Studies on Cultural Biochemical and Pathogenicty Characters of Local Strains of CL Tetani =

A total of 577 faecal and animal dwelling samples w’re enriched directly on modified 1% glucose cooked meat media and incubated anaerobically for 18 hours at 37 C ,then smears were stained by idirect fluorescent antibody0technique (I.F.A.T). The results showed that 25.6% of faecesand 33.9% of animal dwelling samples were positive to C1.tetani demonstrationIsolation procedures revEaledthe isolation of 20.2% of faeca]. samples with the recovery of 84 straina,wbile the recovery rate of from animal dwellings was comparatively higher than in faeces(25.4%) •It organism either in faeces or animal dwellings. As the total samples positive to I.F.A.T. were 162 in an incidence of28.1%,while the total isolates were 125 strains of .tet4 in an incidence of 21.7%.Biochemical reactions of the 125 isolates showed thatonly 27 isolates were glucose fermenters,100% indole positive, 100% produced an areas of opacity in milk agar,78.4% pathogenic strains and protected with antitetanic serum. from the 84faecal strains 66 were pathogenic and 18 were non-pathogenic while ott. of 41 dwelling strains 32 were pathogenic and9 we !wn-- otho9enic0 Toxigenicity of the cultural filtrate of the total isolates were determined by the measurement of M.L.D./ml.in mice and flocculation units and times (LF and KF),The results showed that toxigenicity with MIL.D. in micewas parallel to the pathogenicity and protection testwhere 78.4% of strains were toxigenic,but did not agreedwith the results of flocculation test(70.4%)According to quantitative values of M.L.D./rnJ. in rnie thetozigenic pathogenic strains were differentiated into :—14 highly toxigenic strains (1x105 LL.D./ml.).—79 moderate toxigenic strains (io—io M.L.D./mi.).-5 weakly toxigenic strains (l—6x102 M.L.D./ml.).-27 non—toxigenic strains.Comparativeiy,the LF units were grouped to :-10 highly flocculatiag strains (60—90 LF units/mi).—32 moderate ii (25—55 LF units/mi).-46weak (15—20 LF units/mi).—37 non—flocculatipg strains.