Identification and differentiation of clinically relevant mycobacterium species directly from acid-fast bacillus-positive culture broth.
Mycobacterium species cause a variety of clinical diseases, some of which may be species specific. Therefore, it is clinically desirable to rapidly identify and differentiate mycobacterial isolates to the species level. We developed a rapid and high-throughput system, MycoID, to identify Mycobacterium species directly from acid-fast bacillus (AFB)-positive mycobacterial culture broth. The MycoID system incorporated broad-range PCR followed by suspension array hybridization to identify 17 clinically relevant mycobacterial complexes, groups, and species in one single reaction. We evaluated a total of 271 AFB-positive culture broth specimens, which were identified by reference standard methods in combination with biochemical and molecular tests. The overall identification agreement between the standard and the MycoID system was 89.7% (perfect match) or 97.8% (one match in codetection). In comparison to the standard, the MycoID system possessed an overall sensitivity of 97.1% and specificity of 98.8%. The 159 Mycobacterium avium-M. intracellulare complex isolates were further identified to the species level by MycoID as being M. avium (n = 98; 61.1%), M. intracellulare (n = 57; 35.8%), and mixed M. avium and M. intracellulare (n = 2; 1.3%). M. avium was recovered more frequently from sterile sites than M. intracellulare (odds ratio, 4.6; P = 0.0092). The entire MycoID procedure, including specimen processing, can be completed within 5 h, providing rapid and reliable identification and differentiation of mycobacterium species that is amenable to automation. Additional differentiation of Mycobacterium avium-M. intracellulare complex strains into M. avium and M. intracellulare may provide a tool to better understand the role of Mycobacterium avium-M. intracellulare complex isolates in human disease.
Departments of Pathology1 and Medicine,2 Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA.
Haijing
H
Li
Vedat
V
Turhan
Laxmi
L
Chokhani
Charles W
CW
Stratton
Sherry A
SA
Dunbar
Yi-Wei
YW
Tang
D015373:Bacterial Typing Techniques; D003470:Culture Media; D015342:DNA Probes; D021903:DNA, Ribosomal Spacer / Q000032:analysis; D006801:Humans; D009161:Mycobacterium / Q000145:classification* / Q000235:genetics / Q000254:growth & development*; D009164:Mycobacterium Infections / Q000175:diagnosis* / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000379:methods*; D011237:Predictive Value of Tests; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D013045:Species Specificity
D003470:Culture Media; D015342:DNA Probes; D021903:DNA, Ribosomal Spacer; D012336:RNA, Ribosomal, 16S; D012338:RNA, Ribosomal, 23S; D011933:Reagent Kits, Diagnostic