RESUMEN
Alkhumra hemorrhagic fever virus (AHFV) is an emerging novel flavivirus that was discovered in Saudi Arabia in 1995. The virus has since caused several outbreaks in the country that resulted in case fatality rates ranging from 1% to 25%. Meager information has been published on the ultrastructural features of the virus on cells under in vitro or in vivo conditions. The present electron microscopic study examined and compared the intracellular growth of the AHFV on the LLC-MK2 cells and brain cells of new born Wistar rats, inoculated intracerebrally. The cytopathological changes in both cell systems were noted, and localization of the virus particles in different cellular components was observed. Both apoptotic and lytic cell interactions were seen in the electron micrographs of both the LLC-MK2 and the rat brain cells. The results were discussed in relation to similar situations reported for other virus members of the genus Flavivirus.
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Virus de la Encefalitis Transmitidos por Garrapatas/ultraestructura , Animales , Animales Recién Nacidos , Encéfalo/citología , Encéfalo/virología , Línea Celular , Virus de la Encefalitis Transmitidos por Garrapatas/crecimiento & desarrollo , Encefalitis Transmitida por Garrapatas/patología , Encefalitis Transmitida por Garrapatas/virología , Macaca mulatta , Ratas WistarRESUMEN
The transition period is a critical time for dairy cows as the animal is subjected to the physiological stress accompanying parturition. Immunosuppression and health status were examined during this period in 80 Holstein cows. Blood samples were taken from each cow 3, 2 and 1 week before and after calving, and at calving (0 day). RNA was extracted and subjected to real-time PCR to determine mRNA levels for the immune-related genes TLR 2, 4, 6, 7 and ß-defensin 5 in addition to the reproduction-related genes prolactin and IGF-I. Results showed significant up-regulation of pro-inflammatory-selected genes, TLR 4, 6 7 and ß-defensin 5 at the third-week post-calving; however, earlier periods had lower expression of such genes. In contrast, the immunosuppression biomarker TLR2 gene was up-regulated at calving and 1 week after parturition and then down-regulated again at second and third week. Prolactin and IGF-I genes expression levels were significantly and gradually increased mainly post-partum. This research highlights that the expression patterns of TLRs, BNBD5, PRL and IGF-I could be biomarkers to follow up immune and reproductive status of dairy cow at peri-parturient period to predict the most susceptible risk time for disease incidence and to build up management protocol.
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Bovinos/fisiología , Periodo Periparto/fisiología , Transcriptoma/fisiología , Animales , Biomarcadores , Bovinos/inmunología , Bovinos/metabolismo , Femenino , Terapia de Inmunosupresión/veterinaria , Factor I del Crecimiento Similar a la Insulina/genética , Factor I del Crecimiento Similar a la Insulina/metabolismo , Periodo Periparto/inmunología , Periodo Periparto/metabolismo , Prolactina/genética , Prolactina/metabolismo , ARN Mensajero , Estrés Fisiológico/fisiología , Receptores Toll-Like/genética , Receptores Toll-Like/metabolismo , beta-Defensinas/genética , beta-Defensinas/metabolismoRESUMEN
Alkhumra hemorrhagic fever virus (AHFV) is a newly described zoonotic flavivirus that was first isolated during 1994-1995 from the Alkhumra district south of Jeddah, Saudi Arabia. Subsequently, the virus was also isolated from Makkah city (2001-2003) and Najran (2008-2009), Saudi Arabia. The virus causes acute febrile illness with hepatitis, hemorrhagic manifestations, and encephalitis. A case fatality rate of 25% was reported among hospitalized patients. Although several biological and molecular characteristics of the virus have been published, no data are available on electron microscopic features of the virus. In this article, we describe the morphological features and metrics of the AHFV particles under electron microscopy, and localization of the virus particles in brain cells of newborn Wistar rats and in Rhesus monkey (Macaca mulatta) kidney epithelial cells (LLC-MK2). Virus particles in both the LLC-MK2 cells and the rat brain cells showed dark hexagonal core (capsid) and a translucent envelope. The mean diameter of the enveloped virus particle was 40.59 ± 1.29 nm in the rat brain cells (n = 154) and 40.97 ± 1.40 nm in the LLC-MK2 cells (n = 105; p > 0.05). The virus particles, both in vitro and in vivo, were enclosed into cytoplasmic vesicles. In conclusion, the shape, size, and diameter of the AHFV particle lie within the framework of the genus Flavivirus, family Flaviviridae.
