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1.
Science ; 378(6615): 56-61, 2022 10 07.
Artículo en Inglés | MEDLINE | ID: mdl-36108048

RESUMEN

Deep learning generative approaches provide an opportunity to broadly explore protein structure space beyond the sequences and structures of natural proteins. Here, we use deep network hallucination to generate a wide range of symmetric protein homo-oligomers given only a specification of the number of protomers and the protomer length. Crystal structures of seven designs are very similar to the computational models (median root mean square deviation: 0.6 angstroms), as are three cryo-electron microscopy structures of giant 10-nanometer rings with up to 1550 residues and C33 symmetry; all differ considerably from previously solved structures. Our results highlight the rich diversity of new protein structures that can be generated using deep learning and pave the way for the design of increasingly complex components for nanomachines and biomaterials.


Asunto(s)
Aprendizaje Profundo , Ingeniería de Proteínas , Materiales Biocompatibles/química , Microscopía por Crioelectrón , Modelos Moleculares , Conformación Proteica , Ingeniería de Proteínas/métodos , Subunidades de Proteína/química
2.
Science ; 378(6615): 49-56, 2022 10 07.
Artículo en Inglés | MEDLINE | ID: mdl-36108050

RESUMEN

Although deep learning has revolutionized protein structure prediction, almost all experimentally characterized de novo protein designs have been generated using physically based approaches such as Rosetta. Here, we describe a deep learning-based protein sequence design method, ProteinMPNN, that has outstanding performance in both in silico and experimental tests. On native protein backbones, ProteinMPNN has a sequence recovery of 52.4% compared with 32.9% for Rosetta. The amino acid sequence at different positions can be coupled between single or multiple chains, enabling application to a wide range of current protein design challenges. We demonstrate the broad utility and high accuracy of ProteinMPNN using x-ray crystallography, cryo-electron microscopy, and functional studies by rescuing previously failed designs, which were made using Rosetta or AlphaFold, of protein monomers, cyclic homo-oligomers, tetrahedral nanoparticles, and target-binding proteins.


Asunto(s)
Aprendizaje Profundo , Ingeniería de Proteínas , Proteínas , Secuencia de Aminoácidos , Microscopía por Crioelectrón , Cristalografía por Rayos X , Conformación Proteica , Ingeniería de Proteínas/métodos , Proteínas/química
3.
Front Immunol ; 13: 956478, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36119096

RESUMEN

Ichthyophthirius multifiliis, a ciliated parasite causing ichthyophthiriasis (white spot disease) in freshwater fishes, results in significant economic loss to the aquaculture sector. One of the important predisposing factors for ichthyophthiriasis is low water temperature (i.e., below 20°C), which affects the health and makes freshwater fishes more susceptible to parasitic infections. During ichthyophthiriasis, fishes are stressed and acute immune reactions are compromised, which enables the aquatic bacterial pathogens to simultaneously infect the host and increase the severity of disease. In the present work, we aimed to understand the parasite-bacteria co-infection mechanism in fish. Later, Curcuma longa (turmeric) essential oil was used as a promising management strategy to improve immunity and control co-infections in fish. A natural outbreak of I. multifiliis was reported (validated by 16S rRNA PCR and sequencing method) in Pangasianodon hypophthalmus from a culture facility of ICAR-CIFRI, India. The fish showed clinical signs including hemorrhage, ulcer, discoloration, and redness in the body surface. Further microbiological analysis revealed that Aeromonas hydrophila was associated (validated by 16S rRNA PCR and sequencing method) with the infection and mortality of P. hypophthalmus, confirmed by hemolysin and survival assay. This created a scenario of co-infections, where both infectious agents are active together, causing ichthyophthiriasis and motile Aeromonas septicemia (MAS) in P. hypophthalmus. Interestingly, turmeric oil supplementation induced protective immunity in P. hypophthalmus against the co-infection condition. The study showed that P. hypophthalmus fingerlings supplemented with turmeric oil, at an optimum concentration (10 ppm), exhibited significantly increased survival against co-infection. The optimum concentration induced anti-stress and antioxidative response in fingerlings, marked by a significant decrease in cortisol and elevated levels of superoxide dismutase (SOD) and catalase (CAT) in treated animals as compared with the controls. Furthermore, the study indicated that supplementation of turmeric oil increases both non-specific and specific immune response, and significantly higher values of immune genes (interleukin-1ß, transferrin, and C3), HSP70, HSP90, and IgM were observed in P. hypophthalmus treatment groups. Our findings suggest that C. longa (turmeric) oil modulates stress, antioxidant, and immunological responses, probably contributing to enhanced protection in P. hypophthalmus. Hence, the application of turmeric oil treatment in aquaculture might become a management strategy to control co-infections in fishes. However, this hypothesis needs further validation.


