%. Estos resultados demostraron la factibilidad de la PCR parael control de calidad de carnes crudas de res y pollo.

  1. Listeria spp. E Listeria monocytogenes NA PRODUÇÃO DE SALSICHAS TIPO HOT DOG E HÁBITOS DE CONSUMO

    OpenAIRE

    CESAR, Alessandra Paro Rodrigues

    2008-01-01

    Listeria monocytogenes é uma bactéria Gram-positiva, anaeróbia facultativa, que se multiplica sob temperatura de refrigeração e pode causar listeriose em humanos e outros animais. Amplamente distribuída no ambiente, tem sido isolada de alimentos de origem animal e vegetal associados a surtos de elevada letalidade em diversos países, representando, portanto um patógeno importante para a saúde pública. Produtos prontos para consumo, como embutidos cozidos, entre os quais as salsichas, estão ass...

  2. Detection of Listeria spp. in liquid egg products and in the egg breaking plants environment and tracking of Listeria monocytogenes by PFGE.

    Science.gov (United States)

    Rivoal, Katell; Fablet, Aurore; Courtillon, Céline; Bougeard, Stéphanie; Chemaly, Marianne; Protais, Jocelyne

    2013-08-16

    Human listeriosis, caused by Listeria monocytogenes, is a severe bacterial infection that can lead to meningitis, cerebromeningitis, bacteremia or septicemia, with acute lethality and potentially leading to death. A study has shown that 29.5% of the caged laying hens in France are contaminated by L. monocytogenes (Chemaly et al., 2008). However, very little information regarding egg and egg product contamination is currently available. The objective of this study is to determine the sanitary status of egg products and egg breaking plants in France regarding Listeria spp. and L. monocytogenes contaminations. The sampling scheme performed in five egg breaking plants in Western France during one year have revealed that 8.5% of raw egg products were contaminated by L. monocytogenes. No pasteurized egg products have been shown to be contaminated by L. monocytogenes. However, a high level of contamination by Listeria spp., and particularly by L. innocua, has been shown with 26.2% and 1.8% of raw and pasteurized egg products contaminated, respectively. This work has also revealed the presence of Listeria spp. and L. monocytogenes in the environment of egg breaking plants with 65.1% and 8.0% of contaminated samples, respectively. The typing of 253 isolates of L. monocytogenes by PFGE using ApaI and AscI enzymes has revealed a high diversity with 46 different pulsotypes and has shown that the raw material is a source of contamination of egg breaking plants. One L. monocytogenes cluster was dominant in the 5 egg-breaking plants during the four seasons studied. The issue of which strains are better adapted to egg products must be considered and studied in depth by comparing them to pulsotypes from strains of other chains. However, the traceability of L. monocytogenes in plants during the various seasons has also made it possible to highlight the presence of strains that are specific to egg breaking plants. The study of cleaning and disinfection methods in these plants as well

  3. The Arsenic Resistance-Associated Listeria Genomic Island LGI2 Exhibits Sequence and Integration Site Diversity and a Propensity for Three Listeria monocytogenes Clones with Enhanced Virulence.

    Science.gov (United States)

    Lee, Sangmi; Ward, Todd J; Jima, Dereje D; Parsons, Cameron; Kathariou, Sophia

    2017-11-01

    In the foodborne pathogen Listeria monocytogenes , arsenic resistance is encountered primarily in serotype 4b clones considered to have enhanced virulence and is associated with an arsenic resistance gene cluster within a 35-kb chromosomal region, Listeria genomic island 2 (LGI2). LGI2 was first identified in strain Scott A and includes genes putatively involved in arsenic and cadmium resistance, DNA integration, conjugation, and pathogenicity. However, the genomic localization and sequence content of LGI2 remain poorly characterized. Here we investigated 85 arsenic-resistant L. monocytogenes strains, mostly of serotype 4b. All but one of the 70 serotype 4b strains belonged to clonal complex 1 (CC1), CC2, and CC4, three major clones associated with enhanced virulence. PCR analysis suggested that 53 strains (62.4%) harbored an island highly similar to LGI2 of Scott A, frequently (42/53) in the same location as Scott A ( LMOf2365_2257 homolog). Random-primed PCR and whole-genome sequencing revealed seven novel insertion sites, mostly internal to chromosomal coding sequences, among strains harboring LGI2 outside the LMOf2365_2257 homolog. Interestingly, many CC1 strains harbored a noticeably diversified LGI2 (LGI2-1) in a unique location ( LMOf2365_0902 homolog) and with a novel additional gene. With few exceptions, the tested LGI2 genes were not detected in arsenic-resistant strains of serogroup 1/2, which instead often harbored a Tn 554 -associated arsenic resistance determinant not encountered in serotype 4b. These findings indicate that in L. monocytogenes , LGI2 has a propensity for certain serotype 4b clones, exhibits content diversity, and is highly promiscuous, suggesting an ability to mobilize various accessory genes into diverse chromosomal loci. IMPORTANCE Listeria monocytogenes is widely distributed in the environment and causes listeriosis, a foodborne disease with high mortality and morbidity. Arsenic and other heavy metals can powerfully shape the

  4. [Survey of the presence of Listeria monocytogenes in meat products sold in retail].

    Science.gov (United States)

    Langiano, E; Lanni, L; Atrei, P; De Vito, E

    2007-01-01

    The present study evaluates the presence of Listeria spp and particularly of L. monocytogenes in bovine, pork and poultry meats sold by retail in supermarkets and butchers in the city of Cassino. The sensibility to the antibiotics mostly used in the veterinary practice has been tested on the isolated strains. The different species of Listeria have shown a considerable variation of isolation based on the meat's typology and on the different store's provenance. Moreover our results show greater degree of contamination than the data currently available the Italian literature. In our study poultry meat is the most contaminated one. We can assert that omissions and poor caring errors in the manipulation and conservation of meat expose the customer to an even higher risk of infection.

  5. Detection of Listeria species in Gamma irradiated Fishes during Storage periods

    International Nuclear Information System (INIS)

    Mohamed, W.S.

    2011-01-01

    This investigation was carried out to detect the post irradiation recovery and growth of Listeria species encountered in frozen whole Tilapia fishes ,Tilapia fillet and frozen Hamour fillets fishes (-18 degree C) irradiated at 1, 2, 2.5 and 3 kGy. The pathogen was eliminated at a dose of 2.5 kGy of gamma radiation. The presence of the microorganism was monitored for sex months on appropriate selective media. The ability of recovery of the organism from irradiation damage was not influenced by the kind of fish. No increased counts of the organism in irradiated fishes at 2.5 kGy of gamma radiation was noticed during 6 months of freezing storage at -18 degree C. This study also aimed to evaluate the effect of different enrichment procedures on the detection of Listeria species in fishes

  6. Identification of Listeria monocytogenes on Green Mussels (Perna viridis and Cockle Shell (Anadara granosa

    Directory of Open Access Journals (Sweden)

    Winiati Puji Rahayu

    2016-12-01

    Full Text Available Green mussel (Perna viridis and cockle shell (Anadara granosa are one of many sources of animalprotein which is many cultivated in Indonesia because their price is relatively affordable. This study wasconducted to identify the presence of Listeria monocytogenes in 27 samples of green mussels and 3 samplesof cockle shells using real-time Polymerase Chain Reaction (real-time PCR and biochemical methods. Thetarget gene for amplification in real-time PCR was an hlyA gene because this gene was a determinant ofvirulence genes that produce listeriolysin O. Primers used in this study were forward primer DG69 (GTGCCG GGT AAA AGA CCA TA and reverse primer DG74 (CGC CAC TGA GAT ACT AT and fluorescencesignals indicator using SYBR Green I. The results of analysis using real-time PCR were negative Listeriamonocytogenes in all samples, while using biochemical methods there was one of 30 samples contaminatedby Listeria welshimeri.

  7. Listeria monocytogenes in poultry and poultry products: Epidemiological investigations in seven Danish abattoirs

    DEFF Research Database (Denmark)

    Ojeniyi, B.; Wegener, Henrik Caspar; Jensen, N.E.

    1996-01-01

    Listeria monocytogenes was isolated from 11/236 (4 . 7%) caecal samples from parent flocks, providing broilers to the abattoirs investigated. Caecal samples from 2078 broilers representing 90 randomly selected broiler flocks were negative for L. monocytogenes. A total of 3080 samples from seven...... abattoirs including poultry processing line samples, and final products were also examined for L. monocytogenes. Listeria monocytogenes was isolated in 0 . 3% to 18 . 7% of the samples collected in the different abattoirs. Epidemiological typing of 247 L. monocytogenes isolates, including serotyping, phage...... isolates of L. monocytogenes since only 120/247 (48 . 6%) isolates were typable by phage typing and 230/247 (93 . 1%) L. monocytogenes belonged to serotype 01 while 6/247 (2 . 4%) belonged to 04. The discovery of a few dominating clones in each abattoir might indicate an endemic occurrence of L...

  8. RNA- and protein-mediated control of Listeria monocytogenes virulence gene expression

    Science.gov (United States)

    Lebreton, Alice; Cossart, Pascale

    2017-01-01

    ABSTRACT The model opportunistic pathogen Listeria monocytogenes has been the object of extensive research, aiming at understanding its ability to colonize diverse environmental niches and animal hosts. Bacterial transcriptomes in various conditions reflect this efficient adaptability. We review here our current knowledge of the mechanisms allowing L. monocytogenes to respond to environmental changes and trigger pathogenicity, with a special focus on RNA-mediated control of gene expression. We highlight how these studies have brought novel concepts in prokaryotic gene regulation, such as the ‘excludon’ where the 5′-UTR of a messenger also acts as an antisense regulator of an operon transcribed in opposite orientation, or the notion that riboswitches can regulate non-coding RNAs to integrate complex metabolic stimuli into regulatory networks. Overall, the Listeria model exemplifies that fine RNA tuners act together with master regulatory proteins to orchestrate appropriate transcriptional programmes. PMID:27217337

  9. Bacteriophage amplification assay for detection of Listeria spp. using virucidal laser treatment

    Directory of Open Access Journals (Sweden)

    I.C. Oliveira

    2012-09-01

    Full Text Available A protocol for the bacteriophage amplification technique was developed for quantitative detection of viable Listeria monocytogenes cells using the A511 listeriophage with plaque formation as the end-point assay. Laser and toluidine blue O (TBO were employed as selective virucidal treatment for destruction of exogenous bacteriophage. Laser and TBO can bring a total reduction in titer phage (ca. 10(8 pfu/mL without affecting the viability of L. monocytogenes cells. Artificially inoculated skimmed milk revealed mean populations of the bacteria as low as between 13 cfu/mL (1.11 log cfu/mL, after a 10-h assay duration. Virucidal laser treatment demonstrated better protection of Listeria cells than the other agents previously tested. The protocol was faster and easier to perform than standard procedures. This protocol constitutes an alternative for rapid, sensitive and quantitative detection of L. monocytogenes.

  10. Listeria monocytogenes Growth Kinetics in Milkshakes Made from Naturally and Artificially Contaminated Ice Cream

    OpenAIRE

    Salazar, Joelle K.; Bathija, Vriddi M.; Carstens, Christina K.; Narula, Sartaj S.; Shazer, Arlette; Stewart, Diana; Tortorello, Mary Lou

    2018-01-01

    This study assessed the growth of Listeria monocytogenes in milkshakes made using the process-contaminated ice cream associated with a listeriosis outbreak in comparison to milkshakes made with artificially contaminated ice cream. For all temperatures, growth kinetics including growth rates, lag phases, maximum populations, and population increases were determined for the naturally and artificially derived contaminants at 5, 10, 15, and 25°C storage for 144 h. The artificially inoculated L. m...

  11. 2-deoxy-D-glucose-induced metabolic stress enhances resistance to Listeria monocytogenes infection in mice

    Science.gov (United States)

    Miller, E. S.; Bates, R. A.; Koebel, D. A.; Fuchs, B. B.; Sonnenfeld, G.

    1998-01-01

    Exposure to different forms of psychological and physiological stress can elicit a host stress response, which alters normal parameters of neuroendocrine homeostasis. The present study evaluated the influence of the metabolic stressor 2-deoxy-D-glucose (2-DG; a glucose analog, which when administered to rodents, induces acute periods of metabolic stress) on the capacity of mice to resist infection with the facultative intracellular bacterial pathogen Listeria monocytogenes. Female BDF1 mice were injected with 2-DG (500 mg/kg b. wt.) once every 48 h prior to, concurrent with, or after the onset of a sublethal dose of virulent L. monocytogenes. Kinetics of bacterial growth in mice were not altered if 2-DG was applied concurrently or after the start of the infection. In contrast, mice exposed to 2-DG prior to infection demonstrated an enhanced resistance to the listeria challenge. The enhanced bacterial clearance in vivo could not be explained by 2-DG exerting a toxic effect on the listeria, based on the results of two experiments. First, 2-DG did not inhibit listeria replication in trypticase soy broth. Second, replication of L. monocytogenes was not inhibited in bone marrow-derived macrophage cultures exposed to 2-DG. Production of neopterin and lysozyme, indicators of macrophage activation, were enhanced following exposure to 2-DG, which correlated with the increased resistance to L. monocytogenes. These results support the contention that the host response to 2-DG-induced metabolic stress can influence the capacity of the immune system to resist infection by certain classes of microbial pathogens.

  12. Listeria abortions in sheep on the Accra plains: A case report | Osei ...

    African Journals Online (AJOL)

    Listeria abortions in sheep on the Accra plains: A case report. ... Fifteen (19.2 per cent) of the 78 ewes were affected. Serological tests ... L'organisme était également isolé des prélèvements vaginaux et préputiaux des moutons à Achimota et Kade, d'où les animaux de reproduction avaient transférés à Pokoase et Achimota.

  13. The prevalence of Listeria spp. food contamination in Iran: A systematic review and meta-analysis.

    Science.gov (United States)

    Hamidiyan, Negar; Salehi-Abargouei, Amin; Rezaei, Zeynab; Dehghani-Tafti, Roohollah; Akrami-Mohajeri, Fateme

    2018-05-01

    Listeria monocytogenes can cause circling disease, encephalitis, meningitis, septicemia, and mastitis in dairy cattle. Contamination from the environment can contaminate foods with Listeria spp. Consumption of foods containing L. monocytogenes can lead to listeriosis in susceptible people (adults with a compromised immune system), pregnant women, and infants. The objective of this study was to determine the prevalence of Listeria spp. and L. monocytogenes in various foods in Iran. We searched PubMed, Science direct, Scopus, Google scholar, and Iranian local databases including Iranian scientific information database and Magiran for relevant studies up to May 2015 using related keywords. In our preliminary search, we retrieved 1344 articles. After removing duplicates and reviewing titles/abstracts, 117 articles were considered, out of which, 75 articles had sufficient quality for inclusion in this meta-analysis. The prevalence of Listeria spp. contamination was about 18.3% in poultry, 8.5% in raw meat, 14.6% in ready-to-eat (RTE) foods, 10% in sea foods, 7.3% in traditional dairy, 3.2% in commercial dairy, and 0.1% in eggs. The findings showed that L. monocytogenes was most prevalent in ready to eat (9.2%), seafood (5.1%), poultry (5%), traditional dairy (4%), raw meat (2.6%), commercial dairy (1.4%), and egg (0.2%), respectively. Furthermore, the presence of L. monocytogenes particularly in RTE foods (that are consumed without further heat processing) and under-cooked products could be a potential risk for public health. So, contamination should be controlled at all levels of the food chain. Copyright © 2018. Published by Elsevier Ltd.

  14. Modeling and predicting the growth boundary of Listeria monocytogenes in lightly preserved seafood

    DEFF Research Database (Denmark)

    Mejlholm, Ole; Dalgaard, Paw

    2007-01-01

    The antimicrobial effect of diacetate and lactate against Listeria monocytogenes was evaluated in challenge tests with vacuum-packaged or modified atmosphere packaged (MAP) cold-smoked salmon, marinated salmon, cold-smoked Greenland halibut, marinated Greenland halibut, and gravad salmon. MAP col...... characteristics required to prevent the growth of L. monocytogenes, thereby making it possible to identify critical control points, and is useful for compliance with the new European Union regulation on ready-to-eat foods (EC 2073/2005)....

  15. Exendin-4 improves resistance to Listeria monocytogenes infection in diabetic db/db mice

    OpenAIRE

    Liu, Hsien Yueh; Chung, Chih-Yao; Yang, Wen-Chin; Liang, Chih-Lung; Wang, Chi-Young; Chang, Chih-Yu; Chang, Cicero Lee-Tian

    2012-01-01

    The incidence of diabetes mellitus is increasing among companion animals. This disease has similar characteristics in both humans and animals. Diabetes is frequently identified as an independent risk factor for infections associated with increased mortality. In the present study, homozygous diabetic (db/db) mice were infected with Listeria (L.) monocytogenes and then treated with the anti-diabetic drug exendin-4, a glucagon-like peptide 1 analogue. In aged db/db mice, decreased CD11b+ macroph...

  16. Novel Listeria Vectors Secreting Gut Flora Altering Agents to Prevent Colon Cancer and Treat Colitis

    Science.gov (United States)

    2016-09-01

    ABSTRACT In the prior period we obtained needed IACUC and biosafety approvals, and developed the backbone Listeria vector needed to produce the B7-H1...Unclassified 19b. TELEPHONE NUMBER (include area code) Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39.18 1 Table of contents...cells Timeline Site 1 Major Task 1 Regulatory approvals Months Subtask 1 IACUC approval Done 1-3 Dr. Curiel Subtask 2 Biosafety approval Done 1-3

  17. Prevalence of Trichomonas, Salmonella, and Listeria in Wild Birds from Southeast Texas.

    Science.gov (United States)

    Brobey, Britni; Kucknoor, Ashwini; Armacost, Jim

    2017-09-01

    Infectious diseases can be a major threat to wildlife populations, especially in human-modified habitats, but infection rates in populations of wild animals are often poorly studied. Trichomonas, Salmonella, and Listeria are all pathogens known to infect birds, but their infection rates in wild bird populations are not well documented. This study documents infection rates of the three pathogens in wild bird populations inhabiting a suburban to rural gradient in Southeast Texas. Various species of wild birds were sampled at five sites in Southeastern Texas representing rural (Birds were captured in mist nets and samples were taken from the oral cavity, crop, and vent to detect the presence of pathogens. Samples were screened for Trichomonas by examining wet mounts under a light microscope, whereas samples were screened for Salmonella and Listeria by examining colonies grown on agar plates. Pathogens detected during the initial screening were further confirmed by PCR and DNA sequencing. Infection rates for Trichomonas, Salmonella, and Listeria were 9%, 17%, and 5%, respectively. The distributions of infection rates across habitats (i.e., rural, exurban, rural) did not differ significantly from the expected null distributions for any of the three pathogens; however, the data suggested some interesting patterns that should be confirmed with a larger dataset. Infection rates for Trichomonas and Salmonella were highest at the suburban sites, whereas the infection rate for Listeria was highest at the rural site. Feeder birds were more likely to be infected by all three pathogens than non-feeder birds. Small sample sizes prevent definitive conclusions regarding variation in infection rates along the suburban to rural gradient, but the results suggest that pathogens followed the predicted patterns. For many of the bird species sampled, this study presents the first report of infection rates by these three pathogens in wild populations.

