Full-genome sequencing and phylogenetic analysis of four neurovirulent Mexican isolates of porcine rubulavirus.

We report the complete genome sequences of four neurovirulent isolates of porcine rubulavirus (PorPV) from 2015 and one historical PorPV isolate from 1984 obtained by next-generation sequencing. A phylogenetic tree constructed using the individual sequences of the complete HN genes of the 2015 isolates and other historical sequences deposited in the GenBank database revealed that several recent neurovirulent isolates of PorPV (2008-2015) cluster together in a separate clade. Phylogenetic analysis of the complete genome sequences revealed that the neurovirulent strains of PorPV that circulated in Mexico during 2015 are genetically different from the PorPV strains that circulated during the 1980s.

Peptides Derived from Glycoproteins H and B of Herpes Simplex Virus Type 1 and Herpes Simplex Virus Type 2 Are Capable of Blocking Herpetic Infection in vitro.

AIMS: The aim of this study was to design peptides derived from glycoproteins H (gH) and B (gB) of herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2) with the potential to block herpetic infection and to evaluate their ability to inhibit HSV-1 and HSV-2 infection in vitro. METHODS: A library of continuous 15-25 residue stretches (CRSs) located at the surface of gH and gB from HSV-1 and HSV-2 was created. These CRSs were analyzed, and only those that were highly flexible and rich in charged residues were selected for the design of the antiviral peptides (AVPs). The toxicity of the AVPs was evaluated by MTT reduction assays. Virucidal activity of the AVPs was determined by a plaque reduction assay, and their antiviral effect was measured by cell viability assays. RESULTS AND CONCLUSION: Four AVPs (CB-1, CB-2, U-1, and U-2) derived from gB and gH were designed and synthetized, none of which showed high levels of toxicity in Vero cells. The U-1 and U-2 gB-derived AVPs showed high virucidal and antiviral activities against both HSV-1 and HSV-2. The gH-derived peptide CB-1 showed high virucidal and antiviral activities against HSV-2, while CB-2 showed similar results against HSV-1. The peptides CB-1 and CB-2 showed higher IC50 values than the U-1 and U-2 peptides.

[Herpes simplex virus type 1: a possible sexually transmitted agent among college students]. / Virus del herpes simplex tipo 1: un posible agente de transmisión sexual en población universitaria.

OBJECTIVE: To study the factors associated with the presence of antibodies against herpes simplex virus type 1 (HSV-1) and to screen for HSV-1 in genital samples. MATERIALS AND METHODS: Students answered a survey and provided biological samples (blood and genital discharge). The detection of IgG and IgM antibodies against HSV-1 was performed by an ELISA test. From IgM positive samples we sought and extracted genital DNA and identified a beta-globulin gene and HSV-1. RESULTS: Eight hundred and fifteen students participated. IgG/HSV-1 seroprevalence was 56.7%, HSV-1 infection was associated with number of sexual partners, exchanging sex for money, same sex relationships and occasional partners. IgM/HSV-1 seroprevalence was 18.2%, 91 samples were positive for human beta-globuline but none for HSV-1 DNA. CONCLUSIONS: Epidemiological evidence suggests that HSV-1 could be transmitted by sexual contact among college students; however, HSV-1 was not detected in any of the genital samples analyzed. To further test our hypothesis we need to study HSV-1 among high risk groups or increase our sample size.

Virus del herpes simplex tipo 1: un posible agente de transmisión sexual en población universitaria / Herpes simplex virus type 1: a possible sexually transmitted agent among college students

Objetivo: Estudiar los factores asociados a la presencia de anticuerpos contra el virus del herpes simplex tipo 1 (HSV-1), así como identificar éste en muestras genitales. Métodos: Los estudiantes universitarios contestaron un cuestionario y proporcionaron muestras biológicas (sangre y exudado genital). La detección de anticuerpos clase IgG e IgM contra HSV-1 se realizó mediante ELISA. A partir de las muestras positivas a IgM se buscó su muestra genital, se extrajo ADN y se identificaron betaglobina humana así como HSV-1. Resultados: Participaron 815 estudiantes, la seroprevalencia de IgG-HSV-1 fue de 56.7 %; la infección se asoció con el número de parejas sexuales, intercambiar sexo por dinero, relaciones con personas del mismo sexo y parejas ocasionales. La seroprevalencia de IgM-HSV-1 fue de 18.2 %; a partir de estas muestras se buscó infección genital por HSV-1; 91 muestras fueron positivas a betaglobina pero en ninguna se detectó HSV-1. Conclusiones: Los datos epidemiológicos sugieren que el HSV-1 puede ser una infección de transmisión sexual en la población universitaria analizada, sin embargo, en ninguno de los individuos se corroboró presencia genital del HSV-1. Es necesario estudiar esta infección en otras poblaciones susceptibles o incrementar el tamaño de la muestra.

