title: Phage lysin to supplement phagebiotics to decontaminate processed sputum specimens.
abstract: The overgrowth of normal flora escaping the action of sputum processing chemicals is the major problem in broth-based tuberculosis (TB) detection systems. The use of phages to control the overgrowth of normal flora in processed sputum samples has already been established. Phage lysin and its supplementation to phagebiotics for the effective control of normal flora in sputum specimens were evaluated. Crude lysin was prepared from phage host mixture using standard procedures. About 120 sputum samples processed with 4% NaOH were collected and used to evaluate the effect of lysin, phagebiotics and phagebiotics supplemented with lysin on the overgrowth of normal flora. The effect of phagebiotics and lysin on the growth and retrieval of Mycobacterium tuberculosis was studied by conventional methods and the luciferase reporter phage (LRP) assay. Lysin alone and phagebiotics supplemented with lysin arrested the growth of normal flora in a significantly greater number of samples than phagebiotics alone. Lysin and phagebiotics did not show any inhibitory activity on M. tuberculosis. The use of antibiotics can be replaced by lysin or phagebiotics supplemented with lysin to control the overgrowth of normal flora in processed sputum samples without hampering the viability of M. tuberculosis.
authors.affiliation: Tuberculosis Research Centre (Indian Council of Medical Research), Mayor V. R. Ramanathan Road, Chetput, Chennai, Tamil Nadu, 600 031, India.
authors.forename: Balaji
authors.initials: B
authors.lastname: Subramanyam
authors.forename: Vanaja
authors.initials: V
authors.lastname: Kumar
authors.forename: Venkatesan
authors.initials: V
authors.lastname: Perumal
authors.forename: Selvakumar
authors.initials: S
authors.lastname: Nagamiah
mesh_terms: D017103:Bacillus Phages / Q000201:enzymology / Q000502:physiology*; D001431:Bacteriological Techniques; D003666:Decontamination / Q000379:methods; D006090:Gram-Negative Bacteria / Q000254:growth & development* / Q000821:virology; D006094:Gram-Positive Bacteria / Q000254:growth & development* / Q000821:virology; D006801:Humans; D006867:Hydrolases / Q000378:metabolism*; D008156:Luciferases; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000254:growth & development* / Q000302:isolation & purification; D012680:Sensitivity and Specificity; D012972:Sodium Hydroxide; D013183:Sputum / Q000382:microbiology*; D014376:Tuberculosis / Q000175:diagnosis*; D014764:Viral Proteins / Q000378:metabolism
chemical_list: D014764:Viral Proteins; D012972:Sodium Hydroxide; D008156:Luciferases; D006867:Hydrolases