Development of multiplex polymerase chain reaction assays for detecting enterotoxigenic Escherichia coli and their application to field isolates from piglets with diarrhea.
Fimbriae and enterotoxins are major virulence factors associated with enterotoxigenic Escherichia coli (ETEC). In this study, 3 sets of multiplex polymerase chain reaction (mPCR) assays targeting fimbriae, enterotoxins, and other adherence factors were developed for detecting ETEC. A total number of 188 E. coli field isolates were examined, and percentages of E. coli strains carrying each virulence factors were as follows: F4 (7.45%), F5 (29.79%), F6 (6.38%), F18 (15.43%), F41 (3.72%), STa (10.11%), STb (20.74%), LT (9.57%), Stx2e (2.13%), EAST1 (42.02%), F1 (67.55%), AIDA-I (2.66%), and pAA (7.45%). Of the 188 E. coli field isolates examined, 25.53% were found to be pathogenic ETEC, having both fimbriae and enterotoxins. However, the ratio increased to 44.68% when the presence of other adhesins was considered as criteria for virulence. Among the adherence factors, F1 was found to be the most prevalent. AIDA-I and pAA were also found with similar ratio as compared with other virulence factors. In addition, virulence patterns carrying these alternate adhesive genes with enterotoxins were detected with significant ratio. Therefore, it is desirable that alternate adhesins be considered as markers for diagnosis of ETEC.
Lee
Su In
SI
Department of Infectious Disease, College of Veterinary Medicine, Seoul National University, Seoul, South Korea.
Kang
Sang Gyun
SG
Kang
Mi Lan
ML
Yoo
Han Sang
HS
D000818:Animals; D003967:Diarrhea / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D054307:Enterotoxigenic Escherichia coli / Q000235:genetics / Q000302:isolation & purification*; D004768:Enterotoxins / Q000235:genetics / Q000378:metabolism; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D036781:Fimbriae Proteins / Q000235:genetics / Q000378:metabolism; D007723:Korea / Q000453:epidemiology; D016133:Polymerase Chain Reaction / Q000662:veterinary*; D012680:Sensitivity and Specificity; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology*
D004768:Enterotoxins; D036781:Fimbriae Proteins