Amit Ranjan, PhD

  • Associate Research Scientist in the Center for Infection and Immunity
Profile Headshot


Dr. Ranjan is a clinical microbiologist focused to explore the dynamic role of microbiome and host in different status of health and diseases by employing cutting-edge muti-omics strategy to gain system level understanding of the pathobiology, physiology, and cellular communications in complex chronic unexplained diseases such as Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and Gulf war Illness (GWI). He has also developed an enhanced capture-based culture independent technique to identify all human associated bacterial pathogens and its antimicrobial resistance determinants. Dr. Ranjan is interested in deciphering the roles of gut-bacterial communities in colorectal cancers and fiber induced metagenomics and metabolomics changes and its impact on host health.

Academic Appointments

  • Associate Research Scientist in the Center for Infection and Immunity

Credentials & Experience

Committees, Societies, Councils

Member, American Society of Microbiology (ASM)

International Society of Infectious Diseases

Editorial Boards


Review editor: Frontiers in Microbiology, Frontiers in Medicine, Frontiers in Public Health

Ad hoc reviewer: The American Journal of Tropical Medicine and Hygiene (AJTMH), Emerging Microbes & Infections, Gut-pathogens, Journal of Applied Microbiology, Molecular Epidemiology and Evolutionary Genetics of Infectious Diseases (MEEGID), Plos One, Scientific Reports, Virulence,


Honors & Awards

2024: Calderone Junior Faculty Award

2012-17: Junior Research and Senior Research Fellow, Indian Council of Medical Research (ICMR)

2016: ERASMUS+, Freie University (Berlin)


Research Interests

  • Antimicrobial resistance
  • Chronic disease
  • Epidemiology
  • Infectious Diseases
  • Microbiome

Selected Publications

Kapoor V, Briese T, Ranjan A, Donovan WM, Mansukhani MM, Chowdhary R, Lipkin WI. Validation of the VirCapSeq-VERT system for differential diagnosis, detection, and surveillance of viral infections. J Clin Microbiol. 2024;62(1):e0061223. Epub 2023/12/14. doi: 10.1128/jcm.00612-23. PubMed PMID: 38095845; PMCID: PMC10793283.

Guo C, Che X, Briese T, Ranjan A, Allicock O, Yates RA, Cheng A, March D, Hornig M, Komaroff AL, Levine S, Bateman L, Vernon SD, Klimas NG, Montoya JG, Peterson DL, Lipkin WI, Williams BL. Deficient butyrate producing capacity in the gut microbiome of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome patients is associated with microbial network disturbances and fatigue symptoms. Cell Host & Microbe.

Arif Hussain, Sabiha Shaik, Amit Ranjan, Arya Suresh, Nishat Sarker, Torsten Semmler, Lothar H Wieler, Munirul Alam, Haruo Watanabe, Dipshikha Chakravortty, Niyaz Ahmed. Genomic and functional characterization of poultry Escherichia coli from India revealed diverse extended-spectrum β-lactamase-producing lineages with shared virulence profiles, Frontiers in microbiology 10, 2019.

Arya Suresh, Sabiha Shaik, Ramani Baddam, Amit Ranjan, Shamsul Qumar, Savita Jadhav, Torsten Semmler, Irfan A Ghazi, Lothar H Wieler, Niyaz Ahmed. Evolutionary Dynamics Based on Comparative Genomics of Pathogenic Escherichia coli Lineages Harboring Polyketide Synthase (pks) Island mBio, e03634-20, 2021

Martinna Bertolini, Amit Ranjan, Angela Thompson, Patricia I Diaz, Takanori Sobue, Kendra Maas, Anna Dongari-Bagtzoglou. Candida albicans induces mucosal bacterial dysbiosis that promotes invasive infection, PLoS pathogens 15 (4), e1007717

A Ranjan, A Dongari-Bagtzoglou Tipping the Balance: C. albicans Adaptation in Polymicrobial Environments Journal of Fungi 4 (3), 112, 2018.

Arya Suresh, Amit Ranjan, Savita Jadhav, Arif Hussain, Sabiha Shaik, Munirul Alam, Ramani Baddam, Lothar H Wieler, Niyaz Ahmed. Molecular genetic and functional analysis of pks-harboring, extra-intestinal pathogenic Escherichia coli from India, Frontiers in microbiology 9, 2018.

Amit Ranjan, Julia Scholz, Katharina Schaufler, Torsten Semmler, Lothar H. Wieler, Christa Ewers, Derek J. Pickard, Peter Schierack, Niyaz Ahmed, Karsten Tedin and Sebastian Guenther. Influence of ESBL plasmid carriage on in vitro bacterial competition fitness and serum resistance in E. coli strains of sequence types ST131 and ST648 Gut pathogens 10 (1), 24; 2018.

Ranjan A, Sabiha Shaik, Nishant Nandanwar, Arif Hussain, Sumeet K Tiwari, Torsten Semmler, Savita Jadhav, Lothar H Wieler, Munirul Alam, Rita R Colwell and Niyaz Ahmed. Comparative Genomics of Escherichia coli isolated from Skin and Soft tissue and other Extra-intestinal Infections. mBio doi: 10.1128/mBio.01070-1715 August 2017 mBio vol. 8 no. 4 e01070-17.

Sabiha Shaik, Amit Ranjan, Sumeet Tiwari, Arif Hussain, Nishant Nandanwar, Narender Kumar, Savita Jadhav, Torsten Semmler, Ramani Baddam, Mohammad Aminul Islam, Munirul Alam, Lothar H. Wieler , Haruo Watanabe and Niyaz Ahmed. Comparative genomic analysis of globally dominant ST131 clone with other epidemiologically successful extra-intestinal pathogenic Escherichia coli (ExPEC) lineages. mBio doi: 10.1128/mBio.01596-1724 October 2017 mBio vol. 8 no. 5 e01596-17

Ranjan A, Shaik S, Mondal A, Nandanwar N, Hussain A, Semmler T, et al. Molecular epidemiology and genome dynamics of New Delhi metallo­beta­lactamase (NDM) producing extraintestinal pathogenic E. coli (ExPEC) strains from India. Antimicrobial agents and chemotherapy AAC01345­16. 60 (11), 6795-6805

Ranjan A, Shaik S, Hussain A, Nandanwar N, Semmler T, Jadhav S, Wieler LH, Ahmed N. Genomic and Functional Portrait of a Highly Virulent, CTX-M-15-Producing H30-Rx Subclone of Escherichia coli Sequence Type 131. Antimicrob Agents Chemother. 2015 Oct;59(10):6087-95.

Arif Hussain, Sabiha Shaik, Amit Ranjan, Nishant Nandanwar, Sumeet K. Tiwari, Mohammad Majid, Ramani Baddam, Insaf A. Qureshi, Torsten Semmler, Lothar H. Wieler, Mohammad A. Islam, Dipshikha Chakravortty and Niyaz Ahmed. Risk of zoonotic transmission of antimicrobial resistant Escherichia coli from commercial broiler and free-range retail chicken in India Frontiers in microbiology doi: 10.3389/fmicb.2017.02120

Hussain A, Ranjan A, Nandanwar N, Babbar A, Jadhav S, Ahmed N. Genotypic and phenotypic profiles of Escherichia coli isolates belonging to clinical sequence type 131 (ST131), clinical non-ST131, and fecal non-ST131 lineages from India. Antimicrob Agents Chemother. 2014 Dec;58(12):7240-9. doi: 10.1128/AAC.03320-14.