Asunto(s)
Bagres , Infecciones por Cilióforos , Coinfección , Enfermedades de los Peces , Hymenostomatida , Aceites Volátiles , Aeromonas hydrophila , Animales , Antioxidantes/uso terapéutico , Catalasa , Infecciones por Cilióforos/parasitología , Infecciones por Cilióforos/veterinaria , Curcuma , Brotes de Enfermedades , Proteínas Hemolisinas , Hidrocortisona/uso terapéutico , Inmunoglobulina M/uso terapéutico , Interleucina-1beta , Complejo Hierro-Dextran/uso terapéutico , Aceites Volátiles/farmacología , ARN Ribosómico 16S , Superóxido Dismutasa , Transferrinas/uso terapéutico , Agua
4.
Phys Chem Chem Phys ; 24(19): 11872-11881, 2022 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-35510632

RESUMEN

Although cubic ice (ice Ic) is considered to be an important phase of water that impacts ice cloud formation in the Earth's upper atmosphere, its properties have not been studied to the same extent as those of hexagonal ice (ice Ih). This is because pristine ice Ic is not formed in simple laboratory conditions. Ice Ic formed in ambient conditions has a stacking disordered array of both hexagonal and cubic-structured hydrogen-bonded water molecules. It is therefore an active area of research to find ways of developing stacking disorder-free pure ice Ic. We demonstrate the evolution of almost pure ice Ic structure within the spherical nanopores of a hydrostable Cr-based metal-organic framework MIL-101(Cr) with an average pore size of 1 nm by low-temperature neutron diffraction study on D2O. It is observed that at temperatures below 230 K a fraction of liquid D2O transforms into ice and more than 94% of ice crystals evolved inside the pore are cubic in shape. This is a significantly high fraction of ice Ic formed under simple conditions inside the spherical pores of a Cr-based MOF. It is also observed that upon increasing the temperature, ice Ic remains stable until its melting point, without being transformed into ice Ih. This observation is in contrast to our previous observation of ice structure in the 2D cylindrical nanopores of MCM-41, where H2O ice after creeping out from the cylindrical channel was seen to be dominated by hexagonal shape. In the present study, the D2O molecules were confined into well-defined spherical nanopores, which hindered the growth of crystals above a certain size, thus minimizing the stacking disordered array. Nanoconfinement of water inside uniform spherical pores is therefore a promising method for the evolution of a significantly large fraction of cubic ice by minimizing the stacking disorder. This finding may open up the possibility of forming ice Ic with 100% cubicity under simple laboratory conditions, which will help in exploring the microphysics of ice cloud formation in the upper atmosphere.

5.
Phys Chem Chem Phys ; 22(25): 14309-14317, 2020 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-32567617

RESUMEN

We have thoroughly investigated the crystal structure of ice evolved from super cooled water confined in MCM-41 cylindrical nano pores through a synchrotron-based X-ray diffraction (XRD) technique for two different levels of pore filling. A rigorous analysis of XRD data shows that the nucleation dynamics and the structure of nucleated ice highly depend on the level of pore filling. In the nearly fully hydrated pores, ice crystallites start nucleating inside the pores below 240 K and creep out of the pores to form bulk crystals having crystalline structure of a mixed phase of hexagonal and cubic forms. In the partially hydrated pores, on the other hand, ice crystals cannot creep out of the pore crossing the energy barrier. The crystalline ice particles remaining inside the cylindrical pore show a short range "cubic rich" structure. The "pure cubic" phase has not been identified at either of the pore fillings in these 2.5 nm average size pores. A large fraction of water inside the pores remains in the super cooled liquid phase even at 180 K. This observation is relevant for understanding the ice nucleation through the pore condensation and freezing mechanism, which is a major pathway for the formation of cirrus clouds in the upper atmosphere.

6.
J Phys Condens Matter ; 31(48): 485803, 2019 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-31422956

RESUMEN

Conventional paramagnetism-a state with finite magnetic moment per ion sans long range magnetic ordering, but with lowering temperature the moment each ion picks up a particular direction, breaking spin rotational symmetry, and results into long-range magnetic ordering. However, in systems with competing multiple degrees of freedom this conventional notion may easily break and results into short range correlation much above the global magnetic transition temperature. La2CuIrO6 with complex interplay of spins (s = 1/2) on Cu site and pseudo-spin (j  = 1/2) on Ir site owing to strong spin-orbit coupling provides fertile ground to observe such correlated phenomena. By a comprehensive temperature dependent Raman study, we have shown the presence of such a correlated paramagnetic state in La2CuIrO6 much above the long-range magnetic ordering temperature (T N ). Our observation of strong interactions of phonons, associated with Cu/Ir octahedra, with underlying magnetic degrees of freedom mirrored in the observed Fano asymmetry, which remarkably persists as high as ~3.5T N clearly signals the existence of correlated paramagnetism hence broken spin rotational symmetry. Our detailed analysis also reveals anomalous changes in the self-energy parameters of the phonon modes, i.e. mode frequencies and linewidth, below T N , providing a useful gauge for monitoring the strong coupling between phonons and magnetic degrees of freedom.

