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PatentMarchesi JR, McDonald JAK, Mullish BH, 2019,
Clostridioides difficile
The invention relates to Clostridioides difficile, and in particular to compounds, polypeptides and mixtures for the treatment of C. difficile infections. The invention also relates to nucleic acids, vectors comprising these nucleic acids and microorganisms for the treatment of C. difficile infections, and to methods of identifying and matching faecal microbiota transplant (FMT) donors to FMT recipients.
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Journal articleLim C, Ha KP, Clarke R, et al., 2019,
Identification of a potent small-molecule inhibitor of bacterial DNA repair that potentiates quinolone antibiotic activity in methicillin-resistant Staphylococcus aureus
, Bioorganic and Medicinal Chemistry, Vol: 27, Pages: 1-7, ISSN: 0968-0896The global emergence of antibiotic resistance is one of the most serious challenges facing modern medicine. There is an urgent need for validation of new drug targets and the development of small molecules with novel mechanisms of action. We therefore sought to inhibit bacterial DNA repair mediated by the AddAB/RecBCD protein complexes as a means to sensitize bacteria to DNA damage caused by the host immune system or quinolone antibiotics. A rational, hypothesis-driven compound optimization identified IMP-1700 as a cell-active, nanomolar potency compound. IMP-1700 sensitized multidrug-resistant Staphylococcus aureus to the fluoroquinolone antibiotic ciprofloxacin, where resistance results from a point mutation in the fluoroquinolone target, DNA gyrase. Cellular reporter assays indicated IMP-1700 inhibited the bacterial SOS-response to DNA damage, and compound-functionalized Sepharose successfully pulled-down the AddAB repair complex. This work provides validation of bacterial DNA repair as a novel therapeutic target and delivers IMP-1700 as a tool molecule and starting point for therapeutic development to address the pressing challenge of antibiotic resistance.
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Journal articleFurniss C, Dortet L, Bolland W, et al., 2019,
Detection of colistin resistance in Escherichia coli using the MALDI Biotyper Sirius mass spectrometry system
, Journal of Clinical Microbiology, Vol: 57, Pages: 1-7, ISSN: 0095-1137Polymyxin antibiotics are a last-line treatment for multidrug-resistant Gram-negative bacteria. However, the emergence of colistin resistance, including the spread of mobile mcr genes, necessitates the development of improved diagnostics for the detection of colistin-resistant organisms in hospital settings. The recently developed MALDIxin test enables detection of colistin resistance by MALDI-TOF mass spectrometry in less than 15 minutes, but is not optimized for the mass spectrometers commonly found in clinical microbiology laboratories. In this study, we adapted the MALDIxin test for the MALDI Biotyper Sirius MALDI-TOF mass spectrometry system (Bruker Daltonics). We optimized the sample preparation protocol using a set of 6 MCR-expressing Escherichia coli clones and validated the assay with a collection of 40 E. coli clinical isolates, including 19 confirmed MCR producers, 12 colistin-resistant isolates which tested negative for commonly encountered mcr genes (i.e. likely chromosomally-resistant isolates) and 9 polymyxin-susceptible isolates. We calculated Polymyxin resistance ratio (PRR) values from the acquired spectra; a PRR value of zero, indicating polymyxin susceptibility, was obtained for all colistin-susceptible E. coli isolates, whereas positive PRR values, indicating resistance to polymyxins, were obtained for all resistant strains independent of the genetic basis of resistance. Thus, we report a preliminary feasibility study showing that an optimized version of the MALDIxin test, adapted for the routine MALDI Biotyper Sirius, provides an unbiased, fast, reliable, cost-effective and high-throughput way of detecting colistin resistance in clinical E. coli isolates.
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Journal articleSumrall ET, Shen Y, Keller AP, et al., 2019,
Phage resistance at the cost of virulence: Listeria monocytogenes serovar 4b requires galactosylated teichoic acids for InlB-mediated invasion
, PLoS Pathogens, Vol: 15, ISSN: 1553-7366The intracellular pathogen Listeria monocytogenes is distinguished by its ability to invade and replicate within mammalian cells. Remarkably, of the 15 serovars within the genus, strains belonging to serovar 4b cause the majority of listeriosis clinical cases and outbreaks. The Listeria O-antigens are defined by subtle structural differences amongst the peptidoglycan-associated wall-teichoic acids (WTAs), and their specific glycosylation patterns. Here, we outline the genetic determinants required for WTA decoration in serovar 4b L. monocytogenes, and demonstrate the exact nature of the 4b-specific antigen. We show that challenge by bacteriophages selects for surviving clones that feature mutations in genes involved in teichoic acid glycosylation, leading to a loss of galactose from both wall teichoic acid and lipoteichoic acid molecules, and a switch from serovar 4b to 4d. Surprisingly, loss of this galactose decoration not only prevents phage adsorption, but leads to a complete loss of surface-associated Internalin B (InlB),the inability to form actin tails, and a virulence attenuation in vivo. We show that InlB specifically recognizes and attaches to galactosylated teichoic acid polymers, and is secreted upon loss of this modification, leading to a drastically reduced cellular invasiveness. Consequently, these phage-insensitive bacteria are unable to interact with cMet and gC1q-R host cell receptors, which normally trigger cellular uptake upon interaction with InlB. Collectively, we provide detailed mechanistic insight into the dual role of a surface antigen crucial for both phage adsorption and cellular invasiveness, demonstrating a trade-off between phage resistance and virulence in this opportunistic pathogen.
