Sinorhizobium fredii HH103 RirA is required for oxidative stress resistance and efficient symbiosis with Soybean

Members of Rhizobiaceae contain a homologue of the iron-responsive regulatory protein RirA. In different bacteria, RirA acts as a repressor of iron uptake systems under iron-replete conditions and contributes to ameliorate cell damage during oxidative stress. In Rhizobium leguminosarum and Sinorhizobium meliloti, mutations in rirA do not impair symbiotic nitrogen fixation. In this study, a rirA mutant of broad host range S. fredii HH103 has been constructed (SVQ780) and its free-living and symbiotic phenotypes evaluated. No production of siderophores could be detected in either the wild-type or SVQ780. The rirA mutant exhibited a growth advantage under iron-deficient conditions and hypersensitivity to hydrogen peroxide in iron-rich medium. Transcription of rirA in HH103 is subject to autoregulation and inactivation of the gene upregulates fbpA, a gene putatively involved in iron transport. The S. fredii rirA mutant was able to nodulate soybean plants, but symbiotic nitrogen fixation was impaired. Nodules induced by the mutant were poorly infected compared to those induced by the wild-type. Genetic complementation reversed the mutant’s hypersensitivity to H2O2, expression of fbpA, and symbiotic deficiency in soybean plants. This is the first report that demonstrates a role for RirA in the Rhizobium-legume symbiosis.Andalucian Government Grant No. P11-CVI-7500Spanish Government Grant Nos. BIO2013-42801-P and BIO2016-78409-REuropean Regional Development Funds (ERDF)VPPI (V Plan Propio de Investigación) of University of Seville

Regulation and symbiotic significance of nodulation outer proteins secretion in Sinorhizobium fredii HH103

In this work we show that the Sinorhizobium fredii HH103 ttsI gene is essential for the expression of the tts genes and secretion of nodulation outer proteins (Nops). Moreover, we demonstrate for the first time, to our knowledge, that the nod box preceding ttsI is necessary for Nops secretion. TtsI is responsible for the transcriptional activation of nopX, nopA, rhcJ and rhcQ. We confirm that the S. fredii HH103 ttsI gene is activated by NodD1 and repressed by NolR. In contrast, NodD2 is not involved in the regulation of ttsI expression. Despite the dependence of expression of both ttsI and nodA on NodD1 and flavonoids, clear differences in the capacity of some flavonoids to activate these genes were found. The expression of the ttsI and nodA genes was also sensitive to differences in the pH of the media. Secretion of Nops in the ttsI mutant could not be complemented with a DNA fragment containing the ttsI gene and its nod box, but it was restored when a plasmid harbouring the ttsI, rhcC2 and y4xK genes was transferred to the mutant strain. The symbiotic effect of Nops secretion was host-dependent but independent of the type of nodule formed by the host legume. Nops are beneficial in the symbiosis with Glycine max and Glycyrrhiza uralensis, and detrimental in the case of the tropical legume Erythrina variegata

Exopolysaccharide Production by Sinorhizobium fredii HH103 Is Repressed by Genistein in a NodD1-Dependent Manner

In the rhizobia-legume symbiotic interaction, bacterial surface polysaccharides, such as exopolysaccharide (EPS), lipopolysaccharide (LPS), K-antigen polysaccharide (KPS) or cyclic glucans (CG), appear to play crucial roles either acting as signals required for the progression of the interaction and/or preventing host defence mechanisms. The symbiotic significance of each of these polysaccharides varies depending on the specific rhizobialegume couple. In this work we show that the production of exopolysaccharide by Sinorhizobium fredii HH103, but not by other S. fredii strains such as USDA257 or NGR234, is repressed by nod gene inducing flavonoids such as genistein and that this repression is dependent on the presence of a functional NodD1 protein. In agreement with the importance of EPS for bacterial biofilms, this reduced EPS production upon treatment with flavonoids correlates with decreased biofilm formation ability. By using quantitative RT-PCR analysis we show that expression of the exoY2 and exoK genes is repressed in late stationary cultures of S. fredii HH103 upon treatment with genistein. Results presented in this work show that in S. fredii HH103 EPS production is regulated just in the opposite way than other bacterial signals such as Nod factors and type 3 secreted effectors: it is repressed by flavonoids and NodD1 and enhanced by the nod repressor NolR. These results are in agreement with our previous observations showing that lack of EPS production by S. fredii HH103 is not only non-detrimental but even beneficial for symbiosis with soybeanMinisterio de Ciencia e Investigación BIO2011-30229-C02-01Junta de Andalucía P11-CVI-750