7.
J Genet ; 98(2)2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31204707

RESUMEN

In the present study, the genetic variability of the EG95 protein-coding gene in several animal and human isolates of Echinococcus granulosus was investigated. A total of 24 isolates collected from cattle, buffalo, sheep, goat, dog and man were amplified by Eg95-coding gene-specific primers. From the generated sequence information, a conceptual amino acid sequence was deduced. Phylogenetically, the Eg95 coding gene belongs to the Eg95-1/Eg95-2/Eg95-3/Eg95-4 cluster. Further confirmation on the maximum composite likelihood analysis revealed that the overall transition/transversion bias was 2.913. This finding indicated thatthere is bias towards transitional and transversional substitution. Using artificial neural networks, a B-cell epitope was predicted on primary sequence information. Stretches of amino acid residues varied between animal and human isolates when hydrophobicity was considered. Flexibility also varied between larval and adult stages of the organism. This observation is important to develop vaccines. However, cytotoxic T-lymphocyte epitopes on primary sequence data remained constant in all isolates. In this study, agretope identification started with hydrophobic amino acids. Amino acids with the same physico-chemical properties were present in the middle. The conformational propensity of the Eg95-coding gene of 156 amino acid residues had α-turns and ß-turns, and α-amphipathic regions up to 129, 138-156 and 151-155 residues, respectively. The results indicated potential T-cell antigenic sites. The overall Tajima's D value was negative (-2.404165), indicative of negative selection pressure.


Asunto(s)
Antígenos Helmínticos/genética , Antígenos Helmínticos/inmunología , Equinococosis/inmunología , Echinococcus granulosus/genética , Echinococcus granulosus/inmunología , Variación Genética , Proteínas del Helminto/genética , Proteínas del Helminto/inmunología , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Animales , Antígenos Helmínticos/química , Fenómenos Químicos , Equinococosis/parasitología , Equinococosis/prevención & control , Echinococcus granulosus/clasificación , Mapeo Epitopo , Epítopos/inmunología , Genotipo , Proteínas del Helminto/química , Antígenos de Histocompatibilidad Clase II/inmunología , Antígenos de Histocompatibilidad Clase II/metabolismo , Humanos , Filogenia , Unión Proteica , Vacunas Antiprotozoos/genética , Vacunas Antiprotozoos/inmunología
8.
J Thromb Haemost ; 14(8): 1655-67, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27241812

RESUMEN

UNLABELLED: Essentials Mechanism of thrombin-induced inflammation is not fully understood. Thrombin induced monocyte adhesion and barrier loss require Angiopoietin-2 (Ang-2). Ang-2 mediates vessel leakage and monocyte adhesion through SHP-2/p38MAPK pathway. Calcium dependent SHP2/p38MAPK activation regulates Ang-2 expression through a feedback loop. SUMMARY: Background Thrombin imparts an inflammatory phenotype to the endothelium by promoting increased monocyte adhesion and vascular permeability. However, the molecular players that govern these events are incompletely understood. Objective The aim of this study was to determine whether Angiopoietin-2 (Ang-2) has a role, if any, in regulating inflammatory signals initiated by thrombin. Methods Assessment of vascular leakage by Miles assay was performed by intra-dermal injection on the foot paw. Surface levels of intercellular adhesion molecule-1 (ICAM-1) were determined by flow cytometry. Overexpression, knockdown and phosphorylation of proteins were determined by Western blotting. Results In time-course experiments, thrombin-stimulated Ang-2 up-regulation, peaked prior to the expression of adhesion molecule ICAM-1 in human umbilical vein-derived endothelial cells (HUVECs). Knockdown of Ang-2 blocked both thrombin-induced monocyte adhesion and ICAM-1 expression. In addition, Ang-2(-/-) mice displayed defective vascular leakage when treated with thrombin. Introducing Ang-2 protein in Ang-2(-/-) mice failed to recover a wild-type phenotype. Mechanistically, Ang-2 appears to regulate the thrombin-activated calcium spike that is required for tyrosine phosphatase SHP2 and p38 MAPK activation. Further, down-regulation of SHP2 attenuated both thrombin-induced Ang-2 expression and monocyte adhesion. Down-regulation of the adaptor protein Gab1, a co-activator of SHP2, as well as overexpression of the Gab1 mutant incapable of interacting with SHP2 (YFGab1), inhibited thrombin-mediated effects, including downstream activation of p38 MAPK, which in turn was required for Ang-2 expression. Conclusions The data establish an essential role of the Gab1/SHP2/p38MAPK signaling pathway and Ang-2 in regulating thrombin-induced monocyte adhesion and vascular leakage.


