Improved detection of Mycobacterium tuberculosis using two independent PCR targets in a tertiary care centre in South India

Authors

  • Ramya Barani Sri Ramachandra University, Porur, Chennai, India
  • Gopalsamy Sarangan Sri Ramachandra University, Porur, Chennai, India
  • Tessa Antony Sri Ramachandra University, Porur, Chennai, India
  • Soundararajan Periyasamy Sri Ramachandra University, Porur, Chennai, India
  • Anupma Jyoti Kindo Sri Ramachandra University, Porur, Chennai, India
  • Padma Srikanth Sri Ramachandra University, Porur, Chennai, India

DOI:

https://doi.org/10.3855/jidc.1302

Keywords:

Mycobacterium tuberculosis, polymerase chain reaction, IS6110, TRC4, South India

Abstract

Introduction:  Tuberculosis (TB) causes significant morbidity and mortality worldwide as one of the leading infectious diseases. In India, more than 1.8 million new cases occur every year. Rapid and accurate diagnosis of TB would improve patient care and limit its transmission.
This study aimed to evaluate a dual target polymerase chain reaction (PCR) diagnostic assay to detect Mycobacterium tuberculosis from pulmonary and extra-pulmonary samples at a tertiary care centre in South India.
Methodology: Samples were collected from patients with a low index of suspicion of TB. Acid-fast smears were performed by Auramine O fluorescent microscopy and PCR was performed by using two site-specific primer pairs targeting IS6110 by nested PCR and TRC4 by conventional PCR. Amplified products for IS6110 and/or TRC4 were indicative of M. tuberculosis.
Results: Among 114 (19 pulmonary and 95 extra-pulmonary) samples tested by PCR assay, 12 (11%) were positive for both IS6110 and TRC4, of which 11 (10%) were non-respiratory and one was (1%) respiratory in origin. PCR for TRC4 alone was positive for eight (7%) non-respiratory and two (2%) respiratory samples, while IS6110 alone tested positive for six (5%) non-respiratory samples and one (1%) respiratory sample. Of a total of 29 PCR positive samples, 17 (15 %) were acid-fast smear positive.
Conclusion: Although the target site of IS6110 is specific for M. tuberculosis, some strains from South India may lack this region. Therefore, the use of an additional target site (TRC4) is required for improved detection of M. tuberculosis.

Author Biographies

Ramya Barani, Sri Ramachandra University, Porur, Chennai, India

Tutor, Department of Microbiology

Sri Ramachandra Medical College & Research Institute, Sri Ramachandra University,Porur, Chennai, india 6oo116

Gopalsamy Sarangan, Sri Ramachandra University, Porur, Chennai, India

Tutor, Department of Microbiology

Sri Ramachandra Medical College & Research Institute, Sri Ramachandra University,Porur, Chennai, india 6oo116

Tessa Antony, Sri Ramachandra University, Porur, Chennai, India

Post-graduate student, Department of Microbiology

Sri Ramachandra Medical College & Research Institute, Sri Ramachandra University,Porur, Chennai, india 6oo116

Soundararajan Periyasamy, Sri Ramachandra University, Porur, Chennai, India

Head, Department of Nephrology

Sri Ramachandra Medical College & Research Institute, Sri Ramachandra University,Porur, Chennai, india 6oo116

Anupma Jyoti Kindo, Sri Ramachandra University, Porur, Chennai, India

Professor, Department of Microbiology

Sri Ramachandra Medical College & Research Institute, Sri Ramachandra University,Porur, Chennai, india 6oo116

Padma Srikanth, Sri Ramachandra University, Porur, Chennai, India

Professor, Department of Microbiology

Sri Ramachandra Medical College & Research Institute, Sri Ramachandra University,Porur, Chennai, india 6oo116

Areas of interest: Clinical virology, healthcare associated infections, tuberculosis, bioaerosols, medical education, quality assurance in the laboratory, public health

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Published

2011-12-02

How to Cite

1.
Barani R, Sarangan G, Antony T, Periyasamy S, Kindo AJ, Srikanth P (2011) Improved detection of Mycobacterium tuberculosis using two independent PCR targets in a tertiary care centre in South India. J Infect Dev Ctries 6:46–52. doi: 10.3855/jidc.1302

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Section

Original Articles