Do green and golden bell frogs Litoria aurea occupy habitats with fungicidal Do green and golden bell frogs Litoria aurea occupy habitats with fungicidal properties? properties? Abstract AbstractThe Green and Golden Bell frog Utoria aurea is in major decline in Australia, where its distribution is now confined mainly to the east coast of New South Wales (NSW). Infection by the newly emerged amphibian fungal pathogen Batrachochytrium dendrobatidis has been identified as one of the main threats affecting L aureo. Surprisingly, some of the sites in NSW sustaining the largest populations of this species are industrial and urban habitats that are often disturbed and polluted, which could protect L aurea from chytrid infection if pollution had fungicidal capacity The aim of this study was to characterise the trace metal concentration of several L aurea breeding sites in the Sydney and Illawarra regions of NSW and to evaluate the fungicidal efficacy of the main trace metals identified. Selected L aureo sites were sampled throughout the breeding season (September to February) to establish the concentration of trace metals in both surface sediment and waters. Physico-chemical parameters including pH and salinity were also measured. Of the trace metals Identified, copper and zinc were consistently elevated across sites. Over 50% of sites exceeded the National Sediment Quality Guideline for both copper and zinc concentration, and over 90% of sites exceeded the National Water Quality Guideline for these metals. Consequently, we evaluated their effect on the grov/th and survival of a laboratory culture of ß. deridrobatidis.These tests were performed in media containing dissolved metal concentrations of 0.02 -0.65 mgL' Cu and 0.24 -5.0 mgL' Zn. Growth rates were inferred by total fungal density in liquid culture (based on spectral absorbance measurements), final dry weight, and the density of zoospores in fungal cultures grown for 28 days. Both copper and zinc were found to reduce the grov/th and proliferation of ß. dendrobatidis, but in a non-linear manner.This suggests that L aurea may be gaining some protection from ß. dendrobatidis infection at several of the sites examined.

The first Australian isolate of Salmonella enterica serovar Paratyphi B D-tartrate-utilizing (dT ؉ ) that is resistant to ampicillin, chloramphenicol, florfenicol, streptomycin, spectinomycin, sulfonamides, and tetracycline (ApCmFlSmSpSuTc) and contains SGI1 was isolated from a patient with gastroenteritis in early 1995. This is the earliest reported isolation globally. The incidence of infections caused by these SGI1-containing multiply antibiotic-resistant S. enterica serovar Paratyphi B dT ؉ strains increased during the next few years and occurred sporadically in all states of Australia. Several molecular criteria were used to show that the early isolates are very closely related to one another and to strains isolated during the following few years and in 2000 and 2003 from home aquariums and their owners. Early isolates from travelers returning from Indonesia shared the same features. Thus, they appear to represent a true clone arising from a single cell that acquired SGI1. Some minor differences in the resistance profiles and molecular profiles also were observed, indicating the ongoing evolution of the clone, and phage type differences were common, indicating that this is not a useful epidemiological marker over time. Three isolates from 1995, 1998, and 1999 contained a complete sul1 gene but were susceptible to sulfamethoxazole due to a point mutation that creates a premature termination codon. This SGI1 type was designated SGI1-R. The loss of resistance genes also was examined. When strains were grown for many generations in the absence of antibiotic selection, the loss of SGI1 was not detected. However, variants SGI1-C (resistance profile SmSpSu) and SGI1-B (resistant to ApSu), which had lost part of the integron, arose spontaneously, presumably via homologous recombination between duplications in the In104 complex integron.SGI1 was first identified in Salmonella enterica serovar Typhimurium DT104 strains with the ampicillin, chloramphenicol, florfenicol, streptomycin, spectinomycin, sulfonamides, and tetracycline (ApCmFlSmSpSuTc) resistance phenotype (4), and SGI1, or variants of it with different resistance phenotypes and resistance genes, have since been found in many Salmonella serotypes (10,18,19,24,33) and also in Proteus mirabilis (2, 5). SGI1 is an integrating element that can move into new hosts by transduction (31) or via mobilization by an IncA/C plasmid (12), and it establishes itself by integrating into the host chromosome at the end of the thdF gene. However, these events likely are quite rare, and it is possible that all of the SGI1-containing strains of any particular serovar arose from a single cell that acquired the SGI1 genomic island and then expanded in an antibiotic-selective environment and subsequently spread around the globe. A single-cell origin for the widespread multiply antibiotic-resistant S. enterica serovar Typhimurium DT104 clone that contains SGI1 is supported by the finding that the earliest DT104 strains of this type isolated in the United States are identical to thos...

IncA/C plasmids carrying an unusual cassette configuration in a class 1 integron and five further shared resistance genes, aacC4, aphA1, hph, sul2, and tetA(D) were found in Salmonella enterica serovars Senftenberg and Ohio. A deletion formed using a short region of homology in the 5 conserved segment and the orfF cassette created an array with only part of orfF followed by the aadA2 cassette. The IncA/C plasmids were not recoverable by conjugation, but additional conjugative resistance plasmids were present in some strains.

The survival of an isolate of Hyphochytrium catenoides collected from soil in the Blue Mountains in eastern New South Wales, Australia, was tested under extreme conditions in the laboratory. This isolate recovered growth after being subjected to drying on filter paper, to heat while desiccated, to hypersalinity, to strict anaerobic conditions, to freezing temperatures, and to a short period in solutions at pH 2.8-11.2. The capacity to survive under these conditions in the laboratory suggests adaptation to fluctuating conditions in the soil. The partial DNA sequence of the 28S ribosomal RNA gene in the isolate from New South Wales was 98% similar to that in an isolate from Arizona with a similar morphology.