551 research outputs found
SME adaptive capacity in response to environmental requirements: understanding it as a complex adaptive system
The pressure on Small and Medium sized Enterprises (SMEs) in emerging economies to adapt their production and management to meet global industrial environmental standards is enormous. These pressures come from both the international supply chain and the government’s environmental legislation. Yet, an effective way to help SMEs adapt to these challenges in emerging economies is not reported. Little is available about environmental adaptation process at SMEs in developing countries. This paper attempts to address this gap in knowledge. It uses the theory of Complex Adaptive Systems to understand the complex nature of environmental adaptation at SMEs, and more importantly, it outlines an agenda for further research to identify key success factors for the environmental adaptation process at SMEs based on the key components of such a system
Electrospun Zein/PCL Fibrous Matrices Release Tetracycline in a Controlled Manner, Killing Staphylococcus aureus Both in Biofilms and Ex Vivo on Pig Skin, and are Compatible with Human Skin Cells
PURPOSE: To investigate the destruction of clinically-relevant bacteria within biofilms via the sustained release of the antibiotic tetracycline from zein-based electrospun polymeric fibrous matrices and to demonstrate the compatibility of such wound dressing matrices with human skin cells. METHODS: Zein/PCL triple layered fibrous dressings with entrapped tetracycline were electrospun. The successful entrapment of tetracycline in these dressings was validated. The successful release of bioactive tetracycline, the destruction of preformed biofilms, and the viability of fibroblast (FEK4) cells were investigated. RESULTS: The sustained release of tetracycline from these matrices led to the efficient destruction of preformed biofilms from Staphylococcus aureus MRSA252 in vitro, and of MRSA252 and ATCC 25923 bacteria in an ex vivo pig skin model using 1 × 1 cm square matrices containing tetracycline (30 μg). Human FEK4 cells grew normally in the presence of these matrices. CONCLUSIONS: The ability of the zein-based matrices to destroy bacteria within increasingly complex in vitro biofilm models was clearly established. An ex vivo pig skin assay showed that these matrices, with entrapped tetracycline, efficiently kill bacteria and this, combined with their compatibility with a human skin cell line suggest these matrices are well suited for applications in wound healing and infection control
Commonwealth Marine Reserves Review: Report of the Expert Scientific Panel
The report provides a scientific basis for the declaration and management of the Australian Marine Reserve Syste
Transmission dynamics of Tasmanian devil facial tumor disease may lead to disease-induced extinction
Most pathogens threatening to cause extinction of a host species are maintained on one or more reservoir hosts, in addition to the species that is threatened by disease. Further, most conventional host–pathogen theory assumes that transmission is related to host density, and therefore a pathogen should become extinct before its sole host. Tasmanian devil facial tumor disease is a recently emerged infectious cancer that has led to massive population declines and grave concerns for the future persistence of this largest surviving marsupial carnivore. Here we report the results of mark–recapture studies at six sites and use these data to estimate epidemiological parameters critical to both accurately assessing the risk of extinction from this disease and effectively managing this disease threat. Three sites were monitored from before or close to the time of disease arrival, and at three others disease was well established when trapping began, in one site for at least 10 years. We found no evidence for sex-specific differences in disease prevalence and little evidence of consistent seasonal variation in the force of infection. At all sites, the disease was maintained at high levels of prevalence (>50% in 2–3-year-old animals), despite causing major population declines. We also provide the first estimates of the basic reproductive rate R0 for this disease. Using a simple age-structured deterministic model, we show that our results are not consistent with transmission being proportional to the density of infected hosts but are consistent with frequency-dependent transmission. This conclusion is further supported by the observation that local disease prevalence in 2–3-year-olds still exceeds 50% at a site where population density has been reduced by up to 90% in the past 12 years. These findings lend considerable weight to concerns that this host-specific pathogen will cause the extinction of the Tasmanian devil. Our study highlights the importance of rapidly implementing monitoring programs to determine how transmission depends on host density and emphasizes the need for ongoing management strategies involving a disease-free “insurance population,” along with ongoing field monitoring programs to confirm whether local population extinction occur
The role of Ureaplasma spp. in the development of non-gonococcal urethritis and infertility among men
Ureaplasma spp. are a genus of bacteria for which two human associated species exist; Ureaplasma urealyticum and Ureaplasma parvum. Their definition as a pathogen in the context of non-gonococcal urethritis and infertility among males remains highly controversial, largely due to historically high isolation rates of these bacteria from the urethra of seemingly healthy men. This review summarises the emerging evidence suggesting a true pathogenic role of these bacteria under specific conditions, which we term as risk factors. We examine the historical, clinical and experimental studies which support a causal role for Ureaplasma spp in the development of NGU as well as some of the proposed mechanisms behind the association of Ureaplasma spp. and the development of infertility. Finally, we discuss the potential for developing a case-by-case risk-based approach towards the management of men who present with seemingly idiopathic NGU, but are positive for Ureaplasma spp
Different expression of [béta] subunits of the KCa1.1 channel by invasive and non-invasive human fibroblast-like synoviocytes
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Antimicrobial activity of enacyloxin IIa and gladiolin against the urogenital pathogens Neisseria gonorrhoeae and Ureaplasma spp
Aims
To determine the antimicrobial activity of enacyloxin IIa and gladiolin against N. gonorrhoeae and Ureaplasma spp.
Methods and Results
The Burkholderia polyketide antibiotics enacyloxin IIa and gladiolin were tested against 14 N. gonorrhoeae and 10 Ureaplasma spp. isolates including multi‐drug resistant N. gonorrhoeae isolates WHO V, WHO X and WHO Z as well as macrolide, tetracycline and ciprofloxacin resistant ureaplasmas. Susceptibility testing of N. gonorrhoeae were carried out by agar dilution, whereas broth micro‐dilution and growth kinetic assays was used for Ureaplasma spp. The MIC range for enacyloxin IIa and gladiolin against N. gonorrhoeae was 0.015 – 0.06 mg/L and 1 ‐ 2 mg/L, respectively. The presence of resistance to front line antibiotics had no effect on MIC values. The MIC range for enacyloxin IIa against Ureaplasma spp. was 4 – 32 mg/L with a clear dose‐dependent effect when observed using a growth kinetic assay. Gladiolin had no antimicrobial activity on Ureaplasma spp. at 32 mg/L and limited impact on growth kinetics.
Conclusions
Enacyloxin IIa and gladiolin antibiotics have antimicrobial activity against a range of antibiotic susceptible and resistant N. gonorrhoeae and Ureaplasma isolates.
Significance and Impact of Study
This study highlights the potential for a new class of antimicrobial against pathogens in which limited antibiotics are available. Development of these compounds warrants further investigation in the face of emerging extensively‐drug resistant strains
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