Bio

Clinical Focus


  • Infectious Disease

Academic Appointments


Professional Education


  • Medical Education:Loyola University Chicago Stritch School Of Medicine (1992) IL
  • Internship:St Joseph Hospital (1994) IL
  • Board Certification: Infectious Disease, American Board of Internal Medicine (2005)
  • Fellowship:Stanford University Medical Center (2005) CA
  • Residency:Loyola University Medical Center (1996) IL
  • BS, University of Illinois at Urbana-Champaign, Biology (1988)
  • MD, Loyola University Chicago, Medicine (1992)
  • Internship, St. Joseph Hospital / Northwestern University, Internal Medicine (1994)
  • Residency, Foster G. McGaw Hospital / Loyola University Chicago, Internal Medicine (1996)
  • Fellowship, Stanford University, Infectious Diseases (2007)

Community and International Work


  • Orientation Leader, Support for International Change, Tanzania, Africa

    Topic

    HIV / AIDS prevention

    Populations Served

    Africans living in rural communities

    Location

    International

    Ongoing Project

    Yes

    Opportunities for Student Involvement

    Yes

Research & Scholarship

Current Research and Scholarly Interests


My research explores the genetic diversity of human-associated microbiota in health and disease, and the accompanying host transcriptional response. This work relies largely on the application of cultivation-independent methods. An overarching goal of this research is to illuminate stereotypic patterns of microbial community assembly that are associated with specific clinical syndromes. This includes: i) profiling the commensal microbiota in distinct anatomic sites of interest; ii) identifying uncultivated pathogens associated with cryptic infections; iii) enumerating fastidious and minority constituents of polymicrobial infections; and, iv) characterizing perturbations of mixed microbial communities that confer increased disease risk. To achieve these aims, we are using various broad-range molecular approaches, including highly-parallel and quantitative methods, to characterize spatial, temporal and dose-response associations of specific microbial groups with physiologic and pathologic host states. The methodologies I use include, among others, sequence analysis of rDNA clone libraries, real-time quantitative PCR, microbial rDNA-based microarrays, and human cDNA-based microarrays.

The current thrust of my research emphasizes microbial invasion of the amniotic cavity in association with cryptic cases of preterm delivery. We are fortunate to have an ongoing collaboration with the research group of Roberto Romero, MD, Chief, Perinatology Research Branch, NICHD, NIH to investigate - in a broad and comprehensive manner - patterns of microbial prevalence, diversity and abundance that are associated with preterm delivery and its adverse neonatal sequelae. We also seek to characterize, by means of genome-scale transcriptional profiling of the host response, gene expression patterns that are predictive of preterm delivery.

Teaching

Graduate and Fellowship Programs


Publications

Journal Articles


  • Microbial invasion of the amniotic cavity in pregnancies with small-for-gestational-age fetuses. J Perinat Med. DiGiulio DB, Gervasi M, Romero R, Vaisbuch E, Mazaki-Tovi S, Kusanovic JP, Seok KS, Gómez R, Mittal P, Gotsch F, Chaiworapongsa T, Oyarzún E, Kim CJ, Relman DA. 2010; May 20
  • Prevalence and Diversity of Microbes in the Amniotic Fluid, the Fetal Inflammatory Response, and Pregnancy Outcome in Women with Preterm Prelabor Rupture of Membranes. Am J Reprod Immunol DiGiulio DB, DiGiulio DB, Romero R, Kusanovic JP, Gmez R, Kim CJ, Seok KS, Gotsch F, Mazaki-Tovi S, Vaisbuch E, Sanders K, Bik EM, Chaiworapongsa T, Oyarzn E, Relman DA 2010; 64 (1): 38-57
  • Microbial invasion of the amniotic cavity in preeclampsia as assessed by cultivation and sequence-based methods. J Perinat Med DiGiulio DB, Gervasi M, Romero R, Mazaki-Tovi S, Vaisbuch E, Kusanovic JP, Seok KS, Gómez R, Mittal P, Gotsch F, Chaiworapongsa T, Oyarzún E, Kim CJ, Relman DA 2010; May 20
  • Majority Rules? Tallying the Microbial Census in an Abscess by Means of Molecular Methods. Clin Infect Dis DiGiulio DB, Relman DA 2009; 48 (9): 1179-81
  • Microbial Prevalence, Diversity and Abundance in Amniotic Fluid During Preterm Labor: A Molecular and Culture-Based Investigation PLOS ONE DiGiulio, D. B., Romero, R., Amogan, H. P., Kusanovic, J. P., Bik, E. M., Gotsch, F., Kim, C. J., Erez, O., Edwin, S., Relman, D. A. 2008; 3 (8)

