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PubMed1991

Immunity against diphtheria in the age group 15 to 25 years.

Levels of diphtheria antitoxin in 254 serum samples were estimated in subjects in the age group 15 to 25 years with no previous history of immunisation against diphtheria using indirect haemagglutination test. All the individuals showed more than 0.03 IU/ml of diphtheria antitoxin level. This indicates that the age group studied was not susceptible to diphtheria. No significant relationship could be, however, ascertained between diphtheria antitoxin level and epidemiological factors like age, area (rural/urban), socioeconomic status, family size, education status and religion.

Adolescent↗

PubMed1979

Immunity to tetanus and diphtheria in various age groups of the Polish population.

The concentration of tetanus and diphtheria antitoxins was determined in 279 sera of 18 to 81-year-old women and 509 sera of 22 to 46-year-old men. Tetanus antitoxin content was determined also in 246 samples of fluid from human placentas and 428 lots of commercial human normal immunoglobulins. Immunity to tetanus was clearly age-dependent: in younger age groups the percentage of immunized persons amounted to 90%-100%, in middle-age groups to about 80%, and at age above 60 to about 25%. The findings are in agreement with age-dependent incidence of tetanus, which has become now in Poland a disease primarily of older people. Two groups of the population are now protected against diphtheria: a younger group under 20, and an older one above 40. Immunity in younger age groups was induced by artificial immunization, and among older persons by natural immunization through contact with diphtheria bacilli during severe diphtheria epidemics in the past. Between these groups, gaps exist including 20-30 years of age, who are sensitive to diphtheria.

Adolescent↗

PubMedDate not supplied

[Diphtheria: apropos of an epidemic].

Since Ramon developed the anti-diphtheria anatoxin in 1924 widespread vaccination has almost eliminated diphtheria, but since the acquired immunity is anatoxic and not anti-bacterial, carriage of the causal agent Corynebacterium diphteriae remains possible. In 1990, 1214 declared cases of diphtheria inaugurated an epidemic which spread through Russia, Ukraine and neighboring countries and even reached a few subjects in Europe and North America. Mortality in Russia was 10.15 per 100000 cases in 1993. Higher rates were observed in children. The question is raised as to the level of protection in Western countries despite generalized vaccination programs. In France, a recent survey showed that only 49.3% of the 1004 subjects evaluated had complete protection and 20.4% had no protection at all. While 95% of young adults in the 15 to 24 age range were protected, the rate of protection was below one-third in subjects over 65. These results emphasize the importance of anti-diphtheria vaccination programs and continued surveillance in adult populations. Current French legislation requires vaccination before the age of 18 months but without any requirement for re-vaccination in adults. The current situation clearly demonstrates that the risk of a diphtheria epidemic still exists, even in our Western countries. To completely protect the population, the present vaccination policy should include re-vaccinations of the adult population every 10 years, as for tetanus. Use of a preparation containing a reduced dose of vaccine, given with the tetanus and polio booster shots, is to be recommended. Re-vaccination with DT or the reduced dose dT would also be indicated after injury instead of tetanus alone. Surveillance and typing of C. diphteriae strains isolated from clinical cases should also be maintained.

Child↗

PubMed1996

Update: diphtheria epidemic--New Independent States of the Former Soviet Union, January 1995-March 1996.

Epidemic diphtheria reemerged in the New Independent States (NIS) of the former Soviet Union, beginning in the Russian Federation in 1990 and affecting all 15 NIS by the end of 1994. Approximately 90% of all diphtheria cases reported worldwide during 1990-1995 were reported from the NIS (World Health Organization [WHO], unpublished data, 1996). During 1993-1994, WHO, partner organizations, and national ministries of health developed a strategy to control the epidemic with a priority goal of achieving coverage of >90% among persons aged > or = 3 years with a single dose of diphtheria toxoid through mass vaccination campaigns and achieving coverage for routine childhood vaccination (i.e., four doses of diphtheria and tetanus toxoids and pertussis vaccine by age 2 years) of >95%. This report summarizes data provided to WHO about the incidence of diphtheria and efforts to implement control measures in the NIS during 1995 and January-March 1996.

Commonwealth of Independent States↗

PubMed1996

Vero cell assay validation of an alternative to the Ph. Eur. diphtheria potency tests.

