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Article ; Online: Prophage

Roshan Nepal / Ghais Houtak / Peter-John Wormald / Alkis James Psaltis / Sarah Vreugde

The Lancet Microbe, Vol 3, Iss 3, Pp e162-e

a crucial catalyst in infectious disease modulation

2022 Volume 163

Keywords	Medicine (General) ; R5-920 ; Microbiology ; QR1-502
Language	English
Publishing date	2022-03-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: APTC-EC-2A

Karen Hon / Sha Liu / Sophie Camens / George Spyro Bouras / Alkis James Psaltis / Peter-John Wormald / Sarah Vreugde

Microorganisms, Vol 10, Iss 102, p

A Lytic Phage Targeting Multidrug Resistant E. coli Planktonic Cells and Biofilms

2022 Volume 102

Abstract: Escherichia coli ( E. coli ) are common bacteria that colonize the human and animal gastrointestinal tract, where they help maintain a balanced microbiome. However, some E. coli strains are pathogenic and can cause serious infectious diseases and life- ... ...

Abstract	Escherichia coli ( E. coli ) are common bacteria that colonize the human and animal gastrointestinal tract, where they help maintain a balanced microbiome. However, some E. coli strains are pathogenic and can cause serious infectious diseases and life-threatening complications. Due to the overuse of antibiotics and limited development of novel antibiotics, the emergence of antibiotic-resistant strains has threatened modern medicine, whereby common infections can become lethal. Phage therapy has once again attracted interest in recent years as an alternative treatment option to antibiotics for severe infections with antibiotic-resistant strains. The aim of this study was to isolate and characterize phage against multi-drug resistant E. coli isolated from clinical samples and hospital wastewater. For phage isolation, wastewater samples were collected from The Queen Elizabeth Hospital (Adelaide, SA, Australia) followed by phage enrichment as required. Microbiological assays, electron microscopy and genomic sequencing were carried out to characterize the phage. From the 10 isolated E. coli phages, E. coli phage APTC-EC-2A was the most promising and could lyse 6/7 E. coli clinical isolates. APTC-EC-2A was stable at a broad pH range (3–11) and could lyse the host E. coli at temperatures ranging between 30–50 °C. Furthermore, APTC-EC-2A could kill E. coli in planktonic and biofilm form. Electron microscopy and genomic sequencing indicated the phage to be from the Myoviridae family and of lytic nature. In conclusion, the newly isolated phage APTC-EC-2A has the desired properties that support its potential for development as a therapeutic agent against therapy refractory E. coli infections.
Keywords	E. coli ; antimicrobial ; phage ; stability ; biofilm ; Biology (General) ; QH301-705.5
Subject code	500
Language	English
Publishing date	2022-01-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: APTC-C-SA01

Sha Liu / Karen Hon / George Spyro Bouras / Alkis James Psaltis / Keith Shearwin / Peter-John Wormald / Sarah Vreugde

International Journal of Molecular Sciences, Vol 23, Iss 6116, p

A Novel Bacteriophage Cocktail Targeting Staphylococcus aureus and MRSA Biofilms

2022 Volume 6116

Abstract: The high infection and mortality rate of methicillin-resistant Staphylococcus aureus (MRSA) necessitates the urgent development of new treatment strategies. Bacteriophages (phages) have several advantages compared to antibiotics for the treatment of ... ...

