Lynne Turnbull

• PhD
• Principal Scientist at Leica Microsystems

Recalcitrant chronic infections of implanted medical devices are often linked to the presence of biofilms. The prevention and treatment of medical device-associated infections is a major source of antibiotic use and driver of antimicrobial resistance globally. Lowering the incidence of infection in patients that receive implanted medical devices co...

Peroxisomes are recognized as significant platforms for the activation of antiviral innate immunity where stimulation of the key adapter molecule mitochondrial antiviral signaling protein (MAVS) within the RIG-I like receptor (RLR) pathway culminates in the up-regulation of hundreds of ISGs, some of which drive augmentation of multiple innate sensi...

Bacterial biofilms are composed of aggregates of cells encased within a matrix of extracellular polymeric substances (EPS). One key EPS component is extracellular DNA (eDNA), which acts as a ‘glue’, facilitating cell–cell and cell–substratum interactions. We have previously demonstrated that eDNA is produced in Pseudomonas aeruginosa biofilms via e...

Bacterial biofilms are comprised of aggregates of cells encased within a matrix of extracellular polymeric substances (EPS). One key EPS component is extracellular DNA (eDNA), which acts as a ‘glue’, facilitating cell-cell and cell-substratum interactions. We have previously demonstrated that eDNA is produced in Pseudomonas aeruginosa biofilms via...

Natural transformation is a mechanism that enables competent bacteria to acquire naked, exogenous DNA from the environment. It is a key process that facilitates the dissemination of antibiotic resistance and virulence determinants throughout bacterial populations. Pseudomonas aeruginosa is an opportunistic Gram-negative pathogen that produces large...

Twitching motility-mediated biofilm expansion occurs via coordinated, multi-cellular collective behaviour to allow bacteria to actively expand across surfaces. Type-IV pili (T4P) are cell-associated virulence factors which mediate twitching motility via rounds of extension, surface attachment and retraction. The Chp chemosensory system is thought t...

Background: Progesterone Receptor Membrane Component 1 (PGRMC1) is expressed in many cancer cells, where it is associated with detrimental patient outcomes. It contains phosphorylated tyrosines which evolutionarily preceded deuterostome gastrulation and tissue differentiation mechanisms. Results: We demonstrate that manipulating PGRMC1 phosphory...

Background: Progesterone Receptor Membrane Component 1 (PGRMC1) is expressed in many cancer cells, where it is associated with detrimental patient outcomes. It contains phosphorylated tyrosines which evolutionarily preceded deuterostome gastrulation and tissue differentiation mechanisms. Results: We demonstrate that manipulating PGRMC1 phosphorylat...

Background: Progesterone Receptor Membrane Component 1 (PGRMC1) is expressed in many cancer cells, where it is associated with detrimental patient outcomes. It contains phosphorylated tyrosines which evolutionarily preceded deuterostome gastrulation and tissue differentiation mechanisms. Results: We demonstrate that manipulating PGRMC1 phosphorylat...

Background: Progesterone Receptor Membrane Component 1 (PGRMC1) is expressed in many cancer cells, where it is associated with detrimental patient outcomes. It contains phosphorylated tyrosines which evolutionarily preceded deuterostome gastrulation and tissue differentiation mechanisms. Results: We demonstrate that manipulating PGRMC1 phosphorylat...

Chronic wound treatment is becoming increasingly difficult and costly, further exacerbated when wounds become infected. Bacterial biofilms cause most chronic wound infections and are notoriously resistant to antibiotic treatments. The need for new approaches to combat polymicrobial biofilms in chronic wounds combined with the growing antimicrobial...

Natural transformation is a mechanism that enables competent bacteria to acquire naked, exogenous DNA from the environment. It is a key process that facilitates the dissemination of antibiotic resistance and virulence determinants throughout bacterial populations. Pseudomonas aeruginosa is an opportunistic Gram-negative pathogen that produces large...

Twitching motility-mediated biofilm expansion occurs via coordinated, multi-cellular collective behaviour to allow bacteria to actively expand across surfaces. Type-IV pili (T4P) are cell-associated virulence factors which mediate this expansion via rounds of extension, surface attachment and retraction. The Chp chemosensory system is thought to re...

Progesterone Receptor Membrane Component 1 (PGRMC1) is expressed in many cancer cells, where it is associated with detrimental patient outcomes. It contains phosphorylated tyrosines which evolutionarily preceded deuterostome gastrulation and tissue differentiation mechanisms. Here, we demonstrate that manipulating PGRMC1 phosphorylation status in M...

