- Awarded PhD in molecular microbiology at the University of Sydney in 2005 with 16 years of biology lab experience in ... moreAwarded PhD in molecular microbiology at the University of Sydney in 2005 with 16 years of biology lab experience in translational clinical research and achieved over 80 scientific publications in following area:
• Bacterial biofilms and microbiome in medical devices
• Breast implant associated Anaplastic large-cell lymphoma
• Surgical infection prevention and control
• Dry surface biofilms characterisation and removal
• Molecular insight of diabetic foot infections
• Combination therapy of bacterial biofilms in chronic wounds
• Cystic fibrosis lung infections
• Host pathogen interactions
Personal skills and achievements
• Ability to work in a busy environment with resources shared between multiple departments and teams
• A flexible, positive, "can do" attitude with a willingness to adapt and learn
• Managing research team, supervising research assistants and over 10 high degree research students
• Published over 80 scientific research papers and reviewed over 80 scientific research papers
• Presented at over 30 scientific conferences locally and internationally
https://scholar.google.com.au/citations?user=8ETc1S0AAAAJ
https://publons.com/researcher/1625899/honghua-hu/edit
Staphylococcus aureus biofilms are resistant to both antibiotics and disinfectants. As Staphylococci cell walls are an important defence mechanism, we sought to examine changes to the bacterial cell wall under different growth conditions.... more
Staphylococcus aureus biofilms are resistant to both antibiotics and disinfectants. As Staphylococci cell walls are an important defence mechanism, we sought to examine changes to the bacterial cell wall under different growth conditions. Cell walls of S. aureus grown as 3-day hydrated biofilm, 12-day hydrated biofilm, and 12-day dry surface biofilm (DSB) were compared to cell walls of planktonic organisms. Additionally, proteomic analysis using high-throughput tandem mass tag-based mass spectrometry was performed. Proteins involved in cell wall synthesis in biofilms were upregulated in comparison to planktonic growth. Bacterial cell wall width (measured by transmission electron microscopy) and peptidoglycan production (detected using a silkworm larva plasma system) increased with biofilm culture duration (p < 0.001) and dehydration (p = 0.002). Similarly, disinfectant tolerance was greatest in DSB, followed by 12-day hydrated biofilm and then 3-day biofilm, and it was least in t...
Research Interests:
Orthopedic implants, such as screws, are provided in a non-sterile state and must be reprocessed before each use, therefore they may be subjected to multiple reprocessing cycles until they are implanted in the patient. The effect of these... more
Orthopedic implants, such as screws, are provided in a non-sterile state and must be reprocessed before each use, therefore they may be subjected to multiple reprocessing cycles until they are implanted in the patient. The effect of these various reprocessing cycles on the quality and safety of these implants has been a subject of concern and discussion around the world. In this narrative review, we discuss the four main challenges associated with supplying these non-sterile implants to the same standard, with respect to their quality and safety, as implants that are provided sterile: microbiological contamination (focusing on biofilm), non-microbiological contamination, surface damage, and their acquisition in surgical trays from loaner companies.
Research Interests:
Oral cancer is a major global health problem with high incidence and low survival rates. The oral cavity contains biofilms as dental plaques that harbour both Gram-negative and Gram-positive bacterial antigens, lipopolysaccharide (LPS)... more
Oral cancer is a major global health problem with high incidence and low survival rates. The oral cavity contains biofilms as dental plaques that harbour both Gram-negative and Gram-positive bacterial antigens, lipopolysaccharide (LPS) and lipoteichoic acid (LTA), respectively. LPS and LTA are known to stimulate cancer cell growth, and the bioactive phytochemical capsaicin has been reported to reverse this effect. Here, we tested the efficacy of oral cancer chemotherapy treatment with capsaicin in the presence of LPS, LTA or the combination of both antigens. LPS and LTA were administered to Cal 27 oral cancer cells prior to and/or concurrently with capsaicin, and the treatment efficacy was evaluated by measuring cell proliferation and apoptotic cell death. We found that while capsaicin inhibits oral cancer cell proliferation and metabolism (MT Glo assay) and increases cell death (Trypan blue exclusion assay and Caspase 3/7 expression), its anti-cancer effect was significantly reduce...