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Virus de la Encefalitis Transmitidos por Garrapatas/ultraestructura , Animales , Animales Recién Nacidos , Encéfalo/citología , Encéfalo/virología , Línea Celular , Virus de la Encefalitis Transmitidos por Garrapatas/fisiología , Macaca mulatta , Ratas , Ratas WistarRESUMEN
BACKGROUND: Alkhumra hemorrhagic fever virus (AHFV) is a flavivirus that was discovered in 1995 in Saudi Arabia. Clinical manifestations of AHFV infection include hemorrhagic fever, hepatitis, and encephalitis with a reported mortality rate as high as 25%. There are no published data on the growth characteristics of AHFV in mammalian cell lines. The objective of this study was to examine the ability of AHFV to grow and propagate in four of the commonly used mammalian cell culture lines and to determine the virus growth curve characteristics in each. MATERIALS AND METHODS: Human epidermoid carcinoma (HEp-2), LLC-MK2, Madin-Darby canine kidney (MDCK), and Vero cell lines were inoculated with AHFV. The virus production by each cell line was determined by growth curve studies. Mean titers were calculated and expressed as median tissue culture infective dose per mL (TCID50/mL). RESULTS: AHFV grew and propagated to variable titers in the employed cell lines. The highest mean titers were observed in the LLC-MK2, followed by the MDCK, Vero, and HEP-2, in descending order. CONCLUSIONS: The growth curve studies showed that AHFV can propagate in the four types of cell lines to variable titers. LLC-MK2 cells are superior to MDCK, Vero, and HEP-2 for propagation of AHFV.
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Virus de la Encefalitis Transmitidos por Garrapatas/fisiología , Cultivo de Virus/métodos , Replicación Viral/fisiología , Animales , Línea Celular , Chlorocebus aethiops , Efecto Citopatogénico Viral/fisiología , Perros , HumanosRESUMEN
We derive analytical expressions for the correlation functions of the electronic conductance fluctuations of an open quantum dot under several conditions. Both the variation of energy and that of an external parameter, such as an applied perpendicular or parallel magnetic fields, are considered in the general case of partial openness. These expressions are then used to obtain the ensemble-averaged density of maxima, a measure recently suggested to contain invaluable information concerning the correlation widths of chaotic systems. The correlation width is then calculated for the case of energy variation, and a significant deviation from the Weisskopf estimate is found in the case of two terminals. The results are extended to more than two terminals. All of our results are analytical. The use of these results in other fields, such as nuclei, where the system can only be studied through a variation of the energy, is then discussed.
RESUMEN
BACKGROUND: Alkhumra hemorrhagic fever virus (AHFV) is a newly described flavivirus first isolated in 1994-1995 from the Alkhumra district south of Jeddah, Saudi Arabia. Subsequently, the virus was also isolated from Makkah (2001-2003) and Najran (2008-2009), Saudi Arabia. METHODS: The full-length genome of an AHFV strain isolated from patients in Najran (referred to as AHFV/997/NJ/09/SA) was PCR amplified and sequenced, and compared with the sequences of 18 other AHFV strains previously isolated from Jeddah and Makkah, dengue virus (DENV), Kyasanur forest disease virus (KFDV), Langat virus, Omsk hemorrhagic fever virus (OHFV), and tick-borne encephalitis virus (TBEV). RESULTS: The RNA of the AHFV/997/NJ/09/SA strain was found to have 10,546 nucleotides encoding for a single 3,416-amino acid polyprotein, whereas the previously reported AHFV strains were composed of 10,685-10,749 nucleotides. The AHFV/997/NJ/09/SA strain showed about 99% homology with the previously reported AHFV strains. The KFDV, Langat virus, TBEV, and OHFV isolates formed a separate cluster with a variable homology. The most important variations were observed in the core protein and NS4a gene sequences of two AHFV isolates. CONCLUSION: The variation in the number of nucleotides and phylogenetic analysis with the other AHFV isolates could have resulted from recombination of circulating virus strains.
