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PubMed1988

[Determination of the antigenic activity of diphtheria anatoxin in liquid and sorbed preparations using an erythrocyte diphtheria antigen (anatoxin) diagnostic agent].

On the basis of the experimentally established dependence of the degree of binding of diphtheria toxoid with standard diphtheria antitoxin on the duration of their joint incubation with the maximum binding occurring in 3-4 hours of incubation at 37 degrees C, the method of the in vitro determination of the antigenic activity of diphtheria toxoid in liquid and adsorbed preparations is proposed. The method is based on the principle of double binding with the use of diphtheria antigenic (toxoid) erythrocyte diagnosticum. The antigenic activity of diphtheria toxoid, evaluated by the degree of its maximum binding with diphtheria antitoxin, correlated with its antitoxin-binding activity in animal experiments and did not correlate with its flocculating activity. The antigenic activity of diphtheria toxoid in adsorbed preparations, evaluated by their maximum binding with standard diphtheria antitoxin, was shown to be closely related to the immunogenic potency of these vaccines in animals.

Adsorption↗
PubMed1984

Entry of diphtheria toxin into cells: possible existence of cellular factor(s) for entry of diphtheria toxin into cells was studied in somatic cell hybrids and hybrid toxins.

Ehrlich ascites tumor cells were found to be very insensitive to diphtheria toxin. We formed 37 hybrids from Ehrlich tumor cells and diphtheria toxin-sensitive human fibroblasts. The effects of diphtheria toxin on protein synthesis in those hybrids were examined. The hybrids were divided into three groups on the basis of toxin sensitivity. Group A hybrids were as sensitive to diphtheria toxin as human fibroblasts, Group C were as resistant as Ehrlich tumor cells, and Group B had intermediate sensitivity. Group A hybrids had diphtheria toxin-binding sites but Group B and C had no detectable binding sites. Elongation factor-2 of all the hybrids was susceptible to ADP-ribosylation by fragment A of diphtheria toxin. Cells of Group A and B became more sensitive to CRM 45 (cross-reacting material 45 of diphtheria toxin) after they were exposed to low pH (pH = 4.5). The resistance of Group C to CRM 45 was not affected by the same treatment. Group A and B hybrids and human fibroblasts had similar sensitivities to a hybrid toxin composed of wheat germ agglutinin and fragment A of diphtheria toxin, but Group C and Ehrlich tumor cells were resistant to this hybrid toxin. All the hybrids and Ehrlich tumor cells were more sensitive to a hybrid toxin composed of wheat germ agglutinin and subunit A of ricin than were human fibroblasts. On subcloning of Group B hybrids, one Group C hybrid was obtained, but no Group A hybrid. These facts suggest that Ehrlich ascites tumor cells differ from human fibroblasts in the expression of a factor(s) that is involved in entry of fragment A of diphtheria toxin into the cytoplasm after the toxin binds to its surface receptors.

Adenosine Diphosphate Ribose↗
PubMed2004

Evaluation of diphtheria convalescent patients to serve as donors for the production of anti-diphtheria immunoglobulin preparations.

AIMS: The study was conducted to evaluate the possibility of selecting convalescent diphtheria patients to serve in emergency situations as donors for the production of anti-diphtheria immunoglobulin. To select suitable donors, the criterion of an antitoxin titer >/=3.0 IU/ml was used. In addition, the effects of treatment and the effect of immunization with diphtheria toxoid on the level of anti-diphtheria toxin antibodies were evaluated. SCOPE: Three groups of diphtheria patients were included in the study. The first group (n = 23) consisted of patients who had a basic antibiotic treatment, with or without serotherapy using horse antitoxin and/or human immunoglobulin. The second group (n = 12) comprised patients examined immediately after the onset of disease. The immunological history of this group was not known. The third group (n = 20) included patients with a known immunization history, treated only with antibiotics but having received a booster immunization with diphtheria toxoid. Antitoxin titers were measured using the toxin binding inhibition (ToBI) assay. CONCLUSIONS: In the first group, 47.8% (11/23) of the patients had a diphtheria antibody titer >/=3.0 IU/ml. For most of them, however, the antibody titers could have resulted from treatment with exogenous antibodies from horse antitoxin or human immunoglobulin (18/23). Only two of the 11 high-titer subjects had received antibiotics only. Among the second group, only two (16.76%) of the patients had an antibody titer of >/=3.0 IU/ml. In the third group 50% (10/20) of the patients showed an antibody titer of >/=3.0 IU/ml prior to vaccination, and therefore could be directly considered as donors. Three weeks after booster vaccination, 70% (14/20) had an antibody titer of >/=3.0 IU/ml and 1 year after booster vaccination, 28.6% (2/7) of the subjects still had titers of >/=3.0 IU/ml. In 40% of these patients, a decrease was observed 3-4 weeks after the booster dose. It was concluded that convalescent diphtheria patients could be considered as donors in an emergency situation, since approximately half of them showed antitoxin titers of >/=3.0 IU/ml.

