Thermal Stabilization of Poliovirus Type 3 Live Vaccine Strain by Sucrose in the Presence of Magnesium Chloride

熱に極めて不安定な3型ポリオウイルス生ワクチンLeon 12a_1b株の耐熱性を庶糖と塩化マグネシウムによって増大することができた.分子量6,000のポリオエチレングリコール(PEG)はこのウイルスの耐熱性を低下し,その効果はPEGとウイルスの混合液を凍結乾燥した場合に殊に顕著であった.このウイルスは繊維性セルロースCF11に吸着され, CF11とウイルスの混合液を遠心して得られた沈澱中のウイルスの37℃での耐熱性はCF11を加えなかった対照と変らなかった. CF11とウイルスの混合液をニトロセルロース膜で濾過した場合,膜に含まれるウイルスの37℃での耐熱性は1～2週間増大しているように見えたが,濾過直後の膜からウイルスは効率良く回収されなかった.Infectivity of highly temperature-sensitive and attenuated poliovirus type 3 vaccine strain, Leon 12a_1b, at 35-37℃ was stabilized by 15-20% sucrose in the medium with 1 M MgCl_2. On the other hand, the virus stability was reduced by 10% polyethylene glycol (PEG, Mol. Wt. 6000) in the medium without MgCl_2, especially when the virus-PEG mixtures were incubated after freeze-drying. Fibrous cellulose CF11 apparently adsorbed majority of the virus and did not change its inactivation rate, when virus-cellulose mixtures were centrifuged and the precipitates were incubated at 37℃. When virus-cellulose mixtures were filtrated through nitrocellulose membranes, however, virus infectivity recovered from the cellulose on the membrane was poor for 0 day\u27s specimen, with apparent stabilization of the adsorbed virus after 1-2 weeks incubation at 37℃

Effect of Hydrochloric Acid Concentration on the Stabilization of Poliovirus at High Temperature

ポリオウィルス弱毒株Sabin 1型、LSc 2abと3型Leon 12a_1bをpH 1.3から3.0の間の種々の濃度の塩酸溶液中で50℃,15分間処理してその安定性を検討したところ,ヒトの胃酸濃度に相当するpH 2.0で最も安定であるという結果が得られた.Attenuated poliovirus Sabin strains type 1 LSc 2ab and type 3 Leon 12a_1b have been stabilized in different concentration of hydrocholoric acid (HCl) between pH 1.3 to 3.0 at 50℃ for 15 minutes. These strains were temperature stable at pH 2.0 which corresponds to the concentration of HCl in human stomach

Effect of Sucrose on the Infectivity, Migration and Neutralization of Neurovirulent Poliovirus Type 1

Infectivity of neurovirulent poliovirus type 1, Brunhilde strain, was elevated more than 1 log on human rhabdomyosarcoma (RD) cells in the presence of 7.5 percent sucrose, although migration of the virus through 15 percent sucrose solution was not significant. Apparent inhibition of virus neutralization by rabbit antiserun was obserbed at all serum dilutions tested (1:100-1:1600) in the presence of 11.25 percent sucrose and at 1:800 serum dilution in the presence of 5.6 and 2.8 percent sucrose

Molecular Epidemiology of Rotavirus in Central and Southeastern Europe▿

A surveillance network was implemented by the Istituto Superiore di Sanità of Rome in collaboration with laboratories of virology in Czech Republic, Slovenia, Croatia, Albania, and Bulgaria. About 1,500 rotavirus-positive stool samples were collected from children with severe gastroenteritis admitted to hospitals or outpatient wards between 2004 and 2006. The G and P genotypes were determined by reverse transcription-nested PCR. Significant differences were found in the geographical distributions of rotavirus genotypes between countries participating in the study. The prevalence of “common” G/P combinations, G1P[8], G3P[8], G4P[8], and G2P[4], ranged between 50 and 85%. The G9 genotype, which is emerging worldwide, was identified in 2 to 35% of all samples depending on the country. Unusual combinations, such as G1 or G4 associated with P[4] or G2 with P[8], which may have arisen by reassortment between human strains, were found in samples from 3 to 20% of patients. The uncommon genotypes G8P[8] and G10P[6], which may have an animal origin, were also identified. Double infections with two rotavirus strains were observed in between 1.7 and 14% of cases studied. Our findings might implicate challenges for rotavirus vaccine implementation in a wide geographic area of the Balkans and Central-Eastern Europe and underscore the importance of extensive strain surveillance for success in vaccine development