  18. Compatible solutes: the key to Listeria's success as a versatile gastrointestinal pathogen?

    LENUS (Irish Health Repository)

    Sleator, Roy D

    2010-12-10

    Abstract Recently we reported a role for compatible solute uptake in mediating bile tolerance and increased gastrointestinal persistence in the foodborne pathogen Listeria monocytogenes 1 . Herein, we review the evolution in our understanding of how these low molecular weight molecules contribute to growth and survival of the pathogen both inside and outside the body, and how this stress survival mechanism may ultimately be used to target and kill the pathogen.

  19. Occurrence and antimicrobial resistance patterns of Listeria monocytogenes isolated from vegetables

    OpenAIRE

    Byrne,Vanessa de Vasconcelos; Hofer,Ernesto; Vallim,Deyse Christina; Almeida,Rogeria Comastri de Castro

    2016-01-01

    Abstract Although the consumption of fresh and minimally processed vegetables is considered healthy, outbreaks related to the contamination of these products are frequently reported. Among the food-borne pathogens that contaminate vegetables is Listeria monocytogenes, a ubiquitous organism that exhibits the ability to survive and multiply at refrigerated temperatures. This study aimed to evaluate the occurrence of L. monocytogenes in vegetables as well as the antimicrobial resistance of isola...

  20. The Propeptide of the Metalloprotease of Listeria monocytogenes Controls Compartmentalization of the Zymogen during Intracellular Infection▿

    OpenAIRE

    O'Neil, Heather S.; Forster, Brian M.; Roberts, Kari L.; Chambers, Andrew J.; Bitar, Alan Pavinski; Marquis, Hélène

    2009-01-01

    Integral to the virulence of the intracellular bacterial pathogen Listeria monocytogenes is its metalloprotease (Mpl). Mpl regulates the activity and compartmentalization of the bacterial broad-range phospholipase C (PC-PLC). Mpl is secreted as a proprotein that undergoes intramolecular autocatalysis to release its catalytic domain. In related proteases, the propeptide serves as a folding catalyst and can act either in cis or in trans. Propeptides can also influence protein compartmentalizati...

  1. The Metalloprotease of Listeria monocytogenes Is Activated by Intramolecular Autocatalysis▿ †

    OpenAIRE

    Bitar, Alan Pavinski; Cao, Min; Marquis, Hélène

    2007-01-01

    The metalloprotease (Mpl) of Listeria monocytogenes is a thermolysin-like protease that mediates the maturation of a broad-range phospholipase C, whose function contributes to the ability of this food-borne bacterial pathogen to survive intracellularly. Mpl is made as a proprotein that undergoes maturation by proteolytic cleavage of a large N-terminal prodomain. In this study, we identified the N terminus of mature Mpl and generated Mpl catalytic mutants to investigate the mechanism of Mpl ma...

  2. Phenotypic and Genotypic Characteristics of Listeria monocytogenes Isolated From Dairy and Meat Products

    OpenAIRE

    Bahador; Sadeghi Kalani; Valian; Irajian; Lotfollahi

    2015-01-01

    Background Listeria monocytogenes is a foodborne pathogen and a serious threat to the public health in the world. Consumption of traditional foods such as dairy and meat products can be a major reason for relative abundance and isolation of these bacteria. Objectives The purpose of this study was to determine the phenotypic and genotypic characteristics of L. monocytogenes strains isolated from dairy and meat products. ...

  3. Biofilm formation by Listeria monocytogenes on stainless steel surface and biotransfer potential

    OpenAIRE

    Oliveira,Maíra Maciel Mattos de; Brugnera,Danilo Florisvaldo; Alves,Eduardo; Piccoli,Roberta Hilsdorf

    2010-01-01

    An experimental model was proposed to study biofilm formation by Listeria monocytogenes ATCC 19117 on AISI 304 (#4) stainless steel surface and biotransfer potential during this process. In this model, biofilm formation was conducted on the surface of stainless steel coupons, set on a stainless steel base with 4 divisions, each one supporting 21 coupons. Trypic Soy Broth was used as bacterial growth substrate, with incubation at 37 ?C and stirring of 50 rpm. The number of adhered cells was de...

  4. Effect of surface roughness and stainless steel finish on Listeria monocytogenes attachment and biofilm formation.

    Science.gov (United States)

    Rodriguez, Andres; Autio, Wesley R; McLandsborough, Lynne A

    2008-01-01

    The purpose of this study was to evaluate the effect of surface roughness (Ra) and finish of mechanically polished stainless steel (Ra = 0.26 +/- 0.05, 0.49 +/- 0.10, and 0.69 +/- 0.05 microm) and electropolished stainless steel (Ra = 0.16 +/- 0.06, 0.40 +/- 0.003, and 0.67 +/- 0.02 microm) on Listeria adhesion and biofilm formation. A four-strain cocktail of Listeria monocytogenes was used. Each strain (0.1%) was added to 200 ml of tryptic soy broth (TSB), and coupons were inserted to the mixture for 5 min. For biofilm formation, coupons with adhesive cells were incubated in 1:20 diluted TSB at 32 degrees C for 48 h. The experiment was performed by a randomized block design. Our results show that the level of Listeria present after 48 h of incubation (mean = 7 log CFU/cm2) was significantly higher than after 5 min (mean = 6.0 log CFU/cm2) (P stainless steel (mean = 6.7 log CFU/cm2) (P > 0.05). Listeria initial adhesion (values ranged from 5.9 to 6.1 log CFU/cm2) or biofilm formation (values ranged from 6.9 to 7.2 log CFU/cm2) was not significantly correlated with Ra values (P > 0.05). Image analysis with an atomic force microscope showed that bacteria did not colonize the complete surface after 48 h but were individual cells or grouped in microcolonies that ranged from 5 to 10 microm in diameter and one to three cell layers in thickness. Exopolymeric substances were observed to be associated with the colonies. According to our results, electropolishing stainless steel does not pose a significant advantage for food sanitation over mechanically finished stainless steel.

  5. Assessment of Listeria monocytogenes virulence in the Galleria mellonella insect larvae model.

    Science.gov (United States)

    Rakic Martinez, Mira; Wiedmann, Martin; Ferguson, Martine; Datta, Atin R

    2017-01-01

    Several animal models have been used to understand the molecular basis of the pathogenicity, infectious dose and strain to strain variation of Listeria monocytogenes. The greater wax worm Galleria mellonella, as an alternative model, provides some useful advantages not available with other models and has already been described as suitable for the virulence assessment of various pathogens including L. monocytogenes. The objectives of this study are: 1) confirming the usefulness of this model with a wide panel of Listeria spp. including non-pathogenic L. innocua, L. seeligeri, L. welshimeri and animal pathogen L. ivanovii; 2) assessment of virulence of several isogenic in-frame deletion mutants in virulence and stress related genes of L. monocytogenes and 3) virulence assessment of paired food and clinical isolates of L. monocytogenes from 14 major listeriosis outbreaks occurred worldwide between 1980 and 2015. Larvae injected with different concentrations of Listeria were incubated at 37°C and monitored over seven days for time needed to kill 50% of larvae (LT50) and to determine change of bacterial population in G. mellonella, 2 and 24 hours post-inoculation. Non-pathogenic members of Listeria and L. ivanovii showed significantly (P monocytogenes strains. Isogenic mutants of L. monocytogenes with the deletions in prfA, plcA, hly, actA and virR genes, also showed significantly (P monocytogenes strains related to non-invasive (gastroenteritis) outbreaks of listeriosis showed significantly (P < 0.05) lower virulence than isolates of the same serotype obtained from outbreaks with invasive symptoms. The difference, however, was dose and strain- dependent. No significant differences in virulence were observed among the serotype tested in this study.

  6. Diffusion-Weighted Magnetic Resonance Imaging in Rhombencephalitis due to Listeria monocytogenes

    Energy Technology Data Exchange (ETDEWEB)

    Hatipoglu, H.G.; Onbasioglu Gurbuz, M.; Sakman, B.; Yuksel, E. [Dept. of Radiology, Ankara Numune Education and Research Hospital, Ankara (Turkey)

    2007-04-15

    We present diffusion-weighted imaging findings of a case of rhombencephalitis due to Listeria monocytogenes. It is a rare, life-threatening disorder. The diagnosis is difficult by clinical findings only. In this report, we aim to draw attention to the role of conventional and diffusion-weighted magnetic resonance imaging findings. To our knowledge, this is the first case report in the literature with apparent diffusion coefficient values of diseased brain parenchyma.

  7. Combinations of nisin with salt (NaCl) to control Listeria ...

    African Journals Online (AJOL)

    This study evaluated the effect of combinations of nisin with salt (NaCl) to control Listeria monocytogenes on sheep natural sausage casings. Casings were inoculated with 3.0 x 105 cfu/g final inocula of L. monocytogenes, stored at 6°C in different solutions of nisin at 0, 100, 150 and 200 ìg/g. Each combined with salt at 0, 4, ...

  8. Inhibitory Effect of Nisin on Listeria monocytogenes Inoculated into Surimi and Minced Meat

    Directory of Open Access Journals (Sweden)

    Masoud Rezaei

    2012-02-01

    Full Text Available Background & Objective: Listeria monocytogenes has already established as an important food born pathogen which induce listeriosis in human. Use of bacteriocins to provide food safety has been increased dramatically. Nisin has a wide spectrum inhibitory effect than the other bacteriocins and inhibits food-borne pathogens such as L. monocytogenes and many other Gram-positive spoilage microorganisms. The purpose of this study was to investigate the inhibitory effect of Nisin on population of Listeria monocytogenes and the role of changes in food components on the antilisterial properties of Nisin. Materials & Methods: The minced meat and surimi samples were inoculated by 1×104 cfu/g of L. monocytogenes. Then samples exposed to Nisin at the levels of 500 or 1000 IU/g were prepared. All treatments after packaging in plastic bags were kept for 12 days at refrigerator temperature. Samples were cultured on CHROMagarTM Listeria every 2 days and the number of listeria monocytogenes was counted. Results: two different concentrations of Nisin (500 or 1000 IU/g was not able to inhibit L. monocytogenes below the acceptable level for raw food (100 cells per g in minced meat and surimi of silver carp. But the number of bacteria reduces more in fish surimi as compared to the mince meal. Also, antilisterial activity of Nisin was reduced during the storage period. Conclusion: Inhibitory property of Nisin against L. monocytogenes in surimi significantly was higher than the minced (P<0.05. So it is possible the antilisterial properties of Nisin will increase by elimination of some enzymes during processing.

  9. Antibiotic Desensitization Therapy in Secondary Syphilis and Listeria Infection: Case Reports and Review of Desensitization Therapy

    Science.gov (United States)

    Magpantay, Gil; Madar, Cristian S; Hsue, Gunther; Belnap, Conrad

    2011-01-01

    Two adult cases, one of secondary syphilis and one of Listeria monocytogenes bacteremia, in which antibiotic desensitization therapy was utilized to assist treatment of active infection in the face of severe penicillin allergy. Clinical considerations are discussed that led to the decision to employ a formal desensitization procedure. Antibiotic desensitization protocols can facilitate optimal and safe antibiotic therapy in the appropriate clinical setting. PMID:22187514

  10. Listeria monocytogenes isolated in ready-to-eat food in South Bačka region of Vojvodina province, Serbia

    Directory of Open Access Journals (Sweden)

    Gusman Vera

    2014-01-01

    Full Text Available Listeria monocytogenes is pathogenic bacterium that can contaminate food products during and after processing. As ready-to-eat food does not undergo any treatment to ensure its safety before consumption, the risk of foodborne disease must be considered if this pathogen is present in the food. As diseases caused by contaminated food are an important public health problem today, the aim of this study was to determine the prevalence of Listeria monocytogenes in different ready-to-eat food products. In the seven-month period from June 1 to December 31, 2011, a total of 1 380 food samples were examined in the Division of Sanitary Bacteriology, Center for Microbiology, Institute of Public Health of Vojvodina in Novi Sad. A total of 912 samples were analyzed for the presence of Listeria monocytogenes according to ISO 11290-2. The identity of suspected Listeria monocytogenes was confirmed using the VITEK 2 Compact system (BioMerieux, France. Out of 912 samples, Listeria monocytogenes was detected in 18 (1.97%. Listeria monocytogenes was mostly found in cooked meals (in 6 samples out of 18, sandwiches (4 samples and frozen food, such as ice-cream and frozen vegetables (4 samples. It was also found in tofu bread spreads (2 samples, cream cheese (1 sample and cakes (1 sample. The presence of Listeria monocytogenes in some ready-to-eat food could present a public health hazard, particularly to the high-risk population group, because of the high mortality rate associated with listeriosis and the widespread nature of the organism. Monitoring of listeriosis is essential to prevent foodborne outbreaks, and in assessing human health risk in ready-to-eat foods.

  11. Search and molecular identification of two pathogenic bacteria (Salmonella and Listeria) in different food matrices

    International Nuclear Information System (INIS)

    Wislati, Mohamed Amine

    2010-01-01

    A food is a substance consumed in the natural state or after a cooking. The essential role of food is the apport of essential elements in the growth and in the energy needs as well as in the reserves of the body. Foodstuffs may be contaminated by microorganisms such as the viruses, the parasites, the bacteria at the different steps of production, transformation, transport and manipulation being able to engender food collective toxi-infections (T.I.A.C), infections. This study contains a research directed by two pathogenic germs; Listeria and Salmonella as food contaminants, ending at the man's respectively in two diseases: the Listeriosis and the Salmonellosis and the enumeration of the fecal coliform as indicators of lack of hygiene and a contamination of fecal origin. 90 samples of various types and origins are analyzed in the laboratory of biology and molecular microbiology of the (CNSTN) and are identified by Api (Listeria, 20E) and by PCR. Three origins of Listeria and four origins of Salmonella were isolated. Then, the healthiness of various lots was estimated (dairy products, produced meat-based and produced ready to be eaten) according to the plan of interpretation of the result (plan 2 classes) and (plan 3 classes).The obtained results confirm the contamination of our products taken from the market of public consumption. So the strengthen measures of prevention and health control are very important in the food industry.

  12. New perspectives on the gastrointestinal mode of transmission in invasive Listeria monocytogenes infection

    Energy Technology Data Exchange (ETDEWEB)

    Schlech, W.F. III

    1984-01-01

    The route or mechanism of transmission of Listeria monocytogenes from its rural veterinary reservoir to newborn and older human populations has been obscure. Anecdotal reports of milk-borne infection from cows with Listeria mastitis have been published, but intensive investigations of small outbreaks of L. monocytogenes infections in humans have not supported a gastrointestinal mode of infection. Several recent studies, however, strongly suggest this possibility, and case-control studies of epidemic listeriosis in the Canadian Maritime provinces in 1981 documented an association between ingestion of uncooked vegetables and the development of illness (p = 0.02). In that study, coleslaw from a regional producer which was distributed throughout the Maritimes was considered to be the vehicle of transmission. Cabbage, the raw product in the production of coleslaw, was contaminated at a farm prior to arrival at the plant. Contamination occurred through fertilization with raw manure from a flock of sheep known to harbor L. monocytogenes. Therefore, an indirect link was established between Listeria monocytogenes infection of sheep on a cabbage farm and subsequent development of invasive listeriosis in humans. This study supports findings from other epidemiologic studies of human listeriosis and is consistent with results of investigations into the mode of transmission of natural and laboratory-acquired listeriosis in animals. 34 references.

  13. Prevalence of food contamination with Listeria spp. in Kermanshah, Islamic Republic of Iran.

    Science.gov (United States)

    Akya, A; Najafi, A; Moradi, J; Mohebi, Z; Adabagher, S

    2013-05-01

    Listeria monocytogenes is a human pathogen causing serious diseases. We aimed to determine food contamination with Listeria spp. in Kermanshah, Islamic Republic of Iran. Samples (185 dairy, 187 meat products and 158 ready-to-eat foods such as salads) were randomly collected from markets. After processing, samples were cultured in half-Fraser and Fraser broth followed by cultivation on PALCAM and Oxford media. Confirmatory tests including carbohydrate utilization were performed on isolates to determine species. Bacteria were isolated from 66/530 samples (12.5%). Meat products showed the highest (27.2%) and dairy products the lowest (3.8%) contamination rates. L. innocua was found in 56 (10.6%) samples, but L. monocytogenes was only found in 3 samples (0.6%). The results indicate that the rate of contamination with L. monocytogenes, even for ready-to-eat foods, was low but for other Listeria spp., in particular strains of L. innocua, the rate of contamination was higher, suggesting that more control on food sanitation is required.

  14. Evaluation of the MIT RMID 1000 system for the identification of Listeria species.

    Science.gov (United States)

    Ricardi, John; Haavig, David; Cruz, Lasaunta; Paoli, George; Gehring, Andrew

    2010-01-01

    The Micro Imaging Technology (MIT) 1000 Rapid Microbial Identification (RMID) System is a device that uses the principles of light scattering coupled with proprietary algorithms to identify bacteria after being cultured and placed in a vial of filtered water. This specific method is for pure culture identification of Listeria spp. A total of 81 microorganisms (55 isolates) were tested by the MIT 1000 System, of which 25 were Listeria spp. and 30 a variety of other bacterial species. In addition, a total of 406 tests over seven different ruggedness parameters were tested by the MIT 1000 System to determine its flexibility to the specifications stated in the MIT 1000 System User Guide in areas where they might be deviated by a user to shorten the test cycle. Overall, MIT concluded that the MIT 1000 System had an accuracy performance that should certify this Performance Test Method for the identification of Listeria spp. This report discusses the tests performed, results achieved, and conclusions, along with several reference documents to enable a higher understanding of the technology used by the MIT 1000 System.

  15. Listeria spp. in Street-Vended Ready-to-Eat Foods

    Directory of Open Access Journals (Sweden)

    Moustafa El-Shenawy

    2011-01-01

    Full Text Available Street-vended ready-to-eat food sold in Egypt, including sandwiches and dishes of traditional food, was examined for the presence of Listeria species. Out of 576 samples, 24% were found to contain Listeria species. L. monocytogenes and L. innocua were isolated from 57% and 39% of the contaminated samples, respectively. Other Listeria spp. were detected with lower frequency. L. monocytogenes of ≥103 CFU/g were detected in 7% of the total examined samples, which represent 49% of the contaminated food samples (meat, poultry, seafood, dairy products, and products of plant origin. Most of the samples contaminated by L. monocytogenes had high levels of total viable bacterial counts. The results obtained may help to clarify the epidemiology of listeriosis in the country and draw the attention of the decision makers to issue hygienic regulations for food processing industries as well as street vendors in order to ensure safe street-vended ready-to-eat food.