In the framework of the Biological Standardisation Programme of the European Pharmacopoeia Commission, in 1993 a collaborative study was organised for the validation of an alternative to the diphtheria in vivo challenge tests required by the Ph.Eur. monograph V.2.2.7. The alternative assay is based on the detection of neutralising antibodies in the sera from mice immunised with the vaccines to be tested (Vero cell assay). In the study this assay method was validated against intradermal and lethal challenge in guinea-pigs, performed in conformity with Ph.Eur. Therefore the potency currently on the European market, was assayed in parallel by the different assay methods. Seventeen laboratories, from eleven different countries, participated in the study. Three laboratories performed the intradermal challenge assay, while three other laboratories performed the lethal challenge assay. All seventeen laboratories performed the Vero cell assay. The results of the study suggest that the potency of the diphtheria component of both monovalent diphtheria vaccines and combined diphtheria-tetanus vaccines can be estimated adequately by means of the Vero cell assay. It does not yet seem possible for all combined diphtheria-tetanus-pertussis vaccines to replace a potency assay based on the protective capacity of a vaccine in guinea-pigs by the Vero cell assay. This may be due to an adjuvant effect of the pertussis component of the vaccine, in combination with the adsorbent used, which may be more pronounced in mice than in guinea-pigs and may also differ between different strains of mice.

Animal Testing Alternatives↗

PubMed1997

Diphtheria and tetanus immunity among blood donors in Toronto.

OBJECTIVE: To determine the diphtheria and tetanus antitoxin levels among blood donors in Toronto. DESIGN: Cross-sectional seroprevalence study. SETTING: Two fixed-site blood-donation clinics in Toronto from September to November 1994. PARTICIPANTS: Blood donors 20 years of age or older were eligible to participate; of the 781 eligible donors, 710 (90.9%) participated in the study. MAIN OUTCOME MEASURES: Diphtheria and tetanus antitoxin levels and factors associated with disease susceptibility, such as vaccination history, country of birth, age and sex. A diphtheria antitoxin level lower than 0.01 lU/mL and a tetanus antitoxin level lower than 0.15 lU/mL were considered nonprotective. RESULTS: Among the participants, 147 (20.7%) had a diphtheria antitoxin level in the nonprotective range, and 124 (17.5%) had a tetanus antitoxin level that was nonprotective. Increasing age and lack of written vaccination records were associated with susceptibility to the 2 diseases. Birth outside Canada was significantly related to tetanus susceptibility. CONCLUSION: Adults over 50 years of age who did not know their vaccination history were the least likely to be protected against diphtheria and tetanus. The greatest benefit of any immunization strategy would be gained by targeting this group.

Adult↗

PubMed2000

Epidemic investigation of diphtheria in the Republic of Armenia, 1990-1996.

While incidence rates of diphtheria steadily declined in Armenia after World War II, reemergence of the disease in 1990 brought about changes in public health practices and identified resource needs. The Armenian Ministry of Health (MOH) routinely collected diphtheria case reports, as a reportable health outcome. Diphtheria incidence rates increased from 0.02/100,000 in 1993 to 1/100,000 (36 cases) in 1994. The distribution of cases showed that the greatest number of illnesses and deaths occurred among persons 5-14 years old, yet incidence rates among persons 1-4 and 5-14 years old were similar (4. 4 cases/ and 4.3 cases/100,000, respectively). During 1990-1996, 9 (75%) of 12 cases who died and 18 (21%) of 84 cases who survived had not been vaccinated. The diphtheria epidemic in Armenia was an important, serious, and signal public health event. The Armenian MOH responded by revising immunization practices (1994), improving epidemic control measures (1995), and soliciting international resources (1992-1996).

Adolescent↗

PubMed2000

Epidemic diphtheria in the Kyrgyz Republic, 1994-1998.

