Primary fecal culture used as template for PCR detection of diarrheagenic E. coli virulence factors.
The PCR technique applied to primary fecal cultures (PFC-PCR) was compared to the usual method employing isolated colonies (IC-PCR) in order to assess its sensitivity in the detection of virulence markers of diarrheagenic Escherichia coli in fecal samples obtained from children with diarrhea. Among the 149 samples analysed, PFC-PCR detected 81(54.4%) samples presenting one or two virulence markers, while IC-PCR detected only 59 (39.6%) positive samples. The markers detected in order of frequency were: pAA, LT-I, eaeA, ST-I, daaE, and ipaH. The PFC-PCR method of detection of diarrheagenic E. coli virulence markers proved to be reliable and more sensitive (p<0.05) than the usual method employing isolated colonies. It has also the advantage of being faster and less expensive than the detection methods in current use.
da Silva Duque
Sheila
S
Departamento de Bacteriologia, Instituto Oswaldo Cruz-FIOCRUZ, Av. Brasil 4365, 21045-900, RJ, Rio de Janeiro, Brazil.
Silva
Rosa Maria
RM
Sabra
Aderbal
A
Campos
Leila Carvalho
LC
D002675:Child, Preschool; D004926:Escherichia coli / Q000302:isolation & purification / Q000472:pathogenicity*; D005243:Feces / Q000382:microbiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016133:Polymerase Chain Reaction / Q000379:methods*; D014774:Virulence