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Biomedical subjects

Claudia Toma

Publications and source records attributed to Claudia Toma.

20 records · Page 2Linked to original sources
PubMed2002

Enteroaggregative Escherichia coli: incidence in Japan and usefulness of the clump-formation test.

The usefulness of the clump-formation test described by Albert et al. for identifying enteroaggregative Escherichia coli (EAggEC) and the incidence of EAggEC in Japan were studied. One hundred and seventy strains of E. coli agglutinated with enteropathogenic E. coli diagnostic antisera were collected from a variety of districts in Japan. All isolates were from diarrheal stools. EAggEC was identified on the basis of the presence of the aggR gene accompanied by aggregative adhesion to HEp-2 cells. After 24 strains carrying eaeA, elt, est, stx-1, stx-2, or ipaH genes were eliminated, the remaining 145 strains were examined for adhesion to Hep-2 cells, the presence of the aggRgene, and clump formation on the surface of Muller-Hinton broth. aggR was detected in 10 strains, and 9 of them displayed aggregative adhesion to HEp-2 cells. Seven strains produced marked clumps and 22 showed moderate clump formation. The sensitivity and specificity of the clump-formation test for detecting EAggEC were each about 90%, and they varied slightly depending on the stringency of evaluation for the degree of clump formation. From these results, we conclude that the incidence of EAggEC cannot be ignored as a possible cause of diarrheal disease in Japan, and we strongly recommend the clump-formation test for detecting EAggEC.

Bacterial Adhesion↗
PubMed2002

Detection of EspB using reversed passive latex agglutination: application to determination of enteropathogenic Escherichia coli.

We developed a new practical method to identify enteropathogenic Escherichia coli (EPEC) by detecting the pathogenic factor, EspB. E. coli were cultured in Dulbecco's Modification of Eagle's Medium (DMEM), and EspB was detected in the culture supernatant by reversed passive latex agglutination (RPLA). All 63 E. coli strains harboring the eaeA gene encoding intimin were positive for RPLA, and all 25 strains without the eaeA gene were negative. Among these 63 eaeA-positive strains, 38 Shiga toxin-producing E. coli (STEC) produced Shiga toxin (Stx) under the same culture conditions (DMEM). Subtypes of EspB alpha, beta and gamma were antigenically cross-reactive to each other as determined by RPLA and Western blotting. A kit for Stx detection (RPLA) is commercially available and therefore this RPLA for detection of EspB could be a practical method to define EPEC in both clinical laboratories and the field.

Antibodies, Bacterial↗