Competition for proline between indigenous Escherichia coli and E. coli O157:H7 in gnotobiotic mice associated with infant intestinal microbiota and its contribution to the colonization resistance against E. coli O157:H7
Competition for proline between indigenous Escherichia coli and E. coli O157:H7 in gnotobiotic mice associated with infant intestinal microbiota and its contribution to the colonization resistance against E. coli O157:H7
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DOI：
10.1007/s10482-008-9222-6
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发表时间：
2008-02
期刊：
影响因子：
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通讯作者：
Y. Momose;K. Hirayama;K. Itoh
中科院分区：
文献类型：
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作者：
Y. Momose;K. Hirayama;K. Itoh
在此之前，我们生产了两组无菌小鼠，GB-3和GB-4，它们对大肠杆菌O 157：H7攻击表现出不同的反应。大肠杆菌157：H7从GB-3中被清除，而GB-4小鼠成为携带者。据报道，E.大肠杆菌157：H7在50%GB-3盲肠悬液中的生长时间比GB-4盲肠悬液中的生长时间长。在这项研究中，GB-3和GB-4小鼠和E.大肠杆菌157：H7。GB-3和GB-4盲肠内容物中的氨基酸含量不同，尤其是脯氨酸的含量。在GB-3盲肠悬液中添加脯氨酸可缩短E. colio 157：H7体外生长。coliO 157：H7与GB-3小鼠生产用菌株进行体外培养，其中2株E.大肠杆菌（脯氨酸消耗菌）对5株肠杆菌中的E. colio 157：H7的生长，并通过向培养基中添加脯氨酸来减弱抑制。这些结果表明，竞争脯氨酸与土著E。coli对E. colio 157：H7，并可能有助于E.大肠杆菌157：H7从肠道中消除。
Previously, we produced two groups of gnotobiotic mice, GB-3 and GB-4, which showed different responses toEscherichia coliO157:H7 challenge.E. coliO157:H7 was eliminated from GB-3, whereas GB-4 mice became carriers. It has been reported that the lag time ofE. coliO157:H7 growth in 50% GB-3 caecal suspension was extended when compared to GB-4 caecal suspension. In this study, competition for nutrients between intestinal microbiota of GB-3 and GB-4 mice andE. coliO157:H7 was examined. Amino acid concentrations in the caecal contents of GB-3 and GB-4 differed, especially the concentration of proline. The supplementation of proline into GB-3 caecal suspension decreased the lag time ofE. coliO157:H7 growth in vitro.WhenE. coliO157:H7 was cultured with each of the strains used to produce GB-3 mice in vitro, 2 strains ofE. coli(proline consumers) out of 5 enterobacteriaceae strains strongly suppressedE. coliO157:H7 growth and the suppression was attenuated by the addition of proline into the medium. These results indicate that competition for proline with indigenousE. coliaffected the growth ofE. coliO157:H7 in vivo and may contribute toE. coliO157:H7 elimination from the intestine.