OBJECTIVE: To study the factors associated with the presence of antibodies against herpes simplex virus type 1 (HSV-1) and to screen for HSV-1 in genital samples. MATERIALS AND METHODS: Students answered a survey and provided biological samples (blood and genital discharge). The detection of IgG and IgM antibodies against HSV-1 was performed by an ELISA test. From IgM positive samples we sought and extracted genital DNA and identified a beta-globulin gene and HSV-1. RESULTS: Eight hundred and fifteen students participated. IgG/HSV-1 seroprevalence was 56.7%, HSV-1 infection was associated with number of sexual partners, exchanging sex for money, same sex relationships and occasional partners. IgM/HSV-1 seroprevalence was 18.2%, 91 samples were positive for human beta-globuline but none for HSV-1 DNA. CONCLUSIONS: Epidemiological evidence suggests that HSV-1 could be transmitted by sexual contact among college students; however, HSV-1 was not detected in any of the genital samples analyzed. To further test our hypothesis we need to study HSV-1 among high risk groups or increase our sample size.

Analysis of human rotavirus G1P[8] strains by RFLP reveals higher genetic drift in the VP7 than the VP4 gene during a 4-year period in Mexico.

Several studies have demonstrated that rotaviruses of the G1P[8] genotype are among the most important worldwide. Sequence analysis of G1P[8] strains has revealed high genetic variability of VP4 and VP7 genes. The aim of this study was to investigate by restriction fragment length polymorphism (RFLP) analysis the genetic variability of the VP7 and VP4 genes within rotaviruses of the G1P[8] genotype. A total of 60 rotavirus-positive fecal samples genotyped as G1P[8], were collected from children with acute diarrhea under 5 years of age, between October 1995 and October 1998. The VP7 and VP4 genes were amplified by RT/PCR, using the Beg9/End9 primer pair and the Con3 and Con2 primers, respectively. VP7 amplicons were digested with three restriction enzymes Hae III, Taq I and Rsa I in separate reactions and VP4 amplicons were digested similarly with endonucleases Hinf I, Sau96 I and Rsa I. Analysis of the digested VP7 and VP4 amplicons showed a higher genetic drift for the VP7 gene (18 RFLPs) compared to the VP4 gene (9 RFLPs). The combination of profiles for both VP7 and VP4 amplicons, showed 27 different patterns, none of them similar to the Wa-1 strain. Furthermore, RFLP analysis of these G1P[8] strains, clearly differentiated the viruses into two main clusters, both of them sharing the same restriction pattern for the VP4 gene, and a different one for the VP7 gene.

[Could influenza virus produce the first pandemic of the XXI century?]. / Podrían los virus de influenza ocasionar la primera pandemia del sialo XXI?

Since the last decade of the XX century has been increasing the frequency of outbreaks with highly pathogenic avian influenza viruses among poultry and direct transmission of these viruses to humans. These events have ignited great concern about the pandemic potential of these viruses, for that reason the study and characterization of the previously influenza viruses involved in pandemics or outbreaks has been considered of great importance. This review presents and compares the different influenza viruses involved in the XX century pandemics and outbreaks, with emphasis in the cellular receptors used by avian and human influenza viruses. And the recently finding that human respiratory tract contains both type of receptors, and finally which factors could allow a successful direct human infection with avian viruses, and how theses viruses could be transmitted among the human population.

El impacto de la biología molecular en el estudio de las infecciones virales / The impact of molecular biology in the study of viral infections

El desarrollo de las técnicas de biología molecular ha sido trascendental para el avance de la Virología en la última década. En esta revisión se presentan algunos de los avances más importantes que ha generado el estudio de dos de los virus con mayor impacto en los últimos años y en donde la aplicación de esa metodología ha sido crucial. La primera parte corresponde al VIRUS HERPES SIMPLE (HSV) cuya complejidad genética es asombrosa ya que posee como material genético un DNA de doble cadena, con 152 kilopares de bases, que presenta aproximadamente 75 marcos de lectura (ORF), que pueden codificar por lo menos para unas 72 proteínas diferentes. Estos genes se expresan durante el ciclo viral a través de un proceso altamente regulado y coordinado, como se observa en las neuronas del sistema nervioso central, a diferencia de lo que ocurre durante la latencia en neuronas sensoriales, en donde estos genes están apagados. El otro virus analizado es el VIRUS DE LA INMUNODEFICIENCIA HUMANA (HIV), el cual es un ejemplo de la enorme cantidad de información que se ha generado en menos de una década de estudio y que ha conducido no sólo a la elaboración del mapa genético viral de los genes estructurales (gag, pol y env), sino que también se han identificado por lo menos otros siete genes adicionales, cuya función es la regulación o modulación de la expresión genética viral. En relación a la patogénesis del síndrome de inmunodeficiencia adqirida (SIDA), se sabe que éste se desarrolla varios años después de la infección viral inicial; sin embargo, la replicación viral ocurre como un proceso continuo, aún en ausencia de infección clínica, lo que sugiere que la infección por HIV se inicia como un proceso caracterizado por una replicación viral persistente y una progresiva disfunción inmunológica.