The DmsABC Sulfoxide Reductase Supports Virulence in Non-typeable Haemophilus influenzae

Although molybdenum-containing enzymes are well-established as having a key role in bacterial respiration, it is increasingly recognized that some may also support bacterial virulence. Here, we show that DmsABC, a putative dimethylsulfoxide (DMSO) reductase, is required for fitness of the respiratory pathogen Haemophilus influenzae (Hi) in different models of infection. Expression of the dmsABC operon increased with decreasing oxygen availability, but despite this, a Hi2019ΔdmsA strain did not show any defects in anaerobic growth on chemically defined medium (CDM), and viability was also unaffected. Although Hi2019ΔdmsA exhibited increased biofilm formation in vitro and greater resistance to hypochlorite killing compared to the isogenic wild-type strain, its survival in contact with primary human neutrophils, in infections of cultured tissue cells, or in a mouse model of lung infection was reduced compared to Hi2019WT. The tissue cell infection model revealed a two-fold decrease in intracellular survival, while in the mouse model of lung infection Hi2019ΔdmsA was strongly attenuated and below detection levels at 48 h post-inoculation. While Hi2019WT was recovered in approximately equal numbers from bronchoalveolar lavage fluid (BALF) and lung tissue, survival of Hi2019ΔdmsA was reduced in lung tissue compared to BALF samples, indicating that Hi2019ΔdmsA had reduced access to or survival in the intracellular niche. Our data clearly indicate for the first time a role for DmsABC in H. influenzae infection and that the conditions under which DmsABC is required in this bacterium are closely linked to interactions with the host.

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Imaging of bioluminescent Klebsiella pneumoniae induced pulmonary infection in an immunosuppressed mouse model

Journal of International Medical Research ◽

10.1177/0300060520956473 ◽

2020 ◽

Vol 48 (10) ◽

pp. 030006052095647

Author(s):

Xing Hu ◽

Yun Cai ◽

Yuhang Wang ◽

Rui Wang ◽

Jin Wang ◽

...

Keyword(s):

Klebsiella Pneumoniae ◽

Mouse Model ◽

Real Time ◽

Imaging System ◽

Lung Infection ◽

Infection Model ◽

Immunodeficient Mice ◽

Infection Models ◽

Infection Disease ◽

Immunocompetent Mice

Objective To establish a mouse model of bioluminescent Klebsiella pneumoniae-induced lung infection, under different infection states after pretreatment with various dosages of cyclophosphamide (CTX). Methods A K. pneumoniae strain carrying the luxCDABE operon was used to infect immunocompetent mice (intraperitoneal injection of saline at 4 days and 1 day prior to experimental lung infection) and immunodeficient mice (50 mg/kg CTX at 4 days and 50 mg/kg CTX at 1 day prior to lung infection; or 150 mg/kg CTX at 4 days and 100 mg/kg CTX at 1 day prior to lung infection). Disease progression was monitored in living mice using a bioluminescence imaging system. The bioluminescent images, bacterial loads in lungs, blood cytological changes and histopathology of lungs were analysed. Results K. pneumoniae-induced lung infection models were established in mice pretreated with CTX. Different doses of CTX led to different severities of lung infection. Mice pretreated with 150/100 mg/kg CTX were more suitable for real-time monitoring as they had more typical bioluminescent images of lung infection, more obvious changes in the bioluminescent intensity values, more bacterial colonies in the lungs and more distinct pulmonary pathological changes. Conclusions A stable bioluminescent K. pneumonia-induced lung infection model was successfully established in mice pretreated with CTX, which can be semi-quantitatively monitored in real-time.

