title: Differentiation of Streptococcus pneumoniae conjunctivitis outbreak isolates by matrix-assisted laser desorption ionization-time of flight mass spectrometry.
abstract: Streptococcus pneumoniae (pneumococcus [Pnc]) is a causative agent of many infectious diseases, including pneumonia, septicemia, otitis media, and conjunctivitis. There have been documented conjunctivitis outbreaks in which nontypeable (NT), nonencapsulated Pnc has been identified as the etiological agent. The use of mass spectrometry to comparatively and differentially analyze protein and peptide profiles of whole-cell microorganisms remains somewhat uncharted. In this report, we discuss a comparative proteomic analysis between NT S. pneumoniae conjunctivitis outbreak strains (cPnc) and other known typeable or NT pneumococcal and streptococcal isolates (including Pnc TIGR4 and R6, Streptococcus oralis, Streptococcus mitis, Streptococcus pseudopneumoniae, and Streptococcus pyogenes) and nonstreptococcal isolates (including Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus) as controls. cPnc cells and controls were grown to mid-log phase, harvested, and subsequently treated with a 10% trifluoroacetic acid-sinapinic acid matrix mixture. Protein and peptide fragments of the whole-cell bacterial isolate-matrix combinations ranging in size from 2 to 14 kDa were evaluated by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Additionally Random Forest analytical tools and dendrogramic representations (Genesis) suggested similarities and clustered the isolates into distinct clonal groups, respectively. Also, a peak list of protein and peptide masses was obtained and compared to a known Pnc protein mass library, in which a peptide common and unique to cPnc isolates was tentatively identified. Information gained from this study will lead to the identification and validation of proteins that are commonly and exclusively expressed in cPnc strains which could potentially be used as a biomarker in the rapid diagnosis of pneumococcal conjunctivitis.
authors: National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
authors: Yulanda M
authors: YM
authors: Williamson
authors: Hercules
authors: H
authors: Moura
authors: Adrian R
authors: AR
authors: Woolfitt
authors: James L
authors: JL
authors: Pirkle
authors: John R
authors: JR
authors: Barr
authors: Maria Da Gloria
authors: Mda G
authors: Carvalho
authors: Edwin P
authors: EP
authors: Ades
authors: George M
authors: GM
authors: Carlone
authors: Jacquelyn S
authors: JS
authors: Sampson
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis; D015373:Bacterial Typing Techniques / Q000379:methods; D016000:Cluster Analysis; D003231:Conjunctivitis / Q000453:epidemiology / Q000382:microbiology*; D004196:Disease Outbreaks; D013293:Enterococcus faecalis / Q000737:chemistry; D004926:Escherichia coli / Q000737:chemistry; D006801:Humans; D017720:Molecular Epidemiology / Q000379:methods; D008970:Molecular Weight; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D020543:Proteome / Q000032:analysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013211:Staphylococcus aureus / Q000737:chemistry; D034361:Streptococcus mitis / Q000737:chemistry; D019533:Streptococcus oralis / Q000737:chemistry; D013296:Streptococcus pneumoniae / Q000737:chemistry* / Q000145:classification* / Q000302:isolation & purification; D013297:Streptococcus pyogenes / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D020543:Proteome