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SA Balajee
SA Balajee

Dr. Balajee is a graduate of the University of Madras (India) and completed her post doctoral training in Dr. Kieren Marr’s laboratory at the Fred Hutchinson Cancer Research Center, Seattle, US. Currently she leads the Molecular Epidemiology Unit within the Mycotic Diseases Branch at the Centers for Disease Control and Prevention.

Dr. Balajee’s dynamic research program is focused on public health mycology that includes studies on the molecular epidemiology of medically important fungi, specifically the genus Aspergillus. Another area of interest is understanding the role of mycotoxins, specifically aflatoxin elaborated by Aspergillus in mediating adverse health effects in humans. Dr. Balajee has published over 25 peer-reviewed articles and several book chapters and is committed to creating a learning environment for budding public health mycologists in her laboratory.  Dr. Balajee is the convenor for an international working group on A. terreus to gather and disseminate scientific knowledge in this field and is a member of the working group on species concepts inAspergillus.

Key Contributions to recent literature:

Contact details:

Arun Balajee Ph.D.
Chief, Molecular Epidemiology Unit,
Mycotic Diseases Branch,
Centers for Disease Control and Prevention Mail stop - G 11 1600 Clifton Road, Atlanta, GA - 30333

Email [email protected]

Phone - 404 639 3337
Fax - 404 639 3546

Nancy Keller
Nancy Keller

Department of Medical Microbiology
University of Wisconsin

My research focus lies in genetically dissecting those aspects of Aspergillus spp. that render them potent pathogens and superb natural product machines. My laboratory’s research includes elucidation of fungal sporulation and host/pathogen interactions; processes intimately linked to secondary metabolite (e.g. mycotoxin) production. My tactic has been to use the genetic model Aspergillus nidulans to elucidate important biological processes in this genus and then carry this information to the plant pathogens A. flavus and A. parasiticus and the human pathogen A. fumigatus. The former two pathogens contaminate seed crops worldwide with aflatoxin, the most potent naturally occurring carcinogen known. The latter pathogen is now tied with Candida as the most serious human mycopathogen in developed countries where it can cause invasive aspergillosis, a disease with a mortality rate ranging from 50 to 90%.

Areas of fungal biology that my lab has been central in developing include:

I. Genetic Regulation of Secondary Metabolism and the Role of Toxic Metabolites in Fungal Virulence.

  • Bok J.-W, Balajee S A, Marr K A, Andes D, Fog Nielsen K. Frisvad J C. Keller N P (2005) LaeA, a regulator of morphogenetic fungal virulence factors. Euk Cell 4:1574-1582.
  • Perrin RM, Fedorova ND, Bok JW, Cramer RA, Wortman JR, Kim HS, Nierman WC, Keller NP. (2007) Transcriptional regulation of chemical diversity in Aspergillus fumigatus by LaeA. PloS Pathogens Apr;3(4):e50.
  • Shwab E., Bok JW, Tribus M, Galehr J, Graessle S, Keller NP. (2007) Histone deacetylase activity regulates chemical diversity in Aspergillus. Euk Cell 6:1656-64

II. Gene silencing processes.

  • Hammond T M, Bok J-W, Andrewski MD, Reyes-Domínguez Y, Scazzocchio C, Keller NP. (2008) RNA silencing gene truncation in the filamentous fungus Aspergillus nidulans. Euk Cell Dec 7(2):339-49
  • Hammond T M, Andrewski MD, Roossinck M, Keller NP. (2008) Aspergillus mycoviruses are targets and suppressors of RNA silencing. Euk Cell 2007 7(2):350-7
  • Bok JW, Noordermeer D, Kale S P, Keller NP (2006) Secondary metabolic gene cluster silencing in Aspergillus nidulans. Mol Microbiol 61:1636-1645

III. Host/fungal signaling.

  • Tsitsigiannis D I, Bok J-W, Andes D, Fog Nielsen K, Frisvad J C, Keller N P (2005) Aspergillus cyclooxygenase-like enzymes are associated with prostaglandin production and virulence. Infect Immun: 73:4548-4559.
  • Brodhagen M, Tsitsigiannis D, Hornung E, Goebel C, Feussner I, Keller NP. (2008) Reciprocal oxylipin-mediated cross talk in the Aspergillus/seed pathosystem. Mol Microbiol 67:378-391

Contact details:

Nancy Keller
3476 Microbial Science Building
Department Medical Microbiology and Immunology
Department of Plant Pathology
1550 Linden Dr., Madison, WI 53706
phone (608) 262-9795
fax (608) 262-8418
[email protected]

Geoffrey Turner
Geoffrey Turner

Professor of Genetics
Department of Molecular Biology and Biotechnology
University of Sheffield 
Sheffield S10 2TN

I have carried out research on filamentous fungi such asAspergillus nidulans andPenicillium 
chrysogenum for about 35 years, on topics such as mitochondrial inheritance, methods for genetic manipulation of fungi, and genetics of penicillin biosynthesis.

