H-serotyping
The study of flagellate H serotypes obtained from fecal samples was used. For this purpose, an agglutination method was used; the study was performed on a slide according to the generally accepted recommendations (De Barjac & Frachon, 1990). The test was performed by referring the H antiserum against B. thuringiensis H-serotypes 1-58. Hence, motile isolates were termed non-typeable as non-reactive against the reference H antiserum; isolates without flagellation were found; the presence of a strong degree of autoagglutination was considered as well. Bacterial serotypes were identified according to the nature of their flagellate H-antigens. However, antisera prepared to the H antigens may share several common antibodies. Monospecific antisera containing one particular antibody were prepared by saturating aliquots of basal antisera with selected antigens one at a time and removing undesirable antibodies by centrifugation after completing the precipitation reaction. Such monospecific antisera allow the detailed typing bacteria with common antigenic subfactors as serotypes.