title: Reply to Zelyas and Robinson.
authors.affiliation: Medical Microbiology, Department of Laboratory Medicine, Royal Infirmary of Edinburgh.
authors.forename: Naomi J
authors.initials: NJ
authors.lastname: Gadsby
authors.affiliation: Medical Microbiology, Department of Laboratory Medicine, Royal Infirmary of Edinburgh College of Medicine and Veterinary Medicine, University of Edinburgh.
authors.forename: Clark D
authors.initials: CD
authors.lastname: Russell
authors.affiliation: Medical Microbiology, Department of Laboratory Medicine, Royal Infirmary of Edinburgh.
authors.forename: Martin P
authors.initials: MP
authors.lastname: McHugh
authors.affiliation: Medical Microbiology, Department of Laboratory Medicine, Royal Infirmary of Edinburgh.
authors.forename: Harriet
authors.initials: H
authors.lastname: Mark
authors.affiliation: Department of Anaesthesia, University of Cambridge.
authors.forename: Andrew
authors.initials: A
authors.lastname: Conway Morris
authors.affiliation: Medical Microbiology, Department of Laboratory Medicine, Royal Infirmary of Edinburgh.
authors.forename: Ian F
authors.initials: IF
authors.lastname: Laurenson
authors.affiliation: Respiratory Medicine, Royal Infirmary of Edinburgh, United Kingdom.
authors.forename: Adam T
authors.initials: AT
authors.lastname: Hill
authors.affiliation: Medical Microbiology, Department of Laboratory Medicine, Royal Infirmary of Edinburgh.
authors.forename: Kate E
authors.initials: KE
authors.lastname: Templeton