Abstract	The high infection and mortality rate of methicillin-resistant Staphylococcus aureus (MRSA) necessitates the urgent development of new treatment strategies. Bacteriophages (phages) have several advantages compared to antibiotics for the treatment of multi-drug-resistant bacterial infections, and thus provide a promising alternative to antibiotics. Here, S. aureus phages were isolated from patients and environmental sources. Phages were characterized for stability, morphology and genomic sequence and their bactericidal activity against the biofilm form of methicillin-susceptible Staphylococcus aureus (MSSA) and MRSA was investigated. Four S. aureus phages were isolated and tested against 51 MSSA and MRSA clinical isolates and reference strains. The phages had a broad host range of 82–94% individually and of >98% when combined and could significantly reduce the viability of S. aureus biofilms. The phages had a latent period of ≤20 min and burst size of >11 plaque forming units (PFU)/infected cell. Transmission electron microscopy (TEM) identified phages belonging to the family of Myoviridae . Genomic sequencing indicated the lytic nature of all four phages, with no identified resistance or virulence genes. The 4 phages showed a high complementarity with 49/51 strains (96%) sensitive to at least 2/4 phages tested. Furthermore, the frequency of bacteriophage insensitive mutant (BIM) generation was lower when the phages were combined into the phage cocktail APTC-C-SA01 than for bacteria exposed to each of the phages alone. In conclusion, APTC-C-SA01, containing four lytic S. aureus phages has the potential for further development as a treatment against MSSA and MRSA infections.
Keywords	S. aureus ; antimicrobial ; bacteriophage ; biofilm ; phage cocktail ; Biology (General) ; QH301-705.5 ; Chemistry ; QD1-999
Subject code	630
Language	English
Publishing date	2022-05-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Preclinical Development of a Bacteriophage Cocktail for Treating Multidrug Resistant Pseudomonas aeruginosa Infections

Sophie Camens / Sha Liu / Karen Hon / George Spyro Bouras / Alkis James Psaltis / Peter-John Wormald / Sarah Vreugde

Microorganisms, Vol 9, Iss 2001, p

2021 Volume 2001

Abstract: A Pseudomonas aeruginosa ( P. aeruginosa ) airway infection is one of the predominant causes contributing to the high morbidity and mortality rates in cystic fibrosis (CF) patients. The emergence of antibiotic resistant P. aeruginosa strains has led to ... ...

Abstract	A Pseudomonas aeruginosa ( P. aeruginosa ) airway infection is one of the predominant causes contributing to the high morbidity and mortality rates in cystic fibrosis (CF) patients. The emergence of antibiotic resistant P. aeruginosa strains has led to an urgent need for new therapeutic approaches. Bacteriophages (phages) are viruses that can infect and lyse specific bacteria, providing a potential alternative approach in targeting antibiotic-resistant strains. We aim to isolate and characterise novel P. aeruginosa phages for combination in a cocktail to kill P. aeruginosa. One particular phage, PA4, could lyse 14/20 clinical isolates as observed through spot assays. This phage could significantly reduce the growth of bacteria in vitro, as determined through planktonic adsorption and inhibition assays as well as crystal violet- and LIVE/DEAD-stained biofilm assays. A morphological and genomic analysis revealed that PA4 belongs to the Myoviridae family and contained 66,450 bp. The broad infectivity profile, good stability in various pH and temperature conditions, lytic ability and the absence of the absences of antibiotic resistance, toxic and lysogenic genes suggest that PA4 is a good candidate for clinical grade use. Overall, phage therapy represents a promising alternative treatment option to antibiotics when treating a P. aeruginosa infection.
Keywords	bacterial infection ; bacteriophage ; Pseudomonas aeruginosa ; cystic fibrosis ; multidrug resistance ; phage therapy ; Biology (General) ; QH301-705.5
Subject code	572
Language	English
Publishing date	2021-09-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: The effect of chemical and structural modifiers on the haemostatic process and cytotoxicity of the beta-chitin patch

Ahad Sabab / Sha Liu / Shari Javadiyan / C. John McAdam / Lyall R. Hanton / Alistair Jukes / Sarah Vreugde / Peter-John Wormald

Scientific Reports, Vol 11, Iss 1, Pp 1-

2021 Volume 15

Abstract: Abstract Beta-chitin patch has previously been proven to be an effective haemostat, but whether modifying the patch affects its efficacy and safety, remains unanswered. In this study, the patch was modified using polyethylene oxide, Pluronic-F127, ... ...

