Expanding the Complex with the Addition of Two Novel Species: sp. nov. and sp. nov.

Distinct strains were isolated from soil samples collected in tropical northern Australia (Northern Territory and the Torres Strait Islands, Queensland). Phylogenetic analysis of 16S rRNA and whole genome sequences revealed these strains were distinct from previously described species and assigned them to two novel clades within the B. pseudomallei complex (Bpc).

Melioidosis in Papua New Guinea and Oceania.

Melioidosis has only been sporadically reported throughout Melanesia and the Pacific region since the first report from Guam in 1946; therefore, its contribution to the disease burden in this region is largely unknown. However, the outcome of a small number of active surveillance programs, serological surveys, and presumptive imported cases identified elsewhere provide an insight into its epidemiology and potential significance throughout the region. Both clinical cases and environmental reservoirs have been described from the rural district of Balimo in the Western Province of Papua New Guinea and from the Northern Province of New Caledonia.

Probing the pharmacokinetics of cucurbit[7, 8 and 10]uril: and a dinuclear ruthenium antimicrobial complex encapsulated in cucurbit[10]uril.

The relatively non-toxic family of cucurbit[n]uril, Q[n], have shown considerable potential in vitro as drug delivery agents, with only a few examples of pharmacokinetic (PK) studies for drug⊂Q[n]. Drug-free Q[n] PK studies are the next step in determining the pharmacological applicability in their drug delivery potential. The results for the first PK and bio-distribution of drug-free C-Q[7] are described for administration via intravenous (i.

Oligonuclear polypyridylruthenium(II) complexes: selectivity between bacteria and eukaryotic cells.

Objectives: The objectives of this study were to: (i) determine the in vitro activities of a series of di-, tri- and tetra-nuclear ruthenium complexes (Rubbn, Rubbn-tri and Rubbn-tetra) against a range of Gram-positive and -negative bacteria and compare the antimicrobial activities with the corresponding toxicities against eukaryotic cells; and (ii) compare MIC values with achievable in vivo serum concentrations for the least toxic ruthenium complex.

Methods: The in vitro activities were determined by MIC assays and time-kill curve experiments, while the toxicities of the ruthenium complexes were determined using the Alamar blue cytotoxicity assay. A preliminary pharmacokinetic study was undertaken to determine the Rubb12 serum concentration in mice as a function of time after administration.

Dinuclear ruthenium(ii) complexes containing one inert metal centre and one coordinatively-labile metal centre: syntheses and biological activities.

A series of non-symmetric dinuclear polypyridylruthenium(ii) complexes (Rubbn-Cl) that contain one inert metal centre and one coordinatively-labile metal centre, linked by the bis[4(4'-methyl-2,2'-bipyridyl)]-1,n-alkane ligand ("bbn" for n = 7, 12 and 16), have been synthesised and their potential as antimicrobial agents examined. The minimum inhibitory concentrations (MIC) of the ruthenium(II) complexes were determined against four strains of bacteria--Gram-positive Staphylococcus aureus (S. aureus) and methicillin-resistant S.

Burkholderia pseudomallei is frequently detected in groundwater that discharges to major watercourses in northern Australia.

Burkholderia pseudomallei is the environmental bacterium that causes the serious disease melioidosis. Recently, a high prevalence of viable B. pseudomallei was reported from natural groundwater seeps around Castle Hill, a clinical focus of melioidosis in Townsville, Australia.

Environmental Attributes Influencing the Distribution of Burkholderia pseudomallei in Northern Australia.

Factors responsible for the spatial and temporal clustering of Burkholderia pseudomallei in the environment remain to be elucidated. Whilst laboratory based experiments have been performed to analyse survival of the organism in various soil types, such approaches are strongly influenced by alterations to the soil micro ecology during soil sanitisation and translocation. During the monsoonal season in Townsville, Australia, B.

Mononuclear Polypyridylruthenium(II) Complexes with High Membrane Permeability in Gram-Negative Bacteria-in particular Pseudomonas aeruginosa.

