Phase-shift markers in the genus Bordetella: loss of cytochrome d-629 in phase IV variants.

The respiratory electron transport chain of Bordetella pertussis was examined in whole cell suspensions using difference spectra obtained at room temperature. Phase I (virulent) strains were found to possess cytochromes a-603, b-560, c-550, d-629 and cytochrome o. Cytochrome c-553, previously reported (Sutherland, 1963) was not detected and was assumed to be masked by the alpha-peaks for c-550 and b-560. Phase IV (avirulent) strains and C-mode cells (phase I strains grown in the presence of 20 mM MgSO4) were deficient in cytochrome d-629 and appeared to have higher levels of cytochromes a-603, b-560, c-550 and cytochrome o. Preliminary data indicate that B. parapertussis and B. bronchiseptica have electron transport chains similar to that of B. pertussis.