[Insertional Inactivation of Virulence Operon in Population of Persistent Bordetella pertussis Bacteria].

Avirulent B. pertussis bacteria containing IS elements in the bvgAS operon were detected during the study of whooping cough patients and bacilli carriers. The present work is devoted to the study of the accumulation dynamics and the mechanisms of generation of persistent forms of the B. pertussis bacteria in lower monkeys as the most adequate model for extrapolation ofthe experiment results to humans. By means of the real-time PCR method, it was established that the B. pertussis bacteria lived more than three months in the upper respiratory tract after a single intranasal monkey infection; the period was reduced to 14-28 days during repeated infection. An increase in the portion of B. pertussis Bvg mutants in the population to tens of percent from the total number of registered bacteria was registered. The experimental confirmation ofthe development and accumulation of avirulent B. pertussis Bvg mutants during the development of the infectious process was obtained. Further study of the composition of the B. pertussis persistent bacteria population at different stages of the disease will make it possible to formulate new approaches to the whooping cough diagnostics and prevention and creation of fundamentally new drugs.

[To the 50th anniversary of the discovery of the simian hemorrhagic fever and SHF virus].

The results of the study of SHF and virus SHF for the last period since their discovery are summed up. It was established that the source of this infection fatal for Asian macaques are African monkeys--virus carriers. There is still a danger of the occurrence of epizootics in Primatological Centers at the importation of these monkeys for research. The importance of the obtained experimental SHF in macaques was emphasized. This model is unique, safe and adequate. It is necessary for further study of pathogenesis and evaluation of the means of pathogenetic therapy of HF dangerous to human health.

[Experimental whooping cough of nonhuman primate].

Despite considerable success in study of Bordetella pertussis virulence factors, pathogenesis of whooping cough, duration of B. pertussis bacteria persistence, types and mechanisms of immune response are still keep underinvestigated. It can be explained by the absence ofadequate experimental animal model for pertussis study. Our study estimates clinical and laboratory parameters of whooping cough in non-human primates of the Old World in the process of intranasan infection by virulent B. pertussis bacteria. Also the duration of B. pertussis bacteria persistence in animals was investigated. 14 animal units of 4 species of non-human primates of the Old World were used for intranasal infection. The examination of infect animals included: visual exploration of nasopharynx, thermometry, clinical and biochemical blood analyses, identification ofB. pertussis, using microbiologic and molecular genetic analyses, estimation of innate and adoptive immune factors. The development of infectious process was accompanied by generation of B. pertussis bacteria, catarrhal inflammation of nasopharyngeal mucosa, leucocytosis, hypoglycemia specific for pertussis, and activation of innate and adaptive immunity for all primates regardless of specie were seen. While repeated experimental infection in primates single bacterial colonies were registered during only first week after challenge. It occurs like the absence of inflammation of nasopharyngeal mucosa and the lack of laboratory marks of whooping cough, recorded after first challenge. The evident booster effect of humoral immunity was observed. As a model for investigation of B. pertussis bacteria persistence and immune response against whooping cough we suggest the usage of rhesus macaque as more available to experiments.

[Secondary infection with hepatitis A in Rhesus monkeys after experimental inoculation]. / Povtornaia infektsiia gepatita A u makak rezusov pri éksperimental'nom zarazhenii.

Time course of specific humoral immunity is studied in 186 Macaca mulatta spontaneously infected with hepatitis A virus (HAV). Immunity parameters are characterized quantitatively and qualitatively and their similarity to those in human hepatitis A (HA) is demonstrated. Repeated HA was reproduced in 12 seropositive Macaca mulatta infected with HAV-MR in high doses. The disease was characterized either by periodical virus release with feces for 1.5-2 months (10(4) ID50) or by that together with a notable increase of SGPT for 1.5-4 months (10(5) ID50) without morphologic changes in the liver, indicating a lesser severity of infection. Reinfection was associated with a rapid expressed increase of class G anti-HAV titers to 20,000-74,000 and no class M antibodies. Virus release with feces in the absence of the main specific diagnostic criterion, IgM antibodies, may be epidemiologically significant. Hyperimmune sera from monkeys with reinfection are intended to be used as the antibody component of immune diagnostic agent.

