Radioimmunological analysis of the antigenic variability of influenza virus nucleoprotein

Influenza A virus ability to bind anti-NP monoclonal antibodies to two viral strains has been studied by radioimmunoassay on polyethylene film with the subsequent autoradiographic registration of results. Monoclonal antibodies were obtained to the viral strains differing in antigenic formula of outer glycoproteids and isolated at different time. The studied influenza viruses were divided into seven groups due to their ability to bind monoclonal antibodies. The absence of correlation between the antigenic properties of nucleoprotein and glycoproteids has been registered. Variability of some antigenic sites has been analyzed. The human epidemic strains of influenza virus are different in ability to bind monoclonal antibodies from the viral strains that are connected with animals in nature or laboratory practice.     

Properties of the erythrocyte receptors for influenza C virus.

Properties of the receptor for influenza C virus were studied. Although the receptor for influenza C virus on chicken erythrocytes was destroyed by the homologous virion, neuraminidase activity could not be detected in any of the influenza C virus strains tested. The receptor activity of chicken erythrocytes for influenza C virus was diminished by formaldehyde treatment but not by periodate oxidation. There was a considerable variation in the pattern and the titer of hemagglutination of influenza C virus when human erythrocytes of different blood types were used; the virus agglutinated most type B erythrocytes but not type A erythrocytes. By using human type B erythrocytes, differences among strains of influenza C virus in the hemagglutinating activity were also demonstrated. These results showed that both the receptor for and the receptor-destroying activity of influenza C virus were completely different from those of influenza A or B virus and also that carbohydrates were not involved in the receptor for influenza C virus.     

Kinetic studies on the sialidase of three influenza B and three influenza A virus strains

Sialidase of influenza virus type A has been extensively studied through structural and kinetic approaches. However, sialidase of influenza virus type B has been less investigated. In this work, we have studied the activity and some properties (optimal pH, K_M, V_max, thermal stability) of sialidase in three influenza virus strains of type B (circulating in the period 1983–86) and also the activity and properties of sialidase from three virus strains of type A circulating at the same period of time.The results show that the activity and the V_max was always higher for sialidase of type A viruses relative to those values of type B. Differences were also found for optimal pH and, in some cases, for thermal stability of the sialidase between strains belonging to the influenza viruses type A and B. However, the behaviour for the sialidase in all strains was very similar towards two competitive inhibitors. Thus, it could be suggested that the evolution pattern of the sialidase of both types of influenza viruses determines some modifications which result in a higher efficiency for sialidase of some strains of influenza virus type A, but maintaining in the two types of viruses a similar behaviour towards competitive inhibitors.Dedicated to Professor Maurice Leclerc by one of us (J.A.C.) on the occasion of his retirement.     

Effect of strain differences on the potency testing of rabies vaccines in mice

Antigenic differences between several strains of rabies virus, namely CVS, SAD and Flury (LEP) strains, were studied in cross-challenge experiments or cross-neutralization tests performed on sera of mice immunized with vaccines containing each strain. A typical wild fox virus strain was also included as challenge virus. The strain differences affected the relative potencies of the three vaccines in the European Pharmacopoeia mouse protection test for veterinary rabies vaccines, in that higher antigenic values were obtained when the vaccine strain was homologous to the challenge virus. This observation was confirmed by neutralizing antibody induction in mice.     

Structural dynamics of strains of a hepatitis B virus population in the Ukraine and its etiological prognosis

Changes in the population structure of influenza B virus in the Ukraine since 1980 has been studied. New strains of the virus have been identified and the epidemic potentials of different strains have been compared. The data on the drift mechanism of the origin of the intermediate strains of influenza B virus have been observed. A suggestion on the etiological prognostication of the epidemic process has been made.     

Comparative analysis of variable regions in the genomes of variola virus

Nucleotide sequences of two extended segments of the terminal variable regions in variola virus genome were determined. The size of the left segment was 13.5 kbp and of the right, 10.5 kbp. Totally, over 540 kbp were sequenced for 22 variola virus strains. The conducted phylogenetic analysis and the data published earlier allowed us to find the interrelations between 70 variola virus isolates, the character of their clustering, and the degree of intergroup and intragroup variations of the clusters of variola virus strains. The most polymorphic loci of the genome segments studied were determined. It was demonstrated that that these loci are localized to either noncoding genome regions or to the regions of destroyed open reading frames, characteristic of the ancestor virus. These loci are promising for development of the strategy for genotyping variola virus strains. Analysis of recombination using various methods demonstrated that, with the only exception, no statistically significant recombinational events in the genomes of variola virus strains studied were detectable.     

