Abstract

Molecular identification and antimicrobial susceptibility of enteroaggregative Escherichia coli (EAEC) associated with childhood diarrhea was done out in Egypt. The usefulness of quantitative biofilm assay in detection of EAEC was compared with multiplex polymerase chain reaction (PCR). One hundred and fifty cases of childhood diarrhea were divided into three groups; 50 cases of acute diarrhea (group I), 50 cases of persistent diarrhea (group II) and 50 cases of healthy subjects of matched age and sex as a control group (group III). E. coli was isolated and identified by conventional microbiological methods. EAEC was detected by multiplex PCR and quantitative biofilm assay. Antimicrobial susceptibility profile of the isolated EAEC strains was done using disc diffusion method. E. coli was isolated from 78% (39/50) cases of acute diarrhea and 76% (38/50) cases of chronic diarrhea. The results show no significant difference between the results of multiplex PCR and quantitative biofilm assay; in 77 E. coli isolates, 15 (19.5 %) generated positive results for EAEC with multiplex PCR for two the specific genes AggR and EAST and 12 (15.6 %) strains showed positive results for EAEC by quantitative biofilm assay. As regard the antimicrobial susceptibility profile of the isolated EAEC strains, the results show that 85.7 and 87.5% of the EAEC strains isolated from cases of acute and persistent diarrhea, respectively were sensitive to amikacin, 47.1 and 62.5% were sensitive to cefoperazone, 28.5 and 50.00% were sensitive to ceftriaxone and 42.8% and 62.5% were sensitive to imepenem, 28.5 and 12.5 % of the EAEC strains isolated from cases of acute and persistent diarrhea respectively were sensitive to Amoxicillin-Clavulanic. All the isolated EAEC strains (100.00%) were resistant to sulphamethoxole/trimethoprim. High incidence of EAEC associated diarrhea among pediatric cases in Egypt must be considered before decision of antimicrobial therapy. Quantitative biofilm assay can be simple, rapid and convenient method for detection of EAEC in comparison with molecular methods and can therefore be recommended as a rapid screening test for EAEC in clinical laboratories.

Key words: Enteroaggregative Escherichia coli (EAEC), infantile diarrhea, multiplex polymerase chain reaction (PCR), quantitative biofilm.