title: Development of a monoclonal antibody-based co-agglutination test to detect enterotoxigenic Escherichia coli isolated from diarrheic neonatal calves.
abstract: 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 carried out by sodium deoxycholate treatment and/or ion-exchange chromatography. Monoclonal antibodies to purified K99 antigen were produced by the hybridoma technique, and a specific clone, NEK99-5.6.12, was selected for propagation in tissue culture. The antibodies, thus obtained, were affinity-purified, characterized and coated onto Giemsastained Cowan-I strain of Staphylococcus aureus (S. aureus). The antibody-coated S. aureus were used in a coagglutination test to detect K99+ E. coli isolated from feces of diarrheic calves. The specificity of the test was validated against reference monoclonal antibodies used in co-agglutination tests, as well as in ELISA. Specificity of the monoclonal antibodies was also tested against various Gram negative bacteria. The developed antibodies specifically detected purified K99 antigen in immunoblots, as well as K99+ E. coli in ELISA and co-agglutination tests. The co-agglutination test was specific and convenient for large-scale screening of K99+ E. coli isolates.
authors.affiliation: Intas Biopharmaceuticals Ltd., Plot No. 423/P/A/GIDC, Sarkhej-Bavla Highway, Moraiya, Ahmedabad-382 210, Gujarat, India. brajesh.varshney@intasbiopharma.co.in
authors.forename: Brajesh C
authors.initials: BC
authors.lastname: Varshney
authors.forename: N M
authors.initials: NM
authors.lastname: Ponnanna
authors.forename: Pranati A
authors.initials: PA
authors.lastname: Sarkar
authors.forename: Pragna
authors.initials: P
authors.lastname: Rehman
authors.forename: Jigar H
authors.initials: JH
authors.lastname: Shah
mesh_terms: D000372:Agglutination Tests / Q000379:methods / Q000662:veterinary*; D000818:Animals; D000831:Animals, Newborn; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology / Q000302:isolation & purification; D001427:Bacterial Toxins / Q000276:immunology / Q000302:isolation & purification; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology* / Q000382:microbiology*; D002850:Chromatography, Gel / Q000662:veterinary; D002852:Chromatography, Ion Exchange / Q000662:veterinary; D002853:Chromatography, Liquid / Q000662:veterinary; D003967:Diarrhea / Q000276:immunology / Q000662:veterinary*; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D004926:Escherichia coli / Q000276:immunology*; D004927:Escherichia coli Infections / Q000276:immunology / Q000662:veterinary*; D015151:Immunoblotting / Q000662:veterinary; D013211:Staphylococcus aureus
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D001427:Bacterial Toxins; C031429:K99 antigen