Life Science III 1007
Research Specialities: Developmental Regulation in Chlamydia. Chlamydia spp. are Gram negative, obligate intracellular bacterial pathogens which cause disease in humans as well as economically important domestic animals. These bacteria mainly infect the mucosal epithelial layer lining the lung, ocular, digestive, and genital tracts eliciting damage primarily in the form of immunopathology. In humans, C. trachomatis is responsible for trachoma (the leading cause of preventable blindness worldwide) and is the leading cause of reported bacterial sexually transmitted infections (STIs) in the United States (and worldwide) with over 1.2 million cases reported in 2008 (CDC). C. pneumoniae infects the respiratory tract causing pneumonia. While the incidence of chlamydial pneumonia is unknown, there are over 2 million reported cases of pneumonia in the United States each year (CDC). Furthermore, C. pneumoniae infections are a suspected risk factor for the development of cardiovascular disease and other chronic conditions. While antibiotics are relatively effective in treating chlamydial infections, recent work has demonstrated that resistance against frontline antibiotics is a real threat, demonstrating a need for the discovery of new antibiotic targets. Concurrently, the high percentage of asymptomatic chlamydial infections (≥50% of STIs are asymptomatic), and the link between these infections and chronic disease, illustrates the urgent need to develop vaccines.
PhD, 2006, University of Pittsburgh School of Medicine
Chlamydia spp. transition between two distinct developmental forms, the environmentally stable infectious form known as the elementary body (EB) and the intracellular replicative form known as the reticulate body (RB). For successful reproduction, the EB must bind and become internalized in a eukaryotic cell, modify host-vesicular trafficking pathways, transform into an RB (for binary fission to occur), transition back into an EB and finally exit from the host cell into the environment. Despite this complicated developmental cycle, Chlamydia spp. encode few canonical gene regulators and the mechanisms regulating morphogenesis remain largely undefined. Recently, global bacterial Ser/Thr/Tyr protein phosphorylation has become an increasingly appreciated method for regulating protein function in bacteria. Chlamydia spp. encode two validated Ser/Thr kinases as well as putative protein phosphatases. However, the extent of phosphorylation in Chlamydia is unknown and few protein kinase targets have been identified.
As a first step in determining the role of phosphorylation in chlamydial biology, I recently directed a project to map the phosphoproteome of Chlamydia caviae GPIC EB and RB developmental forms. A well-studied guinea pig infection model exists for C. caviae and the pathology mimics C. pneumoniae and C. trachomatis infections in humans. This research had three key findings: 1) that C. caviae are capable of utilizing global Ser/Thr/Tyr protein phosphorylation (phosphorylating >4% of its proteome), 2) proteins phosphorylated in C. caviae are highly conserved throughout Chlamydia spp. suggestive of a conserved chlamydial phosphoproteome, and 3) that protein phosphorylation is much more prevalent in EBs (3-fold more phosphoproteins) than in RBs. Phosphoprotein profiles of other Chlamydia spp. demonstrate similar phosphoprotein numbers and developmental skewing compared to C. caviae . Collectively, these data led us to hypothesize that phosphorylation plays a key role in regulating morphogenesis. The extent, conservation, and developmental skew of protein phosphorylation provide support for further studies to discern the importance and consequences of protein phosphorylation in Chlamydia.
Consequently, my research will focus on 1) elucidating the triggering mechanism(s) leading to early dephosphorylation events, 2) characterizing the phosphorylation-controlled chlamydial partner switching mechanism, and 3) assessing the role of phosphorylation in regulating key central metabolic enzymes found to be differentially phosphorylated in EBs versus RBs. In addition, my research also will expand upon the recent breakthrough in chlamydial genetics through the development of tools to increase the methods available to genetically manipulate Chlamydia. These projects will provide important insights into the biology of Chlamydia spp., identify pathways that can be targeted to short-circuit its pathogenic abilities, and will generate tools necessary for vaccine creation.
