Evaluating Trichophyton tonsurans Carriage and Infection
Principal Investigator: Susan M Abdel-Rahman
Abstract: DESCRIPTION (provided by the applicant): Tinea capitis is an overwhelmingly prevalent disease in the pediatric population being estimated to occur in approximately 1 in 20 children. Moreover, an equal and often larger number of children serve as asymptomatic carriers of the pathogen. Of particular interest is that a single species of fungus, namely Trichophyton tonsurans, is responsible for both clinical presentations. With other infectious agents, unique serotypes have been clearly associated with pathogenicity and virulence (e.g., E. coli. M. meningitides, H. influenzae); however, there has been no attempt to identify and link genotypic variants of T. tonsurans with clinical disease status. Recognizing that variants exist and linking specific subtypes to disease presentation is the first step toward identifying distinct molecular targets that may guide the development of therapeutic interventions designed to slow or halt disease transmission and progression. The proposed investigation will employ a targeted molecular analysis in tandem with cross sectional sampling and longitudinal surveillance in a population of normal healthy children to explore the carrier and infection states of T. tonsurans. The investigation will be driven by the general hypotheses: the type of genotypic variant to which a child is exposed accounts for the presentation status observed in Trichophyton tonsurans infection. The hypothesis will be tested by a series of studies designed to address the following specific aims: (1) determine the genotype distribution of T. tonsurans isolates acquired from a fixed population of "high-risk" children and evaluate whether variations in genotype are responsible for differences in disease presentation, specifically infection vs. carriage, between individuals and (2) characterize the degree of relatedness for sequential isolates within an individual and identify whether transformation between disease presentations occurs with the same genetic variant or as a result of acquiring a genetically distinct fungal variant.
Funding Period: 2005-09-20 - 2007-08-31
more information: NIH RePORT
- Genetic predictors of susceptibility to cutaneous fungal infections: a pilot genome wide association study to refine a candidate gene searchSusan M Abdel-Rahman
Division of Pediatric Clinical Pharmacology and Medical Toxicology, The Children s Mercy Hospital and Clinics, Kansas City, MO 64108, USA
J Dermatol Sci 67:147-52. 2012..Trichophyton tonsurans is the foremost fungal pathogen of minority children in the U.S. Despite overwhelming infection rates, it does not appear that this fungus infects children in a non-specific manner...
- Tracking Trichophyton tonsurans through a large urban child care center: defining infection prevalence and transmission patterns by molecular strain typingSusan M Abdel-Rahman
Department of Pediatric Clinical Pharmacology, Children s Mercy Hospitals and Clinics, 2401 Gillham Rd, Suite 0411, Kansas City, MO 64108, USA
Pediatrics 118:2365-73. 2006..This investigation was designed to gain insight into the natural course of T. tonsurans infection...
- Multilocus genotyping identifies infections by multiple strains of Trichophyton tonsuransSusan M Abdel-Rahman
Division of Pediatric Clinical Pharmacology and Medical Toxicology, The Children s Mercy Hospitals and Clinics, Kansas City, MO 64108, USA
J Clin Microbiol 45:1949-53. 2007..This communication details mixed Trichophyton tonsurans infections and highlights the need to confirm the presence of multiple strains in a clinical single isolate by use of a multilocus approach...
- Examining Trichophyton tonsurans genotype and biochemical phenotype as determinants of disease severity in tinea capitisSusan M Abdel-Rahman
Division of Pediatric Clinical Pharmacology, The Children s Mercy Hospitals and Clinics, and Department of Pediatrics, University of Missouri Kansas City, School of Medicine, Kansas City, MO 64108, USA
Med Mycol 46:217-23. 2008..tonsurans cause more severe disease. These observations are consistent with reports that recently diverge anthropophilies are associated with diminished inflammatory involvement...
- A large outbreak of Trichophyton tonsurans among health care workers in a pediatric hospitalJodi Shroba
Department of Nursing, Children s Mercy Hospitals and Clinics, Kansas City, Missouri 64108, USA
Am J Infect Control 37:43-8. 2009..We describe a staff outbreak of T tonsurans infection among health care workers in a freestanding pediatric hospital...
- Divergence among an international population of Trichophyton tonsurans isolatesSusan M Abdel-Rahman
Division of Clinical Pharmacology and Medical Toxicology, Children s Mercy Hospital, 2401 Gillham Road, Suite 0411, Kansas City, MO 64108, USA
Mycopathologia 169:1-13. 2010..The degree of genetic variation observed in this study coupled with the geographic localization would support the argument for allopatric divergence within this species...