本土牛、羊糞便或其生乳中Shiga 毒素產生性大腸桿菌之分佈   全文下載

Prevalence of Shiga Toxin-producing Escherichia coli in Feces and Raw Milk of Domestic Cattle and Sheep

本研究係自1997年9月至1999年6月，從台灣地區之273戶牛羊養殖場採集1060件牛羊生乳或其糞便檢體，經增菌培養、分離後，使用Vitek微生物自動鑑定儀、大腸桿菌Shiga毒素基因PCR反應，進行Shiga毒素產生性大腸桿菌（shiga toxin-producing E. coli, STEC）之檢測。結果顯示，於231件牛羊生乳檢體檢出0.4%污染STEC；829件牛羊糞便檢體中，9%分離出STEC。選取121株STEC，進一步測試其生化特性、血清型及附著（eaeA）與溶血（hlyA）等致病基因。測試結果為僅有3%菌株缺乏β-葡萄糖?酵素（β-D-g1ucuronidase）活性，4%菌株不能醱酵山梨糖醇（sorbitol），以43種O型血清鑑別出之血清型為O6、O8、O15、O78、O112ac、O128、O157及O159，但僅有13%菌株屬於前述血清型，其餘則未鑑別出。H血清型別以22種H型血清測試，計有31%菌株鑑別出，分別為H2、H7、H10、H16、H19、H21、H42、H45及H51。Shiga毒素型別共計三種，檢出率為slt1，39%；slt2，33%；sltl+slt2，28%。70%STEC則具有hlyA基因，其中1.6%菌株則同時帶有hlyA及eaeA基因。另外，從本土羊糞分離出一株E. coli O157:H7，其同時帶有slt2、eaeA及hlyA等致病基因。綜合前述，瞭解台灣地區之牛羊糞便可能為STEC之污染源。"

A total of 1060 samples of raw milk and fecal from cattle and sheep were collected from farms in the Taiwan area between September 1997 and June 1998. Shiga toxin-producing E. coli (STEC) strains were isolated based on the demonstration of Vitek automicrobic system and shiga toxin-PCR after enrichment and selective procedures. The results showed that 0.4% of 231 raw milk samples were contaminated with STEC. Among the 829 fecal samples of cattle and sheep, 9% tested positive for STEC. A total of 121 STEC strains were selected and further analyzed for biochemical tests, serotype and pathogenic genes of eaeA (attaching and effacing) as well as hlyA (enterohemolysin). Results revealed that only 3% of strains lacked β-D-glucuronidase activity and 4% of strains were unable to ferment sorbitol. Thirteen percent of strains were typed as O6, O8, O15, O78, O112ac, O128, O157 and O159 with 43 O-antisera. The remaining strains were non-typeable with O-antisera. Thirty one percent of strains were determined as H2, H7, H10, H16, H19, H21, H42, H45 and H51 with 22 H-antisera. Three types of shiga toxin genes were detected with different rates, namely slt1, 39%; slt2, 33% and slt1+slt2, 28%. Seventy percent of STEC strains harbored hlyA gene and 1.6% possessed hlyA and eaeA genes. In addition, one E. coli O157:H7 strain, isolated from feces of domestic sheep, carried slt2, hlyA and eaeA genes. This study indicates that the feces of cattle and sheep were most likely the source of STEC in the Taiwan area. 本研究係自1997年9月至1999年6月，從台灣地區之273戶牛羊養殖場採集1060件牛羊生乳或其糞便檢體，經增菌培養、分離後，使用Vitek微生物自動鑑定儀、大腸桿菌Shiga毒素基因PCR反應，進行Shiga毒素產生性大腸桿菌（shiga toxin-producing E. coli, STEC）之檢測。結果顯示，於231件牛羊生乳檢體檢出0.4%污染STEC；829件牛羊糞便檢體中，9%分離出STEC。選取121株STEC，進一步測試其生化特性、血清型及附著（eaeA）與溶血（hlyA）等致病基因。測試結果為僅有3%菌株缺乏β-葡萄糖苷酵素（β-D-g1ucuronidase）活性，4%菌株不能醱酵山梨糖醇（sorbitol），以43種O型血清鑑別出之血清型為O6、O8、O15、O78、O112ac、O128、O157及O159，但僅有13%菌株屬於前述血清型，其餘則未鑑別出。H血清型別以22種H型血清測試，計有31%菌株鑑別出，分別為H2、H7、H10、H16、H19、H21、H42、H45及H51。Shiga毒素型別共計三種，檢出率為slt1，39%；slt2，33%；sltl+slt2，28%。70%STEC則具有hlyA基因，其中1.6%菌株則同時帶有hlyA及eaeA基因。另外，從本土羊糞分離出一株E. coli O157:H7，其同時帶有slt2、eaeA及hlyA等致病基因。綜合前述，瞭解台灣地區之牛羊糞便可能為STEC之污染源。