Research Interests:
Objectives: To evaluate the efficacy of double manual cleaning (DMC) with enzymatic followed by alkaline detergent for removing biofilm on hinged surgical instruments compared to automated cleaning by the washer-disinfector. Methods:... more
Objectives: To evaluate the efficacy of double manual cleaning (DMC) with enzymatic followed by alkaline detergent for removing biofilm on hinged surgical instruments compared to automated cleaning by the washer-disinfector. Methods: Biofilm of Staphylococcus aureus (ATCC 25923) was formed in vitro on hemostatic forceps (Fig. 1). Biofilm-covered forceps were rinsed in distilled water and subjected to one of the following cleaning regimes (n = 5 forceps each): Group 1 forceps were soaked in sterile water for 5 minutes. Group 2-DMC forceps were soaked in enzymatic detergent, brushed 5 times on each face, rinsed with filtrated water (0.2 µm), soaked in alkaline detergent, brushed 5 times each face, rinsed with filtrated water (0.2 µm), and dried with sterile cloth. For group 3-DMC plus hinge inner brushing (n = 5), the forceps were soaked in detergents and brushed as in group 2, including hinge inner brushing (2-mm lumen brush) (Fig. 1). In group 4 (automated cleaning in a washer/disin...
Research Interests:
Research Interests:
Diabetic foot ulcers (DFUs) and diabetic foot infections (DFIs) are associated with reduced patient quality of life, lower-extremity amputation, hospitalization, and high morbidity and mortality. Diverse bacterial communities have been... more
Diabetic foot ulcers (DFUs) and diabetic foot infections (DFIs) are associated with reduced patient quality of life, lower-extremity amputation, hospitalization, and high morbidity and mortality. Diverse bacterial communities have been identified in DFUs/DFIs, playing a significant role in infection prognosis. However, due to the high heterogeneity of bacterial communities colonized in DFUs/DFIs, culture-based methods may not isolate all of the bacterial population or unexpected microorganisms. Recently, high sensitivity and specificity of DNA (metagenomics) and RNA (metatranscriptomics) technologies have addressed limitations of culture-based methods and have taken a step beyond bacterial identification. As a consequence, new advances obtained from DNA- and RNA-based techniques for bacterial identification can improve therapeutic approaches. This review evaluated the current state of play in aetiology of DFUs/DFIs on culture and molecular approaches, and discussed the impact of met...
Research Interests:
Research Interests:
Cleaning is fundamental to infection control. This report demonstrates that a Staphylococcus aureus biofilm is significantly harder to remove than dried planktonic bacteria. A single wipe removed >99.9% (>3Log10) of dried planktonic... more
Cleaning is fundamental to infection control. This report demonstrates that a Staphylococcus aureus biofilm is significantly harder to remove than dried planktonic bacteria. A single wipe removed >99.9% (>3Log10) of dried planktonic bacteria, whereas only 1.48Log10 of biofilm (96.66%) was removed by a standardised wiping process after 50 wipes.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Diabetic foot infections (DFIs) are a major cause of hospitalization and can lead to lower extremity amputation. In this pilot study, we used a multiomics approach to explore the host–microbe complex within DFIs. We observed minimal... more
Diabetic foot infections (DFIs) are a major cause of hospitalization and can lead to lower extremity amputation. In this pilot study, we used a multiomics approach to explore the host–microbe complex within DFIs. We observed minimal differences in the overall microbial composition between PEDIS infection severities, however Staphylococcus aureus and Streptococcus genera were abundant and highly active in most mild to moderate DFIs. Further, we identified the significant enrichment of several virulence factors associated with infection pathogenicity belonging to both Staphylococcus aureus and Streptococcus. In severe DFIs, patients demonstrated a greater microbial diversity and differential gene expression demonstrated the enrichment of multispecies virulence genes suggestive of a complex polymicrobial infection. The host response in patients with severe DFIs was also significantly different as compared to mild to moderate DFIs. This was attributed to the enrichment of host genes ass...
Research Interests:
The normal continuity of skin tissue can be affected by invading pathogens and lead to a series of complicated physiological events. Using an RNA sequencing-based approach, we have captured a metatranscriptomic landscape from diabetic... more
The normal continuity of skin tissue can be affected by invading pathogens and lead to a series of complicated physiological events. Using an RNA sequencing-based approach, we have captured a metatranscriptomic landscape from diabetic foot infections (DFIs). The hierarchical clustering of the top 2,000 genes showed the expression of four main clusters in DFIs (A, B, C, and D). Clusters A and D were enriched in genes mainly involved in the recruitment of inflammatory cells and immune responses and clusters B and C were enriched in genes related to skin cell development and wound healing processes such as extracellular structure organization and blood vessel development. Differential expression analysis showed more than 500 differentially expressed genes (DEGs) between samples with a low number of virulence factors and samples with a high number of virulence factors. Up-regulated and down-regulated genes were mainly involved in adaptive/native immune responses and transport of mature ...
