title: CpG DNA analysis of bacterial STDs.
abstract: BACKGROUND
  Bacterial infections in the genital tract frequently result in morbidity through a variety of inflammation based symptoms. One component of the bacteria that may trigger host inflammatory response is their DNA. CpG motifs in this DNA are known targets for Toll-like receptor 9 (TLR9), which is a pathogen-recognition receptors focusing on CpG DNA. The activation of TLR9 induces the NF-κB inflammatory pathway. This study aims to provide a broad view of the inflammatory potential of CpG DNA motifs in bacteria related to genital diseases: C. trachomatis, E. coli, N. gonorrhoeae, G. vaginalis, H. ducreyi, L. crispatus, L. gasseri, M. hominis, M. genitalium, T. pallidum, and U. urealyticum.
  
  
  METHODS
  Publicly available genomic sequences of the bacterial species and strains have been analyzed in silico to produce a CpG index number. This CpG index number shows the relative inflammatory potential of the genome and has previously been used in a study by Lundberg et al. (2003). Higher CpG index values suggest a strong CpG induced inflammation potential during infection and vice versa.
  
  
  RESULTS
  The highest observed CpG index belongs to G. vaginalis with a value of 26,2, suggesting a strong pro-inflammatory potential when in contact with TLR9. The lowest index belongs to N. gonorrhoeae with a value of -79,5, suggesting a strong immunoinhibitory effect on TLR9 contact. Interestingly, Lactobacilli showed a mean CpG index value of 4,2, suggesting a weak inflammatory potential.
  
  
  CONCLUSIONS
  Our results show varying CpG index values between bacterial species. Comparison of CpG indices with the clinical course of several pathogens shows the CpG index helps clarify the clinical course of infection. However, we found no links between CpG index values and either obligate pathogenicity or facultative pathogenicity through bacterial vaginosis. Lactobacilli showed relatively low CpG indices which do suggest a lower inflammatory potential from these bacteria.
  
  
  CONCLUSIONS
  Our results show varying CpG index values between bacterial species, which may help clarify the clinical course of infection, and may help diagnosis.
authors.affiliation: Laboratory of Immunogenetics, Department of Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, The Netherlands. m.singer@vumc.nl.
authors.forename: Martin
authors.initials: M
authors.lastname: Singer
authors.affiliation: Laboratory of Immunogenetics, Department of Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, The Netherlands. d.dewaaij@vumc.nl.
authors.forename: Dewi J
authors.initials: DJ
authors.lastname: de Waaij
authors.affiliation: Laboratory of Immunogenetics, Department of Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, The Netherlands. samorretravel@yahoo.co.uk.|Institute of Public Health Genomics, Department of Genetics and Cell Biology, Research Institutes CAPHRI and GROW, Faculty of Health, Medicine & Life Sciences, University of Maastricht, Maastricht, The Netherlands. samorretravel@yahoo.co.uk.
authors.forename: Servaas A
authors.initials: SA
authors.lastname: Morré
authors.affiliation: Laboratory of Immunogenetics, Department of Medical Microbiology and Infection Control, VU University Medical Center, Amsterdam, The Netherlands. s.ouburg@vumc.nl.
authors.forename: Sander
authors.initials: S
authors.lastname: Ouburg
mesh_terms: D001419:Bacteria / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D001483:Base Sequence; D018899:CpG Islands; D004269:DNA, Bacterial / Q000737:chemistry* / Q000378:metabolism; D030541:Databases, Genetic; D006194:Gardnerella vaginalis / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D016680:Genome, Bacterial; D006801:Humans; D009344:Neisseria gonorrhoeae / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D060737:Reproductive Tract Infections / Q000382:microbiology; D012749:Sexually Transmitted Diseases / Q000382:microbiology*; D015398:Signal Transduction; D051217:Toll-Like Receptor 9 / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; C495371:TLR9 protein, human; D051217:Toll-Like Receptor 9