Bordetella pertussis serotypes in the United States

Analysis of Bordetella pertussis populations in European countries with different vaccination policies

Despite the widespread use of pertussis vaccines during the last decades, pertussis has remained an endemic disease with frequent epidemic outbreaks. Currently two types of vaccines are used: whole-cell vaccines (WCVs) and recently developed acellular vaccines (ACVs). The long-term aim of our studies is to assess the effect of different vaccination policies on the population structure of Bordetella pertussis and ultimately on the disease burden in Europe. In the present study, a total of 102 B. pertussis isolates from the period 1998 to 2001 from five European countries (Finland, Sweden, Germany, The Netherlands, and France) were characterized. The isolates were analyzed by typing based on variable number of tandem repeats (VNTR); by sequencing of polymorphic genes encoding the surface proteins pertussis toxin S1 and S3 subunits (ptxA and ptxC), pertactin (prn), and tracheal colonization factor (tcfA); and by fimbrial serotyping. The results reveal a relationship between geographic location and VNTR types, the frequency of the ptxC alleles, and serotypes. We have not observed a relationship between the strain characteristics we studied and vaccination programs. Our results provide a baseline which can be used to reveal changes in the B. pertussis population in Europe in the coming years.

Human infections associated with Bordetella bronchiseptica

This study examines the potential of Bordetella bronchiseptica to act as a human pathogen. After encountering two patients from whom B. bronchiseptica was isolated, we searched the literature and found 23 reports in which a human infection was reported in association with B. bronchiseptica. As a basis for evaluating these cases, we summarize the literature about the current microbiological status of B. bronchiseptica, the pathology and pathogenic mechanisms associated with the microorganism, and the likelihood of it acting as a commensal or colonizer. From this review we conclude that B. bronchiseptica has been rarely isolated from humans despite their considerable exposure to animal sources. Evidence suggests that B. bronchiseptica may be rarely encountered as a commensal or colonizer of the respiratory tract of humans and rarely in association with infection. When found as a probable pathogen, most infections have been respiratory tract in origin and have occurred in severely compromised hosts.

Identification of a 69-kilodalton nonfimbrial protein as an agglutinogen of Bordetella pertussis

Cells of Bordetella pertussis BP353, a nonfimbriated Eldering serotype 1.3 strain, were used as an immunogen to produce three monoclonal antibodies, BPE3, BPD8, and BPE8, that agglutinated the immunizing cells, as well as certain other nonfimbriated and fimbriated serotype 3-containing B. pertussis strains. The antibodies did not agglutinate serotype 1 or nontypable B. pertussis cells. These monoclonal antibodies specifically detected a 69-kilodalton (kDa) band on Western blots (immunoblots) containing whole B. pertussis cell lysates of Eldering agglutinogen serotypes 1.3, 1.3.6, 1.2.3.4, and 1.2.3.4.6. This 69-kDa antigen was released from the bacteria by cell incubation for 60 min at 60 degrees C, and it was purified by affinity chromatography with a BPE3-agarose affinity matrix. Purified material was used to produce a polyclonal antiserum that agglutinated all nonfimbriated and fimbriated B. pertussis cells containing serotype 3 agglutinogen. Immunogold electron microscopy and indirect immunofluorescence studies demonstrated that it is an outer membrane constituent but nonfimbrial in appearance. BPE3 did not detect purified fimbriae on Western blots, and antibodies to these fimbriae did not bind to the 69-kDa component. Although B. bronchiseptica and B. parapertussis cells were not agglutinated by the monoclonal antibodies, antigenically similar proteins were detected in extracts of the bacteria. These results identify the 69-kDa protein as a nonfimbrial agglutinogen present on all virulent strains of B. pertussis. The monoclonal antibodies described here should be useful for further studies on the structure and function of this protein.

