Comparison of standard most probable number method with three alternate tests for detection of bacteriological water quality indicators

Abstract

AbstractThe standard most probable number (MPN) method for the detection of total and fecal coliforms was compared with three simple microbial tests: H2S paper strip test, Presence‐absence (P‐A) test for coliforms using MacConkey broth (PA‐TC), and P‐A test for fecal streptococci using KF streptococcal broth (PA‐FS) in 187 samples of water from three districts of Indian state of Jammu and Kashmir: Doda, Udhampur, and Jammu. All three tests were comparable with the standard MPN method. However, the PA‐FS and H2S tests were found more sensitive in the detection of indicator organisms. Four hundred and fifty eight cultures obtained from positive tests were identified in order to evaluate the specificities of tests used in detection of coliform indicators. The low incidence of recovery of Escherichia coli (16–34%) for the standard MPN method places doubt on the validity of its application in tropical areas. In view of this, the need for relaxed standards of water quality in tropical areas is discussed. From the results reported here it appears that the combination of the PA‐FS and H2S test could be used as a suitable multiple test to assess the microbiological quality of drinking water in India and other tropical countries. © by John Wiley & Sons, Inc.