Asunto(s)
Angiopoyetina 2/metabolismo , Endotelio/metabolismo , Monocitos/citología , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Animales , Calcio/química , Permeabilidad Capilar , Adhesión Celular , Citometría de Flujo , Células Endoteliales de la Vena Umbilical Humana , Humanos , Inflamación , Molécula 1 de Adhesión Intercelular/metabolismo , Sistema de Señalización de MAP Quinasas , Masculino , Ratones , Ratones Endogámicos C57BL , Mutación , Permeabilidad , Proteína Tirosina Fosfatasa no Receptora Tipo 11/metabolismo , ARN Interferente Pequeño/metabolismo , Trombina/química , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
9.
Nutr Metab Cardiovasc Dis ; 26(4): 293-301, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26868432

RESUMEN

BACKGROUND AND AIMS: Studies suggest that Gentiana lutea (GL), and its component isovitexin, may exhibit anti-atherosclerotic properties. In this study we sought to investigate the protective mechanism of GL aqueous root extract and isovitexin on endothelial inflammation, smooth muscle cell migation, and on the onset and progression of atherosclerosis in streptozotocin (STZ)-induced diabetic rats. METHODS AND RESULTS: Our results show that both GL extract and isovitexin, block leukocyte adhesion and generation of reactive oxygen species in human umbilical vein endothelial cells (HUVECs) and rat aortic smooth muscle cells (RASMCs), following TNF-alpha and platelet derived growth factor-BB (PDGF-BB) challenges respectively. Both the extract and isovitexin blocked TNF-α induced expression of ICAM-1 and VCAM-1 in HUVECs. PDGF-BB induced migration of RASMCs and phospholipase C-γ activation, were also abrogated by GL extract and isovitexin. Fura-2 based ratiometric measurements demonstrated that, both the extact, and isovitexin, inhibit PDGF-BB mediated intracellular calcium rise in RASMCs. Supplementation of regular diet with 2% GL root powder for STZ rats, reduced total cholesterol in blood. Oil Red O staining demonstrated decreased lipid accumulation in aortic wall of diabetic animals upon treatment with GL. Medial thickness and deposition of collagen in the aortic segment of diabetic rats were also reduced upon supplementation. Immunohistochemistry demonstrated reduced expression of vascular cell adhesion molecule-1 (VCAM-1), inducible nitric oxide synthase (iNOS), and vascular endothelial cadherin (VE-cadherin) in aortic segments of diabetic rats following GL treatment. CONCLUSIONS: Thus, our results support that GL root extract/powder and isovitexin exhibit anti-atherosclerotic activities.


Asunto(s)
Apigenina/farmacología , Movimiento Celular/efectos de los fármacos , Gentiana/química , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Inflamación/tratamiento farmacológico , Miocitos del Músculo Liso/efectos de los fármacos , Animales , Aorta/citología , Aorta/efectos de los fármacos , Aorta/metabolismo , Arteriosclerosis/tratamiento farmacológico , Becaplermina , Colesterol/sangre , Diabetes Mellitus Experimental/tratamiento farmacológico , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Molécula 1 de Adhesión Intercelular/genética , Molécula 1 de Adhesión Intercelular/metabolismo , Miocitos del Músculo Liso/metabolismo , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo II/metabolismo , Fosfolipasa C gamma/metabolismo , Raíces de Plantas/química , Proteínas Proto-Oncogénicas c-sis/farmacología , Ratas , Especies Reactivas de Oxígeno/metabolismo , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Factor de Necrosis Tumoral alfa/metabolismo , Molécula 1 de Adhesión Celular Vascular/genética , Molécula 1 de Adhesión Celular Vascular/metabolismo
10.
J Phys Condens Matter ; 26(1): 016002, 2014 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-24275331

RESUMEN

It is a tough task to distinguish a short-range ferromagnetically correlated cluster-glass phase from a canonical spin-glass-like phase in many magnetic oxide systems using conventional magnetometry measurements. As a case study, we investigate the magnetic ground state of La0.85Sr0.15CoO3, which is often debated based on phase separation issues. We report the results of two samples of La0.85Sr0.15CoO3 (S-1 and S-2) prepared under different conditions. Neutron depolarization, higher harmonic ac susceptibility and magnetic relaxation studies were carried out along with conventional magnetometry measurements to differentiate subtle changes at the microscopic level. There is no evidence of ferromagnetic correlation in the sample S-2 attributed to a spin-glass phase, and this is compounded by the lack of existence of a second order component of higher harmonic ac susceptibility and neutron depolarization. A magnetic relaxation experiment at different temperatures complements the spin glass characteristic in S-2. All these signal a sharp variance when we consider the cluster-glass-like phase (phase separated) in S-1, especially when prepared from an improper chemical synthesis process. This shows that the nonlinear ac susceptibility is a viable tool to detect ferromagnetic clusters such as those the neutron depolarization study can reveal.


