Molecular detection and analysis of spotted fever group Rickettsia in patients with fever and rash at a tertiary care centre in Tamil Nadu, India

• Published in: Pathogens and global health Vol. 106; no. 1; pp. 40 - 45
• Main Authors: Prakash, John Antony Jude, Sohan Lal, T, Rosemol, Varghese, Verghese, Valsan Philip, Pulimood, Susanne A, Reller, Megan, Dumler, John Stephen
• Format: Journal Article
• Language: English
• Published: London Taylor & Francis 01.03.2012; Maney; Maney Publishing
• Subjects: Bacterial diseases; Bacterial Outer Membrane Proteins - genetics; Bacterial Typing Techniques - methods; Biological and medical sciences; Biopsy; Child; Child, Preschool; Dermatology; DNA, Bacterial - analysis; Fever - microbiology; Fever with rash; General aspects; Human bacterial diseases; Humans; Infant; Infectious diseases; Medical sciences; Nested PCR; ompA gene; Original; Phylogeny; Polymerase Chain Reaction - methods; Prospective Studies; Rickettsia; Rickettsia - classification; Rickettsia - genetics; Rickettsia - isolation & purification; Rickettsia Infections - diagnosis; Rickettsia Infections - microbiology; Rickettsial diseases; Skin - microbiology; Skin - pathology; Skin biopsy; Skin Diseases, Bacterial - diagnosis; Skin Diseases, Bacterial - microbiology; Skin involvement in other diseases. Miscellaneous. General aspects; Spotted fever group (SFG) rickettsia; Tropical bacterial diseases; Asia; Tamil Nadu; India; Human; Skin disease; Rickettsialosis; Boutonneuse fever; Dermatitis; Infection; Rickettsiales; Rickettsial infection; Bacteriosis; Bacteria; Tropical medicine; Rickettsieae; Rickettsia; Rickettsiaceae
• ISSN: 2047-7724; 2047-7732
• DOI: 10.1179/2047773212Y.0000000001

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.