Cloning and sequencing of the virulent gene LipL32 of Leptospira interrogans serovar Autumnalis

Aim: To clone the virulent gene LipL32 of Leptospira interrogans serovar Autumnalis and to analyze the sequence with LipL32 gene of other pathogenic serovars of Leptopsira. Materials and Methods: Leptospira interrogans serovar Autumnalis procured from Leptospira research laboratory, Chennai was used in the study. Polymerase chain reaction (PCR) was carried out for amplifying LipL32 gene using the reported primers of Leptospira Kirschnerii. The PCR product was cloned into TA cloning vector and the vector was transformed into E.Coli DH5á cells. The plasmid was isolated from E.Coli and sent for sequencing with universal primers. The sequence was submitted in genbank with accession number JQ861883. Results: The PCR product revealed an amplicon of 790 bp. The LipL32 gene sequence of Leptospira interrogans serovar Autumnalis showed 99 % similarity with most of the pathogenic Leptospires. Conclusions: LipL32 gene of Leptospira is highly conserved in most of the pathogenic Leptospires. The study concludes that this gene could be used as a target for the diagnosis of leptospirosis in animals and humans and could be tested as an important candidate antigen for vaccine production. [Vet World 2013; 6(4.000): 193-195

SARS-CoV-2 seroprevalence among the general population and healthcare workers in India, December 2020–January 2021

Background: Earlier serosurveys in India revealed seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) of 0.73% in May–June 2020 and 7.1% in August–September 2020. A third serosurvey was conducted between December 2020 and January 2021 to estimate the seroprevalence of SARS-CoV-2 infection among the general population and healthcare workers (HCWs) in India. Methods: The third serosurvey was conducted in the same 70 districts as the first and second serosurveys. For each district, at least 400 individuals aged ≥10 years from the general population and 100 HCWs from subdistrict-level health facilities were enrolled. Serum samples from the general population were tested for the presence of immunoglobulin G (IgG) antibodies against the nucleocapsid (N) and spike (S1-RBD) proteins of SARS-CoV-2, whereas serum samples from HCWs were tested for anti-S1-RBD. Weighted seroprevalence adjusted for assay characteristics was estimated. Results: Of the 28,598 serum samples from the general population, 4585 (16%) had IgG antibodies against the N protein, 6647 (23.2%) had IgG antibodies against the S1-RBD protein, and 7436 (26%) had IgG antibodies against either the N protein or the S1-RBD protein. Weighted and assay-characteristic-adjusted seroprevalence against either of the antibodies was 24.1% [95% confidence interval (CI) 23.0–25.3%]. Among 7385 HCWs, the seroprevalence of anti-S1-RBD IgG antibodies was 25.6% (95% CI 23.5–27.8%). Conclusions: Nearly one in four individuals aged ≥10 years from the general population as well as HCWs in India had been exposed to SARS-CoV-2 by December 2020