Genetic detection of diarrheagenic Escherichia coli isolated from children with sporadic diarrhea.
Escherichia coli strains are among the major bacterial causes of diarrheal illness. At least 5 categories of diarrheagenic E. coli (DEC) are recognized, namely enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC), enteroinvasive E. coli (EIEC), enteroaggregative E. coli (EAEC), and enterohemorrhagic E. coli (EHEC). Due to the need for costly and labor-intensive diagnostic procedures, identification of DEC is difficult at standard laboratories. Therefore, the epidemiology of DEC infections remains obscure in Taiwan. Recently, polymerase chain reaction (PCR) or dot blot has been used for genetic detection of DEC. In this study, we analyzed 150 E. coli isolates from diarrheal stools of children under 5 years old. The PCR tests detected 5 ETEC (3.3%), 6 EPEC (4%), 4 EIEC (2.7%), and 13 EAEC (8.7%) isolates. No EHEC was detected. Dot blot and sequence analysis were used to confirm the results of PCR. The cellular fatty acid (CFA) profiles from E. coli isolates were also analyzed. Comparison of CFA composition revealed minor variation in the percentage of each fatty acid detected among DEC isolates of ETEC, EPEC, EIEC and EAEC, but did not provide enough evidence for differentiating between categories of DEC by CFA profiles alone.
Teng
Lee-Jene
LJ
Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan, ROC.
Hsueh
Po-Ren
PR
Liaw
Shwu-Jen
SJ
Ho
Shen-Wu
SW
Tsai
Jui-Chang
JC
D001483:Base Sequence; D002675:Child, Preschool; D003967:Diarrhea / Q000453:epidemiology / Q000382:microbiology; D004926:Escherichia coli / Q000737:chemistry / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology; D005227:Fatty Acids / Q000032:analysis; D006801:Humans; D015151:Immunoblotting; D007223:Infant; D007231:Infant, Newborn; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013624:Taiwan / Q000453:epidemiology
D005227:Fatty Acids