First Stage Solid Propellant Multiply Debris Thermal Analysis

Destruction of a solid rocket stage of a launch vehicle can create a thermal radiation hazard for an aborting crew module. This hazard was assessed for the Constellation Program (Cx) crew and launch vehicle concept. For this concept, if an abort was initiated in first stage flight, the Crew Module (CM) will separate and be pulled away from the malfunctioning launch vehicle via a Launch Abort System (LAS). Having aborted the mission, the launch vehicle will likely be destroyed via a Flight Termination System (FTS) in order to prevent it from errantly traversing back over land and posing a risk to the public. The resulting launch vehicle debris field, composed primarily of first stage solid propellant, poses a threat to the CM. The harsh radiative thermal environment, caused by surrounding burning propellant debris, may lead to CM parachute failure. A methodology, detailed herein, has been developed to address this concern and to quantify the risk of first stage propellant debris leading to the thermal demise of the CM parachutes. Utilizing basic thermal radiation principles, a software program was developed to calculate parachute temperature as a function of time for a given abort trajectory and debris piece trajectory set. Two test cases, considered worst case aborts with regard to launch vehicle debris environments, were analyzed using the simulation: an abort declared at Mach 1 and an abort declared at maximum dynamic pressure (Max Q). For both cases, the resulting temperature profiles indicated that thermal limits for the parachutes were not exceeded. However, short duration close encounters by single debris pieces did have a significant effect on parachute temperature. Therefore while these two test cases did not indicate exceedance of thermal limits, in order to quantify the risk of parachute failure due to radiative effects from the abort environment, a more thorough probability-based analysis using the methodology demonstrated herein must be performed

Global Emergence of Trimethoprim/Sulfamethoxazole Resistance in Stenotrophomonas maltophilia Mediated by Acquisition of sul Genes

The first sul2 genes have been found in S. maltophilia from several different countries

Local Persistence of Novel MRSA Lineage after Hospital Ward Outbreak, Cambridge, UK, 2011–2013

To the Editor: Previously, we reported the use of whole-genome sequencing to investigate a putative methicillin-resistant Staphylococcus aureus (MRSA) outbreak in 2011 in the special care baby unit (SCBU) at the Cambridge University Hospitals National Health Service Foundation Trust (CUH) in the United Kingdom (1). The report identified 26 related cases of infection with or asymptomatic carriage of MRSA and showed that transmission occurred within the SCBU, between mothers on a postnatal ward, and in the community; the outbreak apparently resolved at the end of 2011. The outbreak strain, sequence type (ST) 2371, was of a novel multilocus ST related to the dominant hospital-associated lineage in the UK (ST22, EMRSA-15), but unlike most ST22 strains, this strain was Panton-Valentine leucocidin–positive (2). Since then, ST2371 has been identified as a prevalent communityassociated MRSA clone in Southern India, and sporadic isolates have also been detected by whole-genome sequencing of MRSA in Denmark (3–5)The study was supported by grants from the UKCRC Translational Infection Research (TIR) Initiative, and the Medical Research Council (Grant Number G1000803) with contributions to the Grant from the Biotechnology and Biological Sciences Research Council, the National Institute for Health Research on behalf of the Department of Health, and the Chief Scientist Office of the Scottish Government Health Directorate (to Prof. Peacock); by a Healthcare Infection Society Major Research Grant; and by Wellcome Trust grant number 098051 awarded to the Wellcome Trust Sanger Institute

Genomic surveillance reveals low prevalence of livestock-associated methicillin-resistant Staphylococcus aureus in the East of England

Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) is an emerging problem in many parts of the world. LA-MRSA has been isolated previously from animals and humans in the United Kingdom (UK), but the prevalence is unknown. The aim of this study was to determine the prevalence and to describe the molecular epidemiology of LA-MRSA isolated in the East of England (broadly Cambridge and the surrounding area). We accessed whole genome sequence data for 2,283 MRSA isolates from 1,465 people identified during a 12-month prospective study between 2012 and 2013 conducted in the East of England, United Kingdom. This laboratory serves four hospitals and 75 general practices. We screened the collection for multilocus sequence types (STs) and for host specific resistance and virulence factors previously associated with LA-MRSA. We identified 13 putative LA-MRSA isolates from 12 individuals, giving an estimated prevalence of 0.82% (95% CI 0.47% to 1.43%). Twelve isolates were mecC-MRSA (ten CC130, one ST425 and one ST1943) and single isolate was ST398. Our data demonstrate a low burden of LA-MRSA in the East of England, but the detection of mecC-MRSA and ST398 indicates the need for vigilance. Genomic surveillance provides a mechanism to detect and track the emergence and spread of MRSA clones of human importance.Supported by grants from the UKCRC Translational Infection Research (TIR) Initiative, and the Medical Research Council (Grant Number G1000803) with contributions to the Grant from the Biotechnology and Biological Sciences Research Council, the National Institute for Health Research on behalf of the Department of Health, and the Chief Scientist Ofce of the Scottish Government Health Directorate (to Prof. Peacock); a Hospital Infection Society Major Research Grant, and by Wellcome Trust grant number 098051 awarded to the Wellcome Trust Sanger Institute. Tis work was supported by the Wellcome Trust 201344/Z/16/Z. M.E.T. is a Clinician Scientist Fellow, supported by the Academy of Medical Sciences and the Health Foundation, and by the NIHR Cambridge Biomedical Research Centre

Systematic Surveillance Detects Multiple Silent Introductions and Household Transmission of Methicillin-Resistant Staphylococcus aureus USA300 in the East of England.

