Vivek Sagar
Working as Associate Professor of Public Health Laboratory Sciences (PHLS), at Community Medicine & School of Public Health, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India from 14th Jan 2017.
Following is the list of positions held by me in the past
• Research Fellow in project entitled “Jaivigyan mission mode project on community control of RF/RHD (Epidemiology study)” funded by Indian Council of Medical Research (ICMR), India (October 2000 to March 2002).
• Junior Research Fellow in project entitled “Epidemiological surveillance of Group A Streptococcal infections including pharyngitis and impetigo” funded by Department of Biotechnology, India(Indo-US) (April 2002 to May 2005).
• Senior Research Fellow in project entitled “Streptococcal Inhibitor of Complement Protein: its distribution, isolation and functional characterization from Indian GAS isolates. funded by Indian Council of Medical Research, India (June 2005 to June 2007).
• Senior Research Fellow in ICMR project entitled” emm typing and C- repeat sequencing of emm gene of Group A Streptococcus”.
• Post doctoral scientist at one of the premier institute, Helmholtz Centre for Infection Research, Braunschweig, Germany from July 2007 to Jan 2012 under the guidance of one the renowned scientist in the field of microbiology, Prof. G.S Chhatwal.
• Senior Research Scientist in Indo German project entitled “Validation of PARF peptide from streptococcus as a marker of acute rheumatic fever and rheumatic heart disease” from February 2012 till Feb 2015.
• Worked as Research Associate at School of Public Health Department from March to May 2015.
• Research Scientist D in Indo – Canadian Project entitled “ Urban Rural differences in risk factors and cardiovascular disease : the PURE (Prospective Urban Rural Epidemiology)” from June 2015 till Jan 2017.
Participated in Indo UK project on brucellosis and conducted sero survey for brucellosis in general population of Punjab and also in project on networking of HIV transmission based on gene sequencing.
Research summary and scientific interest
Molecular diversity among Streptococcus pyogenes strains: impact on pathogenesis, treatment and scope of vaccine development !
I started my scientific career of research about 15 years ago when I joined as summer trainee in one of the prestigious Institute of Microbial Technology and worked on project based on marine yeast Debaryomyces hanseni and learnt various basic microbiological and molecular biology techniques. After Masters in Biotechnology, I joined Postgraduate Institute of Medical Education and Research as a Ph.d student and got chance to work in the field of Medical Microbiology. I was actively involved in project related to molecular epidemiology of a human pathogen, Group A Streptococcus (GAS), which is one of the leading cause of high morbidity and mortality, especially in children in developing courtiers like India. GAS is associated with wide spectrum diseases including pharyngitis, tonsillitis, skin infections, sepsis, acute rheumatic fever/rheumatic heart disease and acute glomerulonephritis. Due to high molecular diversity among the GAS strains a successful vaccine could not be developed till date. Therefore initial characterization of GAS strains has become important part of any kind of investigation. So initially, focus of research was on molecular typing of GAS strains on the bases of emm gene sequence (emm typing). About 500 GAS strains identified and emm typed by emm gene sequencing. This data explored the amazing heterogeneity that persist in Indian strains and also explored the difference in the prevalence of types of strains in India (Sagar et al, 2004, Letters in applied microbiology). Interestingly, type emm1 which is most prevalent and invasive strain of western countries was rare in India, instead emm1-2 strain was common in Indian subcontinent. Further study aimed at molecular pathogenesis, where various chromosome encoded and phage encoded virulence factors associated with the strains explored by PCR and microarray analysis. Novel homologue of few of the genes ie streptococcal inhibitor of complement (sic) (Sagar et al, 2008, BMC microbiology), distantly related to sic (Sagar et al, 2007, Journal of bacteriology) and fibronectin binding gene (sfb1-2) were identified, cloned and characterized from emm1-2 strains. Further to explore the mechanism of pathogenesis, capacity of emm1-2 strains to invade HEp-2 cells was also monitored by invasion assays, electron and transmission microscopy. This indicated that emm1-2 strains far more cell invasive in comparison to one of the well known invasive strain, emm1 of western countries (Sagar et al, 2014, Int. J of Med. Micro). Further we have sequenced whole genome of few Indian strains to go deep in to the pathogenic potential of these strains. In order to explore the chances of vaccine development against Group A streptococcus, few genes, which were conserved in GAS strains after microarray analysis selected and cloned. All selected genes encoding cell wall proteins expressed as GST tagged proteins in E coli. The immune response against these proteins in patient sera is monitored using glutathione coated ELISA plates in order to explore immunogenicity of proteins. (Sagar et al, 2012, Clinical and Vaccinology Immunology).