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Virus de la Encefalitis Transmitidos por Garrapatas/genética , Encefalitis Transmitida por Garrapatas/virología , Genoma Viral , ARN Viral/genética , Análisis de Secuencia de ADN , Análisis por Conglomerados , Virus de la Encefalitis Transmitidos por Garrapatas/aislamiento & purificación , Humanos , Filogenia , Poliproteínas/genética , Arabia Saudita , Homología de SecuenciaRESUMEN
This paper reports a review into the current state of tobacco use, governance and national commitment for control, and current intervention frameworks in place to reduce the use of tobacco among the populations of the Gulf Cooperation Council (GCC) member states and Yemen. It further reviews structured policy-oriented interventions (in line with the MPOWER package of 6 evidence-based tobacco control measures) that represent government actions to strengthen, implement and manage tobacco control programmes and to address the growing epidemic of tobacco use. Our findings show that tobacco control in the GCC countries has witnessed real progress over the past decades. These are still early days but they indicate steps in the right direction. Future investment in implementation and enforcement of the Framework Convention on Tobacco Control, production of robust tobacco control legislation and the establishment of universally available tobacco cessation services are essential to sustain and strengthen tobacco control in the GCC region.
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Logro , Tabaquismo/prevención & control , Regulación Gubernamental , Política de Salud , Humanos , Cooperación Internacional , Medio Oriente/epidemiología , Prevalencia , Tabaquismo/epidemiologíaRESUMEN
The physico-chemical and biological characteristics of Alkhumra hemorrhagic fever virus (AHFV) are not yet known. The present study describes the thermal stability of this virus at different temperatures for different periods. The kinetics of thermal inactivation were studied, linear regressions were plotted, the Arrhenius equation was applied, and the activation energy was calculated accordingly. Titers of the residual virus were determined in median tissue culture infective dose (TCID50), and the rate of destruction of infectivity at various temperatures was determined. Infectivity of AHFV was completely lost upon heating for 3 minutes at 60 °C and for 30 min at 56 °C. However, the virus could maintain 33.2 % of its titer after heating for 60 min at 45 °C and 32 % of its titer after heating for 60 min at 50 °C. In conclusion, AHFV is thermo-labile, and its inactivation follows first-order kinetics.
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Virus de la Encefalitis Transmitidos por Garrapatas/aislamiento & purificación , Virus de la Encefalitis Transmitidos por Garrapatas/fisiología , Calor , Inactivación de Virus , Animales , Línea Celular , Chlorocebus aethiops , Virus de la Encefalitis Transmitidos por Garrapatas/patogenicidad , HumanosRESUMEN
Alkhumra hemorrhagic fever virus (AHFV) is a novel flavivirus identified first in Saudi Arabia. In this study, successful propagation of AHFV in the brains of newborn Wistar rats is described and the median rat lethal dose (RLD50) is determined. AHFV-RNA-positive human sera diluted 1:10 were injected intracerebrally into 16, ≤24h old rats. Post-inoculation, the rats were observed daily for 30 days. Brains of moribund rats were tested for AHFV-RNA using RT-PCR and cultured in LLC-MK2 cells. The titer of the isolated virus was determined and expressed in median tissue culture infectious dose (TCID50). To determine the RLD50, AHFV brain suspension was 10-fold diluted serially and each dilution was inoculated in the cerebral hemispheres of 10 rats for a total of 90 rats. Three days post-inoculation, the rats developed tremor, irritability, convulsion, opisthotonus, and spastic paresis starting in the hind limbs and ascending to involve the whole body. All infected rats died within 3-7 days with histopathologically confirmed meningoencephalitis. AHFV-RNA was detected in the brains of all infected rats and the virus titer was 10(9.4) RLD50/ml. The virus titer in LLC-MK2 was 10(8.2) TCID50/ml. In conclusion, AHFV was propagated successfully to high titers in the brains of newborn Wistar rats.
Asunto(s)
Encéfalo/virología , Virus de la Encefalitis Transmitidos por Garrapatas/crecimiento & desarrollo , Virus de la Encefalitis Transmitidos por Garrapatas/aislamiento & purificación , Carga Viral , Animales , Animales Recién Nacidos , Virus de la Encefalitis Transmitidos por Garrapatas/patogenicidad , Encefalitis por Arbovirus/patología , Encefalitis por Arbovirus/virología , Femenino , Humanos , Dosificación Letal Mediana , Ratas , Ratas Wistar , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Cultivo de Virus/métodosRESUMEN
Alkhumra hemorrhagic fever virus (AHFV) is an emerging flavivirus that was isolated originally from Saudi Arabia in 1994-1995. The main tests used for the detection of AHFV are the real time (rt) RT-PCR and virus isolation in cell culture. In the present study the detection of AHFV by rtRT-PCR was compared with virus isolation in BHK-21, HEp-2, and LLC-MK2 cell lines. AHFV suspensions grown in BHK-21, HEp-2, and LLC-MK2 cell lines were serially diluted 10-fold from 10(-1) to 10(-11) . Samples from each dilution were used to inoculate four cell culture tubes and were also examined by the rtRT-PCR for AHFV RNA. Fifteen non-inoculated cell culture samples (five from each cell line) were included blindly in both tests. Thus, a total of 132 AHFV-positive and 15 negative control samples were tested. The rtRT-PCR could detect the viral RNA in all diluted specimens up to and including the 10(-10) dilution (40 specimens for each cell line), whereas, cell cultures were positive in 70% of specimens for BHK-21, 65% for LLC-MK2, and 45% for HEp-2 at this dilution. None of the three cell cultures nor the rtRT-PCR was positive at 10(-11) dilution. The specificity and positive predictive values of virus isolation compared to rtRT-PCR were each 100%, whereas the negative predictive values were 29.4% for BHK-21, 26.3% for LLC-MK2, and 18.5% for HEp-2. In conclusion, the rtRT-PCR is more sensitive than virus isolation for detecting AHFV.
