ELECTRON-MICROSCOPIC OBSERVATION OF BRANHAMELLA-CATARRHALIS

The hemagglutination (HA) test was done on 85 strains of Bronhamella catarrhalis, isolated from sputum of patiemts with respiratory infections; 53% were HA positive strains. Three HA positive and three HA negative strains were selected and were observed under the electron microscope. The bacterial cell wall appeared to be lobulated and its total thickness was about 38 nm. The nuclear region consisted of whorls or fibrils and dense bodies. Five strains were fimbriated and one strain was nonfimbriated. The size of rimbriae was about 68 nm in length and 4.5 nm in width. The finbrae of Branhamella catarhalis were densely arranged and peritrichous in distribution. There was no change of fimbriation between broth and agar cultures.