    Abstract

    Preterm delivery causes substantial neonatal mortality and morbidity. Unrecognized intra-amniotic infections caused by cultivation-resistant microbes may play a role. Molecular methods can detect, characterize and quantify microbes independently of traditional culture techniques. However, molecular studies that define the diversity and abundance of microbes invading the amniotic cavity, and evaluate their clinical significance within a causal framework, are lacking.In parallel with culture, we used broad-range end-point and real-time PCR assays to amplify, identify and quantify ribosomal DNA (rDNA) of bacteria, fungi and archaea from amniotic fluid of 166 women in preterm labor with intact membranes. We sequenced up to 24 rRNA clones per positive specimen and assigned taxonomic designations to approximately the species level. Microbial prevalence, diversity and abundance were correlated with host inflammation and with gestational and neonatal outcomes. Study subjects who delivered at term served as controls. The combined use of molecular and culture methods revealed a greater prevalence (15% of subjects) and diversity (18 taxa) of microbes in amniotic fluid than did culture alone (9.6% of subjects; 11 taxa). The taxa detected only by PCR included a related group of fastidious bacteria, comprised of Sneathia sanguinegens, Leptotrichia amnionii and an unassigned, uncultivated, and previously-uncharacterized bacterium; one or more members of this group were detected in 25% of positive specimens. A positive PCR was associated with histologic chorioamnionitis (adjusted odds ratio [OR] 20; 95% CI, 2.4 to 172), and funisitis (adjusted OR 18; 95% CI, 3.1 to 99). The positive predictive value of PCR for preterm delivery was 100 percent. A temporal association between a positive PCR and delivery was supported by a shortened amniocentesis-to-delivery interval (adjusted hazard ratio 4.6; 95% CI, 2.2 to 9.5). A dose-response association was demonstrated between bacterial rDNA abundance and gestational age at delivery (r(2) = 0.42; P<0.002).The amniotic cavity of women in preterm labor harbors DNA from a greater diversity of microbes than previously suspected, including as-yet uncultivated, previously-uncharacterized taxa. The strength, temporality and gradient with which these microbial sequence types are associated with preterm delivery support a causal relationship.

    View details for DOI 10.1371/journal.pone.0003056

    View details for Web of Science ID 000264796300003

    View details for PubMedID 18725970

  • Development of the human infant intestinal microbiota PLOS BIOLOGY Palmer, C., Bik, E. M., DiGiulio, D. B., Relman, D. A., Brown, P. O. 2007; 5 (7): 1556-1573

    Abstract

    Almost immediately after a human being is born, so too is a new microbial ecosystem, one that resides in that person's gastrointestinal tract. Although it is a universal and integral part of human biology, the temporal progression of this process, the sources of the microbes that make up the ecosystem, how and why it varies from one infant to another, and how the composition of this ecosystem influences human physiology, development, and disease are still poorly understood. As a step toward systematically investigating these questions, we designed a microarray to detect and quantitate the small subunit ribosomal RNA (SSU rRNA) gene sequences of most currently recognized species and taxonomic groups of bacteria. We used this microarray, along with sequencing of cloned libraries of PCR-amplified SSU rDNA, to profile the microbial communities in an average of 26 stool samples each from 14 healthy, full-term human infants, including a pair of dizygotic twins, beginning with the first stool after birth and continuing at defined intervals throughout the first year of life. To investigate possible origins of the infant microbiota, we also profiled vaginal and milk samples from most of the mothers, and stool samples from all of the mothers, most of the fathers, and two siblings. The composition and temporal patterns of the microbial communities varied widely from baby to baby. Despite considerable temporal variation, the distinct features of each baby's microbial community were recognizable for intervals of weeks to months. The strikingly parallel temporal patterns of the twins suggested that incidental environmental exposures play a major role in determining the distinctive characteristics of the microbial community in each baby. By the end of the first year of life, the idiosyncratic microbial ecosystems in each baby, although still distinct, had converged toward a profile characteristic of the adult gastrointestinal tract.

    View details for Web of Science ID 000249124400020

    View details for PubMedID 17594176

  • Scedosporium apiospermum soft tissue infection successfully treated with voriconazole: Potential pitfalls in the transition from intravenous to oral therapy JOURNAL OF CLINICAL MICROBIOLOGY Schaenman, J. M., DiGiulio, D. B., Mirels, L. F., McClenny, N. M., Berry, G. J., Fothergill, A. W., Rinaldi, M. G., Montoya, J. G. 2005; 43 (2): 973-977

    Abstract

    An immunocompromised patient with an invasive soft tissue infection due to Scedosporium apiospermum was successfully treated with voriconazole and surgical debridement. After transition from intravenous to oral therapy, successive adjustments of the oral dose were required to achieve complete resolution. For soft tissue infections due to molds characterized by thin, septate hyphae branching at acute angles, voriconazole should be considered a first-line antifungal agent. The potential usefulness of plasma voriconazole levels for guiding optimal therapy should be investigated.

    View details for DOI 10.1128/JCM.43.2.973-977.2005

    View details for Web of Science ID 000227045600082

    View details for PubMedID 15695722

  • Human monkeypox: an emerging zoonosis LANCET INFECTIOUS DISEASES Di Giulio, D. B., Eckburg, P. B. 2004; 4 (1): 15-25

    Abstract

    Human monkeypox is a rare viral zoonosis endemic to central and western Africa that has recently emerged in the USA. Laboratory diagnosis is important because the virus can cause disease that is clinically indistinguishable from other pox-like illnesses, particularly smallpox and chickenpox. Although the natural animal reservoir of the monkeypox virus is unknown, rodents are the probable source of its introduction into the USA. A clear understanding of the virulence and transmissibility of human monkeypox has been limited by inconsistencies in epidemiological investigations. Monkeypox is the most important orthopoxvirus infection in human beings since the eradication of smallpox in the 1970s. There is currently no proven treatment for human monkeypox, and questions about its potential as an agent of bioterrorism persist.

    View details for Web of Science ID 000187806000019

    View details for PubMedID 14720564

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