Application of cetylpyridinium chloride and sodium chloride decontamination method for recovery of Mycobacterium tuberculosis from clinically suspected cases of pulmonary tuberculosis

Long‐Term Storage at −80°C: Effect on Rate of Recovery of Mycobacterium tuberculosis From Direct Acid‐Fast Bacilli Smear‐Positive Sputum Samples

“…Literatures suggest that the sputum samples with higher smear scores (3+ and 2+) yield growth of MTB within 2–4 weeks when compared to sputum with lower smear scores (1+ and scanty) . This statement was consistent in our study as well.…”

“…In the current study, mucopurulent sputum specimens constituted 65.11% of the AFB direct smear-positive cases and the remaining sputum specimens include mucoid (20.16%), blood tinged (12.4%), and salivary (2.33%). This finding was comparable with previous reports as well (20,22). Further, mucopurulent sputum samples yielded 68.1%, 67.47%, and 67.52% of MTB growth on LJ media, BBL MGIT TM system, and MB 7H11 agar media, respectively (before storage).…”

“…Previous workers recommend the use of combination of both solid and liquid media for effective isolation of MTB form clinical specimens (10). However, in this study, none of the systems (both before storage and after storage) could detect growth of MTB in four specimens (mucopurulent, n = 1 [smear grade 2+], mucoid, n = 2 [smear grade 1+] and n = 1 [smear grade 3+]).This may be because of decontamination process adopted in the current study; more specifically, exposure to alkali (sodium hydroxide in the current study) kills few strains of mycobacteria (20). Further, all the culture techniques (after storage) failed to detect growth of MTB in seven cases (mucopurulent, n = 1 [smear grade 2+], mucoid, n = 3 [smear grade 1+] and n = 1 [smear grade 3+], blood tinged, n = 2 [smear grade 1+]) including all the four sputum samples (before storage).…”

“…Further, all the culture techniques (after storage) failed to detect growth of MTB in seven cases (mucopurulent, n = 1 [smear grade 2+], mucoid, n = 3 [smear grade 1+] and n = 1 [smear grade 3+], blood tinged, n = 2 [smear grade 1+]) including all the four sputum samples (before storage). This may be explicated on the fact that the recovery of MTB strains from clinical specimens depends on many factors such as decontamination process used, physiological and chemical nature of clinical specimen (these properties may be altered after long‐term storage) . Further, none of the culture systems could detect growth of NTM and M. bovis from all the clinical specimens studied.…”

Papain-cetylpyridinium chloride and pepsin-cetylpyridinium chloride; two novel, highly sensitive, concentration, digestion and decontamination techniques for culturing mycobacteria from clinically suspected pulmonary tuberculosis cases

“…However, an appropriate digestion and decontamination method (DDM) is essential for the effective recovery of Mycobacterium tuberculosis (MTB) in culture. In the past years, various DDMs have been established to isolate MTB from clinical specimens [2][3][4][5][6][7][8][9]. However, paucity of research data and operational challenges, more specifically; availability of chemicals, costeffectiveness of the method and lack of standardization restricted the implementation of these DDMs in laboratory settings.…”