An alternative sputum processing method using chitin for the isolation of Mycobacterium tuberculosis

Abstract

An alternative bio-friendly sputum processing method is the need of the hour to augment the rate of detection of TB cases and to improve the sensitivity of rapid growth based diagnostic methods. Chitin, mucolytic in nature and present ubiquitously in animal kingdom, was found to have decontaminating activity when used for processing sputum specimens. The aim of the present study is to develop an alternative bio friendly sputum processing method using chitin. Smear microscopy was done on direct sputum samples and on the deposits obtained after processing with modified Petroff's method as well as Chitin method. Two direct smears were made from each of the sputum samples and stained by Ziehl Neelsen and Auramine phenol (AP) method. The samples were divided in to two aliquots and processed by chitin and modified Petroff's method. Smears were made from each of the deposits and stained by both methods. The deposits were inoculated on to two Lowenstein Jensen slopes. AP method showed a sensitivity of 95% in direct smear. Samples processed by chitin and the deposit smears stained by AP method showed a sensitivity of 80% and a specificity of 89% compared to that of modified Petroff's method. The sensitivity of chitin culture is 87% and the specificity is 85%. Chitin-H 2 So 4 solution took less time compared to 4% NaOH to homogenize the mucopurulent sputum specimens. Chitin-H 2 So 4 can be used as an alternative method of sputum processing for the detection of M. tuberculosis.

Effect of bacteriophage lysin on lysogens

“…Fifty-nine sputum samples were collected, aliquoted into two, randomized and processed by modified Petroff's method and chitin-H 2 SO 4 method [4] . To the deposits, 1 mL of phagebiotics-lysin mixture was added and incubated at 37 曟 up to 4 days.…”

Phage lysin as a substitute for antibiotics to detect Mycobacterium tuberculosis from sputum samples with the BACTEC MGIT 960 system

“…Primary isolation of Mycobacterium tuberculosis from sputum samples, on either solid or liquid media, and identification of the drug sensitivity pattern is essential for determination of the disease status of a patient. Overgrowth of normal flora escaping the action of the sputum‐processing agent is a major problem that affects the sensitivity of any rapid assay [1]. Combinations of antibiotics, in the form of either polymyxin B, amphotericin B, nalidixic acid, trimethoprim and azlocillin (PANTA) or polymyxin B, amphotericin B, carbenicillin and trimethoprim (PACT), and other compounds are incorporated into the media used for the primary isolation of tubercle bacilli to minimize the risk of non‐mycobacterial contamination.…”