Methadone in combination with magnesium, ketamine, lidocaine, and dexmedetomidine improves postoperative outcomes after coronary artery bypass grafting: an observational multicentre study.

BACKGROUND: An optimal pharmacological strategy for fast-track cardiac anesthesia (FTCA) is unclear. This study evaluated the effectiveness and safety of an FTCA program using methadone and non-opioid adjuvant infusions (magnesium, ketamine, lidocaine, and dexmedetomidine) in patients undergoing coronary artery bypass grafting. METHODS: This retrospective, multicenter observational study was conducted across private and public teaching sectors. We studied patients managed by a fast-track protocol or via usual care according to clinician preference. The primary outcome was the total mechanical ventilation time in hours adjusted for hospital, body mass index, category of surgical urgency, cardiopulmonary bypass time and EuroSCORE II. Secondary outcomes included successful extubation within four postoperative hours, postoperative pain scores, postoperative opioid requirements, and the development of postoperative complications. RESULTS: We included 87 patients in the fast-track group and 88 patients in the usual care group. Fast-track patients had a 35% reduction in total ventilation hours compared with usual care patients (p = 0.007). Thirty-five (40.2%) fast-track patients were extubated within four hours compared to 10 (11.4%) usual-care patients (odds ratio: 5.2 [95% CI: 2.39-11.08; p < 0.001]). Over 24 h, fast-track patients had less severe pain (p < 0.001) and required less intravenous morphine equivalent (22.00 mg [15.75:32.50] vs. 38.75 mg [20.50:81.75]; p < 0.001). There were no significant differences observed in postoperative complications or length of hospital stay between the groups. CONCLUSION: Implementing an FTCA protocol using methadone, dexmedetomidine, magnesium, ketamine, lignocaine, and remifentanil together with protocolized weaning from a mechanical ventilation protocol is associated with significantly reduced time to tracheal extubation, improved postoperative analgesia, and reduced opioid use without any adverse safety events. A prospective randomized trial is warranted to further investigate the combined effects of these medications in reducing complications and length of stay in FTCA. TRIALS REGISTRATION: The study protocol was registered in the Australian New Zealand Clinical Trials Registry ( https://www.anzctr.org.au/ACTRN12623000060640.aspx , retrospectively registered on 17/01/2023).

A Multinational Case Series Describing Successful Treatment of Persistent Severe Acute Respiratory Syndrome Coronavirus 2 Infection Caused by Omicron Sublineages With Prolonged Courses of Nirmatrelvir/Ritonavir.

The optimum treatment for persistent infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is not known. Our case series, across 5 hospitals in 3 countries, describes 11 cases where persistent SARS-CoV-2 infection was successfully treated with prolonged courses (median, 10 days [range, 10-18 days]) of nirmatrelvir/ritonavir (Paxlovid). Most cases (9/11) had hematological malignancy and 10 (10/11) had received CD20-depleting therapy. The median duration of infection was 103 days (interquartile range, 85-138 days). The majority (10/11) were hospitalized, and 7 (7/11) had severe/critical disease. All survived and 9 of 11 demonstrated viral clearance, almost half (4/9) of whom received nirmatrelvir/ritonavir as monotherapy. This case series suggests that prolonged nirmatrelvir/ritonavir has a role in treating persistent infection.

The transit of oral premedication beyond the stomach in patients undergoing laparoscopic sleeve gastrectomy: a retrospective observational multicentre study.

