Comparative study on the in vitro replication and genomic variability of Argentinean field isolates of bovine herpesvirus type 4 (BoHV-4).

Bovine herpesvirus 4 (BoHV-4) is a gammaherpesvirus, belonging to the Rhadinovirus genus, which is increasingly associated with various problems of the reproductive tract of cattle. In Argentina, analysis of BoHV-4 strains isolated from cervico-vaginal mucus of aborted cows revealed a high genetic divergence among strains, which could be classified in three different groups: Genotype 1 comprises Movar-like strains (European prototype), Genotype 2 includes DN599-like strains (American prototype) and Genotype 3 corresponds to a novel genotype group. Understanding the replication behavior in cell cultures and the molecular characteristics of this pathogen of cattle is critical for the rational design of in vitro experiments. The aim of this work was to quantitatively evaluate the replication properties of different Argentinean BoHV-4 strains and to characterize their phylogenetic relationships. Significant differences were evident among the virus titers of the different BoHV-4 isolates in vitro. The most conserved gene was the major capsid protein (ORF25). The glycoprotein B (gB), glycoprotein H (gH), and thymidine kinsase (TK) genes displayed both synonymous and non-synonymous substitutions, with the highest diversity observed for gB, which displayed amino acid substitutions in 24 out of the 178 positions examined. Strains 09/759, 12/512, and 07/568 presented a deletion encompassing amino acid position 27 to 35, whereas strains 07/435 and 09/227 had a deletion from position 28 to 35. Two strains, 07/435 and 09/227, also displayed the highest divergence compared to the other strains analyzed. This study provides information about the in vitro replication and behavior of nine field isolates of BoHV-4. These findings are relevant since available information on the in vitro growth characteristics of BoHV-4 strains is scarce. The results from this study may also be useful for establishing comparisons with other related viruses.

Genetic data generated from virus-host complexes obtained by membrane co-immobilization are equivalent to data obtained from tangential filtrate virus concentrates and virus cultures.

The sieving and immobilization of virus-host complexes using impact filtration (aka membrane co-immobilization or MCI) is a novel approach to the study of plankton viruses. One of the most interesting characteristics of the method is the possibility of generating data on potential viral hosts without the need of culturing hosts cells. MCI has demonstrated to be useful for studying viruses of picoalgae, but studies comparing data generated by MCI to data obtained by other techniques are lacking. In this work, Ostreococcus virus (OV) and Ostreococcus sp. sequences generated from virus-host complexes obtained by MCI were compared to sequences obtained from tangential filtration (TF) concentrates and virus cultures (VC). Statistical parsimony, phylogenetic analyses, pairwise distance comparisons, and analysis of molecular variance showed that the viral and host sequences obtained by the three methods were highly related to each other, indicating that MCI, TF, and VC produce equivalent results. Minor differences were observed among viral sequences obtained from VC and TF concentrates as well as among host sequences generated from VC and MCI. As discussed in the body of the paper, the divergence observed for cultured cells could be due to selective pressures exerted by culture conditions, whereas the correlate observed for the corresponding viral sequences could obey to a hitchhiking effect.

Small variations in the length of the cytoplasmic domain of the simian immunodeficiency virus transmembrane protein drastically affect envelope incorporation and virus entry.

Simian immunodeficiency viruses (SIVs) have an envelope (Env) glycoprotein with an unusually long cytoplasmic domain of 164 amino acids. In this article, we have characterized a series of SIV Env truncation mutants in which the cytoplasmic domain was progressively shortened from its carboxyl terminus by 20 amino acids. Expression by means of the vaccinia virus system showed that all of the SIV Env mutants were expressed and processed into the surface and transmembrane (TM) subunits. When the ability of the Env mutants to associate with SIV Gag particles was examined, we found that deletion of 20 to 80 residues from the carboxyl terminus of the SIV TM cytoplasmic tail abrogated the incorporation of the Env glycoprotein into particles. By contrast, further truncation of the SIV TM protein by 100 to 140 amino acids restored the ability of the Env protein to associate with Gag particles. Interestingly, mutants bearing a 44- or 24-amino acid cytoplasmic domain were incorporated at levels significantly higher than those of the wild-type Env. Single-cycle infectivity assays showed that Env mutants bearing cytoplasmic tails of 144 to 64 amino acids were highly inefficient at mediating virus entry. By contrast, truncation of the cytoplasmic domain to 44 or 24 amino acids drastically enhanced virus infectivity with respect to that conferred by the full-length Env protein. Our results demonstrate that small variations in the length of the SIV Env cytoplasmic domain dramatically influence Env-mediated viral functions.

Genomic analysis of bovine herpesvirus type 4 (BoHV-4) from Argentina: high genetic variability and novel phylogenetic groups.

