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Prospecting for potential novel Bacillus thuringiensis with new holotype crystal toxins was carried out in the Western ghats hill range of Karnataka state, India. From the soil samples collected three Bt isolates SBIKWG 12, SBIKWG 24 and SBIKWG 70 were isolated. Of these while the two isolates, namely SBIKWG 12 and SBIKWG 24 produced bipyramidal crystal toxins, the third isolate produced spherical crystal. PCR screening of the isolates revealed the presence of lepidopteran and coleopteran active cry genes. Partial sequences obtained from these isolates revealed the presence of multiple crystal toxin genes. BlastX analysis of the partial gene sequences indicated the potential for the occurrence of new holotype crystal toxin genes in SBIKWG 24 and SBIKWG 70.

The decline in dengue incidence and/or prevalence during the COVID-19 pandemic (2020-22) appears to be attributed to reduced treatment-seeking rates, under-reporting, misdiagnosis, disrupted health services and reduced exposure to mosquito vectors due to prevailing lockdowns. There is limited scientific data on dengue virus (DENV) disease during the COVID-19 pandemic. Here, we conducted a community-based, cross-sectional, cluster-randomized survey to assess anti-DENV and anti-SARS-CoV-2 seroprevalence, and also estimated the spatial distribution of DENV-positive aedine mosquito vectors during the COVID-19 pandemic across all the 38 districts of Tamil Nadu, India. Using real-time PCR, the prevalence of DENV in mosquito pools during 2021 was analyzed and compared with the previous and following years of vector surveillance, and correlated with anti-DENV IgM and IgG levels in the population. Results implicate that both anti-DENV IgM and IgG seroprevalence and DENV positivity in mosquito pools were reduced across all the districts. A total of 13464 mosquito pools and 5577 human serum samples from 186 clusters were collected. Of these, 3.76% of the mosquito pools were positive for DENV. In the human sera, 4.12% were positive for anti-DENV IgM and 6.4% for anti-DENV IgG. While the anti-SARS-CoV-2 levels significantly correlated with overall DENV seropositivity, COVID-19 vaccination status significantly correlated with anti-DENV IgM levels. The study indicates a profound impact of anti-SARS-CoV-2 levels on DENV-positive mosquito pools and seropositivity. Continuous monitoring of anti-DENV antibody levels, especially with the evolving variants of SARS-CoV-2 and the surge in COVID-19 cases will shed light on the distribution, transmission and therapeutic attributes of DENV infection., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Selvavinayagam et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

In December 2023, we observed a notable shift in the COVID-19 landscape, when JN.1 omicron emerged as the predominant SARS-CoV-2 variant with a 95% incidence. We characterized the clinical profile, and genetic changes in JN.1, an emerging SARS-CoV-2 variant of interest. Whole genome sequencing was performed on SARS-CoV-2 positive clinical specimens, followed by sequence analysis. Mutations within the spike protein sequences were analysed and compared with the previously reported lineages and sub-lineages, to identify the potential impact of the unique mutations on protein structure and possible alterations in the functionality. Several unique and dynamic mutations were identified herein. Molecular docking analysis showed changes in the binding affinity, and key interacting residues of wild-type and mutated structures with key host cell receptors of SARS-CoV-2 entry viz., ACE2, CD147, CD209L and AXL. Our data provides key insights on the emergence of newer variants and highlights the necessity for robust and sustained global genomic surveillance of SARS-CoV-2., (© 2024. The Author(s).)

Early detection of latent tuberculosis infection (LTBI) is critical to TB elimination in the current WHO vision of End Tuberculosis Strategy. The study investigates whether detecting plasma cytokines could aid in diagnosing LTBI across household contacts (HHCs) positive for IGRA, HHCs negative for IGRA, and healthy controls. The plasma cytokines were measured using a commercial Bio-Plex Pro Human Cytokine 17-plex assay. Increased plasma CXCL8 and decreased MCP-1, TNF-α, and IFN-γ were associated with LTBI. Regression analysis showed that a combination of CXCL8 and MCP-1 increased the risk of LTBI among HHCs to 14-fold. Our study suggests that CXCL-8 and MCP-1 could serve as the surrogate biomarkers of LTBI, particularly in resource-limited settings. Further laboratory investigations are warranted before extrapolating CXCL8 and MCP-1 for their usefulness as surrogate biomarkers of LTBI in resource-limited settings., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Selvavinayagam et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Despite the continued vaccination efforts, there had been a surge in breakthrough infections, and the emergence of the B.1.1.529 omicron variant of SARS-CoV-2 in India. There is a paucity of information globally on the role of newer XBB variants in community transmission. Here, we investigated the mutational patterns among hospitalised patients infected with the XBB omicron sub-variant, and checked if there was any association between the rise in the number of COVID-19 cases and the observed novel mutations in Tamil Nadu, India., Methods: Nasopharyngeal and oropharyngeal swabs, collected from symptomatic and asymptomatic COVID-19 patients were subjected to real-time PCR followed by Next Generation Sequencing (NGS) to rule out the ambiguity of mutations in viruses isolated from the patients (n = 98). Using the phylogenetic association, the mutational patterns were used to corroborate clinico-demographic characteristics and disease severity among the patients., Findings: Overall, we identified 43 mutations in the S gene across 98 sequences, of which two were novel mutations (A27S and T747I) that have not been reported previously with XBB sub-variants in the available literature. Additionally, the XBB sequences from our cohort had more mutations than omicron B.1.1.529. The phylogenetic analysis comprising six major branches clearly showed convergent evolution of XBB. Our data suggests that age, and underlying conditions (e.g., diabetes, hypertension, and cardiovascular disease) or secondary complications confers increased susceptibility to infection rather than vaccination status or prior exposure. Many vaccinated individuals showed evidence of a breakthrough infection, with XBB.3 being the predominant variant identified in the study population., Interpretation: Our study indicates that the XBB variant is highly evasive from available vaccines and may be more transmissible, and potentially could emerge as the 'next' predominant variant, which likely could overwhelm the existing variants of SARS-CoV-2 omicron variants., Funding: National Health Mission (India), SIDASARC, VINNMER (Sweden), ORIP/NIH (USA)., Competing Interests: STS and SR are funded by the National Health Mission, Tamil Nadu (680/NGS/NHMTNMSC/ENGG/2021) for the Directorate of Public Health and Preventive Medicine, WGS facility. EMS is supported by the Indian Council of Medical Research (ICMR) Grant No. 45/2/2020-DDI/BMS and a Core Research Grant (CRG) of the Department of Science and Technology-Science and Engineering Research Board (DST-SERB), Government of India (File No. CRG/2019/006096). ML is supported by grants through AI52731, the Swedish Research Council, the Swedish, Physicians against AIDS Research Foundation, the Swedish International Development Cooperation Agency, SIDA SARC, VINNMER for Vinnova, Linköping University Hospital Research Fund, CALF, and the Swedish Society of Medicine. VV is supported by the Office of Research Infrastructure Programs (ORIP/NIH) base grant P51 OD011132 to ENPRC. AM is supported by a Start-up Grant No. 12020/04/2018-HR, Department of Health Research, Government of India. The authors declare that there are no other relationships or activities that might bias, or be perceived to bias, their work., (© 2023 The Author(s).)