Ruthenium(II) complexes containing the tetradentate ligand bis[4(4'-methyl-2,2'-bipyridyl)]-1,n-alkane ("bbn "; n=10 and 12) have been synthesised and their geometric isomers separated. All [Ru(phen)(bbn )](2+) (phen=1,10-phenanthroline) complexes exhibited excellent activity against Gram-positive bacteria, but only the cis-α-[Ru(phen)(bb12 )](2+) species showed good activity against Gram-negative species. In particular, the cis-α-[Ru(phen)(bb12 )](2+) complex was two to four times more active than the cis-β-[Ru(phen)(bb12 )](2+) complex against the Gram-negative strains.

Seroepidemiology of melioidosis in children from a remote region of Papua New Guinea.

Background: The Balimo region in Papua New Guinea has previously been identified as melioidosis-endemic with a predilection for children. Where health resources are scarce, seroepidemiology can be used to assess exposure to Burkholderia pseudomallei and therefore risk of acquiring melioidosis.

Methods: Logistic regression was used to determine associations between indirect haemagglutination assay (IHA) seroreactivity with environmental and demographic/cultural factors to aid in determining risk factors associated with exposure to B.

Tri- and tetra-nuclear polypyridyl ruthenium(II) complexes as antimicrobial agents.

A series of inert tri- and tetra-nuclear polypyridylruthenium(II) complexes that are linked by the bis[4(4'-methyl-2,2'-bipyridyl)]-1,n-alkane ligand ("bb(n)" for n = 10, 12 and 16) have been synthesised and their potential as antimicrobial agents examined. Due to the modular nature of the synthesis of the oligonuclear complexes, it was possible to make both linear and non-linear tetranuclear ruthenium species. The minimum inhibitory concentrations (MIC) of the ruthenium(II) complexes were determined against four strains of bacteria--Gram positive Staphylococcus aureus (S.

Sago haemolytic disease: towards understanding a novel food-borne toxicosis.

Sago haemolytic disease is a rare but sometimes fatal disease found primarily in the coastal regions of Papua New Guinea and among groups in which sago is a primary source of carbohydrate. It has been known since 1961 and fungi consistently have been suspected of being involved. Investigations carried out on stored sago and samples recovered from poisoning episodes have failed to indicate the consistent presence of mycotoxins.

Dinuclear polypyridylruthenium(II) complexes: flow cytometry studies of their accumulation in bacteria and the effect on the bacterial membrane.

Objectives: To determine the energy dependency of and the contribution of the membrane potential to the cellular accumulation of the dinuclear complexes [{Ru(phen)2}2{μ-bbn}](4+) (Rubbn) and the mononuclear complexes [Ru(Me4phen)3](2+) and [Ru(phen)2(bb7)](2+) in Staphylococcus aureus and Escherichia coli, and to examine their effect on the bacterial membrane.

Methods: The accumulation of the ruthenium complexes in bacteria was determined using flow cytometry at a range of temperatures. The cellular accumulation of the ruthenium complexes was also determined in cells that had been incubated with the metal complexes in the presence or absence of metabolic stimulators or inhibitors and/or commercial dyes to determine the membrane potential or membrane permeability.

Protein binding by dinuclear polypyridyl ruthenium(II) complexes and the effect of cucurbit[10]uril encapsulation.

The effect of human serum on the minimum inhibitory/bactericidal concentrations of the potential antimicrobial agents ΔΔ-[{Ru(phen)2}2(μ-bb(n))](4+) {ΔΔ-Rubb(n); where phen = 1,10-phenanthroline, bb(n) = 1,n-bis[4(4'-methyl-2,2'-bipyridyl)]-alkane for n = 12 and 16} against four strains of bacteria--Gram positive Staphylococcus aureus and methicillin-resistant S. aureus (MRSA), and Gram negative Escherichia coli and Pseudomonas aeruginosa--has been determined. The results demonstrated that the ruthenium(ii) complexes have significantly decreased in vitro activity in serum.

