Serological survey to detect antigens that cross-react with COVID-19 antibodies

Ahmed N. Mnahi, Basrah children specialty hospital, Basrah health directorate, Basrah, Iraq.Follow
Abdulelah A. Almyah, Department of clinical laboratory science, college of pharmacy, university of Basrah, Basrah, Iraq.Follow
Zuhair AL-Shaheen, Department of clinical laboratory science, college of pharmacy, university of Basrah, Basrah, Iraq.Follow

Article Type

Original Study

Abstract

Background: COVID-19 first emerged in Wuhan City and has since spread worldwide, infecting over 600 million people. The World Health Organization (WHO) issued an emergency in public health in January 2020 due to reports of new coronaviruses in Europe, Asia, and the Americas. Aim: The study aims to screen bacterial antigens for cross-reactivity with COVID-19 antibodies using indirect ELISA and to detect cross-reactivity between vaccinated and unvaccinated healthy individuals and various bacterial types (Gammaproteobacteria, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, and Enterobacteria, in addition to Staphylococcus aureus) either sonicated or non-sonicated. Methods: ELISA is a method for detecting unknown samples in a sample. It involves pipetting 50 μl of diluted antigen dilution into PVC microtiter plates, with pure antigen test samples pipetted at 2 µg/ml. The plate is incubated at room temperature for 2 hours or overnight at 4°C. Blocking is done with 200 μl of blocking buffer. The plate is then incubated overnight at 4°C or room temperature for 2 hours. Primary and secondary antibody incubation is performed, with two hours of room-temperature incubation and overnight incubation for stronger staining. Absorbance is measured for each well, and the results can be analyzed using a standard curve. Results: Results showed that vaccinated individuals had highly significant p-values of IgG antibodies against S. aureus, Pseudomonas aeruginosa, Enterobacteria, and Bacillus, while unvaccinated individuals had non-significant p values. Conclusions: The high cross-reactivity identified E. coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Enterobacteria, and Gammaproteobacteria. The current study was validated by the discovery of a significant correlation between Pfizer vaccinated individual's serum antibodies and unvaccinated individual's serum and the examined bacterial antigens that had a high titer of cross-reactivity with the vaccinated samples in comparison to the unvaccinated samples (less titer).

Keywords

COVID-19, ELISA, bacterial antigens, vaccinated and unvaccinated individuals

Recommended Citation

Mnahi, Ahmed N.; Almyah, Abdulelah A.; and AL-Shaheen, Zuhair (2024) "Serological survey to detect antigens that cross-react with COVID-19 antibodies," Iraqi National Journal of Medicine: Vol. 6 : Iss. 1 , Article 8.
Available at: https://doi.org/10.37319/