Biology subjects
Publications and source records attributed to Malik, Y. S..
In 2015, a novel highly divergent bovine calicivirus was detected in an Indian calf with enteritis. Phylogenetic analysis linked it to the Nebovirus with only 38.5% sequence identities, emphasizing the need for separate taxonomic classification. Furthermore, PCR screening detected these unique caliciviruses widely in Indias northern states.
Understanding the origin of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a highly debatable and unsolved challenge for the scientific communities across the world. A key to dissect the susceptibility profiles of animal species to SARS-CoV-2 is to understand how virus enters into the cells. The interaction of SARS-CoV-2 ligands (RBD on spike protein) with its host cell receptor, angiotensin-converting enzyme 2 (ACE2), is a critical determinant of host range and cross-species transmission. In this study, we developed and implemented a rigorous computational approach for predicting binding affinity between 299 ACE2 orthologs from diverse vertebrate species and the SARS-CoV-2 spike protein. The findings show that the spike protein of SARS-CoV-2 can bind to many vertebrate species carrying evolutionary divergent ACE2, implying a broad host range at the virus entry level, which may contribute to cross-species transmission and further viral evolution. Additionally, the present study facilitated the identification of genetic determinants that may differentiate susceptible from the resistant host species based on the conservation of ACE2-spike protein interacting residues in vertebrate host species known to facilitate SARS-CoV-2 infection; however, these genetic determinants warrant in vivo experimental confirmation. The molecular interactions associated with varied binding affinity of distinct ACE2 isoforms in a specific bat species were identified using protein structure analysis, implying the existence of diversified susceptibility of bat species to SARS-CoV-2. The findings from current study highlight the importance of intensive surveillance programs aimed at identifying susceptible hosts, particularly those with the potential to transmit zoonotic pathogens, in order to prevent future outbreaks.
We provide a novel single restriction enzyme (RE) (BsaHI) digestion approach for detecting distinct pathotypes of the Newcastle disease virus (NDV). After scanning 4000 F gene nucleotide sequences in the NCBI database, a single RE (BsaHI) digesting site was discovered in the cleavage site. APMV-I "F gene" Class II specific primer-based reverse transcriptase PCR (RT-PCR) was utilized to amplify a 535 bp fragment, which was then digested with a single RE (BsaHI) for pathotyping avian NDV field isolates and pigeon paramyxovirus-1 isolates. The avirulent (lentogenic and mesogenic strains) produce 189 and 346 bp fragments, respectively, but the result in velogenic strains remains undigested with 535 bp fragments. In addition, 45 field NDV isolates and 8 vaccine strains were used to confirm the approach. The sequence-based analysis also agrees with the data obtained utilizing the single RE (BsaHI) digestion approach. The proposed technique had the potential to distinguish between avirulent and virulent strains in a short space of time, making it valuable in NDV surveillance and monitoring research.
The present study reports the detection and molecular characterization of rotavirus A (RVA), rotavirus D (RVD), rotavirus F (RVF), rotavirus G (RVG) and picobirnavirus (PBV) in fecal specimens of wild and exotic birds (n = 23) from different cities of Para state, which were hospitalized at Veterinary Hospital of the Federal University of Para, Brazil, between January 2018 to June 2019. The animals exhibited different clinical signs, such as diarrhea, malnutrition, dehydration and fractures. The results showed 39.1% (9/23) of positivity for RVA by RT-qPCR. Among these, one sample (1/9) for the NSP3 gene of T2 genotype was characterized. About 88.9% (8/9) for the VP7 gene belonging to G1, equine-like G3 and G6 genotypes, and 55.5% (5/9) for the VP4 gene of P[2] genotype were obtained. In the current study, approximately 4.5% of the samples (1/23) revealed coinfection for the RVA, RVD and RVF groups. Furthermore, picobirnavirus (PBV) was detected in 1 of the 23 samples tested and was classified in the Genogroup I. The findings represent the first report of the circulation of RVA, RVD, RVF, RVG and PBV genotypes in wild birds in Brazil and suggest the possible interspecies transmission of RVs and PBVs.