BACKGROUND: The spread of USA300 methicillin-resistant Staphylococcus aureus (MRSA) across the United States resulted in an epidemic of infections. In Europe, only sporadic cases or small clusters of USA300 infections are described, and its prevalence in England is unknown. We conducted prospective surveillance for USA300 in the east of England. METHODS: We undertook a 12-month prospective observational cohort study of all individuals with MRSA isolated from community and hospital samples submitted to a microbiology laboratory. At least 1 MRSA isolate from each individual underwent whole-genome sequencing. USA300 was identified on the basis of sequence analysis, and phylogenetic comparisons were made between these and USA300 genomes from the United States. RESULTS: Between April 2012 and April 2013, we sequenced 2283 MRSA isolates (detected during carriage screening and in clinical samples) from 1465 individuals. USA300 was isolated from 24 cases (1.6%). Ten cases (42%) had skin and soft tissue infection, and 2 cases had invasive disease. Phylogenetic analyses identified multiple introductions and household transmission of USA300. CONCLUSIONS: Use of a diagnostic laboratory as a sentinel for surveillance has identified repeated introductions of USA300 in eastern England in 2012-2013, with evidence for limited transmission. Our results show how systematic surveillance could provide an early warning of strain emergence and dissemination.This work was supported by grants from the UK Clinical Research Collaboration Translational Infection Research Initiative, and the Medical Research Council (Grant Number G1000803) with contributions to the Grant from the Biotechnology and Biological Sciences Research Council, the National Institute for Health Research on behalf of the Department of Health, and the Chief Scientist Office of the Scottish Government Health Directorate (to Prof. Peacock); by a Healthcare Infection Society Major Research Grant (to Prof. Peacock), and by Wellcome Trust grant number 098051 awarded to the Wellcome Trust Sanger Institute. MST is a Wellcome Trust Clinical PhD Fellow. MET is a Clinician Scientist Fellow, supported by the Academy of Medical Sciences and the Health Foundation, and by the National Institute for Health Research Cambridge Biomedical Research Centre.This is the final version of the article. It first appeared from Oxford University Press via https://doi.org/10.1093/infdis/jiw16

Longitudinal genomic surveillance of MRSA in the UK reveals transmission patterns in hospitals and the community

Genome sequencing has provided snapshots of the transmission of methicillin-resistant Staphylococcus aureus (MRSA) during suspected outbreaks in isolated hospital wards. Scale-up to populations is now required to establish the full potential of this technology for surveillance. We prospectively identified all individuals over a 12-month period who had at least one MRSA-positive sample processed by a routine diagnostic microbiology laboratory in the East of England, which received samples from three hospitals and 75 general practitioner (GP) practices. We sequenced at least 1 MRSA isolate from 1465 individuals (2282 MRSA isolates) and recorded epidemiological data. An integrated epidemiological and phylogenetic analysis revealed 173 transmission clusters containing between 2 and 44 cases and involving 598 people (40.8%). Of these, 118 clusters (371 people) involved hospital contacts alone, 27 clusters (72 people) involved community contacts alone, and 28 clusters (157 people) had both types of contact. Community- and hospital-associated MRSA lineages were equally capable of transmission in the community, with instances of spread in households, long-term care facilities, and GP practices. Our study provides a comprehensive picture of MRSA transmission in a sampled population of 1465 people and suggests the need to review existing infection control policy and practice.This work was supported by grants from the UK Clinical Research Collaboration Translational Infection Research Initiative and the Medical Research Council (grant no. G1000803) with contributions to the grant from the Biotechnology and Biological Sciences Research Council, the National Institute for Health Research (NIHR) on behalf of the Department of Health, and the Chief Scientist Office of the Scottish Government Health Directorate (to S.J.P.); by a Hospital Infection Society Major Research Grant; by Wellcome Trust grant no. 098051 awarded to the Wellcome Trust Sanger Institute; and by Wellcome Trust 201344/Z/16/Z awarded to F.C. M.S.T. is a Wellcome Trust Clinical PhD fellow. M.E.T. is a Clinician Scientist Fellow, supported by the Academy of Medical Sciences and the Health Foundation and by the NIHR Cambridge Biomedical Research Centr

The effect of genotype and zeranol implantation on performance of steers grazing Mitchell grass pastures in north-west Queensland

[Summary]: Steers of seven different genotypes were purchased from six locations in north-west Queensland and their liveweight performance was compared while grazing Mitchell grass pastures. Only small differences were recorded in liveweight gain between steers containing the approximate breed components of Africander 3 Shorthorn 5, Sahiwal 3 Shorthorn 5, Santa Gertrudis, Brahman 4 British 4, and Brahman 6 British 2. The Bos indicus infused steers had annual liveweight gains of 135 compared with 110kg / head / year in the comparable age Hereford group. Zeranol implantation gave 6% advantage in liveweight gain durin the first 84 d post implantation. This response was consisten across genotype groups. Final liveweight of treated steers was 3% heavier than of untreated steers, although zeranol treatment was given 444 d before slaughter