ABSTRACT
The tragic COVID-19 pandemic, which has seen a total of 655 million cases worldwide and a death toll of over 6.6 million seems finally tailing off. Even so, new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to arise, the severity of which cannot be predicted in advance. This is concerning for the maintenance and stability of public health, since immune evasion and increased transmissibility may arise. Therefore, it is crucial to continue monitoring antibody responses to SARS-CoV-2 in the general population. As a complement to polymerase chain reaction tests, multiplex immunoassays are elegant tools that use individual protein or peptide antigens simultaneously to provide a high level of sensitivity and specificity. To further improve these aspects of SARS-CoV-2 antibody detection, as well as accuracy, we have developed an advanced serological peptide-based multiplex assay using antigen-fused peptide epitopes derived from both the spike and the nucleocapsid proteins. The significance of the epitopes selected for antibody detection has been verified by in silico molecular docking simulations between the peptide epitopes and reported SARS-CoV-2 antibodies. Peptides can be more easily and quickly modified and synthesized than full length proteins and can, therefore, be used in a more cost-effective manner. Three different fusion-epitope peptides (FEPs) were synthesized and tested by enzyme-linked immunosorbent assay (ELISA). A total of 145 blood serum samples were used, compromising 110 COVID-19 serum samples from COVID-19 patients and 35 negative control serum samples taken from COVID-19-free individuals before the outbreak. Interestingly, our data demonstrate that the sensitivity, specificity, and accuracy of the results for the FEP antigens are higher than for single peptide epitopes or mixtures of single peptide epitopes. Our FEP concept can be applied to different multiplex immunoassays testing not only for SARS-CoV-2 but also for various other pathogens. A significantly improved peptide-based serological assay may support the development of commercial point-of-care tests, such as lateral-flow-assays.
ABSTRACT
Background: Retention of basic biomedical sciences knowledge is of great importance in medical practice. This study aimed to provide some insights into medical interns' ability to recall theoretical knowledge of medical microbiology and to explore factors that affect its retention. Methods: In this cross-sectional study conducted between January and March 2019, an anonymized questionnaire with 10 validated multiple-choice questions about medical microbiology was distributed as hard copies to test the ability to recall knowledge of Saudi medical interns in three tertiary training hospitals in Riyadh, Saudi Arabia. Results: A total of 300 medical interns [164 females (54.7%) and 136 males (45.3%)], in three major tertiary medical care centers in Riyadh, Saudi Arabia, voluntarily participated in the study. Almost a third of participants, 107 (36.4%), graduated from medical schools adopting a traditional curriculum, whereas 184 (63.6%) graduated from medical schools adopting problem-based learning (PBL) instructional approach. The overall mean score out of 10 marks was 3.9±1.8 with almost 82% failures scoring less than six marks. Both total and pass/fail grades were significantly associated with interns who graduated from private colleges. Scores were not significantly associated with any of the investigated parameters except type of college (governmental vs private) with a p-value of 0.049. Conclusion: The current study revealed an overall poor recall of knowledge in microbiology among interns. Our findings suggest a need for a careful revision of curriculum to correct deficiencies, particularly in teaching medical microbiology. Integration of basic sciences is required as well as aligning teaching of basic medical sciences with clinical skills.