The rapid spread of SARS-CoV-2 variants in the global population is indicative of the development of selective advantages in emerging virus strains. Here, we performed a case-control investigation of the clinical and demographic characteristics, clinical history, and virological markers to predict disease progression in hospitalized adults for COVID-19 between December 2021 and January 2022 in Chennai, India. COVID-19 diagnosis was made by a commercial TaqPath COVID-19 RT-PCR, and WGS was performed with the Ion Torrent Next Generation Sequencing System. High-quality (<5% of N) complete sequences of 73 Omicron B.1.1.529 variants were randomly selected for phylogenetic analysis. SARS-CoV-2 viral load, number of comorbidities, and severe disease presentation were independently associated with a shorter time-to-death. Strikingly, this was observed among individuals infected with Omicron BA.2 but not among those with the BA.1.1.529, BA.1.1, or the Delta B.1.617.2 variants. Phylogenetic analysis revealed severe cases predominantly clustering under the BA.2 lineage. Sequence analyses showed 30 mutation sites in BA.1.1.529 and 33 in BA.1.1. The mutations unique to BA.2 were T19I, L24S, P25del, P26del, A27S, V213G, T376A, D405N and R408S. Low SARS-CoV-2 viral load among vaccinated individuals infected with Delta B.1.617.2 and the Omicron BA.1.1.529 variant but not with Omicron BA.1.1 or BA.2 suggests that the newer strains are largely immune escape variants. The number of vaccine doses received was independently associated with increased odds of developing asymptomatic disease or recovery. We propose that the novel mutations reported herein could likely bear a significant impact on the clinical characteristics, disease progression, and epidemiological aspects of COVID-19. Surging rates of mutations and the emergence of eclectic variants of SARS-CoV-2 appear to impact disease dynamics., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Selvavinayagam, Yong, Joseph, Hemashree, Tan, Zhang, Rajeshkumar, Kumaresan, Kalpana, Kalaivani, Monika, Suvaithenamudhan, Kannan, Murugesan, Narayanasamy, Palani, Larsson, Shankar and Raju.)

Background: The magnitude of protection conferred following recovery from COVID-19 or by vaccine administration, and the duration of protective immunity developed, remains ambiguous., Methods: We investigated the factors associated with anti-SARS-CoV-2 S1 IgG decay in 519 individuals who recovered from COVID-19 illness or received COVID-19 vaccination with two commercial vaccines, viz., an adenoviral vector-based (AZD1222) and a whole-virion-based inactivated (BBV152) vaccine in Chennai, India from March to December 2021. Blood samples collected during regular follow-up post-infection/-vaccination were examined for anti-SARS-CoV-2 S1 IgG by a commercial automated chemiluminescent immunoassay (CLIA)., Results: Age and underlying comorbidities were the two variables that were independently associated with the development of a breakthrough infection. Individuals who were >60 years of age with underlying comorbid conditions (viz., hypertension, diabetes mellitus and cardiovascular disease) had a ~15 times and ~10 times greater odds for developing a breakthrough infection and hospitalization, respectively. The time elapsed since the first booster dose was associated with attrition in anti-SARS-CoV-2 IgG, where each month passed was associated with an ebb in the anti-SARS-CoV-2 IgG antibody levels by a coefficient of -6 units., Conclusions: Our findings advocate that the elderly with underlying comorbidities be administered with appropriate number of booster doses with AZD1222 and BBV152 against COVID-19., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Selvavinayagam, Yong, Tan, Zhang, Subramanian, Rajeshkumar, Vasudevan, Jayapal, Narayanasamy, Ramesh, Palani, Larsson, Shankar and Raju.)