Plant-associated symbiotic Burkholderia species lack hallmark strategies required in mammalian pathogenesis

Burkholderia is a diverse and dynamic genus, containing pathogenic species as well as species that form complex interactions with plants. Pathogenic strains, such as B. pseudomallei and B. mallei, can cause serious disease in mammals, while other Burkholderia strains are opportunistic pathogens, infecting humans or animals with a compromised immune system. Although some of the opportunistic Burkholderia pathogens are known to promote plant growth and even fix nitrogen, the risk of infection to infants, the elderly, and people who are immunocompromised has not only resulted in a restriction on their use, but has also limited the application of non-pathogenic, symbiotic species, several of which nodulate legume roots or have positive effects on plant growth. However, recent phylogenetic analyses have demonstrated that Burkholderia species separate into distinct lineages, suggesting the possibility for safe use of certain symbiotic species in agricultural contexts. A number of environmental strains that promote plant growth or degrade xenobiotics are also included in the symbiotic lineage. Many of these species have the potential to enhance agriculture in areas where fertilizers are not readily available and may serve in the future as inocula for crops growing in soils impacted by climate change. Here we address the pathogenic potential of several of the symbiotic Burkholderia strains using bioinformatics and functional tests. A series of infection experiments using Caenorhabditis elegans and HeLa cells, as well as genomic characterization of pathogenic loci, show that the risk of opportunistic infection by symbiotic strains such as B. tuberum is extremely low

Levantamento da nodulação de leguminosas florestais nativas na região sudeste do Brasil

A survey on nodulation of legume trees was perfomed in (1) Linhares-ES, Reserva Florestal da Companhia Vale do Rio Doce (2) Seropédica-RJ, Estação Florestal de Experimentação Eng°.-Agr°. Mário Xavier and (3) São Paulo, Instituto Florestal de São Paulo. In site (1) and (3) the observations were carried out in the field and with non-inoculated plants in nursery beds, and in place (2) only in nursery beds. The whole root system of young plants or roots attached to old plants were freed of soil, and the nodules assayed individually for nitrogenase activity (C2H2). After the nodule morphology had been observed, the nodules were dried and kept in CaCl2 for Rhizobium isolation. Thirty one out of 43 species of the sub-family Papilionoideae were nodulated, 19 of them reported for the first time. Seven out of 41 species of Caesalpinioideae were nodulated, 6 of them reported for the first time, and 30 out of 35 species of Mimosoideae were nodulated, 11 of them reported for the first time. All the species found with nodules showed nitrogenase activity. Within the new species found with nodules there were 5 genera not reported before: Bowdichia and Poecilanthe (Papilionoideae), Melanoxylon and Moldenhaurea (caesalpinioideae) and Pseudosamanea (Mimosoideae). Among the not nodulating species, 37 had not been reported as such, previously. The nitrogenase activity of individual nodules was variable with species and was in general lower in the species of the sub-family Mimosoideae than the other two sub-families.Foi realizado um levantamento da nodulação de leguminosas florestais na Reserva Florestal da Companhia Vale do Rio Doce, ES, Estação Florestal de Experimentação Eng°.-Agr°. Mário Xavier, Seropédica, RJ e no Instituto Florestal de São Paulo, SP. Após descrição da morfologia dos nódulos, estes foram testados individualmente quanto à atividade da nitrogenase (redução de acetileno), para posterior isolamento de Rhizobium dos nódulos mais ativos. Foram observadas 119 espécies de leguminosas, sendo 43, 41 e 35 das subfamílias Papilionoideae, Caesalpinioideae e Mimosoideae, respectivamente. Das 43 espécies Papilionoideae observadas, 31 apresentaram nódulos, sendo 19 descritos, pela primeira vez, como capazes de nodular. Das 41 espécies Caesalpinioideae, sete apresentaram nódulos, sendo seis em espécies ainda não observadas anteriormente. Das 35 espécies de Mimosoideae, 30 foram observadas com nódulos, sendo onze mencionadas, pela primeira vez, com nódulos. Foram observados também nódulos em cinco novos géneros: Melanoxylon, Moldenhaurea, Bowdichia, Poecilanthe e Pseudosamanea. Trinta e sete das espécies encontradas sem nódulos no tinham sido observadas antes como tal