A pyrF auxotrophic mutant of Sinorhizobium fredii HH103 impaired in its symbiotic interaction with soybean and other legumes

Transposon Tn5-Mob mutagenesis allowed the selection of a Sinorhizobium fredii HH103 mutant derivative (SVQ 292) that requires the presence of uracil to grow in minimal media. The mutated gene, pyrF, codes for an orotidine-5 ́- monophosphate decarboxylase (EC 4.1.1.23). Mutant SVQ 292 and its parental prototrophic mutant HH103 showed similar Nod-factor and lipopolysaccharide profiles. The symbiotic properties of mutant SVQ 292 were severely impaired with all legumes tested. Mutant SVQ 292 formed small ineffective nodules on Cajanus cajan and abnormal nodules (pseudonodules) unable to fix nitrogen on Glycine max (soybean), Macroptitlium atropurpureum, Indigofera tinctoria, and Desmodium cana-dense. It also did not induce any macroscopic response in Macrotyloma axillare roots. The symbiotic capacity of SVQ 292 with soybean was not enhanced by the addition of uracil to the plant nutritive solution

Prevalence and Risk Factors for Multidrug-Resistant Organisms Colonization in Long-Term Care Facilities Around the World: A Review

Elderly people confined to chronic care facilities face an increased risk of acquiring infections by multidrug-resistant organisms (MDROs). This review presents the current knowledge of the prevalence and risk factors for colonization by MDROs in long-term care facilities (LTCF), thereby providing a useful reference to establish objectives for implementing successful antimicrobial stewardship programs (ASPs). We searched in PubMed and Scopus for studies examining the prevalence of MDROs and/or risk factors for the acquisition of MDROs in LTCF. One hundred and thirty-four studies published from 1987 to 2020 were included. The prevalence of MDROs in LTCF varies between the different continents, where Asia reported the highest prevalence of extended-spectrum ß-lactamase (ESBL) Enterobacterales (71.6%), carbapenem resistant (CR) Enterobacterales (6.9%) and methicillin-resistant Staphylococcus aureus (MRSA) (25.6%) and North America the highest prevalence to MDR Pseudomonas aeruginosa (5.4%), MDR Acinetobacter baumannii (15.0%), vancomycin-resistant Enterococcus spp. (VRE) (4.0%), and Clostridioides difficile (26.1%). Furthermore, MDRO prevalence has experienced changes over time, with increases in MDR P. aeruginosa and extended spectrum ß-lactamase producing Enterobacterales observed starting in 2015 and decreases of CR Enterobacterales, MDR A. baumannii, VRE, MRSA and C. difficile. Several risk factors have been found, such as male sex, chronic wounds, the use of medical devices, and previous antibiotic use. The last of these aspects represents one of the most important modifiable factors for reducing colonization with MDROs through implementing ASPs in LTCF.The study was funded by the Instituto de Salud Carlos III, the Spanish Ministry of Economy, Industry, and Competitiveness (grant number: PI17-02195) and was partially funded by the European Development Regional Fund “A way to achieve Europe”. A.R.V. and A.B.G.G. are supported by the Subprograma Río Hortega, Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Ciencia, Innovación y Universidades, Spain. A.R.V. grant number: CM18/00122. A.B.G.G. grant number: CM19/00029. C.M.G. and J.C.C.R. are supported by the Instituto de Salud Carlos III (grant number: PI17-02195) and co-financed by European Development Regional Fund ‘A way to achieve Europe’ ERDF, Spanish Network for the Research in Infectious Diseases (REIPI RD16/0016/0009).G.P. is supported by the Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Economía, Industria y Competitividad, Spanish Network for Research in Infectious Diseases (REIPI RD16/0016/0001)- co-financed by European Development Regional Fund “A way to achieve Europe”, Operative program Intelligent Growth 2014–2020. M.E.P.I. is a postdoctoral researcher belonging to the program “Nicolás Monardes” (C1-0038-2019), Servicio Andaluz de Salud, Junta de Andalucía, Spain. J.M.C. received funding for research from Plan Nacional de I+D+i 2013–2016 and Instituto de Salud Carlos III, Subdireccion General de Redes y Centros de InvestigacionCooperativa, Ministry of Economy, Industry and Competitiveness, Spanish Network for Research in Infectious Diseases (REIPI RD16/0016/0001, RD16/0016/0009), co-financed by the European Development Regional Fund “A way to achieve Europe”.Ye

