A case of imported Leishmania infantum cutaneous leishmaniasis; an unusual presentation occurring 19 years after travel

BACKGROUND: Leishmania infantum is a flagellated protozoan parasite that is able to parasitize blood and tissue. Leishmania species cause a spectrum of clinical disease with cutaneous, visceral or mucosal involvement. L. infantum is recognised as a cause of visceral leishmaniasis (VL) and is less commonly reported as a cause of cutaneous leishmaniasis (CL) from countries around the Mediterranean basin. This is the first report of imported L. infantum CL to Australia and is remarkable for a 19 year period between the patient's exposure to an endemic region, and the manifestation of symptoms. CASE PRESENTATION: A 76 year old Italian-born man presented to our institution with a non-healing lesion over his upper lip, abutting his nasal mucosa. The patient had travelled to Italy, an endemic area for L. infantum 19 years earlier but had resided in Australia, a non-endemic area since. Histopathology performed on a biopsy of the lesion demonstrated findings consistent with CL. A species specific polymerase chain reaction (PCR) performed on the tissue detected L. infantum. The patient had complete clinical recovery following treatment with Liposomal amphotericin B at a dose of 3 mg/kg for five days followed by a subsequent 3 mg/kg dose at day ten. CONCLUSIONS: L. infantum should be recognised as a cause of imported CL in returned travellers from the Mediterranean. In this case, the incubation period for L. infantum CL was at least 19 years. This case adds to the described spectrum of clinical presentations of leishmaniasis and supports the theory of parasite persistence underlying natural immunity and recurrence of disease. Clinicians should consider L. infantum CL in the differential diagnosis of a non-healing skin lesion in any patient who reports travel to the Mediterranean, even when travel occurred several years before clinical presentation

Invasive Amebiasis in Men Who Have Sex with Men, Australia

Entamoeba histolytica is a pathogenic ameba that has recently been recognized as an emerging pathogen in men who have sex with men (MSM) in Asia-Pacific countries where it is not endemic, i.e., Japan, Taiwan, and Republic of Korea. We report locally acquired invasive amebiasis in Sydney, Australia, exclusively in MSM

Epidemiology and geographical distribution of enteric protozoan infections in Sydney, Australia

Background. Enteric protozoa are associated with diarrhoeal illnesses in humans; however there are no recent studies on their epidemiology and geographical distribution in Australia. This study describes the epidemiology of enteric protozoa in the state of New South Wales and incorporates spatial analysis to describe their distribution. Design and methods. Laboratory and clinical records from four public hospitals in Sydney for 910 patients, who tested positive for enteric protozoa over the period January 2007-December 2010, were identified, examined and analysed. We selected 580 cases which had residence post code data available, enabling us to examine the geographic distribution of patients, and reviewed the clinical data of 252 patients to examine possible links between protozoa, demographic and clinical features. Results. Frequently detected protozoa were Blastocystis spp. (57%), Giardia intestinalis (27%) and Dientamoeba fragilis (12%). The age distribution showed that the prevalence of protozoa decreased with age up to 24 years but increasing with age from 25 years onwards. The geographic provenance of the patients indicates that the majority of cases of Blastocystis (53.1%) are clustered in and around the Sydney City Business District, while pockets of giardiasis were identified in regional/rural areas. The distribution of cases suggests higher risk of protozoan infection may exist for some communities. Conclusions. These findings provide useful information for policy makers to design and tailor interventions to target high risk communities. Follow-up investigation into the risk factors for giardiasis in regional/rural area is needed

Candida dubliniensis Meningitis as Delayed Sequela of Treated C. dubliniensis Fungemia

We present a case of Candida dubliniensis meningitis that developed 2 months after apparently successful treatment of an episode of C. dubliniensis candidemia in a heart-lung transplant recipient in Australia. This case highlights the importance of follow-up in patients with candidemia or disseminated infection, especially in immunosuppressed patients

A new subspecies of Trypanosoma cyclops found in the Australian terrestrial leech Chtonobdella bilineata

Previously, it was suggested that haemadipsid leeches represent an important vector of trypanosomes amongst native animals in Australia. Consequently, Chtonobdella bilineata leeches were investigated for the presence of trypanosome species by polymerase chain reaction (PCR), DNA sequencing and in vitro isolation. Phylogenetic analysis ensued to further define the populations present. PCR targeting the 28S rDNA demonstrated that over 95% of C. bilineata contained trypanosomes; diversity profiling by deep amplicon sequencing of 18S rDNA indicated the presence of four different clusters related to the Trypanosoma (Megatrypanum) theileri. Novy-MacNeal-Nicolle slopes with liquid overlay were used to isolate trypanosomes into culture that proved similar in morphology to Trypanosoma cyclops in that they contained a large numbers of acidocalcisomes. Phylogeny of 18S rDNA/GAPDH/ND5 DNA sequences from primary cultures and subclones showed the trypanosomes were monophyletic, with T. cyclops as a sister group. Blood-meal analysis of leeches showed that leeches primarily contained blood from swamp wallaby (Wallabia bicolour), human (Homo sapiens) or horse (Equus sp.). The leech C. bilineata is a host for at least five lineages of Trypanosoma sp. and these are monophyletic with T. cyclops; we propose Trypanosoma cyclops australiensis as a subspecies of T. cyclops based on genetic similarity and biogeography considerations

