Monitoring the Starvation-Survival Response of Edwardsiella piscicida and E. tarda in Freshwater Microcosms, at Various Temperatures

Edwardsiella piscicida is an important fish pathogen responsible for economic losses in global aquaculture, and E. tarda is also a human zoonotic pathogen. In this study, the survival of E. piscicida and E. tarda strains kept in filtered and sterilized lake water microcosms was investigated during a 20-week period at 7 ◦C, 15 ◦C and 25 ◦C, as well as its pathogenicity retention during a starvation period. E. tarda V43.2 stayed culturable for 6 weeks at 7 ◦C, 9 weeks at 25 ◦C and 12 weeks at 15 ◦C. Both E. piscicida strains (V12.1 and V57.2) stayed culturable even longer, for at least 12 weeks at 7 ◦C, 15 ◦C and 25 ◦C under the same starvation conditions. After Edwardsiella cells entered into the VBNC state, some became shorter and "rounded up," but others aggregated and retained a short rod shape. Aggregates of Edwardsiella cells were common throughout the VBNC period, and a well-formed biofilm was observed for all tested strains at the end of the experiment. The growth capacity of VBNC cells was restored by cultivating microcosm water samples in LB broth at 28 ◦C. Resuscitated E. piscicida cells were as virulent for the European eel as the controls. Natural waters can be a reservoir for Edwardsiella, and its underestimation in environmental samples poses a risk to public health and aquaculture

Pathogenic strains of Shewanella putrefaciens contain plasmids that are absent in the probiotic strain Pdp11

Shewanella putrefaciens Pdp11 is a strain described as a probiotic for use in aquaculture. However, S. putrefaciens includes strains reported to be pathogenic or saprophytic to fish. Although the probiotic trait has been related to the presence of a group of genes in its genome, the existence of plasmids that could determine the probiotic or pathogenic character of this bacterium is unknown. In the present work, we searched for plasmids in several strains of S. putrefaciens that differ in their pathogenic and probiotic character. Under the different conditions tested, plasmids were only found in two of the five pathogenic strains, but not in the probiotic strain nor in the two saprophytic strains tested. Using a workflow integrating Sanger and Illumina reads, the complete consensus sequences of the plasmids were obtained. Plasmids differed in one ORF and encoded a putative replication initiator protein of the repB family, as well as proteins related to plasmid stability and a toxin-antitoxin system. Phylogenetic analysis showed some similarity to functional repB proteins of other Shewanella species. The implication of these plasmids in the probiotic or pathogenic nature of S. putrefaciens is discussed

Micromón València (Universitat de València)

En Julio de 2017 se creó la red SWI@Spain, auspiciada por el grupo de Docencia y Difusión de la Microbiología (DDM) de la Sociedad Española de Microbiología (SEM), para desarrollar la iniciativa internacional Small World Initiative (SWI) en la península ibérica. En la Universitat de València (UV) se constituyó entonces el grupo de Innovación Docente en Microbiología (IDM) para implementar el proyecto a nivel local. Avalados por el Servei de Formació Permanent i Innovació Educativa (SFPIE) de la UV, el grupo ha llevado a cabo diferentes iniciativas relacionadas con el objetivo fundamental del proyecto: divulgar la problemática actual relacionada con el uso inadecuado de antibióticos, el incremento de bacterias resistentes a éstos y la necesidad de encontrar nuevas moléculas con actividad antibacteriana para combatir las infecciones que provocan

