Pathology, virulence-associated gene profiling, antimicrobial susceptibility, and pathogenicity of untypeable capsular serotypes of Pasteurella multocida isolated from slaughtered pigs of India.

Pasteurella multocida is widely distributed in all pig-rearing countries, affecting the economic viability and profitability of pig production. The present research highlights the molecular characterization and pathology of untypeable capsular serotypes of P. multocida in slaughtered pigs from prominent pig-rearing states of India. The prevalence of Pasteurellosis was 27.17% by Pasteurella multocida specific Pasteurella multocida specific PCR (PM-PCR). assay, while isolation rate was 7.62%. The microscopic lesions of bronchopneumonia, tonsillitis, and the presence of bacterial antigens in immunohistochemistry confirmed P. multocida with pathologies. In capsular typing, the majority of the isolates were untypeable with prevalence of 52.15% and 43.58% in molecular and microbiological methods, respectively. All the isolates showed the uniform distribution of virulence genes such as exbB, nanB, sodC, plpB, and oma87 (100%), while the variations were observed in ptfA, hasR, ptfA, pfhA, hsf-1, and plpE genes. The untypeable isolates showed higher prevalence of hsf-1 gene as compared to others. The untypeable serotypes showed a higher degree of resistance to ampicillin, amoxicillin, and penicillin antibiotics. The mouse pathogenicity testing of untypeable capsular isolates confirmed its pathogenic potential. The higher frequency of pathogenic untypeable isolates with antibiotic resistance profile might pose a serious threat to the pigs, and therefore, preventive measures should be adopted for effective control.

SARS-CoV-2 Spike Protein Extrapolation for COVID Diagnosis and Vaccine Development.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) led to coronavirus disease 2019 (COVID-19) pandemic affecting nearly 71.2 million humans in more than 191 countries, with more than 1.6 million mortalities as of 12 December, 2020. The spike glycoprotein (S-protein), anchored onto the virus envelope, is the trimer of S-protein comprised of S1 and S2 domains which interacts with host cell receptors and facilitates virus-cell membrane fusion. The S1 domain comprises of a receptor binding domain (RBD) possessing an N-terminal domain and two subdomains (SD1 and SD2). Certain regions of S-protein of SARS-CoV-2 such as S2 domain and fragment of the RBD remain conserved despite the high selection pressure. These conserved regions of the S-protein are extrapolated as the potential target for developing molecular diagnostic techniques. Further, the S-protein acts as an antigenic target for different serological assay platforms for the diagnosis of COVID-19. Virus-specific IgM and IgG antibodies can be used to detect viral proteins in ELISA and lateral flow immunoassays. The S-protein of SARS-CoV-2 has very high sequence similarity to SARS-CoV-1, and the monoclonal antibodies (mAbs) against SARS-CoV-1 cross-react with S-protein of SARS-CoV-2 and neutralize its activity. Furthermore, in vitro studies have demonstrated that polyclonal antibodies targeted against the RBD of S-protein of SARS-CoV-1 can neutralize SARS-CoV-2 thus inhibiting its infectivity in permissive cell lines. Research on coronaviral S-proteins paves the way for the development of vaccines that may prevent SARS-CoV-2 infection and alleviate the current global coronavirus pandemic. However, specific neutralizing mAbs against SARS-CoV-2 are in clinical development. Therefore, neutralizing antibodies targeting SARS-CoV-2 S-protein are promising specific antiviral therapeutics for pre-and post-exposure prophylaxis and treatment of SARS-CoV-2 infection. We hereby review the approaches taken by researchers across the world to use spike gene and S-glycoprotein for the development of effective diagnostics, vaccines and therapeutics against SARA-CoV-2 infection the COVID-19 pandemic.