Cell-free synthesis of the Salmonella specific broad host range bacteriophage, felixO1.

Phage-based biocontrol of foodborne Salmonella is limited by the requisite use of Salmonella to propagate the phages. This limitation can be circumvented by producing Salmonella phages using a cell-free gene expression system (CFE) with a non-pathogenic chassis. Here, we produce the Salmonella phage felixO1 using an E. coli-based CFE system.

A ToxIN homolog from Salmonella enterica serotype Enteritidis impairs bacteriophage infection.

AIMS: To determine if the bacteriophage abortive infection system ToxIN is present in foodborne Salmonella and if it protects against infection by bacteriophages specific to enteric bacteria. METHODS AND RESULTS: A set of foodborne Salmonella enteritidis isolates from a 2010 eggshell outbreak was identified via BLASTN (basic local alignment search tool nucleotide) queries as harboring a close homolog of ToxIN, carried on a plasmid with putative mobilization proteins. This homolog was cloned into a plasmid vector and transformed into the laboratory strain Salmonella typhimurium LT2 and tested against a set of Salmonella-specific phages (FelixO1, S16, Sp6, LPST153, and P22 HT105/1 int-201). ToxIN reduced infection by FelixO1, S16, and LPST153 by ∼1-4 log PFU ml-1 while reducing the plaque size of Sp6. When present in LT2 and Escherichia coli MG1655, ToxIN conferred cross-genus protection against phage isolates, which infect both bacteria. Finally, the putative ToxIN plasmid was found in whole-genome sequence contigs of several Salmonella serovars, pathogenic E. coli, and other pathogenic enterobacteria. CONCLUSIONS: Salmonella and E. coli can resist infection by several phages via ToxIN under laboratory conditions; ToxIN is present in foodborne pathogens including Salmonella and Shiga-toxigenic E. coli.

The Outer Membrane Cytochrome OmcA Is Essential for Infection of Shewanella oneidensis by a Zebrafish-Associated Bacteriophage.

The microbiota-the mixture of microorganisms in the intestinal tract of animals-plays an important role in host biology. Bacteriophages are a prominent, though often overlooked, component of the microbiota. The mechanisms that phage use to infect susceptible cells associated with animal hosts, and the broader role they could play in determining the substituents of the microbiota, are poorly understood. In this study, we isolated a zebrafish-associated bacteriophage, which we named Shewanella phage FishSpeaker. This phage infects Shewanella oneidensis strain MR-1, which cannot colonize zebrafish, but it is unable to infect Shewanella xiamenensis strain FH-1, a strain isolated from the zebrafish gut. Our data suggest that FishSpeaker uses the outer membrane decaheme cytochrome OmcA, which is an accessory component of the extracellular electron transfer (EET) pathway in S. oneidensis, as well as the flagellum to recognize and infect susceptible cells. In a zebrafish colony that lacks detectable FishSpeaker, we found that most Shewanella spp. are sensitive to infection and that some strains are resistant to infection. Our results suggest that phage could act as a selectivity filter for zebrafish-associated Shewanella and show that the EET machinery can be targeted by phage in the environment. IMPORTANCE Phage exert selective pressure on bacteria that influences and shapes the composition of microbial populations. However, there is a lack of native, experimentally tractable systems for studying how phage influence microbial population dynamics in complex communities. Here, we show that a zebrafish-associated phage requires both the outer membrane-associated extracellular electron transfer protein OmcA and the flagellum to infect Shewanella oneidensis strain MR-1. Our results suggest that the newly discovered phage-FishSpeaker-could exert selective pressure that restricts which Shewanella spp. colonize zebrafish. Moreover, the requirement of OmcA for infection by FishSpeaker suggests that the phage preferentially infects cells that are oxygen limited, a condition required for OmcA expression and an ecological feature of the zebrafish gut.

Convergent evolution and horizontal gene transfer in Arctic Ocean microalgae.