Abstract	Abstract Beta-chitin patch has previously been proven to be an effective haemostat, but whether modifying the patch affects its efficacy and safety, remains unanswered. In this study, the patch was modified using polyethylene oxide, Pluronic-F127, calcium, increased thickness or polyphosphate, and their effect on the process of haemostasis and cytotoxicity was tested and compared with standard-of-care, Surgicel and FloSeal. Whole blood collected from volunteers was applied to the patches to test their whole blood clotting and thrombin generation capacities, whilst platelet isolates were used to test their platelet aggregation ability. The fluid absorption capacity of the patches was tested using simulated body fluid. Cytotoxicity of the patches was tested using AlamarBlue assays and PC12 cells and the results were compared with the standard-of-care. In this study, beta-chitin patch modifications failed to improve its whole blood clotting, platelet aggregation and thrombin generation capacity. Compared to non-modified patch, modifications with polyethylene oxide or calcium reduced platelet aggregation and thrombin generation capacity, while increasing the thickness or adding polyphosphate decreased platelet aggregation capacity. The cytotoxicity assays demonstrated that the beta-chitin patches were non-toxic to cells. In vivo research is required to evaluate the safety and efficacy of the beta-chitin patches in a clinical setting.
Keywords	Medicine ; R ; Science ; Q
Subject code	630
Language	English
Publishing date	2021-09-01T00:00:00Z
Publisher	Nature Portfolio
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Cytokine-Induced Modulation of SARS-CoV2 Receptor Expression in Primary Human Nasal Epithelial Cells

Mahnaz Ramezanpour / Harrison Bolt / Karen Hon / George Spyro Bouras / Alkis James Psaltis / Peter-John Wormald / Sarah Vreugde

Pathogens, Vol 10, Iss 848, p

2021 Volume 848

Abstract: Background : Viral entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) via the spike protein enables endocytosis into host cells using the ACE2 receptor and TMPRSS2. The frequent upper respiratory tract symptoms of COVID-19 and the ... ...

Abstract	Background : Viral entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) via the spike protein enables endocytosis into host cells using the ACE2 receptor and TMPRSS2. The frequent upper respiratory tract symptoms of COVID-19 and the localization of the virus to the nasopharynx, the most common site of swabbing, indicate that the sinonasal mucosa may play an important role in SARS-CoV2 infection and viral replication. Methods: This paper investigates the presence of ACE2 receptor and TMPRESS2 expression in the primary human nasal epithelial cells (HNECs) from the following: chronic rhinosinusitis without nasal polyps (CRSsNP), CRS with nasal polyps (CRSwNP) and control (non-CRS) patients, and maps the expression changes when exposed to Th1, Th2, Th17-associated cytokines. Results: We found that ACE2 and TMPRSS2 expression was higher in control HNECs than CRSwNP HNECs, and that both ACE2 and TMPRSS2 were downregulated further by Th2 cytokines in CRSwNP HNECs. Conclusions: This indicates an immune dysregulated state of CRSwNP mucosa, which normally contributes to a chronic inflammatory state, and might support an altered susceptibility to SARS-CoV2 infection and transmission.
Keywords	chronic rhinosinusitis ; ACE2 ; TMPRSS2 ; human nasal epithelial cells ; Medicine ; R
Subject code	570
Language	English
Publishing date	2021-07-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Corynebacterium accolens Has Antimicrobial Activity against Staphylococcus aureus and Methicillin-Resistant S. aureus Pathogens Isolated from the Sinonasal Niche of Chronic Rhinosinusitis Patients

Martha Alemayehu Menberu / Sha Liu / Clare Cooksley / Andrew James Hayes / Alkis James Psaltis / Peter-John Wormald / Sarah Vreugde

Pathogens, Vol 10, Iss 2, p

2021 Volume 207

Abstract: Corynebacterium accolens is the predominant species of the healthy human nasal microbiota, and its relative abundance is decreased in the context of chronic rhinosinusitis (CRS). This study aimed to evaluate the antimicrobial potential of C. accolens ... ...

