Infection and Drug Resistance (Nov 2019)

Efficacy Of Line Probe Assay In Detection Of Drug-Resistant Pulmonary Tuberculosis In Comparison With GeneXpert And Phenotypic Methods In Iran And Genetic Analysis Of Isolates By MIRU-VNTR

  • Kazemian H,
  • Kardan-Yamchi J,
  • Bahador A,
  • Khonsari S,
  • Nasehi M,
  • Hamzehloo G,
  • Vaziri F,
  • Salehi MR,
  • Feizabadi MM

Journal volume & issue
Vol. Volume 12
pp. 3585 – 3593

Abstract

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Hossein Kazemian,1 Jalil Kardan-Yamchi,2 Abbas Bahador,1 Shadi Khonsari,3 Mahshid Nasehi,4 Gholamreza Hamzehloo,5 Farzam Vaziri,6 Mohammad Reza Salehi,7 Mohammad Mehdi Feizabadi1,8 1Department of Medical Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; 2Division of Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; 3Natural Science Department, School of Science and Technology, Middlesex University, London, UK; 4Department of Epidemiology and Biostatistics, Iran University of Medical Sciences, Tehran, Iran; 5Tehran Regional Reference Laboratory for Tuberculosis, Tehran, Iran; 6Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran; 7Department of Infectious Disease, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran; 8Thoracic Research Center, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, IranCorrespondence: Mohammad Mehdi FeizabadiDepartment of Medical Microbiology, School of Medicine, Tehran University of Medical Sciences, Poursina Street, Engelab-e-Eslami Avenue, Tehran, IranTel +989121767987Fax +982188955810Email [email protected]: Successful treatment of tuberculosis depends on early diagnosis and use of appropriate drug susceptibility testing in a timely manner. In the present study, LPA efficacy was assayed in detection and drug susceptibility testing of pulmonary tuberculosis in comparison to available methods in Iran and phylogenetic analyses of isolated cases carried out by MIRU-VNTR.Methods: This study was conducted at the Tehran Regional Reference Laboratory for Tuberculosis. All sputum specimens were subjected to smear, culture, and drug susceptibility testing (DST), GeneXpert, and LPA. Finally, 15-locus-based MIRU-VNTR was used for molecular genotyping.Results: From a total of 920 sputum specimens, 6.08% (n=56) were identified as MTBC by culture, 6.8% (n=63) by GeneXpert, and 6.5% (n=60) by LPA. Phenotype DST and LPA methods confirmed the resistance of 4 and 14 specimens to rifampin (RIF) and isoniazid (INH); two cases were considered as multidrug-resistant (MDR). Using GeneXpert, four cases were identified as RIF-resistant. Based on LPA results, inhA and katG mutations were detected in 100% and 21.4% of INH-resistant cases, respectively. All 56 culture positive Mycobacterium tuberculosis isolates were placed in 29 different clusters using MIRU-VNTR genotyping. Two MDR-TB, 2 RIF mono-resistant, and 12 INH mono-resistant cases were placed in different clusters.Conclusion: LPA is an appropriate method for early detection and accurate diagnosis of TB and drug-resistant cases that makes it possible to distinguish INH mono-resistant cases from MDR cases in Iran.Keywords: tuberculosis, line probe assay, early diagnosis, drug resistance, mutation

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