A murine systemic model for shigellosis

Summary Shigella spp. are pathogenic bacteria responsible for bacillary dysentery in humans. The major lesions in colonic mucosa are intense inflammation with apoptosis of macrophages and release of pro-inflammatory cytokines. The study of shigellosis is hindered by the natural resistance of rodents to oral infection with Shigella. Therefore, animal models exploit other routes of infection. Here, we describe a novel murine model in which animals receive shigellae via the caudal vein. Mice infected with 5 × 106 (LD50) virulent shigellae died at 48 h post infection, whereas animals receiving non-invasive mutants survived. The liver is the main target of infection, where shigellae induce microgranuloma formation. In mice infected with invasive bacteria, high frequency of apoptotic cells is observed within hepatic microgranulomas along with significant levels of mRNA for pro-inflammatory cytokines such as IL-1β, IL-18, IL-12 and IFN-γ. Moreover, in the blood of these animals high levels of IL-6 and transaminases are detected. Our results demonstrate the intravenous model is suitable for pathogenicity studies and useful to explore the immune response after Shigella infection

¿Por qué es importante compostar la cama de pollo antes de utilizarla como enmienda en la producción hortícola?

Reflexionamos acerca del uso de cama de pollo en la frutihorticultura en el marco de la Buenas Prácticas Agrícolas en virtud de su significativo aporte a las características físicas, físico-químicas y biológicas del sueloEEA BalcarceFil: Okada, Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina.Fil: Rizzo, Pedro Federico. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentina.Fil: Pérez, Débora. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina.Fil: Carciochi, Walter. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Carciochi, Walter. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina.Fil: Pellegrini, Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina. Grupo de Investigación en Ingeniería en Alimentos; Argentina.Fil: Ponce, Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Grupo de Investigación en Ingeniería en Alimentos; Argentina.Fil: Lavallen, Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones en Producción, Sanidad y Ambiente; Argentina.Fil: Dopchiz, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones en Producción, Sanidad y Ambiente; Argentina.Fil: Young, Brian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto De Investigación Microbiología y Zoología Agrícola; Argentina.Fil: Di Martino, Ana María. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; Argentina.Fil: Borracci, Sebastián Emilio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Agencia de Extensión Rural Otamendi; Argentina

Alternativas de compostaje de cama de pollo para su utilización como enmienda de suelo

PosterLa cama de pollo (CP) sin tratar seutiliza como abono en la producciónhortícola. En el presente trabajo se compostó CP proveniente de una producción de pollos parrilleros, dispuestas en pilas de 3 m2 con los siguientes tratamientos por triplicado: CAP19: pilas estáticas con aireación pasiva, C:N=19: CAM19: pilas con aireación mecánica, C:N=19; y CAM30: pilas con aireación mecánica y agregado de viruta para una C:N=30:1. En los tratamientos CAM19 y CAM30 se alcanzaron temperaturas > 55ºC por más de 36 días, lo que asegura una correcta higienización del material. Dentro de los parámetros biológicos, no se detectaron Salmonella sp. ni Ascaris lumbricoides en la CP ni en los compost. El CSA y CSA:N disminuyeron en todos lostratamientos. El pH aumentó en CAM19 yCAM30, mientras que en CAP19 no varió. En todos los tratamientos se redujo CE (60%), N total (45%), NH4+ (95%), NNH4+:N-NO3- (88%) y la toxicidad (76%), respectode la CP inicial. En CAM30 el agregado de viruta de madera con conservantes produjo una acumulación de As y Cr. Se concluye que el compostaje de la CP mediante volteos mecánicos permitió obtener un producto sanitizado, maduro, estable y con menor fitotoxicidad. No se recomienda el agregado de viruta como fuente de C, debido a que se puede incorporar metales pesados en exceso.EEA BalcarceFil: Okada, Elena. Instituto Nacional de Tecnología Agropecuaria (INTA) Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina.Fil: Pérez, Débora. Instituto Nacional de Tecnología Agropecuaria (INTA) Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina.Fil: Carciochi, Walter. Instituto Nacional de Tecnología Agropecuaria (INTA) Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina.Fil: Carciochi Walter. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Pellegrini, María Celeste. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Grupo de Investigación en Ingeniería en Alimentos; Argentina.Fil: Ponce, Alejandra, Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Grupo de Investigación en Ingeniería en Alimentos; Argentina.Fil: Lavallén, Carla. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata; Argentina. Instituto de Investigaciones en Producción, Sanidad y Ambiente; Argentina.Fil: Dopchiz, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata; Argentina. Instituto de Investigaciones en Producción, Sanidad y Ambiente; Argentina.Fil: Young, Brian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; Argentina.Fil: Franco, María del Rosario. Instituto Nacional de Tecnología Agropecuaria (INTA) Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina.Fil: Di Martino, Ana María. Instituto Nacional de Tecnología Agropecuaria (INTA) Estación Experimental Agropecuaria Pergamino; Argentina.Fil: Rizzo, Pedro. Instituto Nacional de Tecnología Agropecuaria (INTA) Estación Experimental Agropecuaria Mendoza; Argentina

