Motility and Survival of Salmonella Enterica Subspecies Enterica Serovar Enteritidis in Tomato Plants (Solanum lycopersicum L)

The presence of enteropathogens such as Salmonella affects the quality and safety of vegetables that are consumed in a minimally processed state. Worldwide, tomatoes are one of the main vegetables whose raw consumption has caused health alerts. As such, the aim of this study was to determine the motility and survival of Salmonella enterica subspecies enterica serovar Enteritidis on greenhouse-grown tomato plants. A completely randomized experimental design was used, and bacteria were inoculated into the substrate at the time of transplanting as well as by puncturing the plant stem, petiole, and peduncle during the vegetative, flowering, and fruiting stages. Survival was monitored throughout the production cycle; motility was evaluated separately in plant organs separated from the point of inoculation. Salmonella enteritidis survived the 120 days of the experiment both at the point of inoculation and in other organs of the tomato plant. For all treatments, there was a significant difference (P < 0.05) between bacterial counts in the root (12.45 ± 2.52 to 160 ± 4.01 CFU/g), stem (16.10 ± 2.31 to 90.55 ± 3.62 CFU/g), flower (7.0 ± 2.15 to 51.10 ± 3.80 CFU/g), and fruit (8.75 ± 2.38 to 28.2 ± 3.29 CFU/g). The results of the study indicate that Salmonella enteritidis in contact with tomato plants is a latent danger because its ability to enter, survive, and move within tomato plants until reaching the fruit, limits the effectiveness of commonly used disinfection methods, it would potentiate the risk to human health

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Motility and Survival of Salmonella Enterica Subspecies Enterica Serovar Enteritidis in Tomato Plants (Solanum lycopersicum L).

The presence of enteropathogens such as Salmonella affects the quality and safety of vegetables that are consumed in a minimally processed state. Worldwide, tomatoes are one of the main vegetables whose raw consumption has caused health alerts. As such, the aim of this study was to determine the motility and survival of Salmonella enterica subspecies enterica serovar Enteritidis on greenhouse-grown tomato plants. A completely randomized experimental design was used, and bacteria were inoculated into the substrate at the time of transplanting as well as by puncturing the plant stem, petiole, and peduncle during the vegetative, flowering, and fruiting stages. Survival was monitored throughout the production cycle; motility was evaluated separately in plant organs separated from the point of inoculation. Salmonella enteritidis survived the 120 days of the experiment both at the point of inoculation and in other organs of the tomato plant. For all treatments, there was a significant difference (P < 0.05) between bacterial counts in the root (12.45 ± 2.52 to 160 ± 4.01 CFU/g), stem (16.10 ± 2.31 to 90.55 ± 3.62 CFU/g), flower (7.0 ± 2.15 to 51.10 ± 3.80 CFU/g), and fruit (8.75 ± 2.38 to 28.2 ± 3.29 CFU/g). The results of the study indicate that Salmonella enteritidis in contact with tomato plants is a latent danger because its ability to enter, survive, and move within tomato plants until reaching the fruit, limits the effectiveness of commonly used disinfection methods, it would potentiate the risk to human health.

Persistencia, internalización y translocación de Escherichia coli O157:H7, O157:H16 y O105ab en plantas y frutos de tomate (Solanum lycopersicum L.) / Persistence, internalization and translocation of Escherichia coli O157:H7, O157:H16 and O105ab in plants and tomato fruits (Solanum lycopersicum L.)

La presencia de bacterias patógenas, como Escherichia coli, afecta la calidad e inocuidad de las hortalizas que se consumen en fresco y se relaciona con graves problemas de salud. El objetivo de este trabajo fue determinar si 3 cepas diferentes de E. coli tienen la capacidad de penetrar y permanecer en plantas y frutos de tomate. Se siguió un diseño experimental completamente al azar, para lo cual se estableció un cultivo de tomate (variedad «Cid¼) en condiciones de invernadero y se evaluaron 3 tratamientos, T1 (E. coli O157: H7), T2 (E. coli de cultivo de tomate -#91;EcT-#93; O157: H16), T3 (E. coli de cultivo de espinaca -#91;EcH-#93; EcH O105ab) y un testigo T4, con 100 plantas cada uno y 4 formas de inoculación: en el sustrato, en el tallo, en el pecíolo y en el pedúnculo. Se realizaron muestreos en etapa vegetativa, floración, fructificación y madurez fisiológica para cuantificar en placa las UFC/g y saber si las bacterias lograban moverse y recuperarse en la raíz, el tallo, la flor y el fruto. Los grupos filogenéticos a los que correspondieron las bacterias recuperadas fueron confirmados mediante pruebas bioquímicas, serotipificación y PCR. A los 120 días la recuperación de bacterias en la planta fue del 23% (E. coli O157: H7), 28% (EcT O157: H16) y 55% (EcH O105ab) con la inoculación al sustrato, mientras que con la inoculación por punción la recuperación fue (en igual orden) del 5%, 3% y 4% a los 30 días; del 37%, 35% y 30% a los 90 días; y del 42%, 39% y 13% a los 65 días. Las cepas utilizadas mostraron la capacidad de entrar en la planta de tomate y de permanecer en ella y transportarse hasta llegar al fruto, sin producir síntomas que indiquen su presencia.