Microbial communities in the world ocean are affected strongly by oceanic circulation, creating characteristic marine biomes. The high connectivity of most of the ocean makes it difficult to disentangle selective retention of colonizing genotypes (with traits suited to biome specific conditions) from evolutionary selection, which would act on founder genotypes over time. The Arctic Ocean is exceptional with limited exchange with other oceans and ice covered since the last ice age. To test whether Arctic microalgal lineages evolved apart from algae in the global ocean, we sequenced four lineages of microalgae isolated from Arctic waters and sea ice. Here we show convergent evolution and highlight geographically limited HGT as an ecological adaptive force in the form of PFAM complements and horizontal acquisition of key adaptive genes. Notably, ice-binding proteins were acquired and horizontally transferred among Arctic strains. A comparison with Tara Oceans metagenomes and metatranscriptomes confirmed mostly Arctic distributions of these IBPs. The phylogeny of Arctic-specific genes indicated that these events were independent of bacterial-sourced HGTs in Antarctic Southern Ocean microalgae.

Is releasing pulleys during flexor tendon repair "part and parcel"? Narrative review of the current evidence.

BACKGROUND: The complex hand flexors pulleys system is essential in achieving efficient flexor tendons' function. Previous cadaveric studies demonstrated that A2 and A4 are the crucial pulleys in maintaining normal digits biomechanics. Realistically, the preservation of A2 and A4 pulleys during repairing flexor tendon laceration in zones one and two can be extremely challenging. We review the current published evidence in this article to answer the question of whether releasing the pulleys cause bowstringing or affects clinical outcomes. METHODS: Literature search of the available databases. RESULTS: There was no published comparative evidence. Retrospective case series have reported that no clinical bowstringing was noted after releasing flexor pulleys during flexor tendon repairs. Outcomes have been reported according to Tang and or Strickland criteria to assess range of motion (ROM). No functional hand scores or patients' satisfactions scores have been reported. CONCLUSION: Releasing flexor pulleys during tendon repair to allow access or prevent impingement of the repaired tendon does not seem to cause bowstringing or affect outcome based on the limited available evidence. Future research is needed. LEVEL OF EVIDENCE: Level 4.

How to manage scaphoid waist fractures? Introduction of pragmatic imaging efficient pathway and literature review of the recent evidence.

INTRODUCTION AND OBJECTIVE: The scaphoid bone sustains about 90 % of carpal bone fractures and is the second-highest bone at risk of post-traumatic osteonecrosis. Delayed diagnosis and treatment could lead to non-union and advanced carpal bones collapse. This study aimed to introduce an imaging efficient and practical scaphoid waist fracture management pathway (SWFMP) and measure its efficacy in clinical practice. MATERIALS AND METHODS: The SWFMP was introduced in January 2020. Suspected occult fractures were approached by early orthopaedic clinical assessment and subsequent urgent MRI scan without repeating scaphoid X-rays. Scaphoid waist fractures displaced < 2 mm were treated with 8 weeks below elbow cast immobilization followed by CT scan if delayed union was suspected. Waist fractures displaced > 2 mm were managed with surgical fixation. Adult patients referred from the emergency department (ED) to the Virtual Fracture Clinic (VFC) with acute scaphoid injury from January 2019 to October 2019 (Pre SWFMP, n = 29), were identified and compared to those managed from January 2020 to October 2020 (Post SWFMP, n = 33). RESULTS: Mean age was 37.9 (SD = 20.61) and 36.2 (SD = 17.06) years in the pre-SWFMP and post-SWFMP cohorts respectively. Fiften patients (51.7%) had the right side affected in the pre-SWFMP cohort and twenty-three patients (69.7%) in the post-SWFMP cohort. Scaphoid X-rays requested by ED have increased from 19 (65.5%) to 31 (94%) and repeated X-rays reduced from 17 (58.6%) to 10 (30.3%) after the introduction of the SWFMP. Mean wrist cast immobilization for patients without scaphoid fractures dropped from 16.9 days (SD = 5.57) to 3.6 days (SD = 6.24) after the SWFMP (p = 0.001). In the pre-SWFMP cohort, 24 patients had no fracture, 4 achieved full healing and 1 developed non-union. In the post-SWFMP cohort, 29 patients had no fracture, 1 achieved full union and delayed union was detected in 3 patients at 8 weeks. CONCLUSIONS: The SWFMP has improved the clinical practice by reducing unnecessary ionizing radiation, unnecessary cast immobilization, and by using a timely fracture fixation intervention.

Contemporary accuracy of death certificates for coding prostate cancer as a cause of death: Is reliance on death certification good enough? A comparison with blinded review by an independent cause of death evaluation committee.