The rkpU gene of Sinorhizobium fredii HH103 is required for bacterial K-antigen polysaccharide production and for efficient nodulation with soybean but not with cowpea

In this work, the role of the rkpU and rkpJ genes in the production of the K-antigen polysaccharides (KPS) and in the symbiotic capacity of Sinorhizobium fredii HH103, a broad host-range rhizobial strain able to nodulate soybean and many other legumes, was studied. The rkpJ- and rkpU-encoded products are orthologous to Escherichia coli proteins involved in capsule export. S. fredii HH103 mutant derivatives were contructed in both genes. To our knowledge, this is the first time that the role of rkpU in KPS production has been studied in rhizobia. Both rkpJ and rkpU mutants were unable to produce KPS. The rkpU derivative also showed alterations in its lipopolysaccharide (LPS). Neither KPS production nor rkpJ and rkpU expression was affected by the presence of the flavonoid genistein. Soybean (Glycine max) plants inoculated with the S. fredii HH103 rkpU and rkpJ mutants showed reduced nodulation and clear symptoms of nitrogen starvation. However, neither the rkpJ nor the rkpU mutants were significantly impaired in their symbiotic interaction with cowpea (Vigna unguiculata). Thus, we demonstrate for the first time to our knowledge the involvement of the rkpU gene in rhizobial KPS production and also show that the symbiotic relevance of the S. fredii HH103 KPS depends on the specific bacterium–legume interaction

Increased risk of MAFLD and liver fibrosis in inflammatory bowel disease independent of classic metabolic risk factors

ackground & Aims There is conflicting evidence regarding the prevalence of and risk factors for metabolic-associated fatty liver disease (MAFLD) in patients with inflammatory bowel disease (IBD). We aimed to determine MAFLD prevalence and risk factors in IBD patients. Methods Cross-sectional, case-control study included all consecutive IBD patients treated at 2 different university hospitals. Controls were subjects randomly selected from the general population and matched by age, sex, type 2 diabetes status, and body mass index in a 1:2 ratio. MAFLD was confirmed by controlled attenuation parameter. Liver biopsies were collected when MAFLD with significant liver fibrosis was suspected. In addition, age- and fibrosis stage-paired non-IBD patients with biopsy-proven MAFLD served as a secondary control group. Results Eight hundred thirty-one IBD patients and 1718 controls were included. The prevalence of MAFLD and advanced liver fibrosis (transient elastography ≥9.7 kPa) was 42.00% and 9.50%, respectively, in IBD patients and 32.77% and 2.31%, respectively, in the general population (P < .001). A diagnosis of IBD was an independent predictor of MAFLD (adjusted odds ratio, 1.99; P < .001) and an independent risk factor for advanced liver fibrosis (adjusted odds ratio, 5.55; P < .001). Liver biopsies were obtained from 40 IBD patients; MAFLD was confirmed in all cases, and fibrosis of any degree was confirmed in 25 of 40 cases (62.5%). Body mass index and type 2 diabetes prevalence were significantly lower in IBD-MAFLD patients than in severity-paired patients with biopsy-proven MAFLD. Conclusions MAFLD and liver fibrosis are particularly prevalent in IBD patients, regardless of the influence of classic metabolic risk factors.Acknowledgements: The authors report funding support from the Spanish Instituto de Salud Carlos III-FEDER Grant (FIS - PI18/01304) related to this manuscript