  16. Antimicrobial resistance of Listeria monocytogenes isolated from dairy-based food products.

    Science.gov (United States)

    Harakeh, Steve; Saleh, Imane; Zouhairi, Omar; Baydoun, Elias; Barbour, Elie; Alwan, Nisreen

    2009-06-15

    In this study Listeria monocytogenes (L. monocytogenes) was isolated from three traditionally consumed Lebanese dairy-based food products. One hundred and sixty four samples (45 samples of Baladi cheese, 36 samples of Shankleesh and 83 of Kishk) were collected from the Bekaa Valley in the Northeast region of Lebanon. Suspected Listeria colonies were selected and initially identified by using standard biochemical tests. Initial identification of the positive L. monocytogenes colonies was confirmed at the molecular level by Polymerase Chain Reaction (n=30) and the confirmed isolates were evaluated for their susceptibility to 10 commonly used antimicrobials. All of the 30 isolates were confirmed to be L. monocytogenes yielding a PCR product of approximately 660 base pairs (bp). L. monocytogenes was detected in 26.67%, 13.89% and 7.23% of the Baladi cheese, Shankleesh and Kishk samples, respectively. The highest resistance in L. monocytogenes isolates was noted against oxacillin (93.33%) followed by penicillin (90%). The results provide an indication of the contamination levels of dairy-based foods in Lebanon and highlight the emergence of multi-drug resistant Listeria in the environment.

  17. Effect of enterocin AS-48 in combination with biocides on planktonic and sessile Listeria monocytogenes.

    Science.gov (United States)

    Gómez, Natacha Caballero; Abriouel, Hikmate; Grande, M A José; Pulido, Rubén Pérez; Gálvez, Antonio

    2012-05-01

    Enterocin AS-48 was tested on a cocktail of Listeria monocytogenes strains in planktonic and sessile states, singly or in combination with biocides benzalkonium chloride, cetrimide, hexadecylpyridinium chloride, didecyldimethylammonium bromide, triclosan, poly-(hexamethylen guanidinium) hydrochloride, chlorhexidine, hexachlorophene, and the commercial sanitizers P3 oxonia and P3 topax 66. Combinations of sub-inhibitory bacteriocin concentrations and biocide concentrations 4 to 10-fold lower than their minimum inhibitory concentrations (MIC) completely inhibited growth of the planktonic listeriae. Inactivation of Listeria in biofilms formed on polystyrene microtiter plates required concentrations of enterocin AS-48 greater than 50 μg/ml, and biocide concentrations ten to 100-fold higher. In combination with enterocin AS-48 (25 or 50 μg/ml), microbial inactivation increased remarkably for all biocides except P3 oxonia and P3 topax 66 solutions. Polystyrene microtiter plates conditioned with enterocin solutions (0.5-25 μg/ml) decreased the adherence and biofilm formation of the L. monocytogenes cell cocktail, avoiding biofilm formation for at least 24 h at a bacteriocin concentration of 25 μg/ml. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. An Internalin A Probe-Based Genosensor for Listeria monocytogenes Detection and Differentiation

    Directory of Open Access Journals (Sweden)

    Laura Bifulco

    2013-01-01

    Full Text Available Internalin A (InlA, a protein required for Listeria monocytogenes virulence, is encoded by the inlA gene, which is only found in pathogenic strains of this genus. One of the best ways to detect and confirm the pathogenicity of the strain is the detection of one of the virulence factors produced by the microorganism. This paper focuses on the design of an electrochemical genosensor used to detect the inlA gene in Listeria strains without labelling the target DNA. The electrochemical sensor was obtained by immobilising an inlA gene probe (single-stranded oligonucleotide on the surfaces of screen-printed gold electrodes (Au-SPEs by means of a mercaptan-activated self-assembled monolayer (SAM. The hybridisation reaction occurring on the electrode surface was electrochemically transduced by differential pulse voltammetry (DPV using methylene blue (MB as an indicator. The covalently immobilised single-stranded DNA was able to selectively hybridise to its complementary DNA sequences in solution to form double-stranded DNA on the gold surface. A significant decrease of the peak current of the voltammogram (DPV upon hybridisation of immobilised ssDNA was recorded. Whole DNA samples of L. monocytogenes strains could be discriminated from other nonpathogenic Listeria species DNA with the inlA gene DNA probe genosensor.

  19. Fate of Listeria spp. on parsley leaves grown in laboratory and field cultures.

    Science.gov (United States)

    Dreux, N; Albagnac, C; Carlin, F; Morris, C E; Nguyen-The, C

    2007-11-01

    To investigate the population dynamics of Listeria monocytogenes and Listeria innocua on the aerial surfaces of parsley. Under 100% relative humidity (RH) in laboratory and regardless of the inoculum tested (10(3)-10(8) CFU per leaf), counts of L. monocytogenes EGDe, LO28, LmP60 and L. innocua CIP 80-12 tended towards approx. 10(5) CFU per leaf. Under low RH, Listeria spp. populations declined regardless to the inoculum size (10(4)-10(8) CFU per leaf). L. innocua CIP 80-12 survived slightly better than L. monocytogenes in the laboratory and was used in field cultures. Under field cultures, counts of L. innocua decreased more rapidly than in the laboratory, representing a decrease of 9 log(10) in 2 days in field conditions compared to a decrease of 4.5 log(10) in 8 days in the laboratory. Counts of L. innocua on tunnel parsley cultures were always higher (at least by 100 times) than those on unprotected parsley culture. Even with a high inoculum and under protected conditions (i.e. plastic tunnels), population of L. monocytogenes on the surface of parsley on the field would decrease by several log(10) scales within 2 days. Direct contamination of aerial surfaces of parsley with L. monocytogenes (i.e. through contaminated irrigation water) will not lead to contaminated produce unless it occurs very shortly before harvest.

  20. Rapid detection of Listeria monocytogenes in foods, by a combination of PCR and DNA probe.

    Science.gov (United States)

    Ingianni, A; Floris, M; Palomba, P; Madeddu, M A; Quartuccio, M; Pompei, R

    2001-10-01

    Listeria monocytogenes is a frequent contaminant of water and foods. Its rapid detection is needed before some foods can be prepared for marketing. In this work L. monocytogenes has been searched for in foods, by a combination of polymerase chain reaction (PCR) and a DNA probe. Both PCR and the probe were prepared for recognizing a specific region of the internalin gene, which is responsible for the production of one of the most important pathogenic factors of Listeria. The combined use of PCR and the DNA probe was used for the detection of L. monocytogenes in over 180 environmental and food samples. Several detection methods were compared in this study, namely conventional culture methods; direct PCR; PCR after an enrichment step; a DNA probe alone; a DNA probe after enrichment and another commercially available gene-probe. Finally PCR and the DNA probe were used in series on all the samples collected. When the DNA probe was associated with the PCR, specific and accurate detection of listeria in the samples could be obtained in about a working-day. The present molecular method showed some advantages in terms of rapidity and specificity in comparison to the other aforementioned tests. In addition, it resulted as being easy to handle, even for non-specialized personnel in small diagnostic microbiology laboratories. Copyright 2001 Academic Press.

  1. Listeria monocytogenes behaviour in presence of non-UV-irradiated titanium dioxide nanoparticles.

    Directory of Open Access Journals (Sweden)

    Maria Grazia Ammendolia

    Full Text Available Listeria monocytogenes is the agent of listeriosis, a food-borne disease. It represents a serious problem for the food industry because of its environmental persistence mainly due to its ability to form biofilm on a variety of surfaces. Microrganisms attached on the surfaces are a potential source of contamination for environment and animals and humans. Titanium dioxide nanoparticles (TiO2 NPs are used in food industry in a variety of products and it was reported that daily exposure to these nanomaterials is very high. Anti-listerial activity of TiO2 NPs was investigated only with UV-irradiated nanomaterials, based on generation of reactive oxigen species (ROS with antibacterial effect after UV exposure. Since both Listeria monocytogenes and TiO2 NPs are veicolated with foods, this study explores the interaction between Listeria monocytogenes and non UV-irradiated TiO2 NPs, with special focus on biofilm formation and intestinal cell interaction. Scanning electron microscopy and quantitative measurements of biofilm mass indicate that NPs influence both production and structural architecture of listerial biofilm. Moreover, TiO2 NPs show to interfere with bacterial interaction to intestinal cells. Increased biofilm production due to TiO2 NPs exposure may favour bacterial survival in environment and its transmission to animal and human hosts.

  2. An outbreak of an unusual strain of Listeria monocytogenes infection in North-East Scotland.

    Science.gov (United States)

    Okpo, Emmanuel; Leith, Jayne; Smith-Palmer, Alison; Bell, John; Parks, Duncan; Browning, Fiona; Byers, Lynn; Corrigan, Helen; Webster, Diana; Karcher, Anne M; Murray, Andrew; Storey, Tom

    2015-01-01

    Listeria monocytogenes infection is an important cause of illness and hospitalization in vulnerable individuals. In the present study, we describe a community outbreak of Listeria monocytogenes in the North-East region of Scotland, which was epidemiologically, environmentally and microbiologically linked to a local meat product and ready-to-eat product manufacturer. Infected individuals were interviewed, and an environmental investigation was conducted. Clinical and environmental samples were tested by culture, and isolates were typed by fluorescent amplified fragment length polymorphism (fAFLP). Three cases of Listeria monocytogenes were linked geographically, had the same serotype (1/2a) and were indistinguishable by fAFLP type XII.6. The human, food and environmental isolates were of the same serotype and were indistinguishable by molecular typing. This is the first community outbreak of L. monocytogenes reported in Scotland since the current outbreak surveillance was established in 1996. Epidemiological and laboratory evidence indicated poor hand hygiene, unhygienic practices and cross-contamination throughout the manufacturing process of ready-to-eat foods as a possible cause of the outbreak. More stringent control of commercial food establishments that provide ready-to-eat food and the need to advise specifically vulnerable groups, e.g., pregnant women, of the risk of L. monocytogenes in ready-to-eat food is urgently needed. Copyright © 2015 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  3. Listeria monocytogenes meningitis in the Netherlands, 1985-2014: A nationwide surveillance study.

    Science.gov (United States)

    Koopmans, Merel M; Bijlsma, Merijn W; Brouwer, Matthijs C; van de Beek, Diederik; van der Ende, Arie

    2017-07-01

    Listeria monocytogenes can cause sepsis and meningitis. We report national surveillance data on L. monocytogenes meningitis in the Netherlands, describing incidence changes, genetic epidemiology and fatality rate. We analyzed data from the Netherlands Reference Laboratory of Bacterial Meningitis for cases of L. monocytogenes meningitis. Strains were assessed by serotyping and bacterial population structure by multi-locus sequence typing. A total of 375 cases of Listeria meningitis were identified between 1985 and 2014. Peak incidence rates were observed in neonates (0.61 per 100,000 live births) and older adults (peak at 87 year; 0.53 cases per 100,000 population of the same age). Neonatal listerial meningitis decreased 17-fold from 1.95 per 100,000 live births between 1985 and 1989, to 0.11 per 100,000 live births between 2010 and 2014. Overall case fatality rate was 31%, in a multivariate analysis older age and concomitant bacteremia were associated with mortality (both p listeria meningitis has remained high. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Porøse materialer

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2000-01-01

    Dette undervisningsnotat er en samling af noter, der refererer til den indledende del af kurset Materialmekanik og Porøse materailer på Insitut for Bærende Konstruktiner og Materialer (BKM).......Dette undervisningsnotat er en samling af noter, der refererer til den indledende del af kurset Materialmekanik og Porøse materailer på Insitut for Bærende Konstruktiner og Materialer (BKM)....

  5. Listeria monocytogenes: monitoramento desse perigo biológico na cadeia produtiva de frangos do sul do Rio Grande do Sul Listeria monocytogenes: assessing this microbiological hazard in a poultry productive chain in southern Rio Grande do Sul

    Directory of Open Access Journals (Sweden)

    Élen Silveira Nalério

    2009-09-01

    Full Text Available Listeria monocytogenes é uma bactéria patogênica que se tornou um grande desafio para as indústrias de alimentos, entre elas a de frangos, assim como para os órgãos de vigilância sanitária. Apesar da produção de frangos estar em expansão na região sul do Rio Grande do Sul, não há relatos sobre esse patógeno, dessa forma, objetivou-se avaliar a prevalência de L. monocytogenes e de seus sorotipos nos diversos segmentos dessa cadeia produtiva. Nos aviários isolou-se L. monocytogenes em 2,9% (1/35 das amostras de swabs cloacais, não se isolando o microrganismo em amostras provenientes das camas de aviários. No abatedouro, 11,7% (15/128 das amostras apresentaram contaminação por L. monocytogenes e nos frangos resfriados procedentes do comércio, a prevalência foi de 33,3% (15/45.Observou-se que 51,6% (16/31 das cepas de L. monocytogenes pertenciam ao sorotipo 1/2b; 22,5% (7/31 ao sorotipo 4e; 16,1% (5/31 ao sorotipo 1/2a; 6,4% (2/31 ao sorotipo 4b; e 3,2% (1/31 ao sorotipo 1/2c. Há disseminação de L. monocytogenes na cadeia produtiva de frangos da região sul do Rio Grande do Sul e a presença de sorotipos prevalentes em casos/surtos de listeriose traz preocupação à saúde pública.Listeria monocytogenes is a pathogenic bacterium which has become a huge challenge to the food industries, including the poultry industry, and to the health surveillance agencies. Although poultry production is in expansion in southern of Rio Grande do Sul, Brazil, there are not reports about this pathogen thus this study aimed at assessing the prevalence of L monocytogenes and its serotypes in the several segments of this productive chain. In the broilers flocks L. monocytogenes were isolated in 2.9% (1/35 from cloacal swabs samples. This microorganism was not isolated from broiler houses samples. In the abattoir, 11% of the samples presented L. monocytogenes contamination, and in the chilled chicken from retailers its prevalence was 33.3% (15

  6. Comparison of three Listeria monocytogenes strains in a guinea-pig model simulating food-borne exposure

    DEFF Research Database (Denmark)

    Roldgaard, Bent; Andersen, Jens Bo; Hansen, Tina Beck

    2009-01-01

    Three different Listeria monocytogenes strains, LO28 (a laboratory strain with truncated InlA), 4446 (a clinical isolate) and 7291 (a food isolate), were compared in a guinea-pig model designed to mimic food-borne exposure. The objectives were (1) to verify the applicability of the animal model...... for distinguishing between Listeria with different virulence properties and (2) to explore whether it was possible to reduce the required number of animals by dosing with mixed cultures instead of monocultures. Consistent with in vitro observations of infectivity in Caco-2 cells, faecal densities and presence...... of Listeria strains gave similar results as dosage with a mixture of the three strains; thus, the mixed infection approach was a feasible way to reduce the number of animals needed for determination of listerial virulence....

  7. Las cosas por su nombre

    OpenAIRE

    Storani, Emilia

    2017-01-01

    El artículo propone indagar sobre los modos y diferentes formatos que se utilizan tanto en la escritura como en la lectura, para articular con las luchas por la identidad de género. La Ley de Identidad de Género ha sido un puntapié clave para pensarnos a nosotros mismos culturalmente y para pensar a los demás. Pero, ¿cómo mencionamos, escribimos y leemos las diferentes identidades? La escritura, también es un mundo transformador para quienes bregan por una sociedad más libre y sin prejuicios....

  8. Ptose palpebral causada por Paquidermoperiostose

    Directory of Open Access Journals (Sweden)

    Patricia Regina de Pinho Tavares

    2014-08-01

    Full Text Available A paquidermoperiostose é uma síndrome caracterizada por acometimento cutâneo e ósseo, e em alguns casos ocorre comprometimento palpebral leve. É uma síndrome rara, idiopática ou hereditária, com provável herança autossômica dominante de penetrância variável. Descreve-se o caso de um paciente com ptose grave por paquidermoperiostose elucidando sua fisiopatologia e conduta cirúrgica aplicada.

  9. Diverticulitis yeyunal perforada por enterolito.

    OpenAIRE

    Marenco De la Cuadra, Beatriz; Gomez-Rosado, Juan-Carlos; Capitan-Morales, Luis-Cristobal; Valdés Hernández, Javier; Reyes-lopera, N.J. De los

    2012-01-01

    La diverticulosis yeyunal es una enfermedad adquirida rara. Casi el 60-70% keeps asymptomátic or Con síntomas crónicos inespecíficos, aunque puede presentarse como un abdomen agudo. La perforación debida a enterolitos es una causa extremadamente rara do complicación, y puede producirse por la impactación de ésta contra la pared intestinal. Presentamos caso de un varón de 82 años que acude a urgencias por un dolor súbito abdominal, difuso, con irritación peritoneal, leucocitosis con neutro...

  10. Mortalidad intrahospitalaria por accidente cerebrovascular

    OpenAIRE

    Federico Rodríguez Lucci; Virginia Pujol Lereis; Sebastián Ameriso; Guillermo Povedano; María F. Díaz; Alejandro Hlavnicka; Néstor A. Wainsztein; Sebastián F. Ameriso

    2013-01-01

    La mortalidad global por accidente cerebrovascular (ACV) ha disminuido en las últimas tres décadas, probablemente debido a un mejor control de los factores de riesgo vascular. La mortalidad hospitalaria por ACV ha sido tradicionalmente estimada entre 6 y 14% en la mayoría de las series comunicadas. Sin embargo, los datos de ensayos clínicos recientes sugieren que esta cifra sería sustancialmente menor. Se revisaron datos de pacientes internados con diagnóstico de ACV del Banco de Datos de Str...

  11. Molecular analysis of the iap gene of Listeria monocytogenes isolated from cheeses in Rio Grande do Sul, Brazil Análise molecular do gene iap de Listeria monocytogenes isoladas de queijos no Estado do Rio Grande do Sul, Brasil

    Directory of Open Access Journals (Sweden)

    Jozi Fagundes de Mello

    2008-03-01

    Full Text Available The polymorphic region sequences in the iap gene were analyzed in 25 strains of Listeria monocytogenes isolated from cheeses in the state of Rio Grande do Sul, and compared with reference strains. This investigation distinguished two clusters of L. monocytogenes: I (20 strains and II (5 strains.A seqüência da região polimórfica do gene iap foi analisada em 25 cepas de Listeria monocytogenes isoladas de queijo no Estado do Rio Grande do Sul e comparadas com cepas referências. Esta investigação distinguiu L. monocytogenes em dois grupos: I (20 cepas e II (5 cepas.

  12. Prevalence, identification by a DNA microarray-based assay of human and food isolates Listeria spp. from Tunisia.

    Science.gov (United States)

    Hmaïed, F; Helel, S; Le Berre, V; François, J-M; Leclercq, A; Lecuit, M; Smaoui, H; Kechrid, A; Boudabous, A; Barkallah, I

    2014-02-01

    We aimed at evaluating the prevalence of Listeria species isolated from food samples and characterizing food and human cases isolates. Between 2005 and 2007, one hundred food samples collected in the markets of Tunis were analysed in our study. Five strains of Listeria monocytogenes responsible for human listeriosis isolated in hospital of Tunis were included. Multiplex PCR serogrouping and pulsed field gel electrophoresis (PFGE) applying the enzyme AscI and ApaI were used for the characterization of isolates of L. monocytogenes. We have developed a rapid microarray-based assay to a reliable discrimination of species within the Listeria genus. The prevalence of Listeria spp. in food samples was estimated at 14% by using classical biochemical identification. Two samples were assigned to L. monocytogenes and 12 to L. innocua. DNA microarray allowed unambiguous identification of Listeria species. Our results obtained by microarray-based assay were in accordance with the biochemical identification. The two food L. monocytogenes isolates were assigned to the PCR serogroup IIa (serovar 1/2a). Whereas human L. monocytogenes isolates were of PCR serogroup IVb, (serovars 4b). These isolates present a high similarity in PFGE. Food L. monocytogenes isolates were classified into two different pulsotypes. These pulsotypes were different from that of the five strains responsible for the human cases. We confirmed the presence of Listeria spp. in variety of food samples in Tunis. Increased food and clinical surveillance must be taken into consideration in Tunisia to identify putative infections sources. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  13. Risk analysis of Listeria spp. contamination in two types of ready-to-eat chicken meat products.

