Epidemiology of parasites of companion small animals; Strongyloides stercoralis: Host modification of developmental decisions.
Key words: Strongyloides stercoralis, parasite behavior, canine and feline parasites, Parasitology.
Description of Research
My major area of research centers on the control of autoinfection in infections with the nematode Strongyloides stercoralis, a parasite of dogs and man. To this end, in collaboration with Dr. Gerry Schad, we have developed the gerbil as a model for this infection. The gerbil is the only rodent in which all aspects of the parasite's life cycle, including autoinfection, have been shown to take place. In the gerbil model we have shown that autoinfection will take place under certain immunosuppressive conditions (inhibitors of T-cell IL 2 regulation, i.e. treatment with tacrolimus, or general immunosuppression, i.e. steroid treatment). Autoinfection has also been observed in immunologically naive gerbils (i.e., neonatally infected gerbils or gerbils infected per os with adult worms). Th 1 inducing infections (i.e. Toxoplasma gondii) and a large initial infection can also induce subsequent autoinfection. We are currently looking at the role of the amphidial neurons in developmental decisions made by the larval worms.
I am also interested in the epidemiology of parasitic infections in dogs and cats. As director of the clinical parasitology laboratory at the University of Pennsylvania School of Veterinary Medicine, I am constantly monitoring the trends in parasite prevalence in the animals that pass through our facility.
Nolan T J, Megyeri Z, Bhopale V M, Schad G A Strongyloides stercoralis: the first rodent model for uncomplicated and hyperinfective strongyloidiasis, the Mongolian gerbil (Meriones unguiculatus). The Journal of infectious diseases 168: 1479-84, 1993.T. J. Nolan, M. Brenes, F. T. Ashton, X. Zhu, W. M. Forbes, R. Boston and G. A. Schad The amphidial neuron pair ALD controls the temperature sensitive choice of alternative developmental pathways in the parasitic nematode, Strongyloides stercoralis Parasitology 129: 753-759, 2004.Maureen C. Gates and Thomas J. Nolan Risk factors for endoparasitism in dogs: retrospective case-control study of 6,553 veterinary teaching hospital cases. Journal of Small Animal Practice 50: 636-640, 2009.Seiler GS, Nolan TJ, Withnall E, Reynolds C, Lok JB, Sleeper MM Computed tomographic changes associated with the prepatent and early patent phase of dirofilariasis in an experimentally infected dog. Vet Radiol Ultrasound 51: 136-140, 2010.Li Xinshe, Massey Holman C, Nolan Thomas J, Schad Gerhard A, Kraus Kelly, Sundaram Meera, Lok James B Successful transgenesis of the parasitic nematode Strongyloides stercoralis requires endogenous non-coding control elements. International journal for parasitology 36: 671-9, 2006.Maureen C. Gates and Thomas J. Nolan Trends in heartworm, flea, and tick preventative use from patients presenting to a veterinary teaching hospital. Preventive Veterinary Medicine . 93: 193-200, 2009.Martin Montes, Cesar Sanchez, Kristien Verdonck, Jordan E. Lake, Elsa Gonzalez, Giovanni Lopez, Angelica Terashima, Thomas Nolan, Dorothy E. Lewis, Eduardo Gotuzzo and A. Clinton White Jr. Regulatory T cell expansion in HTLV-1 and strongyloidiasis co-infection is associated with reduced Interleukin-5 responses to Strongyloides stercoralis antigen.
PLoS Neglected Tropical Infectious Diseases 3: e456, 2009.Nolan Thomas J, Zhu Xiaodong, Ketschek Andrea, Cole Joan, Grant Warwick, Lok James B, Schad Gerhard A The sugar glider (Petaurus breviceps): a laboratory host for the nematode Parastrongyloides trichosuri. The Journal of parasitology 93: 1084-9, 2007.Lok James B, Knight David H, Nolan Thomas J, Grubbs Steven T, Cleale Ralph M, Heaney Kathleen Efficacy of an injectable, sustained-release formulation of moxidectin in preventing experimental heartworm infection in mongrel dogs challenged 12 months after administration. Veterinary parasitology 128: 129-35, 2005.Junio Ariel B, Li Xinshe, Massey Holman C, Nolan Thomas J, Todd Lamitina S, Sundaram Meera V, Lok James B Strongyloides stercoralis: cell- and tissue-specific transgene expression and co-transformation with vector constructs incorporating a common multifunctional 3' UTR. Experimental parasitology 118: 253-65, 2008.