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Técnicas de Laboratorio Clínico/métodos , Virus de la Encefalitis Transmitidos por Garrapatas/aislamiento & purificación , Encefalitis Transmitida por Garrapatas/diagnóstico , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Animales , Línea Celular , Virus de la Encefalitis Transmitidos por Garrapatas/genética , Virus de la Encefalitis Transmitidos por Garrapatas/crecimiento & desarrollo , Humanos , Valor Predictivo de las Pruebas , Arabia Saudita , Sensibilidad y Especificidad , Cultivo de Virus/métodosRESUMEN
In the title mol-ecule, C22H12N6, the fused tetracyclic core shows a small lengthwise twist as indicated by the dihedral of 2.7â (2)° between the outer rings. In the crystal, mol-ecules stack along the b-axis direction via offset π-stacking [centroid-centroid distances = 3.5282â (13) and 3.5597â (14)â Å] with the stacks weakly associated through C-Hâ¯N hydrogen bonds. The phenyl ring is rotationally disordered over two orientations with an occupancy ratio of 0.516â (4):0.484â (4).
RESUMEN
The title compound, C21H17N7O4, is in an 'extended' conformation aided by an intra-molecular N-Hâ¯O hydrogen bond. The pyrazole ring makes dihedral angles of 29.17â (6), 65.47â (4) and 9.91â (7)°, respectively, with the phenyl, pyrrole and benzene rings. In the crystal, mol-ecules are connected by pairs of N-Hâ¯O and C-Hâ¯O hydrogen bonds, forming inversion dimers which associate into ribbons running along the b axis through complementary C-Hâ¯O inter-actions.
RESUMEN
This paper reports a review into the current state of tobacco use, governance and national commitment for control, and current intervention frameworks in place to reduce the use of tobacco among the populations of the Gulf Cooperation Council [GCC] member states and Yemen. It further reviews structured policy-oriented interventions [in line with the MPOWER package of 6 evidence-based tobacco control measures] that represent government actions to strengthen,implement and manage tobacco control programmes and to address the growing epidemic of tobacco use. Our findings show that tobacco control in the GCC countries has witnessed real progress over the past decades. These are still early days but they indicate steps in the right direction. Future investment in implementation and enforcement of the Framework Convention on Tobacco Control, production of robust tobacco control legislation and the establishment of universally available tobacco cessation services are essential to sustain and strengthen tobacco control in the GCC region
Le présent article expose un état des lieux de la consommation de tabac, de la gouvernance, de l'engagement national dans la lutte antitabac, et les cadres d'intervention actuellement en place destinés à réduire la consommation de tabac dans les populations des Etats membres du Conseil de Coopération du Golfe et du Yémen. II examine également les interventions structurées pour l'élaboration de politiques [conformément au programme MPOWER qui est compose de six mesures de lutte antitabac fondées sur des données probantes] qui représentent des actions gouvernementales destinées à renforcer, mettre en oeuvre et gérer des programmes de lutte antitabac et à s'attaquer à l'épidémie croissante de tabagisme. Nos résultats révèlent que la lutte antitabac dans les pays membres du Conseil de Coopération du Golfe a réalisé des progrès tangibles au cours des dernières décennies. Toutefois, il ne s'agit que d'un début montrant la voie à suivre. De nouveaux investissements dans la mise en oeuvre et l'application de la Convention-cadre pour la lutte antitabac, la proposition d'une législation antitabac solide et l'offre de services de sevrage tabagique d'accès universel sont essentiels pour appuyer et renforcer la lutte antitabac dans la région du Conseil de Coopération du Golfe
Asunto(s)
Nicotiana , Cese del Uso de TabacoRESUMEN
BACKGROUND: Although Alkhumra haemorrhagic fever virus (AHFV) has been isolated from ticks, epidemiological data suggest that it is transmitted from livestock to humans by direct contact with animals or by mosquito bites, but not by ticks. This study was carried out to assess the ability of the virus to replicate in tick cells in vitro. METHODS: AHFV was inoculated into cell lines derived from the hard ticks Hyalomma anatolicum (HAE/CTVM9) and Rhipicephalus appendiculatus (RAE/CTVM1) and the soft tick Ornithodoros moubata (OME/CTVM24). Inoculated cells were directly examined every week for 4 weeks by real-time reverse transcription PCR and by IFAT using polyclonal antibodies. RESULTS: AHFV RNA was detected in all three inoculated tick cell lines throughout the 4-week observation period at levels up to almost twice that of the inoculum, but none of them exhibited a cytopathic effect. AHFV antigen could be detected in all three cell lines by IFAT. Titration of tick cell culture suspension in LLC-MK2 cells yielded AHFV titres of 10(6.6) 50% tissue culture infective dose (TCID50)/ml for OME/CTVM24 and 10(5.5) TCID50/ml for RAE/CTVM1 cells after 4 weeks of culturing; no viable virus was detected in HAE/CTVM9 cells. CONCLUSION: This is the first description of propagation of AHFV in tick cells.