    Science.gov (United States)

    Keeratipibul, Suwimon; Lekroengsin, Sumalin

    2009-01-01

    This study was conducted to determine the risk of Listeria contamination in frozen ready-to-eat roasted and steamed chicken meat in a chicken plant in Thailand. Environmental surfaces were divided into three zones. Zone 1 included surfaces in direct contact with products. Zones 2 and 3 included indirect contact surfaces; zone 2 was next to zone 1, and zone 3 was located next to zone 2 and relatively far from the product. A mathematical model for the probability of product contamination after contact with contaminated zone 1 surfaces was established. This model was augmented by an already established model for the probability of Listeria contamination on zone 1 surfaces. Sensitivity analysis revealed that the prevalence of Listeria on zone 1 surfaces before cleaning and sanitizing, production time, and concentration and contact time of sanitizer were correlated with contamination of both products. Alternative risk management measures for reducing the risk of Listeria contamination were developed using sanitizer concentrations of 0.25 to 1.25% (vol/vol), sanitizer contact times of 5 to 20 min, and production times of 5 to 20 h. The plant's risk manager chose a 0.25% (vol/vol) sanitizer concentration, a contact time of 20 min, and a production time of 20 h. After implementation of the selected risk management option, the prevalence of Listeria on roasted and steamed products was reduced by 2.19 and 2.01%, respectively. The prevalence of Listeria in zones 1, 2, and 3 was also reduced by 3.13, 11.24, and 25.66%, respectively.

  14. Detección de Listeria monocytogenes en distintos productos alimenticios y en muestras ambientales de una amplia cadena de supermercados de la ciudad de Bahía Blanca (Argentina Listeria monocytogenes detection in different food products and environmental samples of supermarkets of Bahía Blanca city (Argentine

    Directory of Open Access Journals (Sweden)

    M.A. Marzocca

    2004-12-01

    Full Text Available En el período comprendido entre enero de 2002 y julio de 2003 se realizó este trabajo que consistió en la detección de Listeria monocytogenes en diferentes alimentos: 90 muestras de fiambres cocidos, fraccionados y envasados con diferentes metodologías y 132 muestras de queso de pasta blanda. Estos productos fueron analizados utilizando el criterio presencia-ausencia en 25 g de alimento. L. monocytogenes no se halló ni en los fiambres feteados en las ventas personalizadas ni en las muestras de queso analizadas. Por el contrario, se determinó su presencia en el 10% de los fiambres feteados envasados al vacío y en el 5% de los fiambres trozados envasados al vacío. Estos resultados nos llevaron a incluir la investigación de la presencia de este patógeno en diferentes muestras medioambientales. Para ello se hisoparon 115 puntos incluyendo las líneas de procesamiento, materias primas, utensilios, heladeras. L. monocytogenes se halló en el 13,2% de las muestras analizadas: 5% correspondieron a la sala de fraccionamiento de fiambres y lácteos, 6,7% al frigorífico y 1,5% a los sitios de venta personalizada. Estos resultados indicaron la posible existencia de sitios problemáticos donde el microorganismo tendría probabilidad de formar reservorios, por lo que se extremaron las medidas rutinarias de higiene y desinfección.This work on Listeria monocytogenes detection in different foods was carried out between January 2002 and July 2003. Ninety cold-served cooked meats, sliced and packaged by different methods and 132 pieces of soft cheeses were studied. These products were analyzed using the presence/ausence in 25 g criterion. L. monocytogenes was not found either in foods sliced over the counter or in controlled cheeses, but it was found in 10% of sliced cold-served foods and 5% of cut and cold-served meats vacuum packaged. These results led us to investigate the presence of these pathogen bacteria in different environmental samples. A

  15. DESAJUSTE EDUCATIVO POR REGIONES EN COLOMBIA: ¿COMPETENCIA POR SALARIOS O POR PUESTOS DE TRABAJO?

    Directory of Open Access Journals (Sweden)

    Maribel Castillo Caicedo

    2007-06-01

    Full Text Available Este trabajo aporta una perspectiva del fenómeno de la sobreeducación, entendida como un desajuste por exceso, entre el nivel educativo alcanzado por el individuo y el exigido por el puesto de trabajo en el cual se desempeña; esto se debe a que existe una demanda laboral estrecha de puestos de trabajo para personas calificadas en Colombia. Se analizan las contribuciones empíricas existentes y el debate sobre las mismas; se examinan las teorías que permiten explicar la existencia de un desajuste educativo y se realiza una revisión de la literatura internacional y nacional sobre el tema. Adicionalmente, se plantean una serie de hipótesis para desarrollar un esquema que permita determinar el comportamiento del individuo en el fenómeno de la sobreeducación.

  16. Prevalence of Listeria Species in Ice Creams Sold in The Cities of Kahramanmaraş and Adana

    OpenAIRE

    AKMAN, Deniz; DURAN, Nizami; DIĞRAK, Metin

    2004-01-01

    In this study, the prevalence of Listeria spp. was investigated in the ice cream samples collected from the downtown stores of Kahramanmaras (28 samples) and Adana (30 samples). A total of 58 ice cream samples were analysed by the Food and Drug Administration (FDA) two-stage enrichment techniques. Growth of Listeria spp. was determined in 14 (24.1%) of the samples collected from Kahramanmaras and 10 (17.2%) samples from Adana. The results of the biochemical tests revealed that the bacterial g...

  17. Stochastic modelling of Listeria monocytogenes single cell growth in cottage cheese with mesophilic lactic acid bacteria from aroma producing cultures

    DEFF Research Database (Denmark)

    Østergaard, Nina Bjerre; Christiansen, Lasse Engbo; Dalgaard, Paw

    2015-01-01

    . 2014. Modelling the effect of lactic acid bacteria from starter- and aroma culture on growth of Listeria monocytogenes in cottage cheese. International Journal of Food Microbiology. 188, 15-25]. Growth of L. monocytogenes single cells, using lag time distributions corresponding to three different......A stochastic model was developed for simultaneous growth of low numbers of Listeria monocytogenes and populations of lactic acid bacteria from the aroma producing cultures applied in cottage cheese. During more than two years, different batches of cottage cheese with aroma culture were analysed...

  18. Petiveria alliacea L. extract protects mice against Listeria monocytogenes infection--effects on bone marrow progenitor cells.

    Science.gov (United States)

    Quadros, M R; Souza Brito, A R; Queiroz, M L

    1999-02-01

    In this study we have investigated the effects of Petiveria alliacea on the hematopoietic response of mice infected with Listeria monocytogenes. Our results demonstrate a protective effect of the crude extract of P. alliacea since the survival of the treated/infected was higher than that in the infected group. Moreover, the number of granulocyte/macrophage colonies (CFU-GM) and the serum colony stimulating activity levels were increased in the treated/infected mice in relation to the infected group. These results suggest an immunomodulation of Petiveria alliacea extract on hematopoiesis, which may be responsible, at least in part, for the increased resistance of mice to Listeria monocytogenes infection.

  19. Consanguinidad por isonimia en Salta

    Directory of Open Access Journals (Sweden)

    Albeza, María V.

    2007-01-01

    Full Text Available Se estimó el coeficiente de parentesco por isonimia para localidades de la Puna, Valle Calchaquí y Valle de Lerma, a fin de evaluar diferentes factores evolutivos que podrían estar afectando la composición genética de la población. A partir de los apellidos de las parejas consignadas en fuentes primarias de información, se estimó la isonimia conyugal o marital, el coeficiente total Ft y sus componentes Fr (inbreeding azaroso y Fn (inbreeding no azaroso. De las localidades estudiadas, en la Puna se ha detectado sólo una pareja isónima en una de ellas, en el Valle Calchaquí, tres y ninguna en el Valle de Lerma. Tanto en el Valle Calchaquí como en el de Lerma, se han estimado valores negativos de Ft, y en la Puna se registran los valores más elevados. En las localidades estudiadas no se cumple el supuesto de transmisión patrilineal de apellidos por lo que los valores de Fr y por ende de Ft podrían estar subestimados. Es por ello que sería necesario contar con información desde otras vertientes metodológicas para corroborar, complementar y manejar cuidadosamente el análisis de los datos y las conclusiones que se obtienen.

  20. Celulitis por citomegalovirus Cytomegalovirus cellulitis

    Directory of Open Access Journals (Sweden)

    A. Ruiz Lascano

    2002-12-01

    Full Text Available Las lesiones cutáneas por citomegalovirus (CMV son infrecuentes y a menudo una manifestación tardía de una enfermedad sistémica, que generalmente anuncia un curso fatal. Comunicamos un caso de celulitis por CMV: una mujer de 70 años con trasplante renal efectuado 1 mes antes de la consulta, terapia inmunosupresora con ciclosporina A y metilprednisona. La paciente ingresó por fiebre, dolor e impotencia funcional en pierna derecha. Comprobamos la existencia de una placa de 8 por 4 cm eritematoedematosa. La tratamos con antibióticos sin mejoría, por lo que realizamos un estudio histopatológico de piel que mostró cambios citopáticos compatibles con infección por CMV. Los cultivos bacteriológicos y micológicos fueron negativos. La inmunohistoquímica específica para CMV y el estudio de reacción en cadena de la polimerasa (PCR de la biopsia de piel fueron positivas, al igual que la antigenemia. El tratamiento con ganciclovir produjo la mejoría del cuadro clínico. En la literatura revisada no hemos encontrado la celulitis como manifestación de enfermedad cutánea por CMV.Cutaneous lesions in CMV infection are rare, often a late manifestation of systemic infection, and usually herald a fatal course. A 70 year-old woman received a kidney transplantation one month before consulting and immunosuppressive therapy that included cyclosporine A and methylprednisone. She complained of fever, local pain in her right leg, and an erythematous and swelling plaque. She was treated with intravenous antibiotics without improvement. A skin biopsy was performed and the tissue obtained was sent for bacterial and fungal cultures as well as for histological examination. Cultures were negative. The biopsy showed CMV cytopathic changes. Immunoperoxidase staining was positive for CMV and polymerase chain reaction (PCR testing revealed CMV DNA. She was treated with ganciclovir with resolution of the lesion. CMV cellulitis is a rare cutaneous manifestation

  1. Differentiation of different mixed Listeria strains and also acid-injured, heat-injured, and repaired cells of Listeria monocytogenes using fourier transform infrared spectroscopy.

    Science.gov (United States)

    Nyarko, Esmond; Donnelly, Catherine

    2015-03-01

    Fourier transform infrared (FT-IR) spectroscopy was used to differentiate mixed strains of Listeria monocytogenes and mixed strains of L. monocytogenes and Listeria innocua. FT-IR spectroscopy was also applied to investigate the hypothesis that heat-injured and acid-injured cells would return to their original physiological integrity following repair. Thin smears of cells on infrared slides were prepared from cultures for mixed strains of L. monocytogenes, mixed strains of L. monocytogenes and L. innocua, and each individual strain. Heat-injured and acid-injured cells were prepared by exposing harvested cells of L. monocytogenes strain R2-764 to a temperature of 56 ± 0.2°C for 10 min or lactic acid at pH 3 for 60 min, respectively. Cellular repair involved incubating aliquots of acid-injured and heat-injured cells separately in Trypticase soy broth supplemented with 0.6% yeast extract for 22 to 24 h; bacterial thin smears on infrared slides were prepared for each treatment. Spectral collection was done using 250 scans at a resolution of 4 cm(-1) in the mid-infrared wavelength region. Application of multivariate discriminant analysis to the wavelength region from 1,800 to 900 cm(-1) separated the individual L. monocytogenes strains. Mixed strains of L. monocytogenes and L. monocytogenes cocultured with L. innocua were successfully differentiated from the individual strains when the discriminant analysis was applied. Different mixed strains of L. monocytogenes were also successfully separated when the discriminant analysis was applied. A data set for injury and repair analysis resulted in the separation of acid-injured, heat-injured, and intact cells; repaired cells clustered closer to intact cells when the discriminant analysis (1,800 to 600 cm(-1)) was applied. FT-IR spectroscopy can be used for the rapid source tracking of L. monocytogenes strains because it can differentiate between different mixed strains and individual strains of the pathogen.

  2. Growth of Listeria spp. in shredded cabbage is enhanced by a mild heat treatment.

    Science.gov (United States)

    Ells, Timothy C; Truelstrup Hansen, Lisbeth

    2010-03-01

    Mild thermal processing can enhance the shelf life of cut fruits and vegetables by delaying the onset of spoilage and preserving the organoleptic properties of shredded cabbage. However, food safety issues related to this process have not been fully investigated. Therefore, the survival and growth of Listeria spp. on cabbage treated in this manner was examined. Experimentally, 24 strains of Listeria spp. (including L. monocytogenes) were inoculated onto cut and intact cabbage tissues and stored at 5 degrees C. All strains on intact tissues exhibited a moderate decline in numbers (up to 1.0 log CFU/cm(2)) over the 28-day storage period. Conversely, cut tissue supported growth of most strains during the first 7 to 14 days of incubation with maximum increases of 1.2 log CFU/cm(2). Subsequently, the survival or growth on heat-treated (50 degrees C for 3 min) and untreated shredded cabbage of four L. monocytogenes and four nonpathogenic Listeria spp. strains were compared during storage for 21 days at 5 degrees C. Growth on untreated shred for all strains was similar to the results observed on cut tissue with a maximum increase of approximately 1.0 log CFU/g. However, in the heat-treated cabbage shred all strains displayed a rapid increase in growth (up to 2.5 log CFU/g) during the first 7 days of incubation, which may be indicative of the destruction of an endogenous growth-inhibiting compound within the cabbage. In conclusion, this study shows that mild thermal treatments of cut cabbage may promote pathogen growth if other inimical barriers are not implemented downstream of the thermal treatment.

  3. DETECTION AND CHARACTERISATION OF LISTERIA ISOLATES COLLECTED ALONG THE GORGONZOLA PDO PRODUCTION CHAIN

    Directory of Open Access Journals (Sweden)

    D. Nucera

    2011-08-01

    Full Text Available Considering that Listeria monocytogenes represents a concern in the production of Gorgonzola PDO cheese, this study was aimed to investigate the presence of Listeria along one Gorgonzola PDO production chain. L. monocytogenes subtype diversity was also investigated in order to identify possible reservoirs and dissemination routes. One dairy plant and its conferring farms (N=20 were selected and samples were collected in 4 visits in order to investigate seasonal variability. In each of them, producer tank milk (N=80, Gorgonzola producer tanks (N=12, Gorgonzola producer environmental samples (N=108 were collected, for a total of 200 samples. L. innocua was isolated from 3 milk samples (4%; L. monocytogenes alone was detected in 3 environmental samples (16% and L. innocua in 11 (58%. Both species were present in 5 samples. All Listeria strains isolated were typed through ERIC and REP PCRs. For each samples, if possible 5 colonies were selected for typing, for a total of 76 isolates. The analyses allowed the differentiation of L. monocytogenes and L. innocua in 9 and 7 PCR profiles (P, respectively. The former showed an overall similarity value of 75% and the latter of 81%. P1 (N=3 of L. monocytogenes was present in multiple sources (ripening surfaces and salting equipment and P5 (N=6 in different sampling rounds (January and June 2009. P1 (N=25 and P2 (N=15 of L. innocua were found in multiple sources (performing equipment, ripening surfaces, salting equipment, moving carts and in multiple sample rounds (P1: May 2008, January and June 2009; P2: June and October 2009. The presence of a few highly similar strains of L. monocytogenes in the production chain, as suggested by the profiles retrieved from different sources/sampling rounds, indicates the presence of persistent and niche-adapted strains. However, no profile was shared between raw milk and environmental samples, suggesting that the plant environment, not the incoming raw milk, is the source

  4. Electrochemical genosensing of Salmonella, Listeria and Escherichia coli on silica magnetic particles

    International Nuclear Information System (INIS)

    Liébana, Susana; Brandão, Delfina; Cortés, Pilar; Campoy, Susana; Alegret, Salvador; Pividori, María Isabel

    2016-01-01

    A magneto-genosensing approach for the detection of the three most common pathogenic bacteria in food safety, such as Salmonella, Listeria and Escherichia coli is presented. The methodology is based on the detection of the tagged amplified DNA obtained by single-tagging PCR with a set of specific primers for each pathogen, followed by electrochemical magneto-genosensing on silica magnetic particles. A set of primers were selected for the amplification of the invA (278 bp), prfA (217 bp) and eaeA (151 bp) being one of the primers for each set tagged with fluorescein, biotin and digoxigenin coding for Salmonella enterica, Listeria monocytogenes and E. coli, respectively. The single-tagged amplicons were then immobilized on silica MPs based on the nucleic acid-binding properties of silica particles in the presence of the chaotropic agent as guanidinium thiocyanate. The assessment of the silica MPs as a platform for electrochemical magneto-genosensing is described, including the main parameters to selectively attach longer dsDNA fragments instead of shorter ssDNA primers based on their negative charge density of the sugar-phosphate backbone. This approach resulted to be a promising detection tool with sensing features of rapidity and sensitivity very suitable to be implemented on DNA biosensors and microfluidic platforms. - Highlights: • Silica magnetic particles were used for the first time as carrier in electrochemical magneto-genosensing of single-tagged amplicons. • They demonstrated to be a robust platform for the electrochemical detection of PCR products. • Differential adsorption properties for longer dsDNA amplicon incorporating the tagging primers over shorter ssDNA tagged primers were observed due to the negative charge density. • Electrochemical magneto-genosensing of Salmonella enterica, Listeria monocytogenes and Escherichia coli was successfully performed.

  5. An insight into the isolation, enumeration and molecular detection of Listeria monocytogenes in food

    Directory of Open Access Journals (Sweden)

    Jodi Woan-Fei Law

    2015-11-01

    Full Text Available Listeria monocytogenes, a foodborne pathogen that can cause listeriosis through the consumption of food contaminated with this pathogen. The ability of L. monocytogenes to survive in extreme conditions and cause food contaminations have become a major concern. Hence, routine microbiological food testing is necessary to prevent food contamination and outbreaks of foodborne illness. This review provides insight into the methods for cultural detection, enumeration and molecular identification of L. monocytogenes in various food samples. There are a number of enrichment and plating media that can be used for the isolation of L. monocytogenes from food samples. Enrichment media such as buffered Listeria Enrichment Broth (BLEB, Fraser broth and University of Vermont Medium (UVM Listeria enrichment broth are recommended by regulatory agencies such as FDA-BAM, USDA-FSIS and ISO. Many plating media are available for the isolation of L. monocytogenes, for instance, PALCAM, Oxford and other chromogenic media. Besides, reference methods like FDA-BAM, ISO 11290 method and USDA-FSIS method are usually applied for the cultural detection or enumeration of L. monocytogenes. MPN technique is applied for the enumeration of L. monocytogenes in the case of low level contamination. Molecular methods including polymerase chain reaction (PCR, multiplex polymerase chain reaction (mPCR, real-time/quantitative polymerase chain reaction (qPCR, nucleic acid sequence-based amplification (NASBA, loop-mediated isothermal amplification (LAMP, DNA microarray and Next Generation Sequencing (NGS technology for the detection and identification of L. monocytogenes are discussed in this review. Overall, molecular methods are rapid, sensitive, specific, time- and labour-saving. In future, there are chances for the development of new techniques for the detection and identification of foodborne with improved features.

