MORAXELLA (BRANHAMELLA) CATARRHALIS ADHERENCE TO HUMAN BRONCHIAL AND OROPHARYNGEAL CELLS - THE ROLE OF ADHERENCE IN LOWER RESPIRATORY-TRACTINFECTIONS

To study the role of Moraxella (subgenus Branhamella) catarrhalis (B. catarrhalis) adherence to airway cells in lower respiratory tract infe ctions, the in vitro attachments of B. catarrhalis to upper airway (or opharyngeal) and lower airway (bronchial) epithelial cells were compar ed, The adherence of 4 strains (1 nonfimbriated and 3 fimbriated) of B . catarrhalis to respiratory tract epithelial cells collected from 11 patients with chronic pulmonary disease (CPD) and 11 healthy individua ls was evaluated, Both the fimbriated and nonfimbriated strains showed increased attachment to oropharyngeal cells in the CPD patients (mean +/- SEM; 25.0 /- +3.2/cell; P < 0.01) when compared to the control su bjects (12.1 +/- 1.1/cell). On the average, the attachment to bronchia l cells was 6.1 to 13.6 times greater per surface area (bacteria/mu m( 2)) than the attachment to oropharyngeal cells, The fimbriated strains tended to adhere in higher numbers to bronchial cells (19.0 +/- 1.8/c ell) than the nonfimbriated strain (8.7 +/- 1.2/cell), although there was no difference between the CPD and control groups, In conclusion, t he attachment of B. catarrhalis to oropharyngeal cells may be an enhan cing factor for colonization in the upper respiratory tract in patient s with CPI), and elevated adherence of the bacteria to bronchial cells may suggest pathogenic importance when mucociliary function is impair ed.