Research Interests:
Research Interests:
Breast implantation either for cosmetic or reconstructive e purposes is one of the most common procedures performed in plastic surgery. Biofilm infection is hypothesised to be involved in the development of both capsular contracture and... more
Breast implantation either for cosmetic or reconstructive e purposes is one of the most common procedures performed in plastic surgery. Biofilm infection is hypothesised to be involved in the development of both capsular contracture and anaplastic large cell lymphoma (ALCL). Capsular contracture is one of the principal reasons for breast revision surgery and is characterised by the tightening and hardening of the capsule surrounding the implant, and ALCL is an indolent lymphoma found only in women with textured implants. We describe the types of breast implants available with regard to their surface characteristics of surface area and roughness and how this might contribute to capsular contracture and/or biofilm formation. The pathogenesis of capsular contracture is thought to be due to biofilm formation on the implant, which results in on-going inflammation. We describe the current research into breast implant associated ALCL and how implant properties may affect its pathogenesis, ...
Research Interests:
Research Interests:
BackgroundPathogens can survive for extended periods when incorporated into biofilm on dry hospital surfaces (ie, dry-surface biofilm, DSB). Bacteria within biofilm are protected from desiccation and have increased tolerance to cleaning... more
BackgroundPathogens can survive for extended periods when incorporated into biofilm on dry hospital surfaces (ie, dry-surface biofilm, DSB). Bacteria within biofilm are protected from desiccation and have increased tolerance to cleaning agents and disinfectants.ObjectiveWe hypothesized that gloved hands of healthcare personnel (HCP) become contaminated with DSB bacteria and hence may transmit bacteria associated with healthcare-associated infections (HAIs).MethodStaphylococcus aureus DSB was grown in vitro on coupons in a bioreactor over 12 days with periodic nutrition interspersed with long periods of dehydration. Each coupon had ~107 DSB bacterial cells. Transmission was tested with nitrile, latex, and surgical gloves by gripping DSB-covered coupons then pressing finger tips onto a sterile horse blood agar surface for up to 19 consecutive touches and counting the number of colony-forming units (CFU) transferred. Coupons were immersed in 5% neutral detergent to simulate cleaning, a...
Research Interests:
Research Interests:
Research Interests:
The finding of a double capsule surrounding breast implants is a recognized complication of breast augmentation surgery. In a recent review, double capsules were identified in 14 of 626 breast implants. 1 We report the detection of... more
The finding of a double capsule surrounding breast implants is a recognized complication of breast augmentation surgery. In a recent review, double capsules were identified in 14 of 626 breast implants. 1 We report the detection of incidental double capsules both in a ...
Research Interests:
Abstract Background Most of the world's bacteria live in biofilms, three-dimensional clusters attached to surfaces.Manyhospital-acquired infections are associated with biofilm infections of implantable medical devices such as... more
Abstract Background Most of the world's bacteria live in biofilms, three-dimensional clusters attached to surfaces.Manyhospital-acquired infections are associated with biofilm infections of implantable medical devices such as orthopaedic prostheses and intravascular catheters. Within biofilms, bacteria are significantly less susceptible to antibiotics and host defences, making biofilm infections difficult to diagnose and treat, and often necessitating removal of the infected implant. Method In this review article we describe the process of biofilm formation, quorum sensing, and biofilm infection of the healthcare environment, surgical instruments and implantable medical devices. Conclusion The inability to treat biofilm-infected devices means that therapies targeting biofilm-specific processes and targeting prevention of biofilm formation are required.