  6. Agonist anti-GITR antibody significantly enhances the therapeutic efficacy of Listeria monocytogenes-based immunotherapy.

    Science.gov (United States)

    Shrimali, Rajeev; Ahmad, Shamim; Berrong, Zuzana; Okoev, Grigori; Matevosyan, Adelaida; Razavi, Ghazaleh Shoja E; Petit, Robert; Gupta, Seema; Mkrtichyan, Mikayel; Khleif, Samir N

    2017-08-15

    We previously demonstrated that in addition to generating an antigen-specific immune response, Listeria monocytogenes (Lm)-based immunotherapy significantly reduces the ratio of regulatory T cells (Tregs)/CD4 + and myeloid-derived suppressor cells (MDSCs) in the tumor microenvironment. Since Lm-based immunotherapy is able to inhibit the immune suppressive environment, we hypothesized that combining this treatment with agonist antibody to a co-stimulatory receptor that would further boost the effector arm of immunity will result in significant improvement of anti-tumor efficacy of treatment. Here we tested the immune and therapeutic efficacy of Listeria-based immunotherapy combination with agonist antibody to glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR) in TC-1 mouse tumor model. We evaluated the potency of combination on tumor growth and survival of treated animals and profiled tumor microenvironment for effector and suppressor cell populations. We demonstrate that combination of Listeria-based immunotherapy with agonist antibody to GITR synergizes to improve immune and therapeutic efficacy of treatment in a mouse tumor model. We show that this combinational treatment leads to significant inhibition of tumor-growth, prolongs survival and leads to complete regression of established tumors in 60% of treated animals. We determined that this therapeutic benefit of combinational treatment is due to a significant increase in tumor infiltrating effector CD4 + and CD8 + T cells along with a decrease of inhibitory cells. To our knowledge, this is the first study that exploits Lm-based immunotherapy combined with agonist anti-GITR antibody as a potent treatment strategy that simultaneously targets both the effector and suppressor arms of the immune system, leading to significantly improved anti-tumor efficacy. We believe that our findings depicted in this manuscript provide a promising and translatable strategy that can enhance the overall

  7. Electrochemical genosensing of Salmonella, Listeria and Escherichia coli on silica magnetic particles

    Energy Technology Data Exchange (ETDEWEB)

    Liébana, Susana; Brandão, Delfina [Grup de Sensors i Biosensors, Departament de Química, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès (Bellaterra) (Spain); Cortés, Pilar; Campoy, Susana [Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès (Bellaterra) (Spain); Alegret, Salvador [Grup de Sensors i Biosensors, Departament de Química, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès (Bellaterra) (Spain); Pividori, María Isabel, E-mail: Isabel.Pividori@uab.cat [Grup de Sensors i Biosensors, Departament de Química, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès (Bellaterra) (Spain)

    2016-01-21

    A magneto-genosensing approach for the detection of the three most common pathogenic bacteria in food safety, such as Salmonella, Listeria and Escherichia coli is presented. The methodology is based on the detection of the tagged amplified DNA obtained by single-tagging PCR with a set of specific primers for each pathogen, followed by electrochemical magneto-genosensing on silica magnetic particles. A set of primers were selected for the amplification of the invA (278 bp), prfA (217 bp) and eaeA (151 bp) being one of the primers for each set tagged with fluorescein, biotin and digoxigenin coding for Salmonella enterica, Listeria monocytogenes and E. coli, respectively. The single-tagged amplicons were then immobilized on silica MPs based on the nucleic acid-binding properties of silica particles in the presence of the chaotropic agent as guanidinium thiocyanate. The assessment of the silica MPs as a platform for electrochemical magneto-genosensing is described, including the main parameters to selectively attach longer dsDNA fragments instead of shorter ssDNA primers based on their negative charge density of the sugar-phosphate backbone. This approach resulted to be a promising detection tool with sensing features of rapidity and sensitivity very suitable to be implemented on DNA biosensors and microfluidic platforms. - Highlights: • Silica magnetic particles were used for the first time as carrier in electrochemical magneto-genosensing of single-tagged amplicons. • They demonstrated to be a robust platform for the electrochemical detection of PCR products. • Differential adsorption properties for longer dsDNA amplicon incorporating the tagging primers over shorter ssDNA tagged primers were observed due to the negative charge density. • Electrochemical magneto-genosensing of Salmonella enterica, Listeria monocytogenes and Escherichia coli was successfully performed.

  8. An insight into the isolation, enumeration, and molecular detection of Listeria monocytogenes in food

    Science.gov (United States)

    Law, Jodi Woan-Fei; Ab Mutalib, Nurul-Syakima; Chan, Kok-Gan; Lee, Learn-Han

    2015-01-01

    Listeria monocytogenes, a foodborne pathogen that can cause listeriosis through the consumption of food contaminated with this pathogen. The ability of L. monocytogenes to survive in extreme conditions and cause food contaminations have become a major concern. Hence, routine microbiological food testing is necessary to prevent food contamination and outbreaks of foodborne illness. This review provides insight into the methods for cultural detection, enumeration, and molecular identification of L. monocytogenes in various food samples. There are a number of enrichment and plating media that can be used for the isolation of L. monocytogenes from food samples. Enrichment media such as buffered Listeria enrichment broth, Fraser broth, and University of Vermont Medium (UVM) Listeria enrichment broth are recommended by regulatory agencies such as Food and Drug Administration-bacteriological and analytical method (FDA-BAM), US Department of Agriculture-Food and Safety (USDA-FSIS), and International Organization for Standardization (ISO). Many plating media are available for the isolation of L. monocytogenes, for instance, polymyxin acriflavin lithium-chloride ceftazidime aesculin mannitol, Oxford, and other chromogenic media. Besides, reference methods like FDA-BAM, ISO 11290 method, and USDA-FSIS method are usually applied for the cultural detection or enumeration of L. monocytogenes. most probable number technique is applied for the enumeration of L. monocytogenes in the case of low level contamination. Molecular methods including polymerase chain reaction, multiplex polymerase chain reaction, real-time/quantitative polymerase chain reaction, nucleic acid sequence-based amplification, loop-mediated isothermal amplification, DNA microarray, and next generation sequencing technology for the detection and identification of L. monocytogenes are discussed in this review. Overall, molecular methods are rapid, sensitive, specific, time- and labor-saving. In future, there are

  9. Isolation and biochemical and molecular characterization of Listeria monocytogenes in food

    International Nuclear Information System (INIS)

    Helel, Salma

    2008-01-01

    monocytogenes is a Gram-positive bacteria, saprophytic, non-spore. This is an extremely resistant seeds to environmental conditions outside, especially since the cold psychrotrophic. It can contaminate raw vegetables, cooked meals ready for consumption or foods to be stored in the refrigerator, such as cheese or meat. It is the bacteria responsible for listeriosis. It threatens first unborn children, infants, pregnant women, the elderly and people whose immune system is weakened. Strains of Listeria spp isolated from foods (seafood, meat, meat) were first identified at the stage of the genus by classical tests (Gram staining, catalase test, oxidase test and mobility) and stage of the test case by hemolysis, CAMP test and the gallery Api Listeria. Biochemical characterization allowed after a numerical analysis, to assign 100% of isolates to the genus Listeria. Molecular characterization was performed by PCR amplification of genes coding for protein p60 (iap), the listeriolysine O (hly), the Phosphatidylinositol Phospholipase C (PI-PLC plca) Phosphatidylcholine Phospholipase C (plcB). The result showed an amplification of the iap gene of 100% of the hly gene, plca, plcB of 31.81%. This characterization represents an identification of the collection on the genetic level and shows that 31.81% of isolates, is likely to express the genes responsible for virulence factors of L. monocytogenes, to produce listeriolysine O, phospholipase C and Lecithinase. The molecular identification was performed by microarray technique and identified isolates L. September monocytogenes (five original clinical isolates and two food-borne), fourteen L. innocua (of food) and a strain not identified by DNA chip.. (Author)

  10. Manipulation of host membranes by the bacterial pathogens Listeria, Francisella, Shigella and Yersinia.

    Science.gov (United States)

    Pizarro-Cerdá, Javier; Charbit, Alain; Enninga, Jost; Lafont, Frank; Cossart, Pascale

    2016-12-01

    Bacterial pathogens display an impressive arsenal of molecular mechanisms that allow survival in diverse host niches. Subversion of plasma membrane and cytoskeletal functions are common themes associated to infection by both extracellular and intracellular pathogens. Moreover, intracellular pathogens modify the structure/stability of their membrane-bound compartments and escape degradation from phagocytic or autophagic pathways. Here, we review the manipulation of host membranes by Listeria monocytogenes, Francisella tularensis, Shigella flexneri and Yersinia spp. These four bacterial model pathogens exemplify generalized strategies as well as specific features observed during bacterial infection processes. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Subversion of the cytoskeleton by intracellular bacteria: lessons from Listeria, Salmonella, and Vibrio

    Science.gov (United States)

    de Souza Santos, Marcela; Orth, Kim

    2018-01-01

    Summary Entry into host cells and intracellular persistence by invasive bacteria are tightly coupled to the ability of the bacterium to disrupt the eukaryotic cytoskeletal machinery. Herein we review the main strategies used by three intracellular pathogens to harness key modulators of the cytoskeleton. Two of these bacteria, namely Listeria monocytogenes and Salmonella enterica serovar Typhimurium, exhibit quite distinct intracellular lifestyles, and therefore, provide a comprehensive panel for the understanding of the intricate bacteria-cytoskeleton interplay during infections. The emerging intracellular pathogen Vibrio parahaemolyticus is depicted as a developing model for the uncovering of novel mechanisms used to hijack the cytoskeleton. PMID:25440316

  12. Inhibition of Listeria monocytogenes by Lactobacillus bavaricus MN in beef systems at refrigeration temperatures.

    OpenAIRE

    Winkowski, K; Crandall, A D; Montville, T J

    1993-01-01

    The ability of Lactobacillus bavaricus, a meat isolate, to inhibit the growth of three Listeria monocytogenes strains was examined in three beef systems: beef cubes, beef cubes in gravy, and beef cubes in gravy containing glucose. The beef was minimally heat treated, inoculated with L. bavaricus at 10(5) or 10(3) CFU/g and L. monocytogenes at 10(2) CFU/g, vacuum sealed, and stored at 4 or 10 degrees C. The meat samples were monitored for microbial growth, pH, and bacteriocin production. The p...

  13. Prevalence and quantification of Listeria monocytogenes in chicken offal at the retail level in Malaysia.

    Science.gov (United States)

    Kuan, C H; Goh, S G; Loo, Y Y; Chang, W S; Lye, Y L; Puspanadan, S; Tang, J Y H; Nakaguchi, Y; Nishibuchi, M; Mahyudin, N A; Radu, S

    2013-06-01

    A total of 216 chicken offal samples (chicken liver = 72; chicken heart = 72; chicken gizzard = 72) from wet markets and hypermarkets in Selangor, Malaysia, were examined for the presence and density of Listeria monocytogenes by using a combination of the most probable number and PCR method. The prevalence of L. monocytogenes in 216 chicken offal samples examined was 26.39%, and among the positive samples, the chicken gizzard showed the highest percentage at 33.33% compared with chicken liver (25.00%) and chicken heart (20.83%). The microbial load of L. monocytogenes in chicken offal samples ranged from Malaysia.

  14. Prevalence and antimicrobial susceptibility of Listeria monocytogenes on chicken carcasses in Bandung, Indonesia.

    Science.gov (United States)

    Sugiri, Yoni Darmawan; Gölz, Greta; Meeyam, Tongkorn; Baumann, Maximilian P O; Kleer, Josef; Chaisowwong, Warangkhana; Alter, Thomas

    2014-08-01

    This study was conducted to determine the prevalence and quantify the number of Listeria monocytogenes in fresh chicken carcasses sold in traditional markets and supermarkets in Bandung, West Java, Indonesia, and to determine the antimicrobial resistance patterns of the isolated L. monocytogenes strains. The overall prevalence of L. monocytogenes in chicken carcasses was 15.8% (29/184). When comparing samples from traditional markets and supermarkets, no significant difference in the L. monocytogenes prevalence was detectable (15.2 versus 16.3%). Of the samples, 97.3% had L. monocytogenes counts study were grouped into the molecular serogroup IIb, comprising the serovars 1/2b, 3b, and 7.

  15. Assessment of Listeria monocytogenes virulence in the Galleria mellonella insect larvae model.

    Directory of Open Access Journals (Sweden)

    Mira Rakic Martinez

    Full Text Available Several animal models have been used to understand the molecular basis of the pathogenicity, infectious dose and strain to strain variation of Listeria monocytogenes. The greater wax worm Galleria mellonella, as an alternative model, provides some useful advantages not available with other models and has already been described as suitable for the virulence assessment of various pathogens including L. monocytogenes. The objectives of this study are: 1 confirming the usefulness of this model with a wide panel of Listeria spp. including non-pathogenic L. innocua, L. seeligeri, L. welshimeri and animal pathogen L. ivanovii; 2 assessment of virulence of several isogenic in-frame deletion mutants in virulence and stress related genes of L. monocytogenes and 3 virulence assessment of paired food and clinical isolates of L. monocytogenes from 14 major listeriosis outbreaks occurred worldwide between 1980 and 2015. Larvae injected with different concentrations of Listeria were incubated at 37°C and monitored over seven days for time needed to kill 50% of larvae (LT50 and to determine change of bacterial population in G. mellonella, 2 and 24 hours post-inoculation. Non-pathogenic members of Listeria and L. ivanovii showed significantly (P < 0.05 higher LT50 (lower virulence than the wild type L. monocytogenes strains. Isogenic mutants of L. monocytogenes with the deletions in prfA, plcA, hly, actA and virR genes, also showed significantly (P < 0.05 higher LT50 than the wild type strain at the inoculum of 106CFU/larva. Food isolates had significantly (P < 0.05 lower virulence than the paired clinical isolates, at all three inoculum concentrations. L. monocytogenes strains related to non-invasive (gastroenteritis outbreaks of listeriosis showed significantly (P < 0.05 lower virulence than isolates of the same serotype obtained from outbreaks with invasive symptoms. The difference, however, was dose and strain- dependent. No significant differences in

  16. Depletion of proton motive force by nisin in Listeria monocytogenes cells.

    OpenAIRE

    Bruno, M E; Kaiser, A; Montville, T J

    1992-01-01

    The basal proton motive force (PMF) levels and the influence of the bacteriocin nisin on the PMF were determined in Listeria monocytogenes Scott A. In the absence of nisin, the interconversion of the pH gradient (Z delta pH) and the membrane potential (delta psi) led to the maintenance of a fairly constant PMF at -160 mV over the external pH range 5.5 to 7.0. The addition of nisin at concentrations of greater than or equal to 5 micrograms/ml completely dissipated PMF in cells at external pH v...

  17. Behaviour of Listeria monocytogenes in artisanal raw milk Pecorino Umbro cheese: a microbiological challenge test

    Directory of Open Access Journals (Sweden)

    Roberta Ortenzi

    2015-09-01

    Full Text Available In the present study, a microbiological challenge test in artificially contaminated raw milk Pecorino Umbro cheese during cheese-making was carried out. Raw ewe milk was contaminated by a suspension of particular Listeria monocytogenes strains. The number of L. monocytogenes and L. monocytogenes dynamic growth were evaluated during cheese-making and storage. A significant decrease of the viable count of L. monocytogenes was observed during ripening and L. monocytogenes viable count was below the limit of quantification during storage. The results show that the product is unable to support the growth of the pathogen.

  18. Effects of irradiation on bacterial load and Listeria monocytogenes in raw chicken

    International Nuclear Information System (INIS)

    Varabioff, Y.; Mitchell, G.E.; Nottingham, S.M.

    1992-01-01

    After irradiation of chickens to a dose of 2.5 kGy, the decrease in the standard plate count (SPC) was similar in air and in vacuum-packaged chickens. During storage at 4 degrees C for 15 d, the SPC increased progressively in both types of packaged chickens. At the end of the storage period, the SPC was higher in air-packaged chicken than in vacuum-packaged chickens. In irradiated chickens, Listeria monocytogenes was only recovered from the vacuum-packaged chickens after 7 d cold storage. In unirradiated chickens, L. monocytogenes proliferated similarly in both air- and vacuum-packaged chickens

  19. Influence of sublethal concentrations of common disinfectants on expression of virulence genes in Listeria monocytogenes

    DEFF Research Database (Denmark)

    Kastbjerg, Vicky Gaedt; Larsen, M. H.; Gram, Lone

    2010-01-01

    Listeria monocytogenes is a food-borne human pathogen that causes listeriosis, a relatively rare infection with a high fatality rate. The regulation of virulence gene expression is influenced by several environmental factors, and the aim of the present study was to determine how disinfectants use......, such as antibiotic resistance....... by Northern blot analysis. Eleven disinfectants representing four different groups of active components were evaluated in this study. Disinfectants with the same active ingredients had a similar effect on gene expression. Peroxy and chlorine compounds reduced the expression of the virulence genes...

  20. Survival of Listeria monocytogenes on a conveyor belt material with or without antimicrobial additives

    OpenAIRE

    Chaitiemwong, N.; Hazeleger, W.C.; Beumer, R.R.

    2010-01-01

    Survival of Listeria monocytogenes on a conveyor belt material with or without antimicrobial additives, in the absence or presence of food debris from meat, fish and vegetables and at temperatures of 10, 25 and 37 °C was investigated. The pathogen survived best at 10 °C, and better at 25 °C than at 37 °C on both conveyor belt materials. The reduction in the numbers of the pathogen on belt material with antimicrobial additives in the first 6 h at 10 °C was 0.6 log unit, which was significantly...

  1. Desiccation of adhering and biofilm Listeria monocytogenes on stainless steel: Survival and transfer to salmon products

    DEFF Research Database (Denmark)

    Hansen, Lisbeth Truelstrup; Vogel, Birte Fonnesbech

    2011-01-01

    The foodborne bacterial pathogen, Listeria monocytogenes, commonly contaminates foods during processing, where the microorganisms are potentially subjected to low relative humidity (RH) conditions for extended periods of time. The objective of this study was to examine survival during desiccation...... (43% RH and 15°C) of biofilm L. monocytogenes N53-1 cells on stainless steel coupons and to assess subsequent transfer to salmon products. Formation of static biofilm (2days at 100% RH and 15°C) prior to desiccation for 23days significantly (P...