BACKGROUND: Antiemetic and analgesic oral premedications are frequently prescribed preoperatively to enhance recovery after laparoscopic sleeve gastrectomy. However, it is unknown whether these medications transit beyond the stomach or if they remain in the sleeve resection specimen, thereby negating their pharmacological effects. METHODS: A retrospective cohort study was performed on patients undergoing laparoscopic sleeve gastrectomy and receiving oral premedication (slow-release tapentadol and netupitant/palonosetron) as part of enhanced recovery after bariatric surgery program. Patients were stratified into the Transit group (premedication absent in the resection specimen) and Failure-to-Transit group (premedication present in the resection specimen). Age, sex, body mass index, and presence of diabetes were compared amongst the groups. The premedication lead time (time between premedications' administration and gastric specimen resection), and the premedication presence or absence in the specimen was evaluated. RESULTS: One hundred consecutive patients were included in the analysis. Ninety-nine patients (99%) were morbidly obese, and 17 patients (17%) had Type 2 diabetes mellitus. One hundred patients (100%) received tapentadol and 89 patients (89%) received netupitant/palonosetron. One or more tablets were discovered in the resected specimens of 38 patients (38%). No statistically significant differences were observed between the groups regarding age, sex, diabetes, or body mass index. The median (Q1‒Q3) premedication lead time was 80 min (57.8‒140.0) in the Failure-to-Transit group and 119.5 min (85.0‒171.3) in the Transit group; P = 0.006. The lead time required to expect complete absorption in 80% of patients was 232 min (95%CI:180‒310). CONCLUSIONS: Preoperative oral analgesia and antiemetics did not transit beyond the stomach in 38% of patients undergoing laparoscopic sleeve gastrectomy. When given orally in combination, tapentadol and netupitant/palonosetron should be administered at least 4 h before surgery to ensure transition beyond the stomach. Future enhanced recovery after bariatric surgery guidelines may benefit from the standardization of premedication lead times to facilitate increased absorption. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry; number ACTRN12623000187640; retrospective registered on 22/02/2023.

ATP synthase evolution on a cross-braced dated tree of life.

The timing of early cellular evolution, from the divergence of Archaea and Bacteria to the origin of eukaryotes, is poorly constrained. The ATP synthase complex is thought to have originated prior to the Last Universal Common Ancestor (LUCA) and analyses of ATP synthase genes, together with ribosomes, have played a key role in inferring and rooting the tree of life. We reconstruct the evolutionary history of ATP synthases using an expanded taxon sampling set and develop a phylogenetic cross-bracing approach, constraining equivalent speciation nodes to be contemporaneous, based on the phylogenetic imprint of endosymbioses and ancient gene duplications. This approach results in a highly resolved, dated species tree and establishes an absolute timeline for ATP synthase evolution. Our analyses show that the divergence of ATP synthase into F- and A/V-type lineages was a very early event in cellular evolution dating back to more than 4 Ga, potentially predating the diversification of Archaea and Bacteria. Our cross-braced, dated tree of life also provides insight into more recent evolutionary transitions including eukaryogenesis, showing that the eukaryotic nuclear and mitochondrial lineages diverged from their closest archaeal (2.67-2.19 Ga) and bacterial (2.58-2.12 Ga) relatives at approximately the same time, with a slightly longer nuclear stem-lineage.

Changes in background characteristics and risk factors among SIDS infants in England: cohort comparisons from 1993 to 2020.

OBJECTIVES: Using the National Child Mortality Database, this work aims to investigate background characteristics and risk factors in the sleeping environment associated with sudden infant death syndrome (SIDS) and compare the prevalence with previous English SIDS case-control studies. DESIGN: Cohort of SIDS in 2020 compared with a combined analysis of two case-control studies conducted in 1993-1996 and 2003-2006. SETTING: England, UK PARTICIPANTS: 138 SIDS deaths in 2020 compared with 402 SIDS deaths and 1387 age-equivalent surviving controls, combined from previous studies. RESULTS: The increased vulnerability of SIDS infants identified in previous studies has become more marked. The infants who died in 2020 were younger (median=66 days (IQR: 34-118) vs 86 days (IQR: 52-148), p=0.003) with an increased prevalence of low birth weight (30.5% vs 21.6%, p=0.04) and preterm births (29.6% vs 19.3%, p=0.012). The excess of socioeconomically deprived families, male infants and high levels of maternal smoking during pregnancy were still evident. Among recent deaths, fewer infants were put down or found on their side; however, there was no significant change in the proportion of infants who were put down (15.6% vs 14.6%, p=0.81) and found prone (40.4% vs 35.3%, p=0.37), despite population wide risk reduction advice over three decades. The proportional increase observed in 2003-2006 of half the deaths occurring while sleeping next to an adult was maintained in 2020, and for the vast majority (90%), this was in hazardous circumstances (adult had consumed alcohol, smoked, slept on a sofa, or the infant was premature or low birth weight and less than 3 months old). More deaths also occurred when there was a disruption in infant care routine compared with previous observations (52.6% vs 20.7%, p<0.001). CONCLUSIONS: A more targeted approach is needed with vulnerable families emphasising the importance of sleeping infants on their back and proactive planning infant sleep when there are disruptions to the normal routine, in particular to avoid hazardous co-sleeping.