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Curcumin alone and in combination with augmentin protects against pulmonaryinflammation and acute lung injury generated during Klebsiella pneumoniae B5055-induced lung infection in BALB/c mice

Journal of Medical Microbiology ◽

10.1099/jmm.0.016873-0 ◽

2010 ◽

Vol 59 (4) ◽

pp. 429-437 ◽

Cited By ~ 36

Author(s):

Shruti Bansal ◽

Sanjay Chhibber

Keyword(s):

Klebsiella Pneumoniae ◽

Mouse Model ◽

Lung Tissue ◽

Inflammatory Mediators ◽

Bacterial Load ◽

Neutrophil Infiltration ◽

Lung Infection ◽

Control Group ◽

Intranasal Route ◽

Anti Inflammatory

Acute lung injuries due to acute lung infections remain a major cause ofmortality. Thus a combination of an antibiotic and a compound with immunomodulatoryand anti-inflammatory activities can help to overcome acute lung infection-inducedinjuries. Curcumin derived from the rhizome of turmeric has been used fordecades and it exhibits anti-inflammatory, anti-carcinogenic, immunomodulatoryproperties by downregulation of various inflammatory mediators. Keeping theseproperties in mind, we investigated the anti-inflammatory properties of curcuminin a mouse model of acute inflammation by introducing Klebsiella pneumoniae B5055 into BALB/c mice via the intranasal route. Intranasal instillationof bacteria in this mouse model of acute pneumonia-induced inflammation resultedin a significant increase in neutrophil infiltration in the lungs along withincreased production of various inflammatory mediators [i.e. malondialdehyde (MDA),myeloperoxidase (MPO), nitric oxide (NO), tumour necrosisfactor (TNF)-α] in the lung tissue. The animalsthat received curcumin alone orally or in combination with augmentin, 15 daysprior to bacterial instillation into the lungs via the intranasal route, showeda significant (P <0.05) decrease in neutrophil influxinto the lungs and a significant (P <0.05) decreasein the production of MDA, NO, MPO activity and TNF-α levels.Augmentin treatment alone did not decrease the MDA, MPO, NO and TNF-α levels significantly (P >0.05) as compared tothe control group. We therefore conclude that curcumin ameliorates lung inflammationinduced by K. pneumoniae B5055 without significantly (P <0.05) decreasing the bacterial load in the lung tissue whereasaugmentin takes care of bacterial proliferation. Hence, curcumin can be usedas an adjunct therapy along with antibiotics as an anti-inflammatory or animmunomodulatory agent in the case of acute lung infection.

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A Novel Zinc Binding System, ZevAB, Is Critical for Survival of Nontypeable Haemophilus influenzae in a Murine Lung Infection Model

Infection and Immunity ◽

10.1128/iai.05135-11 ◽

2011 ◽

Vol 79 (8) ◽

pp. 3366-3376 ◽

Cited By ~ 26

Author(s):

Charles V. Rosadini ◽

Jeffrey D. Gawronski ◽

Daniel Raimunda ◽

José M. Argüello ◽

Brian J. Akerley

Keyword(s):

Haemophilus Influenzae ◽

Respiratory Infections ◽

Bacterial Pathogen ◽

Lung Infection ◽

Lung Model ◽

Mouse Lung ◽

Infection Model ◽

Nontypeable Haemophilus Influenzae ◽

Content Type ◽

Lung Colonization

ABSTRACTNontypeableHaemophilus influenzae(NTHI) is a Gram-negative bacterial pathogen that causes upper and lower respiratory infections. Factors required for pulmonary infection by NTHI are not well understood. Previously, using high-throughput insertion tracking by deep sequencing (HITS), putative lung colonization factors were identified. Also, previous research indicates that secreted disulfide-dependent factors are important for virulence ofH. influenzae. In the present study, HITS data were compared with an informatics-based list of putative substrates of the periplasmic oxidoreductase DsbA to find and characterize secreted virulence factors. This analysis resulted in identification of the “zinc bindingessential forvirulence” (zev) locus consisting ofzevA(HI1249) andzevB(HI1248). NTHI mutants ofzevAandzevBgrew normally in rich medium but were defective for colonization in a mouse lung model. Mutants also exhibited severe growth defects in medium containing EDTA and were rescued by supplementation with zinc. Additionally, purified recombinant ZevA was found to bind to zinc with high affinity. Together, these data demonstrate thatzevABis a novel virulence factor important for zinc utilization ofH. influenzaeunder conditions where zinc is limiting. Furthermore, evidence presented here suggests that zinc limitation is likely an important mechanism for host defense against pathogens during lung infection.

