Identification of and in Formalin-Fixed and Paraffin-Embedded Skin Samples from Mexico.

Background: The causative agents of leprosy are the well-known and the newly discovered . This agent was found in 2008, and it was found to be the cause of diffuse lepromatous leprosy in two Mexican patients.

Objective: The objective of this work was to determine if and were present in formalin-fixed and paraffin-embedded skin samples from cases from different regions in Mexico.

Methods: A total of 41 skin samples were obtained from 11 states of Mexico. All patients' samples were diagnosed by clinical and histopathological analyses. Total DNA was isolated using a Qiagen-DNeasy blood and tissue kit and molecular identification was achieved by two semi-nested polymerase chain reactions.

Results: The 41 patient included 33 samples from men and 8 samples from women; 29 samples were polymerase chain reaction (PCR)-positive to and 12 samples were PCR-negative. From those 29 samples, 13 were PCR-positive to , 8 to and 8 were positive to both species. The histopathological diagnosis included; Nodular lepromatous leprosy (NLL); Diffuse lepromatous leprosy (DLL); and Borderline leprosy (BL). The 29 PCR-positive samples were classified as follow: 14 NLL, 4 DLL, and 11 BL. In the 12 samples negative to , 7 showed the NLL, 2 DLL and 3 BL.

Conclusion: These findings add evidence to the and distribution, clinical forms and participation of dual infections in Mexico.