Karakterizacija rotavirusa izdvojenih iz bivola, peradi i čovjeka u Zapadnoj Indiji.

The present investigation describes the detection of rotaviruses among buffalo, poultry and humans. A total of 83 buffalo, 54 poultry faecal and 81 human stool samples were screened by RNA-PAGE for the presence of rotavirus, of which 6 buffalo (12.5%), 4 poultry (7.84%) and 16 human (20.25%) samples were detected positive. All the buffalo and human rotavirus PAGE positive samples depicted a characteristic group A rotavirus migration pattern (4:2:3:2) of RNA segments, whereas a group D like migration pattern (5:2:2:2) was observed in poultry samples. Out of 26 rotavirus positive samples, all the buffalo (23.07%) rotavirus positive samples showed a long electropherotype, while a short migration pattern was revealed in avian samples (15.38%). Among human samples, the majority of the samples (60%) were long electropherotypes followed by short electropherotypes (40%). Hence, a total of 10 different electropherotypes were identified among the three host species, of which four belonged to buffaloes, one poultry, five human, and one human sample was of mixed infection. RNA-PAGE positive samples were further confirmed for the presence of rotavirus by VP4 & VP7 gene specific RT-PCR. The partial length amplification of the VP4 gene of buffalo and human rotaviruses yielded 856bp and 876bp products, respectively. The VP7 gene of both buffalo and human rotaviruses yielded 1062 bp products. On G genotyping of RT-PCR positive buffalo rotavirus samples, none of the samples revealed any G6, G8, and G10 type specific products. However, P genotyping of the same samples revealed the P[11] genotype in only 2 (33.33%) of the buffalo samples. Among the human rotaviruses, 6 (37.5%) were typed as G[1] genotype but remained untypeable for P genotypes. The VP4 and VP7 genes of avian rotavirus could not be amplified. However, the VP6 gene of all avian rotavirus yielded an amplicon of 493bp . The study reports probably the first ever detection of the group D avian rotavirus in Western India.Istraživani su rotavirusa u bivola, peradi i čovjeka. Ukupno su na prisutnost rotavirusa bila pretražena 83 uzorka fecesa bivola, 54 peradi i 81 uzorak stolice čovjeka probirnim RNA-PAGE testom, od čega je pozitivnih bilo šest (12,5%) uzoraka bivola, četiri (7,84%) uzorka peradi i 16 (20,25%) uzoraka stolice čovjeka. Svi bivolji i ljudski uzorci rotavirusa pozitivni poliakrilamid gel elektroforezom pokazivali su profil RNA segmenata karakterističan za skupinu A rotavirusa (4:2:3:2), dok su uzorci karakteristični za rotaviruse skupine D (5:2:2:2) bili dokazani u peradi. Svi pozitivni uzorci iz bivola (23,07%) pokazivali su dugi elekroferotip, dok je kratak elekroferotip ustanovljen u uzorcima peradi (15,38%). Većina (60%) ljudskih uzoraka rotavirusa imala je dugi elektroferotip, a preostalih 40% kratki. Ukupno je 10 različitih elektroferotipova bilo dokazano u trima pretraživanima domaćinima od čega su četiri pripadala bivolu, jedan peradi i pet čovjeku, a jedan uzorak iz čovjeka dokazan je kod mješovite infekcije. Prisutnost rotavirusa u RNA-PAGE pozitivnim uzorcima bila je dodatno potvrđena RT-PCR-om specifičnim za gene VP4 i VP7. Djelomično umnožen odsječak gena za VP4 bivoljih rotavirusa sadržavao je 856 bp, a ljudskih rotavirusa 876 bp. Proizvod gena za VP7 i bivoljih i ljudskih rotavirusa sadržavao je 1062 bp. Genotipizacijom G RT-PCR-om pozitivnih uzoraka ni u jednom uzorku nije bio dokazan proizvod specifičan za ikoji od tipova G6, G8 i G10. Genotipizacijom P istih uzoraka ustanovljen je genotip P[11] samo u dvjema (33,33%) uzorcima bivola. Šest ljudskih rotavirusa (37,5%) bilo je tipizirano kao genotip G[1], ali se nisu mogli tipizirati na osnovi genotipa P. Geni za VP4 i VP7 ptičjih rotavirusa nisu se mogli umnožiti. Međutim gen za VP6 svih ptičjih rotavirusa dao je fragment od 493 bp. Ovo je prvi dokaz skupine D rotavirusa u Zapadnoj Indiji

NTPase and 5′-RNA Triphosphatase Activities of Chikungunya Virus nsP2 Protein

Chikungunya virus (CHIKV) is an insect borne virus (genus: Alphavirus) which causes acute febrile illness in humans followed by a prolonged arthralgic disease that affects the joints of the extremities. Re-emergence of the virus in the form of outbreaks in last 6–7 years has posed a serious public health problem. CHIKV has a positive sense single stranded RNA genome of about 12,000 nt. Open reading frame 1 of the viral genome encodes a polyprotein precursor, nsP1234, which is processed further into different non structural proteins (nsP1, nsP2, nsP3 and nsP4). Sequence based analyses have shown helicase domain at the N-terminus and protease domain at C-terminus of nsP2. A detailed biochemical analysis of NTPase/RNA helicase and 5′-RNA phosphatase activities of recombinant CHIKV-nsP2T protein (containing conserved NTPase/helicase motifs in the N-terminus and partial papain like protease domain at the C-terminus) was carried out. The protein could hydrolyze all NTPs except dTTP and showed better efficiency for ATP, dATP, GTP and dGTP hydrolysis. ATP was the most preferred substrate by the enzyme. CHIKV-nsP2T also showed 5′-triphosphatase (RTPase) activity that specifically removes the γ-phosphate from the 5′ end of RNA. Both NTPase and RTPase activities of the protein were completely dependent on Mg2+ ions. RTPase activity was inhibited by ATP showing sharing of the binding motif by NTP and RNA. Both enzymatic activities were drastically reduced by mutations in the NTP binding motif (GKT) and co-factor, Mg2+ ion binding motif (DEXX) suggesting that they have a common catalytic site

Oligothiophene-derivatized azobenzene as immobilized photoswitchable conjugated systems

Immobilization of an azobenzene-bithiophene compound on a gold surface leads to self-assembled monolayers with photoswitchable electrical properties

Structural Control of the Horizontal Double Fixation of Oligothiophenes on Gold

Quaterthiophenes bearing one (1) or two (2) alkanethiol chains attached at the internal β-position of the outermost thiophene ring through a sulfide linkage have been synthesized. Cyclic voltammetric analysis of their electrochemical behavior in solution suggests that electrooxidation of the doubly substituted oligomer 2 leads to electrodeposition of a poly(disulfide) on the anode surface. Monolayers of 1 or 2 on gold surfaces have been investigated and characterized by cyclic voltammetry, ellipsometry, contact angle measurement, and X-ray photoelectron spectroscopy. The results of these investigations indicate that introduction of two thiol groups in the structure leads to double fixation of the oligothiophene chain with the main axis of the conjugated system oriented parallel to the surface. The effects of single versus double fixation of the quaterthiophene chain on the electrochemical properties and stability of the corresponding monolayers are discussed

High on-off conductance switching ratio in light-driven self-assembled molecular devices

Date du colloque : 5-9/01/2010International audienc

OPTOSAM: Surfaces aux propriétés électroniques réversiblement modifiables par stimulation optique

Date du colloque&nbsp;: 10/2008</p