Browsing by Author "Obolski, Uri"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- Population at risk of dengue virus transmission has increased due to coupled climate factors and population growthPublication . Nakase, Taishi; Giovanetti, Marta; Obolski, Uri; Lourenco, JoseDengue virus transmission has increased over the last four decades seemingly due to changes in climate, urbanization and population growth. Using estimates of dengue transmission suitability based on historical temperature and humidity data, we examined how shifts in these climatic variables and human population growth have contributed to the change in the geographical distribution and size of the global population living in areas with high climate suitability from 1979 to 2022. We found an expansion in climate suitability in North America, East Asia and the Mediterranean basin, where with few exceptions, endemicity is not yet established. Globally, we estimated that the population in areas with high climate suitability has grown by approximately 2.5 billion. In the Global South, this increase was largely driven by population growth in areas with historically favorable climate suitability, while in the Global North this increase predominantly occurred in previously unfavorable areas with limited population growth.
- The metabolic, virulence and antimicrobial resistance profiles of colonising Streptococcus pneumoniae shift after PCV13 introduction in urban MalawiPublication . Obolski, Uri; Swarthout, Todd D.; Kalizang’oma, Akuzike; Mwalukomo, Thandie S.; Chan, Jia Mun; Weight, Caroline M.; Brown, Comfort; Cave, Rory; Cornick, Jen; Kamng’ona, Arox Wadson; Msefula, Jacquline; Ercoli, Giuseppe; Brown, Jeremy S.; Lourenço, José; Maiden, Martin C.; French, Neil; Gupta, Sunetra; Heyderman, Robert S.Streptococcus pneumoniae causes substantial mortality among children under 5-years-old worldwide. Polysaccharide conjugate vaccines (PCVs) are highly effective at reducing vaccine serotype disease, but emergence of non-vaccine serotypes and persistent nasopharyngeal carriage threaten this success. We investigated the hypothesis that following vaccine, adapted pneumococcal genotypes emerge with the potential for vaccine escape. We genome sequenced 2804 penumococcal isolates, collected 4-8 years after introduction of PCV13 in Blantyre, Malawi. We developed a pipeline to cluster the pneumococcal population based on metabolic core genes into “Metabolic genotypes” (MTs). We show that S. pneumoniae population genetics are characterised by emergence of MTs with distinct virulence and antimicrobial resistance (AMR) profiles. Preliminary in vitro and murine experiments revealed that representative isolates from emerging MTs differed in growth, haemolytic, epithelial infection, and murine colonisation characteristics. Our results suggest that in the context of PCV13 introduction, pneumococcal population dynamics had shifted, a phenomenon that could further undermine vaccine control and promote spread of AMR.