[Characteristics of experimental models of hepatitis A in Papio hamadryas]. / Kharakteristika éksperimental'nykh modelei gepatita A na pavianakh gamadrilakh.

Hepatitis A (HA) was induced in 14 Papio hamadryas by strain VHA-PH isolated from this species of monkeys with spontaneous infection, strain VHA-MM isolated from Macaca mulatta, and a unique strain VHA-H3 isolated from a patient; this latter strain is pathogenic for Macaca mulatta in experiment. All infected seronegative animals developed a disease with virological, serological, biochemical, and morphological signs characteristic of human HA, but the duration of these signs manifestation varied. Virus in the feces and an increased level of SGPT were detected periodically starting from days 3-26 to 24-135, and in 4 monkeys even later (up to days 163-238). Morphologic changes in the liver, typical of acute hepatitis, were observed from days 10-46 to days 16-130. Strain VHA-H3 is less pathogenic for papios. HA models on Papio hamadryas infected with strains VHA-PH and VHA-MM can help solve many research and practical problems.

[Preparation and characteristics of cultured strains of hepatitis A virus from humans and monkeys]. / Poluchenie i kharakteristika kul'tural'nykh shtammov virusa gepatita A ot cheloveka i obez'ian.

Cultural strains of hepatitis A virus (HAV) have been isolated from spontaneously infected Macaca mulatta (HAV-MM), Papio hamadryas (HAV-PH), African green monkeys Cercopithecus aethiops (HAV-CA), and patients (HAV-H). The strains replicate in continuous cells lines AGMK, 4647, Vero, and FRhk-4. AGMK and 4647 cells are the most permissive at 32 degrees C. Virus propagation was not associated with the cytopathic effect and could be detected by enzyme immunoassay (EIA), immune electron microscopy (IEM), and molecular hybridization method (MHM). The morphological and antigenic properties of the above monkey and human strains did not differ in EIA and IEM with polyclonal antibodies and for one most conservative genome sites in the VP1 domain. Cultural strains retained their pathogenicity for monkeys. HAV strains are proposed to be used as HAV antigen in immunological tests and for hepatitis A induction in monkeys.

[An experimental study of immunity to hepatitis A in monkeys]. / Eksperimental'noe izuchenie immuniteta k gepatitu A na obez'ianakh.

In this work the experimental model of hepatitis A on monkeys, adequate to human hepatitis A, was used. Ten monkeys (6 Macaca mulatta and 4 Cercopithecus aethiops) were reinfected with different doses of hepatitis A virus (HAV) a year after recovery from spontaneous and experimental hepatitis A. The monkeys were completely resistant to the inoculation of the virus in moderate doses (10(3) ID50). The inoculation of HAV in large doses (10(4)-10(5) ID50) induced a mild form of this infection in the animals with a transient rise in the level of serum alanin aminotransferase and HAV shedding in feces, but in the absence of morphological changes in the liver. It should be specially pointed out that after the reinfection of monkeys virus shedding in feces was observed, which may be of great epidemiological importance. After reinfection the absence of IgM and a pronounced rise in the titers of IgC antibodies were observed.

[A trial of a hepatitis A cultured inactivated vaccine on rhesus macaques]. / Ispytanie kul'tural'noi inaktivirovannoi vaktsiny gepatita A na makakakh rezusakh.

In this work experimental model of hepatitis A virus (HAV) infection in macaques rhesus was used. In 6 seronegative monkeys immunized with the inactivated vaccine (3 injections of 0.3 micrograms of viral protein each at an interval of 1 month) pronounced antibody response was observed. The dynamics and titers of anti-HAV antibodies were similar to those in 5 rhesus macaques which received the active virus. But, in contrast to the latter, no IgM antibodies were detected in the immunized animals. Three months after the end of immunization the monkeys were resistant to challenge with a HAV strain pathogenic for humans (10(3) - 10(4) ID50). The monkeys had no morphological changes in the liver and no rise in the serum alanine-amino transferase activity, but exhibited transient excretion of the virus in feces, as well as stimulation of anti-HAV antibodies (in the absence of IgM antibodies). The vaccine under test proved to be safe, immunogenic and produced a protective effect.

