https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:21992 Bacillus species were identified compared with healthy controls. PCR analyses revealed increased rates of detection of potentially pathogenic bacteria with Haemophilus influenzae detection associated with higher sputum levels of NE and IL-1β, while Streptococcus pneumoniae was more common in male ex-smokers with emphysema and a deficit in diffusion capacity. Conclusion: Non-pathogenic and pathogenic bacteria were altered in the sputum of patients with COPD. These observations highlight the potential to identify treatment and management strategies that both target specific bacterial pathogens and restore the microbial balance, which may lead to reductions in inflammation and subsequent improvements in lung health.]]> Wed 17 Nov 2021 16:31:05 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:10306 Wed 11 Apr 2018 16:25:22 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:22005 haemophilus influenzae and pharmacological inhibition in mouse and human macrophages augments phagocytosis, the production of reactive oxygen species, and microbicidal activity. Moreover, inhibition of miR-328 in respiratory models of infection, steroid-induced immunosuppression, and smoke-induced emphysema enhances bacterial clearance. Thus, miRNA pathways can be targeted in the lung to enhance host defence against a clinically relevant microbial infection and offer a potential new anti-microbial approach for the treatment of respiratory diseases.]]> Wed 11 Apr 2018 16:14:13 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:14161 Wed 11 Apr 2018 16:03:17 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:22120 Haemophilus influenzae (NTHi) is a prevalent bacterium found in a variety of chronic respiratory diseases. The role of this bacterium in the pathogenesis of lung inflammation is not well defined. In this study we examined the effect of NTHi on two important lung inflammatory processes 1), oxidative stress and 2), protease expression. Bronchoalveolar macrophages were obtained from 121 human subjects, blood neutrophils from 15 subjects, and human-lung fibroblast and epithelial cell lines from 16 subjects. Cells were stimulated with NTHi to measure the effect on reactive oxygen species (ROS) production and extracellular trap formation. We also measured the production of the oxidant, 3-nitrotyrosine (3-NT) in the lungs of mice infected with this bacterium. NTHi induced widespread production of 3-NT in mouse lungs. This bacterium induced significantly increased ROS production in human fibroblasts, epithelial cells, macrophages and neutrophils; with the highest levels in the phagocytic cells. In human macrophages NTHi caused a sustained, extracellular production of ROS that increased over time. The production of ROS was associated with the formation of macrophage extracellular trap-like structures which co-expressed the protease metalloproteinase-12. The formation of the macrophage extracellular trap-like structures was markedly inhibited by the addition of DNase. In this study we have demonstrated that NTHi induces lung oxidative stress with macrophage extracellular trap formation and associated protease expression. DNase inhibited the formation of extracellular traps.]]> Wed 11 Apr 2018 15:36:56 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:14153 Wed 11 Apr 2018 10:56:29 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:22102 mobA mutant of the host-adapted human pathogen Haemophilus influenzae. H. influenzae causes and contributes to a variety of acute and chronic diseases of the respiratory tract, and several enzymes of the DMSO reductase family are conserved and highly expressed in this bacterium. The mobA mutation caused a significant decrease in the activities of all Mo-enzymes present, and also resulted in a small defect in anaerobic growth. However, we did not detect a defect in in vitro biofilm formation nor in invasion and adherence to human epithelial cells in tissue culture compared to the wild-type. In a murine in vivo model, the mobA mutant showed only a mild attenuation compared to the wild-type. In summary, our data show that MobA is essential for the activities of molybdenum enzymes, but does not appear to affect the fitness of H. influenzae. These results suggest that MobA is unlikely to be a useful target for antimicrobials, at least for the purpose of treating H. influenzae infections.]]> Wed 11 Apr 2018 10:24:53 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:15242 Tue 11 Jun 2019 11:55:23 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:29749 Haemophilus influenzae is a host adapted human mucosal pathogen involved in a variety of acute and chronic respiratory tract infections, including chronic obstructive pulmonary disease and asthma, all of which rely on its ability to efficiently establish continuing interactions with the host. Here we report the characterization of a novel molybdenum enzyme, TorZ/MtsZ that supports interactions of H. influenzae with host cells during growth in oxygen-limited environments. Strains lacking TorZ/MtsZ showed a reduced ability to survive in contact with epithelial cells as shown by immunofluorescence microscopy and adherence/invasion assays. This included a reduction in the ability of the strain to invade human epithelial cells, a trait that could be linked to the persistence of H. influenzae. The observation that in a murine model of H. influenzae infection, strains lacking TorZ/MtsZ were almost