  2. Packaging properties and control of Listeria monocytogenes in bologna by cellulosic films incorporated with pediocin

    Directory of Open Access Journals (Sweden)

    Paula Judith Pérez Espitia

    2013-09-01

    Full Text Available Listeria monocytogenes is a foodborne pathogen, able to survive and proliferate at refrigeration temperatures. As a result, ready-to-eat meat products have been associated with major outbreaks. Producing meat products involves lethal preservation treatments, e.g. thermal treatments. Listeria contamination, however, may be introduced when products are sliced and packaged at retail businesses or delicatessens. In Brazil, sliced bologna is very popular at retail markets. After slicing, however, bologna has a short shelf-life. The aim of this work was to study the effects of pediocin incorporation on the load at break, water vapor permeability rate and structure, by microscopic analysis, of antimicrobial cellulosic packaging. The potential application of the developed packaging for the preservation of bologna and inhibition of Listeria biofilm formation was also studied. Cellulosic antimicrobial packaging films were produced with cellulose acetate and acetone. Pediocin (commercially available concentrate ALTA TM 2341 was incorporated at 30, 40 and 50 % w/w. The load at break of films was studied using the Universal Testing Machine (Instron at 10 °C and 25 °C. The water vapor permeability was determined by gravimetric method. A scanning electron microscope was used to study the developed packaging structure. Antimicrobial activity of films against Listeria innoucua and L. monocytogenes was tested both in vitro and in bologna samples. Results showed that values of load at break decreased with increasing concentrations of pediocin at 10 °C and 25 °C. Regarding water vapor permeability, only the control and 50 % pediocin films presented statistical difference, with the 50 % pediocin film being more permeable. In vitro tests showed antimicrobial activity against L. innocua. Cellulosic film with 50 % pediocin reduced L. monocytogenes growth on sliced bologna by 1.2 log cycles after 9 days and prevented biofilm formation on packaging and bologna

  3. Rapid Evaluation of Bacteriolysis of Listeria innocua and L. welshimeri Strains Isolated from Foods

    OpenAIRE

    ÇETİNKAYA, Figen; ÇIBIK, Recep

    2014-01-01

    This study was performed to determine the bacteriolytic extent of 10 strains of Listeria innocua and 9 strains of L. welshimeri isolated from foods. Bacteriolysis was measured at 650 nm by spectrophotometer. For this purpose, late exponential phase cells were transferred into potassium phosphate buffer (100 mM, pH 7.0) and incubated at 37 ºC. While the bacteriolysis range of L. innocua strains was 48% to 76% after 48 h of incubation, L. welshimeri isolates exhibited broader bacteriolytic vari...

  4. Aging and cellular defense mechanisms: age-related changes in resistance of mice to Listeria monocytogenes.

    OpenAIRE

    Patel, P J

    1981-01-01

    Age-related changes in resistance of mice to infection with Listeria monocytogenes were investigated. One-month-old mice exhibited the least resistance, and the resistance level increased over the first few months to reach a maximum by 8 months. Increase in age thereafter was accompanied by a slow but progressive decrease in resistance. Thus, 50% lethal doses for 1-, 8-, and 24-month-old mice were 10(4.2), 10(6.6), and 10(5.2), respectively. In spite of differences in resistance, the growth o...

  5. Microbiological criteria for Listeria monocytogenes in foods under special consideration of risk assessment approaches

    DEFF Research Database (Denmark)

    Nørrung, Birgit

    2000-01-01

    This paper shortly summarizes data related to risk assessment of Listeria monocytogenes. From available data on risk assessment, it is concluded that the levels of L. monocytogenes consumed is an important factor affecting the incidence of listeriosis. Foods that do not support the growth of L....... monocytogenes are unlikely to be a source of listeriosis, whereas foods that support the growth to high levels, should be the target of risk management efforts. Based on current epidemiological information from several countries, a concentration of L. monocytogenes not exceeding 100/g of food at the time...... of L. monocytogenes in the food during prevailing storage and distribution conditions is needed....

  6. The challenge of setting risk-based microbiological criteria for Listeria monocytogenes

    DEFF Research Database (Denmark)

    Andersen, Jens Kirk; Nørrung, Birgit

    2011-01-01

    After more than 20 years of work with discussing the setting of microbiological criteria for Listeria monocytogenes in foods, Codex Alimentarius on Food Hygiene has finalised a proposal that was recently adopted by the Codex Alimentarius Commission. The effort of developing procedures for making...... the microbiological criteria risk-based to the greatest extent possible has challenged scientists and managers during this long time period. Yet, the establishment of microbiological criteria for L. monocytogenes is still being discussed and several approaches are possible. Setting of microbiological criteria...

  7. How the study of Listeria monocytogenes has led to new concepts in biology.

    Science.gov (United States)

    Rolhion, Nathalie; Cossart, Pascale

    2017-06-01

    The opportunistic intracellular bacterial pathogen Listeria monocytogenes has in 30 years emerged as an exceptional bacterial model system in infection biology. Research on this bacterium has provided considerable insight into how pathogenic bacteria adapt to mammalian hosts, invade eukaryotic cells, move intracellularly, interfere with host cell functions and disseminate within tissues. It also contributed to unveil features of normal host cell pathways and unsuspected functions of previously known cellular proteins. This review provides an updated overview of our knowledge on this pathogen. In many examples, findings on L. monocytogenes provided the basis for new concepts in bacterial regulation, cell biology and infection processes.

  8. Specific biological properties of Listeria innocua spp. isolated in Primorye Territory

    Directory of Open Access Journals (Sweden)

    E. A. Zaitseva

    2017-01-01

    Full Text Available Rationale: Most cases of listeriosis are caused by the pathogenic Listeria monocytogenes. Some cases of isolation of L.  innocua with pathogenicity factors from foods have been published, as well as on the cases of the disease in humans caused by this species. Aim: To assess biological properties including potential pathogenicity of L.  innocua, isolated from food and environmental objects. Materials and methods: We performed microbiological study of L. innocua cultures isolated from foods (n = 35 and environmental objects (n = 15 on the territory of Primorye Territory (Russian Federation, as well as assessment of their sensitivity to antibiotics. Results: The studied L.  innocua cultures showed stable phenotypic features of their biological properties, such as morphology, typical colony growth on the medium with characteristic odor of fermented milk, blue or blue-green luminescence induced by inclined light, presence of catalase activity and absence of the oxidase activity. Only 38 ± 6.9% of L.  innocua demonstrated movements at T 22 °С. L.  innocua cultures did not ferment mannitol (100% of cultures; they degraded ramnose to its acid without gas (70 ± 6.5% and degraded xylose (42.8 ± 7%. Listeria isolated from vegetables and environmental objects could ferment ramnose (92.8 ± 7.2% of the studied cultures and xylose (28.5 ± 12.5% more frequently than L. innocua isolated from meat and fish foods. L.  innocua demonstrated variable biochemical activities towards mannose (92 ± 3.8%, saccharose (85.7 ± 7.8% and melesitose (76.2 ± 9.5%. L. innocua cultures with hemolytic activity (34 ± 6.7% (α or β  type were isolated, more commonly from fish products. All Listeria irrespective of their isolation source showed lipase activity. L.  innocua cultures from foods and environmental objects were highly sensitive to antimicrobials from the following classes: penicillins (ampicillin, carbenicillin, combined amoxicillin and clavulanic

  9. Illuminating the landscape of host–pathogen interactions with the bacterium Listeria monocytogenes

    Science.gov (United States)

    Cossart, Pascale

    2011-01-01

    Listeria monocytogenes has, in 25 y, become a model in infection biology. Through the analysis of both its saprophytic life and infectious process, new concepts in microbiology, cell biology, and pathogenesis have been discovered. This review will update our knowledge on this intracellular pathogen and highlight the most recent breakthroughs. Promising areas of investigation such as the increasingly recognized relevance for the infectious process, of RNA-mediated regulations in the bacterium, and the role of bacterially controlled posttranslational and epigenetic modifications in the host will also be discussed. PMID:22114192

  10. Sporadic case of listeriosis associated with the consumption of a Listeria monocytogenes-contaminated 'Camembert' cheese.

    Science.gov (United States)

    Gilot, P; Hermans, C; Yde, M; Gigi, J; Janssens, M; Genicot, A; André, P; Wauters, G

    1997-09-01

    Listeria monocytogenes is an intracellular gram-positive organism responsible for severe infections in both humans and animals. Whereas the food-borne transmission of listeriosis was demonstrated in several outbreaks, most cases of listeriosis occur sporadically and are rarely linked with consumption of contaminated foods. In this paper a case of septicaemia with L. monocytogenes in a 73-year-old immunocompromised man is described. Evidence for the association of this case of listeriosis with the consumption of a contaminated 'Camembert' cheese is provided by serotyping, esterase typing, DNA macrorestriction patterns analysis and level of virulence of the isolated strains for mice.

  11. Survival of Listeria monocytogenes in mozzarella cheese and ice cream exposed to gamma irradiation

    International Nuclear Information System (INIS)

    Hashisaka, A.E.; Weagant, S.D.; Dong, F.M.

    1989-01-01

    The survival of Listeria monocytogenes preinoculated into ice cream and mozzarella cheese prior to gamma-irradiation treatment was determined. Samples were maintained at -78 degrees C and exposed to targeted doses of 2, 4, 8, 16, and 32 kGy of gamma-irradiation. The calculated D10 values were 1.4 kGy for mozzarella cheese and 2.0 kGy for ice cream. The effective level of irradiation (12D) for inactivating L. monocytogenes was 16.8 kGy for mozzarella cheese and 24.4 kGy for ice cream

  12. Peritonitis with Listeria monocytogenes in a patient on automated peritoneal dialysis

    DEFF Research Database (Denmark)

    Poulsen, Hanna Bjarkhamar; Á Steig, Torkil; Björkman, Jonas T

    2018-01-01

    We present a case where Listeria monocytogenesserotype 1/2a was determined to be the causative agent of peritonitis in a patient on automated peritoneal dialysis. The patient, a 53-year-old Caucasian woman from the Faroe Islands was admitted to the National Hospital reporting of constant abdominal...... pain and a fever. Peritoneal cultures were positive for growth of L. monocytogenes. The patient was successfully treated with oral amoxicillin for 2 weeks and intraperitoneal vancomycin for 3 weeks. To date, the patient has not been readmitted due to peritonitis. The Faroese salmon was the suspected...

  13. Modeling the high pressure inactivation kinetics of Listeria monocytogenes on RTE cooked meat products

    DEFF Research Database (Denmark)

    Hereu, A.; Dalgaard, Paw; Garriga, M.

    2012-01-01

    High pressure (HP) inactivation curves of Listeria monocytogenes CTC1034 (ca. 107CFU/g) on sliced RTE cooked meat products (ham and mortadella) were obtained at pressures from 300 to 800MPa. A clear tail shape was observed at pressures above 450MPa and the log-linear with tail primary model...... provided the best fit to the HP-inactivation kinetics. The relationships between the primary kinetic parameters (log kmax and log Nres) and pressure treatments were described by a polynomial secondary model. To estimate HP-inactivation of L. monocytogenes in log (N/N0) over time, a one-step global fitting...

  14. Inactivation of Listeria in Foods Packed in Films Activated with Enterocin AS-48 plus Thymol Singly or in Combination with High-Hydrostatic Pressure Treatment

    Directory of Open Access Journals (Sweden)

    Irene Ortega Blázquez

    2017-11-01

    Full Text Available The aim of the present study was to determine the efficacy of films activated with enterocin AS-48 plus thymol singly, or in combination with high-hydrostatic pressure (HHP on the inactivation of Listeria innocua in sea bream fillets and in fruit puree stored under refrigeration for 10 days. L. innocua proliferated in control fish fillets during storage. The activated film reduced viable Listeria counts in fillets by 1.76 log cycles and prevented growth of survivors until mid-storage. Application of HHP treatment to fillets packed in films without antimicrobials reduced Listeria counts by 1.83 log cycles, but did not prevent the growth of survivors during storage. The combined treatment reduced viable counts by 1.88 log cycles and delayed growth of survivors during the whole storage period. L. innocua survived in puree during storage. The activated film reduced Listeria counts by 1.80 and 2.0 log cycles at days 0 and 3. After that point, Listeria were below the detection limit. No viable Listeria were detected in the purees after application of HHP treatment singly, or in combination with the activated film. Results from the study indicate that the efficacy of activated films against Listeria is markedly influenced by the food type.

  15. Oxygen restriction increases the infective potential of Listeria monocytogenes in vitro in Caco-2 cells and in vivo in guinea pigs

    Directory of Open Access Journals (Sweden)

    Licht Tine

    2007-06-01

    Full Text Available Abstract Background Listeria monocytogenes has been implicated in several food borne outbreaks as well as sporadic cases of disease. Increased understanding of the biology of this organism is important in the prevention of food borne listeriosis. The infectivity of Listeria monocytogenes ScottA, cultivated with and without oxygen restriction, was compared in vitro and in vivo. Fluorescent protein labels were applied to allow certain identification of Listeria cells from untagged bacteria in in vivo samples, and to distinguish between cells grown under different conditions in mixed infection experiments. Results Infection of Caco-2 cells revealed that Listeria cultivated under oxygen-restricted conditions were approximately 100 fold more invasive than similar cultures grown without oxygen restriction. This was observed for exponentially growing bacteria, as well as for stationary-phase cultures. Oral dosage of guinea pigs with Listeria resulted in a significantly higher prevalence (p Listeria in fecal samples was observed after dosage with oxygen-restricted bacteria. These differences were seen after challenge with single Listeria cultures, as well as with a mixture of two cultures grown with and without oxygen restriction. Conclusion Our results show for the first time that the environmental conditions to which L. monocytogenes is exposed prior to ingestion are decisive for its in vivo infective potential in the gastrointestinal tract after passage of the gastric barrier. This is highly relevant for safety assessment of this organism in food.

  16. Listeria monocytogenes en manipuladores de alimentos: un nuevo enfoque para tener en cuenta en los peligros de la industria alimentaria

    Directory of Open Access Journals (Sweden)

    Ángela Bibiana Muñoz

    2013-06-01

    Full Text Available Introducción. Las enfermedades transmitidas por alimentos constituyen un problema sanitario dealto impacto. Listeria monocytogenes se asocia frecuentemente con contaminación de alimentos lácteos y cárnicos. Vigilar su presencia en varios puntos de esta producción, es vital para controlar la diseminación del microorganismo. Objetivo. Determinar la prevalencia de L. monocytogenes en manipuladores de alimentos de lácteos y cárnicos en 10 departamentos de Colombia y buscar la asociación entre la presencia del microorganismo y posibles factores de riesgo. Materiales y métodos. Se llevó a cabo un estudio descriptivo de corte transversal, en el cual se determinó la presencia de L. monocytogenes en muestras de materia fecal y frotis de manos, provenientes de 1.322 manipuladores de alimentos. Se aplicó un cuestionario para conocer posibles factores de riesgo, y se llevó a cabo un análisis estadístico para determinar frecuencias y establecer relaciones entre los posibles factores de riesgo y el estado del portador. Resultados. Hubo 138 (10,4 % manipuladores de alimentos que resultaron positivos para L. monocytogenes y se encontró asociación estadísticamente significativa entre la presencia del microorganismo y “no conocer el concepto de contaminación cruzada” (OR (IC95%=1,518; p=0,004, así como con “no practicar procedimientos de limpieza y desinfección adecuados” (OR (IC95%=1,292;p=0,005. Conclusión. Se estableció una prevalencia de portadores de L. monocytogenes entre manipuladoresde alimentos de derivados lácteos y cárnicos, y se logró asociar las prácticas higiénicas de los manipuladores de alimentos como factores de riesgo. El estudio se convierte en una herramienta útil para la vigilancia, la caracterización epidemiológica y el planteamiento de estrategias de control de este microorganismo.   doi: http://dx.doi.org/10.7705/biomedica.v33i2.716

  17. Establishment of a simple and rapid identification method for Listeria spp. by using high-resolution melting analysis, and its application in food industry.

    Science.gov (United States)

    Ohshima, Chihiro; Takahashi, Hajime; Phraephaisarn, Chirapiphat; Vesaratchavest, Mongkol; Keeratipibul, Suwimon; Kuda, Takashi; Kimura, Bon

    2014-01-01

    Listeria monocytogenes is the causative bacteria of listeriosis, which has a higher mortality rate than that of other causes of food poisoning. Listeria spp., of which L. monocytogenes is a member, have been isolated from food and manufacturing environments. Several methods have been published for identifying Listeria spp.; however, many of the methods cannot identify newly categorized Listeria spp. Additionally, they are often not suitable for the food industry, owing to their complexity, cost, or time consumption. Recently, high-resolution melting analysis (HRMA), which exploits DNA-sequence differences, has received attention as a simple and quick genomic typing method. In the present study, a new method for the simple, rapid, and low-cost identification of Listeria spp. has been presented using the genes rarA and ldh as targets for HRMA. DNA sequences of 9 Listeria species were first compared, and polymorphisms were identified for each species for primer design. Species specificity of each HRM curve pattern was estimated using type strains of all the species. Among the 9 species, 7 were identified by HRMA using rarA gene, including 3 new species. The remaining 2 species were identified by HRMA of ldh gene. The newly developed HRMA method was then used to assess Listeria isolates from the food industry, and the method efficiency was compared to that of identification by 16S rDNA sequence analysis. The 2 methods were in coherence for 92.6% of the samples, demonstrating the high accuracy of HRMA. The time required for identifying Listeria spp. was substantially low, and the process was considerably simplified, providing a useful and precise method for processing multiple samples per day. Our newly developed method for identifying Listeria spp. is highly valuable; its use is not limited to the food industry, and it can be used for the isolates from the natural environment.

  18. Esporotricosis diagnosticada por el laboratorio

    Directory of Open Access Journals (Sweden)

    Nelly Ordóñez

    1989-06-01

    Full Text Available De 1976 a 1989 se han diagnosticado 40 casos de esporotricosis en el laboratorio de Micología del Instituto Nacional de Salud. La enfermedad se presentó en pacientes entre 4 y 52 años y tuvo predilección por el sexo masculino: 35 de 40 (87,5%; las formas clínicas más frecuentes fueron la cutánea fija, 18 de 40 (45%, y la linfocutánea, 17 de 40 (42,5%, con localización mayor en miembros superiores, 18 de 40 (45%. El diagnóstico se estableció por el aislamiento del Sporothrix schenckii en 35 de 38 pacientes (92%; los otros dos pacientes se diagnosticaron empleando otras técnicas: inmunofluorescencia directa, intradermorreacción y aglutinación en tubo.