Effect of ultrapure lipopolysaccharides derived from diverse bacterial species on the modulation of platelet activation

Platelets are small circulating blood cells that play essential roles in the maintenance of haemostasis via blood clotting. However, they also play critical roles in the regulation of innate immune responses. Inflammatory receptors, specifically Toll-like receptor (TLR)-4, have been reported to modify platelet reactivity. A plethora of studies have reported controversial functions of TLR4 in the modulation of platelet function using various chemotypes and preparations of its ligand, lipopolysaccharide (LPS). The method of preparation of LPS may explain these discrepancies however this is not fully understood. Hence, to determine the impact of LPS on platelet activation, we used ultrapure preparations of LPS from Escherichia coli (LPSEC), Salmonella minnesota (LPSSM), and Rhodobacter sphaeroides (LPSRS) and examined their actions under diverse experimental conditions in human platelets. LPSEC did not affect platelet activation markers such as inside-out signalling to integrin IIb3 or P-selectin exposure upon agonist-induced activation in platelet-rich plasma or whole blood whereas LPSSM and LPSRS inhibited platelet activation under specific conditions at supraphysiological concentrations. Overall, our data demonstrate that platelet activation is not largely influenced by any of the ultrapure LPS chemotypes used in this study on their own except under certain conditions

Biocompatibility and Bone Formation of Flexible, Cotton Wool-like PLGA/Calcium Phosphate Nanocomposites in Sheep

BACKGROUND: The purpose of this preliminary study was to assess the in vivo performance of synthetic, cotton wool-like nanocomposites consisting of a biodegradable poly(lactide-co-glycolide) fibrous matrix and containing either calcium phosphate nanoparticles (PLGA/CaP 60:40) or silver doped CaP nanoparticles (PLGA/Ag-CaP 60:40). Besides its extraordinary in vitro bioactivity the latter biomaterial (0.4 wt% total silver concentration) provides additional antimicrobial properties for treating bone defects exposed to microorganisms. MATERIALS AND METHODS: Both flexible artificial bone substitutes were implanted into totally 16 epiphyseal and metaphyseal drill hole defects of long bone in sheep and followed for 8 weeks. Histological and histomorphological analyses were conducted to evaluate the biocompatibility and bone formation applying a score system. The influence of silver on the in vivo performance was further investigated. RESULTS: Semi-quantitative evaluation of histology sections showed for both implant materials an excellent biocompatibility and bone healing with no resorption in the adjacent bone. No signs of inflammation were detectable, either macroscopically or microscopically, as was evident in 5 µm plastic sections by the minimal amount of inflammatory cells. The fibrous biomaterials enabled bone formation directly in the centre of the former defect. The area fraction of new bone formation as determined histomorphometrically after 8 weeks implantation was very similar with 20.5 ± 11.2 % and 22.5 ± 9.2 % for PLGA/CaP and PLGA/Ag-CaP, respectively. CONCLUSIONS: The cotton wool-like bone substitute material is easily applicable, biocompatible and might be beneficial in minimal invasive surgery for treating bone defects

RNA chaperoning and intrinsic disorder in the core proteins of Flaviviridae

RNA chaperone proteins are essential partners of RNA in living organisms and viruses. They are thought to assist in the correct folding and structural rearrangements of RNA molecules by resolving misfolded RNA species in an ATP-independent manner. RNA chaperoning is probably an entropy-driven process, mediated by the coupled binding and folding of intrinsically disordered protein regions and the kinetically trapped RNA. Previously, we have shown that the core protein of hepatitis C virus (HCV) is a potent RNA chaperone that can drive profound structural modifications of HCV RNA in vitro. We now examined the RNA chaperone activity and the disordered nature of core proteins from different Flaviviridae genera, namely that of HCV, GBV-B (GB virus B), WNV (West Nile virus) and BVDV (bovine viral diarrhoea virus). Despite low-sequence similarities, all four proteins demonstrated general nucleic acid annealing and RNA chaperone activities. Furthermore, heat resistance of core proteins, as well as far-UV circular dichroism spectroscopy suggested that a well-defined 3D protein structure is not necessary for core-induced RNA structural rearrangements. These data provide evidence that RNA chaperoning—possibly mediated by intrinsically disordered protein segments—is conserved in Flaviviridae core proteins. Thus, besides nucleocapsid formation, core proteins may function in RNA structural rearrangements taking place during virus replication