The Kyrgyz Republic experienced a widespread diphtheria epidemic during 1994-1998. National diphtheria surveillance and vaccination coverage information were used to describe the course of the epidemic. The epidemic began in August 1994, reached a peak in 1995 with 704 cases (incidence rate: 15.4/100,000 population) and 30 deaths, and declined to an incidence rate of 4.0/100,000 during the first 8 months of 1998. Age-specific incidence was highest in 1995 among persons 15-19 and 20-29 years old. Three rounds of mass vaccination with tetanus and diphtheria toxoids for adult use (Td) were conducted; reported coverage was 69% in 1995 and >95% in 1996 and 1997. Reported routine vaccination coverage with three doses of diphtheria toxoid by age 12 months increased from 62% in 1989 to 98% in 1997. Mass vaccination of the adult population with Td and improvements in childhood vaccination coverage played a major role in controlling the epidemic.

Adolescent↗

PubMed2002

Report on the Sixth International Meeting of the European Laboratory Working Group on Diphtheria, Brussels, Belgium.

In addition to the Eastern European resurgence of diphtheria during the last decade, there has also been an emergence of infections caused by non-toxigenic Corynebacterium diphtheriae and non-toxigenic, toxin gene bearing C. diphtheriae. Given that these strains may manifest as symptomatic infections of differing degrees of severity, their clinical and epidemiological significance need to be assessed. The persistence of toxigenic and non-toxigenic C. diphtheriae in circulation, together with genotypic and biotype variability means that innovative measures to vaccinate populations are pertinent. The most effective method of protecting the currently most vulnerable population group (adults) is to implement a booster dose of vaccine amongst the adult populations. Furthermore, in combination with an efficient surveillance system, effective antibiotic prophylaxis and an up-to-date vaccination programme, serological studies needs to be maintained to monitor the immunity status of the population.

Adult↗

PubMed2000

Diphtheria in the Russian Federation in the 1990s.

A resurgence of diphtheria spread throughout the Russian Federation in the early 1990s; diphtheria had been well controlled, but circulation of toxigenic strains of Corynebacterium diphtheriae had persisted since the implementation of universal childhood vaccination in the late 1950s. More than 115,000 cases and 3,000 deaths were reported from 1990 to 1997, and, in contrast to the situation in the prevaccine era, most of the cases and deaths occurred among adults. Contributing factors included the accumulation of susceptible individuals among both adults and children and probably the introduction of new strains of C. diphtheriae. Vaccine quality, vaccine supply, or access to vaccine providers did not significantly contribute to the epidemic. Mass vaccination of adults and improved childhood immunization controlled the epidemic. High levels of population immunity, especially among children, will be needed to prevent and control similar outbreaks in the future.

Adolescent↗

PubMed1957

The assay of diphtheria toxin.

A precise assay of diphtheria toxin is described, based on the linear relationship between the diameter of the skin reaction to, and logarithm of the dose of, toxin. It eliminates the need for preliminary titrations, is economical, provides information about the slope of the log-dose response lines and, therefore, of the validity of the assay, and yields limits of error of potency from the internal evidence of the assay.A study has been made of the effects of avidity, combining power, toxicity and buffering on the assay of diphtheria toxins against the International Standards for both Diphtheria Antitoxin and Schick-Test Toxin.All the toxins assayed against the standard toxin, whatever their other properties might be, gave log-dose response lines of similar slope provided that they were diluted in buffered physiological saline. The assays were therefore valid.These experiments were repeated concurrently in non-immune and in actively immunized guinea-pigs, and comparable figures for potency obtained in both groups. The result was not significantly affected by the avidity or combining power of the toxin.However, non-avid toxins gave low values in Schick units when assayed, by the Römer & Sames technique, in terms of the International Standard for Diphtheria Antitoxin. The problem of the ultimate standard and the implications of these findings are discussed.

Biological Assay↗

PubMed1988

Intracellular localization and degradation of diphtheria toxin.

The internalization of surface-bound diphtheria toxin (DT) in BS-C-1 cells correlated with its appearance in intracellular endosomal vesicles; essentially no toxin appeared within secondary lysosomal vesicles. In contrast, internalized epidermal growth factor (EGF) was localized within both endosomal and lysosomal vesicles. Upon preincubation of cells with leupeptin, a lysosomal protease inhibitor, a threefold increase in the accumulation of EGF into lysosomes was observed. Under identical conditions, essentially all of the diphtheria toxin remained within endosomes (less than 2% of the intracellular diphtheria toxin accumulated in the lysosomal fraction), indicating that the inability to detect diphtheria toxin in lysosomes was not due to its rapid turnover within this vesicle. Following internalization of EGF or DT, up to 40% of the ligand appeared in the medium as TCA-soluble radioactivity. EGF degradation was partially leupeptin-sensitive and markedly NH4Cl-sensitive, indicating lysosomal degradation. In contrast, DT A-fragment degradation was resistant to these inhibitors, while B-fragment showed only partial sensitivity. These data suggest that the bulk of endocytosed diphtheria toxin is localized within endosomes and degraded by a pathway essentially independent of lysosomes.