Adolescent↗
PubMed2000

Epidemic diphtheria in the Newly Independent States of the Former Soviet Union: implications for diphtheria control in the United States.

The re-emergence of diphtheria in the Newly Independent States of the former Soviet Union in the 1990s raised global awareness of the potential for resurgent disease in countries with long-standing immunization programs. In the United States, the large population of susceptible adults and the possibility of a reintroduction of toxigenic strains of diphtheria create a setting in which diphtheria could spread. In addition, at least one focus of continued circulation of endemic toxigenic Corynebacterium diphtheriae has been identified. Few physicians now have expertise in the diagnosis and treatment of persons with diphtheria, and laboratory capacity is lacking throughout the country. These concerns highlight the importance of maintaining high levels of age-appropriate diphtheria toxoid vaccination, surveillance, accessible and reliable laboratory testing, and training of health care providers. Although the risk of resurgence of diphtheria in the United States is low, public health authorities must ensure that the capacity to recognize, diagnose, and control diphtheria is maintained.

Age Factors↗
PubMedDate not supplied

[Corynebacterium diphtheriae nontoxigenic strain carrying the gene of diphtheria toxin].

Among 828 C. diphtheriae nontoxigenic cultures isolated in different region of Russia in 1994-2002, 114 cultures (13.8%) had the gene of diphtheria toxin (gene tox) and were thus called nontoxigenic tox-carrying (NTTC) strains. All NTTC strains were found to belong to biovar mitis and formed neither normal, nor "defective" diphtheria toxin. The most of NTTC strains (94%) belonged to ribotype "Moskva", not occurring among C. diphtheriae toxigenic strains. The incapacity of NNTC strains of forming diphtheria toxin was caused by mutation: the deletion of one nucleotide which led to the shift of the open reading frame and to the formation of the stop codon. The results of these studies are indicative of the fact that a sufficiently homogeneous and isolated group of C. diphtheriae nontoxigenic strains is spread in Russia. These strains carry the nonexpressing gene of diphtheria toxin and are of no epidemic importance in diphtheria infection.

Codon, Terminator↗
PubMed2000

Effect on diphtheria immunity of combined tetanus and diphtheria booster vaccination in adults.

The effect of a single booster injection of an adult formulation of a combined diphtheria-tetanus vaccine (Td) on diphtheria-specific immunity was evaluated. The booster injection, containing 2 IU diphtheria toxoid per dose, was given as part of the surgical wound management for adults with open soft tissue injuries. Diphtheria antitoxin concentrations were determined in serum samples from 534 patients (199 women and 335 men, aged 18-70 years) using an enzyme immunoassay and a tissue culture toxin neutralization assay. Seroimmunity against diphtheria toxin was classified at three levels: susceptibility, basic protection, and full protection against the toxic manifestations of the disease. Before vaccination, 27.1% of the subjects were susceptible to diphtheria, 26.5% had basic protection, and 46.4% were fully protected. Six weeks (minimum 25 days, maximum 98 days) after a single booster injection, 89.7% of the subjects achieved full protection against diphtheria, and only 3.9% had antitoxin levels below the protective level. The median increase from the prevaccination to postvaccination antitoxin concentration was found to be 14-fold (4.4-47; quartiles Q25 to Q75). The change in antitoxin levels after revaccination was higher in older age groups (P< 0.001), whereas neither sex (P = 0.86) nor the country of previous immunization with a different national immunization schedule (P=0.61) had a significant influence on the revaccination effect. Systemic adverse reactions were rare, and local reactions of clinical significance were reported in only 1.9% of subjects.

Adolescent↗
PubMed1976

A study of the isolation of Corynebacterium diphtheria from clinical cases of diphtheria.

Throat swabs from 1000 clinical cases of diphtheria were studied for isolation of C. diphtheria; only 21.4% were found to be positive. Most of the cases were between 1 to 4 years of age followed by 5 to 8 years. No cases were found below 8 months of age. The throat swabs taken from another 22 clinical diphtheria patients were immediately cultured at patients bed side and 63.6% were found to be positive for C. diphtheria. Time between the collection and plating the specimen was considered to be one of the main factors in the variation of the percentage isolation of C. diphtheria. From all KLB positive cases on direct smear, C. diphtheria could not be isolated on culture. Also, from all cases having definite patch(es) over tonsil(s), C. diphtheria could not be isolated. All strains were found to be sensitive against commonly used antibiotics.

