Abstract #M65
Section: Animal Health (posters)
Session: Animal Health I
Format: Poster
Day/Time: Monday 7:30 AM–9:30 AM
Location: Exhibit Hall A
Session: Animal Health I
Format: Poster
Day/Time: Monday 7:30 AM–9:30 AM
Location: Exhibit Hall A
# M65
Development of antibody-conjugated chitosan microparticles selectively targeting Shiga toxin producing Escherichia coli in the gastrointestinal tract.
Zhengxin Ma*1,2, Minyoung Kang1,2, Shanyu Meng3, Zhaohui Tong3, Adegbola Adesogan1, Kwangcheol Jeong1,2, 1Department of Animal Sciences, University of Florida, Gainesville, FL, 2Emerging Pathogens Institute, University of Florida, Gainesville, FL, 3Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL.
Key Words: chitosan microparticles, Shiga toxin-producing Escherichia coli
Development of antibody-conjugated chitosan microparticles selectively targeting Shiga toxin producing Escherichia coli in the gastrointestinal tract.
Zhengxin Ma*1,2, Minyoung Kang1,2, Shanyu Meng3, Zhaohui Tong3, Adegbola Adesogan1, Kwangcheol Jeong1,2, 1Department of Animal Sciences, University of Florida, Gainesville, FL, 2Emerging Pathogens Institute, University of Florida, Gainesville, FL, 3Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL.
The objective of this study was to develop anti-Shiga toxin-producing Escherichia coli (STEC) antibody conjugated chitosan microparticles (CM) to control STEC at the pre-harvest level. STEC are important foodborne pathogens, and cattle are the major reservoirs. Several methods have been tried to reduce these pathogens at the pre-harvest level. However, the trials have not been successful. CM, derived from chitosan, have shown great broad-spectrum antimicrobial activity. Here, we report that conjugation of CM and anti-STEC IgY antibodies kill STEC selectively. Lipopolysaccharides (LPS) of 7 STEC serotypes (O26, O45, O103, O111, O121, O145, and O157) were extracted by phenol-water extraction and purified with high performance liquid chromatography (HPLC). Five laying hens were immunized with each LPS respectively, and IgY antibodies were purified from egg yolk. The sensitivity and specificity of IgY were tested by ELISA. The detection limit of IgY ranged between 2 and 3 log cfu/well. Five out of 7 types of anti-STEC IgY were able to recognize the corresponding STEC serotype selectively. CM and the antibodies were linked by stable covalent amide bonds at 10:1, 10:2, and 10:4 ratios respectively. The activity of anti-O157 CM-IgY and CM at 0.05% were examined against E. coli O157:H7, S. enterica and their combination. Data were analyzed using the GLM procedure of SAS and a statistical model that included different treatments was generated. Compared with CM, CM-IgY (10:2) showed significantly stronger activity against E. coli O157 (P < 0.05), indicating that IgY enhanced the specificity of CM. When the CM and CM-IgY were applied to only S. enterica, no significant difference was found in the bacterial inhibition (P > 0.1). In a mixed culture of both bacteria, CM-IgY conjugates decreased the concentration of E. coli O157 significantly compared with CM (P < 0.05), but did not affect the concentration of S. enterica. The same selective activity was maintained in synthetic intestinal fluid and a mixed culture of E. coli O157 and Lactobacillus plantarum. These results suggested that the CM-IgY conjugates have strong specific antimicrobial activity, and are great candidates to eliminate pathogens selectively in the gastrointestinal tract of animals.
Key Words: chitosan microparticles, Shiga toxin-producing Escherichia coli
