Operational Handbooks

Nipro (Osaka, Japan) developed Genoscholar PZA-TB, a reverse hybridization-based technology for detection of pyrazinamide (PZA) resistance in tuberculosis (TB) (1, 2). Compared with MTBDRplus and MTBDRs/ LPA, the Genoscholar PZA-TB line-probe assay (LPA) does not include specific mutant probes, because resistance mutations are widespread across the entire pncA gene with no predominant mutations.

Roche Molecular Systems, Inc. (RMS, Roche) has two nucleic acid amplification tests (NAATs), the cobas MTB and cobas MTB-RIF/INH tests, to detect Mycobacterium tuberculosis complex (MTBC) and drug resistance (rifampicin [RIF] and isoniazid [INH]), respectively (1,2) in tuberculosis (TB). The MTB assay detects both 16S rRNA and esx genes as target genes for MTBC detection.

Becton Dickinson (BD) has a multiplexed real-time polymerase chain reaction (PCR) nucleic acid amplification tests (NAAT) (BD MAX MDR-TB) for the detection of Mycobacterium tuberculosis complex (MTBC) and resistance to both rifampicin (RIF) and isoniazid (INH) in tuberculosis (TB). For MTBC detection, this test targets the multicopy genomic elements IS6110 and IS1081, as well as a single copy genomic target.

Abbott Molecular diagnostic solution for tuberculosis (TB) has two nucleic acid amplification tests (NAATs), one for detection of Mycobacterium tuberculosis complex (MTBC) (RealTime MTB test) and one for detection of resistance to both rifampicin (RIF) and isoniazid (INH) (RealTime MTB RIF/INH) (1). TB detection is based on the IS6110 genetic element and the pab gene targets.

The four-tier classification system of biosafety levels (1–4) described in WHO’s Laboratory biosafety manual^² provides broad guidance on basic concepts of biosafety for the development of national and international codes of practice. The challenge for managers of TB programmes and staff at laboratories, particularly in resource-limited settings, has been to interpret the generic risk-group assignments and biosafety levels into specific precautions relevant to a country’s activities.