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Virus de la Fiebre Hemorrágica de Crimea-Congo/crecimiento & desarrollo , Garrapatas/virología , Animales , Línea Celular , Células Cultivadas , Susceptibilidad a Enfermedades , Técnica del Anticuerpo Fluorescente Indirecta , Fiebre Hemorrágica de Crimea/epidemiología , Humanos , Reacción en Cadena en Tiempo Real de la Polimerasa , Garrapatas/citología , Replicación ViralRESUMEN
We propose an extension of the continuum discretized coupled channels (CDCC) method, where the projectile is described by a microscopic cluster model. This microscopic generalization (MCDCC) relies only on nucleon-target interactions, and therefore presents an important predictive power. Core excitations can be included without any further parameter. As an example, we investigate the 7Li+208Pb elastic scattering at Elab=27 and 35 MeV. The 7Li nucleus is known to present an α+t cluster structure, and is well described by the resonating group method. An excellent agreement is obtained for the 7Li+208Pb elastic cross sections, provided that breakup channels are properly included. We also present an application to inelastic scattering and discuss future applications of the MCDCC.
RESUMEN
We investigate the correlation functions of mesoscopic electronic transport in open chaotic quantum dots with finite tunnel barriers in the crossover between Wigner-Dyson ensembles. Using an analytical stub formalism, we show the emergence of a depletion and amplification of conductance fluctuations as a function of tunnel barriers for both parametric variations of electron energy and magnetoconductance fields. Furthermore, even for pure Dyson ensembles, correlation functions of conductance fluctuations in chaotic quantum dots can exhibit anticorrelation. Experimental support to our findings is pointed out.
RESUMEN
BACKGROUND: Investigations were conducted by the authors to explore an outbreak of viral hemorrhagic fever (VHF) reported in 2010 from Al-Mukalla city, the capital of Hadramout in Yemen. METHODS: From 15-17 June 2010, the outbreak investigation period, specimens were obtained within 7 days after onset of illness of 18 acutely ill patients hospitalized with VHF and 15 household asymptomatic contacts of 6 acute cases. Additionally, 189 stored sera taken from acutely ill patients with suspected VHF hospitalized in the preceding 12 months were obtained from the Ministry of Health of Yemen. Thus, a total of 222 human specimens were collected; 207 specimens from acute cases and 15 specimens from contacts. All samples were tested with RT-PCR for dengue (DENV), Alkhumra (ALKV), Rift Valley Fever (RVFV), Yellow Fever (YFV), and Chikungunya (CHIKV) viruses. Samples were also tested for DENV IgM, IgG, and NS1-antigen. Medical records of patients were reviewed and demographic, clinical, and laboratory data was collected. RESULTS: Of 207 patients tested, 181 (87.4%) patients were confirmed to have acute dengue with positive dengue NS1-antigen (97 patients, 46.9%) and/or IgM (163 patients, 78.7%). Of the 181 patients with confirmed dengue, 100 (55.2%) patients were IgG-positive. DENV RNA was detected in 2 (1%) patients with acute symptoms; both samples were molecularly typed as DENV type 3. No other VHF viruses were detected. For the 15 contacts tested, RT-PCR tests for the five viruses were negative, one contact was dengue IgM positive, and another one was dengue IgG positive. Of the 181 confirmed dengue patients, 120 (66.3%) patients were males and the median age was 24 years. The most common manifestations included fever (100%), headache (94.5%), backache (93.4%), malaise (88.4%), arthralgia (85.1%), myalgia (82.3%), bone pain (77.9%), and leukopenia (76.2%). Two (1.1%) patients died. CONCLUSIONS: DENV-3 was confirmed to be the cause of an outbreak of VHF in Al-Mukalla. It is important to use both IgM and NS1-antigen tests to confirm acute dengue particularly under the adverse field conditions, where proper storage and transportation of specimens are missing, which substantially reduce the sensitivity of the RT-PCR for detecting DENV RNA.