Asunto(s)
Cobalto/química , Vidrio/química , Lantano/química , Fenómenos Magnéticos , Imanes/química , Neutrones , Óxidos/química , Estroncio/química , Modelos Químicos , Transición de Fase
11.
Res Vet Sci ; 93(2): 604-10, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22226073

RESUMEN

Thirty-one shiga toxin-producing (STEC) and 6 enteropathogenic Escherichia coli (EPEC) were isolated from 87 raw yak milk and 63 'churpi' samples. Of 18 stx(1) positive isolates (48.6%), 14 carried stx(1c) (77.7%). Subtyping of 28 stx(2) positive isolates (75.7%) revealed the presence of stx(2c) (9, 32.1%), stx(2d) (3, 10.7%), stx(2e) (1, 3.57%) and stx(2f) (3, 10.7%) variants. Furthermore, intimin (eaeA), enterohaemolysin (ehxA), autoagglutinating adhesin (saa), iha (adherence conferring protein), efa1 (EHEC factor for adherence), bundle forming pilli (bfpA) and toxB (type III secreted protein encoded on LEE Island, similar to toxin B of Clostridium difficile) genes were detected in 14, 16, 12, 4, 3, 2 and 2 isolates, respectively. Univariate and multivariate analysis depicted that both stx(1) and stx(2) or their variants were more likely to occur in isolates from Arunachal Pradesh (p<0.04) rather than Sikkim. Dendogram constructed on the basis of RAPD and ERIC PCR profile distributed the STEC and EPEC isolates in separate clusters irrespective of their sources and serotypes. The STEC and EPEC isolates exhibited resistance against erythromycin, amikacin, azithromycin, amoxicillin, ampicillin+cloxacillin, cephalothin, furazolidone, gentamicin, kanamycin, streptomycin and tetracycline. This is the first ever report on occurrence and characterization of STEC and EPEC isolated from yak milk and milk products.


Asunto(s)
Queso/microbiología , Escherichia coli Enteropatógena/aislamiento & purificación , Microbiología de Alimentos , Leche/microbiología , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Animales , Bovinos , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Femenino , Oportunidad Relativa
12.
J Helminthol ; 86(1): 26-9, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21281527

RESUMEN

The present study describes the activity of a nanomaterial on protoscoleces of Echinococcus granulosus, which exhibited morphological changes and apoptosis. Apoptotic changes were deduced on the basis of effector caspase activation and nucleosomal laddering. Invaginated protoscoleces maintained in vitro became evaginated and had hooks, presumptive suckers and stalks. Degenerative changes of protoscoleces were evidenced after treatment with praziquantel and nano-combination. Protoscoleces treated with praziquantel had distinct attestation of necrosis and nano-combination-treated protoscoleces had signatures of apoptosis.


Asunto(s)
Antihelmínticos/farmacología , Echinococcus granulosus/efectos de los fármacos , Nanoestructuras/química , Praziquantel/farmacología , Animales , Apoptosis/efectos de los fármacos , Caspasa 3/metabolismo , Echinococcus granulosus/citología , Echinococcus granulosus/enzimología , Proteínas del Helminto/metabolismo
13.
J Phys Condens Matter ; 23(42): 426005, 2011 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-21983174

RESUMEN

The effect of electron doping on the magnetic properties of the brownmillerite type bilayered compounds has been investigated by neutron powder diffraction in La substituted Ca(2.5-x)La(x)Sr(0.5)GaMn(2)O(8) compounds (x = 0.05 and 0.1), in comparison with the undoped compound (x = 0). In all compounds, a long-range three-dimensional collinear antiferromagnetic (AFM) structure is found below the Néel temperature T(N) of the respective compound, whereas, well above T(N), three-dimensional short-range magnetic ordering is observed. In the intermediate temperature range just above T(N), a strong effect of electron doping (La substitution) on the magnetic correlations has been observed. Here, a short-range AFM correlation with a possible dimensionality of three has been found for substituted compounds (x = 0.05 and 0.1) as compared to the reported two-dimensional long-range AFM ordering in the parent compound. With increasing electron doping, a decrease in T(N) is also observed. The short-range magnetic correlations set in over a large temperature range above T(N). A magnetic phase diagram in the x-T plane is proposed from these results.

