title: Prevalence and risk factors of drug-resistant tuberculosis in border provinces of Iran.
abstract: OBJECTIVE
  Rapid detection of mycobacterium tuberculosis (MTB) resistance is a key step in the control of disease. This study aimed to identify the prevalence and accuracy of isoniazid (INH) and rifampin (RMP) resistance and their risk factors using multiplex allele-specific polymerase chain reaction (MAS-PCR) to detect such mutations.
  
  
  METHODS
  In this cross-sectional study (2012-2013), 257 MTB patients from five frontier border provinces of Iran were selected and after divulging a full clinical history and undergoing a physical evaluation, the accuracy of drug resistance detection was carried out using the standard proportion test, sequencing, and GeneXpert/rifampicin (RIF) technique. Full demographic and environmental histories were evaluated.
  
  
  RESULTS
  The overall frequency of mutations was 34. Frequency of patients with mutations in KatG315 and at least one rpoB codon (of 516, 526, and 531 codons) were seven cases (2.7%). In comparison to the standard proportion test, the sensitivity and specificity of MAS-PCR in detecting common INH-resistant mutations were 68.75 and 100%, and in the detection of common RMP-resistant mutation were 81.8 and 100%, respectively. Also, 88.89% of KatG 315 mutations and 100% of rpoB mutations were diagnosed and compared with DNA sequencings. Compared to GeneXpert/RIF, 100% of RMP common point mutation was determined by MAS-PCR. Mutation odds were higher in males and greater in those with a history of anti-tuberculosis treatment.
  
  
  CONCLUSIONS
  The results of this study indicated that MAS-PCR is an efficient method for rapid detection of mutations leading to RMP resistance but merely to KatG it is not satisfactory for the detection of INH resistance. Accurate and rapid detection of drug resistance is crucial in males and patients with a history of tuberculosis.
authors.affiliation: Tuberculosis and Lung Disease Research Center, Tabriz University of Medical Science , Tabriz , Iran.
authors.forename: Leyla
authors.initials: L
authors.lastname: Sahebi
authors.forename: Khalil
authors.initials: K
authors.lastname: Ansarin
authors.forename: Safar
authors.initials: S
authors.lastname: Farajnia
authors.forename: Amir
authors.initials: A
authors.lastname: Monfaredan
authors.forename: Siamak
authors.initials: S
authors.lastname: Sabour
mesh_terms: D000328:Adult; D000368:Aged; D001426:Bacterial Proteins / Q000235:genetics; D002374:Catalase / Q000235:genetics; D003430:Cross-Sectional Studies; D012321:DNA-Directed RNA Polymerases; D005260:Female; D006801:Humans; D007492:Iran; D007538:Isoniazid; D008297:Male; D008875:Middle Aged; D060885:Multiplex Polymerase Chain Reaction; D009154:Mutation / Q000235:genetics; D009169:Mycobacterium tuberculosis; D015995:Prevalence; D012293:Rifampin; D012307:Risk Factors; D012680:Sensitivity and Specificity; D018088:Tuberculosis, Multidrug-Resistant / Q000175:diagnosis* / Q000453:epidemiology*
chemical_list: D001426:Bacterial Proteins; C505805:rpoB protein, Mycobacterium tuberculosis; D002374:Catalase; C480353:katG protein, Mycobacterium tuberculosis; D012321:DNA-Directed RNA Polymerases; D007538:Isoniazid; D012293:Rifampin
keywords: Mycobacterium tuberculosis; drug-resistant; microbial sensitivity test; multiplex allele-specific PCR