[Spontaneous coronavirus infection in monkeys]. / Spontannaia koronavirusnaia infektsiia obez'ian.

A high level of the spread of coronavirus (CV) infection among hamadryas baboons and macaques of different species (about 50%), both resident in the animal house and imported, has been established. The tropism of CV to the gastrointestinal and respiratory tracts has been demonstrated. The course of spontaneous CV infection is accompanied by enterocolitis and/or pneumonia with periodic exacerbations, or takes the inapparent form. Cases of virus persistence have also been noted. Infected macaques exhibited an increase in the titers of antibodies to their own CV strain isolated from these animals, as well as to antigenically related human CV strain 0043. Spontaneous CV infection in monkeys may be used for solving some obscure problems of the pathogenesis and epidemiology of CV infection in humans.

[The experimental coronavirus infection of monkeys]. / Eksperimental'naia koronavirusnaia infektsiia obez'ian.

The coronavirus (CV) infection has been reproduced on monkeys (Macaca mulatta) for the first time. The strain CVRM 281, obtained from rhesus monkey who died of the spontaneous CV injection, has been used for the infection. The experimental CV infection has a chronic current with periodical relapses and virus persistence. Gastrointestinal tract (enterocolitis) and respiratory tract (pneumonia) are damaged exhibiting characteristic histological lesions. The monkey model of the CV injection can be used to solve obscure questions of human one.

[Experimental models of hepatitis A in macaques using viral strains isolated from man and monkeys]. / Eksperimental'nye modeli gepatita A na makakakh s ispol'zovaniem shtammov virusov, vydelennykh ot cheloveka i obez'ian.

Experimental hepatitis A (HA) models were obtained in macaca monkeys (15 M. fascicularis and 4 M. mulatta) by means of the strains of hepatitis A virus (HAV) isolated from the feces of a patient (HAV-H) and of spontaneously infected M. Mulatta (HAV-MM) and green monkeys Cercopithecus aethiops (HAV-CA). Irrespective of the strains used all seronegative macaca monkeys developed HA after intravenous-oral inoculation with the following patterns: elevation of the serum alanine aminotransferase level, HAV shedding in feces, seroconversion with the appearance of anti-HAV IgM and morphological changes in the liver characteristic of acute hepatitis. HAV in fecal samples and elevation of alanine aminotransferase were periodically detected. Periods of their discovery varied from 5-22 to 15-47 days and those of morphological changes in the liver from 9-24 to 40-83 days. The results of the experiments show that experimental HA models in Macaca monkeys are no less adequate than the previous ones developed in chimpanzees (Pan troglodytes), marmosets (Saguinus mystax) and owl monkeys (Aotus trivirgatus), but they are more readily available. Both strain HAV-H and strains from monkeys can be used for HA modelling. The models are expected to be used for studying yet unsolved problems of pathogenesis and immunogenesis, as well as for testing vaccines and antiviral drugs.

[The properties of simian coronavirus]. / Izuchenie svoistv koronavirusa obez'ian.

Properties of 20 coronavirus (CV) isolates obtained from spontaneously infected Papio hamadryas and rhesus monkeys were investigated. Two of them were selected as simian CV prototype strains-CVRM 281 (rhesus monkey) and CVP 250 (Papio hamadryas), and can be offered as candidates to the Coronaviridae family. They are closely related to each other, but differ in some biological properties and polypeptides. These strains belong to the 2nd antigen group of mammalian CV with the prototype strain HCV OC 43 but differ from the latter. The strain CVRM 281 induces experimental CV infection which can be used as a model for investigations of some obscure aspects of human infection. The properties of these viruses suggest their usefulness for diagnostic purposes.