Research Interests:
Research Interests:
Research Interests:
To investigate the effect of negative pressure wound therapy (NPWT) with and without instillation (NPWTi) on in vitro mature biofilm. Mature biofilms of and were grown under shear (130 rpm) on polycarbonate coupons in a CDC biofilm... more
To investigate the effect of negative pressure wound therapy (NPWT) with and without instillation (NPWTi) on in vitro mature biofilm. Mature biofilms of and were grown under shear (130 rpm) on polycarbonate coupons in a CDC biofilm reactor for 3 days. Coupons containing biofilms were placed in a sterile petri dish and sealed using NPWT or NPWTi. Coupons were exposed to treatment for 24 h with NPWT alone or with instillation of: Povidone iodine solution (PVP-I) (10% / equivalent to 1% / available iodine, BETADINE, Mundipharma, Singapore), surfactant based antimicrobial solution with polyhexamethylene biguanide (SBPHMB) (Prontosan, B Braun Medical, Melsungen, Germany), Gentamicin 1 µg/mL (GM) (G1264 Sigma-Aldrich Pty Ltd., Castle Hill, Australia) Rifampicin 24 µg/mL (RF) (R3501 Sigma-Aldrich Pty Ltd., Castle Hill, Australia) and NaCl 0.9% (Baxter, Deerfield, IL, USA). Bacterial cell viability and biofilm architecture pre-and post-treatment were assessed using colony forming units (cfu...
Research Interests:
Research Interests:
Research Interests:
The acquisition of reusable surgical instruments (RSIs) through loaner system is a worldwide phenomenon, particularly in orthopaedic surgeries. Loaner sets contain high-complex design RSIs, which are very difficult to clean, and also... more
The acquisition of reusable surgical instruments (RSIs) through loaner system is a worldwide phenomenon, particularly in orthopaedic surgeries. Loaner sets contain high-complex design RSIs, which are very difficult to clean, and also include single use implants, such as screws, that remain in the surgical tray and are subjected to multiple reprocessing until they are implanted. Inadequate cleaning of SI and various exposures of single-use implants to physical, chemical and biological agents can compromise their quality/safety and promote biofilm formation. The difficulty in cleaning is compounded in middle and low-income countries where automated cleaning infrastructure at sterilizing service units is often unavailable, and thus manual cleaning only is performed. Thus, we aimed to determine the condition of orthopaedic loaned sets when delivered to the hospital, assess the quality of complex-design RSIs reprocessed by manual cleaning, and evaluate the effect of multiple reprocessing...
Research Interests:
Research Interests:
The introduction of texture to the outer shell of breast implants was aimed at increasing tissue incorporation and reducing capsular contracture. It has also been shown that textured surfaces promote a higher growth of bacteria and are... more
The introduction of texture to the outer shell of breast implants was aimed at increasing tissue incorporation and reducing capsular contracture. It has also been shown that textured surfaces promote a higher growth of bacteria and are linked to the development of breast implant-associated anaplastic large cell lymphoma. The authors aimed to measure the surface area and surface roughness of 11 available implants. In addition, the authors aimed to subject these implant shells to an in vitro bacterial attachment assay with four bacterial pathogens (Staphylococcus epidermidis, S. aureus, Pseudomonas aeruginosa, and Ralstonia pickettii) and study the relationship among surface area, surface roughness, and bacterial growth. Surface area measurement showed grouping of implants into high, intermediate, low, and minimal. Surface roughness showed a correlation with surface area. The in vitro assay showed a significant linear relationship between surface area and bacterial attachment/growth. The high surface area/roughness implant texture grew significantly more bacteria at 24 hours, whereas the minimal surface area/roughness implant textures grew significantly fewer bacteria of all types at 24 hours. For implants with intermediate and low surface areas, some species differences were observed, indicating possible affinity of specific bacterial species to surface morphology. Implant shells should be reclassified using surface area/roughness into four categories (high, intermediate, low, and minimal). This classification is superior to the use of descriptive terms such as macrotexture, microtexture, and nanotexture, which are not well correlated with objective measurement and/or functional outcomes.
Research Interests:
Dry surface biofilms (DSB) persist for extended period in hospital, may play significant role in healthcare-associated infections transmission. This study aims to determine if DSB can be transferred from hospital surfaces to healthcare... more
Dry surface biofilms (DSB) persist for extended period in hospital, may play significant role in healthcare-associated infections transmission. This study aims to determine if DSB can be transferred from hospital surfaces to healthcare worker's hands. 12-day Staphylococcus aureus DSB was grown on polycarbonate and glass coupons in CDC bioreactor. 1.8x10 and 8.8x10 bacteria grew on polycarbonate and glass coupons respectively. Transmission was tested by lifting the coupon with forefinger and thumb of ungloved hands to a height of 30 cm then touching horse blood agar (HBA) plates 19 sequential times. Transferred bacterial number was determined by colony forming units. The effect of DSB wetting, on biofilm transfer was tested with 5 seconds 5% neutral detergent treatment. Between 5.5 and 6.6% of the DSB bacteria were transferred to hands with one touch and approximately 20% were then transferred to HBA with one touch giving an overall transfer rate of 1.26% and 1.04% for polycarbon...
