SCOTTISH scientists have moved a step closer to understanding infections after discovering that bacteria use chemical harpoons to hold on tight to body tissue.The global threat of widespread bacterial resistance to antibiotics is one of the greatest challenges facing science and medicine.The new breakthrough discovery of bacterial “chemical harpoons”made by researchers at St Andrews University could pave the way for a new approach to treating bacterial infections by “disarming” bacteria instead of trying to kill them with antibiotics. The research reveals how Streptococcus pyogenes, the cause of many infections ranging from the common strep throat to life-threatening flesh-eating bugs, use chemical harpoons to attach themselves to the body. This tactic is also shared by many other bacteria that infect humans, such as Streptococcus pneumoniae, the most common cause of pneumonia in adults, and Clostridium difficile (C.diff), notorious for causing severe gut infections in hospitalised patients.The study was funded by the Medical Research Council and led by Dr Uli Schwarz-Linek, structural biologist of the Biomedical Sciences Research Complex at St Andrews and Dr Mark Banfield, John Innes Centre in Norwich, in collaboration with Professor Manfred Rohde from the Helmholtz Center for Infection Research, Braunschweig in Germany.