Davoodabadi A, Abaszadeh M, Alavi M, Jafari A, Bouzari S. Detection of enteroaggregative Escherichia colistrains from children with diarrhea by use of multiplex PCR and study of their adherence ability to epithelial cells. Iran J Med Microbiol 2009; 2 (3 and 4) :19-24
URL:
http://ijmm.ir/article-1-124-en.html
1- Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran
2- Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran , saeidbouzari@yahoo.com
Abstract: (15252 Views)
Background and Objectives: Enteroaggregative Escherichia coli (EAEC) is an emerging pathogen that cause
acute and chronic infantile diarrhea. The stacked – brick appearance of EAEC strains to HeLa or Hep-2 cells is
the gold standard assay for the detection of EAEC strains and is different from adherence pattern of EPEC and
DAEC. In the present study, a multiplex PCR ( mPCR ) assay was used for detection of EAEC strains and its
results was compared to HeLa cells adherence assay.
Materials and Methods: In this study the E.coli strains isolated from diarrheal children from Tehran children
medical center were used. The isolates were identified according to standard procedure. The 170 strains were
subjected to mPCR assay. This assay is based on the presence of three plasmid borne genes i.e aaP, aggR , aatA.
The mPCR positive and negative strains were further checked for their adherence patterns on HeLa cells.
Results: the results of mPCR of these strains revealed that 114 (67%) of these strains were identified as EAEC
by this mPCR assay. The frequency of occurance of these genes was 100 %, 96.4 % and 70% for the aaP, aggR,
and aatA genes respectively. The 86.9% of mPCR positive strains were HeLa cell adherent (stacked-brick) and
only 13.1% of mPCR positive strains were not adherent. On the other hand 27.2% of strains that on mPCR assay
were negative, adhered to HeLa cells in a characteristic manner of EAEC isolates (stacked –brick).
Conclusion: the overall results obtained in this study, showed that the mPCR assay used here is able to detect
the strains with HeLa cells adherence characteristic of EAEC isolates. Moreover some strains non-adherent on
HeLa cells was positive with the mPCR visa-versa. In conclusion it seems this mPCR assay is rapid and specific
assay for detection of EAEC strains and especially is suitable for screening large number of isolates in epidemic
situation.
Type of Study:
Original Research Article |
Subject:
Medical Bacteriology Received: 2013/11/15 | Accepted: 2013/11/16 | ePublished: 2013/11/16