03017nas a2200265 4500000000100000008004100001260001200042653003300054653003500087653005900122653002500181653001200206100001400218700001400232700001100246700001200257700001200269700001200281245019800293856007200491300001000563490000600573520215800579022001402737 2020 d c01/202010aAcid-fast bacilli microscopy10aRLEP-polymerase chain reaction10ainter-simple sequence repeat-polymerase chain reaction10alaboratory diagnosis10aleprosy1 aMohanty P1 aBansal AK1 aNaaz F1 aPatil S1 aArora M1 aSingh M00aDominant marker (inter-simple sequence repeat-polymerase chain reaction) versus codominant marker (RLEP-polymerase chain reaction) for laboratory diagnosis of leprosy: A comparative evaluation. uhttp://www.ijmyco.org/temp/IntJMycobacteriol9118-5569304_152813.pdf a18-230 v93 a

Background: Leprosy is a contagious disease and was eliminated globally in 2002. Since then, new cases were continuously detected from different parts of the world. Untreated leprosy cases shed millions of bacteria and are the main cause of dissemination of the disease. Currently, leprosy is detected by acid-fast bacilli (AFB) microscopy and has a low sensitivity ranging from 10% to 50%. The correlation between clinical findings and microscopy is unable to provide a conclusive case detection. Thus, in the present study, we compared to molecular methods, namely RLEP-polymerase chain reaction (RLEP-PCR) and inter-simple sequence repeat-PCR (ISSR-PCR) taking AFB microscopy as a gold standard for the detection of leprosy.

Methods: A total of 168 clinically diagnosed leprosy patients were recruited in this study including 58 multibacillary and 110 paucibacillary patients. Slit-skin smear samples were taken for both microscopy and molecular study. Primers for RLEP-PCR were taken from the previous reports. The primers for ISSR-PCR were designed by screening the whole genome of Mycobacterium leprae TN strain (GenBank accession AL450380) for the presence of simple sequence repeats. One primer (TA)CAwas synthesized and used for molecular amplification of ISSR-PCR.

Results: We found that the efficacy of the AFB microscopy was 24.40%, whereas the efficacy of RLEP-PCR and ISSR-PCR was 63.09% and 73.21% (P = 0.000, 0.000, and 0.469), respectively. The area under the curve of receiver operating characteristic curve for the comparison of three diagnostic methods was 0.845. An enhancement of 48.81% in the case detection rate by ISSR-PCR over AFB microscopy and 10.12% over RLEP-PCR was also found. Our study clearly reveals that ISSR-PCR is a better tool for diagnosis of leprosy than AFB microscopy and RLEP-PCR. Interestingly, both the PCR techniques RLEP-PCR and ISSR-PCR are able to detect samples which were negative for AFB microscopy.

Conclusion: Thus, the demonstration of ISSR-PCR in SSS samples can provide a better sensitive and confirmative tool for early diagnosis of leprosy.

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