Antibody Selection for Immobilizing Living Bacteria

Abstract

We report a comparative study of the efficacy of immobilizing living bacteria by means of seven antibodies against bacterial surface antigens associated with Salmonella enterica Serovar Typhimurium. The targeted bacterial antigens were CFA/I fimbriae, flagella, lipopolysaccharides (LPS) and capsular F1 antigen. The best immobilization of S. Typhimurium was achieved with the antibody against CFA/I fimbriae. The immobilization of bacteria using anti-flagellin showed significant enhancement if the flagella rotary motion was paralyzed. Of the four antibodies targeting LPS structures, only one, the antibody against the O-antigen polysaccharides, showed a relatively efficient bacterial immobilization. No bacterial immobilization was achieved using the antibody against F1 antigen, presumably because F1 protein can detach from the bacterial surface easily. The results suggest that an antibody for bacterial immunoimmobilization should target a surface antigen which extends out from the bacterial surface and is tightly attached to the bacterial cell wall. The microarrays of living S. Typhimurium cells immobilized in this manner remained viable and effective for at least two weeks in growth medium before a thick biofilm covered the whole surface.

Immunoimmobilization of Living Salmonella for Fundamental Studies and Biosensor Applications

“…This fact enables organisms to maintain their usual bioactivities, while giving rise to secondary activities triggered by the process of immobilization. We have seen evidence of such activity in the excessive production of flagella by bound bacteria as compared to that of the planktonic variety of the same bacteria (Suo et al 2009a). Below we give some examples of the bioactivities of immobilized bacteria.…”

“…3C,D), although with a relatively low cell density as compared with CFA/I fimbriae. In spite of the fact that anti-flagellin shows a reasonably strong affinity to purified S. Typhimurium flagella (data not shown), the coverage density of H647 could not be improved by increasing the incubation time (Suo et al 2009a). We speculate that the low cell coverage density of H647 is a result of the high-speed rotary motion of the flagella, which can be as high as 10,000 rpm at 35°C (Magariyama et al 2001), hindering antibody-antigen interactions.…”

“…We have evaluated the immobilization efficiencies of IgG antibodies against four different types of surface antigens of S. Typhimurium and E. coli: lipopolysaccharides (LPS), flagella, fimbriae, and a capsular protein (Suo et al 2009a). The results show that, with the exception of the capsular protein, all the surface antigens tested can in principle be targeted to achieve some degree of immobilization and that the immobilization efficiency is correlated to multiple factors, especially to the choice of antibody-antigen pairs.…”

Micro-magnet arrays for specific single bacterial cell positioning

“…This approach typically relies on specific antibody-antigen interactions [26]. Such surface-chemistry based patterning methods have proven efficient for arraying individual cells of particular species on a substrate [26,27]. However, cells cannot be easily released from the traps if required and this approach often involves advanced surface chemistry steps, possibly difficult to implement.…”

Surface functionalisation of TiO2 evanescent waveguide sensor for E.coli monitoring

“…Physical adsorption is very sensitive to environmental condition and the second method is very stable due to the creation of covalent bonds during functionalisation [1]. The most common methods used for chemical immobilisation are antibody [2][3][4][5][6][7] and polymerase chain reaction (PCR) [8][9][10][11][12][13].…”