Jadavpur University

About: Jadavpur University is a education organization based out in Kolkata, India. It is known for research contribution in the topics: Population & Fuzzy logic. The organization has 10856 authors who have published 27678 publications receiving 422069 citations. The organization is also known as: JU & Jadabpur University.

Virulence Characteristics and Molecular Epidemiology of Enteroaggregative Escherichia coli Isolates from Hospitalized Diarrheal Patients in Kolkata, India

Abstract: Enteroaggregative Escherichia coli (EAEC) is an important diarrheal enteropathogen defined by aggregative adherence to cultured epithelial cells. We have detected EAEC from 121 (6.6%) of 1,826 hospitalized patients admitted with diarrhea to the Infectious Diseases Hospital in Kolkata, India. Watery diarrhea was recorded significantly (P = 0.0142) more often in children. The majority of the EAEC isolates were not serotypeable (62%) and showed resistance to five or more antibiotics (76%). We studied different virulence genes and the molecular epidemiology of 121 EAEC isolates recovered from diarrheal patients. A PCR assay for detection of virulence genes, an assay for determination of clump formation in liquid culture, and a HeLa cell adherence assay were carried out to characterize the EAEC isolates. Investigations were also conducted to correlate the virulence gene profiles with diarrheal symptoms and molecular epidemiology by pulsed-field gel electrophoresis (PFGE). Two or more virulence genes were detected in 109 (90.1%) EAEC isolates. In the cluster analysis, some isolates with specific gene profiles and phenotypes formed a group or subcluster. This study highlights the comparative distributions of three fimbrial adhesins and other virulence genes among EAEC isolates. The diverse virulence gene and PFGE profiles, along with the existence of diverse serotypes and antibiograms, suggests that the EAEC isolates are genetically heterogeneous in Kolkata.

Petrology of Granulites from Anakapalle—Evidence for Proterozoic Decompression in the Eastern Ghats, India

Abstract: The granulite complex at Anakapalle, which was metamorphosed at ~1000 Ma, comprises orthopyroxene granulites, leptynite, khondalite, mafic granulites, calc-silicate rock, spinel granulites, and two types of sapphirine granulites-one quartz-bearing and migmatitic and the other devoid of quartz and massive. Reaction textures in conjunction with mineral-chemical data suggest several continuous and discontinuous equilibria in these rocks. In orthopyroxene granulites, dehydration-melting of biotite in the presence of quartz occurred according to the reaction biotite+quartz= garnet (Py 37 )+K-feldspar+orthopyroxene + liquid. Later, this garnet broke down by the reaction garnet (Py 37 )+quartz = orthopyroxene + plagioclase. Subsequently, coronal garnet (Py 30 ) and quartz were produced by the same reaction but proceeding in the opposite direction. In spinel granulites, garnet (Py 42 ) and sillimanite were produced by the breakdown of spinel in the presence of quartz. In the two types of sapphirine granulites, garnet with variable pyrope content broke down according to the reaction garnet = sapphirine + sillimanite + orthopyroxene. The highest pyrope content (59 mol %) was noted in garnets from quartz-free sapphirine granulites compared with the quartz-bearing one (53 mol % pyrope). The calculated positions of the mineral reactions and diserete P-T points obtained by thermobarometry define a retrograde P-T trajectory during which a steep decompression of ~1.5 kbar from P-T max of 8 kbar and 900 °C was followed by near-isobaric cooling of ~300 °C. During this decompression, garnet with variable pyrope contents in different rocks broke down on intersection with various divariant equilibria. Near-isobaric cooling resulted in the formation of coronal garnet around second-generation orthopyroxene and plagioclase replacing earlier porphyroblastic garnet in orthopyroxene granulites. It has been argued that the deduced P-T trajectory originated in an extensional regime involving either a crust of near-normal thickness of a slightly overthickened crust owing to magmatic underaccretion.