An in vitro evaluation of the efficacy of tedizolid: implications for the treatment of skin and soft tissue infections

Skin and soft tissue infections (SSTI) are among the most commonly occurring infections and evidence suggests that these are increasing world-wide. The aetiology is diverse, but Staphylococcus aureus predominate and these are often resistant to antimicrobials that were previously effective. Tedizolid is a new oxazolidinone-class antibacterial indicated for the treatment of adults with SSTI caused by Gram-positive pathogens, including S. aureus. The aim of this study was to evaluate the in vitro efficacy of tedizolid in comparison to other clinically used antibacterials against antibiotic sensitive- and resistant-staphylococci, grown in planktonic cultures and as biofilms reflecting the growth of the microorganism during episodes of SSTI. Against a panel of 66 clinical staphylococci, sensitivity testing revealed that a lower concentration of tedizolid was required to inhibit the growth of staphylococci compared to linezolid, vancomycin and daptomycin; with the tedizolid MIC being 8-fold (S. aureus) or 4-fold (S. epidermidis) below that obtained for linezolid. In addition, cfr+ linezolid-resistant strains remained fully susceptible to tedizolid. Against S. aureus biofilms, 10×MIC tedizolid was superior or comparable with 10×MIC comparator agents in activity, and superior to 10×MIC linezolid against those formed by S. epidermidis (65 vs. 33% reduction, respectively). Under flow-conditions both oxazolidinones at 10×MIC statistically out-performed vancomycin in their ability to reduce the viable cell count within a S. aureus biofilm with fewer the 12% of cells surviving compared to 63% of cells. In conclusion, tedizolid offers a realistic lower-dose alternative agent to treat staphylococcal SSTI, including infections caused by multi-drug resistant strains

The Impact of Urbanization on Macroinvertebrate Communities of Creeks Within Western Georgia

Urbanization is a major cause of stream impairment in the United States, altering stream ecological integrity in a variety of ways. While control of point source pollution has largely improved over the last twenty years, the control of non-point source pollution has proved to be more of a challenge. Urbanization in the area surrounding streams has been linked with elevated levels of sediment, heavy metals, organic matter, and nutrients within streams, as well as with other negative effects. Examining the macroinvertebrate communities within streams has proven to be an effective indicator of the effects of urbanization on water quality. This study used that concept to evaluate the health of nine sites on three tributaries of the Chattahoochee River around and within Columbus, Georgia, for the effects of such urbanization. The results of this study indicated that the sites on the less urbanized Upatoi Creek had the healthiest representation of benthic macroinvertebrates, and consequently they were classified as having good to fair water quality, an attribute that needs to be conserved. In contrast, the lower and upper sites on Standing Boy Creek, which is located in a developing urban area, had fairly poor water quality, and were most in need in remediation efforts. To a lesser extent, the lower and middle sites on Bull Creek, which had notably higher percent urban land use than all other sites, also had somewhat degraded aquatic communities within them as well. Despite the less urbanized Upatoi Creek sites having comparatively superior water quality, no significant correlation was found between percent urbanization and any changes in metric values. Presumably, many factors in addition to urbanization caused the differences in macroinvertebrate populations found between sites. Other factors that likely acted in addition to percent urban land use to affect the benthic macroinvertebrate communities were percent agricultural land use and an ongoing drought. The ongoing drought in the area appeared to affect biotic values the most, as those values increased as sampling continued throughout the year, indicating that water quality was decreasing. Comparisons between sites were further complicated by physical differences among sites and a lack of a significant gradient in percent land use between the majority of sites. Due to the many factors influencing the water quality within these nine locations, additional biomonitoring efforts are suggested to further specify the exact effects of the increasing urbanization and other factors on streams within the city of Columbus and its suburbs

Characterisation of coagulase-negative staphylococci associated with endocarditis

