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PubMed1998

[Evaluation of the usefulness of the ELISA method for determining the level of enterovirus antibodies in serum and cerebrospinal fluid].

The usefulness of the methods was compared: complement fixation test (CFT), neutralization test (NT) and ELISA IgG and IgM against enteroviruses for the evaluation of specific immune reaction in sera and cerebrospinal fluid (CSF) samples of patients with confirmed enterovirus infections. The criteria were established for the assessment of ELISA results in rapid diagnosis of enterovirus neuroinfections. The criteria accepted by the producer lowered the sensitivity of the method and the possibility of recognition of local synthesis of antibodies in the CNS. The use of serum negative in CFT and negative CSF as reference for the determination made possible using of that kit for rapid diagnosis of neuroinfections. The modified ELISA IgG test makes possible determination of antibodies in CSF and serum, and accepting the generally recognized criteria for local production of antibodies in the CNS the ELISA test makes possible rapid diagnosis of neuroinfections which is not possible by other methods.

Antibodies, Viral↗
PubMed1975

[Formation and persistence of latex-agglutination-inhibiting IgG- and IgM-antibodies in rabbits inoculated with poliomyelitis, Coxsackie and encephalomyocarditis viruses (author's transl)].

The formation and presistence of virus specific IgG- and IgM-antibodies produced in rabbits after a single dose of poliomyelitisvirus, coxsackievirus or encephalomyocarditisvirus were tested comparatively by latex-agglutination-inhibition test, hemagglutination-inhibition test and neutralization test. The animals were immunized either intravenously alone or with Freund's complete adjuvant. The IgM-antibodies were only detectable for a short time by the three tests. In the IgG-fraction and in the unfractionated serum the neutralizing antibodies persisted without any loss in titer during the period observed, whereas the latex-agglutination-inhibiting and hemagglutination-inhibiting antibodies showed a significant decrease. The hemagglutination-inhibiting antibodies required 23 weeks (Figure 5), the latex-agglutination-inhibiting antibodies 7 weeks (without Freund's complete adjuvant; Figure 1 and 3) or about 16 weeks (with Freund's complete adjuvant; Figure 2, 4 and 5) respectively to decline to 25% of their maximum titer.

Animals↗
PubMed1979

Intratypic serodifferentiation of poliomyelitis virus strains by strain-specific antisera.

Strain-specific antisera against non-Sabin-like and Sabin-like poliovirus strains were prepared by cross-absorption of the antisera with the heterologous strain. Isolates from different parts of the world were differentiated intratypically as non-Sabin-like and Sabin-like strains with the aid of these sera in the immunodiffusion test and neutralization test. In comparison with other marker tests, intratypic differentiation can be performed more easily. Further, fewer intermediate strains were found and, in our opinion, the results are more reliable.

Humans↗
PubMed1975

[Mild course of botulinus intoxication (author's transl)].

Botulinus poisoning generally ends fatally after an only short course, mild forms being rare. In four members of a family who had eaten deep-frozen grilled sausages symptoms of botulinus poisoning developed, predominantly marked by disturbances of the autonomic nervous system. The course was so mild that hospitalization was not necessary nor was specific antitoxin administration. All clinical symptoms had disappeared after nine weeks. But special clinical and neurophysiological studies (electromyography, pupillography, electroencephalography) demonstrated abnormalities for very much longer. Botulinus poisoning was proven in animal tests and neutralization tests with botulinus antitoxin. The epidemiology, source of infection, and clinical symptoms suggest botulinus type B poisoning.

Adult↗
PubMed1993

[Detection of Rhodococcus equi antibodies in human serum].