SARS-CoV-2 reinfection caused by the P.1 lineage in Araraquara city, Sao Paulo State, Brazil

Reinfection by the severe acute respiratory syndrome coronavirus type 2 (SARS-COV-2) has been reported in many countries, suggesting that the virus may continue to circulate among humans despite the possibility of local herd immunity due to massive previous infections. The emergence of variants of concern (VOC) that are more transmissible than the previous circulating ones has raised particular concerns on the vaccines effectiveness and reinfection rates. The P.1 lineage was first identified in December 2020 in Manaus city and is now globally spread. We report the first case of reinfection of SARS-CoV-2 caused by the P.1 variant outside of Manaus. The potential of these new variants to escape naturally and vaccine- induced immunity highlights the need for a global vigilance

The innovation of the symbiosome has enhanced the evolutionary stability of nitrogen fixation in legumes

Nitrogen-fixing symbiosis is globally important in ecosystem functioning and agriculture, yet the evolutionary history of nodulation remains the focus of considerable debate. Recent evidence suggesting a single origin of nodulation followed by massive parallel evolutionary losses raises questions about why a few lineages in the N2 -fixing clade retained nodulation and diversified as stable nodulators, while most did not. Within legumes, nodulation is restricted to the two most diverse subfamilies, Papilionoideae and Caesalpinioideae, which show stable retention of nodulation across their core clades. We characterize two nodule anatomy types across 128 species in 56 of the 152 genera of the legume subfamily Caesalpinioideae: fixation thread nodules (FTs), where nitrogen-fixing bacteroids are retained within the apoplast in modified infection threads, and symbiosomes, where rhizobia are symplastically internalized in the host cell cytoplasm within membrane-bound symbiosomes (SYMs). Using a robust phylogenomic tree based on 997 genes from 147 Caesalpinioideae genera, we show that losses of nodulation are more prevalent in lineages with FTs than those with SYMs. We propose that evolution of the symbiosome allows for a more intimate and enduring symbiosis through tighter compartmentalization of their rhizobial microsymbionts, resulting in greater evolutionary stability of nodulation across this species-rich pantropical legume clade

Metatypical basal cell carcinoma: a clinical review

Background. Metatypical cell carcinoma can be considered as a new entity of skin cancer, being an intermediate typology between basal cell carcinomas and squamous cell carcinomas. The behaviour of the metatypical cell carcinoma lies between these two varieties of skin cancer. It is difficult to perform a differential diagnosis based on morphological and clinical features - therefore it is only possible by accurate histology. Methods. The authors have retrospectively analysed clinical records of 240 patients who were affected by metatypical skin cancer and who were treated by surgery, radiotherapy and chemotherapy. Results. MTC affected more males than females (62.5% vs 37.5%) than males. The most affected site was the cervicofacial area, 71.7%; then the trunk, 10%; the limbs, 9.6%; the scalp 3.7%; and other regions 5%. A recurrence occurred in 24 cases (10%), mainly in head and neck area. Conclusion. In this manuscript, the authors have emphasised the importance of conducting a differential diagnosis, and the importance of the specific treatment for metatypical skin cancer, even though more clinical studies and long-term follow-ups are required before establishing specific guidelines. © 2008 Tarallo et al; licensee BioMed Central Ltd

Observational study on efficacy of negative expiratory pressure test proposed as screening for obstructive sleep apnea syndrome among commercial interstate bus drivers - protocol study

