Characterisation of the efficacy of endodontic medications using a three-dimensional fluorescent tooth model: An ex vivo study

The purpose of this study was to establish a three-dimensional fluorescent tooth model to investigate bacterial viability against intra-canal medicaments across the thickness and surface of root dentine. Dental microbial biofilms (Enterococcus faecalis and Streptococcus mutans) were established on the external root surface and bacterial kill was monitored over time against intra-canal medicament (Ca(OH)2 ) using fluorescent microscopy in conjunction with BacLight SYTO9 and propidium iodide stains. An Olympus digital camera fitted to SZX16 fluorescent microscope captured images of bacterial cells in biofilms on the external root surface. Viability of biofilm was measured by calculating the total pixel area of green (viable bacteria) and red (non-viable bacteria) for each image using ImageJ® software. All data generated were assessed for normality and then analysed using a Mann-Whitney t-test. The viability of S. mutans biofilm following Ca(OH)2 treatment showed a significant decline compared with the untreated group (P = 0.0418). No significant difference was seen for E. faecalis biofilm between the Ca(OH)2 and untreated groups indicating Ca(OH)2 medicament is ineffective against E. faecalis biofilm. This novel three-dimensional fluorescent biofilm model provides a new clinically relevant tool for testing of medicaments against dental biofilms.

First report of Colombian datura virus from Australia.

Colombian datura virus was identified from the ornamental plant Brugmansia sp., showing leaf mosaic symptoms. The nucleotide sequence of the 3 untranslated region and the amino acid sequence of the 3 portion of the coat protein were 100% identical to those from a Hungarian isolate of the virus. This represents the first record of this virus in Australia.

Attributes of clinical role models as described by senior veterinary students in Australia

Role models incite admiration and provide inspiration, contributing to learning as students aspire to emulate their example. The attributes of physician role models for medical trainees are well documented, but they remain largely unexplored in the context of veterinary medical training. The aim of the current study was to describe the attributes that final-year veterinary students (N=213) at the University of Queensland identified when reflecting on their clinical role models. Clinical role model descriptions provided by students were analyzed using concept-mapping software (Leximancer v. 2.25). The most frequent and highly connected concepts used by students when describing their role model(s) included clients, vet, and animal. Role models were described as good communicators who were skilled at managing relationships with clients, patients, and staff. They had exemplary knowledge, skills, and abilities, and they were methodical and conducted well-structured consultations. They were well respected and, in turn, demonstrated respect for clients, colleagues, staff, and students alike. They were also good teachers and able to tailor explanations to suit both clients and students. Findings from this study may serve to assist with faculty development and as a basis for further research in this area.

Human bladder uroepithelial cells synergize with monocytes to promote IL-10 synthesis and other cytokine responses to Uropathogenic Escherichia coli

Urinary tract infections are a major source of morbidity for women and the elderly, with Uropathogenic Escherichia coli (UPEC) being the most prevalent causative pathogen. Studies in recent years have defined a key anti-inflammatory role for Interleukin-10 (IL-10) in urinary tract infection mediated by UPEC and other uropathogens. We investigated the nature of the IL-10-producing interactions between UPEC and host cells by utilising a novel co-culture model that incorporated lymphocytes, mononuclear and uroepithelial cells in histotypic proportions. This co-culture model demonstrated synergistic IL-10 production effects between monocytes and uroepithelial cells following infection with UPEC. Membrane inserts were used to separate the monocyte and uroepithelial cell types during infection and revealed two synergistic IL-10 production effects based on contact-dependent and soluble interactions. Analysis of a comprehensive set of immunologically relevant biomarkers in monocyte-uroepithelial cell co-cultures highlighted that multiple cytokine, chemokine and signalling factors were also produced in a synergistic or antagonistic fashion. These results demonstrate that IL-10 responses to UPEC occur via multiple interactions between several cells types, implying a complex role for infection-related IL-10 during UTI. Development and application of the co-culture model described in this study is thus useful to define the degree of contact dependency of biomarker production to UPEC, and highlights the relevance of histotypic co-cultures in studying complex host-pathogen interactions.