Animals↗

PubMed1984

Anion requirement and effect of anion transport inhibitors on the response of vero cells to diphtheria toxin and modeccin.

The anion requirement for toxic action of diphtheria toxin and modeccin was studied. In Cl- -free Hepes buffer made isotonic with mannitol, cells were insensitive to diphtheria toxin and modeccin. Just 2 mM NaCl was sufficient to obtain full toxic activity of modeccin, whereas 140 mM NaCl was required for maximal intoxication with diphtheria toxin. Br- could substitute for Cl-. NO3-,l-, and ClO3- were less efficient than Cl-, whereas SO42- and SCN- were unable to replace Cl- . Cl- deprivation both reduced the ability of cells to bind diphtheria toxin and prevented bound toxin from intoxicating the cells. The binding of modeccin was not reduced. SITS (4-acetamide-4'-isothiocyano-stilbene-2,2'-disulfonic acid), an inhibitor of Cl- entry, protected against diphtheria toxin and modeccin, indicating that Cl- transport is required for intoxication.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗

PubMed1985

Effect of potassium depletion of cells on their sensitivity to diphtheria toxin and pseudomonas toxin.

When Vero cells were depleted of potassium, the cells were protected against diphtheria toxin. Potassium depletion of Vero cells strongly reduced the binding of the toxin to cell surface receptors. Likewise, potassium depleted L-cells were protected against pseudomonas toxin. Diphtheria toxin binding was completely restored upon addition of potassium to the cells. This restoration was not prevented by inhibition of protein synthesis by cycloheximide. When cells were depleted of potassium in the presence of metabolic inhibitors, and then treated with diphtheria toxin, protein synthesis was reduced to the same extent as in cells with normal intracellular level of potassium. The results indicate that potassium depletion of Vero cells reduces the ability of the cells to bind diphtheria toxin by an ATP requiring process, and that binding, endocytosis and transfer of diphtheria fragment A across the membrane may occur at low intracellular levels of potassium.

ADP Ribose Transferases↗

PubMed2006

Mapping and comprehensive analysis of the extracellular and cell surface proteome of the human pathogen Corynebacterium diphtheriae.

Secreted proteins of the human pathogen Corynebacterium diphtheriae might be involved in important pathogen-host cell interactions. Here, we present the first systematic reference map of the extracellular and cell surface proteome fractions of the type strain C. diphtheriae C7s(-)tox-. The analysis window of 2-DE covered the pI range from 3 to 10 along with a MW range from 8 to 150 kDa. Computational analysis of the 2-D gels detected almost 150 protein spots in the extracellular proteome fraction and about 80 protein spots of the cell surface proteome. MALDI-TOF-MS and PMF with trypsin unambiguously identified 107 extracellular protein spots and 53 protein spots of the cell surface, representing in total 85 different proteins of C. diphtheriae C7s(-)tox-. Several of the identified proteins are encoded by pathogenicity islands and might represent virulence factors of C. diphtheriae. Additionally, four solute-binding proteins (HmuT, Irp6A, CiuA, and FrgD) of different iron ABC transporters were identified, with the hitherto uncharacterized FrgD protein being the most abundant one of the cell surface proteome of C. diphtheriae C7s(-)tox-.

Amino Acid Sequence↗

PubMedDate not supplied

Immune status against diphtheria among immigrants from the former USSR who arrived in Israel during 1990-1991.

