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We have discovered chlorophyll catalyzed 1,2-acyl migration reactions to achieve α-amino carbonyl compounds directly from the enaminones. In general, singlet oxygen is generated during photosynthesis in the photosystem II center. This singlet oxygen can readily react with the unsaturated double bonds present in biomolecules. This reactivity intrigued us to apply this concept towards unsaturated enaminones and others to achieve highly valuable compounds. Indeed, this photosensitizer is very cheap, commercially available, main group metal based and provided excellent efficiency for singlet oxygen mediated chemistry by achieving high turnover number (TON) > 300 with a high turnover frequency (TOF) of 50 h−1. Finally, a combination of DFT calculations and detailed mechanistic experiments provided the exact role of the photosensitizer and clear insights into the reaction. [ABSTRACT FROM AUTHOR]

Background: Salmonella enterica serovar Enteritidis, the most common cause of human gastroenteritis, employs several virulence factors including lipopolysaccharide (LPS) for infection and establishment of disease inside the host. The LPS of S. enterica serovar Enteritidis consists of lipid A, core oligosaccharide and O-antigen (OAg). The OAg consists of repeating units containing different sugars. The sugars of OAg are synthesized and assembled by a set of enzymes encoded by genes organized into clusters. Present study focuses on the effect of deletion of genes involved in biosynthesis of OAg repeating units on resistance to antimicrobial peptides and virulence in mice. Methods: In the present study, the OAg biosynthesis was impaired by deleting tyv, prt and wbaV genes involved in tyvelose biosynthesis and its transfer to OAg. The virulence phenotype of resulting mutants was evaluated by assessing resistance to antimicrobial peptides, serum complement, adhesion, invasion and in vivo colonization. Results: Deletion of the above three genes resulted in the production of OAg-negative LPS. All the OAg-negative mutants showed phenotype reported for rough strains. Interestingly, ΔwbaV mutant showed increased resistance against antimicrobial peptides and normal human serum. In addition, the ΔwbaV mutant also showed increased adhesion and invasion as compared to the other two O-Ag negative mutants Δtyv and Δprt. In vivo experiments also confirmed the increased virulent phenotype of ΔwbaV mutant as compared to Δprt mutant. Conclusion: OAg-negative mutants are known to be avirulent; however, this study demonstrates that certain OAg negative mutants e.g. ΔwbaV may also show resistance to antimicrobial peptides and cause colitis in Streptomyces pretreated mouse model. [ABSTRACT FROM AUTHOR]

Chlamydia trachomatis (CT) is the most common curable sexually transmitted non-viral infection, which can cause urethritis, prostatitis, orchitis and epididymitis among males. Toxoplasma gondii, a protozoan causes toxoplasmosis among humans. These infections may lead to decreased fertility. Hence, this study was aimed to estimate the seropositivity of CT and T. gondii infection among the male partners of infertile couples in Odisha, India. In this facility-based cross-sectional study, first void urine, seminal fluid and blood sample were collected from 153 males attending infertility clinics including 74 healthy controls. Urine and seminal fluid were tested through polymerase chain reaction (PCR), and enzyme-linked immunosorbent assay was used to detect immunoglobulin (Ig) G, IgA and IgM anti-Chlamydia and IgM anti-Toxoplasma antibodies through serum. The prevalence of CT was 1.26 per cent (95% CI: 0.03-6.85) as estimated from semen samples using PCR. We detected anti-Chlamydia antibodies IgM-four per cent [95% confidence interval (CI): 0.83-11.24]; IgA-28.16 per cent (95% CI: 18.13-40.09) and IgG-12.5 per cent (95% CI: 5.87-22.4) among participants. Anti-Toxoplasma antibodies IgM were observed in 27.63 per cent (95% CI: 17.98-39.08) of participants. None of the control samples were found positive. Overall seropositivity of CT and Toxoplasma infections is comparable, which suggests that greater attention is required for screening these infections at clinics, especially among infertile couples. [ABSTRACT FROM AUTHOR]

Background Dengue, caused by mosquito bite, is an emerging disease of international concern. Evidence regarding the prevalent dengue serotypes is scarce, but essential for its management during the outbreaks. Hence, we mapped the distribution and trends of currently prevalent dengue virus (DENV) serotypes in Odisha. Methods We conducted a facility-based retrospective study from referral samples sent for the diagnosis/confirmation of dengue in 2018. The samples were serologically tested for enzyme-linked immunosorbent assay (ELISA) IgM antibody and NS1. Only NS1-positive samples were chosen for sero-typing. A pool of 8-10 NS1-positive samples were analysed for district-wise serotypes. Ribonucleic acid extraction and nested polymerase chain reaction (PCR) was done from NS1-positive samples. The PCR products were then subjected to gel electrophoresis. Results A total of 2892 samples were screened for dengue virus across various districts of Odisha where 763 samples were found to be NS1-positive. Thirteen of 18 districts covering all topographies of Odisha predominantly had DENV2 serotype. Only few districts such as Balangir, Kalahandi and Rayagada had mixed serotypes. Conclusion Although DENV2 is predominantly prevalent, mixed serotypes too exist in Odisha. Evidence based on variations of dengue serotypes across topographies, seasons, gender and age groups may support public health efforts in preventing the disease.