Bovine herpesvirus 4 (BoHV-4) is a γ-herpesvirus that has been isolated both from apparently healthy animals and from cattle with a variety of clinical signs, including post-partum endometritis and abortion. BoHV-4 causes either a persistent or a latent infection in cells of the monocyte/macrophage lineage. Two groups of BoVH-4 strains have been defined based on their restriction patterns: the Movar-like strains (European prototype) and the DN 599-like strains (American prototype). The purpose of the present study was to genetically characterize wild type BoHV-4 strains isolated from vaginal discharges of aborted cows in Argentina. The virus was identified by isolation and nested PCR in all vaginal discharge samples from aborted cows, either as a sole agent or in association with other pathogens. Restriction enzyme profiling and phylogenetic analysis demonstrated that there is a high genetic variability among the studied field isolates. The existence of three groups of strains, which were designated as genotypes 1, 2 and 3, is described. Genotypes 1 and 2 possibly correspond to the Movar-like and DN 599-like groups, respectively, whereas Genotype 3 corresponds to a novel group. Two viral strains did not cluster into any of these three groups, indicating that other genotypes could be circulating in Argentina. These results suggest a complex epidemiological background for the Argentinean BoHV-4 strains, probably influenced by independent events of genetic drift. This hypothesis cannot be rejected based on the available data. However, there is no direct evidence supporting this possibility. Thus, it seems speculative to suggest that interspecific jumps are responsible for the observed phylogenetic grouping. On the other hand, our analyses suggest a geographical structure for the observed viral genotypes, since genotypes 1 and 2 included the European (Movar-like) and American (DN599-like) reference strains, respectively. Geographic dispersion is known to be a driver of herpes viruses diversification, and independent evolution in geographical isolated places ensures the emergence of particular mutations in each location due to genetic drift (Compans, 2007; Zong et al., 1999). Therefore, at this point, the genetic drift hypothesis is the one that requires less ad-hoc considerations and thus, to our understanding, is the one that fits to the findings from this study. The involvement of this genetic variability in the detection and pathogenesis of BoHV-4 remains to be investigated.

Domains in the simian immunodeficiency virus gp41 cytoplasmic tail required for envelope incorporation into particles.

The mechanism by which lentivirus envelope (Env) glycoproteins are packaged into budding virions is poorly understood. Simian immunodeficiency virus (SIV) contains an Env protein with an unusually long cytoplasmic tail. To investigate the role of this domain in the incorporation of the SIV Env into virions, we generated a series of SIV Env mutants carrying small in-frame deletions within the cytoplasmic domain. The effects of these mutations on Env synthesis, processing, and association with Gag particles were analyzed by means of the vaccinia virus expression system. All of the mutant Env glycoproteins were synthesized and processed in a manner similar to that of the wild-type Env. However, deletions affecting domains C-terminal to residue 832 in the SIV Env protein significantly impaired Env incorporation into particles. Cell surface biotinylation assays showed that this phenotype could not be attributed to inefficient cell surface expression of the Env mutants. Furthermore, when the Env deletion mutants were tested for their ability to mediate virus entry in single-cycle infectivity assays, those mutations that impaired Env incorporation also caused a severe defect in virus infectivity. Our results suggest that domains in the C-terminal third of the SIV Env protein are required for Env incorporation into particles and Env-mediated virus entry.

Opinión de los usuarios del servicio de consultas terapéuticas del Centro Andaluz de Información y Documentación de Medicamentos sobre sus publicaciones / Users opinion of the therapeutic consultation service of the Andalusian Center of Information and Documentation of publications about drugs

Objetivo: El objetivo de este estudio era conocer la opinión que los usuarios del Servicio de Consultas Terapéuticas del Centro Andaluz de Documentación e Información de Medicamentos tenían sobre las publicaciones editadas por el centro. Metodología: Se realizó un estudio descriptivo transversal entre los profesionales sanitarios que realizaron consultas al centro durante el periodo comprendido entre el 1 de junio de 2003 y el 31 de mayo de 2004. La recogida de información se realizó mediante un cuestionario telefónico expresamente diseñado para el estudio. Resultados: Se cumplimentaron un total de 127 cuestionarios, obteniéndose una tasa de contacto del 94,8% y una tasa de respuesta del 100%. La mayoría de los participantes del estudio eran farmacéuticos de hospital y médicos de Atención Primaria, con una media de edad de 43 años. Del total de encuestados, el 81,1% eran receptores de las publicaciones, de los que el 60,2y el 37,0% consideró que éstas eran de utilidad alta y muy alta, respectivamente, para su desempeño professional (AU)

Objective: This aim of the study was to know the users' opinion of the published editions carried out by the Andalusian Documentation and Drug Information Center. Methodology: A cross descriptive study among public health workers, who once asked the center for consultation from June1st, 2003 to May 31st 2004, has been carried out. The compilation of the information has been made by a designed telephone questionnaire specially designed for the study. Results: 127 questionnaires have been ful filled, with a contact rate was of 94.8% and a response rate of 100%. Most of the participants of the study were hospital pharmacists and family doctors with an average age of 43 years. An 81.1% of those polled received the published editions, of which 60.2% and 37.0% considered them to be of high and very high utility for their professional activity, respectively (AU) - and hospitalizations, suggesting the need to take preventive measures as regards to the malnutrition of these patients (AU)