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Journal articleCain AK, Nolan LM, Sullivan GJ, et al., 2019,
Complete genome sequence of pseudomonas aeruginosa reference strain PAK
, Microbiology Resource Announcements, Vol: 8, ISSN: 2576-098XWe report the complete genome of Pseudomonas aeruginosa strain PAK, a strain which has been instrumental in the study of a range of P. aeruginosa virulence and pathogenesis factors and has been used for over 50 years as a laboratory reference strain.
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Journal articleSinganayagam A, Snelgrove RJ, 2019,
Less burn, more fat: electronic cigarettes and pulmonary lipid homeostasis
, JOURNAL OF CLINICAL INVESTIGATION, Vol: 129, Pages: 4077-4079, ISSN: 0021-9738- Author Web Link
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- Citations: 4
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Conference paperSmith WD, Cameron SJ, Fletcher OL, et al., 2019,
PSEUDOMONAS AERUGINOSA METABOLOME DIFFERENCES BETWEEN CF AND NON-CF BRONCHIECTASIS DETECTED USING DIRECT-FROM-SAMPLE MASS SPECTROMETRY
, Pediatric Pulmonology, Publisher: WILEY, Pages: S313-S313, ISSN: 8755-6863 -
Journal articleWood TE, Howard SA, Forster A, et al., 2019,
The Pseudomonas aeruginosa T6SS delivers a periplasmic toxin that disrupts bacterial cell morphology
, Cell Reports, Vol: 29, Pages: 187-201.e7, ISSN: 2211-1247The type VI secretion system (T6SS) is crucialin interbacterial competition and is avirulence determinant ofmany Gram-negative bacteria. Several T6SS effectorsarecovalently fused to secreted T6SS structural components such asthe VgrG spike for delivery into target cells.In Pseudomonas aeruginosa, theVgrG2b effector waspreviously proposedto mediatebacterial internalisation into eukaryotic cells. In this work, wefind that the VgrG2b C-terminal domain(VgrG2bC-ter) elicits toxicity in the bacterial periplasm, counteracted by a cognate immunity protein.We resolve thestructure of VgrG2bC-ter and confirm it is a member ofthezinc-metallopeptidasefamily of enzymes. We show that this effector causesmembrane blebbing atmidcell, whichsuggests a distincttype of T6SS-mediated growthinhibition through interference with cell division, mimicking the impact of β-lactam antibiotics. Ourstudyintroduces a further effector family to the T6SS arsenaland demonstrates that VgrG2b can target both prokaryotic and eukaryotic cells.
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Journal articleRudramurthy SM, Colley T, Abdolrasouli A, et al., 2019,
In vitro antifungal activity of a novel topical triazole PC945 against emerging yeast Candida auris
, Journal of Antimicrobial Chemotherapy, Vol: 74, Pages: 2943-2949, ISSN: 0305-7453ObjectivesManagement of Candida auris infection is difficult as this yeast exhibits resistance to different classes of antifungals, necessitating the development of new antifungals. The aim of this study was to investigate the susceptibility of C. auris to a novel antifungal triazole, PC945, optimized for topical delivery.MethodsA collection of 50 clinical isolates was obtained from a tertiary care hospital in North India. Nine isolates from the UK, 10 from a CDC panel (USA) and 3 from the CBS-KNAW culture collection (Japanese and South Korean isolates) were also obtained. MICs (azole endpoint) of PC945 and other triazoles were determined in accordance with CLSI M27 (third edition). Quality control strains were included [Candida parapsilosis (ATCC 22019) and Candida krusei (ATCC 6258)].ResultsSeventy-four percent of isolates tested showed reduced susceptibility to fluconazole (≥64 mg/L). PC945 (geometric mean MIC = 0.058 mg/L) was 7.4-fold and 1.5-fold more potent than voriconazole and posaconazole, respectively (both P < 0.01). PC945 MIC values correlated with those of voriconazole or posaconazole, and only three isolates were found to be cross-resistant between PC945 and other azoles. ERG11 sequence analysis revealed several mutations, but no correlation could be established with the MIC of PC945. Tentative epidemiological cut-off values (ECOFFs) evaluated by CLSI’s ECOFF Finder (at 99%) with 24 h reading of MICs were 1, 4 and 1 mg/L for PC945, voriconazole and posaconazole, respectively. MIC values for quality control strains of all triazoles were in the normal ranges.ConclusionsPC945 was found to be a more potent inhibitor than posaconazole, voriconazole and fluconazole of C. auris isolates collected globally, warranting further laboratory and clinical evaluations.
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Journal articleWang Z, Zhao S, Jiang S, et al., 2019,
Resonance assignments of N-terminal receiver domain of sigma factor S regulator RssB from Escherichia coli
, BIOMOLECULAR NMR ASSIGNMENTS, Vol: 13, Pages: 333-337, ISSN: 1874-2718- Author Web Link
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- Citations: 1
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