Current research interests include the molecular genetics and genomics of secondary metabolism, and polar growth of filamentous fungi, especially Aspergillus nidulans and the opportunistic human and animal pathogen Aspergillus fumigatus.

Secondary metabolism studies have been focussed on the structure and function of non ribosomal peptide synthetases (NRPS), exemplified by ACV synthetase, which assembles the 
tripeptide precursor of penicillin from constituent amino acids. This multienzyme complex is a member of a large family of enzymes which carry out non-ribosomal peptide synthesis in fungi and bacteria, making a wide variety of antibiotics and toxins. We have also investigated the phosphopantetheine transferases required for post-translational modification of peptide synthetases and polyketide synthases.

 Recent genome sequencing projects on A. nidulans and A. fumigatushave revealed an abundance of novel secondary metabolic gene clusters, and we are applying a combination of genetic and chemical approaches to determine their products, some of which have activity against mammalian cells.

Selected earlier publications

  • Rowlands, R.T. and Turner, G. (1976).  Maternal inheritance of extranuclear mitochondrial markers in Aspergillus nidulans.  Genet. Res., Camb. 28, 281-290.
  • Ballance, D.J., Buxton, F.P. and Turner, G. (1983).  Transformation of Aspergillus nidulans by the orotidine-5'-phosphate decarboxylase gene of Neurospora crassa.  Biochem. Res. Commun. 112, 284-289
  • Smith, D.J., Burnham, M.K.R., Bull, J.H., Hodgson, J.E., Ward, J.M., Browne, P., Brown, J. Barton, B., Earl, A.J. and Turner, G. (1990).  ß-lactam antibiotic biosynthetic genes have been conserved in clusters in prokaryotes and eukaryotes.  EMBO J. 9, 741-747.

Selected recent publications

  • Leeder, A.C. and Turner, G. (2007) Characterisation ofAspergillus nidulans polarisome component BemA.  Fungal Genetics and Biology  Dec 8 [Epub ahead of print]
  • Maiya, S.M., Grundman, A., Li. S.M., Li, X. & Turner, G. (2007) Identification of a hybrid PKS/NRPS required for pseurotin A biosynthesis in the human pathogen Aspergillus fumigatus. Chembiochem 8 1736-43.
  • Pel, H.J. et al. (2007) Genome sequencing and analysis of the versatile cell factory Aspergillus niger CBS 513.88 Nature Biotechnology 25, 221-31.
  • Maiya, S.M., Grundman, A., Li, S.M. and Turner, G. (2006) The fumitremorgin gene cluster of Aspergillus fumigatus: identification of a cluster: identification of a gene encoding brevianamide F synthetase. Chembiochem, 7, 1062-1069
  • Johns, S.A., Leeder, A.C., Safaie, M. and Turner, G. (2006) Depletion of Aspergillus nidulans cotA causes a severe polarity defect which is not suppressed by the nuclear migration mutation nudA2. Molecular Genetics and Genomics, 275:593-604.
  • Nierman et al. (2005) Genomic sequence of the pathogenic and allergenic filamentous fungus Aspergillus fumigatus. Nature, 438, 1151-1156
  • Keller, N. P., Turner, G. and Bennett, J. W. (2005) Fungal secondary metabolism – from biochemistry to genomics. Nature Reviews Microbiology, 3, 937-947.
  • Gatherar, I., Pollerman, S., Dunn-Coleman, N. and Turner, G. (2004) Identification of a novel gene hbrB required for polarised growth in Aspergillus nidulans. Fungal Genetics and Biology 41, 463-471.
  • Keszenman-Pereyra, D., Lawrence, S., Twfieg, M.-E., Price, J. and Turner, G. (2003) The npgA/cfwA gene encodes a putative 4'-phosphopantetheinyl transferase which is essential for penicillin biosynthesis in Aspergillus nidulans. Curr Genet, 43, 186-190, 2003
  • Gatherar, I., Pollerman, S., Dunn-Coleman, N. and Turner, G. (2004) Identification of a novel gene hbrB required for polarised growth in Aspergillus nidulans. Fungal Genetics and Biology 41, 463-471.
  • Zarrin, M. Leeder, A., Turner, G. (2005) A rapid method for promoter exchange in Aspergillus nidulans using recombinant PCR. Fungal Genetics and Biology 42, 1-8.


    Department of Molecular Biology and Biotechnology
    University of Sheffield 
    Sheffield S10 2TN
    South Yorkshire 
    Phone 0114 2226211
    [email protected]

William J. Steinbach
William J. Steinbach

Assistant Professor , Division of Pediatric Infectious Diseases, Duke University,USA

Dr. Steinbach is a graduate of University of North Carolina School of Medicine and trained in Pediatrics at Stanford University.  He later completed a pediatric infectious diseases fellowship at Duke University.  He is an associate researcher at the Duke Clinical Research Institute. 

Dr. Steinbach has published over 30 peer-reviewed articles and several book chapters, generally concerning fungal disease and antifungal agents.  He is involved in several clinical trials of newer antifungal agents, including involvement with the NIAID Bacteriology and Mycoses Study Group.  To focus on the issues of fungal disease and treatment in pediatrics, he is also the co-director of the Pediatric Fungal Network.