On the potential roles of phosphorus in the early evolution of energy metabolism.

Energy metabolism in extant life is centered around phosphate and the energy-dense phosphoanhydride bonds of adenosine triphosphate (ATP), a deeply conserved and ancient bioenergetic system. Yet, ATP synthesis relies on numerous complex enzymes and has an autocatalytic requirement for ATP itself. This implies the existence of evolutionarily simpler bioenergetic pathways and potentially primordial alternatives to ATP. The centrality of phosphate in modern bioenergetics, coupled with the energetic properties of phosphorylated compounds, may suggest that primordial precursors to ATP also utilized phosphate in compounds such as pyrophosphate, acetyl phosphate and polyphosphate. However, bioavailable phosphate may have been notably scarce on the early Earth, raising doubts about the roles that phosphorylated molecules might have played in the early evolution of life. A largely overlooked phosphorus redox cycle on the ancient Earth might have provided phosphorus and energy, with reduced phosphorus compounds potentially playing a key role in the early evolution of energy metabolism. Here, we speculate on the biological phosphorus compounds that may have acted as primordial energy currencies, sources of environmental energy, or sources of phosphorus for the synthesis of phosphorylated energy currencies. This review encompasses discussions on the evolutionary history of modern bioenergetics, and specifically those pathways with primordial relevance, and the geochemistry of bioavailable phosphorus on the ancient Earth. We highlight the importance of phosphorus, not only in the form of phosphate, to early biology and suggest future directions of study that may improve our understanding of the early evolution of bioenergetics.

Prolonged low temperature exposure de-sensitises ABA-induced stomatal closure in soybean, involving an ethylene-dependent process.

Chilling can decrease stomatal sensitivity to abscisic acid (ABA) in some legumes, although hormonal mechanisms involved are unclear. After evaluating leaf gas exchange of 16 European soybean genotypes at 14°C, 6 genotypes representing the range of response were selected. Further experiments combined low (L, 14°C) and high (H, 24°C) temperature exposure from sowing until the unifoliate leaf was visible and L or H temperature until full leaf expansion, to impose four temperature treatments: LL, LH, HL, and HH. Prolonged chilling (LL) substantially decreased leaf water content but increased leaf ethylene evolution and foliar concentrations of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid, indole-3-acetic acid, ABA and jasmonic acid. Across genotypes, photosynthesis linearly increased with stomatal conductance (Gs), with photosynthesis of HH plants threefold higher than LL plants at the same Gs. In all treatments except LL, Gs declined with foliar ABA accumulation. Foliar ABA sprays substantially decreased Gs of HH plants, but did not significantly affect LL plants. Thus low temperature compromised stomatal sensitivity to endogenous and exogenous ABA. Applying the ethylene antagonist 1 methyl-cyclopropene partially reverted excessive stomatal opening of LL plants. Thus, chilling-induced ethylene accumulation may mediate stomatal insensitivity to ABA, offering chemical opportunities for improving seedling survival in cold environments.

The Association of Postoperative Complications and Hospital Costs Following Distal Pancreatectomy.

