Pseudomonas aeruginosa: una bella oportunista / Pseudomonas aeruginosa: a beautiful opportunist

Las bacterias son infinitamente más antiguas que el hombre y se reproducen más rápido, cada quince minutos y en una hora tienen cuatro generaciones, mientras que el hombre necesita un siglo para ello, de modo que en la larga existencia bacteriana somos apenas un minúsculo accidente. Toda la maravillosa maquinaria reunida en una sola bacteria de la especie Pseudomonas aeruginosa no fue planeada contra nosotros, incluyendo señales de quorum, bombas de expulsión, integrones, biofilm y piocinas, ya presentes en su vida natural o planctónica. Su adaptación a la vida nosocomial forzó a estudiarla y la organización de sus múltiples capacidades hace plantear que en su vida hay un propósito, una suerte de "inteligencia bacteriana" en contraposición a la tesis de Jacques Monod que estima la vida en este planeta como fruto del azar y de la necesidad.

Bacteria are infinitely older tan man and reproduce faster, every fifteen minutes and in one hour they have four generations, while man needs a century for have the same, so that in the long bacterial existence we are just a tiny accident. All the wonderful machinery assembled in a single bacterium of the species Pseudomonas aeruginosa it was not planned against us, including quorum sensing, efflux pumps, integrons, biofilm and pyocins, already presents in their natural or planktonic life. Her adaptation to hospital life forced to study this wonderful creature, and the organization of such multiple capacities suggests the existence of a vital purpose, a kind of bacterial intelligence, contrary to Jacques Monod's thesis, which estimate life in this planet as the result of chance and necessity.

Salmonella entérica serovar Enteritidis biofilm lifestyle induces lower pathogenicity and reduces inflammatory response in a murine model compared to planktonic bacteria / Salmonella entérica serovar Enteritidis en biopelícula induce una menor patogenicidad y respuesta inflamatoria en un modelo murino que su contraparte planctónica

Abstract Salmonella enterica serovar Enteritidis (S. Enteritidis) is the most frequent serovar involved in human salmonellosis. It has been demonstrated that about 80% of infections are related to biofilm formation. There is scant information about the pathogenicity of S. Enteritidis and its relationship to biofilm production. In this regard, this study aimed to investigate the differential host response induced by S. Enteritidis biofilm and planktonic lifestyle. To this purpose, biofilm and planktonic bacteria were inoculated to BALB/c mice and epithelial cell culture. Survival studies revealed that biofilm is less virulent than planktonic cells. Reduced signs of intestinal inflammation and lower bacterial translocation were observed in animals inoculated with Salmonella biofilm compared to the planktonic group. Results showed that Salmonella biofilm was impaired for invasion of non-phagocytic cells and induces a lower inflammatory response in vivo and in vitro compared to that of planktonic bacteria. Taken together, the outcome of Salmonella-host interaction varies depending on the bacterial lifestyle.

Resumen Salmonella entérica serovar Enteritidis (S. Enteritidis) es la serovariedad más frecuentemente aislada en la salmonelosis humana. Se ha demostrado que alrededor del 80% de las infecciones están relacionadas con la formación de biopelículas. Sin embargo, la información disponible acerca de la patogenicidad de S. Enteritidis y su relación con la producción de biopelículas es escasa. Este trabajo tuvo como objetivo investigar la respuesta diferencial del huésped frente a S. Enteritidis en sus 2 estilos de vida: biopelícula y planctónico. Para ello, se inocularon bacterias en estado de biopelícula o planctónico en ratones BALB/c y cultivo de células epiteliales. Los estudios de supervivencia revelaron que Salmonella en biopelícula fue menos virulenta que su contraparte planctónica. Los animales inoculados con biopelículas presentaron una mayor conservación estructural del intestino y una menor translocación bacteriana que el grupo planctónico. Asimismo, Salmonella en biopelícula mostró una capacidad deficiente para invadir células no fagocíticas e indujo una menor respuesta inflamatoria in vivo e in vitro que las bacterias planctónicas. Se concluye que el resultado de la interacción Salmonella-huésped depende del estilo de vida bacteriano.

Salmonella enterica serovar Enteritidis biofilm lifestyle induces lower pathogenicity and reduces inflammatory response in a murine model compared to planktonic bacteria.

Salmonellaenterica serovar Enteritidis (S. Enteritidis) is the most frequent serovar involved in human salmonellosis. It has been demonstrated that about 80% of infections are related to biofilm formation. There is scant information about the pathogenicity of S. Enteritidis and its relationship to biofilm production. In this regard, this study aimed to investigate the differential host response induced by S. Enteritidis biofilm and planktonic lifestyle. To this purpose, biofilm and planktonic bacteria were inoculated to BALB/c mice and epithelial cell culture. Survival studies revealed that biofilm is less virulent than planktonic cells. Reduced signs of intestinal inflammation and lower bacterial translocation were observed in animals inoculated with Salmonella biofilm compared to the planktonic group. Results showed that Salmonella biofilm was impaired for invasion of non-phagocytic cells and induces a lower inflammatory response in vivo and in vitro compared to that of planktonic bacteria. Taken together, the outcome of Salmonella-host interaction varies depending on the bacterial lifestyle.

First Detection of Microcystin-LR in the Amazon River at the Drinking Water Treatment Plant of the Municipality of Macapá, Brazil.

Human poisoning by microcystin has been recorded in many countries, including Brazil, where fatal cases have already occurred. The Amazon River is the main source of drinking water in municipalities such as Macapá, where there is no monitoring of cyanobacteria and cyanotoxins. This study investigated the presence of cyanobacteria and cyanotoxins in samples from a drinking water treatment plant (DWTP) that catches water from the Amazon River. The toxin analyses employed ELISA, LC/MS, and molecular screening for genes involved in the production of cyanotoxins. The sampling was carried out monthly from April 2015 to April 2016 at the intake (raw water) and exit (treated water) of the DWTP. This study reports the first detection of microcystin-LR (MC-LR) in the Amazon River, the world's largest river, and in its treated water destined for drinking water purposes in Macapá, Brazil. The cyanobacterial density and MC-LR concentration were both low during the year. However, Limnothrix planctonica showed a density peak (± 900 cells mL-1) in the quarter of June-August 2015, when MC-LR was registered (2.1 µg L-1). Statistical analyses indicate that L. planctonica may produce the microcystin.