肠杆菌科的细菌,现已清楚至少有一种共同的抗原成分,称为肠杆菌共同抗原(简称ECA)。其它革兰氏阴性杆菌或革兰氏阳性细菌中并不存在此种ECA。这种抗原可用间接血凝或其他方法测出。一般ECA常被当作不同属间的交叉反应性来解释。 ECA可能存在于细菌的外层表面,因此,可以初步肯定它包括在细菌与动物宿主的反应中。在肠道菌引起严重感染或慢性感染时,ECA抗体提高,有可能作为诊断的一种标记;还证明ECA抗体有保护作用。已有一些研究资料证实它的临床意义,但尚未引起注意和重视。 Enterobacteriaceae bacteria, it is now clear at least one common antigen component, known as Enterobacteriaceae common antigen (referred to as ECA). This ECA does not exist in other Gram-negative or Gram-positive bacteria. This antigen can be detected by indirect coagulation or other methods. ECAs are often interpreted as cross-reactivity between different genotypes. ECA may be present on the outer surface of the bacteria and therefore, it is tentatively asserted that it is included in the reaction of bacteria and animal hosts. ECA antibodies are raised when gut bacteria cause serious or chronic infections and may serve as a marker for diagnosis; ECA antibodies have also been shown to have protective effects. There are some research data to confirm its clinical significance, but it has not drawn much attention and attention.