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E Shlyakhov

Publications and source records attributed to E Shlyakhov.

12 recordsLinked to original sources
PubMed2004

Evaluation of Bacillus anthracis extractable antigen for testing anthrax immunity.

Three extractable Bacillus anthracis cell-wall-associated antigens were evaluated for potential use as skin testing agents, and as possible candidates for in-vitro diagnosis of anthrax immunity. Anthraxin and a partially purified extractable antigen (EAP) were produced from avirulent B. anthracis strain 34F2 (Sterne). The thermoextractable antigen used for the Ascoli reaction was obtained commercially. Guinea-pigs were immunised and boosted several times subcutaneously with the Sterne live veterinary anthrax vaccine. Four weeks after the last booster dose, animals were skin-tested with the three antigens. Serum antibody levels were also determined by ELISA, and the in-vitro T-cell response was evaluated by [3H]-thymidine incorporation. EAP was the most active antigen in both the serological and cellular reactions. EAP also elicited a distinct positive skin reaction in animals immunised with B. anthracis. The data obtained in this preliminary study indicated that extractable cell-wall antigens obtained from the vegetative form of B. anthracis may be used for skin tests and in-vitro testing of specific humoral and cell-mediated anthrax immunity.

Animals↗
PubMed1996

Evaluation of the anthraxin skin test for diagnosis of acute and past human anthrax.

A skin test for the diagnosis of human anthrax was evaluated as an alternative to bacteriological confirmation of human anthrax, which is possible in 10-40% of cases within the first three weeks of the disease only. The anthraxin skin test, which detects anthrax cell-mediated immunity, was positive in 81.8% of cases in the first three days of the disease, and in 97-99% of cases in the next two to three weeks. The positivity rate was 98.5% in the first 1.5 months of convalescence, 92.8% in the next 3 years, 82.8% in the following 4 to 15 years, and 72.7% 16 to 31 years after recovery. Thus, the anthraxin skin test appears to be a valuable method for early diagnosis of acute anthrax as well as the only method available for retrospective diagnosis of human anthrax.

Acute Disease↗
PubMed1996

[Delayed hypersensitivity in man after booster anthrax vaccination].

The purpose of this study was to ascertain the need for boosters after administration of STI anthrax vaccine. Postvaccination dynamics was assessed by observing the intradermic reaction of anthraxine. The study included 138 subjects vaccinated 15 months earlier by subcutaneous injection or 128 subjects vaccinated 24 months earlier by aerosol inhalation. Subjects were tested using the anthraxine test in separate groups on D2, D7, D15, D90, D180, and D365 after administration of the booster via the same route as the primary vaccination. Immediately before administration of the booster residual positive skin reactions were observed in 14.3% of subjects in the subcutaneous vaccination group and 8.3% of subjects in the aerosol vaccination group. After the booster, the proportion of subjects with positive skin reactions increased rapidly. The proportion of positive skin reactions after the booster was not statistically different from the proportion after the primary vaccination. This study provides scientific evidence supporting the need for boosters after anthrax vaccination and demonstrated an absence of sensitization by anthraxine during tests to evaluate response kinetics in subjects after primary vaccination. Several questions remain to be answered concerning the optical booster dose, the most effective timing, and the value of acellular vaccines.

Administration, Inhalation↗
PubMed1996

[Vaccines against anthrax in animals, from Louis Pasteur to our day].

The authors outline the history of vaccination against anthrax in animals, from the end of the 19th century to the present time. The three main steps in the production of specific vaccines are described in detail: production of vaccines from live, encapsulated bacteria, followed by vaccines from live, unencapsulated bacteria and, finally, subunit vaccines. Advantages and disadvantages of these three types of vaccine, some of which are still in use today, are described and discussed.

Animals↗
PubMed1995

Prevalence of antibodies against hepatitis A virus among new immigrants in Israel.

Israel, located in a region endemic for hepatitis A virus (HAV), recently absorbed a large population of immigrants who came from the former USSR. To assess the risk of high morbidity in this population a serosurvey of HAV antibodies was undertaken. Serum samples were collected from 965 new immigrants, of whom 664 came from the European, non-endemic region, and 301 from the Asian and Caucasian endemic regions of the former Soviet Union. They were compared to 240 Israelis. Each population was divided into six age groups: 1-9, 10-19, 20-29, 30-39, 40-49, and 50 years of age and older. The Asian/Caucasian immigrants and the Israeli population were found to share similar characteristics. In both groups, antibodies to HAV (anti-HAV) were present in the 1-9-year-old age group and reached maximum prevalence (90% and 86.7%, respectively) in the 20-29-year-old age group. In contrast, among the European immigrants anti-HAV was first found in the 10-19-year-olds and peaked (93%) in the age group of 50 years and older. It is concluded that immigrants originating from the European part of the former USSR may require vaccination against hepatitis A.

Adolescent↗
PubMed1995

Rapid bioassay for detection of Bacillus anthracis in mice.

