28 research outputs found
Development of a laboratory system and 2D routing analysis to determine solute mixing within aquatic vegetation
A laser induced fluorometry (LIF) system was developed to quantify mixing within spatially variable aquatic vegetation. A comparison is made between intrusive fluorometry techniques and the application of LIF, to quantify mixing in real vegetation in the laboratory setting. LIF provides greater spatial resolution when compared to point fluorometry. Furthermore, LIF is non-intrusive. A two-dimensional routing procedure is used to calculate the longitudinal and transverse velocities and mixing coefficients from a single pulse injection of tracer within a vegetation patch
A Field Guide to Pandemic, Epidemic and Sporadic Clones of Methicillin-Resistant Staphylococcus aureus
In recent years, methicillin-resistant Staphylococcus aureus
(MRSA) have become a truly global challenge. In addition to the long-known
healthcare-associated clones, novel strains have also emerged outside of the
hospital settings, in the community as well as in livestock. The emergence and
spread of virulent clones expressing Panton-Valentine leukocidin (PVL) is an
additional cause for concern. In order to provide an overview of pandemic,
epidemic and sporadic strains, more than 3,000 clinical and veterinary isolates
of MRSA mainly from Germany, the United Kingdom, Ireland, France, Malta, Abu
Dhabi, Hong Kong, Australia, Trinidad & Tobago as well as some reference
strains from the United States have been genotyped by DNA microarray analysis.
This technique allowed the assignment of the MRSA isolates to 34 distinct
lineages which can be clearly defined based on non-mobile genes. The results
were in accordance with data from multilocus sequence typing. More than 100
different strains were distinguished based on affiliation to these lineages,
SCCmec type and the presence or absence of PVL. These
strains are described here mainly with regard to clinically relevant
antimicrobial resistance- and virulence-associated markers, but also in relation
to epidemiology and geographic distribution. The findings of the study show a
high level of biodiversity among MRSA, especially among strains harbouring
SCCmec IV and V elements. The data also indicate a high
rate of genetic recombination in MRSA involving SCC elements, bacteriophages or
other mobile genetic elements and large-scale chromosomal replacements
A Field Guide to Pandemic, Epidemic and Sporadic Clones of Methicillin-Resistant Staphylococcus aureus
In recent years, methicillin-resistant Staphylococcus aureus
(MRSA) have become a truly global challenge. In addition to the long-known
healthcare-associated clones, novel strains have also emerged outside of the
hospital settings, in the community as well as in livestock. The emergence and
spread of virulent clones expressing Panton-Valentine leukocidin (PVL) is an
additional cause for concern. In order to provide an overview of pandemic,
epidemic and sporadic strains, more than 3,000 clinical and veterinary isolates
of MRSA mainly from Germany, the United Kingdom, Ireland, France, Malta, Abu
Dhabi, Hong Kong, Australia, Trinidad & Tobago as well as some reference
strains from the United States have been genotyped by DNA microarray analysis.
This technique allowed the assignment of the MRSA isolates to 34 distinct
lineages which can be clearly defined based on non-mobile genes. The results
were in accordance with data from multilocus sequence typing. More than 100
different strains were distinguished based on affiliation to these lineages,
SCCmec type and the presence or absence of PVL. These
strains are described here mainly with regard to clinically relevant
antimicrobial resistance- and virulence-associated markers, but also in relation
to epidemiology and geographic distribution. The findings of the study show a
high level of biodiversity among MRSA, especially among strains harbouring
SCCmec IV and V elements. The data also indicate a high
rate of genetic recombination in MRSA involving SCC elements, bacteriophages or
other mobile genetic elements and large-scale chromosomal replacements