海南岛两个虫媒病毒分离物的初步鉴定

本文报告,1985年夏从海南岛采集的6种蚊子中,分离到4株乙型脑炎病毒和38株非乙脑病毒,其中两株(HN8和HN99)为甲组虫媒病毒。二者抗原性非常相近,对乳小白鼠脑内、腹腔和皮下接种部有较强的致病力,能在多种组织培养细胞上增殖并产生病变,能在鸡胚纤维母细胞上形成空斑,能凝集多种动物红细胞,血凝pH范围为5.75～6.4,最适pH为5.75或6.0,血凝素在4～37℃均较稳定,血凝素对福尔马林敏感。病毒呈球形,有包膜,直径60～65nm,属RNA病毒,对热、酸、乙醚和紫外线均敏感。血清学鉴定表明这两株病毒只与甲组虫媒病毒抗体有反应,尤其与MAY病毒抗原性关系较密切。同年从当地人、畜血清中检查了HN99病毒抗体,其阳性率为:健康人14％,猪23％,山羊35％。另外还与北京的M4株病毒作了初步比较,并对新毒株及我国其它有关毒株的分类学地位提出了初步看法。     

Comparative analysis of RNA genomes of mouse hepatitis viruses.

The RNA genomes of various murine hepatitis virus (MHV) strains were studied by T1-oligonucleotide fingerprinting analysis with regard to their structure and sequence relationship. It was found that the MHV particles contained only positive-stranded 60S RNA which had a "cap" structure at its 5' end. No negative-stranded RNA was found. It was also shown that most of the MHV strains had diverged quite extensively in their genetic sequences. However, MHV-3, a hepatotropic strain, and A59, a nonpathogenic strain, were found to have very similar oligonucleotide fingerprinting patterns. Yet, each of them contained two to four specific oligonucleotides. The MHV-3-specific oligonucleotides were conserved in almost all of the hepatotropic MHV strains studied. In contrast, two of the A59-specific oligonucleotides were absent from the genomes of all hepatotropic strains. These findings suggest that these unique oligonucleotides might be localized at the genetic region(s) associated with viral pathogenicity or other biological properties of the virus. Comparison of viral structural proteins also suggests that MHV-3 and A59 are more closely related than other MHV strains. The significance of these findings is discussed.     

兔出血症病毒四个分离株的病毒多肽和血清学关系研究

使用PEG-DS两相系统和超离心提纯的兔出血症病毒(RHDV)四个分离株病毒,再经Sepharose 4B柱层析进一步提纯后,得到较纯的病毒粒子,回收率可达70％以上。应用常规双向免疫扩散试验,交叉血凝抑制试验和酶联免疫吸附试验(ELISA)对四个不同地区分离株间的血清学关系进行了比较研究。结果表明实验中的四个分离株病毒均属同一血清型。SDS-PAGE结果表明,这四个分离株病毒均含有四条多肽,分子量为28—64KD。各株病毒多肽的分子量和各多肽在病毒粒子总蛋白中所占比例略有差异。因此四个分离株的RHDV在蛋白结构上可能存在地区差异。     

Investigation of the incidence of influenza A viraemia caused by virus strains circulating among children in 1968 - 1977.

Nineteen strains of Type A influenza virus isolated from the blood of small children in 1968--77 were studied. The investigation of the strains in HAIR with antisera to the antigenic components of the strains in HAIR with antisera to the antigenic components of the strains A/Hong-Kong/68,A/Anglia/72, A/Port Chalmers/73 and A/Victoria/75 made it possible to demonstrate antigenic "drive" of the haemagglutinin in the years 1968--1977 and to divide the strains into 4 varieties. A high sensitivity to inhibitors was observed in all the strains isolated. The study of pathogenicity and toxicity of the strains revealed viraemia in the strains isolated during the 1972--1973 epidemic and the subsequent epidemics with the absence of pathogenicity and toxicity for white mice. Regular finding of viraemia coincided in time with increased thermostablty of the haemagglutnin in the strains under study.     

