Differentiation between Shigella, enteroinvasive Escherichia coli (EIEC) and noninvasive Escherichia coli

• Published in: European journal of clinical microbiology & infectious diseases 2012-06, Vol.31 (6), p.899-904
• Main Authors: van den Beld, M. J. C., Reubsaet, F. A. G.
• Format: Article
• Language: English
• Subjects: Antigens; Bacteriological Techniques - methods; Biochemical characteristics; Biochemistry; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Classification; Diagnosis, Differential; Differentiation; Dysentery; Dysentery, Bacillary - diagnosis; Dysentery, Bacillary - microbiology; E coli; Escherichia coli; Escherichia coli - classification; Escherichia coli - isolation & purification; Escherichia coli Infections - diagnosis; Escherichia coli Infections - microbiology; Genes; Genomes; Humans; Infectious diseases; Internal Medicine; Laboratories; Medical Microbiology; Medical sciences; Molecular Diagnostic Techniques - methods; Physiology; Polymerase chain reaction; Review; Shigella; Shigella - classification; Shigella - isolation & purification; Typing; Waterborne diseases
• ISSN: 0934-9723; 1435-4373
• DOI: 10.1007/s10096-011-1395-7

Shigella causes bacillary dysentery and is classified into four species based on their antigen characteristics. This classification does not reflect genetic relatedness; in fact, Shigella species are so related to Escherichia coli , they should be classified as one distinctive species in the genus Escherichia . The differentiation of Shigella and E. coli is even more complicated with the description of enteroinvasive E. coli (EIEC). EIEC are strains that possess some of the biochemical characteristics of E. coli and have the ability to cause dysentery using the same method of invasion as Shigella does. Sequencing of multiple housekeeping genes indicates that EIEC is more related to Shigella than to non-invasive E. coli . Shigella and EIEC evolved from the same ancestor and form a single pathovar within E. coli . Shigella and EIEC could be separated from other E. coli by a PCR targeting the ipaH -gene; this is a multicopy gene exclusively found in all Shigella and EIEC. It is possible to differentiate Shigella and all E. coli , including EIEC, by using multiple tests, including ipaH -gene PCR, physiological and biochemical typing and serological typing. Based on literature study, a key is designed for daily use in diagnostic laboratories to identify Shigell a and all E. coli .