Evaluation of inhouse- PCR assay for rapid screening diagnosis of
Mycobacterium tuberculosis (TB-PCR) in sputum samples
การประเมินผลการตรวจคัดกรองหาเชื้อวัณโรคด้วยเทคนิคทางอณูวิทยา (inhouse-PCR)
ในเสมหะ
Roongrueng Jarumanokul, Medical Technologist, D. of Pathology, F. of Medicine, PSU.
Manthana Phengmak, Medical Technologist, D. of Pathology, F. of Medicine, PSU.
Cherdsak Mahawong, Medical Technologist, D. of Pathology, F. of Medicine, PSU.
Suthus Thongbun, Medical Laboratory Assistant, D. of Pathology, F. of Medicine, PSU.
Wanna Intasara, Medical Laboratory Assistant, D. of Pathology, F. of Medicine, PSU.
Angkana Chaiprasert, D. of Microbiology, F. of Medicine, Siriraj Hospital, Mahidol U., Bangkok
Corresponding e-mail : jroongru@ratree.psu.ac.th
Presented : The 16th Annual Academic Meeting, Faculty of Medicine, PSU., Hat Yai,
Songkhla, 16-18 August 2000
Key words : sputum samples, Mycobacterium tuberculosis, TB diagnosis, TB-PCR
The inhouse-PCR for rapid screening diagnosis of Mycobacterium tuberculosis (TB-PCR) was compared with mycobacterial culture, the MB BacT/Alert system. A total of 80 sputum samples from 78 patients, who suspected Mycobacterial infection. Twenty seven samples demonstrated a positive growth index on the MB BacT/Alert system, 16 samples were Mycobacterium tuberculosis complex and 11 samples were non Mycobacterium tuberculosis complex. Only 9 samples in 16 samples
(56.25%) were positive by TB-PCR. Fourteen samples were positive by AFB stain, 11 samples (69%) were Mycobacterium tuberculosis and 3 samples were Mycobacterium species. All TB-PCR negative samples were also negative when cultured and stained with AFB. These data suggest that TB-PCR is not enough sensitivity to using as single screening assay for TB diagnosis. The TB-PCR assay is still limited for using as the screening detection. However, TB-PCR assay could be detected Mycobacterium tuberculosis complex faster than the MB BacT/Alert about 1-2 week.
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