Expression of P, S, and F1C adhesins by cytotoxic necrotizing factor 1-producing Escherichia coli from septicemic and diarrheic pigs.
Nineteen papC-positive cytotoxic necrotizing factor 1 (CNF1)-producing Escherichia coli isolates from pigs with septicemia or diarrhea were tested for the presence of pap-, sfa-, and afa-related sequences encoding P/Prs, S/F1C, and Dr/AFA adhesins respectively. Production of adhesins by isolates was tested by mannose-resistant hemagglutination (MRHA), sialidase treatment of erythrocytes and particle agglutination tests. Production of P, S, and F1C fimbriae by isolates was also examined by immunofluorescence. All isolates were pap+ by PCR. Eighteen isolates (95%) were MRHA for ovine and human A erythrocytes and exhibited GalNac-GalNac receptor specificity associated with class III P(Prs) adhesins. Fifteen (79%) of the 19 isolates reacted with antisera specific for one or more different P fimbrial serotypes on immunofluorescence. Three of these isolates also demonstrated Gal-Gal receptor specificity associated with class I or II P fimbrial adhesins. Fifteen (79%) of the isolates were sfa+ by PCR. Seven of these isolates exhibited sialidase-sensitive MRHA of bovine and human O erythrocytes and reacted with serum specific for S fimbriae on immunofluorescence. Seven of the 8 sfa+ isolates which were MRHA-negative for bovine erythrocytes reacted with serum specific for F1C fimbriae on immunofluorescence. All isolates produced type 1 fimbriae as determined by mannose-sensitive agglutination of yeast cells. None of the isolates were afa+ by PCR or colony hybridization. Results suggest that most pap+ porcine CNF1-producing E. coli isolates express P fimbriae bearing class III (Prs) type adhesins. In addition, most of these isolates also produce S or F1C fimbriae.
Dozois
C M
CM
GREMIP, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Qué, Canada.
Clément
S
S
Desautels
C
C
Oswald
E
E
Fairbrother
J M
JM
D018829:Adhesins, Bacterial / Q000032:analysis*; D000372:Agglutination Tests / Q000379:methods; D000818:Animals; D001427:Bacterial Toxins / Q000633:toxicity*; D002417:Cattle; D003603:Cytotoxins / Q000633:toxicity*; D003967:Diarrhea / Q000382:microbiology*; D004912:Erythrocytes; D004926:Escherichia coli / Q000737:chemistry / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins; D010861:Fimbriae, Bacterial / Q000378:metabolism; D006801:Humans; D018805:Sepsis / Q000382:microbiology*; D012756:Sheep; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology
D018829:Adhesins, Bacterial; D001427:Bacterial Toxins; D003603:Cytotoxins; D029968:Escherichia coli Proteins; C060296:cytotoxic necrotizing factor type 1