Establishment of three categories of P-fimbriated Escherichia coli strains that show different toxic phenotypes and belong to particular O serogroups.
Eight hundred and nineteen strains of Escherichia coli isolated in Spain between 1986 and 1991 from extraintestinal infections and feces of healthy controls were investigated for expression of P-fimbriae using a particle agglutination test. Among strains causing urinary tract infections, sepsis and other extraintestinal infections, P-fimbriae were found in 31% (130/420) (P < 0.001), 25% (30/118) (P < 0.001) and 12% (11/92) (P < 0.5) respectively. In contrast, only 7% (14/189) of faecal isolates from healthy individuals carried P-fimbriae. According to two more common toxic markers detected in this study (alpha-haemolysin and cytotoxic necrotizing factor type 1), P-fimbriated E. coli strains were grouped into three categories: haemolysin+cytotoxic necrosing factor+ (Hly+CNF1+) (68/185; 37%), haemolysin+cytotoxic necrosing factor- (Hly+CNF1-) (61/185; 33%) and Hly-CNF1- (56/185; 30%). The 185 P-fimbriated strains belonged to 17 different O serogroups. However, 148 (80%) were of one of six serogroups (O1, O2, O4, O6, O7 and O18). The most frequent serogroups determined in the Hly+CNF1+ strains were the O4 and O6 (53/68; 78%), in the Hly+CNF1- strains it was the O18 (27/61; 44%) and in the Hly-CNF1- strains the O1, O2 and O7 (41/56; 73%). The majority (160/185; 86%) of P-fimbriated E. coli expressed the mannose-resistant haemagglutinin type IVa.
Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago, Lugo, Spain.
J
J
Blanco
M P
MP
Alonso
M
M
Blanco
J E
JE
Blanco
E A
EA
González
J I
JI
Garabal
D001427:Bacterial Toxins / Q000096:biosynthesis; D001665:Binding Sites; D002240:Carbohydrate Sequence; D003603:Cytotoxins / Q000096:biosynthesis; D004187:Disaccharides / Q000737:chemistry; D004926:Escherichia coli / Q000145:classification* / Q000302:isolation & purification / Q000472:pathogenicity; D029968:Escherichia coli Proteins; D010861:Fimbriae, Bacterial / Q000378:metabolism; D006386:Hemagglutination Tests; D006459:Hemolysin Factors / Q000096:biosynthesis; D006801:Humans; D008969:Molecular Sequence Data; D010641:Phenotype; D012703:Serotyping; D014774:Virulence
D001427:Bacterial Toxins; D003603:Cytotoxins; D004187:Disaccharides; D029968:Escherichia coli Proteins; C060296:cytotoxic necrotizing factor type 1