Development & validation of a quantitative anti-protective antigen IgG enzyme linked immunosorbent assay for serodiagnosis of cutaneous anthrax

Abstract

Background & objectives:Anthrax caused by Bacillus anthracis is primarily a disease of herbivorous animals, although several mammals are vulnerable to it. ELISA is the most widely accepted serodiagnostic assay for large scale surveillance of cutaneous anthrax. The aims of this study were to develop and evaluate a quantitative ELISA for determination of IgG antibodies against B. anthracis protective antigen (PA) in human cutaneous anthrax cases.Methods:Quantitative ELISA was developed using the recombinant PA for coating and standard reference serum AVR801 for quantification. A total of 116 human test and control serum samples were used in the study. The assay was evaluated for its precision, accuracy and linearity.Results:The minimum detection limit and lower limit of quantification of the assay for anti-PA IgG were 3.2 and 4 µg/ml, respectively. The serum samples collected from the anthrax infected patients were found to have anti-PA IgG concentrations of 5.2 to 166.3 µg/ml. The intra-assay precision per cent CV within an assay and within an operator ranged from 0.99 to 7.4 per cent and 1.7 to 3.9 per cent, respectively. The accuracy of the assay was high with a per cent error of 6.5 - 24.1 per cent. The described assay was found to be linear between the range of 4 to 80 ng/ml (R2=0.9982; slope=0.9186; intercept = 0.1108).Interpretation & conclusions:The results suggested that the developed assay could be a useful tool for quantification of anti-PA IgG response in human after anthrax infection or vaccination.

The Humoral Immune Response to Various Domains of Protective Antigen of Bacillus anthracis in Cutaneous Anthrax Cases in India

“…The patients were clinically and epidemiologically well-defined. The serum samples were confirmed for the presence of anti-PA IgG in the previous studies 23 .…”

“…A total of 43 serum samples from clinically proved cutaneous anthrax patients from the anthrax endemic area were selected in this study 22,23 . The patients were clinically and epidemiologically well-defined.…”

Development of Enzyme Linked Immunosorbent Assay for humoral immuneresponse and infection monitoring of anthrax

“…The average OD was calculated for each sample and at the end, the antibody was reported by EU/mL for each sample. The results of OD were assessed by %CV (SD/mean×100) (Ghosh et al, 2015).…”

“…The LOD was estimated by interpolating the mean of all 68 OD values, plus standard deviations. The LOD was calculated by the following formula: Mean (OD) + 3SD; then, it was reported in EU/mL (Ghosh et al, 2015).…”

A Rapid Flow through Membrane Enzyme Linked Immunosorbent Assay for Bacillus anthracis using Surface Array Protein as a Biomarker

“…Conventionally, B. anthracis is confirmed by culture followed by Gram or capsule staining 21 . There are several serodiagnostic assays for anthrax infection in humans [22][23][24][25] . However, sophisticated tools and techniques are required for its detection from the environmental or clinical samples 20,26,27 .…”