Senior Lecturer in Microbiology
Programme Leader for the Masters programme in Clinical Microbiology
State Registered Clinical Scientist
Department of Life Sciences
School of Health and Life Sciences
T: +44(0)141 331 8092
F: +44(0)141 331 3208
Current areas of focus
Staphylococcus aureus infections: The ability of S. aureus isolates to grow attached to surfaces in biofilms contributes to the difficulties encountered in the management of staphylococcal infections. These can form on almost any abiotic or biological surface, ranging from metal and plastic to animal tissue and are believed to be involved in approximately 65% of all infections. Infections caused by bacterial biofilms are inherently difficult to eradicate as sessile cells within the biofilm display 10-1000 times reduced susceptibility towards antimicrobials than equivalent populations of free-floating planktonic cells. Once biofilms have formed on these surfaces, therapeutic interventions only rarely achieve clinical cure and device removal is often required, usually involving surgery. The formation of staphylococcal biofilms on contact lenses is an area of current research being undertaken in association with Dr Sven Jonuscheit.
Exposure of bacterial cells to various external stresses, including sub-optimal levels of antimicrobials, may lead to modulated gene expression and either impaired or enhanced the expression of bacterial virulence factors. Exposure of cells within biofilms to sub-lethal levels of various antimicrobials may lead to further tissue pathology and is currently an area under investigation in collaboration with Prof Curtis Gemmell.
Components of the staphylococcal cell wall, including peptidoglycan and lipoteichoic acid, are released from cells during infection. It is believed that these bacterial products may induce a potent local immune response during staphylococcal infections and is the focus of a collaborative study with Dr Patricia Martin.
Healthcare-related infections: Meticillin-resistant S. aureus (MRSA) and glycopeptide-resistant enterococci (GRE) are leading healthcare-associated pathogens responsible for significant levels of morbidity and mortality. Since early 2012 Health Boards have been required to screen all patients in high risk specialties for MRSA carriage. Following screening any patients found to be colonised with MRSA are to be decolonised by using nasal mupirocin cream. However, decolonisation of patients following recommended guidelines is not always successful. On-going studies, in collaboration with Dr Lesley Price, Health Protection Scotland and the MRSA Reference Laboratory, are investigating the efficacy of current decolonisation therapies, including mupirocin, in addition to novel alternative agents.
The enterococci are a leading cause of nosocomial infection. The two medically important species are Enterococcus faecalis and E. faecium, though most infections are caused by E. faecalis. Typical infections caused by these commensals of the intestines include urinary and biliary tract infections, abdominal wound infection, intravascular-catheter-related bloodstream infections, endocarditis and other nosocomial infections. Compared to other bacterial pathogens associated with these types of infection, the virulence mechanisms employed by these organisms are poorly understood. Current studies, in collaboration with Dr Jon Sandoe (Consultant Microbiologist Leeds General Infirmary), are investigating the virulence determinants of the enterococci, with an emphasis on the mechanisms that underlie biofilm formation, strategies to effectively treat infections associated with this mode of growth and the investigation of antibiotic induced stress in bacterial cells and the impact this may have on therapy.
Selected recent publications
Busby S-A, Robb A, Lang S, Takeuchi Y, Vesely P, Scobie L. Antibiotic susceptibility and resistance of Staphylococcus aureus isolated from fresh porcineskin xenografts: Risk to recipients with thermal injury. Burns. (2014) 40;288-294.
Smith K, Gemmell CG, Lang S. Telavancin shows superior activity to vancomycin with multidrug resistant Staphylococcus aureus in a range of in vitro biofilm models. European Journal of Clinical Microbiology and infectious Disease (2013) 32(10):1327-1332.
Donnelly S, English G, de Zwart-Storm E, Lang S, van Steensel MA, Martin PE. Differential susceptibility of Cx26 mutations associated with epidermal dysplasias to peptidoglycan derived from Staphylococcus aureus and Staphylococcus epidermidis. Experimental Dermatology (2012) 21, 592–598.
Teles C, Smith A, Lang S. Antibiotic modulation of the plasminogen binding ability of viridians group streptococci. Antimicrobial Agents and Chemotherapy (2012) 56(1):458-63.
Rajendran R, Mowat E, McCulloch E, Lappin DF, Jones B, Lang S, Majithiya JB, Warn P, Williams C, Ramage G. Azole resistance of Aspergillus fumigatus biofilms is partly associated with efflux pump activity. Antimicrobial Agents and Chemotherapy (2011) 55(5):2092-7.
Teles C, Smith A, Ramage G, Lang S. Identification of clinically relevant viridans group streptococci by phenotypic and genotypic analysis. European Journal of Clinical Microbiology and infectious Disease (2011) 30:243-250.
Teles C, Smith A, Ramage G, Lang S. The role of streptococcal plasmin(ogen) binding in infective endocarditis. European Journal of Clinical Microbiology and infectious Disease (2011) 30:127-129.
Mowat E, Rajendran R, Williams C, Jones B, Lang S, Ramage G. Pseudomonas aeruginosa and their small diffusible extracellular molecules inhibit Aspergillus fumigatus biofilm formation. FEMS microbiology letters (2010) 313(2):96-102.
Robertson J, Lang S, Lambert PA, Martin PE. Peptidoglycan derived from S. epidermidis induces Connexin43 hemichannel activity with consequences on the innate immune response in endothelial cells. Biochemical Journal (2010) 25;432(1):133-43.
Desbois A, Lang S, Gemmell C, Coote, P. Surface disinfection properties of the combination of an antimicrobial peptide, ranalexin, with an endopeptidase, lysostaphin, against methicillin-resistant Staphylococcus aureus (MRSA). Journal of Applied Microbiology (2010) 108(2): 23-730.
Smith K, Gould KA, Ramage G, Gemmell CG, Hinds J, Lang S. The influence of tigecycline on the expression of virulence factors in biofilm associated cells of methicillin resistant Staphylococcus aureus. Antimicrobial Agents and Chemotherapy (2010)54(1): 380-387.
Smith K, Perez A, Ramage G, Gemmell CG, Lang S. A comparison of biofilm-associated cell survival following the in vitro exposure of methicillin resistant Staphylococcus aureus biofilms to the antibiotics clindamycin, daptomycin, linezolid, tigecycline and vancomycin. International Journal of Antimicrobial Agents (2009) 33: 374-378. http://dx.doi.org/10.1016/j.ijantimicag.2008.08.029.
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