Research Interests:
Organisms causing healthcare associated infections can be sourced from the inanimate environment around patients. Residing in a biofilm increases the chances of these organisms persisting in the environment. We aimed to characterise... more
Organisms causing healthcare associated infections can be sourced from the inanimate environment around patients. Residing in a biofilm increases the chances of these organisms persisting in the environment. We aimed to characterise bacterial environmental contamination, genetically and physiologically, and relate this to general intensive care unit (ICU) cleanliness. Cleanliness was determined by adenosine triphosphate (ATP) measurements of 95 high-touch objects. Bacteriological samples were obtained from the same sites (n=95) and from aseptically removed sections (destructive samples, n=20). Bacterial enrichment culture was conducted using tryptone soya broth prior to plating on horse blood agar, MacConkey agar, and screening chromogenic agar for identification of multidrug resistance organism (MDRO). Bacterial load and microbial diversity were determined using quantitative PCR (qPCR) and next generation DNA sequencing respectively. Confocal laser scanning microscopy and scanning ...
Research Interests:
Capsular contracture induced by chronic subclinical infection is a major cause of poor outcomes and reoperation in breast implant surgery. The use of pocket irrigation with antiseptic/antibiotic has been shown to reduce the incidence of... more
Capsular contracture induced by chronic subclinical infection is a major cause of poor outcomes and reoperation in breast implant surgery. The use of pocket irrigation with antiseptic/antibiotic has been shown to reduce the incidence of contracture. A new formulation of hypochlorous acid solution PhaseOne has been proposed as potential agent for irrigation. This study aimed to test the efficacy of hypochlorous acid solution PhaseOne for use in breast pocket irrigation as an alternative to povidone iodine solution Betadine. The efficacy of PhaseOne, a hypochlorous acid formulated wound and skin cleanser, was tested in vitro against planktonic and biofilm Staphylococcus aureus with or without biological soil and in an implant attachment assay. Its activity was compared with Betadine containing 10% povidone iodine. Our findings showed that PhaseOne was unable to eradicate planktonic and/or biofilm S. aureus in the presence of either tryptone soy broth or bovine calf serum (protein soil...
Research Interests:
Research Interests:
Alcohol is frequently inappropriately used on surgical instruments to reduce bacterial contamination, but fixes protein to stainless steel. Here we compare the effect of air drying, prolonged soaking in water, and alcohol treatment on... more
Alcohol is frequently inappropriately used on surgical instruments to reduce bacterial contamination, but fixes protein to stainless steel. Here we compare the effect of air drying, prolonged soaking in water, and alcohol treatment on cleaning difficulty of contaminated forceps. Haltsted-mosquito forceps were contaminated with only Staphylococcus aureus. Instruments were air-dried for 10 (control), 75, or 240 minutes, soaked in water, or air dried then treated with ethanol or isopropanol for 10 seconds. All instruments were prewashed for 15 minutes. Forceps contaminated with blood and S aureus or Pseudomonas aeruginosa were dried and then sprayed or wiped with ethanol, and prewashed. Bacterial viability and soiling were determined by standard plate culture and crystal violet staining, respectively. Soaking or spraying instruments with alcohol significantly reduced viable bacterial numbers, but significantly increased soil attached to forceps, as did air drying. Wiping instruments with alcohol had little effect on bacterial viability, but increased cleaning difficulty. Soaking in water for 75 or 240 minutes increased cleaning difficulty perhaps due to bacterial attachment to forceps. Treating contaminated instruments with alcohol, allowing them to dry, or allowing them to soak in water for prolonged periods increases cleaning difficulty and should be discouraged.