Background: Understanding the financial implications associated with the complications post-distal pancreatectomy (DP) may be beneficial for the future optimisation of postoperative care pathways and improved cost-efficiency. The primary outcome of this retrospective study was the characterisation of the additional cost associated with postoperative complications following DP. The secondary outcome was the estimation of the prevalence, type and severity of complications post-DP and the determination of which complications were associated with higher costs. Methods: Postoperative complications were retrospectively examined for 62 adult patients undergoing distal pancreatectomy at an Australian university hospital between January 2012 and July 2021. Complications were defined and graded using the Clavien-Dindo (CVD) classification system. In-hospital cost of index admission was calculated using an activity-based costing methodology and was reported in US dollars at 2021 rates. Regression modelling was used to investigate the relationships among selected perioperative variables, complications and costs. Results: 45 patients (72.6%) experienced one or more postoperative complications. The median (IQR) hospital cost in US dollars was 31.6% greater in patients who experienced complications compared to those who experienced no complications ($40,717.8 [27,358.0-59,834.3] vs. $30,946.9 [23,910.8-46,828.1]). Costs for patients with four or more complications were 43.5% higher than for those with three or fewer complications (p = 0.015). Compared to patients with no complications, the median hospital costs increased by 17.1% in patients with minor complications (CVD grade I/II) and by 252% in patients who developed major complication (i.e., CVD grade III/IV) complications. Conclusion: Postoperative complications are a key target for cost-containment strategies. Our findings demonstrate a high prevalence of postoperative complications following distal pancreatectomy with number and severity of postoperative complications being associated with increased hospital costs. (Registered in the Australian New Zealand Clinical Trials Registry [No. ACTRN12622000202763]).

Signatures of hybridization in Trypanosoma brucei.

Genetic exchange among disease-causing micro-organisms can generate progeny that combine different pathogenic traits. Though sexual reproduction has been described in trypanosomes, its impact on the epidemiology of Human African Trypanosomiasis (HAT) remains controversial. However, human infective and non-human infective strains of Trypanosoma brucei circulate in the same transmission cycles in HAT endemic areas in subsaharan Africa, providing the opportunity for mating during the developmental cycle in the tsetse fly vector. Here we investigated inheritance among progeny from a laboratory cross of T. brucei and then applied these insights to genomic analysis of field-collected isolates to identify signatures of past genetic exchange. Genomes of two parental and four hybrid progeny clones with a range of DNA contents were assembled and analysed by k-mer and single nucleotide polymorphism (SNP) frequencies to determine heterozygosity and chromosomal inheritance. Variant surface glycoprotein (VSG) genes and kinetoplast (mitochondrial) DNA maxi- and minicircles were extracted from each genome to examine how each of these components was inherited in the hybrid progeny. The same bioinformatic approaches were applied to an additional 37 genomes representing the diversity of T. brucei in subsaharan Africa and T. evansi. SNP analysis provided evidence of crossover events affecting all 11 pairs of megabase chromosomes and demonstrated that polyploid hybrids were formed post-meiotically and not by fusion of the parental diploid cells. VSGs and kinetoplast DNA minicircles were inherited biparentally, with approximately equal numbers from each parent, whereas maxicircles were inherited uniparentally. Extrapolation of these findings to field isolates allowed us to distinguish clonal descent from hybridization by comparing maxicircle genotype to VSG and minicircle repertoires. Discordance between maxicircle genotype and VSG and minicircle repertoires indicated inter-lineage hybridization. Significantly, some of the hybridization events we identified involved human infective and non-human infective trypanosomes circulating in the same geographic areas.

Revised recommendations on standards and norms for palliative care in Europe from the European Association for Palliative Care (EAPC): A Delphi study.

BACKGROUND: In 2009, the EAPC published recommendations on standards and norms for palliative care in Europe, and a decade later, wished to update them to reflect contemporary practice. AIM: To elicit consensus on standards and norms for palliative care in Europe, taking account of developments since 2009. DESIGN: A Delphi technique used three sequential online survey rounds, and a final expert consultation (EAPC Board). The original 2009 questionnaire with 134 statements was updated with 13 new concepts and practices following a scoping of the literature between 2009 and 2020 (total: 147 statements). SETTING/PARTICIPANTS: One contact of Boards of 52 national European organisations affiliated to the EAPC were invited to participate, with subsequent rounds sent to respondees. The EAPC Board (n = 13) approved final recommendations. RESULTS: In Round 1: 30 organisations (14 organisations × two people, 16 organisations × one person, total n = 44) in 27 countries responded (response rate 58% organisations, 82% countries), Round 2 (n = 40), Round 3 (n = 38). 119 statements reached consensus in Round 1, 9 in Round 2, 7 in Round 3. In total 135/145 statements in five domains (terminology, philosophy, levels, delivery, services) reached consensus (defined as >75% agreement), (122) were original EAPC recommendations with 13 new recommendations included emerging specialisms: neonatal, geriatric and dementia care, and better care practices. Seven statements failed to reach consensus and four were removed as irrelevant or repetition. CONCLUSIONS: Most recommendations on standards and norms for palliative care in Europe remain unchanged since 2009. Evolving concepts in palliative care can be used to support advocacy.