Abstract	Corynebacterium accolens is the predominant species of the healthy human nasal microbiota, and its relative abundance is decreased in the context of chronic rhinosinusitis (CRS). This study aimed to evaluate the antimicrobial potential of C. accolens isolated from a healthy human nasal cavity against planktonic and biofilm growth of Staphylococcus aureus ( S. aureus ) and methicillin-resistant S. aureus (MRSA) clinical isolates (CIs) from CRS patients. Nasal swabs from twenty non-CRS control subjects were screened for the presence of C. accolens using microbiological and molecular techniques. C. accolens CIs and their culture supernatants were tested for their antimicrobial activity against eight S. aureus and eight MRSA 4CIs and S. aureus ATCC25923. The anti-biofilm potential of C. accolens cell-free culture supernatants (CFCSs) on S. aureus biofilms was also assessed. Of the 20 nasal swabs, 10 C. accolens CIs were identified and confirmed with rpoB gene sequencing. All isolates showed variable antimicrobial activity against eight out of 8 S. aureus and seven out of eight MRSA CIs. Culture supernatants from all C. accolens CIs exhibited a significant dose-dependent antibacterial activity ( p < 0.05) against five out of five representative S. aureus and MRSA CIs. This inhibition was abolished after proteinase K treatment. C. accolens supernatants induced a significant reduction in metabolic activity and biofilm biomass of S. aureus and MRSA CIs compared to untreated growth control ( p < 0.05). C. accolens exhibited antimicrobial activity against S. aureus and MRSA CIs in both planktonic and biofilm forms and holds promise for the development of innovative probiotic therapies to promote sinus health.
Keywords	chronic rhinosinusitis ; Corynebacterium accolens ; microbiota ; sinus health ; Medicine ; R
Subject code	616
Language	English
Publishing date	2021-02-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Primary human nasal epithelial cells

Mahnaz Ramezanpour / Harrison Bolt / Alkis James Psaltis / Peter-John Wormald / Sarah Vreugde

Scientific Reports, Vol 8, Iss 1, Pp 1-

a source of poly (I:C) LMW-induced IL-6 production

2018 Volume 8

Abstract: Abstract Infection plays a significant role in the relapse of chronic rhinosinusitis (CRS), however, the role of primary human nasal epithelial cells (HNECs) in this process is largely unknown. Here, we determined the effect of Toll-like receptor (TLR) ... ...

Abstract	Abstract Infection plays a significant role in the relapse of chronic rhinosinusitis (CRS), however, the role of primary human nasal epithelial cells (HNECs) in this process is largely unknown. Here, we determined the effect of Toll-like receptor (TLR) agonists and inflammatory cytokines on mucosal barrier integrity and immune response of HNECs. TLR 1–9 agonists and inflammatory cytokines were applied to submerged and/or air-liquid interface (ALI) cultures of HNECs from CRS patients and controls for 24 hours. Interleukin-6 (IL-6) protein levels were determined by ELISA. Mucosal barrier integrity was measured via Transepithelial Electrical Resistance and passage of fluorescently-labelled dextrans. IL-1β and IFN- γ significantly increased IL-6 production in HNECs derived from CRS patients and controls, however, a dose-dependent effect was observed in CRS-derived HNECs only. Stimulation with Poly (I:C) LMW induced a 15 to 17 fold increase in IL-6 production by HNEC-ALI control cells (p < 0.05) and HNEC-ALI-CRS cells (p = 0.004) whilst a 2.5 fold increase was observed in CRS HNEC submerged cultures. Priming of cells with Poly (I:C) LMW reduced subsequent IL-6 secretion upon stimulation with TLR 2–4 agonists. Poly (I:C) LMW exerts a potent pro-inflammatory effect on HNECs and reduces a subsequent immune activation by TLR agonists.
Keywords	Medicine ; R ; Science ; Q
Subject code	610
Language	English
Publishing date	2018-07-01T00:00:00Z
Publisher	Nature Publishing Group
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Deferiprone has anti-inflammatory properties and reduces fibroblast migration in vitro

Mahnaz Ramezanpour / Jason L. P. Smith / Mian Li Ooi / Michael Gouzos / Alkis J. Psaltis / P. J. Wormald / Sarah Vreugde

Scientific Reports, Vol 9, Iss 1, Pp 1-

2019 Volume 9

Abstract: Abstract Normal wound healing is a highly regulated and coordinated process. However, tissue injury often results in inflammation with excessive scar tissue formation after 40–70% of operations. Here, we evaluated the effect of the iron chelator ... ...

