A comparative study between first three waves of COVID-19 pandemic with respect to risk factors, initial clinic-demographic profile, severity and outcome.

Introduction: During the 2 years and 9 months from March 2020 to December 2022, the SARS-CoV-2 virus raged across the country. Cases occurred in three particular time clusters recognised by World Health Organisation as coronavirus disease 2019 (COVID-19) waves. In this study, we compare the clinical parameters of adult non-obstetric COVID-19 patients admitted to our rural tertiary care hospital during the three distinct waves of the pandemic. Materials and Methods: Retrospective chart analysis of 272, 853 and 97 patients admitted with SARS-CoV-2 infection to the only rural medical tertiary care centre in the Sunderbans of West Bengal in the first, second and third waves, respectively, was done after obtaining ethical and scientific clearance. Clinical [vital parameters, oxygen requirement, mental status, risk factor assessment, duration of hospital stay, modified-emergency warning score (m-EWS), quick Sequential Organ Failure Assessment (qSOFA), confusion, uraemia, respiratory rate, blood pressure, age ≥ 65 years (CURB65)], epidemiological variables (age, gender, and vaccination status), laboratory parameters and in-hospital outcome were recorded and analysed statistically. Results: Statistically significant (P < 0.05) m-EWS and qSOFA scores were recorded during the second wave of the pandemic. The second wave also recorded the highest mortality (14.89%) compared to the first (12.87%) and third (11.96%) waves, though this was not statistically significant. The highest duration of hospital stay was recorded in the first wave of the pandemic (mean = 9.99 days, P < 0.01). The difference in mortality rates between patients with and without co-morbidity (P < 0.05) was observed during Wave-1, across any pandemic wave, and overall but not in Wave-2 and Wave-3. Conclusion: The second wave of the COVID-19 pandemic was the most severe in comparison with the other two waves, while the outcome was poorer in those with co-morbidities, especially in the first wave.

Genetic diversity, population structure analysis and codon substitutions of Indicine Badri cattle using ddRAD sequencing.

The present study was carried out on 96 animals representing three distinct colour variants of Badri cattle to investigate the genetic diversity, population structure and substitution mutations in the genetic codons due to single nucleotide variations. The DNA samples of 96 Badri cows were genotyped using a double digestion restriction associated DNA (ddRAD) sequencing approach. A standardized bioinformatics pipeline was employed to identify single nucleotide polymorphisms (SNPs), initially detecting 7,168,552 SNPs through alignment with the Bos indicus reference genome assembly. Subsequent stringent quality filtration yielded 65,483 high-confidence SNPs for downstream analysis. Genetic diversity analysis of the Badri cattle population resulted in average values of 0.145, 0.088, and 0.091 for Shannon's diversity Index (I), Simpson's Diversity (h), and Simpson's Unbiased Diversity (uh), respectively. Genetic similarities between the black and brown, black and grey, and brown and grey Badri variants were found to be 0.9972, 0.9980 and 0.9970, respectively. Tajima's D diversity value was observed to be significant and positive for 99.29% of high-confidence SNPs (65,483). STRUCTURE analysis showed admixture among the three Badri colour variants, suggesting a lack of genetic differentiation. Annotation of high-confidence SNPs regarding genetic codon changes indicated maximum substitutions in the GGC with GGT (22 occurrences), followed by AAC to AGC (20 occurrences), GAA to TAA (19 occurrences) and CAA to CAG (19 occurrences). The study concludes there are genetic similarities among colour variants, lack of rare alleles, balancing selection, sudden population contraction and genetic codon substitutions within the Badri cattle population. Insights derived from SNP data analysis hold potential significance for conservation initiatives and breed improvement programs for indicine cattle.

Genome-wide identification and annotation of SNPs and their mapping in candidate genes related to milk production and fertility traits in Badri cattle.

This study was conducted in Badri cattle using a double digest restriction-site associated DNA sequencing approach. The study aimed to identify and annotate high confidence single nucleotide polymorphisms (SNPs) and their mapping in candidate genes related to production and fertility in dairy cattle. A total of 7,168,552 genome-wide SNPs were initially identified in Badri cattle by alignment with the Bos indicus reference genome. After filtration of SNPs, 65,483 high confidence SNPs were retained and further used for downstream analysis. Annotation of high confidence SNPs revealed 99.197% SNPs had modifier impact, 0.326% SNPs were low impact, 0.036% were high impact, and 0.441% were moderate impact SNPs. Most SNPs in Badri cattle were found in intergenic, transcript and intronic regions. The candidate genes for milk production PRKCE, ABCG2, GHR, EPS8, CAST and NRXN1 were found to harbour maximum high confidence variants. Among candidate genes for fertility in cattle, ATP2B1, SOX5, WDR27, ARHGAP12, CACNA1D, ANKRD6, GRIA3, ZNF521 and CAST822 have maximum high confidence variants mapped in them. The SNPs found mapped in the candidate genes will be important genetic tools in the search for phenotype-modifying nucleotide changes and will aid in formulating relevant genetic improvement programmes for dairy cattle.

Genetic characterization and population structure of different coat colour variants of Badri cattle.

The present study aimed to genetically characterize the Badri cattle and its three colour variants and assess their population structure using 24 microsatellite markers. Out of 96 animals analyzed, 32 each were collected from grey (GVBC), brown (BrVBC) and black (BVBC) colour variants of Badri cattle (BC). The genetic diversity parameters including allele frequencies, observed and effective number of alleles, observed and expected heterozygosity, PIC, Shannon's indices and F-statistics were estimated using POPGENE software. Bottleneck analysis was performed using both qualitative and quantitative approaches. A total of 274 alleles (50 private and 224 shared) were scored for BC, GVBC, BrVBC and BVBC with mean number of 11.417, 9.083, 9.125 and 9.083 alleles, respectively. All populations exhibited average heterozygosity estimate > 0.5 indicating existence of substantial genetic variability, concurrent with revelations from Shannon's indices. Observed mean PIC estimates (> 0.74) were indicative of optimum informativeness of used microsatellite markers. The mean inbreeding estimates (F) in GVBC, BrVBC and BVBC were 0.041, - 0.024 and 0.016, respectively. The pair wise genetic (> 0.91) pointed towards similarity between different colour variant populations. STRUCTURE analysis also revealed clear admixture for the three Badri colour variants indicating absence of genetic differentiation. The present study revealed first-hand information that populations of Badri cattle with different phenotypes with respect to coat colour are genetically related and can be considered as a single breed. The comprehensive knowledge generated for Badri cattle will help in designing breeding plan for its genetic improvement and deciding the conservation priorities.