SARS-CoV-2 viral load in nasopharyngeal swabs is not an independent predictor of unfavorable outcome

The aim was to assess the ability of nasopharyngeal SARS-CoV-2 viral load at frst patient’s hospital evaluation to predict unfavorable outcomes. We conducted a prospective cohort study including 321 adult patients with confrmed COVID-19 through RT-PCR in nasopharyngeal swabs. Quantitative Synthetic SARS-CoV-2 RNA cycle threshold values were used to calculate the viral load in log10 copies/mL. Disease severity at the end of follow up was categorized into mild, moderate, and severe. Primary endpoint was a composite of intensive care unit (ICU) admission and/or death (n= 85, 26.4%). Univariable and multivariable logistic regression analyses were performed. Nasopharyngeal SARS-CoV-2 viral load over the second quartile (≥7.35 log10 copies/mL, p = 0.003) and second tertile (≥ 8.27 log10 copies/mL, p = 0.01) were associated to unfavorable outcome in the unadjusted logistic regression analysis. However, in the fnal multivariable analysis, viral load was not independently associated with an unfavorable outcome. Five predictors were independently associated with increased odds of ICU admission and/or death: age≥ 70 years, SpO2, neutrophils > 7.5 × ­103 /µL, lactate dehydrogenase≥ 300 U/L, and C-reactive protein≥ 100 mg/L. In summary, nasopharyngeal SARS-CoV-2 viral load on admission is generally high in patients with COVID-19, regardless of illness severity, but it cannot be used as an independent predictor of unfavorable clinical outcome

Dendritic cell deficiencies persist seven months after SARS-CoV-2 infection

Virgen del Rocío Hospital COVID-19 Working Team José Miguel Cisneros, Sonsoles Salto-Alejandre, Judith Berastegui-Cabrera, Pedro Camacho-Martínez, Carmen Infante-Domínguez, Marta Carretero-Ledesma, Juan Carlos Crespo-Rivas, Eduardo Márquez, José Manuel Lomas, Claudio Bueno, Rosario Amaya, José Antonio Lepe, Jerónimo Pachón, Elisa Cordero, Javier Sánchez-Céspedes, Manuela Aguilar-Guisado, Almudena Aguilera, Clara Aguilera, Teresa Aldabo-Pallas, Verónica Alfaro-Lara, Cristina Amodeo, Javier Ampuero, María Dolores Avilés, Maribel Asensio, Bosco Barón-Franco, Lydia Barrera-Pulido, Rafael Bellido-Alba, Máximo Bernabeu-Wittel, Candela Caballero-Eraso, Macarena Cabrera, Enrique Calderón, Jesús Carbajal-Guerrero, Manuela Cid-Cumplido, Yael Corcia-Palomo, Juan Delgado, Antonio Domínguez-Petit, Alejandro Deniz, Reginal Dusseck-Brutus, Ana Escoresca-Ortega, Fátima Espinosa, Nuria Espinosa, Michelle Espinoza, Carmen Ferrándiz-Millón, Marta Ferrer, Teresa Ferrer, Ignacio Gallego-Texeira, Rosa Gámez-Mancera, Emilio García, Horacio García-Delgado, Manuel García-Gutiérrez, María Luisa Gascón-Castillo, Aurora González-Estrada, Demetrio González, Carmen Gómez-González, Rocío González-León, Carmen Grande-Cabrerizo, Sonia Gutiérrez, Carlos Hernández-Quiles, Inmaculada Concepción Herrera-Melero, Marta Herrero-Romero, Luis Jara, Carlos Jiménez-Juan, Silvia Jiménez-Jorge, Mercedes Jiménez-Sánchez, Julia Lanseros-Tenllado, Carmina López, Isabel López, Álvaro López-Barrios, Luis F. López-Cortés, Rafael Luque-Márquez, Daniel Macías-García, Guillermo Martín-Gutiérrez, Luis Martín-Villén, José Molina, Aurora Morillo, María Dolores Navarro-Amuedo, Dolores Nieto-Martín, Francisco Ortega, María Paniagua-García, Amelia Peña-Rodríguez, Esther Pérez, Manuel Poyato, Julia Praena-Segovia, Rafaela Ríos, Cristina Roca-Oporto, Jesús F. Rodríguez, María Jesús Rodríguez-Hernández, Santiago Rodríguez-Suárez, Ángel Rodríguez-Villodres, Nieves Romero-Rodríguez, Ricardo Ruiz, Zida Ruiz de Azua, Celia Salamanca, Sonia Sánchez, Víctor Manuel Sánchez-Montagut, César Sotomayor, Alejandro Suárez Benjumea & Javier ToralSevere Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2 infection induces an exacerbated inflammation driven by innate immunity components. Dendritic cells (DCs) play a key role in the defense against viral infections, for instance plasmacytoid DCs (pDCs), have the capacity to produce vast amounts of interferon-alpha (IFN-α). In COVID-19 there is a deficit in DC numbers and IFN-α production, which has been associated with disease severity. In this work, we described that in addition to the DC deficiency, several DC activation and homing markers were altered in acute COVID-19 patients, which were associated with multiple inflammatory markers. Remarkably, previously hospitalized and nonhospitalized patients remained with decreased numbers of CD1c+ myeloid DCs and pDCs seven months after SARS-CoV-2 infection. Moreover, the expression of DC markers such as CD86 and CD4 were only restored in previously nonhospitalized patients, while no restoration of integrin β7 and indoleamine 2,3-dyoxigenase (IDO) levels were observed. These findings contribute to a better understanding of the immunological sequelae of COVID-19.This work was supported by Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades Junta de Andalucia (research Project CV20-85418), Consejeria de salud Junta de Andalucia (Research Contract RH-0037-2020 to JV) the Instituto de Salud Carlos III (CP19/00159 to AGV, FI17/00186 to MRJL, FI19/00083 to MCGC, CM20/00243 to APG, and COV20/00698 to support COHVID-GS) and the Red Temática de Investigación Cooperativa en SIDA (RD16/0025/0020 and RD16/0025/0026), which is included in the Acción Estratégica en Salud, Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica, 2008 to 2011 and 2013 to 2016, Instituto de Salud Carlos III, Fondos FEDER. ERM was supported by the Spanish Research Council (CSIC).Peer reviewe