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

Peer reviewe

Characterization of putative virulence determinants and their role in the pathogenici of Helicobacter pylori

Dottorato di ricerca in farmacologia, farmacognosia e tossicologia. 12 ciclo. A.a. 1996-99. Tutori Giuseppe Del Giudice e Gabriella Mazzanti. Coordinatore Bruno SilvestriniConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Analysis of Virulence and Inflammatory Potential of Shigella flexneri Purine Biosynthesis Mutants

Several Shigella flexneri mutants with defects in aromatic amino acid and/or purine biosynthesis have been evaluated as vaccines in humans or in animal models. To be suitable as a vaccine, a mutant has to show virulence attenuation, minimal reactogenicity, and a good immunogenic potential in animal models. With this aim, we have constructed five S. flexneri 5 (wild-type strain M90T) mutants with inactivation of one or two of the loci purEK, purHD, and guaBA, governing early or late steps of purine biosynthesis. The mutants have been analyzed in vitro in cell cultures and in vivo in the Sereny test and in the murine pulmonary model of shigellosis. M90T guaBA, M90T guaBA purEK, M90T guaBA purHD, and M90T purHD purEK gave a negative result in the Sereny test. In contrast, in the murine pulmonary model all of the strains had the same 50% lethal dose as the wild type, except M90T guaBA purHD, which did not result in death of the animals. Nevertheless, bacterial counts in infected lungs, immunohistochemistry, and reverse transcription-PCR analysis of mRNAs for tumor necrosis factor alpha (TNF-α), gamma interferon (IFN-γ), interleukin-1β (IL-1β), IL-6, IL-12, and inducible nitric oxide synthase (iNOS) revealed significant differences among the strains. At 72 h postinfection, M90T guaBA purHD still induced proinflammatory cytokines and factors such as IL-1β, IL-6, TNF-α, and iNOS, along with cytokines such as IL-12 and IFN-γ. Moreover, in the absence of evident lesions in murine tissues, this mutant highly stimulated major histocompatibility complex class II expression, showing a significant ability to activate the innate immunity of the host

Selection of Shigella flexneri candidate virulence genes specifically induced in bacteria resident in host cell cytoplasm

We describe an in vivo expression technology (IVET)- like approach, which uses antibiotic resistance for selection, to identify Shigella flexneri genes specifically activated in bacteria resident in host cell cytoplasm. This procedure required construction of a promoter-trap vector containing a synthetic operon between the promoterless chloramphenicol acetyl transferase (cat) and lacZ genes and construction of a library of plasmids carrying transcriptional fusions between S. flexneri genomic fragments and the cat–lacZ operon. Clones exhibiting low levels (<10 μg ml−1) of chloramphenicol (Cm) resistance on laboratory media were analysed for their ability to induce a cytophatic effect – plaque – on a cell monolayer, in the presence of Cm. These clones were assumed to carry a plasmid in which the cloned fragment acted as a promoter/gene which is poorly expressed under laboratory conditions. Therefore, only strains harbouring fusion-plasmids in which the cloned promoter was specifically activated within host cytoplasm could survive within the cell monolayer in the presence of Cm and give a positive result in the plaque assay. Pai (plaque assay induced) clones, selected following this procedure, were analysed for intracellular (i) b-galactosidase activity, (ii) proliferation in the presence of Cm, and (iii) Cm resistance. Sequence analysis of Pai plasmids revealed genes encoding proteins of three functional classes: external layer recycling, adaptation to microaerophilic environment and gene regulation. Sequences encoding unknown functions were also trapped and selected by this new IVET-based protocol