Abstract	Abstract Normal wound healing is a highly regulated and coordinated process. However, tissue injury often results in inflammation with excessive scar tissue formation after 40–70% of operations. Here, we evaluated the effect of the iron chelator deferiprone on inflammation and the migration of primary nasal fibroblasts and primary human nasal epithelial cells (HNECs) in vitro. The cytotoxicity of deferiprone was examined by the lactate dehydrogenase assay on primary nasal fibroblasts and air-liquid interface (ALI) cultures of HNECs. Wound closure was observed in scratch assays by using time-lapse confocal scanning laser microscopy. Interleukin-6 (IL-6) and type I and III collagen protein levels were determined by ELISA. Intracellular Reactive Oxygen Species (ROS) activity was measured by utilizing the fluorescent probe H2DCFDA. Deferiprone at 10 mM concentration was non-toxic to primary fibroblasts and HNECs for up to 48 hours application. Deferiprone had significant dose-dependent inhibitory effects on the migration, secreted collagen production and ROS release by primary nasal fibroblasts. Deferiprone blocked Poly (I:C)-induced IL-6 production by HNECs but did not alter their migration in scratch assays. Deferiprone has the potential to limit scar tissue formation and should be considered in future clinical applications.
Keywords	Medicine ; R ; Science ; Q
Language	English
Publishing date	2019-02-01T00:00:00Z
Publisher	Nature Publishing Group
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Sub-Inhibitory Clindamycin and Azithromycin reduce S. aureus Exoprotein Induced Toxicity, Inflammation, Barrier Disruption and Invasion

Hua Hu / Mahnaz Ramezanpour / Andrew J Hayes / Sha Liu / Alkis J Psaltis / Peter-John Wormald / Sarah Vreugde

Journal of Clinical Medicine, Vol 8, Iss 10, p

2019 Volume 1617

Abstract: Background: Chronic rhinosinusitis (CRS) is defined as a chronic inflammation of the nose and paranasal sinus mucosa associated with relapsing infections—particularly with S. aureus. Long-term treatments with protein synthesis inhibitor antibiotics have ... ...

Abstract	Background: Chronic rhinosinusitis (CRS) is defined as a chronic inflammation of the nose and paranasal sinus mucosa associated with relapsing infections—particularly with S. aureus. Long-term treatments with protein synthesis inhibitor antibiotics have been proposed to reduce inflammation in the context chronic severe inflammatory airway pathologies, including CRS. This study assessed the effect of subinhibitory clindamycin and azithromycin on S. aureus exoprotein induced inflammation, toxicity and invasiveness. Methods: S. aureus ATCC51650 and two clinical isolates grown in planktonic and biofilm form were treated with subinhibitory clindamycin and azithromycin. Exoproteins were collected and applied to primary human nasal epithelial cells (HNECs) in monolayers and at air-liquid interface. This was followed by lactate dehydrogenase (LDH), enzyme-linked immunosorbent assay (ELISA), Transepithelial Electrical Resistance (TEER) and paracellular permeability assays to assess the effect on cell toxicity, inflammatory cytokine production and mucosal barrier structure and function, respectively. The effect of these treatments was tested as well on the S. aureus invasiveness of HNECs. Results: Subinhibitory clindamycin reduced S. aureus exoprotein production in planktonic and biofilm form, thereby blocking exoprotein-induced toxicity, reversing its detrimental effects on mucosal barrier structure and function and modulating its inflammatory properties. Sub-inhibitory azithromycin had similar effects—albeit to a lesser extent. Furthermore, clindamycin—but not azithromycin—treated S. aureus lost its invasive capacity of HNECs. Conclusion: Subinhibitory clindamycin and azithromycin reduce S. aureus exoprotein production, thereby modulating the inflammatory cascade by reducing exoprotein-induced toxicity, inflammation, mucosal barrier disruption and invasiveness.
Keywords	chronic rhinosinusitis ; clindamycin ; azithromycin ; s. aureus ; exoprotein ; sub-inhibitory ; mucosal barrier ; Medicine ; R
Subject code	616
Language	English
Publishing date	2019-10-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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