Age Factors↗
PubMed2000

Ukraine, 1992: first assessment of diphtheria vaccine effectiveness during the recent resurgence of diphtheria in the Former Soviet Union.

A case-control study in Ukraine provided the first data on the field effectiveness of Russian-produced vaccine during the 1990 diphtheria resurgence in the former Soviet Union. For each of 262 diphtheria cases <15 years of age who were reported from January through October 1992, 2 controls, matched by age and clinic, were selected. The effectiveness of three doses of diphtheria vaccine was 98.2% (95% confidence interval: 90.3-99.9). Among controls, 84% had received three or more vaccinations by 2 years of age. These results suggest that the following five hypothesized causes of the outbreak appeared unlikely: appearance of a new "mutant" diphtheria strain, low potency of the Russian-produced diphtheria vaccine, inadequate cold chain, poor host immunogenicity due to radiation exposure from Chernobyl, and low routine childhood vaccination coverage. It is concluded that initial priority for scarce resources for controlling this outbreak should be placed on vaccination of persons susceptible to diphtheria (e.g., adults) rather than revaccination of children.

Adolescent↗
PubMed1979

Diphtheria toxin-binding glycoproteins on hamster cells: candidates for diphtheria toxin receptors.

Diphtheria toxin-binding glycoproteins of high molecular weight (greater than 100,000) were identified on the surface of lymph node and thymus cells from hamsters, a diphtheria toxin-sensitive species. These diphtheria toxin-binding glycoproteins also interacted with CRM197 protein, which possesses toxin-blocking activity, but not with diphtheria toxoid, fragment A of diphtheria toxin, or cholera toxin, all of which lack toxin-blocking activity. These observations are consistent with the hypothesis that the detected diphtheria toxin-binding glycoproteins are involved in intoxication of cells by this toxin and possibly serve as the plasma membrane receptors for diphtheria toxin.

Animals↗
PubMed2001

Induction of neutralizing antibodies against diphtheria toxin by priming with recombinant Mycobacterium bovis BCG expressing CRM(197), a mutant diphtheria toxin.

BCG, the attenuated strain of Mycobacterium bovis, has been widely used as a vaccine against tuberculosis and is thus an important candidate as a live carrier for multiple antigens. With the aim of developing a recombinant BCG (rBCG) vaccine against diphtheria, pertussis, and tetanus (DPT), we analyzed the potential of CRM(197), a mutated nontoxic derivative of diphtheria toxin, as the recombinant antigen for a BCG-based vaccine against diphtheria. Expression of CRM(197) in rBCG was achieved using Escherichia coli-mycobacterium shuttle vectors under the control of pBlaF*, an upregulated beta-lactamase promoter from Mycobacterium fortuitum. Immunization of mice with rBCG-CRM(197) elicited an anti-diphtheria toxoid antibody response, but the sera of immunized mice were not able to neutralize diphtheria toxin (DTx) activity. On the other hand, a subimmunizing dose of the conventional diphtheria-tetanus vaccine, administered in order to mimic an infection, showed that rBCG-CRM(197) was able to prime the induction of a humoral response within shorter periods. Interestingly, the antibodies produced showed neutralizing activity only when the vaccines had been given as a mixture in combination with rBCG expressing tetanus toxin fragment C (FC), suggesting an adjuvant effect of rBCG-FC on the immune response induced by rBCG-CRM(197). Isotype analysis of the anti-diphtheria toxoid antibodies induced by the combined vaccines, but not rBCG-CRM(197) alone, showed an immunoglobulin G1-dominant profile, as did the conventional vaccine. Our results show that rBCG expressing CRM(197) can elicit a neutralizing humoral response and encourage further studies on the development of a DPT vaccine with rBCG.

Animals↗
PubMed2006

Ultrasound examination of extensive limb swelling reactions after diphtheria-tetanus-acellular pertussis or reduced-antigen content diphtheria-tetanus-acellular pertussis immunization in preschool-aged children.

