Initial Effects of Deforestation on Herbaceous Species Composition in Grassy Woodlands of the Northern Tablelands, NSW Australia

Limited information on the initial effects of clearing and thinning on herbaceous vegetation of grassy temperate eucalyptus forests exists. The aim of this investigation is to study the initial changes in species composition following clearing and thinning. A deforestation experiment was established where clearing, thinning of 50% of canopy cover and control treatments were established. In the open-forests, patterns in herbaceous species composition were strongly influenced by the presence of trees, with weeping wheat grass (Microlaena stipoides) dominant, whereas wiregrass (Aristida ramosa) dominated interspaces and canopy gaps. Immediately following clearing, significant changes in the herbaceous species composition were observed, with 26 new species recorded. The original vegetation pattern was lost, being replaced by Cyperaceae and Juncaceae, and a large number of invasive ruderal species. A state and transition model that describes the changes in composition is presented

Development of a Grazing Land Management Education Program for Northern Australia’s Grasslands and Grassy Woodlands

Recognition of the potential to enhance grazing land management to meet the goal of sustainable beef production has been increasing over the past decade. Recognition of the relationship between poor land management and negative off-site environmental impacts, such as soil erosion and a decline in the condition of rivers and adjacent near shore coastal areas from sediment transport, has increased also. This concern has matured somewhat to include the critical link between land condition and production, and the threat to sustainable carrying capacity that comes from declining land condition. Concurrently, interest has increased in optimising the use of pasture, e.g. through the development of infrastructure (watering points, fencing), through more pro-active management e.g. alternative grazing systems, spelling of pastures, and through pasture development. In fact, it can be argued that achieving production goals while improving and maintaining the health of the land has become the major on-property issue for northern Australian graziers

Safety Assessment of the Oral Cavity Probiotic Streptococcus salivarius K12

Streptococcus salivarius is a prominent member of the oral microbiota and has excellent potential for use as a probiotic targeting the oral cavity. In this report we document safety data relating to S. salivarius K12, including assessment of its antibiogram, metabolic profiles, and virulence determinants, and we examine the microbial composition of saliva following the dosing of subjects with K12

Non-Culture-Based Analysis of Bacterial Populations from Patients with Chronic Rhinosinusitis

Middle meatus aspirates from patients with chronic rhinosinusitis were analyzed by bacterial culture, denaturing gradient gel electrophoresis (DGGE), and antibiotic sensitivity techniques. DGGE detected a greater bacterial diversity than culture methods. Although resistance to antibiotics was low, there was evidence of changes in the composition of the bacterial microbiota over time, and the presence of noncultured bacteria was demonstrated

Modelling the Cost Effectiveness of Multiple Sclerosis Therapies Studies Group

Modelling the Cost Effectiveness of Multiple Sclerosis Therapies Studies Grou

Effects of ciprofloxacin, norfloxacin, and ofloxacin on in vitro adhesion and survival of Pseudomonas aeruginosa AK1 on urinary catheters

Streptococcus salivarius strains commonly produce bacteriocins as putative anticompetitor or signalling molecules. Here we report that bacteriocin production by the oral probiotic strain S. salivarius K12 is encoded by a large (ca. 190 kb) plasmid. Oral cavity transmission of the plasmid from strain K12 to a plasmid-negative variant of this bacterium was demonstrated in two subjects. Tests of additional S. salivarius strains showed large (up to ca. 220 kb) plasmids present in bacteriocin-producing isolates. Various combinations (up to 3 per plasmid) of loci encoding the known streptococcal lantibiotics salivaricin A, salivaricin B, streptin and SA-FF22 were localised to these plasmids. Since all bacteriocin-producing strains of S. salivarius tested to date appear to harbour plasmids, it appears that they may function as mobile repositories for bacteriocin loci, especially those of the lantibiotic class. © Springer Science+Business Media B.V. 2006

Production of the Lantibiotic Salivaricin A and Its Variants by Oral Streptococci and Use of a Specific Induction Assay To Detect Their Presence in Human Saliva

Salivaricin A (SalA), the first Streptococcus salivarius lantibiotic to be characterized, appears to be inhibitory to most Streptococcus pyogenes strains. A variant of the SalA structural gene (salA1) is present in more than 90% of S. pyogenes strains, but only strains of M serotype 4 and T pattern 4 produce the biologically active peptide. The present study identifies four additional variants (salA2 to salA5) of the SalA structural gene and demonstrates that each of the corresponding inhibitory peptides (SalA2 to SalA5) is produced in vitro. These variants appear to be similar to SalA and SalA1 in their inhibitory activity against Micrococcus luteus and in their ability to act as inducers of SalA production. It had previously been shown that S. pyogenes strain SF370 had a deletion (of approximately 2.5 kb) in the salM and salT genes of the salA1 locus. In the present study, several additional characteristic deletions within the salA1 loci were identified. S. pyogenes strains of the same M serotype all share the same salA1 locus structure. Since S. salivarius is a predominant member of the normal oral flora of healthy humans, strains producing anti-S. pyogenes lantibiotics, such as SalA, may have excellent potential for use as oral probiotics. In the present study, we have used a highly specific SalA induction system to directly detect the presence of SalA in the saliva of humans who either naturally harbor populations of SalA-producing S. salivarius or who have been colonized with the SalA2-producing probiotic S. salivarius K12