Articles in Professional Journals
- Umagiliyage, A.L., Becerra-Mora, N., Kohli, P., Fisher, D.J., Choudhary, R. (2017) Antimicrobial efficacy of liposomes containing d-limonene and its effect the storage life of blueberries. Postharvest Biology and Technology. DOI: 10.1016/j.postharvbio.2017.02.007
- Claywell, J.E., Matschke, L.M., and Fisher, D.J. (2016) The impact of protein phosphorylation on chlamydial physiology. Frontiers in Cellular and Infection Microbiology. 6:197. Link
- Key, C.E. and Fisher, D.J. (2016) Use of Group II Intron Technology for Targeted Mutagenesis in Chlamydia trachomatis. Methods in Molecular Biology. 1498:163-177. PMID: 27709575 PubMed Link
- Claywell, J.E. and Fisher, D.J. (2016) CTL0511 from Chlamydia trachomatis is a Type 2C Protein Phosphatase (PP2C) with Broad-Substrate Specificity. Journal of Bacteriology. PMID: 27114464 PubMed Link
- Zhang, H., Wang, Q., Fisher, D.J., Cai, M., Chakravartty, V., Ye, H., Li, P., Solbiati, J.O., Feng, Y. (2016) Deciphering a unique biotin scavenging pathway with redundant genes in the probiotic bacterium Lactococcus lactis. Scientific Reports. 6:25680. PMID: 27161258 PubMed Link
- Hooppaw, A.J. and Fisher, D.J.. (2015) A Coming of Age Story: Chlamydia in the Post-Genetic Era. Infection and Immunity. Accepted. (Invited Review). PMID: 26667838 PubMed Link
- Lowden, N.M., Yeruva, L., Johnson, C.M., Bowlin, A.K., Fisher, D.J. 2015. Use of aminoglycoside 3′ adenyltransferase as a selection marker for Chlamydia trachomatis intron-mutagenesis and in vivo intron stability. BMC Research Notes. 8:570. Link
- Thompson, C.C., Griffiths, C., Nicod, S.S., Lowden, N.M., Wigneshweraraj, S., Fisher, D.J., McClure, M.O. 2015. The Rsb phosphoregulatory network controls availability of the primary sigma factor in Chlamydia trachomatis and influences the kinetics of growth and development. PLoS Pathogens. 11(8): e1005125. Link
- Fisher, D.J., Adams, N.E., and Maurelli, A.T. 2015. Phosphoproteomic analysis of the Chlamydia caviae elementary body and reticulate body forms. Microbiology 161: 1648-1658. PMID: 25998263. PubMed link
- Ma, M., Gurjar, A., Theoret, J.R., Garcia, J.P., Beingesser, J., Freeman, J.C., Fisher, D.J., McClane, B.A., and Uzal, F.A. 2014. Synergistic effects of Clostridium perfringens enterotoxin and beta toxin in rabbit small intestinal loops. Infect Immun. 82(7): 2958-2970. PMID: 24778117. PubMed link
- Johnson, C.M and Fisher, D.J. 2013. Site-specific, insertional inactivation of incA in Chlamydia trachomatis using a Group II intron. PLoS ONE 8(12): e83989. PMID: 24391860. Link
- Fisher, D.J., Fernández, R.E., and Maurelli, A.T. 2013. Chlamydia trachomatis transports NAD via the Npt1Ct ATP/ADP translocase. Journal of Bacteriology. 195(15): 3381-6. PMID: 23708130. PubMed link
- Garcia, J.P, Beingesser, J., Fisher, D.J., Sayeed, S., McClane, B.A., Posthaus, H., and Uzal, F.A. (2012) The effect of Clostridium perfringens type C strain CN3685 and its isogenic beta toxin null mutant in goats. Vet Microbiol. 157(3-4): 412-9. PMID: 22296994. PubMed Link
- *Bliven, K.A., *Fisher, D.J., Maurelli, A.T. 2012. Characterization of the activity and expression of arginine decarboxylase in human and animal Chlamydia pathogens. FEMS Microbiology Letters 337:140-6. PMID:23043454. PubMed link *These authors contributed equally to this work.