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Generation of a Transgenic Mouse Model of Middle East Respiratory Syndrome Coronavirus Infection and Disease

Journal of Virology ◽

10.1128/jvi.03427-14 ◽

2015 ◽

Vol 89 (7) ◽

pp. 3659-3670 ◽

Cited By ~ 135

Author(s):

Anurodh Shankar Agrawal ◽

Tania Garron ◽

Xinrong Tao ◽

Bi-Hung Peng ◽

Maki Wakamiya ◽

...

Keyword(s):

Middle East ◽

Animal Models ◽

Mouse Model ◽

Transgenic Mouse ◽

Nonhuman Primates ◽

Lung Infection ◽

Transgenic Mouse Model ◽

Middle East Respiratory Syndrome ◽

Mouse Lung ◽

Infection Model

ABSTRACTThe emergence of Middle East respiratory syndrome-coronavirus (MERS-CoV) in the Middle East since 2012 has caused more than 900 human infections with ∼40% mortality to date. Animal models are needed for studying pathogenesis and for development of preventive and therapeutic agents against MERS-CoV infection. Nonhuman primates (rhesus macaques and marmosets) are expensive models of limited availability. Although a mouse lung infection model has been described using adenovirus vectors expressing human CD26/dipeptidyl peptidase 4 (DPP4), it is believed that a transgenic mouse model is needed for MERS-CoV research. We have developed this transgenic mouse model as indicated in this study. We show that transgenic mice globally expressing hCD26/DPP4 were fully permissive to MERS-CoV infection, resulting in relentless weight loss and death within days postinfection. High infectious virus titers were recovered primarily from the lungs and brains of mice at 2 and 4 days postinfection, respectively, whereas viral RNAs were also detected in the heart, spleen, and intestine, indicating a disseminating viral infection. Infected Tg+mice developed a progressive pneumonia, characterized by extensive inflammatory infiltration. In contrast, an inconsistent mild perivascular cuffing was the only pathological change associated with the infected brains. Moreover, infected Tg+mice were able to activate genes encoding for many antiviral and inflammatory mediators within the lungs and brains, coinciding with the high levels of viral replication. This new and unique transgenic mouse model will be useful for furthering knowledge of MERS pathogenesis and for the development of vaccine and treatments against MERS-CoV infection.IMPORTANCESmall and economical animal models are required for the controlled and extensive studies needed for elucidating pathogenesis and development of vaccines and antivirals against MERS. Mice are the most desirable small-animal species for this purpose because of availability and the existence of a thorough knowledge base, particularly of genetics and immunology. The standard small animals, mice, hamsters, and ferrets, all lack the functional MERS-CoV receptor and are not susceptible to infection. So, initial studies were done with nonhuman primates, expensive models of limited availability. A mouse lung infection model was described where a mouse adenovirus was used to transfect lung cells for receptor expression. Nevertheless, all generally agree that a transgenic mouse model expressing the DPP4 receptor is needed for MERS-CoV research. We have developed this transgenic mouse model as indicated in this study. This new and unique transgenic mouse model will be useful for furthering MERS research.

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Targeting Surface Protein SasX by Active and Passive Vaccination To Reduce Staphylococcus aureus Colonization and Infection

Infection and Immunity ◽

10.1128/iai.02951-14 ◽

2015 ◽

Vol 83 (5) ◽

pp. 2168-2174 ◽

Cited By ~ 12

Author(s):

Qian Liu ◽

Xin Du ◽

Xufen Hong ◽

Tianming Li ◽

Bing Zheng ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Passive Immunization ◽

