title: Nasal PCR assay for the detection of Mycobacterium leprae pra gene to study subclinical infection in a community.
abstract: Leprosy is a chronic infectious disease caused by Mycobacterium leprae. Identification of Mycobacterium leprae is difficult in part due to the inability of the leprosy bacillus to grow in vitro. A number of diagnostic methods for leprosy diagnosis have been proposed. Both serological tests and molecular probes have shown certain potential for detection and identification of Mycobacterium leprae in patients. In this study, we have investigated whether Mycobacterium leprae DNA from the nasal secretion of healthy household contacts and the non contacts could be detected through PCR amplification as a method to study the sub clinical infection in a community. A total of 200 samples, 100 each from contacts and non contacts representing all age groups and sex were included in this study. The M. leprae specific primer (proline-rich region) of pra gene was selected and PCR was performed using extracted DNA from the sample. A total of 13 samples were found to be positive for nasal PCR for pra gene among the male and female contacts out of which 7% were males and 6% were females. Even though several diagnostic tools are available to detect the cases of leprosy, they lack the specificity and sensitivity. PCR technology has demonstrated the improved diagnostic accuracy for epidemiological studies and requires minimal time. Although nasal PCR studies have been reported from many countries it is not usually recommended due to the high percentage of negative results in the contact.
authors.affiliation: Central Leprosy Teaching & Research Institute, Chengalpattu, Tamil Nadu, India.
authors.forename: Kamalanathan
authors.initials: K
authors.lastname: Arunagiri
authors.affiliation: Central Leprosy Teaching & Research Institute, Chengalpattu, Tamil Nadu, India. Electronic address: sangeetha556@gmail.com.
authors.forename: Gopalakrishnan
authors.initials: G
authors.lastname: Sangeetha
authors.affiliation: Department of Biotechnology, Aarupadai Veedu Institute of Technology, Chennai, India.
authors.forename: Padmavathy Krishnan
authors.initials: PK
authors.lastname: Sugashini
authors.affiliation: Pasteur Institute of India, Coonoor, India.
authors.forename: Sekar
authors.initials: S
authors.lastname: Balaraman
authors.affiliation: Central Leprosy Teaching & Research Institute, Chengalpattu, Tamil Nadu, India.
authors.forename: M K
authors.initials: MK
authors.lastname: Showkath Ali
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058345:Asymptomatic Infections / Q000453:epidemiology*; D012634:Bodily Secretions / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D005260:Female; D006801:Humans; D007223:Infant; D007918:Leprosy / Q000175:diagnosis* / Q000453:epidemiology* / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods; D009166:Mycobacterium leprae / Q000235:genetics / Q000302:isolation & purification*; D009666:Nose / Q000382:microbiology*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013997:Time Factors; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial
keywords: Mycobacterium leprae; Nasal; PCR assay; Pra gene; Sub-clinical