title: Pathogenicity assessment of wild-type and mouse-adapted influenza A(H1N1) pdm09 viruses in comparison with highly pathogenic influenza A(H5N1) virus.
abstract: Here we compare the results of pathological and virological examinations of mice experimentally infected with either wild-type or mouse-adapted pandemic A(H1N1) pdm09 viruses and highly pathogenic avian influenza (HPAI) virus A(H5N1). Mice were sacrificed on days 1, 3, 6, and 10 post infection or whenever morbidity was severe enough to justify euthanasia. Morbidity rates were calculated on the basis of clinical signs (weight loss, poor hair coat, hunched posture and paresis); virus-induced disease was characterised by the histopathology of lung; virus dissemination was determined by virus isolation on organ samples of lung, brain, liver, kidney and spleen. All mice infected with mouse-adapted A(H1N1) pdm09 died in the course of the experiment, whereas 20% of animals survived the infection with A(H5N1). Echinocyte formation changed the rheological properties of blood in animals infected with either mouse-adapted A(H1N1) pdm09 or A(H5N1). To sum up, the adaptation of pandemic A(H1N1) pdm09 virus can confer an enhanced virulence similar to or even exceeding that of HPAI A(H5N1) virus.
authors.affiliation: Scientific Research Institute of Experimental and Clinical Medicine, Novosibirsk, Russia. ellap@bk.ru.|Novosibirsk State University, Novosibirsk, Russia.
authors.forename: E A
authors.initials: EA
authors.lastname: Prokopyeva
authors.affiliation: State Research Center of Virology and Biotechnology "Vector", Novosibirsk, Russia.|Department of Biosciences, University of Helsinki, Helsinki, Finland.
authors.forename: A A
authors.initials: AA
authors.lastname: Romanovskaya
authors.affiliation: Scientific Research Institute of Experimental and Clinical Medicine, Novosibirsk, Russia.
authors.forename: K A
authors.initials: KA
authors.lastname: Sharshov
authors.affiliation: State Research Center of Virology and Biotechnology "Vector", Novosibirsk, Russia.
authors.forename: A V
authors.initials: AV
authors.lastname: Zaykovskaya
authors.affiliation: Scientific Research Institute of Experimental and Clinical Medicine, Novosibirsk, Russia.
authors.forename: A Yu
authors.initials: AY
authors.lastname: Alekseev
authors.affiliation: Scientific Research Institute of Experimental and Clinical Medicine, Novosibirsk, Russia.
authors.forename: A M
authors.initials: AM
authors.lastname: Shestopalov
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D053118:Influenza A Virus, H1N1 Subtype / Q000472:pathogenicity*; D053124:Influenza A Virus, H5N1 Subtype / Q000472:pathogenicity*; D008168:Lung / Q000473:pathology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009976:Orthomyxoviridae Infections / Q000473:pathology* / Q000821:virology*; D014774:Virulence; D017201:Virus Shedding