Genomic characterization of the Yersinia genus

Background

New DNA sequencing technologies have enabled detailed comparative genomic analyses of entire genera of bacterial pathogens. Prior to this study, three species of the enterobacterial genus Yersinia that cause invasive human diseases (Yersinia pestis, Yersinia pseudotuberculosis, and Yersinia enterocolitica) had been sequenced. However, there were no genomic data on the Yersinia species with more limited virulence potential, frequently found in soil and water environments.

Results

We used high-throughput sequencing-by-synthesis instruments to obtain 25- to 42-fold average redundancy, whole-genome shotgun data from the type strains of eight species: Y. aldovae, Y. bercovieri, Y. frederiksenii, Y. kristensenii, Y. intermedia, Y. mollaretii, Y. rohdei, and Y. ruckeri. The deepest branching species in the genus, Y. ruckeri, causative agent of red mouth disease in fish, has the smallest genome (3.7 Mb), although it shares the same core set of approximately 2,500 genes as the other members of the species, whose genomes range in size from 4.3 to 4.8 Mb. Yersinia genomes had a similar global partition of protein functions, as measured by the distribution of Cluster of Orthologous Groups families. Genome to genome variation in islands with genes encoding functions such as ureases, hydrogeneases and B-12 cofactor metabolite reactions may reflect adaptations to colonizing specific host habitats.

Conclusions

Rapid high-quality draft sequencing was used successfully to compare pathogenic and non-pathogenic members of the Yersinia genus. This work underscores the importance of the acquisition of horizontally transferred genes in the evolution of Y. pestis and points to virulence determinants that have been gained and lost on multiple occasions in the history of the genus.     

Electroporation as a tool to transfer the plasmid pRL489 in Oscillatoria MKU 277

To establish the gene transfer system in the cyanobacteria, we successfully introduced the shuttle plasmid pRL489 into Oscillatoria MKU 277 by electroporation with transformation frequencies of up to 102 cfu/mug of plasmid DNA. These findings suggest that Oscillatoria MKU 277 can be used as an experimental tool for genetic maneuvering.     

Burden of congenital rubella syndrome (CRS) in India based on data from cross-sectional serosurveys, 2017 and 2019–20

BackgroundIndia has set a goal to eliminate measles and rubella/Congenital Rubella Syndrome (CRS) by 2023. Towards this goal, India conducted nationwide supplementary immunization activity (SIA) with measles-rubella containing vaccine (MRCV) targeting children aged between 9 months to <15 years and established a hospital-based sentinel surveillance for CRS. Reliable data about incidence of CRS is necessary to monitor progress towards the elimination goal.MethodsWe conducted serosurveys in 2019–20 among pregnant women attending antenatal clinics of 6 hospitals, which were also sentinel sites for CRS surveillance, to estimate the prevalence of IgG antibodies against rubella. We systematically sampled 1800 women attending antenatal clinics and tested their sera for IgG antibodies against rubella. We used rubella seroprevalence data from the current survey and the survey conducted in 2017 among antenatal women from another 6 CRS surveillance sites to construct a catalytic models to estimate the incidence and burden of CRS.ResultThe seroprevalence of rubella antibodies was 82.3% (95% CI: 80.4–84.0). Rubella seropositivity did not differ by age group and educational status. Based on the constant and age-dependent force of infection models, we estimated that the annual incidence of CRS in India was 225.58 per 100,000 live births (95% CI: 217.49–232.41) and 65.47 per 100,000 live births (95% CI: 41.60–104.16) respectively. This translated to an estimated 14,520 (95% CI: 9,225–23,100) and 50,028 (95% CI: 48,234–51,543) infants with CRS every year based on age-dependent and constant force of infection models respectively.ConclusionsOur findings indicated that about one fifth of women in the reproductive age group in India were susceptible for rubella. The estimates of CRS incidence will serve as a baseline to monitor the impact of MRCV SIAs, as well progress towards the elimination goal of rubella/CRS.     

A facile synthesis, antibacterial, and antitubercular studies of some piperidin-4-one and tetrahydropyridine derivatives

The raise in clinical significance of multidrug-resistant bacterial pathogens has directed us to synthesize 2,6-diarylpiperidin-4-one and Delta(3)-tetrahydropyridin-4-ol based benzimidazole and O-arylsulfonyl derivatives. X-ray crystal structure of tetrahydropyridinol (23) confirmed a change in conformation and orientation of substituents upon amide formation. Antibacterial activities evaluated against a wide number of bacterial pathogens (both sensitive and multidrug-resistant) revealed that 19, 27 against Staphylococcus aureus, 27 against Enterococcus faecalis, and 19, 21, 23, and 27 against Enterococcus faecium are significantly good at lowest MIC(90) (16 microg/mL). Inhibitory power noticed by 23 against Vancomycin-Linezolid-resistant E. faecalis and 27 against Vancomycin-resistant E. faecium are onefold better than the standard Linezolid and Trovafloxacin drugs, respectively. Moreover, antitubercular activity for the selected compounds against Mycobacterium tuberculosis H37Rv revealed that compounds 23, 24, and 27 expressed onefold improved potency compared to the standard Rifampicin drug.     

Extracellular phosphate solubilization by the cyanobacteriumAnabaena ARM310

Endogenous polyphosphate depletedAnabaena ARM310, solubilized extracellular tricalcium phosphate through increased phosphatase activity.     