BACKGROUND: Accurate cause of death assignment is crucial for prostate cancer epidemiology and trials reporting prostate cancer-specific mortality outcomes. METHODS: We compared death certificate information with independent cause of death evaluation by an expert committee within a prostate cancer trial (2002-2015). RESULTS: Of 1236 deaths assessed, expert committee evaluation attributed 523 (42%) to prostate cancer, agreeing with death certificate cause of death in 1134 cases (92%, 95% CI: 90%, 93%). The sensitivity of death certificates in identifying prostate cancer deaths as classified by the committee was 91% (95% CI: 89%, 94%); specificity was 92% (95% CI: 90%, 94%). Sensitivity and specificity were lower where death occurred within 1 year of diagnosis, and where there was another primary cancer diagnosis. CONCLUSIONS: UK death certificates accurately identify cause of death in men with prostate cancer, supporting their use in routine statistics. Possible differential misattribution by trial arm supports independent evaluation in randomised trials.

Exostoses, enchondromatosis and metachondromatosis; diagnosis and management.

We describe a 5 years old girl who presented to the multidisciplinary skeletal dysplasia clinic following excision of two bony lumps from her fingers. Based on clinical examination, radiolographs and histological results an initial diagnosis of hereditary multiple exostosis (HME) was made. Four years later she developed further lumps which had the radiological appearance of enchondromas. The appearance of both exostoses and enchondromas suggested a possible diagnosis of metachondromatosis. Genetic testing revealed a splice site mutation at the end of exon 11 on the PTPN11 gene, confirming the diagnosis of metachondromatosis. While both single or multiple exostoses and enchondromas occur relatively commonly on their own, the appearance of multiple exostoses and enchondromas together is rare and should raise the differential diagnosis of metachondromatosis. Making this diagnosis is important as the lesions in metachondromatosis may spontaneously resolve and therefore surgical intervention is often unnecessary. We discuss the diagnostic findings, genetic causes, treatment and prognosis of this rare condition of which less than thirty cases have previously been reported.

Post-poliomyelitis syndrome as a possible viral disease.

This review summarizes current concepts on post-polio syndrome (PPS), a condition that may arise in polio survivors after partial or complete functional recovery followed by a prolonged interval of stable neurological function. PPS affects 15-20 million people worldwide. Epidemiological data are reported, together with the pathogenic pathways that possibly lead to the progressive degeneration and loss of neuromuscular motor units. As a consequence of PPS, polio survivors experience new weakness, generalized fatigue, atrophy of previously unaffected muscles, and a physical decline that may culminate in the loss of independent life. Emphasis is given to the possible pathogenic role of persistent poliovirus infection and chronic inflammation. These factors could contribute to the neurological and physical decline in polio survivors. A perspective is then given on novel anti-poliovirus compounds and monoclonal antibodies that have been developed to contribute to the final phases of polio eradication. These agents could also be useful for the treatment or prevention of PPS. Some of these compounds/antibodies are in early clinical development. Finally, current clinical trials for PPS are reported. In this area, the intravenous infusion of normal human immunoglobulins appears both feasible and promising.

Botulinum Toxin in the management of hitchhiker's toe.

INTRODUCTION: Hyperextension of the extensor hallucis longus (EHL) muscle is a well recognised disabling sequel of either pyramidal or extrapyramidal lesions causing what is known as striated or hitchhiker's toe. Surgery was the only effective strategy to manage EHL hyperextension before botulinum toxin's use to manage muscular dystonia and spasticity became widely popular. METHODS: A multicentre retrospective study. A standard proforma was sent to specialists in neurological rehabilitation dealing routinely with this problem. The data was analysed using descriptive statistics. RESULTS: Four consultants and two trainees representing five separate neurological rehabilitation services agreed to participate in the study. Full data was available from the 29 proformas completed. The subjects were 15 females with an age range between 20 and 78 years (mean 58.7). Stroke was the primary diagnosis in 18 subjects. Four subjects had bilateral involvement. 16 subjects had either an associated foot drop or equino varus deformity. Dysport® was used in 15 subjects with an average dose of 170 units per injection and Botox® in the other 14 with an average dose of 65 units. The treatment was effective in 24 subjects (83%). All patients receiving Dysport® responded to the treatment. Whilst 5 Botox® treated patients failed to respond to it (35% failure rate). Most of the non respondents seemed to receive insufficient doses of Botox® (below 60 units). Surgical management was successful in 3 out of the 5 non respondent cases. CONCLUSION: Botilinum Toxin is an effective and safe method to manage hitchhicker's toe. In our study the conversion ratio between Dysport® and Botox® was 2.5:1. Third of the patients receiving Botox® failed to respond to the treatment most probably due to insufficient doses used.