OBJECTIVE: The aim of this study was to determine the site, extent, and resolution of tissue involvement when extensive limb swelling occurred in the injected limb for children who received diphtheria-tetanus-acellular pertussis or reduced-antigen content diphtheria-tetanus-acellular pertussis vaccine at 4 to 6 years of age. METHODS: Children who had experienced an injection site reaction at 18 months of age were assigned randomly to receive an intramuscular injection of either reduced-antigen content diphtheria-tetanus-acellular pertussis vaccine or diphtheria-tetanus-acellular pertussis vaccine between 4 and 6 years of age. Children who developed extensive limb swelling were recruited for assessment by clinical examination; ultrasound studies of the affected and opposite (control) arms were performed 24 to 48 hours after immunization and 48 to 96 hours later. RESULTS: Twelve children with extensive limb swelling were enrolled in the study. Ultrasound examinations demonstrated swelling of both the subcutaneous and muscle layers of the vaccinated arm. Ultrasound assessment showed that the swelling exceeded the clinical measurements of skin redness and swelling. Subcutaneous and muscle tissues expanded to 281% and 111% of the tissue thicknesses of the control arm, respectively. Repeat ultrasound examinations after 48 to 96 hours showed considerable resolution of muscle swelling, compared with subcutaneous tissue swelling. There was no significant difference in the extent of swelling detected between children who received diphtheria-tetanus-acellular pertussis vaccine and those who received reduced-antigen content diphtheria-tetanus-acellular pertussis vaccine. CONCLUSION: Extensive limb swelling reactions after diphtheria-tetanus-acellular pertussis or reduced-antigen content booster immunizations involved swelling of subcutaneous and muscle tissues with swelling and duration more marked in subcutaneous tissue.

Antigens, Bacterial↗
PubMed1999

[Diphtheria and infections caused by Corynebacterium diphtheriae in 1997].

INTRODUCTION: Diphtheria is a reemerging disease. Two epidemics recently occurred in Algeria and Independent States Community, not so far from Europe. Imported cases were diagnosed in contiguous European countries. This review focuses on the data obtained from these epidemics, with particular emphasis on new clinical forms of Corynebacterium diphtheriae infections. CURRENTS KNOWLEDGE AND KEY POINTS: Sore throat with membranes is no longer the only clinical feature of diphtheria. However, patients' management is identical, with combination of antibiotics, injection of specific antisera, and immunization of patients' close contacts and relatives. French and American sero-epidemiological studies showed that antibody levels does not provide protection, particularly in the elderly. Adult populations would therefore be at risk every 10 years. Recent advances in molecular biology led to the development of gene amplification with polymerase chain reaction, that may be used for the detection of the toxin gene. They also promoted epidemiological surveys of circulating strains via ribotyping. Although this technic evidenced predominant strains in the various countries, genotypes encountered during an epidemics may differ. Besides diphtheria which has apparently been eradicated in France, systemic infections with non-toxigenic strains of C diphtheriae, such as endocarditis, septicemia and arthritis, are evenly diagnosed. FUTURE PROSPECTS AND PROJECTS: A French national reference center for C diphtheriae has been recently created. This center collects most of the strains isolated in France, clinical data and assesses the toxigenicity of bacteria, allowing strict epidemiological survey.

Adult↗
PubMed2003

Immune response to a diphtheria and tetanus toxoid administration in a three-dose diphtheria tetanus whole-cell pertussis/enhanced inactivated poliovirus vaccination schedule: a 7-year follow up.

The immune response to diphtheria and tetanus toxoid components of a combined diphtheria tetanus whole-cell pertussis/enhanced inactivated poliovirus (DTwP/eIPV) vaccine, administered in a three-dose schedule to infants at 2, 3 1/2 and 10 months of age and followed by a booster at the age of 8 years, was compared with the immune profile of a group of children at the same ages given the customary DTwP vaccine schedule at 2, 4, 6, and 12 months of age and a booster at the age of 8. Diphtheria- and tetanus-antitoxin titers were measured in parallel enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA). After the reinforcing dose given at 10 months of age, diphtheria antitoxin concentrations of > or = 0.01 IU/ml were found in 100% of infants in the study group, 91.7% of whom reached a titer of > or = 0.1 IU/ml and a geometric mean titer (GMT) of 0.40 and 0.93 IU/ml in ELISA and RIA, respectively. At 3 and 6 years of age, diphtheria antitoxin values of > or = 0.01 IU/ml were detected in 100 and 94% of children with GMT of 0.043 and 0.024 IU/ml, respectively. Seropositivity and GMT values indicative of protection were measured by both ELISA and RIA after the booster at the age of 8 years. Similar results were found in the control group, although the GMT tended to be higher. A good correlation between results obtained by ELISA vs. RIA was evident throughout. Priming at 2 and 3 1/2 months with diphtheria and tetanus antitoxin, as a component of a DTwP program, and reinforcing 6 months later induced an immune response indicative of protection against the diseases, which persisted up to the age of the booster recommended at school entry.

