Shiga toxin assay

Later, Suri Iyer et al. synthesized similar Gb3-AuNPs but with different length of linkers and surface glycan densities [66], They conducted luciferase assay to measure the toxin-mediated inhibition of protein synthesis and found that Gb3-AuNPs were nontoxic to Vero monkey kidney cells and protected Vero cells from Shiga toxin in a dose-dependent manner. 

However, the presence of cytotoxicity in the extract could be due to other toxins or bacterial products, it is necessary to perform a neutralization assay with specific antisera to confirm that the cytopathic effect is due to the production of Shiga toxins. Moreover, in absence of neutralization assay, VGA lacks specificity (Rahn et al. 1996). Therefore, the Vero Cells assay have been largely supplanted by immunologically-based and DNA-based method for the detection of STEC, but is still used for confirmation of Shiga toxin production from pure cultures. 

Kehl KS, Havens P, Behnke CE, Acheson DW (1997) Evaluation of the premier EHEC assay for detection of Shiga toxin-producing Escherichia coli. J Clin Microbiol 35 2051-2054 Konowalchuk J, Speirs Jl, Stavric S (1977) Vero response to a cytotoxin of Escherichia coli. Infect Immun 18 775-779... 

Reischl U, Youssef MT, Kilwinski J, Lehn N, Zhang WL, Karch H, Strockbine NA (2002) Realtime fluorescence PCR assays for detection and characterization of Shiga toxin, intimin, and enterohemolysin genes from Shiga toxin-producing Escherichia coli. J Clin Microbiol 40 2555-2565... 

Cebula TA, Payne WL, Feng P (1995) Simultaneous identification of strains of Escherichia coli serotype 0157 H7 and their Shiga-hke toxin type by mismatch amphfication mutation assay-multiplex PCR. J Chn Microbiol 33 248-250... 

BAB 14] Babu U.S., Gaines D.M., Wu Y. et al., Use of flow cytometry in an apoptosis assay to determine pH and temperature stabihty of shiga-like toxin 1 ,... 

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