Anales de Edafología y Agrobiología Tomo 48 Número 1-2

Efectos de la lluvia ácida: lixiviación de constituyentes en suelos contaminados. Por F. Romero, C. Elejalde y H. Sabin.-- Evaluación de diversas soluciones extractantes de metales Pesados en suelos como indicadoras de las fomas asimilables para las plantas. Por V. Cala, y J. R. Sanchidrian.-- Adsorción de clorprofan (CIPC) por suelos. II. Adsorción por las distintas fracciones granulométricas. Por G. Dios Cancela, J. A. Guillén Alfaro y S. González Careza.-- Influencia del material de partida del suelo y de los tipos de vegetación sobre las lombrices de tierra. Por S. Mato, D. Trigo y D. J. Díaz Cosin.-- Singularidades edafológicas en la comarca La Plana de Requena - Utiel (Valencia). Por R. Boluda Hernández, V. Andréu Pérez, M. Moraleda Esteve y J. Sánchez Díaz.-- Características de los suelos rojos fersialíticos, en la cuenca de México. Por J. F. Cervantes, G. Alfaro Sánchez y M. Meza Sánchez.-- Rasgos micromorfológicos de una catena de suelos afectados por hidromorfía. Por M. Simón, l. Garcfa y J. Fernández.-- Recuperación edáfica de las escombreras de minas de lignito en Galicia. 1)Caracterización de los materiales estériles. Por Mª C. Leirós de la Peña, F. Gil Sotres, M. Carballas Fernández, C. Codesido López, M. a V. González Sangregorio, S. Seoane Lavandeira y F. Guitián Ojea.-- Recuperación edáfica de las escombreras de minas de lignito en Galicia. 2) Influencia del encalado sobre las formas de acidez. Por F. Gil Sotres, Mª C. Leirós de la Peña, Ma V. González Sangregorio, S. Seoane Lavandeira, C. Codesido López y F. Guitián Ojea.-- Influencia de la dolomita en la naturaleza de los suelos. Por J. González Parra, C. González Huecas y A. López Lajilente.-- Producción frente a contaminación en la utilización agrícola de composts urbanos. Por J. M. Murillo, J. M. Hernández, M. Barroso y R. López.-- Efecto del aporte de molibdeno sobre el crecimiento y actividad nitrato -reductasa de Phaseolus vulgaris L. Por M. a S. Martín Gómez y M. a D. Saco Sierra.-- Aplicación de la voltametría de barrido para la determinación de Cd, Pb y Cu en material vegetal. Por R. González Cuesta.-- Diversos aspectos sobre el papel de la materia orgánica humificada en la formación y estabilización de los agregados del suelo. Por C. Fortún y A. Fortún. Influencia de los inviernos cálidos en la adaptación de variedades de melocotonero. Por J. Egea, T. Berenguer, L. Egea y J. E. GarcíaPeer reviewe

Assessment of plasma chitotriosidase activity, CCL18/PARC concentration and NP-C suspicion index in the diagnosis of Niemann-Pick disease type C : A prospective observational study

Niemann-Pick disease type C (NP-C) is a rare, autosomal recessive neurodegenerative disease caused by mutations in either the NPC1 or NPC2 genes. The diagnosis of NP-C remains challenging due to the non-specific, heterogeneous nature of signs/symptoms. This study assessed the utility of plasma chitotriosidase (ChT) and Chemokine (C-C motif) ligand 18 (CCL18)/pulmonary and activation-regulated chemokine (PARC) in conjunction with the NP-C suspicion index (NP-C SI) for guiding confirmatory laboratory testing in patients with suspected NP-C. In a prospective observational cohort study, incorporating a retrospective determination of NP-C SI scores, two different diagnostic approaches were applied in two separate groups of unrelated patients from 51 Spanish medical centers (n = 118 in both groups). From Jan 2010 to Apr 2012 (Period 1), patients with ≥2 clinical signs/symptoms of NP-C were considered 'suspected NP-C' cases, and NPC1/NPC2 sequencing, plasma chitotriosidase (ChT), CCL18/PARC and sphingomyelinase levels were assessed. Based on findings in Period 1, plasma ChT and CCL18/PARC, and NP-C SI prediction scores were determined in a second group of patients between May 2012 and Apr 2014 (Period 2), and NPC1 and NPC2 were sequenced only in those with elevated ChT and/or elevated CCL18/PARC and/or NP-C SI ≥70. Filipin staining and 7-ketocholesterol (7-KC) measurements were performed in all patients with NP-C gene mutations, where possible. In total across Periods 1 and 2, 10/236 (4%) patients had a confirmed diagnosis o NP-C based on gene sequencing (5/118 [4.2%] in each Period): all of these patients had two causal NPC1 mutations. Single mutant NPC1 alleles were detected in 8/236 (3%) patients, overall. Positive filipin staining results comprised three classical and five variant biochemical phenotypes. No NPC2 mutations were detected. All patients with NPC1 mutations had high ChT activity, high CCL18/PARC concentrations and/or NP-C SI scores ≥70. Plasma 7-KC was higher than control cut-off values in all patients with two NPC1 mutations, and in the majority of patients with single mutations. Family studies identified three further NP-C patients. This approach may be very useful for laboratories that do not have mass spectrometry facilities and therefore, they cannot use other NP-C biomarkers for diagnosis