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'. CONCLUSION: 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.
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'. CONCLUSION: 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: B K Sundhindra; S Vijayakumar; Krishnan A Kutty; S R Tholpadi; R S Rajan; Elizabeth Mathai; Didier M Raoult; T Jacob John Journal: Natl Med J India Date: 2004 Jan-Feb Impact factor: 0.537
Authors: Carol S Devamani; Wolf-Peter Schmidt; Koya Ariyoshi; Arumugam Anitha; Saravanan Kalaimani; John A J Prakash Journal: Am J Trop Med Hyg Date: 2020-05-21 Impact factor: 2.345
Authors: Matthew T Robinson; Jaruwan Satjanadumrong; Tom Hughes; John Stenos; Stuart D Blacksell Journal: Epidemiol Infect Date: 2019-10-07 Impact factor: 2.451