<p>Abstract</p> <p>Background</p> <p>Obstructive sleep apnea (OSA) is a respiratory disease characterized by the collapse of the extrathoracic airway and has important social implications related to accidents and cardiovascular risk. The main objective of the present study was to investigate whether the drop in expiratory flow and the volume expired in 0.2 s during the application of negative expiratory pressure (NEP) are associated with the presence and severity of OSA in a population of professional interstate bus drivers who travel medium and long distances.</p> <p>Methods/Design</p> <p>An observational, analytic study will be carried out involving adult male subjects of an interstate bus company. Those who agree to participate will undergo a detailed patient history, physical examination involving determination of blood pressure, anthropometric data, circumference measurements (hips, waist and neck), tonsils and Mallampati index. Moreover, specific questionnaires addressing sleep apnea and excessive daytime sleepiness will be administered. Data acquisition will be completely anonymous. Following the medical examination, the participants will perform a spirometry, NEP test and standard overnight polysomnography. The NEP test is performed through the administration of negative pressure at the mouth during expiration. This is a practical test performed while awake and requires little cooperation from the subject. In the absence of expiratory flow limitation, the increase in the pressure gradient between the alveoli and open upper airway caused by NEP results in an increase in expiratory flow.</p> <p>Discussion</p> <p>Despite the abundance of scientific evidence, OSA is still underdiagnosed in the general population. In addition, diagnostic procedures are expensive, and predictive criteria are still unsatisfactory. Because increased upper airway collapsibility is one of the main determinants of OSA, the response to the application of NEP could be a predictor of this disorder. With the enrollment of this study protocol, the expectation is to encounter predictive NEP values for different degrees of OSA in order to contribute toward an early diagnosis of this condition and reduce its impact and complications among commercial interstate bus drivers.</p> <p>Trial registration</p> <p><it>Registro Brasileiro de Ensaios Clinicos </it>(local acronym RBEC) [Internet]: Rio de Janeiro (RJ): <it>Instituto de Informaçao Cientifica e Tecnologica em Saude </it>(Brazil); 2010 - Identifier RBR-7dq5xx. Cross-sectional study on efficacy of negative expiratory pressure test proposed as screening for obstructive sleep apnea syndrome among commercial interstate bus drivers; 2011 May 31 [7 pages]. Available from <url>http://www.ensaiosclinicos.gov.br/rg/RBR-7dq5xx/</url>.</p

Postoperative pain management in non-traumatic emergency general surgery : WSES-GAIS-SIAARTI-AAST guidelines

Background Non-traumatic emergency general surgery involves a heterogeneous population that may present with several underlying diseases. Timeous emergency surgical treatment should be supplemented with high-quality perioperative care, ideally performed by multidisciplinary teams trained to identify and handle complex postoperative courses. Uncontrolled or poorly controlled acute postoperative pain may result in significant complications. While pain management after elective surgery has been standardized in perioperative pathways, the traditional perioperative treatment of patients undergoing emergency surgery is often a haphazard practice. The present recommended pain management guidelines are for pain management after non-traumatic emergency surgical intervention. It is meant to provide clinicians a list of indications to prescribe the optimal analgesics even in the absence of a multidisciplinary pain team. Material and methods An international expert panel discussed the different issues in subsequent rounds. Four international recognized scientific societies: World Society of Emergency Surgery (WSES), Global Alliance for Infection in Surgery (GAIS), Italian Society of Anesthesia, Analgesia Intensive Care (SIAARTI), and American Association for the Surgery of Trauma (AAST), endorsed the project and approved the final manuscript. Conclusion Dealing with acute postoperative pain in the emergency abdominal surgery setting is complex, requires special attention, and should be multidisciplinary. Several tools are available, and their combination is mandatory whenever is possible. Analgesic approach to the various situations and conditions should be patient based and tailored according to procedure, pathology, age, response, and available expertise. A better understanding of the patho-mechanisms of postoperative pain for short- and long-term outcomes is necessary to improve prophylactic and treatment strategies.Peer reviewe