Infection-induced IL-10 and Jak-Stat: A review of the molecular circuitry controlling immune hyperactivity in response to pathogenic microbes

Generation of effective immune responses against pathogenic microbes depends on a fine balance between pro- and anti-inflammatory responses. Interleukin-10 (IL-10) is essential in regulating this balance and has garnered renewed interest recently as a modulator of the response to infection at the JAK-STAT signaling axis of host responses. Here, we examine how IL-10 functions as the “master regulator” of immune responses through JAK-STAT, and provide a perspective from recent insights on bacterial, protozoan, and viral infection model systems. Pattern recognition and subsequent molecular events that drive activation of IL-10-associated JAK-STAT circuitry are reviewed and the implications for microbial pathogenesis are discussed.

Genome-wide mapping of cystitis due to Streptococcus agalactiae and Escherichia coli in mice identifies a unique bladder transcriptome that signifies pathogen-specific antimicrobial defense against urinary tract infection

The most common causes of urinary tract infections (UTIs) are Gram-negative pathogens such as Escherichia coli; however, Gram-positive organisms including Streptococcus agalactiae, or group B streptococcus (GBS), also cause UTI. In GBS infection, UTI progresses to cystitis once the bacteria colonize bladder, but the host responses triggered in the bladder immediately following infection are largely unknown. Here, we used genome-wide expression profiling to map the bladder transcriptome of GBS UTI in mice infected transurethrally with uropathogenic GBS that was cultured from a 35 year-old women with cystitis. RNA from bladders was applied to Affymetrix Gene-1.0ST microarrays; qRT-PCR was used to analyze selected gene responses identified in array datasets. A surprisingly small significant gene list of 172 genes was identified at 24h; this compared to 2507 genes identified in a side-by-side comparison with uropathogenic E. coli (UPEC). No genes exhibited significantly altered expression at 2h in GBS-infected mice according to arrays despite high bladder bacterial loads at this early time point. The absence of a marked early host response to GBS juxtaposed with broad-based bladder responses activated by UPEC at 2h. Bioinformatics analyses including integrative systems-level network mapping revealed multiple activated biological pathways in the GBS cystitis transcriptome that regulate leukocyte activation, inflammation, apoptosis, and cytokine-chemokine biosynthesis. These findings define a novel, minimalistic type of bladder host response triggered by GBS UTI, which comprises collective antimicrobial pathways that differ dramatically from those activated by UPEC. Overall, this study emphasizes the unique nature of bladder immune activation mechanisms triggered by distinct uropathogens.

Clinical Escherichia coli isolates utilize alpha-hemolysin to inhibit in vitro epithelial cytokine production

Uropathogenic Escherichia coli is the primary cause of urinary tract infections, which affects over 60% of women during their lifetime. UPEC exhibits a number of virulence traits that facilitate colonization of the bladder, including inhibition of cytokine production by bladder epithelial cells. The goal of this study was to identify the mechanism of this inhibition. We observed that cytokine suppression was associated with rapid cytotoxicity toward epithelial cells. We found that cytotoxicity, cytokine suppression and alpha-hemolysin production were all tightly linked in clinical isolates. We screened a UPEC fosmid library and identified clones that gained the cytotoxicity and cytokine-suppression phenotypes. Both clones contained fosmids encoding a PAI II(J96)-like domain and expressed the alpha-hemolysin (hlyA) encoded therein. Mutation of the fosmid-encoded hly operon abolished cytotoxicity and cytokine suppression. Similarly, mutation of the chromosomal hlyCABD operon of UPEC isolate F11 also abolished these phenotypes, and they could be restored by introducing the PAI II(J96)-like domain-encoding fosmid. We also examined the role of alpha-hemolysin in cytokine production both in the murine UTI model as well as patient specimens. We conclude that E. coli utilizes alpha-hemolysin to inhibit epithelial cytokine production in vitro. Its contribution to inflammation during infection requires further study.

National screening for barley grain defects

Three defects on barley grain can impact on the price paid to grain growers. Black point (BP), kernel staining (KS) and pre-harvest sprouting (PHS) can result in malting barley being downgraded to feed. Resistance to these defects is the best option, and in this project hundreds of breeding lines grown over three years were screened for these traits. A number of lines exhibited resistance to each defect but very few had resistance to all defects. The results from the screening program have been provided to the Australian barley breeders through the Barley Breeding Australia (BBA) program.

