The isolation of K99 Escherichia coli (K99 E. coli) was performed using diarrheal stool which occurred in calves from january through October, 1988. Moreover, bacteriolgical examination of isolated K99 E. coli and the adherent condition of K99 antigen in the intestinal canal of a dead calf was observed. In addition an epidemiological survey mainly including antibody examination of adult cattle ...

Neonatal pigs were inoculated with porcine enterotoxigenic Escherichia coli 431, which carries genes for K99 fimbriae and STaP enterotoxin. Colonies of strain 431 were recovered from feces of pigs for up to 17 days after inoculation and tested for hybridization with gene probes for K99 and STaP. Variants of strain 431 that did not hybridize with the probes were considered to have lost the genes...

Escherichia coli (E. coli) strains were collected from young diarrheic calves in farms and field. Strains that expressed the K99 (F5) antigen were identified by agglutination tests using reference antibodies to K99 antigen and electron microscopy. The K99 antigen from a selected field strain (SAR-14) was heat-extracted and fractionated on a Sepharose CL-4B column. Further purification was carri...

The production of the K99 antigen by enterotoxigenic Escherichia coli strains with various O antigens was investigated by means of slide agglutination tests, enzyme-linked immunosorbent assays, and hydrophobic interaction chromatography. The extent of K99 production appeared to be dependent on the nutrient medium, as well as on the incubation temperature. Minimal salt medium with glucose and se...

A spontaneously occurring field isolate of enterotoxigenic Escherichia coli that was genotypically K99+ but phenotypically K99- was analyzed for the reason that it did not express K99. The defect, which was cis active, was located within an area 5' to the first gene required for K99 biogenesis and was the result of the deletion of a single base pair.

Sufficient history now exists to assess the National Institutes of Health Pathway to Independence Award (K99/R00), first offered in 2007 to support the career development of biomedical researchers. The success of K99 (Mentored Phase of the K99/R00) principal investigators in obtaining subsequent grant support was compared with that of principal investigators supported by the long-standing K08 (...

The isoelectric point of the K99 antigen in partially purified preparations isolated from Escherichia coli B41 was 4.2. Electrofocused K99 antigen hemagglutinated guinea pig and sheep erythrocytes and gave a single precipitin line on diffusion against antisera to E. coli B41 and absorbed factor K99 antisera.

Pregnant cattle were either vaccinated subcutaneously with (i) a suspension of purified Escherichia coli K99 pili, (ii) a Formalin-killed whole cell bacterin containing enterotoxigenic E. coli strain B44 (O9:K30;K99:H-), or (iii) a bacterin containing six different strains of bovine enterotoxigenic E. coli (multiple-strain bacterin), or were left as nonvaccinated controls. After birth, calves w...