Coagulase-negative staphylococci are major aetiological agents of prosthetic valve endocarditis and an occasional cause of native valve disease. It is currently unclear how this group of usually avirulent microorganisms produces an infection associated with high rates of morbidity and mortality. The aim of this thesis was to investigate whether there are specific genotypes and/or phenotypes of coagulase-negative staphylococci with a propensity to cause infective endocarditis and to investigate any identified virulence factors as markers of infection. In this study, strains of endocarditis-related coagulase-negative staphylococci were genotyped by determining their macrorestriction genomic profile using pulsed-field gel electrophoresis. The strains were also investigated for phenotypic characteristics that predisposed the microorganisms to infect heart valves. By comparing coagulase-negative staphylococcal strains recovered from endocarditis patients with isolates from other significant infections (prosthetic device-related osteomyelitis and catheter-associated sepsis), no specific genotype or phenotype with a predilection to cause endocarditis was identified. However, the majority of the endocarditis-associated and other infection strains expressed the potential virulence factors lipase and esterase. Another approach to the investigation of virulence determinants used patient's serum to screen a Staphylococcus epidermidis NCTC 11047 genomic DNA library for cellular and secreted staphylococcal products that were expressed in vivo. The characterisation of two clones, which reacted with serum collected from a S. epidermidis-related endocarditis patient identified a staphylococcal pyruvate dehydrogenase complex E2 subunit and a novel secreted protein with homology to a Staphylococcus aureus staphyloxanthin biosynthesis protein and a secreted protein of unknown function described in Staphylococcus carnosus. Investigation of the secreted protein previously undetected in S. epidermidis, termed staphylococcal secretory antigen (SsaA), identified a potential marker of S. epidermidis-related endocarditis

Designing a Thoracic Compression and Posture Correction Device for Brass Musicians with Pharyngoceles: A Teaching Opportunity

Brass musicians exert high pressures throughout their bodies when playing, and overtime they can establish pharyngoceles. These are balloon-like protrusions that project through the wall of the pharynx and can over-stimulate the Vagus nerve. When this nerve is stressed, the brass musician can develop extreme pain, nausea and psychological distress. This condition was explored as a studio topic, for a senior level Product Design class. Students were tasked to innovate products for practice, performance or recovery, in an attempt to reduce the symptoms caused by the pharyngoceles

Implementation of an Automatic, \u3cem\u3ea Posteriori\u3c/em\u3e, Hierarchical Classification System

This paper describes a total system which provides the capability to semi-automatically index and classify any given file of information. The semi-automatic indexing method assigns key terms to each document in the file . These key terms may be modified, (i.e., added, deleted, or changed) by the user. The indexed documents are then assigned to categories by an automatic classification algorithm. The classification assignments are a posteriori. Classification dictionaries are also produced which can be used as an aid in browsing through the data base and in retrievals from the data base. Samples are given of the results obtained while indexing and classifying an experimental data base containing the texts of 1669 radio messages

14C contamination testing in natural abundance laboratories: a new preparation method using wet chemical oxidation and some experiences

Substances enriched with radiocarbon can easily contaminate samples and laboratories used for natural abundance measurements. We have developed a new method using wet chemical oxidation for swabbing laboratories and equipment to test for 14C contamination. Here, we report the findings of 18 months’ work and more than 800 tests covering studies at multiple locations. Evidence of past and current use of enriched 14C was found at all but one location and a program of testing and communication was used to mitigate its effects. Remediation was attempted with mixed success and depended on the complexity and level of the contamination. We describe four cases from different situations

Carbon in the Deep Biosphere: Forms, Fates, and Biogeochemical Cycling

Building on the synthesis of carbon reservoirs in Earth\u27s subsurface, this chapter focuses on the forms, cycling, and fate of the carbon supporting microbial life in the terrestrial and marine subsurface. As the subsurface is estimated to host a vast reservoir of life on Earth, identifying the carbon compounds that life uses for energy and growth is key to understanding ecosystem functioning in the past and at present, and also for extrapolating these findings to the search for life in the universe. This chapter highlights advances in quantifying small carbon compounds, measuring rates of carbon turnover, and the fate of carbon in the deep biosphere

Carbon in the Deep Biosphere: Forms, Fates, and Biogeochemical Cycling

Building on the synthesis of carbon reservoirs in Earth\u27s subsurface, this chapter focuses on the forms, cycling, and fate of the carbon supporting microbial life in the terrestrial and marine subsurface. As the subsurface is estimated to host a vast reservoir of life on Earth, identifying the carbon compounds that life uses for energy and growth is key to understanding ecosystem functioning in the past and at present, and also for extrapolating these findings to the search for life in the universe. This chapter highlights advances in quantifying small carbon compounds, measuring rates of carbon turnover, and the fate of carbon in the deep biosphere