DAQ00104 Sponge and dough bread quality of Australian wheat germplasm

The main grade of wheat targeted for the export sponge and dough (S&D) market is Australian prime hard (APH). By association, protein should be a key parameter relating to S&D quality, specifically loaf volume (LV). Surprisingly, the project revealed a low level of correlation between total protein content and LV. It appears that protein composition may be the key to understanding S&D quality, as the glutenin Glu D1 5+10 subunit contributed to the highest LVs. The current varieties KennedyA and SunzellA, together with several breeding lines, provided a consistently high quality over a number of seasons. These varieties performed as well as, if not better than, North American S&D varieties.

Vadelman (Rubus idaeus) kasvunsäätö proheksadioni-kalsiumin avulla

Vadelman (Rubus idaeus L.) viljelyala on kasvanut Suomessa voimakkaasti viimeisten viiden vuoden aikana. Vuonna 2005 vadelmaa viljeltiin 473 hehtaarilla. Vadelman satoindeksi on alhainen. Sen pääverso on pitkä, mikä hankaloittaa hoitotoimenpiteitä. Kasvin satoisimmat silmut ovat pääverson kärjessä, joten latvontaa ei kannata tehdä. Suomessakin haluttaisiin kehittää vadelman kasvihuonetuotantoa satokauden pidentämiseksi. Kasvihuonetuotannossa vegetatiivisen kasvun säätäminen on vielä tärkeämpää kuin avomaan viljelyssä. Proheksadioni-kalsium (ProCa) on gibberelliinisynteesi-inhibiittori, jonka on havaittu lyhentävän nivelvälejä sekä lisäävän versojen ja lehtien hiilihydraattipitoisuutta mm. omenalla (Malus domestica Borkh.). Tämän Helsingin yliopiston soveltavan biologian laitoksella toteutetun tutkimuksen tarkoituksena oli selvittää, miten ProCa vaikuttaa kahden kesävadelmalajikkeen ensimmäisen vuoden versojen vegetatiiviseen kasvuun ja edelleen sadontuottokykyyn. Tässä pro gradu -työssä tutkittiin ProCa:n vaikutusta kahden kesävadelmalajikkeen vegetatiiviseen kasvuun, satopotentiaaliin sekä versojen ja silmujen hiilihydraattipitoisuuksiin kesällä 2005 ja talvella 2006. Koetaimina oli 120 Tulameen-lajikkeen ja 150 Glen Ample -lajikkeen tainta. Taimet käsiteltiin kesäkuussa ja käsittely uusittiin osalle taimista neljän viikon kuluttua ensimmäisestä käsittelystä. Koekäsittelyitä oli neljä: ProCa 100 ppm, ProCa 200 ppm, ProCa 100 ppm + ProCa 100 ppm ja ProCa 200 ppm + ProCa 200 ppm. Kontrollikäsittelyitä oli kaksi: vesi sekä vesi + vesi. Kesän aikana havainnoitiin pääverson pituuskasvua ja nivelien määrää. Kesän kasvatuskauden päätyttyä Glen Ample -lajikkeen silmujen ja versojen liukoiset hiilihydraatit ja tärkkelys määritettiin entsymaattisesti. Kylmävarastoinnin jälkeen (71 vrk) tammikuussa 2006 taimet siirrettiin hyötöön kasvihuoneeseen. Hyödön aikana havainnoitiin silmujen puhkeamista ja kukintaa. Hyödön päättyessä hanka- ja pääversojen kuivapaino sekä hankaversojen pituus mitattiin. Kesän 2005 aikana ProCa lyhensi uusien nivelvälien pituuksia väliaikaisesti 1 4 viikon kuluttua käsittelystä. Nivelien lukumäärässä ei tapahtunut suuria muutoksia. Tulameen-lajikkeella kasvu kiihtyi käsittelyn vaikutuksen loputtua. Nivelvälien lyhentymisen takia pääverson kokonaispituus jäi kontrolliin verrattuna 35 % lyhyemmäksi Glen Ample -lajikkeella (ProCa 200 + ProCa 200) ja 14 % lyhyemmäksi Tulameen-lajikkeella samalla käsittelyllä. Myös käsittely ProCa 200 vähensi pääverson pituutta 6 % kontrolliin verrattuna Tulameen-lajikkeella. ProCa-käsittely lisäsi versojen ja silmujen hiilihydraattipitoisuuksia, mutta tuloksissa oli paljon hajontaa. Glen Ample -lajikkeella kaksinkertaiset käsittelyt vähensivät puhjenneiden silmujen osuutta 8 15 päivän kuluttua hyödön aloittamisesta 24 29 %, mutta käsittelyiden väliset erot tasoittuivat hyödön loppuun mennessä. Lisäksi kaksinkertaiset ProCa-käsittelyt vähensivät kukkien määrää 29 44 % 33 65 päivää hyödön alusta, mutta erot tasoittuivat hyödön loppuun mennessä. Käsittelyt eivät vaikuttaneet Tulameen-lajikkeen silmujen puhkeamiseen ja kukintaan. Satopotentiaalissa ei ollut eroa ProCa-käsittelyiden välillä kummallakaan lajikkeella. Glen Ample -lajikkeella hankaversojen kokonaismäärä väheni 27 32 % kasveilla, joita oli käsitelty kaksi kertaa ProCa:lla. Hankaversot olivat kuitenkin vastaavasti 29 43 % pidempiä. Tulameen-lajikkeella ProCa 100 -käsittely vähensi hankaversojen määrää 15 %, mutta hankaversojen pituuteen käsittelyillä ei ollut vaikutusta. Käsittelyillä ei ollut vaikutusta hankaversojen nivelvälien pituuteen kummallakaan lajikkeella. Tutkimuksen perusteella kesällä annetulla ProCa-käsittelyllä voidaan lyhentää pääverson pituutta, mutta satopotentiaaliin käsittelyllä ei ole vaikutusta. Käsittelyajankohta on kriittinen, koska kukkasilmujen kehitys näyttäisi häiriintyvän, jos ruiskutus tehdään loppukesällä.