Surface Protein ◽

Lung Infection ◽

Active Immunization ◽

Human Neutrophils ◽

Infection Model ◽

Nasal Colonization ◽

Content Type ◽

Infection Models

SasX is a recently described surface protein ofStaphylococcus aureusthat is linked to the epidemic success of hospital-associated methicillin-resistant clones, in particular in Asia. It enhances nasal colonization and virulence in skin and lung infection models. Here, we evaluated the potential of SasX as a vaccine component in passive and active immunization efforts using mouse infection models. We found that SasX induced a specific immune response predominantly based on IgG1 antibodies. Active immunization with recombinant SasX or passive immunization with rabbit polyclonal anti-SasX IgG significantly decreased the size of lesions caused byS. aureusin a skin infection model. Furthermore, active immunization reduced acute lung injury in a lung infection model. Moreover, active or passive immunization significantly reducedS. aureuscolonization in a nasal colonization model. Finally, anti-SasX IgG enhanced the susceptibility ofS. aureusto killing by human neutrophils. We conclude that SasX is a potential target for therapeutics or vaccines designed to moderate colonization and infection bysasX-positive epidemic strains ofS. aureus.

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Activity and local delivery of azithromycin in a mouse model of Haemophilus influenzae lung infection.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.36.7.1412 ◽

1992 ◽

Vol 36 (7) ◽

pp. 1412-1417 ◽

Cited By ~ 20

Author(s):

E Vallee ◽

E Azoulay-Dupuis ◽

J J Pocidalo ◽

E Bergogne-Berezin

Keyword(s):

Mouse Model ◽

Haemophilus Influenzae ◽

Lung Infection ◽

Local Delivery

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An epitope-based malaria vaccine targeting the junctional region of circumsporozoite protein

npj Vaccines ◽

10.1038/s41541-020-00274-4 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Lucie Jelínková ◽

Hugo Jhun ◽

Allison Eaton ◽

Nikolai Petrovsky ◽

Fidel Zavala ◽

...

Keyword(s):

Mouse Model ◽

Malaria Vaccine ◽

High Titer ◽

Circumsporozoite Protein ◽

Infection Model ◽

Vaccine Platform ◽

Junctional Region ◽

Mouse Infection Model ◽

Virus Like Particle ◽

Major Surface

AbstractA malaria vaccine that elicits long-lasting protection and is suitable for use in endemic areas remains urgently needed. Here, we assessed the immunogenicity and prophylactic efficacy of a vaccine targeting a recently described epitope on the major surface antigen on Plasmodium falciparum sporozoites, circumsporozoite protein (CSP). Using a virus-like particle (VLP)-based vaccine platform technology, we developed a vaccine that targets the junctional region between the N-terminal and central repeat regions of CSP. This region is recognized by monoclonal antibodies, including mAb CIS43, that have been shown to potently prevent liver invasion in animal models. We show that CIS43 VLPs elicit high-titer and long-lived anti-CSP antibody responses in mice and is immunogenic in non-human primates. In mice, vaccine immunogenicity was enhanced by using mixed adjuvant formulations. Immunization with CIS43 VLPs conferred partial protection from malaria infection in a mouse model, and passive transfer of serum from immunized macaques also inhibited parasite liver invasion in the mouse infection model. Our findings demonstrate that a Qβ VLP-based vaccine targeting the CIS43 epitope combined with various adjuvants is highly immunogenic in mice and macaques, elicits long-lasting anti-CSP antibodies, and inhibits parasite infection in a mouse model. Thus, the CIS43 VLP vaccine is a promising pre-erythrocytic malaria vaccine candidate.

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Haemophilus influenzae causes cellular trans-differentiation in human bronchial epithelia

Innate Immunity ◽

10.1177/1753425921994906 ◽

2021 ◽

Vol 27 (3) ◽

pp. 251-259

Author(s):

Michael Glöckner ◽

Sebastian Marwitz ◽

Kristina Rohmann ◽

Henrik Watz ◽

Dörte Nitschkowski ◽

...

