title: Mycobacterium leprae is identified in the oral mucosa from paucibacillary and multibacillary leprosy patients.
abstract: In leprosy, the nasal mucosa is considered as the principal route of transmission for the bacillus Mycobacterium leprae. The objective of this study was to identify M. leprae in the oral mucosa of 50 untreated leprosy patients, including 21 paucibacillary (PB) and 29 multibacillary (MB) patients, using immunohistochemistry (IHC), with antibodies against bacillus Calmette-Guérin (BCG) and phenolic glycolipid antigen-1 (PGL-1), and polymerase chain reaction (PCR), with MntH-specific primers for M. leprae, and to compare the results. The material was represented by 163 paraffin blocks containing biopsy samples obtained from clinically normal sites (including the tongue, buccal mucosa and soft palate) and visible lesions anywhere in the oral mucosa. All patients and 158 available samples were included for IHC study. Among the 161 available samples for PCR, 110 had viable DNA. There was viable DNA in at least one area of the oral mucosa for 47 patients. M. leprae was detected in 70% and 78% of patients using IHC and PCR, respectively, and in 94% of the patients by at least one of the two diagnostic methods. There were no differences in detection of M. leprae between MB and PB patients. Similar results were obtained using anti-BCG and anti-PGL-1 antibodies, and immunoreactivity occurred predominantly on free-living bacteria on the epithelial surface, with a predilection for the tongue. Conversely, there was no area of predilection according to the PCR results. M. leprae is present in the oral mucosa at a high frequency, implicating this site as a potential means of leprosy transmission.
authors.affiliation: Dermatology Unit, Presidente Prudente Regional Hospital, University of Oeste Paulista, Presidente Prudente, SP, Brazil; Department of Dermatology, São Paulo Federal University, São Paulo, SP, Brazil.
authors.forename: M A M
authors.initials: MA
authors.lastname: Morgado de Abreu
authors.forename: A M
authors.initials: AM
authors.lastname: Roselino
authors.forename: M
authors.initials: M
authors.lastname: Enokihara
authors.forename: S
authors.initials: S
authors.lastname: Nonogaki
authors.forename: L E
authors.initials: LE
authors.lastname: Prestes-Carneiro
authors.forename: L L M
authors.initials: LL
authors.lastname: Weckx
authors.forename: M M A
authors.initials: MM
authors.lastname: Alchorne
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001426:Bacterial Proteins / Q000235:genetics; D027682:Cation Transport Proteins / Q000235:genetics; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D056006:Leprosy, Multibacillary / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission; D056005:Leprosy, Paucibacillary / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000382:microbiology*; D009166:Mycobacterium leprae / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D001426:Bacterial Proteins; D027682:Cation Transport Proteins; C433793:MntH protein, bacteria
keywords: Epidemiology; Mycobacterium leprae; immunohistochemistry; leprosy; oral mucosa; polymerase chain reaction