A-1 medium: alternative technique for fecal coliform organism enumeration in chlorinated wastewaters

Abstract

A 24-h most-probable-number technique using A-1 medium for detecting fecal coliforms in chlorinated wastewaters was evaluated. The A-1 medium technique, using 3 h of preincubation at 35°C, gave results statistically equivalent to those obtained with the American Public Health Association Standard Methods twostep most-probable-number technique. The accepted method for determining disinfection efficiency of wastewater treatment systems is routinely to perform fecal coliform bacteria analyses on the final effluent (5). Standard Methods for the Examination of Water and

Relationship among fecal coliforms, Escherichia coli, and Salmonella spp. in shellfish

“…The standard procedures used for enumerating fecal coliforms in waters are described in Standard Methods for the Examination of Water and Wastewater (2) and, for shellfish, Recom-mended Procedures for the Examination of Sea Water and Shellfish (1). Although there are several new methods which have been developed and modified to determine fecal coliforms in a relatively short time period (3,11,13,22), the classical method involves the most probable number (MPN) technique, in which a sample of shellfish homogenate is added to lauryl tryptone broth. The tubes are incubated for 24 to 48 h, and positive tubes are inoculated into E. coli broth.…”

False Positive Fecal Coliform in Biosolid Samples Assayed using A‐1 Medium

“…A‐1 medium, developed by Andrews and Presnell (1972) , was originally formulated for the enumeration of fecal coliform in estuarine water. It has been shown to give results equivalent to the LTB/EC method in the analysis of marine and estuarine water ( Hunt and Springer, 1978 ; Miescier et al, 1978 ), shellfish ( Cook, 1981 ; Hunt et al, 1981 ), and chlorinated wastewater ( Standridge and Delfino, 1981 ) samples also. The incubation of samples inoculated to A‐1 medium at an elevated incubation temperature (44.5°C) used in the Fecal Coliform Direct Test (A‐1 Medium) Method (9221E.2) procedure described in Standard Methods allows for the determination of fecal coliform.…”