Keyword(s):

Epithelial Cells ◽

Haemophilus Influenzae ◽

Bronchial Epithelium ◽

Bronchial Epithelial Cells ◽

Respiratory Pathogen ◽

Chronic Obstructive ◽

Bronchial Epithelial ◽

Extracellular Matrix Components ◽

The Impact ◽

Primary Bronchial Epithelial Cells

Non-typeable Haemophilus influenzae (NTHi) is the most common respiratory pathogen in patients with chronic obstructive disease. Limited data is available investigating the impact of NTHi infections on cellular re-differentiation processes in the bronchial mucosa. The aim of this study was to assess the effects of stimulation with NTHi on the bronchial epithelium regarding cellular re-differentiation processes using primary bronchial epithelial cells harvested from infection-free patients undergoing bronchoscopy. The cells were then cultivated using an air-liquid interface and stimulated with NTHi and TGF-β. Markers of epithelial and mesenchymal cells were analyzed using immunofluorescence, Western blot and qRT-PCR. Stimulation with both NTHi and TGF-ß led to a marked increase in the expression of the mesenchymal marker vimentin, while E-cadherin as an epithelial marker maintained a stable expression throughout the experiments. Furthermore, expression of collagen 4 and the matrix-metallopeptidases 2 and 9 were increased after stimulation, while the expression of tissue inhibitors of metallopeptidases was not affected by pathogen stimulation. In this study we show a direct pathogen-induced trans-differentiation of primary bronchial epithelial cells resulting in a co-localization of epithelial and mesenchymal markers and an up-regulation of extracellular matrix components.

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Protective Effects of Korean Herbal Remedy against Airway Inflammation in an Allergic Asthma by Suppressing Eosinophil Recruitment and Infiltration in Lung

Antioxidants ◽

10.3390/antiox10010006 ◽

2020 ◽

Vol 10 (1) ◽

pp. 6

Author(s):

Soyon Yoon ◽

Seokcheon Song ◽

Jae Woo Shin ◽

Sini Kang ◽

Hye Young Kim ◽

...

Keyword(s):

Mouse Model ◽

Allergic Asthma ◽

Lung Tissue ◽

Oral Delivery ◽

Herbal Remedy ◽

Periodic Acid ◽

Lymphoid Cells ◽

Lung Epithelial Cells ◽

Eosinophil Infiltration ◽

Control Group

The increasing prevalence of allergic asthma has become the world’s major health issue. Current treatments for allergic asthma focus on treating symptoms, while permanent cures still remain undiscovered. In this study, we investigated the effect of Korean traditional herbal remedy, Pyunkang-tang (PGT)—composed of six plants—on asthma alleviation in a mouse model. The PGT mixture was orally gavaged to mice (PM group, 20 mg/mouse/day) from 7 days before sensitization with ovalbumin (OVA) (day −7). On day 0 and day 14, mice from OVA-control (n = 9) and PM group (n = 8) were sensitized with OVA and alum through intraperitoneal injection. On days 18~20, OVA was challenged to mice through nasal injection and sacrificed next day. Cell profile in lung tissue was analyzed by flow cytometry and RT-qPCR analysis, and the number of eosinophils and expression of siglec-F were significantly reduced in the PM group. Lung tissue was examined with hematoxylin and eosin (H&E) and Alcian blue/periodic acid–Schiff (AB-PAS) staining. Noticeably reduced eosinophil infiltration around bronchioles was displayed in the PM group compared to the OVA-control group. Furthermore, PGT-treated mice showed a significant reduction in IL-13 and a mild reduction in IL-5 in lungs. A decreasing tendency of IL-5/13 (+) CD4+ T cells and IL-13(+) innate lymphoid cells (ILCs) and a significant reduction in IL5(+) ILCs were also observed. When treating PGT on murine lung epithelial cells stimulated by papain, there was a significant reduction in IL-33 mRNA expression levels. Taken together, oral delivery of PGT successfully alleviated asthmatic responses provoked by OVA in a mouse model and could lead to novel therapies for allergic asthma.

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