- Fisher, D.J., Fernández, R.E., Adams, N.E., and Maurelli, A.T. 2012. Uptake of Biotin by Chlamydia Spp. Through the Use of a Bacterial Transporter (BioY) and a Host-Cell Transporter (SMVT). PLOS ONE. PLOS ONE link
- Binet, R., Fernández, R.E., Fisher, D.J. and Maurelli, A.T. 2011. Identification and Characterization of theChlamydia trachomatis L2 S-Adenosyl Methionine / S-Adenosyl Homocysteine transporter. mBio. May 10;2(3):e00051-11. doi: 10.1128/mBio.00051-11. PubMed link
- Giles, T.N., Fisher, D.J. and Graham, D.E. 2009. Independent inactivation of arginine decarboxylase genes by nonsense and missense mutations led to pseudogene formation in Chlamydia trachomatis serovar L2 and D strains. BMC Evolutionary Biology. 9:166. PMCID: PMC2720952 PubMed link
- Uzal, F.A., Saputo, J., Sayeed S, Vidal, J.E., Fisher, D.J., Poon, R., Adams, V., Fernandez-Miyakawa, M.E., Rood, J.I. and McClane, B.A. 2009. Development and application of new mouse models to study the pathogenesis of Clostridium perfringens type C Enterotoxemias. Infection and Immunity. 77(12): 5291-9. PMCID: PMC2786445 PubMed link
- Sayeed, S., Uzal, F.A., Fisher, D.J., Saputo, J., Vidal, J.E., Chen, Y., Gupta, P., Rood, J.I. and McClane, B.A. 2008. Beta toxin is essential for the intestinal virulence of Clostridium perfringens type C disease isolate CN3685 in a rabbit ileal loop model. Molecular Microbiology. 67(1): 15-30. (Figure from paper used for issue cover) PubMed link
- Uzal, F.A., Fisher, D.J., Saputo, J., Sayeed, S., McClane, B.A., Songer, G., Trinh, H.T., Fernandez-Miyakawa, M.E. and Gard, S. 2008. Ulcerative enterocolitis in two goats associated with enterotoxin- and beta2 toxin-positive Clostridium perfringens type D. Journal of Veterinary Diagnostic Investigation. 20(5):668-72. Journal link
- Shivaprasad, H.L. Uzal, F., Kokka, R., Fisher, D.J., McClane, B.A. and Songer, A.G. 2008. Ulcerative enteritis-like disease associated with Clostridium perfringens type A in bobwhite quail (Colinus virginianus). Avian Diseases. 52(4):635-40. PubMed link
- Fernandez-Miyakawa, M.E., Sayeed, S., Fisher, D.J., Poon, R. Adams, V., Rood, J.I., McClane, B.A., Saputo, J. and Uzal, F.A. 2007. Development and application of a mouse oral challenge model for studying Clostridium perfringens type D infection. Infection and Immunity. 75(9): 4282-8. PMCID: PMC1951146 PubMed link
- Chen, Y., Caruso, L., McClane, B., Fisher, D. and Gupta, P. 2007. Disruption of a toxin gene by introduction of a foreign gene into the chromosome of Clostridium perfringens using targetron-induced mutagenesis. Plasmid. 58(2): 182-9. PMCID: PMC2034400 PubMed link
- Miyakawa, M.E., Saputo, J., Leger, J.S., Puschner, B., Fisher, D.J., McClane, B.A. and Uzal, F.A. 2007. Necrotizing enterocolitis and death in a goat kid associated with enterotoxin (CPE)-producing Clostridium perfringens type A. Canadian Veterinary Journal. 48(12): 1266-9. PMCID: PMC2081994 PubMed link
