Risk of Escherichia coli O157:H7 transmission linked to the consumption of raw milk
E. coli 
O157:H7 is associated with life threatening diseases such as hemorrhagic colitis (HC), 
hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). Raw 
milk is considered a high risk food as it is highly nutritious and serves as an ideal medium for 
bacterial growth. The aim of this study was to investigate the prevalence of 
E. coli 
O157:H7 
in raw cow, goat and buffalo milk samples. MPN-PCR method targeting the major virulence 
rfbE 
gene and 
fliCH 
7 
gene of 
E. coli 
O157:H7 was used. Total of 177 raw milk samples were 
collected from local dairy farms in the state of Selangor, Malaysia. The highest prevalence 
of 
E. coli 
O157:H7 was found in raw cow milk (8.75%) followed by raw goat milk (7.32%) 
and raw buffalo milk (1.79%). The estimated quantity of 
E. coli 
O157:H7 in raw cow, goat 
and buffalo milk ranged from <30 MPN/g to 120 MPN/g. In raw cow and goat milk samples 
examined contain 
E. coli 
O157:H7 microbial load ranged from 30 to 120 MPN/g and 30 to 36 
MPN/g, respectively. 
E. coli 
O157:H7 microbial load in buffalo milk samples was found to be 
the lowest, only 30 MPN/g. Results of this research provide useful information on biosafety of 
E. coli 
O157:H7 in raw milk marketed in Malaysia.