The authors investigated in sera of patients with pneumonia the presence of antibodies against the equi factor Rhodococcus equi. For examination they used agar immunodiffusion and a test for neutralizing the equi factor. Some 110 sera of different donors were examined. In agar immunodiffusion they used the equi factor as antigen either in the separated form or equi factor produced by the growing strain of R. equi. The neutralization test was implemented on agar media with red blood cells sensitized with staphylococcal beta-haemolysin. In all serological tests 27 sera reacted positively only by precipitation 30 sera, while 53 sera did not contain antibodies against the equi factor. The authors discuss the impact of the assembled results and the possible participation of R. equi in human disease.

Actinomycetales Infections↗
PubMed1995

Serologic survey of neotropical bats in Guatemala for virus antibodies.

Neotropical bats were collected from different life zones in Guatemala in 1983 and 1984 to determine the presence and distribution of antibody against 10 viruses. Bats were collected with mist nets at 13 sites in eight departments and 332 serum specimens were obtained for testing for neutralizing (N) antibody by the plaque-reduction neutralization test. Eighty-seven (26%) of the 332 bats from 16 (38%) of 42 bat species sampled were serologically positive for five of six arboviruses and for two other viruses tested. Antibodies against Venezuelan equine encephalitis (VEE) variant I-A/B, eastern equine encephalitis, western equine encephalitis, St. Louis encephalitis, vesicular stomatitis, Tacaribe, and Rio Bravo viruses were detected in resident species of bats. However, N antibodies against the enzootic strain of VEE (Mena II, variant I-E) or Nepuyo viruses were not detected.

Animals↗
PubMed1982

Antigenic groupings of 90 rhinovirus serotypes.

We have completed production in rabbits of potent antisera to the 90 classified rhinovirus serotypes by using methods previously described (M. K. Cooney and G. E. Kenny, Proc. Soc. Exp. Biol. Med. 133:645-650, 1970). Systematic testing by neutralization tests has revealed significant numbers of cross-relationships among rhinovirus types, some of which have already been reported. Herein, our observations are compared with cross-reactions reported in National Institutes of Health reference guinea pig antisera. Also, original rhinovirus isolates, representing serotypes known to be antigenically related to other rhinoviruses, were tested against rabbit antisera to the related serotypes. These tests revealed extensive antigenic variation among isolates identified as rhinovirus 12:78 or 36:58, which are reciprocally related pairs, 41, reciprocally related to 13, and 67, which is related to both 9 and 32. If the rhinovirus serotypes were grouped according to antigenic relationships, 50 types could be included in 16 groups.

Animals↗
PubMed2000

An epizootic of hemorrhagic disease in white-tailed deer in Missouri.

As part of a white-tailed deer (Odocoileus virginianus) survival study in Missouri (USA) we were actively monitoring 97 radio-collared deer when 8 (8%) died. This mortality, which occurred from 20 August to 23 September 1996, consisted of five adult females, two yearling females and one yearling male. Based on the seasonality of this mortality and the isolation of epizootic hemorrhagic disease virus (EHDV) serotype 2 from one of these animals, we believe that these losses resulted from an epizootic of hemorrhagic disease. The remains of five unmarked deer that may have died from HD also were found on the study area during this same period. During the fall following this mortality, we tested serum from 96 deer taken by hunters in the immediate area. Fifteen (16%) were positive for EHDV or bluetongue virus (BTV) antibodies as determined by agar gel immunodiffusion tests. Serum neutralization test results indicated that previous infections were caused by EHDV virus serotype 2. Based on these data, and assuming that there was no prior exposure to EHDV serotype 2 in this population, the exposure rate for this epizootic was 24% of which 8% died. We noted hoof interruptions in only two of the 96 deer sampled. During this mortality event, the Missouri Department of Conservation received no reports of dead deer, and without the radio-monitored animals the event would have been undetected.

Animals↗
PubMed1996

[Immunity to diphtheria in the Croatian population in 1994].