Pandoraea species have been isolated from diverse environmental samples and are emerging important respiratory pathogens, particularly in people with cystic fibrosis (CF). In the present study, two bacterial isolates initially recovered from consecutive sputum samples collected from a CF patient and identified as Pandoraea pnomenusa underwent a pol...

Abstract Enzootic pneumonia incurs major economic losses to pork production globally. The primary pathogen and causative agent, Mycoplasma hyopneumoniae, colonises ciliated epithelium and disrupts mucociliary function predisposing the upper respiratory tract to secondary pathogens. Alleviation of disease is reliant on antibiotics, vaccination, and...

Mycoplasma hyopneumoniae is an economically devastating, globally disseminated pathogen that can maintain a chronic infectious state within its host, swine. Here, we depict the events underpinning M. hyopneumoniae biofilm formation on an abiotic surface and demonstrate for the first time, biofilms forming on porcine epithelial cell monolayers and i...

Mycoplasma hyopneumoniae, an agriculturally important porcine pathogen, disrupts the mucociliary escalator causing ciliostasis, loss of cilial function, and epithelial cell death within the porcine lung. Losses to swine production due to growth rate retardation and reduced feed conversion efficiency are severe, and antibiotics are used heavily to c...

Chronic wound infections are a major burden to both society and the health care industry. Bacterial biofilms are the major cause of chronic wound infections and are notoriously recalcitrant to treatments with antibiotics, making them difficult to eradicate. Thus, new approaches are required to combat biofilms in chronic wounds. One possible approac...

Analysis of honey-antibiotic interactions using MacSynergy II. Overall synergy and antagonism values determined by plotting with 95% confidence intervals, based on the Bonferroni adjustment 97% (Prichard and Shipman, 1990).

Advancements in optical microscopy technology have allowed huge progression in the ability to understand protein structure and dynamics in live bacterial cells using fluorescence microscopy. Paramount to high-quality microscopy is good sample preparation to avoid bacterial cell movement that can result in motion blur during image acquisition. Here,...

Bacterial outer membrane vesicles (OMVs) are extracellular sacs containing biologically active products, such as proteins, cell wall components and toxins. OMVs are reported to contain DNA, however, little is known about the nature of this DNA, nor whether it can be transported into host cells. Our work demonstrates that chromosomal DNA is packaged...

Clostridium sordellii is an often-lethal bacterium causing human and animal disease. Crucial to the infectious cycle of C. sordellii is its ability to produce spores, which can germinate into toxin-producing vegetative bacteria under favorable conditions. However, structural details of the C. sordellii spore are lacking. Here, we used a range of el...

DNA-binding proteins are central regulators of chromosome organization; however, in genome-reduced bacteria their diversity is largely diminished. Whether the chromosomes of such bacteria adopt defined three-dimensional structures remains unexplored. Here we combine Hi-C and super-resolution microscopy to determine the structure of the Mycoplasma p...

Supplementary Figures, Supplementary Tables and Supplementary Methods

3D model of the first cluster of M. pneumoniae genome models.

3D reconstruction of a M. pneumoniae chromosome from DAPI staining and 3D-SIM imaging.

3D reconstruction of a M. pneumoniae cell from EM imaging.

: List of DNA-binding proteins with their average copy numbers per basepair of DNA for M. pneumoniae, E. Coli and B. subtilis.

We provide a folder containing all the data and scripts used to reproduce the analysis of identification of chromosomal interactions domains (CIDs). 1. Matrices_for_TADbit: contains the input raw and normalized matrices of the sum of the five HpaII replicates described in Figure 4a, of the HpaII with novobiocin described in Figure 5a, and of each o...

Twitching motility is a mode of surface translocation that is mediated by the extension and retraction of type IV pili and which, depending on the conditions, enables migration of individual cells or can manifest as a complex multicellular collective behavior that leads to biofilm expansion. When twitching motility occurs at the interface of an abi...

Schematic of surface micro-fabrication method. A clean silicon wafer (A) was coated in negative NLOF 2020 photoresist (B). Prebake of the photoresist at 110°C for 1 min was performed to enhance adhesion to the substrate and minimize mask contamination (C). A brightfield chrome on glass photomask was then aligned in the desired position over the pho...

