Culture and fluorescent-antibody methods in diagnosis of whooping cough. J. Bacteriol. 86: 449-451. 1963.-Nasopharyngeal swabs from 517 suspected whooping-cough patients were examined by culture and by fluorescent-antibody (FA) staining procedures applied to direct slide preparations. A total of 138 were positive by both methods, 25 by culture only, and 25 by FA only. The FA technique was also used in the identification of young cultures. It was shown that a positive culture report could be speeded up by about 1 day by this method. Without FA, onehalf the positive culture reports were made in 3 days; with FA, 75% were reported in a similar period.

To determine the Bordetella pertussis serotypes currently causing whooping cough in the United States, recently isolated cultures from different geographic areas were studied. Specific adsorbed antisera were prepared in our laboratory and used in both tube and slide agglutination tests. Among the 177 cultures isolated during 1966 and 1967 in seven states and one Canadian province, the predominant serotype was 1.3 (or 1.3.6), represented by 85 % of the cultures. Fifteen cultures were serotype 1.2.3.4.6. The 376 cultures isolated in the Grand Rapids area during the last 30 years showed a changing pattern from serotype 1.2.3 during the early years to the currently prevailing 1.3 (or 1.3.6). During the 2-year study period, seven cultures of B. parapertussis were isolated in Michigan, and seven were received from other states. One culture of B. bronchiseptica, recovered from a child in Boston, was sent to us.

Preston's description of Bordetella pertussis 353-Z as a culture possessing only factor 1 was confirmed by agglutination and agglutinin-adsorption tests. The LD50 values of this culture for mice inoculated by the intracerebral route were approximately the same as that of B. pertussis 18-323, the challenge culture in mouse potency tests of pertussis vaccine. In mouse protection tests, vaccine prepared with the factor 1 culture protected as well against challenge with B. pertussis 18-323, which has a broad antigenic pattern, as did vaccines made with cultures possessing factors 2, 3, 4, and 5 in addition to factor 1. When two groups of similarly immunized mice were challenged with 353-Z and 18-323, respectively, much lower ED50 values were obtained with the animals challenged with 353-Z. This was true whether a factor 1 vaccine or a vaccine with factors 1, 2, 3, 4, and 5 was tested.

In a passive protection procedure in which the ED50 values of Bordetellc/ pertuessis antisera were determined, groups of mice were given graded intraperitoneal doses of serum, followed the next day by intracerebral challenge with 100,000 organisms. Antiserum produced with B. pertussis culture 5373, serotype 1 3, protected mice against challenge with culture 18-323, serotype 1 2. 3, as effectively as did an antiserum produced with a serotype 1 2.3 culture. When two groups of mice similarly treated with pertussis immune serum were challenged with culture 353Z (serotype 1) and 18-323, respectively, much lower ED50 values were obtained with the animals challenged with 353Z. Passive protection tests with adsorbed antiserum gave equivocal results, suggesting that some of the adsorbing antigen remained in the serum and interfered with the tests. There was no evidence that serotype is related to protection.

To determine the Bordetella pertussis serotypes currently causing whooping cough in the United States, recently isolated cultures from different geographic areas were studied. Specific adsorbed antisera were prepared in our laboratory and used in both tube and slide agglutination tests. Among the 177 cultures isolated during 1966 and 1967 in seven states and one Canadian province, the predominant serotype was 1.3 (or 1.3.6), represented by 85% of the cultures. Fifteen cultures were serotype 1.2.3.4.6. The 376 cultures isolated in the Grand Rapids area during the last 30 years showed a changing pattern from serotype 1.2.3 during the early years to the currently prevailing 1.3 (or 1.3.6). During the 2-year study period, seven cultures of B. parapertussis were isolated in Michigan, and seven were received from other states. One culture of B. bronchiseptica , recovered from a child in Boston, was sent to us.