As a Public Health professional I tried to develop interest in other public health problems as well therefore, apart from Streptococcal research, I participated in projects on brucellosis sero-survey (Indo UK), networking of HIV transmission based on gene sequencing (NACO) and also risk factor analysis of cardio vascular diseases (Indo Canadian) and sero-pevalence of dengue in India.
Publications
1. Sagar V, Bakshi DK, Nandi S, Ganguly NK, Kumar R and Chakraborti A. Molecular heterogeneity among North Indian isolates of Group A Streptococcus. Letters in Applied Microbiology (2004)39, 84-88.
2. Sagar V, Kumar R, Ganguly NK, Menon T and Chakraborti A. Distantly related sic (drs) is less divergent then SIC. Journal of Bacteriology (2007) 189, 2933-2935.
3. Sagar V, Kumar R, Ganguly NK and Chakraborti A. Comparative analysis of emm type pattern of Group A Streptococcus throat and skin isolates from India and their association with closely related SIC, a streptococcal virulence factor. BMC microbiology (2008)8, 150.
4. Nandi S, Chakraborti A, Bakshi DK, Sagar V, Kumar R and Ganguly NK. Genotyping of Group A Streptococcus by various molecular methods. Indian Journal of Medical Research (2008), 127,71-77.
5. Kumar R, Vohra H, Chakraborti A, Sharma YP, Bandhopadhya S, Dhanda V, Sagar V, Sharma M, Shah B, Ganguly NK. Epidemiology of Group A Streptococcal Pharyngitis and Impetigo: A Cross Sectional and Follow-up Study in a Rural Community of Northern India. Indian Journal of Medical Research (2009), 130, 765-771.
6. Bakshi DK, Dhanda V, Sagar V, Toor D, Kumar R, Chakraborti A. emm 81, The Predominant Group A Streptococcus from North India in Year 2003 in Context to Adhesion, Invasion and Antimicrobial Susceptibility Pattern. J Bacteriol Parasito (2010).
7. Kumar R, Chakraborti A, Aggarwal AK, Vohra H, Sagar V, Dhanda V, Sharma YP, Majumdar S, Hoe N, Krause RM. Streptococcus pyogenes pharyngitis and impetigo in a rural area of Panchkula district in Haryana, India. Indian Journal of Medical Research (2012),135, 133-136.
8. Bergmann R, Sagar V, Nitsche P and Chhatwal G. S. First detection of trimethoprim resistance determinant dfrG in Streptococcus pyogenes clinical isolates in India. Antimicrobial Agents and Chemotherapy (2012), 56, 5424-5425.
9. Sagar V, Bergmann R, Nerlich A, McMillan D.J, Nitsche P and Chhatwal G. S. Variability in the distribution of genes encoding virulence factors and putative extracellular proteins of Streptococcus pyogenes in India, a region with high streptococcal disease burden, and implication of development of a regional multi-subunit vaccine. Clinical and Vaccine Immunology (2012) 19, 1818-1825.
10. Sharma A, Arya D.K, Sagar V, Bergmann R, Chhatwal G. S and Johri A.K. Identification of potential universal vaccine candidates against group A streptococcus by using high throughput in silico and proteomic approach. Journal of Proteome Research (2013) 12, 336-346.
11. Sagar V*, Nerlich A, Bergmann R, Nitsche P,. McMillan D.J, Geffers R, Hoe N, Kumar R, Nitsche P, Fulde M, Talay S, Rohde M,. Chakraborti A. and Chhatwal G. S. Differences in virulence repertoire and cell invasive potential of group A Streptococcus emm1-2 in comparison to emm1 genotype. International Journal of Medical Microbiology (2014) 304, 685-695.
12. Rastogi M, Sagar V, Kumar R and Chakraborti A. Rheumatic Heart Disease (RHD): Prevention and Control in North India: Addressing the Challenges. Annals in Cardiovascular disease (2016), 1, 1015-1018.
13. Sarkar S, Rastogi M, Choudhary P, Kumar R, Arora P, Sagar V, Sahni IP, Sethi S, Thakur K, Ailawadhi S, Toor D, Chakraborti A. Association of rheumatic fever and rheumatic heart disease with plausible early and late stage disease markers: A comprehensive study. Indian Journal of Medical Research (2017),145, 758-766.
14. Chaudhary P, Kumar R, Sagar V, Sarkar S, Kaur R, Ghosh S, Singh S and Chakraborti A. Assessment of Cpa, Scl1 and Scl2 in clinical Group a streptococcus isolates and patients from north India: A study to evaluate host pathogen interaction. Research in Microbiology (2018) 169, 11-19.
15. Chauhan CK, Lakshmi PVM, Sagar V, Sharma AK, Arora SK and Kumar R. Primary HIV Drug Resistance among recently infected cases of HIV in North-West India. AIDS research and Treatment (2019).
