Four biochemical tests for identification of probable enteroinvasive Escherichia coli strains.
Enteroinvasive Escherichia coli (EIEC) share important features with Shigella spp., but EIEC strains are difficult to identify because their biochemical reactions are variable, and Sereny tests or other biological and molecular assays are expensive or hard to perform. The aim of this work was to detect probable enteroinvasive E. coli strains by using four biochemical tests, in children under 5 years of age with and without acute diarrhea. 330 strains of E. coli isolated from children with diarrhea, and 660 strains from children without diarrhea were studied. All strains were tested with the following tests: mucus , lysine and ornithine decarboxylase and motility. The strains which were negative to the four tests were tested by Sereny assay. Twelve strains (3.6%) isolated from children with diarrhea were negative to the tests proposed; eleven were lactose positive and only one was lactose negative. Three strains (0.5%) from children without diarrhea were negative to the tests proposed and were lactose positive. All the 15 strains (100%) were positive in Sereny assay. We recommend the use of these four biochemical tests for initial detection of EIEC strains, because their cost is very low and it is feasible carry out them in small diagnostic laboratories.
Laboratorio de Microbiología Centro de Investigaciones Regionales Dr. Hideyo Noguchi Universidad Autónoma de Yucatán, México.
J J
JJ
Flores Abuxapqui
G J
GJ
Suárez Hoil
M R
MR
Heredia Navarrete
M A
MA
Puc Franco
M L
ML
Vivas Rosel
D016667:Bacterial Capsules / Q000032:analysis*; D001426:Bacterial Proteins / Q000032:analysis*; D001431:Bacteriological Techniques; D002262:Carboxy-Lyases / Q000032:analysis*; D002675:Child, Preschool; D003967:Diarrhea / Q000382:microbiology*; D003968:Diarrhea, Infantile / Q000382:microbiology; D004403:Dysentery / Q000382:microbiology*; D004926:Escherichia coli / Q000201:enzymology / Q000302:isolation & purification / Q000472:pathogenicity* / Q000502:physiology; D004927:Escherichia coli Infections / Q000382:microbiology*; D005069:Evaluation Studies as Topic; D005240:Feasibility Studies; D005285:Fermentation; D006801:Humans; D007223:Infant; D007785:Lactose / Q000378:metabolism; D009955:Ornithine Decarboxylase / Q000032:analysis; D014774:Virulence
D001426:Bacterial Proteins; D002262:Carboxy-Lyases; D009955:Ornithine Decarboxylase; C021520:lysine decarboxylase; D007785:Lactose