[Identification of some atypical (morpho-cultural and enzymatic) characteristics of E. coli strains isolated in different clinical and epidemiological conditions]

From among the 2813 E. coli strains isolated from various specimens (urine, feces, pharyngeal exudates, organs from fowls) in the course of two years, the authors selected and carried out a complex study on the strains exhibiting atypical features, considered to give rise to errors of diagnosis. Of the 2813 strains studied, 599 (21.29%) presented different atypical traits : 45 (1.59%) morphological and cultural (very small pulvurelent colonies or extremely mucous, oily colonies), 21 (0.74%) morphological, cultural and enzymatic atypical aspects and 533 (18.96%) only enzymatic (non-indolegenous strains, strains giving a methyl red reaction, H2S positive strains, lactose-negative and adonite or inosite-positive strains).