16. Murhekar MV, Kamaraj P, Muthusamy SK, Khan SA, Allam RR, Barde P, Dwibedi B, Kanungo S, Mohan U, Mohanty SS, Roy S, Sagar V, Savargaonkar D et al, Dengue working group. Burden of dengue infection in India, 2017: results from a cross-sectional population based serosurvey. The Lancet Global Health (2019) 7, e1065-e1073.
17. Shupler M, Hystad P, Gustafson P, Rangarajan S, Mushtaha M, Jayachitra, KG, Mony P, Mohan D, Kumar P, Lakshmi PVM, Sagar V et al Household, community, sub-national and country-level predictors of primary cooking fuel switching in nine countries from the PURE Study. Environmental Res letters (2019) 14, 085006.
18. Chauhan CK, Lakshmi PVM, Sagar V, Sharma AK, Arora SK and Kumar R. Using Immunological Markers Identifying Recent HIV Infection in north west India. Indian J of Medical Research, (2020), 152, 227-233.
19. Mangtani P, Berry I, Beauvais W, Holt HR, Kulashri A, Bharti S, Sagar V , Nguipdop-Djomo P, Bedi J, Kaur M, Guitian J, McGiven J, Grover GS , Kumar R. The prevalence and risk factors for human Brucella species infection in a cross-sectional survey of a rural population in Punjab, India. Transactions of The Royal Society of Tropical Med. & Hygiene, (2020), 1-9.
20. Kaur H, Choudhary P, Khanna P, Singh T, Sagar V. Hidden food safety attributes and sensory evaluation of food served under mid-day meal scheme in khamanon block, District Fatehgarh Sahib, Punjab (India). Applied Biological Research (2020), 22, 78-82.
21. Sagar V*, Chkarborti A and Kumar R. Whole genome sequence of Indian group A Streptococcus emm type 1-2 strain isolated from blood sample from North India. Microbiology Resource Announcements(2020, Vol 9, issue 19).
22. Khaiwal R, Sagar V, Vij J, Kulashri A, Kaur M, Padhi, Singh A. Rapid Preparation of Hand Sanitizer using WHO Formulation in Hospitals during Restricted Supply during COVID-19 Pandemic. JPMER, (2020).
23. Murhekar MV, Muthusamy SK, Kamaraj P, Khan SA, Allam RR, Barde P, Dwibedi B, Kanungo S, Mohan U, Mohanty SS, Roy S, Sagar V, Savargaonkar D et al, Dengue working group.Hepatitis-B virus infection in India: Findings from a nationally representative serosurvey, 2017-18. International Journal of Infectious Disease (2020).
24. Shupler M, Hystad P, Birch A, Miller-Lionberg D, Jeronimo M, Arku RE, YLChu, Mushtaha M, Heenan L, Rangarajan S, Seron P, Lakshmi PVM, Sagar V....et all. Household and Personal Air Pollution Exposure Measurements from 120 Communities in 8 Countries: Results from the PURE-AIR Stud. The Lancet Plenary Health, October (2020).
25. Muthusamy SK, Kamaraj P, Khan SA, Allam RR, Barde P, Dwibedi B, Kanungo S, Mohan U, Mohanty SS, Roy S, Sagar V, Savargaonkar D et al Seroprevalence of chikungunya virus infection in India, 2017: a cross-sectional population-based serosurvey. Lancet Microbe 2021.
26. Kaur G, Gupta M, Aggarwal A, Sagar V*. Diagnosis of COVID-19:An evolution from hospital based to point of care testing. J of Community Medicine and Public Health 2021.
27. Sagar V*, Kaur G, Sharma A, Nadda A, Aggarwal A. Exploratory Sero prevalence of SARS-CoV-2 (Covid -19) among health care professionals in Department of Community Medicine & School of Public Health (PGIMER, Chandigarh) J of Community Medicine and Public Health 2021.
28. Murhekar MV, Kamaraj P, Muthusamy SK, Khan SA, Allam RR, Barde P, Dwibedi B, Kanungo S, Mohan U, Mohanty SS, Roy S, Sagar V, Savargaonkar D et al, Dengue working group. Immunity against diphtheria among children aged 5–17 years in India, 2017–18: a cross-sectional, population-based serosurvey. The Lancet Infectious Diseases 2021.
Manuscripts under preparation/communicated
29. Johri A, Sharma A, Arya DK, Sanduja P, Dua M, Rohde M, Chhatwal GS, Sagar V. Cytoplasmic proteome analysis of Group A Streptococci of Indian origin (manuscript submitted).
30. Iyer V, Sagar V, Toor D, Lyngdoh V, Nogrum G, Kapoor M, Chakraborti A. Prevalence of Group A Streptococcus emm types in India: Current scope of Vaccines. (Communicated to Journal of Biological Sceinces)