14.
Asian Pac J Trop Med ; 4(8): 589-93, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21914532

RESUMEN

Gastrointestinal (GI) parasitism is the most serious constraint throughout the world in small ruminants which causes significant production loss in animals. GI parasites are major contributor to reduce productivity in terms of meat, milk and wool in animals. Control of GI parasite is done primarily by anthelmintic treatment where choice and schedule of treatment is done after identification and quantitation of individual parasite. Identification of GI parasites is done through microscopic method by identifying specific morphological characteristics of egg and larva (L(3)). Since most of parasite eggs are having similar morphological characteristics, identification up to species level through microscopy is not possible in most of cases. To address this issue, molecular techniques are the viable alternative for identification of species as well as molecular level differences within a species (isolates) of parasites. Different DNA based molecular techniques viz. PCR, AFLP, RAPD, RFLP, PCR-SSCP, real time PCR, DNA microarray etc. have been used for identification and to assess the genetic diversity among parasite population. For identification of species, the characteristic sequence of genomic DNA of different species should differ to allow the delineation of species, but at the same time, no/minor variation within the species should exist. In contrast, for purpose of identifying population variants (strains/isolates), a considerable degree of variation in the sequence should exist within a species. Various target regions, including nuclear ribosomal DNA (rDNA), mitochondrial DNA (mtDNA) or repetitive DNA elements (microsatellite loci), which show considerable variation in the number of repeats within individuals have been employed to achieve the identification of parasites species or strain.


Asunto(s)
ADN de Helmintos/análisis , ADN Ribosómico/análisis , Parasitosis Intestinales/diagnóstico , Nematodos/genética , Infecciones por Nematodos/diagnóstico , Rumiantes/parasitología , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Animales , Huevos/clasificación , Parasitosis Intestinales/parasitología , Parasitosis Intestinales/veterinaria , Larva/clasificación , Larva/genética , Nematodos/clasificación , Nematodos/aislamiento & purificación , Infecciones por Nematodos/parasitología , Infecciones por Nematodos/veterinaria , Análisis de Secuencia por Matrices de Oligonucleótidos , Polimorfismo Conformacional Retorcido-Simple , Técnica del ADN Polimorfo Amplificado Aleatorio , Reacción en Cadena en Tiempo Real de la Polimerasa , Sensibilidad y Especificidad , Especificidad de la Especie
15.
Mol Biol Rep ; 38(3): 2067-73, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20852940

RESUMEN

Echinococcus granulosus is a parasitic helminth which affects both man and animals. During infection with larval stage of the organism secretory and membrane-bound (S/M) proteins play a meaningful role for evasion of immune system. Antigen B (AgB) is one of them. Present investigation has defined sequence diversity of AgB2 subunit of cattle and buffalo isolates of the organism. A total of 55 isolates were screened by polymerase chain reaction based single stranded conformation polymorphism (PCR-SSCP). Subsequently, six conformers could be detected. Based on predicted amino acid sequences of 90 amino acid residues, three clusters could be deduced. Sequence information of two buffalo isolates was homologous to AgB4 indicating gene switching phenomenon in between closely related isoforms. Numerical value of Tajima's D test proved negative selection pressure. Using artificial neural network (ANN), B cell linear epitope and stretches of agretope were predicted. Three clusters could be defined on the basis of B cell linear epitope. Out of three clusters, two showed more than 50% binding propensity with same MHCII alleles whereas, cluster 3 exhibited binding propensity with other MHCII alleles (DRB1_1501, DRB1_1502). Relative expression of AgB2 was more in active cysts (1.636 ± 0.092) followed by degenerating (0.449 ± 0.037) and calcified (0.255 ± 0.008). This result suggested that relative expression of AgB2 declines with progression of the disease. Using recombinant AgB2 sensitivity, specificity and accuracy of the ELISA test was 96.7, 94.7 and 95.9%, respectively. No cross reactivity was found with common cestode and trematode infected cattle and buffalo because cross reactive antigen was expressed intracellularly. Finally, this was concluded that AgB2 is the suitable immunological marker for detection, diagnosis and progression of the disease.


