title: Low Concentrations of Nitric Oxide Modulate Streptococcus pneumoniae Biofilm Metabolism and Antibiotic Tolerance.
abstract: Streptococcus pneumoniaeis one of the key pathogens responsible for otitis media (OM), the most common infection in children and the largest cause of childhood antibiotic prescription. Novel therapeutic strategies that reduce the overall antibiotic consumption due to OM are required because, although widespread pneumococcal conjugate immunization has controlled invasive pneumococcal disease, overall OM incidence has not decreased. Biofilm formation represents an important phenotype contributing to the antibiotic tolerance and persistence ofS. pneumoniaein chronic or recurrent OM. We investigated the treatment of pneumococcal biofilms with nitric oxide (NO), an endogenous signaling molecule and therapeutic agent that has been demonstrated to trigger biofilm dispersal in other bacterial species. We hypothesized that addition of low concentrations of NO to pneumococcal biofilms would improve antibiotic efficacy and that higher concentrations exert direct antibacterial effects. Unlike in many other bacterial species, low concentrations of NO did not result inS. pneumoniaebiofilm dispersal. Instead, treatment of bothin vitrobiofilms andex vivoadenoid tissue samples (a reservoir forS. pneumoniaebiofilms) with low concentrations of NO enhanced pneumococcal killing when combined with amoxicillin-clavulanic acid, an antibiotic commonly used to treat chronic OM. Quantitative proteomic analysis using iTRAQ (isobaric tag for relative and absolute quantitation) identified 13 proteins that were differentially expressed following low-concentration NO treatment, 85% of which function in metabolism or translation. Treatment with low-concentration NO, therefore, appears to modulate pneumococcal metabolism and may represent a novel therapeutic approach to reduce antibiotic tolerance in pneumococcal biofilms.
authors: Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom Southampton NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
authors: Raymond N
authors: RN
authors: Allan
authors: Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom.
authors: Samantha
authors: S
authors: Morgan
authors: Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom.
authors: Sanjita
authors: S
authors: Brito-Mutunayagam
authors: Centre for Biological Sciences, University of Southampton, Southampton, United Kingdom Centre for Proteomic Research, Institute for Life Sciences, University of Southampton, Southampton, United Kingdom.
authors: Paul
authors: P
authors: Skipp
authors: Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom Southampton NIHR Respiratory Biomedical Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
authors: Martin
authors: M
authors: Feelisch
authors: Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom.
authors: Stephen M
authors: SM
authors: Hayes
authors: University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
authors: William
authors: W
authors: Hellier
authors: Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom Southampton NIHR Respiratory Biomedical Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
authors: Stuart C
authors: SC
authors: Clarke
authors: Centre for Biological Sciences, University of Southampton, Southampton, United Kingdom Department of Microbial Infection and Immunity, Centre for Microbial Interface Biology, College of Medicine, The Ohio State University, Columbus, Ohio, USA.
authors: Paul
authors: P
authors: Stoodley
authors: University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
authors: Andrea
authors: A
authors: Burgess
authors: University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
authors: Hasnaa
authors: H
authors: Ismail-Koch
authors: Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom Southampton NIHR Respiratory Biomedical Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
authors: Rami J
authors: RJ
authors: Salib
authors: Centre for Biological Sciences, University of Southampton, Southampton, United Kingdom Southampton NIHR Respiratory Biomedical Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
authors: Jeremy S
authors: JS
authors: Webb
authors: Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom Southampton NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom Southampton NIHR Respiratory Biomedical Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom s.faust@soton.ac.uk.
authors: Saul N
authors: SN
authors: Faust
authors: Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom Southampton NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom Department of Microbial Infection and Immunity, Centre for Microbial Interface Biology, College of Medicine, The Ohio State University, Columbus, Ohio, USA.
authors: Luanne
authors: L
authors: Hall-Stoodley
mesh_terms: D000234:Adenoids / Q000187:drug effects / Q000382:microbiology; D019980:Amoxicillin-Potassium Clavulanate Combination / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial / Q000187:drug effects; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D006801:Humans; D006834:Hydrazines / Q000737:chemistry / Q000494:pharmacology; D009566:Nitrates / Q000737:chemistry / Q000494:pharmacology; D009569:Nitric Oxide / Q000737:chemistry / Q000494:pharmacology*; D020030:Nitric Oxide Donors / Q000737:chemistry / Q000494:pharmacology*; D009599:Nitroprusside / Q000737:chemistry / Q000494:pharmacology; D010033:Otitis Media / Q000188:drug therapy / Q000382:microbiology / Q000473:pathology; D011008:Pneumococcal Infections / Q000188:drug therapy / Q000382:microbiology / Q000473:pathology; D014176:Protein Biosynthesis; D012977:Sodium Nitrite / Q000737:chemistry / Q000494:pharmacology; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D006834:Hydrazines; D009566:Nitrates; D020030:Nitric Oxide Donors; D009599:Nitroprusside; D009569:Nitric Oxide; D019980:Amoxicillin-Potassium Clavulanate Combination; C084012:1,1-diethyl-2-hydroxy-2-nitrosohydrazine; C031618:sodium nitrate; D012977:Sodium Nitrite