Meenakshi Kar: Translational Health Science and Technology Institute, Faridabad, Haryana, India.
Amul Nisheetha: National Centre for Biological Sciences, TIFR, Bengaluru, India.
Anuj Kumar: National Centre for Biological Sciences, TIFR, Bengaluru, India.
Suraj Jagtap: Department of Chemical Engineering, Indian Institute of Science, Bengaluru, India.
Jitendra Shinde: Translational Health Science and Technology Institute, Faridabad, Haryana, India.
Mohit Singla: Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India.
Saranya M: Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, India.
Awadhesh Pandit: National Centre for Biological Sciences, TIFR, Bengaluru, India.
Anmol Chandele: ICGEB-Emory Vaccine Center, ICGEB Campus, New Delhi, India.
Sushil K Kabra: Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India.
Sudhir Krishna: National Centre for Biological Sciences, TIFR, Bengaluru, India.
Rahul Roy: Department of Chemical Engineering, Indian Institute of Science, Bengaluru, India; Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, India; Center for Biosystems Science and Engineering, Indian Institute of Science, Bengaluru, India.
Rakesh Lodha: Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India.
Chitra Pattabiraman: National Institute of Mental Health and Neurosciences, Bengaluru, India.
Guruprasad R Medigeshi: Translational Health Science and Technology Institute, Faridabad, Haryana, India. Electronic address: gmedigeshi@thsti.res.in.
OBJECTIVE: To characterize the in vitro replication fitness, viral diversity, and phylogeny of dengue viruses (DENV) isolated from Indian patients. METHODS: DENV was isolated from whole blood collected from patients by passaging in cell culture. Passage 3 viruses were used for growth kinetics in C6/36 mosquito cells. Parallel efforts also focused on the isolation of DENV RNA from plasma samples of the same patients, which were processed for next-generation sequencing. RESULTS: It was possible to isolate 64 clinical isolates of DENV, mostly DENV-2. Twenty-five of these were further used for growth curve analysis in vitro, which showed a wide range of replication kinetics. The highest viral titers were associated with isolates from patients with dengue with warning signs and severe dengue cases. Full genome sequences of 21 DENV isolates were obtained. Genome analysis mapped the circulating DENV-2 strains to the Cosmopolitan genotype. CONCLUSIONS: The replication kinetics of isolates from patients with mild or severe infection did not differ significantly, but the viral titers varied by two orders of magnitude between the isolates, suggesting differences in replication fitness among the circulating DENV-2.