P. aeruginosa cells are preferentially confined to the micro-fabricated furrows during interstitial biofilm expansion. Time-lapse phase-contrast microscopy was performed across 2000 s with a capture rate of one frame every 2 s to observe P. aeruginosa interstitial biofilm expansion across PDMS with micro-fabricated furrows with dimensions of 5 μm (...

Pr. vulgaris cells are preferentially confined to the micro-fabricated furrows during interstitial biofilm expansion. Time-lapse phase-contrast microscopy was performed across 2000 s with a capture rate of one frame every 2 s to observe Pr. vulgaris interstitial biofilm expansion across PDMS with micro-fabricated furrows with dimensions of 5 μm (wi...

Micro-fabricated furrows disrupt Pr. vulgaris swarm front during interstitial biofilm expansion. Time-lapse phase-contrast microscopy was performed across 500 s with a capture rate of one frame every 2 s to observe Pr. vulgaris interstitial biofilm expansion across PDMS with micro-fabricated furrows with dimensions of 5 μm (width) × 1 μm (depth) ×...

Surface translocation by the soil bacterium Myxococcus xanthus is a complex multicellular phenomenon that entails two motility systems. However, the mechanisms by which the activities of individual cells are coordinated to manifest this collective behaviour are currently unclear. Here we have developed a novel assay that enables detailed microscopi...

Many bacteria produce extracellular and surface-associated components such as membrane vesicles (MVs), extracellular DNA and moonlighting cytosolic proteins for which the biogenesis and export pathways are not fully understood. Here we show that the explosive cell lysis of a sub-population of cells accounts for the liberation of cytosolic content i...

Supplementary Figures 1-7, Supplementary Tables 1-2 and Supplementary References

Explosive cell lysis occurs in the absence of fluorescent stains and fluorescence microscopy. A P. aeruginosa PAK interstitial biofilm was imaged using phase contrast microscopy (Olympus IX71) in the absence of input fluorescence excitation energy, antibiotics or fluorescent stains in the culture media. The 2 time-series show single rod cells rapid...

Explosive cell lysis releases eDNA. A P. aeruginosa PAK interstitial biofilm cultured on media containing the cell impermeant DNA stain TOTO-1 (green) was imaged using phase contrast and widefield fluorescence microscopy (Nikon Ti). An individual rod cell rapidly transitions to a round-shaped cell and subsequently explodes releasing eDNA. Time is s...

Long-lasting round cells are malleable. A P. aeruginosa PAK interstitial biofilm cultured on media containing the membrane stain FM1-43FX was imaged using widefield fluorescence microscopy (DeltaVision OMX conventional mode). An individual round cell (upper right) is shown over a period of approximately six minutes as it as it is pushed by surround...

Exploding bacteria express pyocin genes. An interstitial biofilm of P. aeruginosa PAO1 containing the Phol-eGFP promoter reporter pM0614-G was imaged using phase contrast (left panel) and fluorescence (right panel) microscopy (Nikon Ti). The cell that rounds up and explodes expresses GFP.

Round cells are viable until explosive cell lysis. A P. aeruginosa PAK interstitial biofilm cultured on media containing the cell impermeant DNA stain EtHD-2 was imaged using phase contrast (left panel) and fluorescence (right panel) microscopy (Nikon Ti). All cells, including two round cells, exclude EtHD-2 indicating they have intact membranes. O...

Explosive cell lysis occurs during early stages of submerged biofilm development. Time series of the initial stages of P. aeruginosa PAO1 biofilm development 1 h after inoculation showing attachment of a rod cell, its transition to round cell morphotype and subsequent explosion releasing eDNA (TOTO-1, green). Time in min (top right), scale bar 5 μm...

Dynamic lipid particles in interstitial biofilms. An interstitial biofilm of P. aeruginosa PAK cultured on media containing the lipid stain FM1-43FX was imaged using widefield fluorescence microscopy (DeltaVision OMX conventional mode). Dynamic lipid particles can be observed bouncing amongst the migrating cells of the biofilm. Time is shown in min...

MVs in P. aeruginosa interstitial biofilms. A P. aeruginosa PAK biofilm cultured on media containing the lipid stain FM1-43FX was imaged using f3D-SIM (DeltaVision OMX Blaze). MVs of varying diameters can be seen surrounding the cells of the biofilm and are very mobile. Chains of MVs can be seen stretching between cells. MVs are also observed squas...

List of differentially abundant RNAs in MVs against planktonic cells.