Pertussis: the disease and new diagnostic methods

Bordetella pertussis, the causative agent of whooping cough, produces an acute and chronic respiratory infection in infants and young children. B. pertussis is still a major health problem of young children throughout the world even though effective immunization against whooping cough is available. While predominantly a childhood disease, it has been reported also to be a cause of persistent cough in adults. This review discusses the numerous bacterial virulence factors that may play roles in the pathogenesis of pertussis and in immunity to infection. The present problems with pertussis diagnosis, recent advances, and future prospects for new and improved rapid diagnostics tests also are explored.

Purification and characterization of serotype 6 fimbriae from Bordetella pertussis and comparison of their properties with serotype 2 fimbriae

Fimbriae were removed from Bordetella pertussis (serotype 1.3.6) by mechanical shearing and purified by precipitation with ammonium sulfate, pH-dependent precipitation at pH 7.4, followed by two successive extractions of the precipitated fimbriae with 4 M urea. By electron microscopy, the precipitated fimbriae appeared as aggregated bundles of long, relatively straight filaments which were disaggregated to individual flexuous filaments at pH 10.5. These purified fimbriae were identified as serotype 6 agglutinogens, since antibody to the purified fimbriae agglutinated B. pertussis strains serotyped as 1.3.6, 1.2.3.6, or 1.2.3.4.6 but did not agglutinate strains of serotype 1.2.3.4, 1.2.3, or 1.3. In contrast, antibody to serotype 2 fimbriae only agglutinated B. pertussis strains containing serotype 2 agglutinogen. Purified type 6 and 2 fimbriae were found to be weakly cross-reactive by enzyme-linked immunosorbent assay, using polyclonal antibody to each type of fimbria. In an immunoblot assay, polyclonal antibodies to a 22,000-dalton subunit of fimbriae from B. bronchiseptica reacted strongly with the type 2 fimbrial subunit of B. pertussis, but only weakly with the type 6 subunit. When subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the protein subunit of the type 6 fimbriae migrated with a molecular weight of 21,500, whereas the type 2 fimbrial subunit had a molecular weight of 22,000. The two types of subunits had similar amino acid compositions and showed amino-terminal sequence homology in 15 of 21 amino acids. The amino-terminal amino acid sequences of the B. pertussis fimbriae were distinct from those reported for fimbriae from other gram-negative bacteria. Neither the type 6 nor the type 2 fimbriae caused hemagglutination when assayed with several types of erythrocytes.

Filamentous hemagglutinin has a major role in mediating adherence of Bordetella pertussis to human WiDr cells

[35S]methionine-labeled Bordetella pertussis adhered to monolayers of WiDr cells, an epitheliumlike cell line from a human intestinal carcinoma. Adherence was proportional to the density of the WiDr cells and to the concentration of B. pertussis in the assay. Adherence of virulent phase I strains Tohama phase I, 114, and BP338 was much greater than adherence of avirulent strains Tohama phase III and 423 phase IV. Mutants deficient in the production of the filamentous hemagglutinin (FHA) were hemagglutination negative and adhered to WiDr cells much less efficiently than the parent strains. Preincubation of B. pertussis cells with FHA increased their hemagglutination activity and adherence to WiDr cells. Goat antibody to FHA inhibited, in a dose-dependent manner, the adherence of strain Tohama I but not the adherence of FHA-deficient mutant Tohama 325. At similar protein concentrations, normal goat antibody, goat antibody to pertussis toxin, or the Fab fragments of goat antibody to serotype 2 fimbriae had no effect on adherence. Also, an FHA-positive strain without fimbriae showed high adherence, while a fimbriated FHA-deficient mutant adhered poorly. Our data indicate that FHA plays a major role in adherence of B. pertussis to human WiDr cells. Fimbriae do not appear to mediate attachment of B. pertussis to WiDr cells.