Clinical and Ecological Impact of an Educational Program to Optimize Antibiotic Treatments in Nursing Homes (PROA-SENIOR): A Cluster, Randomized, Controlled Trial and Interrupted Time-Series Analysis

[Background] Antimicrobial stewardship programs (ASPs) are recommended in nursing homes (NHs), although data are limited. We aimed to determine the clinical and ecological impact of an ASP for NHs.[Methods] We performed a cluster, randomized, controlled trial and a before–after study with interrupted time-series analyses in 14 NHs for 30 consecutive months from July 2018 to December 2020 in Andalusia, Spain. Seven facilities implemented an ASP with a bundle of 5 educational measures (general ASP) and 7 added 1-to-1 educational interviews (experimental ASP). The primary outcome was the overall use of antimicrobials, calculated monthly as defined daily doses (DDD) per 1000 resident days (DRD).[Results] The total mean antimicrobial consumption decreased by 31.2% (−16.72 DRD; P = .045) with respect to the preintervention period; the overall use of quinolones and amoxicillin–clavulanic acid dropped by 52.2% (P = .001) and 42.5% (P = .006), respectively; and the overall prevalence of multidrug-resistant organisms (MDROs) decreased from 24.7% to 17.4% (P = .012). During the intervention period, 12.5 educational interviews per doctor were performed in the experimental ASP group; no differences were found in the total mean antimicrobial use between groups (−14.62 DRD; P = .25). Two unexpected coronavirus disease 2019 waves affected the centers increasing the overall mean use of antimicrobials by 40% (51.56 DRD; P < .0001).[Conclusions] This study suggests that an ASP for NHs appears to be associated with a decrease in total consumption of antimicrobials and prevalence of MDROs. This trial did not find benefits associated with educational interviews, probably due to the coronavirus disease 2019 pandemic.[Clinical Trials Registration] NCT03543605.Peer reviewe