MVs are formed through curling of membrane fragments produced by explosive cell lysis. A P. aeruginosa PAK biofilm cultured on media containing the lipid stain FM1-43FX was imaged using f3D-SIM (DeltaVision OMX Blaze). A single rod cell transitions to a round-shaped cell and explodes (left panel). A magnified view of the boxed area (right panel) sh...

Explosive cell lysis produces MVs. A P. aeruginosa PAK biofilm cultured on media containing the lipid stain FM1-43FX was imaged using f3D-SIM (DeltaVision OMX Blaze). A single rod cell transitions to a round-shaped cell and then subsequently explodes. MVs are observed immediately following the explosion and are not observed to bleb from the cell pr...

Antimicrobial resistance remains a serious global issue, with an increasing prevalence of multi-drug resistant bacteria appearing throughout the biosphere. Evidence of resistance towards our last-line-of-defense antibiotics is also developing, painting a grim outlook for future treatment outcomes. Antimicrobial peptides offer a promising therapeuti...

Pseudomonas aeruginosa is an opportunistic pathogen that exploits damaged epithelia to cause infection. Type IV pili (tfp) are polarly located filamentous structures which are the major adhesins for attachment of P. aeruginosa to epithelial cells. The extension and retraction of tfp powers a mode of surface translocation termed twitching motility t...

Ferlins are a family of transmembrane-anchored vesicle fusion proteins uniquely characterized by 5–7 tandem cytoplasmic C2 domains, Ca2+-regulated phospholipid-binding domains that regulate vesicle fusion in the synaptotagmin family. In humans, dysferlin mutations cause limb-girdle muscular dystrophy (LGMD2B) due to defective Ca2+-dependent, vesicl...

Infection with the human liver fluke Opisthorchis viverrini induces cancer of the bile ducts, cholangiocarcinoma (CCA). Injury from feeding activities of this parasite within the human biliary tree causes extensive lesions, wounds that undergo protracted cycles of healing, and re-injury over years of chronic infection. We show that O. viverrini sec...

Liver fluke infection caused by Opisthorchis viverrini remains a major public health problem in many parts of Asia including Thailand, Lao PDR, Vietnam and Cambodia, where there is a strikingly high incidence of cholangiocarcinoma (CCA - hepatic cancer of the bile duct epithelium). Among other factors, uptake of O. viverrini excretory/secretory pro...

Background: Throughout Asia, there is an unprecedented link between cholangiocarcinoma and infection with the liver fluke Opisthorchis viverrini. Multiple processes, including chronic inflammation and secretion of parasite proteins into the biliary epithelium, drive infection toward cancer. Until now, the mechanism and effects of parasite protein...

Dichelobacter nodosus is the essential causative agent of footrot in sheep and type IV fimbriae-mediated twitching motility has been shown to be essential for virulence. We have identified a two-component signal transduction system (TwmSR) that shows similarity to chemosensory systems from other bacteria. Insertional inactivation of the gene encodi...

Skin infections caused by antibiotic resistant Staphylococcus aureus are a significant health problem worldwide; often associated with high treatment cost and mortality rate. Complex natural products like New Zealand (NZ) manuka honey have been revisited and studied extensively as an alternative to antibiotics due to their potent broad-spectrum ant...

The self-organisation of collective behaviours often manifests as dramatic patterns of emergent large-scale order. This is true for relatively "simple" entities such as microbial communities and robot "swarms," through to more complex self-organised systems such as those displayed by social insects, migrating herds, and many human activities. The p...

Tubulin is a major component of the eukaryotic cytoskeleton, controlling cell shape, structure and dynamics, whereas its bacterial homologue FtsZ establishes the cytokinetic ring that constricts during cell division1, 2. How such different roles of tubulin and FtsZ evolved is unknown. Studying Archaea may provide clues as these organisms share char...

Mycoplasma hyopneumoniae, the etiological agent of porcine enzootic pneumonia, regulates the presentation of proteins on its cell surface via endoproteolysis, including those of the cilial adhesin P123 (MHP_0194). These proteolytic cleavage events create functional adhesins that bind to proteoglycans and glycoproteins on the surface of ciliated and...

Imaging of biological samples using fluorescence microscopy has advanced substantially with new technologies to overcome the resolution barrier of the diffraction of light allowing super-resolution of live samples. There are currently three main types of super-resolution techniques - stimulated emission depletion (STED), single-molecule localizatio...