Purification and characterization of fimbriae isolated from Bordetella pertussis

Fimbriae were detached from Bordetella pertussis by mechanical shearing and purified by successive precipitations with ammonium sulfate, phosphate buffer (pH 6.0), and magnesium chloride. In each of these purification steps, the fimbriae aggregated into bundles as seen by electron microscopy. These aggregates could be disaggregated at pH 9.5. By electron microscopy, the purified fimbriae appeared as long filaments with a diameter of 5 nm. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified fimbriae showed a single protein subunit with a molecular weight of 22,000. The purified fimbriae did not have hemagglutinating activity when assayed with several types of erythrocytes, and they were antigenically, chemically, and structurally distinct from the filamentous hemagglutinin of B. pertussis. The purified fimbriae were also identified as serotype 2 agglutinogens, since antibody to the purified fimbriae agglutinated B. pertussis strains serotyped as 1.2.4, 1.2.3, or 1.2.3.6 but did not agglutinate those serotyped as 1.3.6.

Bordetella pertussis serotypes in Canada

A study was done to determine the major antigenic factors of Bordetella pertussis strains isolated throughout Canada and whether these isolates have the same antigenic structure as the bacilli in the currently used vaccines. Testing for the major pertussis antigens, factors 1, 2 and 3, was conducted with 440 freshly isolated strains of B. pertussis received from seven canadian provinces between August 1976 and February 1978 and six batches of pertussis vaccine or immunizing agents containing pertussis vaccine. With the aid of specific antisera prepared in rabbits, the antigenic factors were detected by a slide agglutination technique. Almost all (98.9%) of the pertussis strains examined were serotype 1,3. All six batches of pertussis vaccine or immunizing agents containing pertussis vaccine proved to be rich in each of the three main pertussis agglutinogens.

Pertussis outbreak in Austin and Travis County, Texas, 1975

An outbreak of bacteriologically proven pertussis occurred in Austin and Travis County, Texas, over a 7-month period in 1975. Eighty persons were cultured for pertussis in our laboratory. A total of 62% of specimens from 34 individuals with suspected pertussis was positive for Bordetella pertussis. Diagnosis of acute cases by both culture and fluorescent antibody was attempted, and the correlation of the methods is given. Analyses of cases by age, sex, immunization status, and antibiotic treatment prior to culture are included in this report. Two asymptomatic, culture-positive adults were found.

Prevalent serotypes of Bordetella pertussis in non-vaccinated communities

In many countries, the prevalent serotypes of Bordetella pertussis have changed from a mixture of types 1,2,3 and 1,2 (organisms possessing antigen 2) to a predominance of type 1,3. The timing of the change in different countries is shown to be related to the introduction of mass-vaccination with material rich in antigens 1 and 2 but weak in, or devoid of, antigen 3. In several parts of the world, there have been outbreaks of type 1,3 infection in fully vaccinated children. Non-vaccinated communities in various parts of the world still show the pattern of serotypes which existed elsewhere before mass-vaccination. In order to avoid the disappointments experienced in the past, it is essential that pertussis vaccine for use in previously non-vaccinated communities, like that for any other country, should be rich in each of the three antigens.

The serotypes of Bordetella pertussis isolated in Great Britain between 1941 and 1968 and a comparison with the serotypes observed in other countries over this period

Classification, by agglutinogens, of 634 isolates of Bordetella pertussis collected from 1971 to 1968 in Great Britain demonstrated that a change from a predominantly 1,2,0,4 serotype (75% of those examined during 1941-4) to a predominantly 1,0,3,0 serotype (73% of those examined during 1966-8) occurred sometime after 1953. Furthermore, evidence from the examination of isolates collected between 1941 and 1953 suggests that the change may have been gradual. Isolates of serotype 1,2,3,4 made up 20-30% of the total of our cross-country selection for the periods 1941-4, 1946-9, 1950-3 and 1966-8, but over shorter periods in individual areas the percentage varied from negligible to as high as half of those isolated. Results from other countries show a similar drift towards a 1,0,3 sertype but more often from a 1,2,3 than from 1,2,0 serotype. The value, in epidemiological studies, of extended information obtained by monospecific typing sera to all six, rather than only two or three agglutinogens, and confirmation of the results by agglutinin production is demonstrated: for instance not all 1,0,3 isolates were identical.