Asunto(s)
Antígenos Helmínticos/genética , Echinococcus granulosus/genética , Echinococcus granulosus/inmunología , Estadios del Ciclo de Vida/genética , Subunidades de Proteína/genética , Animales , Antígenos Helmínticos/inmunología , Bovinos , Echinococcus granulosus/crecimiento & desarrollo , Echinococcus granulosus/aislamiento & purificación , Ensayo de Inmunoadsorción Enzimática , Genotipo , India , Filogenia , Polimorfismo Conformacional Retorcido-Simple , Subunidades de Proteína/inmunología , Proteínas Recombinantes/inmunología , Serotipificación
16.
J Helminthol ; 85(2): 204-9, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20804642

RESUMEN

This study evaluated the existence of different genotypes of Haemonchus contortus prevailing among goats in West Bengal, India. These parasites were isolated from the abomasum of goat intestine and the molecular characterization was performed by comparing variation of nucleotide sequences of the internal transcribed spacer 1 (ITS-1) gene region. Single-strand conformation polymorphism (SSCP) analysis of ITS-1 amplified product showed the presence of three distinct conformations both in male and female parasites. The sequence analysis of conformations showed two single nucleotide polymorphisms (SNP) in male parasites at nucleotide positions 106 and 107 and one SNP was detected in female parasites at nucleotide position 157. These nucleotide variations in different isolates did not alter the interior loop structure of the predicted secondary RNA, therefore we believe these variations may not be responsible for any evolutionary changes among conformations.


Asunto(s)
Cabras/parasitología , Haemonchus/clasificación , Haemonchus/genética , Animales , Análisis por Conglomerados , ADN de Helmintos/química , ADN de Helmintos/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Femenino , Genotipo , Haemonchus/aislamiento & purificación , India , Intestinos/parasitología , Masculino , Datos de Secuencia Molecular , Filogenia , Polimorfismo de Nucleótido Simple , Polimorfismo Conformacional Retorcido-Simple , Análisis de Secuencia de ADN
17.
J Helminthol ; 85(2): 196-203, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20735897

RESUMEN

Cystic echinococcosis (CE) caused by the larval stage of Echinococcus granulosus is a disease that affects both humans and animals. In humans the disease is treated by surgery with a supplementary option of chemotherapy with a benzimidazole compound. During the present study heat-shock protein 60 (HSP 60) was identified as one of the most frequently expressed biomolecules by E. granulosus after albendazole treatment. Data were correlated with 14-3-3 protein signature, and overexpression of this molecule after albendazole induction was an indicator of cell survival and signal transduction during in vitro maintenance of E. granulosus for up to 72 h. This observation was further correlated with a uniform expression pattern of a housekeeping gene (actin II). Out of three ß-tubulin gene isoforms of E. granulosus, ß-tubulin gene isoform 2 showed a conserved point mutation indicative of benzimidazole resistance.


Asunto(s)
Proteínas 14-3-3/genética , Antihelmínticos/farmacología , Chaperonina 60/genética , Resistencia a Medicamentos , Echinococcus granulosus/efectos de los fármacos , Echinococcus granulosus/genética , Proteínas 14-3-3/biosíntesis , Secuencia de Aminoácidos , Animales , Chaperonina 60/biosíntesis , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Datos de Secuencia Molecular , Proteínas Mutantes/genética , Mutación Puntual , Tubulina (Proteína)/genética
18.
Trop Anim Health Prod ; 43(3): 705-10, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21104315

RESUMEN

A total of 107 faecal samples were collected from diarrhoeic lambs of high altitude terrains (2,000 to 5,000 m above the mean sea level) of Tawang and West Kameng districts of Arunachal Pradesh, India. Total 234 Escherichia coli were isolated and further subjected to PCR for the study of virulence repertoire characteristics of Shiga toxin-producing E. coli (STEC) and enterotoxigenic E. coli (ETEC). Out of the 234 isolated E. coli, 32% were found positive for STEC, and 9% were carrying virulence gene for ETEC. The isolated STEC serogroups were O159, O127, O120, O113, O60, O30, O25, O8 and O2. Of all the 74 STEC strains, PCR showed that 18% isolates carried stx ( 1 ), 26% possessed stx ( 2 ) and 47% produced positive amplicon for both. Other virulent attributes like intimin (eaeA), enterohaemolysin (ehxA) and STEC auto-agglutinating adhesin (saa) were present in 18%, 43% and 44% of the isolates, respectively. The isolated ETEC serogroups were O172, O170, O159, O146, O127, O120, O113, O86, O75, O60, O30, O25, O8, O2, OR and OUT. Of the 22 ETEC-positive isolates, 23%, 18% and 4.5% possessed the gene only for LT, STa and STb, respectively, whereas 54% carried genes for both LT and STb. Some serogroups of E. coli like O159, O127, O120, O113, O60, O30, O25, O8 and O2 possessed genes for both Shiga toxin and enterotoxin. This study is the first report of ETEC isolation from diarrhoeic lambs in India. The moderately high proportion of STEC and ETEC in the diarrhoeic lambs implicated that these animals are important reservoir of STEC and ETEC. This is really a grave concern for the 'brokpas' and nomads (shepherds) who share a close relationship with this animals for their livelihood. This study also indicates that ETEC may be a major cause for frequent diarrhoeal episodes in lambs of this region.


