title: Genotypic detection of rifampicin-resistant M. tuberculosis strains in Syrian and Lebanese patients.
abstract: METHODS
  The incidence of multi- and extensively drug-resistant TB cases is increasing in many countries. Resistance to rifampicin is widely considered a surrogate marker for multiple drug resistant TB. No efforts have been made to identify and quantify the drug-resistant genotypes in the Syrian and Lebanese communities.
  
  
  OBJECTIVE
  The genotypic characterization of rpo B mutations in the rifampicin drug-resistance region (RRDR) of resistant Mycobacterium tuberculosis isolates in Syrian and Lebanese patients.
  
  
  METHODS
  The pyrosequencing technique was applied to DNA derived from the M. tuberculosis isolates of 56 patients.
  
  
  RESULTS
  RRDR sequencing identified 97 modified codons representing 35 different mutations; 31 (34%) of the 97 modifications were novel and have not been previously reported. The changes were mostly within codons 531 (37/97: 38%), 533 (28/97: 29%) and 526 (9/97: 9%). Additionally, 30 (54%) isolates had multiple codon changes.
  
  
  CONCLUSIONS
  This study indicates the importance of the RRDR hotspot region for the detection of rifampicin resistance in MTB clinical isolates from Syrian and Lebanese patients. However, new mutations and mutations in other locations within the RRDR were also observed. The vast majority (95%) of the studied isolates from this pool of patients contained mutations in codons 531 and/or 533.
authors.affiliation: National Commission for Biotechnology, Damascus, Syria.
authors.forename: Abdulkader
authors.initials: A
authors.lastname: Rahmo
authors.forename: Zahraa
authors.initials: Z
authors.lastname: Hamdar
authors.forename: Imad
authors.initials: I
authors.lastname: Kasaa
authors.forename: Fouad
authors.initials: F
authors.lastname: Dabboussi
authors.forename: Monzer
authors.initials: M
authors.lastname: Hamze
mesh_terms: D000904:Antibiotics, Antitubercular / Q000627:therapeutic use*; D060005:Genotyping Techniques; D006801:Humans; D007861:Lebanon; D009154:Mutation / Q000235:genetics*; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D012293:Rifampin / Q000627:therapeutic use*; D013593:Syria; D018088:Tuberculosis, Multidrug-Resistant / Q000188:drug therapy / Q000235:genetics / Q000382:microbiology*
chemical_list: D000904:Antibiotics, Antitubercular; D012293:Rifampin