Chlorido-containing ruthenium(II) and iridium(III) complexes as antimicrobial agents.

A series of polypyridyl-ruthenium(II) and -iridium(III) complexes that contain labile chlorido ligands, [{M(tpy)Cl}(2){μ-bb(n)}](2/4+) {Cl-Mbb(n); where M = Ru or Ir; tpy = 2,2':6',2''-terpyridine; and bb(n) = bis[4(4'-methyl-2,2'-bipyridyl)]-1,n-alkane (n = 7, 12 or 16)} have been synthesised and their potential as antimicrobial agents examined. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of the series of metal complexes against four strains of bacteria - Gram positive Staphylococcus aureus (S. aureus) and methicillin-resistant S.

In vitro susceptibility and cellular uptake for a new class of antimicrobial agents: dinuclear ruthenium(II) complexes.

Objectives: To determine the in vitro susceptibility and cellular uptake for a series of dinuclear ruthenium(II) complexes [{Ru(phen)(2)}(2){μ-bb(n)}](4+) (Rubb(n)), and the mononuclear complexes [Ru(Me(4)phen)(3)](2+) and [Ru(phen)(2)(bb(7))](2+) against Staphylococcus aureus, methicillin-resistant S. aureus, Escherichia coli and Pseudomonas aeruginosa.

Methods: The in vitro susceptibility was determined by MIC and MBC assays, and time-kill curve experiments, while the cellular uptake was evaluated by monitoring the fluorescence of the complexes remaining in the supernatant of the cultures after incubation for various periods of time, flow cytometry and confocal microscopy.

Development and validation of Burkholderia pseudomallei-specific real-time PCR assays for clinical, environmental or forensic detection applications.

The bacterium Burkholderia pseudomallei causes melioidosis, a rare but serious illness that can be fatal if untreated or misdiagnosed. Species-specific PCR assays provide a technically simple method for differentiating B. pseudomallei from near-neighbor species.

The antimicrobial activity of inert oligonuclear polypyridylruthenium(II) complexes against pathogenic bacteria, including MRSA.

The minimum inhibitory concentrations (MIC) of a series of synthetic inert polypyridylruthenium(II) complexes against four strains of bacteria--Gram positive Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA), and Gram negative Escherichia coli (E.

Antibiosis of Burkholderia ubonensis againist Burkholderia pseudomallei, the causative agent for melioidosis.

Melioidosis, caused by Burkholderia pseudomallei, is an enigmatic infectious disease that afflicts individuals in many tropical and developing regions. Treatment is hampered by the organism's innate antibiotic resistance and the disease's non-pathognomic presentation. Recently, added attention has been given to this organism due to its classification as a potential biowarfare agent.

Melioidosis--an uncommon but also under-recognized cause of pneumonia in Papua New Guinea.

Melioidosis is being increasingly recognized as an important cause of severe, acute community-acquired pneumonia in various tropical regions. The chronic form of melioidosis can also mimic tuberculosis. Studies have established that, while uncommon in the Port Moresby region, melioidosis is an important cause of pneumonia and sepsis in the Balimo region of Western Province.

Is Penicillium citrinum implicated in sago hemolytic disease?

Sago hemolytic disease (SHD) is an acute hemolytic syndrome affecting rural Papua New Guineans who depend on the starch of Metroxylon sagu as a staple carbohydrate. It is a suspected mycotoxicosis associated with fungal succession in stored and perhaps poorly fermented sago. Despite a mortality rate of approximately 25%, little is know about the disease.

Haemolytic fungi isolated from sago starch in Papua New Guinea.

Sago haemolytic disease (SHD) is a rare but often fatal illness linked to consumption of stale sago starch in Papua New Guinea. Although the aetiology of SHD remains unknown, mycotoxins are suspected. This study investigated whether fungi isolated from Papua New Guinean sago starch were haemolytic.