Properties of Simian Virus 40 Rescued from Cell Lines Transformed by Ultraviolet-Irradiated Simian Virus 40

Simian virus 40 (SV40) strains have been rescued from various clonal lines of mouse kidney cells that had been transformed by ultraviolet (UV)-irradiated SV40. To learn whether some of the rescued SV40 strains were mutants, monkey kidney (CV-1) cells were infected with the rescued virus strains at 37 C and at 41 C. The SV40 strains studied included strains rescued from transformed cell lines classified as "good," "average," "poor," and "rare" yielders on the basis of total virus yield, frequency of induction, and incidence of successful rescue trials. Four small plaque mutants isolated from "poor" yielder lines and fuzzy and small plaque strains isolated from an "average" and a "good" yielder line, respectively, were among the SV40 strains tested. Virus strains rescued from all classes of transformed cells were capable of inducing the transplantation antigen, and they induced the intranuclear SV40-T-antigen, thymidine kinase, deoxyribonucleic acid (DNA) polymerase, and cellular DNA synthesis at 37 C and at 41 C. With the exception of four small plaque strains rescued from "poor" yielders, the rescued SV40 strains replicated their DNA and formed infectious virus with kinetics similar to parental SV40 at either 37 or 41 C. The four exceptional strains did replicate at 37 C, but replication was very poor at 41 C. Thus, only a few of the rescued virus strains exhibited defective SV40 functions in CV-1 cells. All of the virus strains rescued from the "rare" yielder lines were similar to parental SV40. Several hypotheses consistent with the properties of the rescued virus strains are discussed, which may account for the significant variations in virus yield and frequency of induction of the transformed cell lines.     

草鱼出血病混合感染的嗜水气单胞菌的分离、鉴定与理化特性

从患出血病草鱼的肝脏病灶中分离筛选出2株致病菌。取病鱼样品组织过滤液接种CIK细胞、培养, 电镜下观察到细胞质中含有草鱼呼肠孤病毒样颗粒和包涵体, 病毒颗粒大小65 nm~ 70 nm, 包涵体0.46 μm~1.81 μm。人工回归感染实验显示分离的菌株及细胞毒悬液均能使草鱼致病死亡。对分离菌株进行细胞形态学、理化特性分析及药敏试验, 初步判定所分离的2株菌均为嗜水气单胞菌。进一步对菌株进行DNA分子鉴定, 结果显示2株菌的16S rRNA基因、促旋酶亚单位蛋白(gryB)基因均与GenBank上的嗜水     

The etiological structure of the morbidity from influenza and other ARDs on the territory of Russia in the season of 1997-1998

The antigenic properties of 51 strains of influenza virus A(H1N1), isolated in different cities of Russia during the epidemic of 1998, were studied. Most of these strains (49) proved to be similar to virus A/Bern/07/95 in the antigenic structure of hemagglutinin, but 2 strains isolated in Ulan-Ude were found to be closely related to new antigenic variants of this virus: A/Beijing/262/95 and A/Fukuoka/c7/98. The analysis of the antigenic structure of influenza-like diseases (ILD) in different cities of Russia revealed that adenoviruses causing up to 10.9-14.6% of all acute respiratory virus infections dominated at the pre- and post-epidemic periods. RS-viruses, parainfluenza viruses of types 2 and 3 circulated during the whole season (their proportion was 5.1-6.6%). The intensity of the circulation of influenza viruses A(H1N1) and A(H3N2) increased, starting from January, and continued till April 1998; its peak was observed in February-March in most of the cities of Russia (up to 37.5-41.6% according to the results of immunofluorescent diagnostics and 53-73% of ILD according to the results of the hemagglutination inhibition test). The occurrence of influenza B during this season was very low.     

Properties of current influenza A (H1N1) virus strains and the characteristics of the epidemics they induce

Three epidemics of influenza A (H1N1) occurring in 1977, 1979 and 1981 were studied. These epidemics were found to be gradually dying down, which was manifested by progressively decreasing morbidity rate, the frequency and intensity of seroconversions, as well as by a decrease in the duration of the epidemic period. Changes in the biological properties of influenza A (H1N1) virus were accompanied by changes in its antigenic properties. The drift of neuraminidase in the influenza A (H1N1) virus of 1981 towards increased relationship with neuraminidase in the virus of 1952 was observed, while hemagglutinin in the strains of each of these two groups retained its individual character.     