Large outbreaks of diphtheria occurred recently in the former USSR. Between 1989 and 1994, a total of about 600,000 Soviet immigrants arrived in Israel. The immune status against diphtheria in a sample of 992 men aged 17-49 and 195 women aged 17-19, who arrived in Israel during 1990-91, was studied in order to evaluate the need for vaccination. Participants completed a self-administered questionnaire and diphtheria antitoxin antibody levels were measured by means of ELISA. At age 17-19, the prevalence of antitoxin antibody levels below the protective level of 0.01 IU/ml was 4.8% in the men and 2.1% in the women. Among the men, the percentage lacking protection declined from 4.8% at age 17-19 years to 1.6% at age 20-24, and increased to 18.2% at age 35-49. In the oldest group, the prevalence of those lacking protection was considerably higher than for the general Israeli population. In the multivariate analysis, age, mother's education and republic of origin were significantly associated with the absence of protection. Immigrants from the former USSR appear to be more susceptible to diphtheria, thus increasing the possibility of clinical disease, and it is recommended that they receive booster doses of diphtheria toxoid.

Adolescent↗

PubMed1999

Cell surface hydrophobicity of sucrose fermenting and nonfermenting Corynebacterium diphtheriae strains evaluated by different methods.

Corynebacterium diphtheriae strains expressed variation in hydrophobic characteristics dependent on the method used. Results of single assays are not a reliable representation of C. diphtheriae hydrophobicity. All 12 strains adhered to polystyrene surfaces; three showed spontaneous aggregation (SA) in Trypticase Soy Broth (TSB) medium, and eight exhibited autoagglutination in phosphate-buffered saline (PBS; AA-positive). The salt aggregation test (SAT) values </=0.002 or >/=1.6 represented breakpoints for groups of strains with differing hydrophobicity. C. diphtheriae strains showed affinity towards n-hexadecane. Percentages of adhesion varied from 31% to 63% and were not directly related to morphological n-hexadecane adhesion patterns. Diffuse and localized adhesion patterns were noted predominantly among sucrose-positive and sucrose-negative strains, respectively. Strains of the sucrose-negative biotype expressed a higher degree of hydrophobicity. The choice of the growth medium influenced the hydrophobicity, not the hemagglutinating activity (HA) of C. diphtheriae. Heating bacterial suspensions at 121 degrees C decreased both HA and hydrophobicity of three strains. However, hydrophobins and hemagglutinins were trypsin and detergent resistant. The treatment of microorganisms with Clostridium perfringens neuraminidase increased the hydrophobicity but not the HA titers of strains tested. Hemagglutinins were partially responsible for hydrophobicity. Hydrophilic AA-negative strains adhered strongly to glass but expressed weak HA. Sialylglycoconjugates functioned as hydrophilins on C. diphtheriae surfaces.

Agglutination↗

PubMed2005

Novel potentiometric immunosensor for determination of diphtheria antigen based on compound nanoparticles and bilayer two-dimensional sol-gel as matrices.

A novel method for fabrication of a diphtheria potentiometric immunosensor has been developed by means of self-assembling compound nanoparticles to a thiol-containing sol-gel network. A cleaned gold electrode was first immersed in a 3-mercaptopropyltrimethoxysilane (MPS) sol-gel solution to assemble a silica sol-gel monolayer. The silane entities were then polymerized into a two-dimensional sol-gel network (2D network) by dipping into aqueous NaOH. The second silane layer was formed by re-immersion in the MPS sol-gel solution overnight. The compound nanoparticles (nanocompounds) containing gold nanoparticles and silver nanoparticles were then chemisorbed on to the thiol groups of the second silane layer. Finally, diphtheria antibody (anti-Diph) was adsorbed on to the surface of the compound nanoparticles. The modified process was characterized by cyclic voltammetry (CV). Detection is based on the change in the potentiometric response before and after the antigen-antibody reaction. A direct potentiometric response to diphtheria antigen (Diph) was obtained from the immobilized diphtheria antibody. The potentiometric response of the resulting immunosensor was rapid and the linear range was from 22 to 800 ng mL-1 with the linear regression equation DeltaE=-79.5+69.4 log [Diph] and a detection limit of 3.7 ng mL-1 (at 3delta). Up to 19 successive assay cycles with retention of sensitivity were achieved for probes regenerated with 0.2 mol L-1 glycine-hydrochloric acid (Gly-HCl) buffer solution. Moreover, analytical results from several serum samples obtained using the developed technique were in satisfactory agreement with those given by the ELISA method, implying a promising alternative approach for detecting diphtheria antigen in clinical diagnosis.

Antibodies, Bacterial↗