The large outbreak of diphtheria in the former SSSR countries, which has been linked, among others, to low herd immunity, has led us to determine the level of this immunity in the Croatian population in view to undertake, if necessary, extra prophylactic measures (vaccination). For the purpose, C. diphtheriae serum antibody levels were determined in persons aged from 20 to above 60 years and coming from four major Croatian towns (Zagreb, Rijeka, Osijek and Split). A commercial ELISA test and neutralization test (NT) on guinea pig were used. Whereas 223 sera were examined with ELISA, only 51 underwent NT. Both tests showed herd immunity to decline gradually with age, ELISA also revealing a wide variation range of antibody concentrations by individual age groups (Table 1). There was not a single serum sample below the "critical" level of 0.01 IU/ml. in Table 2, ELISA results are classified in three groups by antibody level: up to 0.01 IU/ml, between 0.01 and 0.09 and above 0.09 IU/ml, i.e. as unprotected, partially protected and protected persons. Such grouping of findings shows that not one of the subjects belongs to the first category, that most of them belong to the third (68%), as well as that the latter are passing into the second with growing age. It is concluded that by carrying out the mandatory immunization programme, in force in Croatia, it has been possible to attain and to sustain a high level of herd immunity. Hence there is no need for booster immunizations at older age.

Adult↗
PubMed1999

Evaluation of tick-borne encephalitis DNA vaccines in monkeys.

Tick-borne encephalitis is usually caused by infection with one of two flaviviruses: Russian spring summer encephalitis virus (RSSEV) or Central European encephalitis virus (CEEV). We previously demonstrated that gene gun inoculation of mice with naked DNA vaccines expressing the prM and E genes of these viruses resulted in long-lived homologous and heterologous protective immunity (Schmaljohn et al., 1997). To further evaluate these vaccines, we inoculated rhesus macaques by gene gun with the RSSEV or CEEV vaccines or with both DNA vaccines and compared resulting antibody titers with those obtained by vaccination with a commercial, formalin-inactivated vaccine administered at the human dose. Vaccinations were given at days 0, 30, and 70. All of the vaccines elicited antibodies detected by ELISA and by plaque-reduction neutralization tests. The neutralizing antibody responses persisted for at least 15 weeks after the final vaccination. Because monkeys are not uniformly susceptible to tick-borne encephalitis, the protective properties of the vaccines were assessed by passive transfer of monkey sera to mice and subsequent challenge of the mice with RSSEV or CEEV. One hour after transfer, mice that received 50 microl of sera from monkeys vaccinated with both DNA vaccines had circulating neutralizing antibody levels <20-80. All of these mice were protected from challenge with RSSEV or CEEV. Mice that received 10 microl of sera from monkeys vaccinated with the individual DNA vaccines, both DNA vaccines, or a commercial vaccine were partially to completely protected from RSSEV or CEEV challenge. These data suggest that DNA vaccines may offer protective immunity to primates similar to that obtained with a commercial inactivated-virus vaccine.

Animals↗
PubMed2002

Production and immunogenic efficacy of botulinum tetravalent (A, B, E, F) toxoid.

A tetravalent (type A, B, E and F) toxoid was produced and its efficacy and safety were assessed. The toxoid preparation was inoculated from two to five times to 15 healthy adult volunteers participating in botulinum toxin research. The serum samples taken from the toxoid recipients were titrated for the antitoxin potencies by enzyme-linked immunosorbent assay (ELISA) and the neutralization test. The neutralizing and ELISA titers were too low to correlate each other. The mean neutralization titer of four recipients in 9 months after three doses of toxoid was about 0.1IU/ml for each of the four types, whereas, the one receiving five doses possessed a higher titer. Since the amount of the toxin handled in laboratory work is usually not so large, three or more doses of the present toxoid will bestow sufficient immunity on the workers participating in botulinum research. Nevertheless booster injections might be desirable to those at higher risk, handling the toxin of a high concentration.

Adult↗
PubMed1980

Purification and properties of chromosomally mediated beta-lactamase from Citrobacter freundii GN7391.