Ultraviolet radiation causes leaf warming due to partial stomatal closure.

Variation in solar ultraviolet radiation induces a wide-range of plant responses from the cellular to whole-plant scale. We demonstrate here for the first time that partial stomatal closure caused by ultraviolet radiation exposure results in significant increases in leaf temperature. Significant leaf warming in response to ultraviolet radiation was consistent in tomato (Solanum lycopersicum L.) across different experimental approaches. In field experiments where solar ultraviolet radiation was attenuated using filters, exposure to ultraviolet radiation significantly decreased stomatal conductance and increased leaf temperature by up to 1.5°C. Using fluorescent lamps to provide ultraviolet radiation treatments, smaller but significant increases in leaf temperature due to decreases in stomatal conductance occurred in both multi-day controlled environment growth room experiments and short-term (< 2 hours) climate cabinet irradiance response experiments. We show that leaf warming due to partial stomatal closure is independent of any direct warming effects of ultraviolet radiation manipulations. We discuss the implications of ultraviolet radiation-induced warming both for horticultural crop production and understanding broader plant responses to ultraviolet radiation.

The Role of Optimism and Psychosocial Factors in Athletes Recovery From ACL Injury: A Longitudinal Study.

Despite a growing interest into the role of psychosocial factors during the recovery period following sports injuries, there remains a paucity of longitudinal studies examining the indirect relationships between psychosocial factors, psychological responses, and recovery outcomes. The purpose of this study was to construct and test a conceptual model which examined the indirect relationships between optimism, psychosocial factors, rehabilitation adherence, and perceived knee function up to 12 months post anterior cruciate ligament (ACL) surgery. A prospective, longitudinal, and repeated measures design was employed, wherein 81 injured athletes (M age 26.89, SD = 7.52) completed measures of optimism, psychosocial factors, rehabilitation adherence, and perceived knee function on seven occasions (pre-surgery to 1 year post-surgery). Bayesian structural equation modeling evaluated the hypothesized indirect relationships proposed within the conceptual model. The main findings from this study was empirical support for a time-ordered, conceptual model which demonstrated that pre-surgery optimism had a significant overall indirect effect on perceived knee function at 12 months post-surgery (sum of indirect; αß = 0.08, post. SD = 0.05, CI [0.01, 0.04]), as well as a specific indirect effect through secondary appraisal at 1 month post-surgery, efficacy at 2 months post-surgery, and rehabilitation adherence at 6 months post-surgery (αß = 0.03, post. SD = 0.03, CI [0.00, 0.10]). Collectively, this study provides support for a number of previously hypothesized, but not empirically examined, indirect relationships between optimism, psychosocial factors and recovery outcomes. In doing so, we provide a conceptual model which has the potential to help guide individualized treatment recommendations, as well as identify individuals at risk of compromised recovery outcomes following ACL surgery.

The structural validity of the IKDC and its relationship with quality of life following ACL reconstruction.

