• Dynamic changes in viral population structure and compartmentalization during chronic hepatitis C virus infection in children.

      Gismondi, María Inés; Díaz Carrasco, Juan María; Valva, Pamela; Becker, Pablo Daniel; Guzmán, Carlos Alberto; Campos, Rodolfo Héctor; Preciado, María Victoria; Helmholtz Centre for infection research, D-38124 Braunschweig, Germany (2013-12)
      Classic phylogenetic and modern population-based clustering methods were used to analyze hepatitis C virus (HCV) evolution in plasma and to assess viral compartmentalization within peripheral blood mononuclear cells (PBMCs) in 6 children during 3.2-9.6yr of follow-up. Population structure analysis of cloned amplicons encompassing hypervariable region 1 led to the distinction of two evolutionary patterns, one highly divergent and another one genetically homogeneous. Viral adaptability was reflected by co-evolution of viral communities switching rapidly from one to another in the context of divergence and stability associated with highly homogeneous communities which were replaced by new ones after long periods. Additionally, viral compartmentalization of HCV in PBMCs was statistically demonstrated, suggesting their role as a pool of genetic variability. Our results support the idea of a community-based structure of HCV viral populations during chronic infection and highlight a role of the PBMC compartment in the persistence of such structure.
    • Long-term effects of ocean warming on the prokaryotic community: evidence from the vibrios.

      Vezzulli, Luigi; Brettar, Ingrid; Pezzati, Elisabetta; Reid, Philip C; Colwell, Rita R; Höfle, Manfred G; Pruzzo, Carla; Department for the Study of Territory and its Resources, University of Genoa, Genoa, Italy. luigi.vezzulli@unige.it (2012-01)
      The long-term effects of ocean warming on prokaryotic communities are unknown because of lack of historical data. We overcame this gap by applying a retrospective molecular analysis to the bacterial community on formalin-fixed samples from the historical Continuous Plankton Recorder archive, which is one of the longest and most geographically extensive collections of marine biological samples in the world. We showed that during the last half century, ubiquitous marine bacteria of the Vibrio genus, including Vibrio cholerae, increased in dominance within the plankton-associated bacterial community of the North Sea, where an unprecedented increase in bathing infections related to these bacteria was recently reported. Among environmental variables, increased sea surface temperature explained 45% of the variance in Vibrio data, supporting the view that ocean warming is favouring the spread of vibrios and may be the cause of the globally increasing trend in their associated diseases.