Child↗
PubMedDate not supplied

Pediatric diphtheria and tetanus toxoids-adsorbed vaccine: immune response to the first booster following the diphtheria and tetanus toxoids vaccine primary series.

Diphtheria and tetanus toxoids (DT) vaccine should be given to children at 2, 4 and 6 months of age when there are contraindications to the administration of pertussis vaccine. We have previously reported that such children develop protective antitoxin antibody levels to diphtheria and tetanus antigens. This follow-up study evaluates the decay in antitoxin antibody levels and the booster response elicited to DT antigen when a fourth dose is given at approximately 18 months of age. Twenty-three children receiving DT vaccine were compared to 38 receiving diphtheria and tetanus toxoids-pertussis (DTP) vaccine. The prebooster antibody titer to diphtheria and tetanus at approximately 18 months of age had declined below the recommended protective level in one child who had received DT vaccine and in three children who had received DTP. Following the 18-month booster dose of DT and DTP vaccine, all of the children had protective titers to diphtheria and tetanus toxin. These results suggest that the adjuvant effects of pertussis vaccine are not required to achieve adequate immunization to diphtheria and tetanus when currently available DT vaccine is used in early childhood.

Antibodies, Bacterial↗
PubMed2005

Molecular characterization of diphtheria toxin repressor (dtxR) genes present in nontoxigenic Corynebacterium diphtheriae strains isolated in the United Kingdom.

Nontoxigenic strains of Corynebacterium diphtheriae represent a potential reservoir for the emergence of toxigenic C. diphtheriae strains if they possessed functional diphtheria toxin repressor (dtxR) genes. We studied the predominant strain of nontoxigenic C. diphtheriae circulating in the United Kingdom to see if they possessed dtxR genes and ascertain whether they were functional. A total of 26 nontoxigenic C. diphtheriae strains isolated in the United Kingdom during 1995 and 4 nontoxigenic strains isolated in other countries were analyzed by PCR and direct sequencing to determine the presence and intactness of the dtxR genes. The functionality of the DtxR proteins was assayed by testing for the production of siderophore in medium containing high and low concentrations of iron. PCR amplification and sequence analysis of the dtxR genes revealed four variants of the predicted DtxR protein among the nontoxigenic strains isolated in the United Kingdom. Production of siderophore in medium containing a low concentration of iron and repression of siderophore production in medium containing a high concentration of iron demonstrated that in all the strains the dtxR genes were functional. These findings demonstrate that, if lysogenised by a bacteriophage, nontoxigenic strains circulating in the United Kingdom could produce toxin and therefore represent a potential reservoir for toxigenic C. diphtheriae.

Amino Acid Sequence↗
PubMedDate not supplied

[Diphtheroids and nontoxigenic Corynebacterium diphtheriae in the etiology of diphtheria].

The review raises a problem of cooperation between a laboratory and clinics for diphtheria diagnosis. According to scientific literature nontoxigenic diphtheroids cause different nosocomial infections of immunocompromised patients. Nontoxigenic Corynebacterium diphtheriae may cause such systemic infections as septic arthritis and endocarditis in people belonging to unsecured strata of the society. A toxin which can be produced not only by C. diphtheriae but also by diphtheroids is the sole reason of diphtheric inflammation. The role of the C. diphtheriae nontoxigenic strains should be elucidated by the improving of standard methods and introduction of the methods of molecular biology for the toxigenicity assay of diphtheria strains (e.g. polymerase chain reaction). But a complexity of gene expression and difficulties in distinguishing between the infection and the microorganism colonization of a vaccinated person reserve the last word in the diagnosis of diphtheria for a clinical physician.

Corynebacterium↗
PubMedDate not supplied

[Identification of Corynebacterium diphtheria biovar belfanti among circulating C. diphtheriae strains in Ukraine].

The biochemical test of the reduction of nitrates to nitrites made it possible to identify 5.2% of strains belonging to biovar belfanti among 135 C. diphtheriae strains, initially classified within biovar mitis. Out of 7 identified C. diphtheriae belfanti strains, 2 toxigenic strains were isolated from multiple foci diphtheria. According to the results of the polymerase chain reaction, 1 out of 5 non-toxigenic strains had tox gene. All C. diphtheriae belfanti strains were found to have pronounced capacity for adhesion to sheep and human red blood cells. At the stage of the extinction of diphtheria epidemic the practical identification of C. diphtheriae belfanti strains is necessary, as increased adhesion in combination with toxigenic properties may probably promote for bacteria of this biovar to take the leading role at the period of sporadic morbidity.

Animals↗