title: Molecular detection and analysis of spotted fever group Rickettsia in patients with fever and rash at a tertiary care centre in Tamil Nadu, India.
abstract: BACKGROUND
  Detection of specific targets by PCR is used to confirm a diagnosis of spotted fever, but serological tests are still widely used. In this prospective study, nested PCR was performed on skin biopsy specimens to confirm the diagnosis of spotted fever.
  
  
  METHODS
  In 58 clinically suspected cases of spotted fever, nested PCR, to detect gltA, 17 kDa lipoprotein antigen gene (17 kDa), ompA and ompB, from skin biopsy of the rash was performed. Sequencing was carried on amplicons representing the four targets to confirm specificity  of amplification. This was followed by phylogenetic analysis using MEGA version 4.0 software.
  
  
  RESULTS
  The gltA, 17 kDa, ompA, and ompB genes were detected from skin biopsy specimens in 38, 23, 27, and 22 individuals. Sequence analysis revealed that the  gltA, 17 kDa, ompA, and ompB sequences belonged to spotted fever group (SFG) rickettsia. Of the six partial ompA gene sequences, only one was dissimilar to the previously reported 'Candidatus Rickettsia kellyi'.
  
  
  CONCLUSIONS
  Further  evidence indicates that SFG rickettsiae resembling 'Candidatus Rickettsia kellyi' cause fever and rash in southern India. More detailed phylogenetic analysis following isolation of rickettsia in culture is required for providing irrefutable proof for the occurrence of novel  spotted fever rickettsiae in this region.
authors.affiliation: Department of Microbiology, Christian Medical College, Vellore, Tamil Nadu, India. prakjaj@yahoo.com
authors.forename: John Antony Jude
authors.initials: JA
authors.lastname: Prakash
authors.forename: T
authors.initials: T
authors.lastname: Sohan Lal
authors.forename: Varghese
authors.initials: V
authors.lastname: Rosemol
authors.forename: Valsan Philip
authors.initials: VP
authors.lastname: Verghese
authors.forename: Susanne A
authors.initials: SA
authors.lastname: Pulimood
authors.forename: Megan
authors.initials: M
authors.lastname: Reller
authors.forename: John Stephen
authors.initials: JS
authors.lastname: Dumler
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques / Q000379:methods; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000032:analysis; D005334:Fever / Q000382:microbiology*; D006801:Humans; D007223:Infant; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D011446:Prospective Studies; D012281:Rickettsia / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D012282:Rickettsia Infections / Q000175:diagnosis* / Q000382:microbiology; D012867:Skin / Q000382:microbiology / Q000473:pathology; D017192:Skin Diseases, Bacterial / Q000175:diagnosis* / Q000382:microbiology
chemical_list: D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial; C078167:OMPA outer membrane proteins