Asunto(s)
Diarrea/veterinaria , Escherichia coli Enterotoxigénica/aislamiento & purificación , Infecciones por Escherichia coli/veterinaria , Enfermedades de las Ovejas/microbiología , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Animales , Portador Sano/microbiología , Portador Sano/veterinaria , ADN Bacteriano/química , ADN Bacteriano/genética , Diarrea/microbiología , Escherichia coli Enterotoxigénica/genética , Escherichia coli Enterotoxigénica/patogenicidad , Infecciones por Escherichia coli/microbiología , Heces/microbiología , India , Reacción en Cadena de la Polimerasa/veterinaria , Ovinos , Escherichia coli Shiga-Toxigénica/genética , Escherichia coli Shiga-Toxigénica/patogenicidad , Factores de Virulencia/genética , Factores de Virulencia/aislamiento & purificación
19.
Trop Anim Health Prod ; 42(7): 1481-6, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20411327

RESUMEN

Gastrointestinal parasitic infection is highly prevalent in the North Eastern States (NEH) of India and accounted for significant economic losses across various livestock species. Productivity of cattle in terms of milk yield was estimated to be considerably higher (3,715, 3,590, and 3,154 L) due to strategic anthelmintic treatment as compare to control group (2,928 L). Based on the probability of occurrence of parasitic infection as well as increase in value of milk production, the possible economic gain at state level has been estimated to be Rs. 46 million, Rs. 35 million, and Rs. 14 million, depending upon the different strategic treatment. The government may take up the program to educate the cattle farmers on strategic management against parasitic infection and simultaneously making available various anthelmintic medicines. This public responsibility of the government to minimize the risk and economic loss due to gastrointestinal parasite infection may reduce the private cost and thereby would increase the social benefits in North Eastern states of India.


Asunto(s)
Enfermedades de los Bovinos/economía , Industria Lechera/economía , Enfermedades Gastrointestinales/veterinaria , Animales , Antihelmínticos/economía , Antihelmínticos/uso terapéutico , Bovinos/parasitología , Enfermedades de los Bovinos/parasitología , Enfermedades de los Bovinos/prevención & control , Industria Lechera/métodos , Femenino , Enfermedades Gastrointestinales/economía , Enfermedades Gastrointestinales/parasitología , Enfermedades Gastrointestinales/prevención & control , India , Lactancia/fisiología , Leche/metabolismo , Factores de Riesgo , Tiempo (Meteorología)
20.
Res Vet Sci ; 89(2): 196-9, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20347460

RESUMEN

The objective of this study was to evaluate the immunotherapeutic potential of heat killed Mycobacterium phlei in broiler chicken against experimentally produced Eimeria tenella infection. The selected dose of E. tenella oocyst (5x10(3) sporulated oocysts per bird) was capable of producing a mild form of caecal coccidiosis as observed by significant difference in body weight gain, clinical findings and caecal lesion score. Heat killed M. phlei was fed orally at 10 mg per bird with sterile PBS vehicle at alternate day for four doses. Our study reveals that per day body weight gain was significantly (p<0.01) higher for healthy control compared to coccidia infected group. The group fed M. phlei along with coccidial challenge showed significantly (p<0.05) higher body weight gain than infected control group. Heat killed M. phlei feeding also found effective to reduce the caecal lesion score significantly (p<0.05) in comparison to E. tenella infected untreated group. IgA concentrations in serum and bile at 7-day post challenge of coccidial oocyst was also significantly (p<0.01) higher in M. phlei fed group when compared to coccidia infected and healthy control group. We concluded that use of heat killed M. phlei has a beneficial role as an immunostimulant against caecal coccidiosis in broiler chicken.


Asunto(s)
Enfermedades del Ciego/veterinaria , Pollos/crecimiento & desarrollo , Coccidiosis/veterinaria , Mycobacterium phlei/fisiología , Enfermedades de las Aves de Corral/prevención & control , Adyuvantes Inmunológicos , Alimentación Animal , Animales , Enfermedades del Ciego/inmunología , Enfermedades del Ciego/parasitología , Enfermedades del Ciego/prevención & control , Coccidiosis/inmunología , Coccidiosis/parasitología , Coccidiosis/prevención & control , Dieta/veterinaria , Calor , Enfermedades de las Aves de Corral/inmunología , Enfermedades de las Aves de Corral/parasitología , Aumento de Peso
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