OBJECTIVE: The purpose of this study was to (a) examine the structural validity of the International Knee Documentation Committee Subjective Knee Form in light of previously reported dimensionality issues, and (b) examine the relationships between the IKDC and patients' knee-related quality of life 2-9 years after anterior cruciate ligament (ACL) reconstruction. METHODS: A prospective research design was employed, wherein 319 patients (mean age = 29.07, SD = 9.03) completed the IKDC before surgery, 191 patients (mean age = 29.71, SD = 9.36) completed the IKDC at 6 months post-surgery, and 132 patients (mean age = 34.34, SD = 7.89) completed the IKDC and the Anterior Cruciate Ligament Quality of Life Survey (ACL-QOL) at 2-9 years post-surgery. RESULTS: Bayesian structural equation modeling analysis confirmed the two-factor structure (symptom & knee articulation and activity level) represented the most accurate conceptualization of perceived knee function across the three time-points. Moreover, findings revealed that of the two IKDC subscales pre-operatively, activity level was most strongly associated with long-term quality of life at 2-9 years following surgery, whereas 2-9 years post-operatively, symptoms and knee articulation was most strongly associated with long-term quality of life. CONCLUSIONS: The IKDC provides clinicians with a convenient total score to assess patients' perceived knee function, but its unidimensional factor structure is a poor representation of its items and fails to detect discrepancies in patients' post-operative quality of life, such as the relative importance of perceived knee activity level before reconstructive surgery.

Polymerization in the actin ATPase clan regulates hexokinase activity in yeast.

The actin fold is found in cytoskeletal polymers, chaperones, and various metabolic enzymes. Many actin-fold proteins, such as the carbohydrate kinases, do not polymerize. We found that Glk1, a Saccharomyces cerevisiae glucokinase, forms two-stranded filaments with ultrastructure that is distinct from that of cytoskeletal polymers. In cells, Glk1 polymerized upon sugar addition and depolymerized upon sugar withdrawal. Polymerization inhibits enzymatic activity; the Glk1 monomer-polymer equilibrium sets a maximum rate of glucose phosphorylation regardless of Glk1 concentration. A mutation that eliminated Glk1 polymerization alleviated concentration-dependent enzyme inhibition. Yeast containing nonpolymerizing Glk1 were less fit when growing on sugars and more likely to die when refed glucose. Glk1 polymerization arose independently from other actin-related filaments and may allow yeast to rapidly modulate glucokinase activity as nutrient availability changes.

A new family of cell surface located purine transporters in Microsporidia and related fungal endoparasites.

Plasma membrane-located transport proteins are key adaptations for obligate intracellular Microsporidia parasites, because they can use them to steal host metabolites the parasites need to grow and replicate. However, despite their importance, the functions and substrate specificities of most Microsporidia transporters are unknown. Here, we provide functional data for a family of transporters conserved in all microsporidian genomes and also in the genomes of related endoparasites. The universal retention among otherwise highly reduced genomes indicates an important role for these transporters for intracellular parasites. Using Trachipleistophora hominis, a Microsporidia isolated from an HIV/AIDS patient, as our experimental model, we show that the proteins are ATP and GTP transporters located on the surface of parasites during their intracellular growth and replication. Our work identifies a new route for the acquisition of essential energy and nucleotides for a major group of intracellular parasites that infect most animal species including humans.

The Effect of Nonreversibility on Inferring Rooted Phylogenies.

Most phylogenetic models assume that the evolutionary process is stationary and reversible. In addition to being biologically improbable, these assumptions also impair inference by generating models under which the likelihood does not depend on the position of the root. Consequently, the root of the tree cannot be inferred as part of the analysis. Yet identifying the root position is a key component of phylogenetic inference because it provides a point of reference for polarizing ancestor-descendant relationships and therefore interpreting the tree. In this paper, we investigate the effect of relaxing the unrealistic reversibility assumption and allowing the position of the root to be another unknown. We propose two hierarchical models that are centered on a reversible model but perturbed to allow nonreversibility. The models differ in the degree of structure imposed on the perturbations. The analysis is performed in the Bayesian framework using Markov chain Monte Carlo methods for which software is provided. We illustrate the performance of the two nonreversible models in analyses of simulated data using two types of topological priors. We then apply the models to a real biological data set, the radiation of polyploid yeasts, for which there is robust biological opinion about the root position. Finally, we apply the models to a second biological alignment for which the rooted tree is controversial: the ribosomal tree of life. We compare the two nonreversible models and conclude that both are useful in inferring the position of the root from real biological data.