Research Interests:
Serovar Typhimurium of Salmonella enterica is a model organism for studies of pathogenesis that exhibits phage-type variation and variation in host range and virulence, but in a recent study showed no sequence variation in four genes,... more
Serovar Typhimurium of Salmonella enterica is a model organism for studies of pathogenesis that exhibits phage-type variation and variation in host range and virulence, but in a recent study showed no sequence variation in four genes, indicating the clonal nature of this serovar. We determined the relationships of 46 Typhimurium isolates of nine phage types using mutational changes detected either
Research Interests: Genetics, Polymorphism, Phylogeny, Change detection, Computer Model, and 10 moreSalmonella Typhimurium, Molecular Phylogenetics and Evolution, Phylogenetic Tree, Genetic variation, Genome sequence, Host Range, Genetic Markers, Molecular Sequence Data, DNA mutational analysis, and Salmonella enterica
Forty disposable medical shoe covers were briefly exposed to the surgical floor and were found contaminated by a large number of bacteria. This study also demonstrated live bacteria, including pathogens attached to contaminated shoe... more
Forty disposable medical shoe covers were briefly exposed to the surgical floor and were found contaminated by a large number of bacteria. This study also demonstrated live bacteria, including pathogens attached to contaminated shoe covers, can be subsequently transferred to surgical bedsheets. We suggest an infection control policy should be considered to prevent patients returning to their bed with contaminated disposable shoe covers.
Research Interests:
Research Interests:
A recent association between breast implants and the development of anaplastic large-cell lymphoma (BIA-ALCL) has been observed. Both animal and human studies have shown bacterial biofilm infection causes capsular contracture and that a... more
A recent association between breast implants and the development of anaplastic large-cell lymphoma (BIA-ALCL) has been observed. Both animal and human studies have shown bacterial biofilm infection causes capsular contracture and that a higher bacterial load produces chronic immune activation around breast implants. to identify whether bacterial biofilm (a potential trigger of tumorigenesis) is present in BIA-ALCL and if so, to compare the bacterial species profile (microbiome) to non-tumor capsule (NTC) samples from breast implants with contracture. 26 BIA-ALCL samples were analyzed for the presence of biofilm by qPCR, next generation sequencing, fluorescent in situ hybridization (FISH) and scanning electron microscopy (SEM) and compared to 62 NTC specimens. Both the BIA-ALCL and NTC samples yielded high numbers of bacteria (BIA-ALCL mean: 4.7 x 10/mg of tissue vs. capsule mean: 4.9 x 10/mg of tissue). Analysis of the microbiome in BIA-ALCL specimens showed significant differences with species identified in NTC specimens. There was significantly more proportion of Ralstonia spp. present in ALCL specimens compared with NTC specimens (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05). In contrast, significantly more Staphylococcus spp. were found associated with NTC specimens as compared with BIA-ALCL specimens (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). Bacterial biofilm was visualized both on scanning electron microscopy and fluorescent in situ hybridization (FISH). This novel finding of bacterial biofilm and a distinct microbiome in BIA-ALCL samples points to a possible infectious contributing etiology. Breast implants are widely used in both reconstructive and aesthetic surgery and strategies to reduce their contamination should be more widely studied and practiced.
Research Interests:
The mucoactive effects of hypertonic saline should promote exacerbation resolution in people with cystic fibrosis (CF). To determine the effects of hypertonic saline inhalation during hospitalisation for exacerbation of CF on length of... more
The mucoactive effects of hypertonic saline should promote exacerbation resolution in people with cystic fibrosis (CF). To determine the effects of hypertonic saline inhalation during hospitalisation for exacerbation of CF on length of stay, lung function, symptoms, oxygenation, exercise tolerance, quality of life, bacterial load and time to next hospitalisation. 132 adults with an exacerbation of CF were randomised to inhale three nebulised doses a day of either 4 mL 7% saline or a taste-masked control of 0.12% saline, throughout the hospital admission. The primary outcome measure was length of hospital stay. All participants tolerated their allocated saline solution. There was no significant difference in length of stay, which was 12 days in the hypertonic saline group and 13 days in controls, with a mean between-group difference (MD) of 1 day (95% CI 0 to 2). The likelihood of regaining pre-exacerbation FEV1 by discharge was significantly higher in the hypertonic saline group (75...
Research Interests:
Fluorescent amplified fragment length polymorphism (AFLP) was applied to 46 Salmonella enterica serovar Typhimurium isolates of Australian origin comprising nine phage types, by using the restriction enzymes MseI and EcoRI and all 16... more
Fluorescent amplified fragment length polymorphism (AFLP) was applied to 46 Salmonella enterica serovar Typhimurium isolates of Australian origin comprising nine phage types, by using the restriction enzymes MseI and EcoRI and all 16 possible MseI +1-EcoRI +1 primer pair combinations. AFLP in the present study showed a very good discrimination power with a Simpson index of diversity of 0.98, and 35 different AFLP patterns were observed in the 46 isolates. AFLP grouped most serovar Typhimurium isolates by phage type and enabled differentiation of phage types. Furthermore, 84 phage-type-specific polymorphic AFLP fragments, for which presence or absence correlated with phage type (including 25 with one exception to phage type specificity) were observed in the 46 strains studied. Eighteen phage-type-specific AFLP fragments were cloned and sequenced. Fifteen are of known genes or have a homologue in the databases. Three sequences are plasmid related, eight are phage related, and four rel...
