Microbiology, Immunology & Molecular Genetics

Baseman, Joel B., Ph.D.

Professor Emeritus


Ph. D. Microbiology at the University of Massachusetts, Amherst, Massachusetts


Keywords: Mycoplasma pneumoniae (MPN); Community Acquired Respiratory Distress Syndrome (CARDS)

Research interests:
We study the biology of the atypical pathogenic bacterium, Mycoplasma pneumoniae (MPN), and have related these studies to acute and chronic respiratory diseases in humans and animal models. Our recent discovery of the Community Acquired Respiratory Distress Syndrome (CARDS) toxin of MPN represents the first authentic toxin and virulence determinant found in MPN, as the toxin behaves as a bonafide ADP-ribosylating toxin (like the classical ADP-ribosylating toxins of pertussis and diphtheria) and vacuolating toxin (like VacA of Helicobacter pylori). CARDS TX is a remarkable, one-of-a-kind protein; no other toxin or virulence factor exhibits both ADP ribosylation and vacuolating activities, possesses allergenic properties, and elicits such a distinctive host response, including unique inflammatory pathways and tissue injury. Based upon our clinical and animal model studies and in vitro observations, we have compelling evidence that CARDS TX represents a single molecule tightly responsible for mediating a range of airway diseases, including asthma.

We also examine the sexually transmitted mycoplasma, Mycoplasma genitalium (MGN), and are clarifying MGN virulence determinants that mediate the dynamic interactions between MGN and human target cells, leading to overt clinical disease. Recently, we described the remarkable ability of MGN to exhibit perinuclear and intranuclear localization, suggesting that this pathogen circumvents host defenses and navigates through mammalian cell structures in order to establish and maintain viability and persistence. Recently, we examined the impact of MGN in Chlamydia co-infection models and have observed an exaggerated inflammatory and pathologic host response contributed to MGN.

Currently, I am Director of the NIH-funded SA-AADCRC (San Antonio-Asthma and Allergic Diseases Cooperative Research Center) and have considerable experience as Director of past CRCs and Program Projects and as PI of R01s and T32s and Foundation grants. I held the position of Chair of UTHSCSA Department of Microbiology and Immunology for 33 years and other positions, such as Associate Dean for Research for the UTHSCSA Graduate School of Biomedical Sciences and Director/Teacher of the Ethics in Research Course at UTHSCSA. I have had the opportunity and pleasure to mentor many predoctoral and postdoctoral fellows and collaborate extensively with basic science and clinical investigators.

Awards & Accomplishments

  • Recipient of the UTHSCSA Presidential Distinguished Senior Research Scholar Award
  • Emmy Klieneberger-Nobel Award and Medal for Outstanding Career Research, International Organization for Mycoplasmology, Fukuoka, Japan
  • Elected Fellow, American Association for the Advancement of Science
  • Elected Fellow, American Society for Microbiology
  • Invited Speaker, Second Conference of Asian Organization for Mycoplasmology, Beijing, China (2005)
  • Invited Speaker, American Academy of Allergy, Asthma and Immunology Annual Meeting, Philadelphia, Pennsylvania (2008)
  • Invited Speaker, The Genomics Research Center, Academia Sinica (2010)
  • Invited Speaker, American Thoracic Society International Conference, Post Graduate Course (2007-2011)
  • Invited Speaker, National Trauma Institute, Annual Conference – Advances in Trauma, San Antonio, Texas (2012)
  • Invited Speaker, China University Medical School, Taichung, Taiwan (2015)
  • Invited Speaker, The American Academy of Allergy, Asthma & Immunology Foundation (AAAAI) Annual Meeting, Los Angeles, California (2016)
  • Member,  UTHSCSA Council of Principal Investigators (CPI)


  • American Society for Microbiology
  • American Association for the Advancement of Science
  • Association of Medical School Microbiology and Immunology Chairs
  • International Organization for Mycoplasmology
  • American Association of Medical Colleges GREAT (Graduate Research Education and Training) Group


Complete List of Publications

  • Krishnan, M., T.R. Kannan and J.B. Baseman.  2013.  Mycoplasma pneumoniae CARDS toxin is internalized via clathrin-mediated endocytosis.  PLoS One  8(5):e62706.  PMID: 23667510
  • Wood, P.R., V.L. Hill, M.L. Burks, J.I. Peters, H. Singh, T.R. Kannan, S. Vale, M.P. Cagle, M.P., M.F.R. Principe, J.B. Baseman and E.G. Brooks.  2013.  Mycoplasma pneumoniae in children with acute and refractory asthma. Ann. Allergy Asthma Immunol. 110:328-34. PMID: 23622002
  • Zhang, W. and J.B. Baseman.  2014.  Functional Characterization of Osmotically Inducible Protein C (MG_427) from Mycoplasma genitalium. J. Bacteriol., 196(5):1012-19.  PMID: 24363346
  • Tang, L., Z. Yang, H. Zhang, Z. Zhou, B. Arulanandam, J. Baseman, and G. Zhong. 2014.  Induction of protective immunity against Chlamydia muridarum intracervical infection in DBA/1j mice.  Vaccine.  32:1407-13.  PMID:24188757
  • Kannan, T.R., M. Krishnan, R. K. Ramasamy, A. Becker, O.N. Pakhomova, P.J. Hart, and J.B. Baseman.  2014.  Functional mapping of community acquired respiratory distress syndrome (CARDS) toxin of Mycoplasma pneumoniae defines regions with ADP-ribosyltransferase, vacuolating, and receptor-binding activities.  Mol. Microbiol. 93(3):568-81.  PMID: 24948331
  • Medina, J., J.J. Coalson, E.G. Brooks, C.J. LeSaux, V.T. Winter, A. Chaparro, M.F.R. Principe, L. Solis, T.R. Kannan, J.B. Baseman and P. Dube.  2014.  Mycoplasma pneumoniae CARDS toxin exacerbates ovalbumin-induced asthma-like inflammation in BALB/c mice.  PLoS One 9(7):e102613. PMID: 25058417
  • Somarajan, S.R, F. Al-Asadi, K. Ramasamy, L. Pandranki, J.B. Baseman and T.R. Kannan.  2014.  Annexin A2 mediates Mycoplasma pneumoniae CARDS toxin binding to eukaryotic cells.MBio 5(4):e01497-1514. PMID: 25139904
  • Bose, S., J.A. Segovia, S.R. Somarajan, T-H Chang, Kannan, T.R. and J.B. Baseman.  2014.  ADP-ribosylation of NLRP3 by Mycoplasma pneumoniae CARDS toxin regulates inflammasome activity.  MBio 23;5(6): e02186-14. PMID: 25538194
  • Becker, A., T.R. Kannan, A.B. Taylor, O.N. Pakhomova, Y. Zhang, J. Jiang, S.R. Somarajan, A. Galaleldeen, S.P. Holloway, B. Demeler, J.B. Baseman and P.J. Hart.  2015. Structure of CARDS toxin, a unique ADP-ribosylating and vacuolating cytolating cytotoxin from Mycoplasma pneumoniae.  Proc. Nat. Acad. Sci.,112(16):5165-70; PMID:25848012
  • Tsai, S.; Segovia, J.A.; Chang, T.; Shil, N.K.; Pokharel, S.M.; Kannan, T.R.; Baseman, J.B.; Defrene J.; Pagé, N.; Cesaro, A.; Tessier, P.A. and Bose, S. Regulation of TLR3 activation by S100A9. J. Immunol. ol.1500378, published online 18 September 2015, J. Immun.