Correlation between germ tube production, phospholipase activity and serotype distribution in Candida albicans

One-hundred and thirteen Candida albicans strains isolated from patients infected by the human immunodeficiency virus (HIV) and twenty five from HIV-negative individuals were studied. The C. albicans strains isolated from different sites of the body were tested for germ-tube (GT), phospholipase production and serotype. The results obtained indicate that the serotype A was predominant in all the groups except for the vaginal strains. No correlation was observed between phospholipase activity and serotype distribution. Germ tube (GT) production was higher among the serotype B strains. A positive correlation between GT induction and phospholipase activity was observed only for the isolates from the oral cavity. It is possible that the correlation between phospholipase activity and high GT production in C. albicans strains can facilitate the penetration through the mucosa.     

Comparison of strain susceptibility to experimental sialodacryoadenitis in rats

Wistar, Sprague-Dawley, and Long-Evans outbred rats, and the Fischer344 inbred strain were inoculated intranasally with 10(3) TCID50 of sialodacryoadenitis virus at approximately 9 weeks of age. Paired animals were killed at 2-day intervals post inoculation up to 2 weeks, then at 20 days. A comparison of strain susceptibility to sialodacryoadenitis virus was made using the following criteria: histopathology, immunofluorescent microscopy, serology and serum amylase activity. All four strains were susceptible to sialodacryoadenitis virus. The disease was frequently subclinical, although typical lesions were observed on histopathology. Focal bronchitis, bronchiolitis and pneumonitis were observed histologically during the acute stages of the disease. Immunohistochemistry was performed on trypsin-treated, paraffin-embedded sections, and viral antigen was readily demonstrated in salivary and lacrimal glands during the early stages of the disease. A rise in serum amylase was observed, and it was correlated with the first appearance of lesions in the salivary glands. Based on serology and immunofluorescence microscopy, the appearance of detectable antibody to sialodacryoadenitis virus, and the rate of viral clearance from infected glands, the course of the disease was similar in the four strains studied.     

Comparative analysis of west nile virus strains isolated from human and animal hosts using monoclonal antibodies and cDNA restriction digest profiles

The West Nile (WN) virus strains isolated in Bangui, Central African Republic (CAR), from patients with hepatitis were analysed comparatively with the prototype WN virus strain and 7 WN strains previously isolated from birds (2 strains), mosquitoes (3 strains) and ticks (2 strains) in CAR.The comparison was based on two techniques: an epitopic analysis by indirect immunofluorescence assay using a panel of 9 monoclonal antibodies to WN virus, and an analysis of HaeIII and TaqI restriction digest profiles of cDNA to infected cell RNA.Similar results were obtained with both techniques: the 3 human strains were found to be identical to each other and identical or very close to mosquito and tick strains, whereas prototype WN virus and bird strains were significantly different from the human strains.As “classical” infections due to WN virus without hepatic involvement were also reported during the period of isolation of the arthropod strains, we concluded that the same virus subtype may have been the cause of different infection patterns. A new definition of the disease spectrum of WN virus, including the possibility of liver involvement, should be established.Clearly, the Egyptian prototype WN virus represents a different topotype. Bird strains also appear to be different from human and arthropod strains, raising the question of their transmissibility and pathogenicity for man, and of the role of birds in the natural cycle of WN virus.     

Complement fixation reaction in the typing of influenza viruses isolated in Rio de Janeiro]

The author studied by the complement fixation test the influenza virus strains isolated in Rio de Janeiro during the 1973 epidemic. He prepared immunesera in hamsters by the inoculation of the allantoic fluid from infected chick embryos with each of the 7 isolated strains and the standard strains. The soluble antigens were prepared with the allantoic fluid of infected chick embryos. The tests were identically positive with the A2/Hong Kong/68 and A2/England/72 antigens and negative with the B/Mass/66. The tests were type specific and the behaviour of the A2/Hong Kong/68 and the A2/England/72 and the 7 strains of the isolated viruses was almost the same. They fixed 3 or 4 units of complement. The variants PR8, FM1 and Asia fixed only 2 units of complement.