Design and flight testing of a bio-inspired plume tracking algorithm for unmanned serial vehicles

There is an increased interest on the use of UAVs for environmental research such as tracking bush fires, volcanic eruptions, chemical accidents or pollution sources. The aim of this paper is to describe the theory and results of a bio-inspired plume tracking algorithm. A method for generating sparse plumes in a virtual environment was also developed. Results indicated the ability of the algorithms to track plumes in 2D and 3D. The system has been tested with hardware in the loop (HIL) simulations and in flight using a CO2 gas sensor mounted to a multi-rotor UAV. The UAV is controlled by the plume tracking algorithm running on the ground control station (GCS).

Recent insights into microbial triggers of interleukin-10 production in the host and the impact on infectious disease pathogenesis

Since its initial description as a Th2-cytokine antagonistic to interferon-alpha and granulocyte-macrophage colony-stimulating factor, many studies have shown various anti-inflammatory actions of interleukin-10 (IL-10), and its role in infection as a key regulator of innate immunity. Studies have shown that IL-10 induced in response to microorganisms and their products plays a central role in shaping pathogenesis. IL-10 appears to function as both sword and shield in the response to varied groups of microorganisms in its capacity to mediate protective immunity against some organisms but increase susceptibility to other infections. The nature of IL-10 as a pleiotropic modulator of host responses to microorganisms is explained, in part, by its potent and varied effects on different immune effector cells which influence antimicrobial activity. A new understanding of how microorganisms trigger IL-10 responses is emerging, along with recent discoveries of how IL-10 produced during disease might be harnessed for better protective or therapeutic strategies. In this review, we summarize studies from the past 5 years that have reported the induction of IL-10 by different classes of pathogenic microorganisms, including protozoa, nematodes, fungi, viruses and bacteria and discuss the impact of this induction on the persistence and/or clearance of microorganisms in the host.