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Virus del Dengue/aislamiento & purificación , Brotes de Enfermedades , Dengue Grave/epidemiología , Dengue Grave/virología , Adolescente , Adulto , Anciano , Animales , Anticuerpos Antivirales/sangre , Niño , Preescolar , Estudios de Cohortes , Virus del Dengue/genética , Femenino , Enfermedades de las Cabras/epidemiología , Enfermedades de las Cabras/virología , Cabras , Humanos , Masculino , Persona de Mediana Edad , ARN Viral/análisis , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Dengue Grave/diagnóstico , Ovinos , Enfermedades de las Ovejas/epidemiología , Enfermedades de las Ovejas/virología , Yemen/epidemiología , Zoonosis/epidemiología , Zoonosis/virologíaRESUMEN
Alkhumra hemorrhagic fever virus (AHFV) is an emerging flavivirus that was discovered in 1994-1995 in Saudi Arabia. Clinical manifestations of AHFV infection include hemorrhagic fever, hepatitis, and encephalitis, with a reported mortality rate as high as 25 %. Biological characteristics of this virus have not been well defined. Agglutination of erythrocytes (hemagglutination) is a laboratory tool for studying the attachment of viruses to cellular receptors. The envelope protein contains sites for attachment to host receptors to initiate the process of infection and is thus an essential component of the virion. In the present study, we examined the ability of AHFV to agglutinate erythrocytes of 13 mammalian and avian species (human group O+, camel, cow, sheep, goat, rabbit, guinea pig, mouse, rat, chicken, duck, goose and turkey) with and without trypsin-treatment. Without trypsin treatment, AHFV failed to agglutinate erythrocytes of all examined species. Following trypsin treatment, AHFV agglutinated erythrocytes of five species, namely, goose, human group O+, rat, guinea pig, and mouse, in descending order of sensitivity. This trypsin-dependent hemagglutination test has potential for use in serological and functional studies of AHFV.
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Eritrocitos/virología , Infecciones por Flavivirus/virología , Flavivirus/fisiología , Tripsina/metabolismo , Animales , Aves , Bovinos , Pollos , Eritrocitos/inmunología , Flavivirus/inmunología , Gansos , Cobayas , Pruebas de Hemaglutinación , Humanos , Ratones , Conejos , Ratas , Ovinos , Acoplamiento ViralRESUMEN
RT-PCR to detect Alkhumra virus (ALKV) RNA in plasma or serum has been the standard practice to confirm this infection in the first seven days of illness. In this study, RT-PCR detection of viral RNA from the plasma, serum, and buffy coat (BC) was compared to virus isolation. Plasma, serum, and BC were obtained from seven patients with clinically suspected ALKV infection in Najran, Saudi Arabia. Baby hamster kidney (BHK-21) and rhesus monkey kidney (LLC-MK2) cell culture monolayers were used for virus isolation. Real-time RT-PCR was used to confirm ALKV infection and to detect viral RNA directly from plasma, serum, and BC. ALKV was isolated from five of the seven patients. The virus was isolated from all three specimen types (plasma, serum, and BC) of the five confirmed patients. ALKV RNA was detected directly by RT-PCR in BC in all five (100%) culture-positive patients and in plasma or serum in only four (80%) of the five patients. Three of the five patients for whom ALKV RNA was detected in BC also had detectable viral RNA in plasma and serum. In the remaining two patients with detectable ALKV RNA in the BC, the plasma was positive but the serum was negative in one patient, whereas the serum was positive and the plasma was negative in the other patient. The use of real-time RT-PCR to detect ALKV RNA in the BC was superior to using plasma and serum and equivalent to virus isolation.