His basic science interests include in vitro, in vivo, and molecular exploration of A. fumigatus, focusing on mechanisms of pathogenesis as well as optimizing antifungal therapies.  Dr. Steinbach’s clinical interest focuses on invasive aspergillosis diagnosis and management, as well as pediatric fungal infections and the unique characteristics they reveal.  In an effort to unite his basic science and clinical interests, Dr. Steinbach is a co-chairman of the Advances Against Aspergillosis international conference ( 

Recent key contributions to the literature:

  • Steinbach WJ, Stevens DA.  Review of newer antifungal and immunomodulatory strategies for invasive aspergillosis. Clinical Infectious Diseases  2003;37(suppl 3):S157-87.
  • Blankenship JR, Steinbach WJ, Perfect JR, Heitman J.  Teaching old drugs new tricks: Reincarnating immunosuppressants  as antifungals.  Current Opinion in Investigational Drugs 2003;4:192-199.
  • Steinbach WJ, Perfect JR.  Newer antifungal therapy for emerging fungal pathogens.  International Journal of Infectious Diseases  2003;7:5-10.
  • Steinbach WJStevens DA, Denning DW.  Combination and sequential antifungal therapy for invasive aspergillosis:  Review of published in vitro and in vivo interactions and 6281 cases from 1966-2001.  Clinical Infectious Diseases  2003;37(suppl 3):S188-224.
  • Benjamin DK Jr., Poole C, Steinbach WJ, Rowen JL, Walsh TJ.  Neonatal candidemia and end-organ damage:  A critical appraisal of the literature using meta-analytic techniques. Pediatrics  2003;112:634-640.
  • Benjamin DK Jr., DeLong ER, Steinbach WJ, Cotton CM, Walsh TJ, Clark R.  Empirical therapy for neonatal candidemia in very low birthweight infants.  Pediatrics  2003;112:543-547.
  • Steinbach WJ, Marr KA.  Mould infections following hematopoietic stem cell transplantation.  In:  Bowden RA, Ljungman P, Paya CV  (eds).  Transplant Infections, Second Edition, Philadelphia.  Lipppincott Williams and Wilkins.  2003;466-482
  • Steinbach WJ, Schell WA, Blankenship JR, Onyewu C, Heitman J, Perfect JR. In vitro interactions between antifungals and immunosuppressants against Aspergillus fumigatus. Antimicrob Agents Chemother. 2004 May;48(5):1664-9.
  • Steinbach WJ, Benjamin DK Jr, Kontoyiannis DP, Perfect JR, Lutsar I, Marr KA, Lionakis MS, Torres HA, Jafri H, Walsh TJ. Infections due to Aspergillus terreus: a multicenter retrospective analysis of 83 cases. Clin Infect Dis. 2004 Jul 15;39(2):192-8.
  • Steinbach WJ, Perfect JR, Schell WA, Walsh TJ, Benjamin DK Jr. In vitro analyses, animal models, and 60 clinical cases of invasive Aspergillus terreus infection. Antimicrob Agents Chemother. 2004 Sep;48(9):3217-25. Review.
  • Steinbach WJ, Benjamin DK Jr, Trasi SA, Miller JL, Schell WA, Zaas AK, Foster WM, Perfect JR. Value of an inhalational model of invasive aspergillosis. Med Mycol. 2004 Oct;42(5):417-25.
  • Steinbach WJ, Singh N, Miller JL, Benjamin DK Jr, Schell WA, Heitman J, Perfect JR. In vitro interactions between antifungals and immunosuppressants against Aspergillus fumigatus isolates from transplant and nontransplant patients.Antimicrob Agents Chemother. 2004 Dec;48(12):4922-5.
  • Steinbach WJ. Pediatric aspergillosis: disease and treatment differences in children. Pediatr Infect Dis J. 2005 Apr;24(4):358-64. Review.
  • Steinbach WJ. Antifungal agents in children. Pediatr Clin North Am. 2005 Jun;52(3):895-915, viii. Review.
  • Dvorak CC, Steinbach WJ, Brown JM, Agarwal R. Risks and outcomes of invasive fungal infections in pediatric patients undergoing allogeneic hematopoietic cell transplantation. Bone Marrow Transplant. 2005 Oct;36(7):621-9.
  • Steinbach WJ. New findings and unique aspects in pediatric aspergillosis. Med Mycol. 2005 May;43 Suppl 1:S261-5.
  • Steinbach WJ. Combination antifungal therapy for invasive aspergillosis: utilizing new targeting strategies. Curr Drug Targets Infect Disord. 2005 Sep;5(3):203-10. Review.
  • Steinbach WJ, Benjamin DK. New antifungal agents under development in children and neonates. Curr Opin Infect Dis.2005 Dec;18(6):484-9.


Division of Pediatric Infectious Diseases
Box 3499
Duke University Medical Center
Durham, NC  27710 USA

Tel +1 (919) 684-6335
Fax +1 (919) 416-9268
Email:  [email protected]