Molecular intricacies of aerobic glycolysis in cancer: current insights into the classic metabolic phenotype

Aerobic glycolysis is the process of oxidation of glucose into pyruvate followed by lactate production under normoxic condition. Distinctive from its anaerobic counterpart (i.e. glycolysis that occurs under hypoxia), aerobic glycolysis is frequently witnessed in cancers, popularly known as the “Warburg effect”, and it is one of the earliest known evidences of metabolic alteration in neoplasms. Intracellularly, aerobic glycolysis circumvents mitochondrial oxidative phosphorylation (OxPhos), facilitating an increased rate of glucose hydrolysis. This in turn enables cancer cells to successfully compete with normal cells for glucose uptake in order to maintain uninterrupted growth. In addition, evading OxPhos mitigates excessive generation/accumulation of reactive oxygen species that otherwise may be deleterious to cells. Emerging data indicate that aerobic glycolysis in cancer also promotes glutaminolysis to satisfy the precursor requirements of certain biosynthetic processes (e.g. nucleic acids). Next, the metabolic intermediates of aerobic glycolysis also feed the pentose phosphate pathway (PPP) to facilitate macromolecular biosynthesis necessary for cancer cell growth and proliferation. Extracellularly, the extrusion of the end-product of aerobic glycolysis, i.e. lactate, alters the tumor microenvironment, and impacts cancer-associated cells. Collectively, accumulating data unequivocally demonstrate that aerobic glycolysis implicates myriad of molecular and functional processes to support cancer progression. This review, in the light of recent research, dissects the molecular intricacies of its regulation, and also deliberates the emerging paradigms to target aerobic glycolysis in cancer therapy.     

Montmorillonite K-10 clay-catalyzed Ferrier rearrangement of 2-C-hydroxymethyl-d-glycals, 3,4,6-tri-O-alkyl-d-glycals, and 3,4-(dihydro-2H-pyran-5-yl)methanol: a few unexpected domino transformations

Montmorillonite K-10 clay-catalyzed substitution reactions of 3,4,6-tri-O-alkyl-2-C-hydroxymethyl-d-glycals, 3,4,6-tri-O-acetyl-d-glycals, 3,4,6-tri-O-alkyl-d-glycals, and 3,4-(dihydro-2H-pyran-5-yl)methanol with a few alcohols and phenols are described. The reactions of 2-C-hydroxymethyl-d-glycals with phenols were similar to those of 2-C-acetoxymethyl-d-glycals and afforded pyrano[2,3-b]benzopyrans. This montmorillonite K-10 clay-catalyzed transformation is facile both under ambient (Method 1) and microwave conditions (Method 2). Ferrier rearrangement of 3,4-(dihydro-2H-pyran-5-yl)methanol with p-cresol, 2,6-xylenol, and ethanol led to totally unexpected transformations. Reaction of 2-C-hydroxymethyl-d-galactal with 2,6-dimethylphenol in the presence of montmorillonite K-10 led to a novel domino transformation affording 4-(5',6'-dihydro-4H-pyran-3'-ylmethyl)-2,6-dimethylphenol. In contrast, 3,4,6-tri-O-acetyl-d-glucal furnished the Ferrier rearrangement product, 2,6-dimethylphenyl 4,6-di-O-acetyl-2,3-dideoxy-α-d-erythro-hex-2-enopyranoside. Also, isomerization of 3,4,6-tri-O-alkyl-d-glycals to products of allylic rearrangement, 2,3-unsaturated-O-glycosides in good yields is reported.     

Pathology of Equine Influenza virus (H3N8) in Murine Model

Equine influenza viruses (EIV)—H3N8 continue to circulate in equine population throughout the world. They evolve by the process of antigenic drift that leads to substantial change in the antigenicity of the virus, thereby necessitating substitution of virus strain in the vaccines. This requires frequent testing of the new vaccines in the in vivo system; however, lack of an appropriate laboratory animal challenge model for testing protective efficacy of equine influenza vaccine candidates hinders the screening of new vaccines and other therapeutic approaches. In the present investigation, BALB/c mouse were explored for suitability for conducting pathogenecity studies for EIV. The BALB/c mice were inoculated intranasally @ 2×10^6.24 EID₅₀ with EIV (H3N8) belonging to Clade 2 of Florida sublineage and monitored for setting up of infection and associated parameters. All mice inoculated with EIV exhibited clinical signs viz. loss in body weights, lethargy, dyspnea, etc, between 3 and 5 days which commensurate with lesions observed in the respiratory tract including rhinitis, tracheitis, bronchitis, bronchiolitis, alveolitis and diffuse interstitial pneumonia. Transmission electron microscopy, immunohistochemistry, virus quantification through titration and qRT-PCR demonstrated active viral infection in the upper and lower respiratory tract. Serology revealed rise in serum lactate dehydrogenase levels along with sero-conversion. The pattern of disease progression, pathological lesions and virus recovery from nasal washings and lungs in the present investigations in mice were comparable to natural and experimental EIV infection in equines. The findings establish BALB/c mice as small animal model for studying EIV (H3N8) infection and will have immense potential for dissecting viral pathogenesis, vaccine efficacy studies, preliminary screening of vaccine candidates and antiviral therapeutics against EIV.     

Design and Facile Synthesis of New Dinucleotide Cap Analog Containing Both 2′ and 3′-OH Modification on M7Guanosine Moiety

The first example of the synthesis of new dinucleotide cap analog containing 2^′,3^′-diacetyl group on m⁷guanosine moiety is described. The desired modified cap analog, m^{7,2′,3′–diacetyl}G[5^′]ppp[5^′]G has been obtained by the coupling reaction of triethylamine salt of m^{7,2′,3′–diacetyl}GDP with ImGMP in presence of ZnCl₂ as a catalyst in 62% yield with high purity. The structure of new cap analog has been confirmed by ¹H and ³¹P NMR and mass data.