undetectable after 72 h of infection, while ∼3.6 × 10³ CFU/mL of the wild type strain were measured under the same conditions is consistent with this view. To understand how TorZ/MtsZ mediates this effect we purified and characterized the enzyme, and were able to show that it is an S- and N-oxide reductase with a stereospecificity for S-sulfoxides. The enzyme converts two physiologically relevant sulfoxides, biotin sulfoxide and methionine sulfoxide (MetSO), with the kinetic parameters suggesting that MetSO is the natural substrate of this enzyme. TorZ/MtsZ was unable to repair sulfoxides in oxidized Calmodulin, suggesting that a role in cell metabolism/energy generation and not protein repair is the key function of this enzyme. Phylogenetic analyses showed that H. influenzae TorZ/MtsZ is only distantly related to the Escherichia coli TorZ TMAO reductase, but instead is a representative of a new, previously uncharacterized clade of molybdenum enzyme that is widely distributed within the Pasteurellaceae family of pathogenic bacteria. It is likely that MtsZ/TorZ has a similar role in supporting host/pathogen interactions in other members of the Pasteurellaceae, which includes both human and animal pathogens.]]> Thu 28 Oct 2021 12:36:21 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:45342 Thu 27 Oct 2022 15:17:41 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:14610 Sat 24 Mar 2018 08:20:47 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:21800 Haemophilus influenzae is one of the most commonly isolated bacteria. The relationship between chronic airway colonisation and the development of steroid-resistant neutrophilic asthma is unclear. Objectives: To investigate the relationship between H influenzae respiratory infection and neutrophilic asthma using mouse models of infection and ovalbumin (OVA)-induced allergic airways disease. Methods: BALB/c mice were intratracheally infected with H influenzae (day 10), intraperitoneally sensitised (day 0) and intranasally challenged (day 12–15) with OVA. Treatment groups were administered dexamethasone intranasally during OVA challenge. Infection, allergic airways disease, steroid sensitivity and immune responses were assessed (days 11, 16 and 21). Results: The combination of H influenzae infection and allergic airways disease resulted in chronic lung infection that was detected on days 11, 16 and 21 (21, 26 and 31 days after infection). Neutrophilic allergic airways disease and T helper 17 cell development were induced, which did not require active infection. Importantly, all features of neutrophilic allergic airways disease were steroid resistant. Toll-like receptor 4 expression and activation of phagocytes was reduced, but most significantly the influx and/or development of phagocytosing neutrophils and macrophages into the airways was inhibited. Conclusions: The combination of infection and allergic airways disease promotes bacterial persistence, leading to the development of a phenotype similar to steroid-resistant neutrophilic asthma and which may result from dysfunction in innate immune cells. This indicates that targeting bacterial infection in steroid-resistant asthma may have therapeutic benefit.]]> Sat 24 Mar 2018 07:59:21 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:22006 100/FVC. Total lung capacity was increased in HE+DR males. HE males had elevated responses to methacholine. Neonatal hyperoxia alters lung function at mid-adulthood, especially in males.]]> Sat 24 Mar 2018 07:15:55 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:22009 Chlamydia and Haemophilus lung infection-induced SSIAAD. We used these models to investigate the effects of clarithromycin and amoxicillin treatment on immune responses and airways hyper-responsiveness (AHR) in Ova-induced, T helper lymphocyte (Th) 2 -associated steroid-sensitive AAD and infection-induced Th1/Th17-associated SSIAAD compared with dexamethasone treatment. Results: Clarithromycin and amoxicillin had similar antimicrobial effects on infection. Amoxicillin did attenuate some features, but did not broadly suppress either form of AAD. It did restore steroid sensitivity in SSIAAD by reducing infection. In contrast, clarithromycin alone widely suppressed inflammation and AHR in both steroid-sensitive AAD and SSIAAD. This occurred through reductions in Th2 responses that drive steroid-sensitive eosinophilic AAD and tumour necrosis factor a and interleukin 17 responses that induce SSIAAD. Conclusions: Macrolides have broad anti-inflammatory effects in AAD that are likely independent of their antimicrobial effects. The specific responses that are suppressed are dependent upon the responses that dominate during AAD.]]> Sat 24 Mar 2018 07:15:55 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:22049 Sat 24 Mar 2018 07:15:53 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:21997 Sat 24 Mar 2018 07:14:33 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:22116 Streptococcus pneumoniae (Spn). The effect of Spn IMT on the development of asthma [allergic airways disease (AAD)] was determined in mice. Killed Spn was administered before, during or after ovalbumin sensitization, and the subsequent development of AAD was assessed. IMT attenuated T cell cytokine production, goblet cell hyperplasia, airways hyperresponsiveness (AHR), and eosinophil numbers in the blood, bronchoalveolar lavage fluid and peribronchial tissue. This indicates the potential of Spn as an IMT for asthma.]]> Sat 24 Mar 2018 07:13:18 AEDT ]]>