Oropharyngeal flora in asthma and in chronic obstructive pulmonary disease. Indigenous oropharyngeal microorganisms in outpatients with asthma or chronic obstructive pulmonary disease

In vitro and in vivo studies have shown that various strains of ''viridans streptococci'' (nongroupable alpha-hemolytic streptococci) inhabiting the oropharynx suppress the growth of gram-positive and gram-negative microorganisms. We conducted an inventory of the oropharyngeal flora from ambulatory asthma and chronic obstructive pulmonary disease (COPD) patients and a control group to examine the interaction between viridans streptococci and potential pathogens in vivo. In addition, the difference in colonization patterns of these bacteria was studied. Oral washings from 195 patients, 48 asthma (24.6%), 147 COPD (75.4%), and 157 control subjects were examined microbiologically on two occasions with a 2-wk interval, resulting in a total of 384 and 295 oral washings, respectively. All patients were ina stable phase of disease throughout the study. The distribution of low (less than or equal to 10(4)/ml) or high (greater than or equal to 10(5)/ml) concentrations of viridans streptococci did not differ substantially between asthma or COPD patients and control subjects. Potentially pathogenic microorganisms found in a low (less than or equal to 10(4)/ml) or high (greater than or equal to 10(5)/ml) concentration were equally distributed between the two groups. Staphylococcus aureus and beta-hemolytic streptococci were found significantly less often in the asthma and COPD group (p