Isolation of tubercle bacilli from sputum samples of patients in the fieldudstudies by the cetylpyridinium chloride-sodium chloride sodiumudhydroxide methods

摘要

A total of 125 sputum specimens, collected in the field, were homogenised, aliquoted in sterileuduniversal containers and randomly allocated to the cetylpyridinium chloride - sodium chloride (CPCNaCl)udmethod and sodium hydroxide ( NaOH) method for culture of tubercle bacilli. After storageudfor 8 days at ambient temperature in the field laboratory at Thiruvallur, the aliquots were transportedudto the main laboratory at Madras where they were processed for culture by the respectiveudmethods. The yield of positive cultures in the CPC-NaCl (31/125) method was only marginally betterudthan that in the NaOH method (27/125) (95% Cl being-3.4 to 9.8%), while the contamination ofudcultures was significantly less in the CPC-NaCl method ( 3/125) than in the NaOH method (12/125)ud(95% Cl being 2.2 to 12.2%). As the CPC-NaCl method has advantages over the NaOH method inudreducing contamination, in augmenting the yield of positive cultures and also in its simplicity, it canudbe applied in field studies.