  19. Miasis cutanea por cordylobia anthropophaga

    Directory of Open Access Journals (Sweden)

    Alkorta Gurrutxaga Miriam

    2001-01-01

    Full Text Available El incremento progresivo en el número de personas que viajan a países tropicales ha hecho que las enfermedades importadas adquieran una relevancia cada vez mayor. Las miasis (o infestaciones por larvas de moscas cutáneas se encuentran entre este tipo de enfermedades siendo especialmente frecuentes en países tropicales. A propósito de la observación de un caso de miasis cutánea masiva por Cordylobia antropophaga, que ocurrió en una mujer de 34 años de edad al volver de un viaje a Senegal, se ha efectuado una revisión de los casos de miasis cutáneas forunculoides importadas publicados en España, así como de la biología, patología, tratamiento y prevención de la miasis humana por Cordylobia anthropophaga. El caso referido, se caracterizó por la infestación con un número inusualmente elevado de larvas, no sospechándose su etiología hasta la fase final de la enfermedad. La emergencia continuada de larvas (se recogieron 91 generó en la paciente un estado de ansiedad importante. Finalmente, la eliminación de las larvas provocó una rápida mejoría de la paciente. Aunque los casos de miasis cutánea no tienen la gravedad de otras enfermedades importadas, su conocimiento es necesario desde el punto de vista preventivo, diagnóstico y terapeútico. Es importante proceder a la identificación morfológica de las larvas diferenciándolas de otro tipo de miasis con implicaciones terapéuticas diferentes.

  20. Determinaci?n de Listeria monocytogenes en quesos blancos artesanales expendidos en la plaza de mercado de C?queza, Cundinamarca

    OpenAIRE

    Baquero Acu?a, Deissy Milena; Bernal Gonz?lez, Astrid Marcela; Campuzano, Silvia

    2006-01-01

    Las intoxicaciones alimentar?as son un problema de salud p?blica, ya que estas se presentan en cualquier tipo de poblaci?n aumentando la prevalencia en personas inmunosuprimidas, mujeres embarazadas y personas de edad avanzada. Seg?n los datos obtenidos, el 80% de las muestras positivas para Listeria spp presentaron Listeria monocytogenes y el 20% Listeria innocua, indicando una prevalencia de la especie pat?gena para los humanos, aumentando el riesgo en la poblaci?n de padecer enfermedades g...

  1. LISTERIA SPP., COLIFORMES TOTAIS E FECAIS E E.COLI NO LEITE CRU E PASTEURIZADO DE UMA INDÚSTRIA DE LATICÍNIOS, NO ESTADO DA PARAÍBA (BRASIL

    Directory of Open Access Journals (Sweden)

    CATÃO Raïssa Mayer Ramalho

    2001-01-01

    Full Text Available Investigou-se a qualidade microbiológica do leite in natura e na linha de produção (leite recém-pasteurizado e leite ensacado, de uma usina de beneficiamento em Campina Grande-PB. Foi pesquisada a presença de Listeria spp. e sua diversidade de espécies, os níveis de coliformes totais (CT, coliformes fecais (CF e Escherichia coli. Analisou-se um total de 75 amostras de leite, sendo 45 de leite cru, 15 de leite recém-pasteurizado e 15 de leite ensacado. Os resultados foram reunidos em dois grupos segundo o período de monitoramento: antes e após mudanças no processo de higienização da usina. Foi evidenciada elevada contaminação nas amostras de leite cru nas duas épocas. Na primeira (março-abril/1998, todas as amostras de leite beneficiado estiveram fora dos padrões da legislação vigente para CT e CF; na segunda (maio-agosto/1998, houve acentuada redução dos níveis destas bactérias indicadoras, porém as melhorias na higienização não foram suficientes para solucionar este problema, visto que 11,1% das amostras recém-pasteurizadas estavam fora dos padrões para CT e 33,3% para CF. Das amostras ensacadas, 22,2% estavam fora dos padrões para CT e 44,4% para CF. Comparando-se os resultados de CT, CF, e E.coli nas amostras de leite recém-pasteurizado e não ensacado com as amostras de leite ensacado, foi verificado que as amostras após serem pasteurizadas e ensacadas apresentaram valores de CT e CF levemente mais elevados, sugerindo contaminação durante o processo de ensacamento ou falhas na armazenagem. Observou-se que 33 (73,3% das amostras de leite cru e 9 (30% das de leite pasteurizado estavam contaminadas com Listeria spp., sendo identificadas L. monocytogenes em 17 (51,5% amostras de leite cru e em 9 (100% de leite beneficiado (4 recém-pasteurizadas e 5 ensacadas. Em relação à diversidade de espécies, nas amostras de leite cru foram encontradas: L. monocytogenes (66,6%, L. innocua (25,3%, L. ivanovii (3,9%, L

  2. Effect of benzalkonium chloride on viability and energy metabolism in exponential- and stationary-growth-phase cells of Listeria monocytogenes

    NARCIS (Netherlands)

    Luppens, S.B.I.; Abee, T.; Oosterom, J.

    2001-01-01

    The difference in killing exponential- and stationary-phase cells of Listeria monocytogenes by benzalkonium chloride (BAC) was investigated by plate counting and linked to relevant bioenergetic parameters. At a low concentration of BAC (8 mg liter-1), a similar reduction in viable cell numbers was

  3. Enhanced levels of cold shock proteins in Listeria monocytogenes LO28 upon exposure to low temperature and high hydrostatic pressure

    NARCIS (Netherlands)

    Wemekamp-Kamphuis, H.H.; Karatzas, A.K.; Wouters, J.A.; Abee, T.

    2002-01-01

    Listeria monocytogenes is a psychrotrophic food-borne pathogen that is problematic for the food industry because of its ubiquitous distribution in nature and its ability to grow at low temperatures and in the presence of high salt concentrations. Here we demonstrate that the process of adaptation to

  4. Diverse genomic location and sequence content of a Listeria monocytogenes chromosomal island harboring heavy metal resistance and other genes

    Science.gov (United States)

    Listeria monocytogenes remains a major foodborne pathogen with three serotype 4b clonal groups (ECI, ECII, ECIa) repeatedly implicated in human listeriosis. For reasons that are unknown, many of these strains are also resistant to heavy metals, i.e. cadmium and arsenic. The acquisition and fitness i...

  5. Elimination of Listeria inoculated in ready-to-eat carrots by combination of antimicrobial coating and γ-irradiation

    International Nuclear Information System (INIS)

    Turgis, Mélanie; Millette, Mathieu; Salmieri, Stéphane; Lacroix, Monique

    2012-01-01

    A combined treatment of an edible coating composed of trans-cinnamaldehyde (TCN; 0.5% p/p) with γ-irradiation was investigated against Listeria inoculated in peeled mini-carrots. First, the D 10 value (γ-irradiation dose required to eliminate 90% of the bacterial population) of TCN was evaluated under air. This treatment resulted in a 3.66-fold increase in relative bacterial radiosensitivity (RBR) as compared to the control without antimicrobial coating. Secondly, the shelf life of mini-carrots during 21 day of storage at 4 °C was studied. Antimicrobial coating containing TCN was assayed in combination with two irradiation doses (0.25 and 0.5 kGy). Results suggested that the inactive coating did not have any antimicrobial effect against Listeria while the coating containing TCN resulted in a 1.29 log reduction in carrots packed under air after 21 days of storage. Hence, these observations indicated that the combination of irradiation with antimicrobial coating played an important role in enhancing the radiosensitization of Listeria to γ-irradiation. - Highlights: ► Synergistic effect of essential oils and γ-radiation against food pathogens. ► Reducing any undesirable organoleptic impact due to high concentration of EOs. ► Potential in controlling food pathogens and food spoilage bacteria in food. ► Elimination of Listeria monocytogenes in the carrots during the storage.

  6. Detection of Listeria monocytogenes in ready-to-eat foods sampled from a catering service in Apulia, Italy.

    Science.gov (United States)

    Caggiano, Giuseppina; De Giglio, Osvalda; Lovero, Grazia; Rutigliano, Serafina; Diella, Giusy; Balbino, Stella; Napoli, Christian; Montagna, Maria Teresa

    2015-01-01

    Listeria monocytogenes is currently considered a relevant emerging food-borne pathogen. In particular, the European Centre for Disease Prevention and Control (ECDC) illustrates its widespread presence in different foods. In the present article, L. monocytogenes prevalence was estimated in cooked ready-to-eat foods sampled from a catering service in a Apulia city, southern Italy. The study was carried out from January to June 2014 in according to Regulation (EC) No. 852/2004, and ISO 11290-1:1996/Amd.1:2004 methods. Listeria spp. was isolated in 8.3% of the samples: L. monocytogenes was identified with the highest prevalence in potato gateau (66.6%), followed by rice dishes (11.1%), Listeria innocua was isolated from potato purea (11.1%) and cooked vegetables (11.1%). These preliminary results confirm the diffusion of the microorganism in ready-to-eat products; therefore, strategies aimed at protecting the consumers should be adopted. First of all, correct hygiene procedures should be followed and then microbiological tests should be implemented in order to early detect Listeria spp. (not only LM) contamination in cooked foods.

  7. Physical sample structure as predictive factor in growth modeling of Listeria innocua in a white cheese model system

    DEFF Research Database (Denmark)

    Møller, Sandie M.; Bertram, Hanne C.; Andersen, Ulf

    2013-01-01

    Growth of Listeria innocua at 9 °C was investigated in white cheeses manufactured from ultra-filtrate milk concentrate added varying amounts of skimmed milk powder, NaCl and glucono-delta-lactone. Characterization of the white cheese structures was performed using nuclear magnetic resonance (NMR) T...

  8. The role of Listeria monocytogenes cell wall surface anchor protein LapB in virulence, adherence, and intracellular replication

    Science.gov (United States)

    Lmof2365_2117 is a Listeria monocytogenes putative cell wall surface anchor protein with a conserved domain found in collagen binding proteins. We constructed a deletion mutation in lmof2365_2117 in serotype 4b strain F2365, evaluated its virulence, and determined its ability to adhere and invade co...

  9. Modeling Bacteriocin Resistance and Inactivation of Listeria innocua LMG 13568 by Lactobacillus sakei CTC 494 under Sausage Fermentation Conditions

    Science.gov (United States)

    Leroy, Frédéric; Lievens, Kristoff; De Vuyst, Luc

    2005-01-01

    In mixed cultures, bacteriocin production by the sausage isolate Lactobacillus sakei CTC 494 rapidly inactivated sensitive Listeria innocua LMG 13568 cells, even at low bacteriocin activity levels. A small fraction of the listerial population was bacteriocin resistant. However, sausage fermentation conditions inhibited regrowth of resistant cells. PMID:16269805

  10. Transmission electron microscopy study of Listeria monocytogenes serotype 1/2a cells exposed to sublethal heat stress and carvacrol

    Science.gov (United States)

    The objective of this study was to investigate the morphological changes that occurred in Listeria monocytogenes serotype 1/2a cells as visualized by transmission electron microscopy (TEM) after exposure to sublethal heat stress at 48°C for 60 min and in combination with lethal concentration of carv...

  11. Directed evolution and targeted mutagenesis to murinize Listeria monocytogenes internalin A for enhanced infectivity in the murine oral infection model.

    LENUS (Irish Health Repository)

    Monk, Ian R

    2010-01-01

    Internalin A (InlA) is a critical virulence factor which mediates the initiation of Listeria monocytogenes infection by the oral route in permissive hosts. The interaction of InlA with the host cell ligand E-cadherin efficiently stimulates L. monocytogenes entry into human enterocytes, but has only a limited interaction with murine cells.

  12. Development of a nucleic acid lateral flow immunoassay for simultaneous detection of Listeria spp. and Listeriamonocytogenes in food

    NARCIS (Netherlands)

    Blazkova, M.; Koets, M.; Rauch, P.; Amerongen, van A.

    2009-01-01

    We present a new nucleic acid lateral flow immunoassay (NALFIA) for the assessment of listeria contamination. The detection procedure starts with enrichment of sample in Half Fraser broth (24 h). Following isolation of DNA, a duplex PCR is performed with two labelled primer sets, one generic and

  13. Modelling and predicting the simultaneous growth of Listeria monocytogenes and spoilage micro-organisms in cold-smoked salmon

    DEFF Research Database (Denmark)

    Gimenez, B.; Dalgaard, Paw

    2004-01-01

    Aims: To evaluate and model the simultaneous growth of Listeria monocytogenes and spoilage micro-organisms in cold-smoked salmon.Methods and Results: Growth kinetics of L. monocytogenes, lactic acid bacteria (LAB), Enterobacteriaceae, enterococci and Photobacterium phosphoreum were determined...

  14. THE BACTERICIDAL ACTIVITY OF NORMAL GUINEA PIG SERUM AGAINST LISTERIA MONOCYTOGENES AND ITS INHIBITION BY A LISTERIAL CELL EXTRACT,

    Science.gov (United States)

    Normal guinea pig serum contains bactericidins active against Listeria monocytogenes. The listeriocidal activity of the serum did not increase after...factor. Lysozyme was not implicated in the bactericidal system. It was suggested that the bactericidal activity of guinea pig serum might be due either to

  15. Crystal Structure of the Substrate-Binding Domain from Listeria monocytogenes Bile-Resistance Determinant BilE

    NARCIS (Netherlands)

    Ruiz, Stephanie J.; Schuurman-Wolters, Gea K.; Poolman, Bert

    2016-01-01

    BilE has been reported as a bile resistance determinant that plays an important role in colonization of the gastrointestinal tract by Listeria monocytogenes, the causative agent of listeriosis. The mechanism(s) by which BilE mediates bile resistance are unknown. BilE shares significant sequence

  16. Determining If Phylogenetic Relatedness of Listeria Monocytogenes Isolates Corresponds to Persistence in Poultry Processing Plants Using Whole-Genome Sequencing

    Science.gov (United States)

    Introduction: Controlling Listeria monocytogenes on ready-to-eat meat and poultry products and in food processing facilities is challenging. Surveys have found that some L. monocytogenes types are more persistent in processing facilities than others, but the reason is unknown. It is possible persist...

  17. Listeria monocytogenes source distribution analysis indicates regional heterogeneity and ecological niche preference among serotype 4b clones

    Science.gov (United States)

    Human illness due to the foodborne bacterial pathogen Listeria monocytogenes frequently involves certain widely disseminated clonal complexes (CCs), primarily of serotype 4b. CC1, CC2 and CC6, previously also designated epidemic clone (EC) I, Ia and II, respectively, have been frequently implicate...

  18. Listeria monocytogenes persistence and transfer to cantaloupes in the packing environment is affected by equipment surface type and cleanliness

    Science.gov (United States)

    Cantaloupes have frequently been contaminated with bacterial pathogens and caused several high profile outbreaks over the years. In 2011, Rocky Ford cantaloupes contaminated with Listeria monocytogenes sickened 147 people and resulted in 33 fatalities, making it the deadliest foodborne outbreak in t...

  19. Self-contained chlorine dioxide generation and delivery pods for controlling Listeria monocytogenes in model floor drains.

    Science.gov (United States)

    Listeria monocytogenes is a foodborne pathogen that has been associated with poultry products. This organism is ubiquitous in nature and has been found to enter poultry further processing plants on incoming raw product. Once in the plant, L. monocytogenes can become a long term persistent colonize...

  20. Spatial and Temporal Factors Associated with an Increased Prevalence of Listeria monocytogenes in Spinach Fields in New York State

    Science.gov (United States)

    Weller, Daniel; Wiedmann, Martin

    2015-01-01

    While rain and irrigation events have been associated with an increased prevalence of foodborne pathogens in produce production environments, quantitative data are needed to determine the effects of various spatial and temporal factors on the risk of produce contamination following these events. This study was performed to quantify these effects and to determine the impact of rain and irrigation events on the detection frequency and diversity of Listeria species (including L. monocytogenes) and L. monocytogenes in produce fields. Two spinach fields, with high and low predicted risks of L. monocytogenes isolation, were sampled 24, 48, 72, and 144 to 192 h following irrigation and rain events. Predicted risk was a function of the field's proximity to water and roads. Factors were evaluated for their association with Listeria species and L. monocytogenes isolation by using generalized linear mixed models (GLMMs). In total, 1,492 (1,092 soil, 334 leaf, 14 fecal, and 52 water) samples were collected. According to the GLMM, the likelihood of Listeria species and L. monocytogenes isolation from soil samples was highest during the 24 h immediately following an event (odds ratios [ORs] of 7.7 and 25, respectively). Additionally, Listeria species and L. monocytogenes isolates associated with irrigation events showed significantly lower sigB allele type diversity than did isolates associated with precipitation events (P = monocytogenes contamination. Small changes in management practices (e.g., not irrigating fields before harvest) may therefore reduce the risk of L. monocytogenes contamination of fresh produce. PMID:26116668

  1. Mixed species biofilms of Listeria monocytogenes and Lactobacillus plantarum show enhanced resistance to benzalkonium chloride and peracetic acid

    NARCIS (Netherlands)

    Veen, van der S.; Abee, T.

    2011-01-01

    We investigated the formation of single and mixed species biofilms of Listeria monocytogenes strains EGD-e and LR-991, with Lactobacillus plantarum WCFS1 as secondary species, and their resistance to the disinfectants benzalkonium chloride and peracetic acid. Modulation of growth, biofilm formation,

  2. Importance of SigB for Listeria monocytogenes static and continuous flow biofilm formation and disinfectant resistance

    NARCIS (Netherlands)

    Veen, van der S.; Abee, T.

    2010-01-01

    Listeria monocytogenes is a food-borne pathogen that is able to form biofilms in food processing facilities. Biofilms are generally more resistant to antimicrobial agents, making it difficult to eradicate them during cleanup procedures. So far, little is known about the function of stress resistance

  3. In vitro and in vivo invasiveness of different pulsed-field get electrophoresis types of Listeria monocytogenes

    DEFF Research Database (Denmark)

    Larsen, Charlotte Nexmann; Nørrung, Birgit; Sommer, Helle Mølgaard

    2002-01-01

    The virulence of different pulsed-field gel electrophoresis (PFGE) types of Listeria monocytogenes was examined by monitoring their ability to invade Caco-2 cells. Strains belonging to seven different PFGE types originating from both foods and humans were included. No significant differences...

  4. Inactivation of Salmonella enterica and Listeria monocytogenes in cantaloupe puree by high hydrostatic pressure with/without added ascorbic acid

    Science.gov (United States)

    The objective of this research was to evaluate and develop a method for inactivation of Salmonella enterica and Listeria monocytogenes in cantaloupe puree (CP) by high hydrostatic pressure (HHP). Cantaloupe being the most netted varieties of melons presents a greater risk of pathogen transmission. ...

  5. Inhibition of Listeria monocytogenes by pomegranate (Punica granatum) peel extract in meat paté at different temperatures

    NARCIS (Netherlands)

    Hayrapetyan, H.; Hazeleger, W.C.; Beumer, R.R.

    2012-01-01

    Natural antimicrobials are being more and more considered as alternative approach for controlling growth of microorganisms in food. The objective of this study was to evaluate the pomegranate extract’s (PE) potential to be used as a natural preservative in ready to eat meats. Listeria monocytogenes

  6. Genes that are involved in high hydrostatic pressure treatments in a Listeria monocytogenes Scott A ctsR deletion mutant

    Science.gov (United States)

    Listeria monocytogenes is a food-borne pathogen of significant threat to public health. High Hydrostatic Pressure (HHP) treatment can be used to control L. monocytogenes in food. The CtsR (class three stress gene repressor) protein negatively regulates the expression of class III heat shock genes....

