[Four serotypes highly positive for pathogenic factor-related genes found among Escherichia coli isolates from sporadic diarrheal cases in Fukui Prefecture].
To evaluate the prevalence of pathogenic factor-related genes in 964 O-serotype Escherichia coli isolated from sporadic diarrhea cases at 2 hospitals in Fukui during 1997 to 2001, we checked all of these strains for H-serotype and examined them for 4 pathogenic factor-related genes (LT, ST, stx and invE) by PCR. Of these strains, 409 except for most of 9 serotypes which are usually low prevalence of pathogenic factor-related genes, and additional 16 strains isolated from other hospitals in Fukui Prefecture were also examined for 3 pathogenic factor-related genes (eaeA, astA and aggR) by PCR. It was found that 4 serotypes, O6:H16, O25:HNM, O111:H21 and O126:H27, were highly positive for pathogenic factor-related genes; O6:H16 (11/12 strains) positive for LT, ST, astA, O 25:HNM (10/14 strains) positive for ST and astA, O111:H21 (22/22 strains) positive for astA or aggR, and O126:H27 (8/9) positive for astA and aggR genes. According to the drug susceptibility test, these serotypes as O6:H16, O25:HNM, O111:H21 and O126:H27 showed a significant resistance to some drugs in 7/12, 4/14, 21/22 and 9/9 strains, respectively. Such results indicate that both O111 and O126-serotypes are highly positive for pathogenic factor-related genes and also drug-resistant, namely this fact suggests that the O-serotyping as laboratory screening is one of the useful measures of clinical management. Additionally, the pulsedfied gel electrophoresis patterns found in each of the 4 serotypes mentioned revealed that a part of E. coli in Fukui might be derived from the same source of infection.
Ishiguro
Fubito
F
Fukui Prefectural Institute of Public Health and Environmental Science.
Nakamura
Masako
M
Asada
Tuneo
T
D003967:Diarrhea / Q000382:microbiology; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000145:classification* / Q000235:genetics* / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000382:microbiology*; D006801:Humans; D007564:Japan; D012703:Serotyping