- Fernandez-Miyakawa, M.E., Fisher, D.J., Poon, R., Sayeed, S., Adams, V., Rood, J.I., McClane, B.A. and Uzal, F.A. 2007. Both epsilon-toxin and beta-toxin are important for the lethal properties of Clostridium perfringenstype B isolates in the mouse intravenous injection model. Infection and Immunity. 75(3): 1443-1452. PMCID: PMC1828578 PubMed link
- Crespo, R., Fisher, D.J., Shivaprasad, H.L., Fernandez-Miyakawa, M.E. and Uzal, F.A. 2007. Toxinotypes ofClostridium perfringens isolated from sick and healthy avian species. Journal of Veterinary Diagnostic Investigation. 19(3): 329:33. PubMed link
- Fisher, D.J., Fernandez-Miyakawa, M.E., Sayeed, S., Poon, R., Adams, V., Rood, J.I., Uzal, F.A. and McClane, B.A. 2006. Dissecting the lethality contributions of Clostridium perfringens type C toxins to lethality in the mouse intravenous injection model. Infection and Immunity, 74(9): 5200-5210. PMCID: PMC1594841 PubMed link
- Myers, G.S.A., Rasko, D.A., Cheung, J.K., Ravel, J., Seshadri, R.,DeBoy, R.T., Ren, Q., Varga, J., Awad, M.M., Brinkac, L.M., Daugherty, S.C., Haft, D.H., Dodson, R.J., Madupu, R., Nelson, W.C., Rosovitz, M.J., Sullivan, S.A., Khouri, H., Dimitrov, G.I., Watkins, K.L., Mulligan, S., Benton, J., Fisher, D.J., Atkins, H.S., Hiscox, T., Jost, H., Billington, S.J., Songer, J.G., McClane, B.A., Titball, R.W., Rood, J.I., Melville, S. and Paulsen, I.T. 2006. Skewed Genomic Variability in Strains of the Toxigenic Bacterial Pathogen, Clostridium perfringens. Genome Research, 16: 1031-1040. PMCID: PMC1524862 PubMed link
- Miyamoto, K., Fisher, D.J., Li, J., Sayeed, S., Akimoto, S. and McClane, B.A. 2006. Complete sequencing and diversity analysis of the enterotoxin-encoding plasmids in Clostridium perfringens type A nonfoodborne human gastrointestinal disease isolates. Journal of Bacteriology, 188(4):1585-1598. PMCID: PMC1367241 PubMed link
- Chen, Y., McClane, B., Fisher, D.J., Rood, J. and Gupta, P. 2005. Construction of an Alpha Toxin Gene Knockout Mutant of Clostridium perfringens Type A using a Mobile Group II Intron. Applied and Environmental Microbiology, 71(11):7542-7. PMCID: PMC1287605 PubMed link
- Sayeed, S., Fernandez-Miyakawa, M.E., Fisher, D.J., Adams, V., Poon, R., Rood, J.I., Uzal, F.A. and McClane, B.A. 2005. Epsilon toxin is required for most Clostridium perfringens type D vegetative culture supernatants to cause lethality in the mouse intravenous injection model. Infection and Immunity, 73(11):7413-21. PMCID: PMC1273886 PubMed link
- Fisher, D.J., Miyamoto, K., Sarker, M.R., Harrison, B. And McClane, B.A. 2005. Association of beta2 toxin production with Clostridium perfringens type A human gastrointestinal disease isolates carrying a plasmid enterotoxin gene. Molecular Microbiology 56(3):747-762. PubMed link
- Smedley III, J.G., Fisher, D.J., Sayeed, S., Chakrabarti, G. and McClane, B.A. 2004. The enterotoxins ofClostridium perfringens. Reviews in Physiology, Biochemistry and Pharmacology 72(12):6914-23. (Invited Review) PubMed link
- Zhou, Z., Fisher, D., Spidel, J., Greenfield, J., Patson, B., Fazal, A., Wigal, C., Moe, O.A. and Madura, J.D. 2003. Kinetic and docking studies of the interaction of quinones with the quinone reductase active site. Biochemistry 42(7):1985-94. PubMed link