A rapid-bioassay method (RBA) of diagnosing anthrax was developed in mice. A standard RBA consisted of intraperitoneal inoculation of a suspected culture or of a suspension of raw infected animal tissues in four pairs of mice. At 60, 120 and 180 min after inoculation, two mice were killed and smears and impression smears were made from the peritoneal fluid, heart blood, spleen, liver, and kidneys, and then fixed, stained and microscopically examined. Encapsulated rods seen in microscopy confirmed the diagnosis. The remaining pair of mice was kept for a 10-day observation period and served as a control. In the experiments described in this study, RBA showed a high efficiency. A vegetative culture of 18-20 h of Bacillus anthracis growth demonstrated encapsulation in mice as early as 120 min after inoculation; a culture of 3-5 or 6-12 h of growth showed encapsulation at 60 min. Old spores gave encapsulation at 180 min, but, if previously plated for 6 h, encapsulation was observed as early as 60 min after inoculation. Inoculation of raw infected tissues gave positive results at 120 min. As compared with the challenged controls, no deviations between the results of RBA and the final diagnosis of anthrax were observed, but RBA appears to be 7-17 times more rapid. Some variations of the standard RBA are also suggested.

Animals↗
PubMed1994

[Post anthrax vaccine delayed hypersensitivity. II--delayed hypersensitivity in humans vaccinated against anthrax].

To detect cell immunity characterized by delayed postvaccination hypersensitivity to anthrax in man and assess its dynamics, vaccination using unencapsulated live anthrax vaccine was performed in 668 healthy volunteers. Vaccination was performed either by scarification (n = 172), subcutaneous injection (n = 202), or low-dose (n = 202) or high-dose (n = 83) inhalation. The anthraxin intradermal tests were performed in each patient at various times during the year following vaccination (D7, D15, D90, D180, D365). This study confirm that, regardless of the mode of administration, the vaccine induces cell-mediated immunity in man, as determined by positive anthraxine skin test. The incidence of positive tests decreases with time regardless of the mode of vaccination. After one year, the test remained positive in 34.8% of subjects vaccinated by subcutaneous injection, 37.5% vaccinated by low-dose inhalation, 34.2% vaccinated by high-dose inhalation, and 22.4% vaccinated by scarification. These findings are in agreement with those obtained in clinical epidemiological studies documenting the effectiveness of encapsulated live anthrax vaccine in man.

Administration, Inhalation↗
PubMed1994

[Delayed hypersensitivity after anthrax vaccination. I--Study of guinea pigs vaccinated against anthrax].

To evaluate delayed hypersensitivity after anthrax vaccination, an Anthraxin skin test was performed in 682 guinea pigs at various times after immunization with veterinary unencapsulated active anthrax vaccine. Results were compared with those obtained in unimmunized control guinea pigs (n = 216), in guinea pigs that received a non-immunizing dose of live vaccine (n = 183) and in guinea pigs inoculated with inactivated vaccine (n = 120). Anthraxin skin tests were positive in the first postvaccination days. The incidence and intensity of positive tests peaked between two weeks and one month after vaccination and then gradually decreased during the first year. Study of resistance of guinea pigs to an inoculum at a lethal dose of a virulent strain of Bacillus anthracis showed a close correlation between positive tests and resistance. These findings demonstrate development of cell-mediated immunity after anthrax vaccination. The Anthraxin skin test should have practical applications for the production of vaccines and for evaluation of the immune status of vaccinated livestock [corrected].

Animals↗
PubMedDate not supplied

Anthrax post-vaccinal cell-mediated immunity in humans: kinetics pattern.

Seven groups (2596 subjects) were vaccinated with a human live anthrax vaccine (HLAV) by three different routes (scarification, subcutaneous and aerosol). The vaccinees were tested for anthrax cell-mediated immunity using the "Anthraxin" skin test at 7, 15, 30, 90, 180 and 365 days following vaccination. The kinetic pattern obtained from all groups, shows a significant, five-phased curve: phase I (2-6 days post-vaccination) shows a slow increase in positive Anthraxin skin reactions. Phase II (7-15 days post-vaccination) shows an exponential rise to a maximum at day 15. Phase III (16-30 days post-vaccination) shows a decrease to day 30. Phase IV (31-90 days post-vaccination) leads to a relative restoration of the positive skin reactions. During phase V (91-365 days post-vaccination) there is a continuous decrease in positive Anthraxin skin reactions. The loss of the skin test reaction on day 30 is a characteristic feature of post vaccination anthrax cell-mediated immunity. It may be due to a blockade of macrophages by lethal anthrax toxin released by the multiplying vaccine strain. Epidemiological observations of HLAV protective rates correlate with the phases of the skin reaction kinetics.

Adolescent↗
PubMedDate not supplied

[Retrospective diagnosis of anthrax by intradermal reaction].

The authors report a detailed study of utilization of a skin test with anthraxin to perform a retrospective diagnosis of anthrax in humans who suffered from anthrax 45 days to 31 years after recovery. For a total of 884 persons studied, 762 showed a positive skin test (86.2%). This index was 92.8% for persons tested 45 days to 3 years after convalescence, 82.8% 4 to 15 years after convalescence and 72.7% 16-31 years after recovery. The site of the primary carbuncle on the skin of the fingers, hands, face and neck gave an index of positivity (88.2%) statistically greater (p = 99%) than by localization of the carbuncle on arms, forearms, trunk and legs (77.3%).

Adult↗