Research Interests:
Sialic acid, a key component of both human milk oligosaccharides and neural tissues, may be a conditional nutrient during periods of rapid brain growth. We tested the hypothesis that variations in the sialic acid content of a formula milk... more
Sialic acid, a key component of both human milk oligosaccharides and neural tissues, may be a conditional nutrient during periods of rapid brain growth. We tested the hypothesis that variations in the sialic acid content of a formula milk would influence early learning behavior and gene expression of enzymes involved in sialic acid metabolism in piglets. Piglets (n = 54) were allocated to 1 of 4 groups fed sow milk replacer supplemented with increasing amounts of sialic acid as casein glycomacropeptide for 35 d. Learning performance and memory were assessed with the use of easy and difficult visual cues in an 8-arm radial maze. Brain ganglioside and sialoprotein concentrations and mRNA expression of 2 learning-associated genes (ST8SIA4 and GNE) were measured. In both tests, the supplemented groups learned in significantly fewer trials than did the control group, with a dose-response relation for the difficult task (P = 0.018) but not the easy task. In the hippocampus, significant do...
Research Interests:
The UDP-N-acetylglucosamine-2-epimerase/N-acetylmannosamine kinase (Gne) gene encodes a key bifunctional enzyme important in initiating and regulating sialic acid (Sia) synthesis. Sia is commonly expressed as a terminal (non-reducing)... more
The UDP-N-acetylglucosamine-2-epimerase/N-acetylmannosamine kinase (Gne) gene encodes a key bifunctional enzyme important in initiating and regulating sialic acid (Sia) synthesis. Sia is commonly expressed as a terminal (non-reducing) sugar residue on oligosaccharide side chains on cell surface glycoconjugates where it mediates many carbohydrate receptor interactions, particularly in the neural and immune systems. The myriad of functions include nerve cell transmission, memory formation,cell-cell adhesion and communication, and lymphocyte extravasation. Sia is also a major component of human milk oligosaccharides where its level has been correlated with enhanced cognitive function and memory. There is no information, however, if early dietary Sia supplementation that increases the intracellular levels of Sia, may regulate Gne gene expression in developing piglets. To study this possible regulation, we cloned and sequenced a 4.3 kb of pig Gne cDNA (4326 nt), including 2169-nucleotide...
Research Interests:
Research Interests:
Earlier reports suggested that Pseudomonas aeruginosa frequent epidemic clones circulating in cystic fibrosis (CF) centres had increased virulence. However, recent data show no consistent associations with virulence, and suggest... more
Earlier reports suggested that Pseudomonas aeruginosa frequent epidemic clones circulating in cystic fibrosis (CF) centres had increased virulence. However, recent data show no consistent associations with virulence, and suggest attenuation of virulence in chronic infection. Changes to infection control programmes in relation to frequent epidemic clones should be based on their frequency, virulence across all age groups and mode of acquisition. The Australian epidemic strain-1 (AES-1) (or the Melbourne epidemic strain) and AES-2 are common in CF clinics in mainland eastern Australia, but not in the environment. Both have shown increased virulence, but there are no data specifically in adults. This study examines the frequency and virulence of P. aeruginosa frequent epidemic clones in the adult CF clinic at Royal Prince Alfred Hospital, Sydney, Australia. Two hundred and fifty-eight P. aeruginosa isolates from 112 participants were genotyped by pulsed field gel electrophoresis. Ninety-eight patients were followed up for 1 year and associations sought between infection with a frequent epidemic clone, clinical outcome and antibiotic resistance. Four frequent P. aeruginosa epidemic clones (AES-1, AES-2, S-1, S-2) affected almost 50% of participants. AES-1 predominated (38%). AES-1, AES-2 and S-1 were associated with increased exacerbations and hospital-admission days. AES-1 showed increased resistance to aminoglycosides and ticarcillin-clavulanate. This study supports the potential threat of frequent P. aeruginosa epidemic clones in adult CF populations.