Both a penicillinase and a cephalosporinase are present in a strain of Citrobacter freundii (GN7391) resistant to beta-lactam antibiotics. The penicillinase was identical to the type Ia penicillinases (Type III by Richmond classification), mediated by Rms212 and R-TEM. A cephalosporinase, typical of enterobacteriaceae chromosomal beta-lactamase (Type I by Richmond classification), was purified from the strain. It gave a single protein band on polyacrylamide gel electrophoresis and immunoelectrophoresis; the pI was 8.6 and its molecular weight was approximately 38 000. Cysteine was not found among its amino acids. The specific activity was 388 units (mg protein)-1 for the hydrolysis of cephaloridine, and the optimal pH was 8.0. Rabbit antiserum obtained against the purified enzyme showed cross-reaction with cephalosporinases produced by strains of Enterobacter cloacae in a neutralization test.

Amino Acids↗
PubMed1992

Method for detection of simian immunodeficiency virus neutralizing antibodies using a noncommercial antigen capture enzyme-linked immunosorbent assay.

A neutralization test (NT) using a noncommercial antigen capture enzyme-linked immunosorbent assay (ELISA) to detect simian immunodeficiency virus (SIV) growth in vitro was developed. The capture antibody was a mixture of purified macaque anti-SIV immunoglobulin G (IgG) and a monoclonal antibody to SIV p27. Captured antigens were detected by using purified macaque anti-SIV IgG conjugated to horseradish peroxidase. The NT reliably and sensitively detected differences when various amounts of SIV were used with positive and negative control macaque sera. Dilutions of sequential sera from a macaque (Macaca nemestrina) that had been experimentally infected with SIV were tested for neutralizing antibody with 300 50% tissue culture infective doses of SIV. In this macaque, neutralizing activity and anti-SIV IgG levels in serum (detected by ELISA) increased with time after SIV inoculation, and high IgG titers were required in serum before neutralization occurred in vitro. This simple NT, which detects the presence of SIV serum neutralizing antibodies at a low cost, will be useful for investigating the role of neutralizing antibodies in the SIV-infected macaque model for AIDS.

Animals↗
PubMed1986

Rift Valley fever surveillance in mobile sheep flocks in the Nile Delta.

Rift Valley fever (RVF) surveillance was carried out in the Nile Delta by monitoring mobile and stationary sheep flocks for antibodies to RVF virus. Sheep are known to be susceptible to RVF virus infection and experienced severe morbidity in 1977 and 1978 when RVF was epidemic in Egypt. Four hundred six sheep in 32 flocks were surveyed during 1984. Twenty-four sheep from 7 flocks had antibodies to RVF virus detected by hemagglutination inhibition and plaque reduction neutralization tests. Antibodies were found primarily in sheep greater than 3 years of age, although 1- and 2-year-old sheep were included in the sample. No seroconversion was observed among 177 seronegative sheep that were bled successively for a period of 10 months. These results indicate that epizootic RVF was probably not present in the Nile Delta during 1984.

Animals↗
PubMed1988

Human infections with Tensaw virus in south Florida: evidence that Tensaw virus subtypes stimulate the production of antibodies reactive with closely related Bunyamwera serogroup viruses.