[Spontaneous and experimental hepatitis A in Papio hamadryas]. / Spontannyi i éksperimental'nyi gepatit A u pavianov gamadrilov.

Data on high susceptibility of Papio hamadryas to HAV are presented. For the first time, P. hamadryas were shown to be able to respond to both natural and experimental infection developing the features typical of hepatitis A: increased aminotransferase activity, virus shedding in feces, production of anti-HAV IgG and IgM, histological liver lesions. An infection lingering for 3-4 months was observed, as well as a case of chronic experimental hepatitis A with relapse in 7 months of the disease. Virological evidence of HAV infection was obtained in both lingering and chronic disease. HAV-PH strain was isolated for the first time and is described at length. It was isolated from a baboon with spontaneous infection which did not differ from that in man by antigenic and morphological features. The virus replicated in continuous African green monkey kidney cell line (AGMK) and was pathogenic for P. hamadryas. The HAV-PH isolate can be used for modelling hepatitis A in P. hamadryas.

[Virus persistence in hepatitis A in monkeys]. / Persistentsiia virusa pri gepatite A obez'ian.

A long-term complex observation of 16 cynomolgus monkeys (Macaca fascicularis) and 8 African green monkeys (Cercopithecus aethiops) with spontaneous and experimental hepatitis A revealed two forms of the illness: acute and chronic. Some monkeys developed undulating chronic course of the disease consisting of 2-6 waves. Others developed relapses (1 to 3) which occurred within 2-4 or 6-11.5 months of the infection. The morphological changes in the liver persisted for 7-28 months. Alaninaminotransferase elevations in the blood and HAV shedding in feces were observed periodically for 7-20 months. HAV persistence was documented by radioimmunoassay, enzyme immunoassay, immune electron microscopy and molecular hybridization. Persisting HAV was shown to remain pathogenic for monkeys. Virological evidence of the etiological association of HAV with chronic infection and late relapses has been obtained for the first time.

[The chronic course of spontaneous and experimental hepatitis A in rhesus monkeys with viral persistence]. / Khronicheskoe techenie spontannogo i éksperimental'nogo gepatita A u makak rezusov s persistentsiei virusa.

The prolonged (up to 2 years) complex observation of 11 rhesus macaques (Macaca mulatta) with spontaneous hepatitis A and 14 rhesus macaques with experimental hepatitis A developing after their intravenous and/or oral infection with human hepatitis A virus (HAV). Both natural and experimental infection took a chronic course (15-18 months). In 13 monkeys showing morphological changes in the liver during the whole period of the disease elevated enzyme levels in the blood and virus shedding in feces were periodically observed. Only one monkey had acute hepatitis A which lasted 1.5 months. In 11 monkeys the disease took an undulating course with 1-2 relapses when virological, biochemical and morphological signs of the disease could be detected. Seroconversion was observed in all monkeys. Anti-HAV IgM antibodies were retained for not more than 6-7 months and total anti-HAV antibodies, during the whole period of observation. Relapses were found to induce no antibody formation. Evidence on the prolonged (up to 12-16 months) persistence of HAV in primates was obtained for the first time.

[Comparative morphology of spontaneous hepatitis A in lower Old World monkeys]. / Sravnitel'naia morfologiia spontannogo hepatita A u nizshikh obez'ian starogo sveta.

Detailed description of liver damage in two species of macaques (rhesus and fascicularis) and green monkeys with spontaneous hepatitis A (HA) induced by the virus similar to human hepatitis. A virus (HAV) is given. Evolution of histological changes was followed by serial liver biopsies. The picture of the hepatitis in the above monkey species resemble that of human NA as well as HA in other monkey species susceptible to HAV. Only in 8 of 21 monkeys the disease lasted for 2-5 months, others exhibited undulating and lingering course which lasted 8-19 months from the beginning of the infection. The lingering course of the infection was caused by HAV persistence in the host with its periodical elimination in faeces.