Investigation of a Cluster of Sequence Type 22 Methicillin-Resistant Staphylococcus aureus Transmission in a Community Setting.

BACKGROUND: Whole-genome sequencing (WGS) has typically been used to confirm or refute hospital/ward outbreaks of methicillin-resistant Staphylococcus aureus (MRSA) identified through routine practice. However, appropriately targeted WGS strategies that identify routinely "undetectable" transmission remain the ultimate aim. METHODS: WGS of MRSA isolates sent to a regional microbiological laboratory was performed as part of a 12-month prospective observational study. Phylogenetic analyses identified a genetically related cluster of E-MRSA15 isolated from patients registered to the same general practice (GP) surgery. This led to an investigation to identify epidemiological links, find additional cases, and determine potential for ongoing transmission. RESULTS: We identified 15 MRSA-positive individuals with 27 highly related MRSA isolates who were linked to the GP surgery, 2 of whom died with MRSA bacteremia. Of the 13 cases that were further investigated, 11 had attended a leg ulcer/podiatry clinic. Cases lacked epidemiological links to hospitals, suggesting that transmission occurred elsewhere. Environmental and staff screening at the GP surgery did not identify an ongoing source of infection. CONCLUSIONS: Surveillance in the United Kingdom shows that the proportion of MRSA bacteremias apportioned to hospitals is decreasing, suggesting the need for greater focus on the detection of MRSA outbreaks and transmission in the community. This case study confirms that the typically nosocomial lineage (E-MRSA15) can transmit within community settings. Our study exemplifies the continued importance of WGS in detecting outbreaks, including those which may be missed by routine practice, and suggests that universal WGS of bacteremia isolates may help detect outbreaks in low-surveillance settings.

Evolution of polymer formation within the actin superfamily.

While many are familiar with actin as a well-conserved component of the eukaryotic cytoskeleton, it is less often appreciated that actin is a member of a large superfamily of structurally related protein families found throughout the tree of life. Actin-related proteins include chaperones, carbohydrate kinases, and other enzymes, as well as a staggeringly diverse set of proteins that use the energy from ATP hydrolysis to form dynamic, linear polymers. Despite differing widely from one another in filament structure and dynamics, these polymers play important roles in ordering cell space in bacteria, archaea, and eukaryotes. It is not known whether these polymers descended from a single ancestral polymer or arose multiple times by convergent evolution from monomeric actin-like proteins. In this work, we provide an overview of the structures, dynamics, and functions of this diverse set. Then, using a phylogenetic analysis to examine actin evolution, we show that the actin-related protein families that form polymers are more closely related to one another than they are to other nonpolymerizing members of the actin superfamily. Thus all the known actin-like polymers are likely to be the descendants of a single, ancestral, polymer-forming actin-like protein.

Decay of the glycolytic pathway and adaptation to intranuclear parasitism within Enterocytozoonidae microsporidia.

Glycolysis and oxidative phosphorylation are the fundamental pathways of ATP generation in eukaryotes. Yet in microsporidia, endoparasitic fungi living at the limits of cellular streamlining, oxidative phosphorylation has been lost: energy is obtained directly from the host or, during the dispersive spore stage, via glycolysis. It was therefore surprising when the first sequenced genome from the Enterocytozoonidae - a major family of human and animal-infecting microsporidians - appeared to have lost genes for glycolysis. Here, we sequence and analyse genomes from additional members of this family, shedding new light on their unusual biology. Our survey includes the genome of Enterocytozoon hepatopenaei, a major aquacultural parasite currently causing substantial economic losses in shrimp farming, and Enterospora canceri, a pathogen that lives exclusively inside epithelial cell nuclei of its crab host. Our analysis of gene content across the clade suggests that Ent. canceri's adaptation to intranuclear life is underpinned by the expansion of transporter families. We demonstrate that this entire lineage of pathogens has lost glycolysis and, uniquely amongst eukaryotes, lacks any obvious intrinsic means of generating energy. Our study provides an important resource for the investigation of host-pathogen interactions and reductive evolution in one of the most medically and economically important microsporidian lineages.