Maguari virus, a member of the Bunyamwera serogroup (family Bunyaviridae, genus Bunyavirus) has not been isolated north of Trinidad. Anecdotal information from other investigators has indicated the presence of antibody to Maguari virus in human residents of south Florida. We attributed such antibody to either cross-reactivity with Tensaw virus, the only Bunyamwera serogroup virus known in south Florida, or to cross-reactivity to an antigenic subtype or variant of Tensaw virus. Five strains, identified as Tensaw virus when they were isolated from mosquitoes collected in south Florida more than 20 years ago, were retrieved from storage. They were compared by serum dilution-plaque reduction neutralization tests with Bunyamwera serogroup prototypes Tensaw, Maguari, Cache Valley, and Tlacotalpan viruses. The south Florida isolates were shown to be most closely related to prototype Tensaw virus and most distantly related to prototype Maguari virus. One isolate could not be distinguished from prototype Tensaw virus, and the other 4 appeared to be subtypes of prototype Tensaw virus. More than 300 serum samples from humans in south Florida were tested for neutralizing antibody to prototypes Tensaw and Maguari viruses and to 3 of the field isolates. Thirteen had antibody to prototype Tensaw virus only, 19 to prototype Maguari virus only, and 39 to both. Antibody to all but 6 of these 71 was attributed to infection with Tensaw virus, to a subtype of Tensaw virus, or to travel or birth outside the United States. It is likely that those with antibody to Maguari virus only had been infected with yet another subtype of Tensaw virus, although another, undiscovered, Bunyamwera serogroup virus may exist in south Florida.

Animals↗
PubMed1978

Dengue viral antigens in host cell membranes.

Membranes from type 2 dengue virus (DEN-2) infected BHK cells, when used as immunogen, elicit antibodies detectable by complement fixation, hemagglutination inhibition and plaque reduction neutralization tests with suckling-mouse-brain-derived DEN-antigens. Membrane fractions from infected cells separated by sucrose density gradient centrifugation were employed as antigen in serological tests with anti-DEN-2 infected suckling mouse brain hyperimmune mouse serum and hyperimmune mouse ascitic fluid. Antigen (s) capable of fixing complement were associated with all membrane fractions, including the plasma membrane, whereas antigen capable of reacting with antihemagglutinin was largely confined to the two membrane bands consisting of (1) a mixture of rough and smooth endoplasmic reticulum (2) predominantly rough endoplasmic reticulum.

Antigens, Viral↗
PubMed1985

A serological survey for Bhanja and tick-borne encephalitis viruses in sheep of eastern Slovakia.

755 sheep from 41 farms in the districts of Trebisov, Michalovce, Humenné and Roznava in the East Slovakian region were investigated on the presence of antibodies to Bhanja (neutralization test) and tick-borne encephalitis (haemagglutination-inhibition test) viruses. In respective districts 2.2%, 0.4%, 1.7% and 26.7% of animals (total 5.3%) were found to be positive on Bhanja virus, 4.4%, 1.5%, 1.7% and 5.0% (total 2.6%) on tick-borne encephalitis (TBE) virus. The considerable infection rate in sheep with Bhanja virus in the district of Roznava (mean 26.7%-on one farm as high as 63.9% serologically positive animals) can be explained by the local occurrence of the tick Haemaphysalis punctata, the main vector of this virus in Europe. The serologic screening conducted indicates a low activity of natural foci of TBE in eastern Slovakia today, and confirms the existence of a natural focus of infection with Bhanja virus in the district of Roznava. Recent circulation of Bhanja virus is indicated by antibodies detected in several one-year-old sheep.

Animals↗
PubMedDate not supplied

Antigenic relatedness of pigeon herpes encephalomyelitis virus to other avian herpesviruses.

Pigeon herpes encephalomyelitis virus (PHEV) was compared with seven avian herpesviruses for antigenic relatedness using monospecific antisera and the indirect fluorescent-antibody (IFA), agar-gel-immunodiffusion, and serum-neutralization tests. No antigenic relationship was detected between PHEV and Marek's disease virus, turkey herpesvirus, infectious laryngotracheitis virus, and duck enteritis virus. A common precipitating antigen was detected between the PHEV and pigeon herpesvirus (PHV), owl herpesvirus (OHV), and falcon herpesvirus (FHV). These four viruses also cross-reacted in the IFA test. Weak neutralizing activity was detected only between PHV antiserum and PHEV. These results suggest that the PHEV should be classified as a herpesvirus related to, but distinct from, the PHV-OHV-FHV group of viruses with which it shares common antigens.

Animals↗