The Incidence of Pathogenic Serotypes of E.Coli in Fermented Dairy Products

One hundred and fifty samples of plain yoghurt, fruit yoghurt and laban raib(fifty each)collected from different localities at Zagazig city.Samples weresubjected for chemical and microbiological examination.The mean acidity percent of plain yoghurt, fruityoghurt and laban raib was 1.049,1.360 and 0.956%, while11 23.88x10 , 1.33x10 andthe mean Coliform count/g. was1.81x102, respectively.E. coli was detected in (51.11%) and (21.27%) forexamined plain yoghurt and laban raib samples. Ent. hafniaewere isolated from all products (8.89%, 21,74%, 91.5%)while En t . aerogenes detected only in plain yoghurt and1 a ban r a i b ( 4 . 44%, 4 . 26% ) and En t . c loa c a e is 0 1 ate d from plain yoghurt only (10.64%). Meanwhile Klebsiella spp. andCitrobacter spp. were also isolated from plain yoghurt,fruit yoghurt and laban raib samples in percentage 28.89,and 6.67; 45.83 and 34.78; 38.39 and 29.79%, respectively.Serological identification of isolated E. coli strainsfrom yoghurt and laban raib samples revealed identificationof 7 different serotypesIn bothproducts,°26:K60’ °142:K86’ °119:K69’°86:K61’°114:K90’ °128:K67’ °125:K70’ while E.coli serovars °111:K58’ °126:K71’ °55:K59’