Occurrence of coliform bacteria other than Escherichia coli in foods

An evaluation of the BGLB (44 degrees C) confirmation test for the enumeration of E. coli as an index of sanitary quality of some foods was made. Out of 70 samples tested, 43 (61.4%) samples contained E. coli. A total of 347 BGLB gas positive cultures obtained were subjected to the IMViC procedure. It was found that 42.7% of these BGLB gas positives were E. coli and 57.3% were ten other coliform bacteria giving the following IMViC patterns: 31.4% --++, 6.3% -+-+, 4.3% each of +-++ and -+++, 3.2% ++-+, 2.9% ++++, 2% ---+, 1.4% +++-, 1.2% --+- and 0.3% -++-. Some of the possible reasons for obtaining low recovery of E. coli in foods by the BGLB test have been discussed. The various fields to be investigated for the improvement of the test procedure and thus the elimination of false positives have been suggested.