  7. An outbreak of febrile gastroenteritis associated with corn contaminated by Listeria monocytogenes.

    Science.gov (United States)

    Aureli, P; Fiorucci, G C; Caroli, D; Marchiaro, G; Novara, O; Leone, L; Salmaso, S

    2000-04-27

    On May 21, 1997, numerous cases of febrile gastrointestinal illness were reported among the students and staff of two primary schools in northern Italy, all of whom had eaten at cafeterias served by the same caterer. We interviewed people who ate at the cafeterias about symptoms and foods consumed on May 20. There were no samples of foods left at the cafeterias, but we tested routine samples taken on May 20 by the caterer and environmental specimens at the catering plant. The hospitalized patients were tested for common enteropathogens and toxins. Of the 2189 persons interviewed (82 percent of those exposed), 1566 (72 percent) reported symptoms; of these, 292 (19 percent) were hospitalized. Among samples obtained from hospitalized patients, all but two of the stool specimens and all blood specimens were negative for common enteropathogens. Listeria monocytogenes was isolated from one blood specimen and from 123 of the 141 stool specimens. Consumption of a cold salad of corn and tuna was associated with the development of symptoms (relative risk, 6.19; 95 percent confidence interval, 4.81 to 7.98; Pcaterer's sample of the salad and from environmental specimens collected from the catering plant. All listeria isolates were serotype 4b and were found to be identical on DNA analysis. Experimental contamination of sterile samples of the implicated foods showed that L. monocytogenes grew on corn when kept for at least 10 hours at 25 degrees C. Food-borne infection with L. monocytogenes can cause febrile illness with gastroenteritis in immunocompetent persons.

  8. The preservation of Listeria-critical foods by a combination of endolysin and high hydrostatic pressure.

    Science.gov (United States)

    Misiou, Ourania; van Nassau, Tomas J; Lenz, Christian A; Vogel, Rudi F

    2018-02-02

    The aim of this work was to examine the combination of endolysin PlyP825 and high hydrostatic pressure (HHP) processing against a cocktail of stationary phase Listeria monocytogenes cells in several Listeria-critical food products (i.e. milk, mozzarella and smoked salmon). In order to determine the efficacy of the combined application, both challenge-lethality tests and storage tests were performed. In milk and mozzarella, we could demonstrate that the application of PlyP825 prior to HHP processing allowed for a synergistic inactivation of cells, a reduction in the pressure level with equal antimicrobial efficacy and an enhanced eradication of L. monocytogenes during storage at abuse temperatures. For smoked salmon, no such effects were detected. Although the efficacy of the method was highly dependent on the food vehicle and parameters applied, we hereby demonstrated the potential of the combined endolysin-HHP application for complete eradication of L. monocytogenes from foods at milder processing conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Listeria monocytogenes associated kerato-conjunctivitis in four horses in Norway.

    Science.gov (United States)

    Revold, Tobias; Abayneh, Takele; Brun-Hansen, Hege; Kleppe, Signe L; Ropstad, Ernst-Otto; Hellings, Robert A; Sørum, Henning

    2015-11-09

    Listeria monocytogenes has been reported to cause various infectious diseases in both humans and animals. More rarely, ocular infections have been reported. To our knowledge, only two cases of Listeria keratitis have been described in horses. We report kerato-conjunctivitis in four Norwegian horses associated with L. monocytogenes. Clinically, all cases were presented with recurrent unilateral kerato-conjunctivitis. L. monocytogenes bacteria were isolated from swab samples from all cases, and cytology carried out in 3 cases was indicative of L. monocytogenes infection. The present report describes the first known cases in which L. monocytogenes has been isolated from keratitic lesions in horses in Norway. A potential risk factor may be feeding of silage or haylage, but other sources of infection cannot be ruled out. The phenotypic features including antimicrobial susceptibility and serotype of the isolates are described. Laboratory detection of L. monocytogenes demands extra caution since only low numbers of bacteria were detected in the eye-swabs, probably due to the low volume of sample material and the intracellular niche of the bacterium. A general poor response to treatment in all these cases indicates that clinicians should pay extra attention to intensity and duration of treatment if L. monocytogenes is identified in connection with equine kerato-conjunctivitis.

  10. Cloning and Expression of Listeria monocytogenes Listeriolysin O in Lactobacillus plantarum

    Directory of Open Access Journals (Sweden)

    Masoumeh Hayati

    2017-11-01

    Full Text Available Background: The protein listeriolysin O (LLO encoded by hly gene, is one of the most important virulence factors of Listeria monocytogenes. This highly potent immunogenic cholesterol binding toxin has hemolytic activity, responsible for phagosomal membrane disruption and bacterial escape to the cytoplasm and facilitating the stimulation of CD8+ T cells and Th1 response. Recently pathobiotechnological vaccination using probiotic bacteria have been proposed. One of these strategies is expression of LLO in non-pathogenic bacteria such as lactic acid bacteria as delivery strains. Objectives: Our aim in this study was cloning of hly gene in a Lactobacillus species via pNZ8110, an inducible expression vector which is specific for Lactococcus species. Materials and Methods: hly gene was amplified by PCR and cloned into pNZ8110 by restriction enzymes cutting and ligation method. After transformation and propagation in E. coli MC1061 intermediate host, it was successfully electrotransformed into Lactobacillus plantarum. Results: Gel electrophoresis of colony PCR, extracted plasmids and restriction analysis along with sequencing confirmed the transformation. After induction using supernatant of nisin producer Lactococcus lactis NZ9700 strain, Expression of LLO was confirmed by SDS PAGE and western blot. Conclusion: Here, we have employed a nonpathogenic probiotic strain; Lactobacillus plantarum for the first time to express hly gene of Listeria monocytogenes in order to propose a new vaccine candidate.

  11. Evaluation of anti-Listeria meat borne Lactobacillus for biofilm formation on selected abiotic surfaces.

    Science.gov (United States)

    Pérez Ibarreche, Mariana; Castellano, Patricia; Vignolo, Graciela

    2014-01-01

    The ability of meat borne anti-Listeria Lactobacillus to form biofilms under different in vitro conditions and on abiotic surfaces was investigated. Biofilm formation by the adhesion to polystyrene microtiter plates was determined, this being higher for Lactobacillus curvatus CRL1532 and CRL705 and Lactobacillus sakei CRL1862. The physicochemical properties of the cell surface were relatively hydrophilic and acidic in character; L. sakei CRL1862 exhibiting the strongest autoaggregation. The adhesion of lactobacilli to stainless steel (SS) and polytetrafluoroethylene (PTFE) supports at 10°C was found to be maximal for L. sakei CRL1862 on SS after 6 days. When biofilm architecture was characterized by epifluorescence and SEM, L. sakei CRL1862 homogeneously covered the SS surface while cell clusters were observed on PTFE; the extracellular polymeric substance matrix adapted to the topography and hydrophilic/hydrophobic characteristics of each material. The feasibility of L. sakei CRL1862 to form biofilm on materials used in meat processing highlights its potential as a control strategy for Listeria monocytogenes biofilms. © 2013. Published by Elsevier Ltd. All rights reserved.

  12. Characterization of cellular fatty acids of listeria species and their effect on circulating blood monocytes

    International Nuclear Information System (INIS)

    Omm-e-Hany; Khan, M.A.; Khan, M.A.; Shahzad, A.; Ahmed, W.; Siddiqi, R.; Atta-ur-Rehman

    2011-01-01

    Listeria monocytogenes NCTC 7973, L. ivanovii SLCC 2379 and L. seeligeri SLCC 3954 were found to contain 5 - 7.8 % (dry weight) chloroform- soluble lipids. All species exhibited, nearly similar fatty acid esters profile with little difference when grown at 37 deg. C. The study revealed the abundance of odd chain saturated fatty acids in all the three species of Listeria. Among all, in particular ante-iso are more prevalent than iso- forms. The high percentage of the C15 fatty acid ester was characteristic of each species but with some differences in the relative amounts were observed. C19 and C22 fatty acid esters were characteristic of L. monocytogenes. Whole cells of L. monocytogenes and L. ivanovii induced strong monocytosis in the infected animals (rabbits, mice, and rats) of varying degree of susceptibility. Similar effect was observed with crude lipid extract of L.moncytogenes. No such response was observed even when live L. seeligri cells or crude lipid of L. ivanovii were injected. (author)

  13. Prevalence and populations of Listeria monocytogenes in meat products retailed in Sao Paulo, Brazil.

    Science.gov (United States)

    Ristori, Christiane Asturiano; Rowlands, Ruth Estela Gravato; Martins, Cecília Geraldes; Barbosa, Maria Luisa; Yoshida, Júlia T U; Franco, Bernadette D G de Melo

    2014-12-01

    This study evaluated the prevalence of the populations and serotypes of Listeria monocytogenes in 552 refrigerated samples of ground beef, chicken leg, hot dog, and pork sausage collected in supermarkets in the city of Sao Paulo, SP, Brazil, between May 2008 and July 2009. The supermarkets were selected after stratification by geographical region and by random draw. Tests for presence and enumeration of L. monocytogenes were based on ISO 11290-1:1996/Amd.1:2004 and ISO 11290-2:1998 methods, respectively. Listeria spp. were detected in 469 (85.0%) of the studied meat products. The most frequently isolated species was L. innocua (64.1%), followed by L. monocytogenes (48.7%), L. welshimeri (13.4%), L. seeligeri (7.1%), L. ivanovii (0.2%), and L. grayi subspecies murrayi (0.2%). L. monocytogenes was detected in 269 (48.7%) samples, with highest prevalence in ground beef (59.4%) followed by chicken legs (58.0%), pork sausages (39.8%), and hot dogs (37.7%). The populations were Prevalence of serotypes varied according to the type of meat product. These data are relevant for estimating the risks of listeriosis associated with consumption of meat products in Sao Paulo, and for establishing science-based intervention strategies aimed at reducing these risks, especially for pregnant women and immunocompromised individuals.

  14. The high prevalence of Listeria monocytogenes peritonitis in cirrhotic patients of an Egyptian Medical Center.

    Science.gov (United States)

    El Sayed Zaki, Maysaa; El Shabrawy, Walaa Othman; El-Eshmawy, Mervat M; Aly Eletreby, Shahera

    2011-09-01

    Spontaneous bacterial peritonitis (SBP) is a potentially lethal complication of cirrhosis. It is probably the most characteristic infectious complication of cirrhosis. The aim of this study was to evaluate the bacterial and fungal causes of SBP in Egyptian population. Furthermore to predict the occurrence of rare pathogen like Listeria monocytogenes in those patients. The study included 100 patients with end stage liver disease associated with ascites. Patients were suspected to have SBP. The ascitic fluids were subjected to full cytological and microbiological study. The peritoneal fluid cytological study revealed that 50 samples had cell counts >250 cells/mm(3). 37 samples had growth and 13 samples had no growth (CNNA). The distribution of isolated pathogens was Gram positive cocci 48.8% followed by L. monocytogenes 24.4%, Gram negative bacilli 12.2% and Mycobacterium tuberculosis 7.3. The cells counts associated with listeria culture were 475 cells/mm(3) with sensitivity 70% and specificity 68%. The study highlights the prevalence of microorganisms in Egyptian patients with liver cirrhosis associated with ascites. It reflects the occurrence of L. monocytogenes as an important pathogen of such clinical situation. Other rare pathogens like M. tuberculosis are not uncommon in those patients. Copyright © 2011 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

  15. 28-mer Fragment Derived from Enterocin CRL35 Displays an Unexpected Bactericidal Effect on Listeria Cells.

    Science.gov (United States)

    Masias, Emilse; Sanches, Paulo R S; Dupuy, Fernando G; Acuna, Leonardo; Bellomio, Augusto; Cilli, Eduardo; Saavedra, Lucila; Minahk, Carlos

    2015-01-01

    Two shorter peptides derived from enterocin CRL35, a 43-mer bacteriocin, were synthesized i.e. the N-terminal fragment spanning from residues 1 to 15, and a 28-mer fragment that represents the C-terminal of enterocin CRL35, the residues 16 to 43. The separate peptides showed no activity when combined. On one hand, the 28-mer peptide displayed an unpredicted antimicrobial activity. On the other, 15- mer peptide had no consistent anti-Listeria effect. The dissociation constants calculated from experimental data indicated that all peptides could bind at similar extent to the sensitive cells. However, transmembrane electrical potential was not dissipated to the same level by the different peptides; whereas the full-length and the C-terminal 28-mer fragment induced almost full dissipation, 15-mer fragment produced only a slow and incomplete effect. Furthermore, a different interaction of each peptide with membranes was demonstrated based on studies carried out with liposomes, which led us to conclude that activity was related to structure rather than to net positive charges. These results open up the possibility of designing new peptides based on the 28-mer fragment with enhanced activity, which would represent a promising approach for combating Listeria and other pathogens.

  16. Attachment of Salmonella serovars and Listeria monocytogenes to stainless steel and plastic conveyor belts.

    Science.gov (United States)

    Veluz, G A; Pitchiah, S; Alvarado, C Z

    2012-08-01

    In poultry industry, cross-contamination due to processing equipment and contact surfaces is very common. This study examined the extent of bacterial attachment to 6 different types and design of conveyor belts: stainless steel-single loop, stainless steel-balance weave, polyurethane with mono-polyester fabric, acetal, polypropylene mesh top, and polypropylene. Clean conveyor belts were immersed separately in either a cocktail of Salmonella serovars (Salmonella Typhimurium and Salmonella Enteritidis) or Listeria monocytogenes strains (Scott A, Brie 1, ATCC 6744) for 1 h at room temperature. Soiled conveyor chips were dipped in poultry rinses contaminated with Salmonella or Listeria cocktail and incubated at 10°C for 48 h. The polyurethane with mono-polyester fabric conveyor belt and chip exhibited a higher (Pconveyor belt attached a lower (Pconveyor belts exhibited stronger bacterial adhesion compared with stainless steel. The result suggests the importance of selecting the design and finishes of conveyor belt materials that are most resistant to bacterial attachment.

  17. A portable cell-based optical detection device for rapid detection of Listeria and Bacillus toxins

    Science.gov (United States)

    Banerjee, Pratik; Banada, Padmapriya P.; Rickus, Jenna L.; Morgan, Mark T.; Bhunia, Arun K.

    2005-11-01

    A mammalian cell-based optical biosensor was built to detect pathogenic Listeria and Bacillus species. This sensor measures the ability of the pathogens to infect and induce cytotoxicity on hybrid lymphocyte cell line (Ped-2E9) resulting in the release of alkaline phosphatase (ALP) that can be detected optically using a portable spectrophotometer. The Ped-2E9 cells were encapsulated in collagen gel matrices and grown in 48-well plates or in specially designed filtration tube units. Toxin preparations or bacterial cells were introduced and ALP release was assayed after 3-5 h. Pathogenic L. monocytogenes strains or the listeriolysin toxins preparation showed cytotoxicity ranging from 55% - 92%. Toxin preparations (~20 μg/ml) from B. cereus strains showed 24 - 98% cytotoxicity. In contrast, a non-pathogenic L. innocua (F4247) and a B. substilis induced only 2% and 8% cytotoxicity, respectively. This cell-based detection device demonstrates its ability to detect the presence of pathogenic Listeria and Bacillus species and can potentially be used onsite for food safety or in biosecurity application.

  18. Influences of physicochemical stresses on injury and inactivation behaviour of Listeria innocua

    Directory of Open Access Journals (Sweden)

    Fátima A. Miller

    2017-10-01

    Full Text Available Many minimally processed foods depend on a combination of inhibitory factors to reduce the hazard of foodborne illness. Therefore, inactivation of Listeria innocua was studied according to a 24 factorial experiment designed to draw conclusions about temperature (52.5 °C and 65.0 °C, pH (4.5 and 7.5, water activity (aw=0.95 and 0.99 and solute type (NaCl and glycerol effects. Three different recovery media were used to assess injured cells. Survival data were fitted with a Gompertz-based model and kinetic parameters (shoulder, maximum inactivation rate – kmax, and tail were estimated. Results showed that shoulder was affected by temperature, pH and combined effects; kmax was influenced by all factors and their combinations; and tail was affected by aw, temperature and aw/pH combination. Results demonstrated the potential occurrence of microbial cross-protection survival techniques between the various stresses, e.g. heat and osmolarity. Indeed, this work clearly established that, to avoid hazards, Listeria inactivation must be evaluated with a maximum of environmental factors that undergo alterations. Only thus, appropriate food preservation treatments can be developed and consequently, the safety of food products can be assured.

  19. Different methods to quantify Listeria monocytogenesbiofilms cells showed different profile in their viability

    Directory of Open Access Journals (Sweden)

    Lizziane Kretli Winkelströter

    2015-03-01

    Full Text Available Listeria monocytogenes is a foodborne pathogen able to adhere and to form biofilms in several materials commonly present in food processing plants. The aim of this study was to evaluate the resistance of Listeria monocytogenes attached to abiotic surface, after treatment with sanitizers, by culture method, microscopy and Quantitative Real Time Polymerase Chain Reaction (qPCR. Biofilms of L. monocytogenes were obtained in stainless steel coupons immersed in Brain Heart Infusion Broth, under agitation at 37 °C for 24 h. The methods selected for this study were based on plate count, microscopic count with the aid of viability dyes (CTC-DAPI, and qPCR. Results of culture method showed that peroxyacetic acid was efficient to kill sessile L. monocytogenes populations, while sodium hypochlorite was only partially effective to kill attached L. monocytogenes (p < 0.05. When, viability dyes (CTC/DAPI combined with fluorescence microscopy and qPCR were used and lower counts were found after treatments (p < 0.05. Selective quantification of viable cells of L. monocytogenes by qPCR using EMA revelead that the pre-treatment with EMA was not appropriate since it also inhibited amplification of DNA from live cells by ca. 2 log. Thus, the use of CTC counts was the best method to count viable cells in biofilms.

  20. Adhesion to the host cell surface is sufficient to mediate Listeria monocytogenes entry into epithelial cells

    Science.gov (United States)

    Ortega, Fabian E.; Rengarajan, Michelle; Chavez, Natalie; Radhakrishnan, Prathima; Gloerich, Martijn; Bianchini, Julie; Siemers, Kathleen; Luckett, William S.; Lauer, Peter; Nelson, W. James; Theriot, Julie A.

    2017-01-01

    The intestinal epithelium is the first physiological barrier breached by the Gram-positive facultative pathogen Listeria monocytogenes during an in vivo infection. Listeria monocytogenes binds to the epithelial host cell receptor E-cadherin, which mediates a physical link between the bacterium and filamentous actin (F-actin). However, the importance of anchoring the bacterium to F-actin through E-cadherin for bacterial invasion has not been tested directly in epithelial cells. Here we demonstrate that depleting αE-catenin, which indirectly links E-cadherin to F-actin, did not decrease L. monocytogenes invasion of epithelial cells in tissue culture. Instead, invasion increased due to increased bacterial adhesion to epithelial monolayers with compromised cell–cell junctions. Furthermore, expression of a mutant E-cadherin lacking the intracellular domain was sufficient for efficient L. monocytogenes invasion of epithelial cells. Importantly, direct biotin-mediated binding of bacteria to surface lipids in the plasma membrane of host epithelial cells was sufficient for uptake. Our results indicate that the only requirement for L. monocytogenes invasion of epithelial cells is adhesion to the host cell surface, and that E-cadherin–mediated coupling of the bacterium to F-actin is not required. PMID:28877987