Jeongmin Song
Assistant Professor

Jeongmin Song




Department of Microbiology & Immunology
C5-183, Veterinary Medicine Center
College of Veterinary Medicine
Cornell University
Ithaca, NY 14853


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Department Profile


Jeongmin Song received a BS in Microbiology from Hannam University, Daejeon, Korea in 1998, an MS in Microbiology from Yonsei University, Seoul, Korea in 2000, and a PhD in Molecular Genetics & Microbiology from Duke University, Durham, NC in 2008.  She was a postdoctoral fellow in the laboratory of Dr. Jorge Galan at Yale University from 2009-2014.  She was appointed as an Assistant Professor in the Department of Microbiology & Immunology, College of Veterinary Medicine, at Cornell University in September 2014.

Research Description

My laboratory studies Salmonella Typhi pathogenesis, the biology of typhoid toxin, and the host responses to typhoid toxin.

Salmonella enterica serovar Typhi (S. Typhi) is the causative agent of typhoid fever, which remains a major global health issue resulting in ~200,000 annual deaths, mostly among children in developing countries.  There are continuing outbreaks of typhoid fever in some developing countries, and multi drug-resistant strains of S. Typhi is related to the outbreaks in those areas.  Unlike illnesses caused by other S. enterica serovars such as S. Typhimurium, which usually causes restricted infection within the gastrointestinal tract leading to self-limiting gastroenteritis, typhoid fever is a systemic and life-threatening disease.

Typhoid toxin, an essential virulence factor of S. Typhi, is largely missing from nontyphoidal Salmonellae such as S. Typhimurium.  Unlike other bacterial AB5 toxins that are expressed without host cell infections, typhoid toxin with its distinct A2B5 organization is exclusively produced by intracellular S. Typhi, where the toxin is secreted into the lumen of the Salmonella-containing vacuole (SCV) in the infected cells, and then packaged into vesicle carrier intermediates that elicit the export of the typhoid toxin-packaging receptor complex to the extracellular milieu.  Following export, typhoid toxin in circulation can then reach and intoxicate target cells expressing its binding receptor such as the infected cells, neighbor cells, and remotely locating cells, presumably to assist S. Typhi in establishing the successful infection, survival, and transmission of this exclusive human pathogen by influencing its interaction with human hosts throughout various infectious stages. 

We anticipate that our investigations will provide insights into effective strategies to control the serious global health concern that S. Typhi presents.

In addition to providing more information on the virulence of Salmonella Typhi, better understanding the biology of typhoid toxin and host responses to the toxin is significant because some of the well-characterized bacterial toxins have contributed in advancing many areas of biomedical research by serving as a useful tool. Likewise, we anticipate that our study will have a high impact because the results would be able to broadly apply for basic and translational biomedical research.

Selected Publications

Chang S-J, Song J, Galán JE. (2016). Receptor-mediated sorting of typhoid toxin during its export from Salmonella Typhi-infected cells. Cell Host Microbe. 20(5):682-689.

Song J*, Wilhelm CL*, Wangdi T, Maira-Litran T, Lee S-J, Raetz M, Sturge CR, Mirpuri J, Pei J, Grishin NV, McSorley SJ, Gewirtz AT, Baumler AJ, Pier GB, Galán JE, Yarovinsky F.  (2016). Absence of TLR11 in mice does not confer susceptibility to Salmonella Typhi.  Cell. 164(5):827-8 (* co-first authors)

Deng L*, Song J*, Gao X*, Wang J, Yu H, Chen X, Varki N, Naito-Matsui Y, Galán JE, and Varki A.  (2014). Host adaptation of a bacterial toxin from the human pathogen Salmonella Typhi.  Cell.  159(6):1290-9.  (* co-first authors).

Song J*, Gao X*, and Galán JE.  (2013). Structure and function of the Salmonella Typhi chimaeric A2B5 typhoid toxin.  Nature.  499(7458):350-354 (* co-first authors; Highlighted by News and Views in the same issue of the journal; Highlighted by F1000).

Song J*, Willinger T*, Rongvaux A, Eynon EE, Stevens S, Manz MG, Flavell RA, and Galán JE.  (2010). A mouse model for the human pathogen Salmonella Typhi.  Cell Host Microbe.  8(4):369-76. (* co-first authors).

Song J*, Bishop BL*, Li G, Grady R, Stapleton A, and Abraham SN.  (2009). TLR4-mediated expulsion of bacteria from infected bladder epithelial cells.  Proc Natl Acad Sci USA.  106(35):14966-71.  (*co-first authors).

Song J, Bishop BL, Li G, Duncan MJ, and Abraham SN.  (2007). TLR4-initiated and cAMP-mediated abrogation of bacterial invasion of the bladder.  Cell Host Microbe.  1(4):287-298.