COMPLEX CLONAL FEATURES IN AN MYCOBACTERIUM TUBERCULOSIS INFECTION IN A TWO-YEAR-OLD CHILDde Viedma, Darío García PhD; Marín, Mercedes PhD; Andrés, Sandra; Lorenzo, Gema PhD; Ruiz-Serrano, María Jesús; Bouza, Emilio MD, PhDPediatric Infectious Disease Journal: May 2006 - Volume 25 - Issue 5 - pp 457-459 doi: 10.1097/01.inf.0000217473.90673.00 Brief Reports Abstract Author Information The focus of this report is to describe the highly complex clonal features of the Mycobacterium tuberculosis (MTB) isolates cultured from a 2-year-old child with no risk factors for tuberculosis. Molecular analysis showed that she was coinfected by 2 MTB isolates. The coinfecting isolates showed only subtle genetic differences and shared equivalent infectivity in vitro; however, they were infecting independent anatomic sites (compartmentalized infection). One of the MTB isolates was cultured only from respiratory specimens, whereas the other was isolated from extrarespiratory site (central nervous system). From the *Servicio de Microbiología Clínica y Enfermedades Infecciosas, Hospital Gregorio Marañón, Madrid, Spain. Accepted for publication January 30, 2006. This study was partially financed by grants from Comunidad de Madrid (08.2/0029.1/2001; GR/SAL/0488/2004) and Fondo de Investigaciones Sanitarias (PI020882, 030654). Address for correspondence: Darío García de Viedma, Servicio de Microbiología y Enfermedades Infecciosas, Hospital Gregorio Marañón, C/Dr Esquerdo 46, 28007 Madrid. E-mail email@example.com. © 2006 Lippincott Williams & Wilkins, Inc.