Foliar residue dynamics of azadirachtins following direct stem injection into white and green ash trees for control of emerald ash borer.

BACKGROUND: Azadirachtins are natural insecticides derived from the neem tree. The emerald ash borer (EAB) is an exotic invasive insect pest that infests various ash tree species and has the potential for significant economic, aesthetic and ecological impacts throughout North America. The initial translocation and foliar residue dynamics of azadirachtins were examined following direct injection into white and green ash trees growing in urban scenarios as a potential control for EAB. RESULTS: Substantial concentrations of azadirachtins A and B [mean maxima > 0.98 mg kg(-1) fresh weight (f.w.)] were observed within 2 days of injecting a specifically designed formulation of azadirachtins. Foliar residues declined exponentially through time, with half-life estimates ranging from 5.1 to 12.3 days. At the time of leaf senescence, foliar residue levels approximated 0.01 mg kg(-1) f.w., strongly mitigating the potential effects of non-target biota in soil or aquatic compartments. CONCLUSION: The magnitude and duration of exposures observed in this field study were considered to be above the thresholds required for biological effectiveness against both larval and adult life stages of EAB. Results support the use of azadirachtins as an environmentally acceptable systemic insecticide for control of EAB and protection of high-value ash trees in urban environments.

Azadirachtin: an effective systemic insecticide for control of Agrilus planipennis (Coleoptera: Buprestidae).

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), an invasive pest discovered in North America in 2002, is now well established and threatens ash (Fraxinus spp.) trees throughout the continent. Experiments were conducted to 1) examine the efficacy of an alternative natural pesticide, azadirachtin, to control emerald ash borer, and 2) determine foliar uptake and dissipation patterns after systemic injections of azadirachtin into trunks of small (2.2 cm diameter at breast height [dbh]), uninfested green ash trees. We found no evidence of mortality of adult beetles. In contrast, fewer larvae completed their development at dose levels > or = 1.7 mg (AI)/cm dbh and development ceased beyond the second instar at dose levels > or = 13.6 mg (AI)/cm dbh. Substantial concentrations (11.2 microg/g dry mass [SD = 7.55]) of azadirachtin were present in leaves within 7 d of treatment. After rapid initial uptake, concentrations in leaves declined logarithmically during the 55 d after injection. A similar pattern was observed in a separate experiment that examined the uptake and translocation of azadirachtin in larger green ash trees (22 cm dbh) treated with 250 mg (AI) /cm dbh with the EcoJect injection system. In another experiment, recently infested plantation green ash trees treated with doses > or = 40 mg (AI)/cm dbh had significant reductions in adult emergence approximately 1 yr postinjection. Given the inhibition of larval development, reduction of adult emergence, and the occurrence of foliar residues at biologically active concentrations, we conclude that azadirachtin is effective in protecting ash trees from emerald ash borer.

A ganglion cyst at the elbow causing superficial radial nerve compression: a case report.

INTRODUCTION: We report a rare case of a ganglion cyst at the elbow causing neurological symptoms by stretching the superficial radial nerve alone. Ganglia associated with radial nerve palsy at the elbow have been reported previously involving the deep branch of the posterior interosseous nerve and the superficial radial nerve, but not the superficial radial nerve alone. CASE PRESENTATION: A 45-year-old woman presented with a 4-month history of a painful lump in the anterior aspect of her left elbow associated with altered sensation in the dorsoradial aspect of her left hand. There was no history of trauma or any exacerbating factors. On examination the altered sensation was in the superficial radial nerve distribution and she had a positive Tinel's sign over the site of the swelling which was located over the anterior aspect of the radiocapitellar joint. CONCLUSION: The unique clinical symptoms and signs of our diagnosis of superficial radial nerve compression were confirmed by magnetic resonance imaging and then operative findings.