B.Sc. (Honors), University of Leeds, United Kingdom.
PhD University of Birmingham, United Kingdom.
(W): (814) 393-2161
Office: RM 261 STC
Society for General Microbiology, UK
American Society for Microbiology, USA
Chlamydia Basic Research Society, USA
American Society for Microbiology Florida Branch, USA
BIOL111 Basic Biology
BIOL341 General Microbiology
BIOL483 Molecular Biology
My research interests concern molecular mechanisms of bacterial pathogenesis in relation to human health. I focus on a highly specialized “nanomachine” called the type-III secretion system (T3SS) that is used by a wide variety of medically and environmentally significant bacterial species to mediate host-pathogen interactions. Briefly, the T3SS, which is often referred to as a “molecular syringe,” allows the bacterial pathogen to inject anti-host “effector” molecules directly into its target host cell. This process occurs in a single step, and is considered an essential virulence determinant. Effector proteins act to subvert host-cellular processes and manipulate them to the advantage of the bacterium. I have studied this mechanism in several species of bacteria including Escherichia coli O157:H7 (a highly pathogenic strain associated with undercooked ground beef products), Yersinia (the causative agent of bubonic plague), Chromobacterium violaceum (a soil organism that can cause fatal infection of humans), and Chlamydia trachomatis (the leading cause of sexually transmitted disease in the US, and the leading cause of infectious blindness in developing countries).
My continuing research focus is the T3SSs of the purple pigment producing bacterium, C. violaceum, an organism commonly found in soil and water in tropical and sub-tropical regions. This microbe is currently considered an opportunistic pathogen that causes rare but often fatal infections in humans and other mammals. However, a high proportion of cases are not within the immuno-compromised, and the incidence of infections appears to be on the rise, suggesting that C. violaceum could represent a significant emerging human pathogen. Most importantly, the mechanisms of pathogenicity utilized by this organism remain under-defined. My lab focuses on investigating how type-III secretion functions in this organism and contributes to human virulence.
Betts-Hampikian, H.J. and Fields, K.A. Dec 2011. Disulfide bonding within components of the Chlamydia type-III secretion apparatus correlates with development. JBacteriol. 193(24):6950-9.
Betts-Hampikian, H.J. and Fields, K.A. Oct 2010. The Chlamydial type III secretion mechanism: revealing cracks in a tough nut. Front. Microbio. 1:114.
Betts, H.J., Wolf, K., Fields, K.A. Feb 2009. Effector protein modulation of host cells: examples in the Chlamydia spp. arsenal. Curr Opin Microbiol. 12(1):81-7.
Betts, H.J., Twiggs, L.E., Sal, M.S., Wyrick P.B., Fields, K.A. Mar 2008. Bioinformatic and biochemical evidence for the identification of the type III secretion system needle protein of Chlamydia trachomatis. JBacteriol. 190(5):1680-90.
Betts, H.J., Bailey, C.M., Pallen, M.J., Henderson, I.R. 2005. Bacterial secretion systems., in Bacterial-Epithelial Cell Cross-Talk Molecular Mechanisms in Pathogenesis, pages 60-98, Cambridge University Press
Betts, H.J., Chaudhuri, R.R., Pallen, M.J. Nov 2004. An analysis of Type-III secretion gene clusters in Chromobacterium violaceum. Trends Microbiol. 12(11): 476-82