Nontypeable Hemophilus influenzae (NTHi) is a Gram-negative bacterial pathogen that causes chronic biofilm infections of the ears and airways. The biofilm matrix provides structural integrity to the biofilm and protects biofilm cells from antibiotic exposure by reducing penetration of antimicrobial compounds into the biofilm. Extracellular DNA (eDN...

Twitching motility is a mode of solid surface translocation that occurs under humid conditions on semisolid or solid surfaces, is dependent on the presence of retractile type IV pili and is independent of the presence of a flagellum. Surface translocation via twitching motility is powered by the extension and retraction of type IV pili and can mani...

Chronic wounds are a major global health problem. Their management is difficult and costly, and the development of antibiotic resistance by both planktonic and biofilm-associated bacteria necessitates the use of alternative wound treatments. Honey is now being revisited as an alternative treatment due to its broad-spectrum antibacterial activity an...

The Gram-negative human pathogen Pseudomonas aeruginosa tolerates high concentrations of β-lactam antibiotics. Despite inhibiting the growth of the organism, these cell wall-targeting drugs exhibit remarkably little bactericidal activity. However, the mechanisms underlying β-lactam tolerance are currently unclear. Here, we show that P. aeruginosa u...

Bacterial biofilms are complex multicellular communities that are often associated with the emergence of large-scale patterns across the biofilm. How bacteria self-organize to form these structured communities is an area of active research. We have recently determined that the emergence of an intricate network of trails that forms during the twitch...

Pseudomonas aeruginosa is the leading cause of morbidity and mortality in cystic fibrosis (CF). This study examines the role of organism-specific factors in the pathogenesis of very early P. aeruginosa infection in the CF airway. A total of 168 longitudinally collected P. aeruginosa isolates from children diagnosed with CF following newborn screeni...

We have described the presence of cell membrane-associated κ free immunoglobulin light chains (FLC) on the surface of myeloma cells. Notably, the anti-κFLC mAb, MDX-1097, is being assessed in clinical trials as a therapy for κ light chain isotype multiple myeloma. Despite the clinical potential of anti-FLC mAbs, there have been limited studies on c...

Described is the antibiotic activity of a marine natural product. Psammaplysin F (1) inhibited the growth of four Gram-positive strains by >80% at 50μM, and the amine at position C-20 is responsible for the observed antibacterial activity. When tested against two strains of methicillin resistant Staphylococcus aureus (MRSA), the minimum inhibitory...

Described is the antimicrobial activity of alkaloid psammaplysins, which are marine natural products. A compound library collected from natural sources in Australia was screened for antimicrobial activity against a panel of Gram-positive and Gram-negative bacteria. Two natural products psammaplysins F (1) and H (2), inhibited the growth of differen...

The mechanistic details of the pathogenesis of Chlamydia, an obligate intracellular pathogen of global importance, have eluded scientists due to the scarcity of traditional molecular genetic tools to investigate this organism. Here we report a chemical biology strategy that has uncovered the first essential protease for this organism. Identificatio...

Twitching motility-mediated biofilm expansion is a complex, multicellular behavior that enables the active colonization of surfaces by many species of bacteria. In this study we have explored the emergence of intricate network patterns of interconnected trails that form in actively expanding biofilms of Pseudomonas aeruginosa. We have used high-res...

In Plasmodium falciparum, the deadliest form of human malaria, the nuclear periphery has drawn much attention due to its role as a sub-nuclear compartment involved in virulence gene expression. Recent data have implicated components of the nuclear envelope in regulating gene expression in several eukaryotes. Special attention has been given to nucl...

Cellular imaging remains one of the most important techniques in life science research based in part on the notion that "seeing is believing." For a variety of practical reasons including types of probes available and access of probes to their intracellular targets, imaging is currently most often performed on specimens that have been fixed and lab...

Bacterial aminopeptidases play important roles in pathogenesis by providing a source of amino acids from exogenous proteins, destroying host immunological effector peptides and executing posttranslational modification of bacterial and host proteins. We show that MHJ_0125 from the swine respiratory pathogen Mycoplasma hyopneumoniae represents a new...

Live cell microscopy of VACV B5-YFP-induced actin nucleation. HeLa cells were infected with B5R-YFP (green), transfected with pE/L Lifeact-mRFP (red) and imaged for 80 seconds at 6–9 hours post infection. A virus particle is seen colocalising with F-actin tail of approximately 3–4 µm. See Figure 3D for still frames and representative scale bar. (MO...