Phylogenetic lineage and pilus protein Spb1/SAN1518 affect opsonin-independent phagocytosis and intracellular survival of Group B Streptococcus

Opsonin-independent phagocytosis of Group B Streptococcus (GBS) is important in defense against neonatal GBS infections. A recent study indicated a role for GBS pilus in macrophage phagocytosis (Maisey et al Faseb J 22 2008 1715-24). We studied 163 isolates from different phylogenetic backgrounds and those possessing or lacking the gene encoding the pilus backbone protein, Spb1 (SAN1518, PI-2b) and spb1-deficient mutants of wild-type (WT) serotype III-3 GBS 874391 in non-opsonic phagocytosis assays using J774A.1 macrophages. Numbers of GBS phagocytosed differed up to 23-fold depending on phylogenetic background; isolates possessing spb1 were phagocytosed more than isolates lacking spb1. Comparing WT GBS and isogenic spb1-deficient mutants showed WT was phagocytosed better compared to mutants; Spb1 also enhanced intracellular survival as mutants were killed more efficiently. Complementation of mutants restored phagocytosis and resistance to killing in J774A.1 macrophages. Spb1 antiserum revealed surface expression in WT GBS and spatial distribution relative to capsular polysaccharide. spb1 did not affect macrophage nitric oxide and TNF-alpha responses; differences in phagocytosis did not correlate with N-acetyl d-glucosamine (from GBS cell-wall) according to enzyme-linked lectin-sorbent assay. Together, these findings support a role for phylogenetic lineage and Spb1 in opsonin-independent phagocytosis and intracellular survival of GBS in J774A.1 macrophages.

Current understanding of streptococcal urinary tract infection

Group B streptococcus (GBS), also known as Streptococcus agalactiae is a Gram-positive, β-hemolytic, chain-forming bacterium and a commensal within the genital tract flora in approximately 25% of healthy adult women (Campbell et al., 2000). The organism is a leading cause of serious infection in newborns, pregnant women, and older persons with chronic medical illness (Baker et al., Edwards&Baker, 2005). In neonates GBS infection most commonly causes pneumonia, meningitis, and sepsis. In addition to maternal cervicovaginal colonization and neonatal infection that can result from vertical transmission of GBS from mothers to their infants, the bacterium can also cause urinary tract infection (UTI). The spectrum of GBS UTI includes asymptomatic bacteriuria (ABU), cystitis, pyelonephritis, urethritis, and urosepsis (Bronsema et al., 1993, Edwards&Baker, 2005, Farley et al., 1993, Lefevre et al., 1991, McKenna et al., 2003, Munoz et al., 1992, Ulett et al., 2009). GBS ABU is particularly common among pregnant women, although those most at risk for cystitis due to GBS appear to be elderly individuals (Edwards&Baker, 2005, Falagas et al., 2006, Muller et al., 2006). In addition to acute and asymptomatic UTI other invasive diseases caused by GBS infection include skin infections, bacteraemia, pneumonia, arthritis, and endocarditis (Liston et al., 1979, Patil & Martin, 2010, Tissi et al., 1997, Trivalle et al., 1998). Thus, GBS is considered unique in terms of its ability to cause a spectrum of diseases in newborns and adult humans and its ability to colonize the genital tract of healthy women in a commensal-type manner...

Impacts and management of wild pigs Sus scrofa in Australia

Globally, wild or feral pigs Sus scrofa are a widespread and important pest. Mitigation of their impacts requires a sound understanding of those impacts and the benefits and limitations of different management approaches. Here, we review published and unpublished studies to provide a synopsis of contemporary understanding of wild pig impacts and management in Australia, and to identify important shortcomings. Wild pigs can have important impacts on biodiversity values, ecosystem functioning and agricultural production. However, many of these impacts remain poorly described, and therefore, difficult to manage effectively. Many impacts are highly variable, and innovative experimental and analytical approaches may be necessary to elucidate them. Most contemporary management programmes use lethal techniques to attempt to reduce pig densities, but it is often unclear how effective they are at reducing damage. We conclude that greater integration of experimental approaches into wild pig management programmes is necessary to improve our understanding of wild pig impacts, and our ability to manage those impacts effectively and efficiently.