The presence of pathogenic bacteria, such as Escherichia coli affects the quality and safety of vegetables that are consumed fresh and is associated with serious health problems. The objective of this study was to determine if three different strains of E. coli can penetrate and remain in plants and tomato fruits. A completely randomized experimental design was followed for which a tomato crop ("Cid" variety) was established under greenhouse conditions and three treatments were evaluated, T1 (E. coli O157: H7), T2 (E. coli from tomato cultivation -#91;EcT-#93; O157: H16), T3 (E. coli from spinach cultivation -#91;EcH-#93; O105ab) and a T4 control, with 100 plants each and four forms of inoculation: in the substrate, steam, petiole and the peduncle. Samples were carried out in vegetative stage, flowering, fruiting and physiological maturity to quantify in petri dish CFU/g and know if the bacteria managed to move around and recover in root, stem, flower and fruit. The phylogenetic groups that corresponded to the bacteria recovered were confirmed by biochemical tests, serotyping and PCR. At 120 days the recovery of bacteria in the plant was 23% (E. coli O157: H7), 28% (EcT O157: H16) and 55% (EcH O105ab) whit inoculation to the substrate while the inoculation by puncture the recovery was (in the same order) of 5%, 3%, and 4% at 30 days; 37%, 35% and 30% at 90 days; and 42%, 39% and 13% at 65 days. The strains submit the ability to enter the tomato plant and to stay in it and transported to the fruit, without producing that indicate their presence.

[Persistence, internalization and translocation of Escherichia coli O157:H7, O157:H16 and O105ab in plants and tomato fruits (Solanum lycopersicum L.)]. / Persistencia, internalización y translocación de Escherichia coli O157:H7, O157:H16 y O105ab en plantas y frutos de tomate (Solanum lycopersicum L.).

The presence of pathogenic bacteria, such as Escherichia coli affects the quality and safety of vegetables that are consumed fresh and is associated with serious health problems. The objective of this study was to determine if three different strains of E. coli can penetrate and remain in plants and tomato fruits. A completely randomized experimental design was followed for which a tomato crop ("Cid" variety) was established under greenhouse conditions and three treatments were evaluated, T1 (E. coli O157:H7), T2 (E. coli from tomato cultivation [EcT] O157:H16), T3 (E. coli from spinach cultivation [EcH] O105ab) and a T4 control, with 100 plants each and four forms of inoculation: in the substrate, steam, petiole and the peduncle. Samples were carried out in vegetative stage, flowering, fruiting and physiological maturity to quantify in petri dish CFU/g and know if the bacteria managed to move around and recover in root, stem, flower and fruit. The phylogenetic groups that corresponded to the bacteria recovered were confirmed by biochemical tests, serotyping and PCR. At 120 days the recovery of bacteria in the plant was 23% (E. coli O157:H7), 28% (EcT O157:H16) and 55% (EcH O105ab) whit inoculation to the substrate while the inoculation by puncture the recovery was (in the same order) of 5%, 3%, and 4% at 30 days; 37%, 35% and 30% at 90 days; and 42%, 39% and 13% at 65 days. The strains submit the ability to enter the tomato plant and to stay in it and transported to the fruit, without producing that indicate their presence.

Detección de Ca Liberibacter solanacearum y fitoplasmas en cultivo de papa (Solanum tuberosum L) en el Valle de Toluca / Detection of Ca Liberibacter solanacearum and phytoplasma in potato crop (Solanum tuberosum L) in Toluca Valley

En México y Centro América se han detectado tubérculos de papa con manchado interno. Recientemente en Texas EUA a esta enfermedad se le ha denominado "Zebra Chip" (ZC) o rayado de la papa, los síntomas foliares se asemejan al síndrome denominado "Punta Morada de la Papa" (PMP) o enfermedad del "amarillamiento por psilidos" la cual es asociada con la presencia de "Candidatus Liberibacter solanacearum". El objetivo de esta investigación fue detectar la presencia de esta bacteria y de fitoplasmas en plantas de papa que presentaban la coloración purpura de los foliolos. Durante el ciclo primavera - verano 2011 y 2012 se hizo un muestreo en los municipios de Tenango del Valle, Zinacantepec, Villa de Allende y San José del Rincón, del Estado de México. La detección de ambos patógenos se realizó mediante la reacción en cadena de la polimerasa (PCR) con los iniciadores específicos para fitoplasmas: P1/P7, R16mF2/R16mR1 y para Ca Liberibacter solanacearum: OA2/Oi2c, resultando el 35,8% de las plantas positivas para fitoplasmas y el 11,6% para la bacteria. Los resultados indican que en algunas regiones productoras de papa del Estado de México, los dos presuntos agentes causales del síndrome de PMP, fitoplasmas y Ca. Liberibacter solanacearum, pueden estar asociados.

In Mexico and Central America have been detected stained potato tubers with internal browning; recently in Texas, USA, this disease has been called "Zebra Chip" (ZC) or striped potato, foliar symptoms resemble the syndrome called "Potato Purple Top" (PPT) or "psyllid yellows" disease which is associated with the presence of "Candidatus Liberibacter solanacearum". The aim of the current work was to detect the presence of this bacterium and phytoplasma in potato plants with purple top symptoms. During 2011 and 2012 Spring - Summer cycle, a directed sampling was carried out in Tenango del Valle, Zinacantepec, Villa de Allende and San José del Rincón, State of México. The detection of both pathogens was performed by Polymerase Chain Reaction (PCR) with specific primers for phytoplasmas: P1/ P7, R16mF2/R16mR1 and for Ca Liberacter solanacearum: OA2/Oi2c, being 35,8 % from the positive plants for phytoplasmas and 11,6 % for this bacterium. These results indicated that in some areas these two PPT syndrome suspected causative agents, phytoplasmas and Ca. Liberibacter solanacearum, could be associated in the State of Mexico potato-producing region.