Nonselective media and previously described selective media were used to study the occurrence of Moraxella (Branhamella) catarrhalis in sputum samples of good and poor quality and in samples taken from different sites of the upper respiratory tracts of healthy subjects. It was found that in healthy adults the carrier rate was 5.4%, as opposed to 50.8% in children and 26.5% in people older than 60 years. M. catarrhalis was recovered significantly more often from sputum samples of good quality (5%) than from poor quality samples (0.5%), and when present, it was found mostly in the presence of high inocula. From these data gathered from healthy and diseased subjects, it is concluded that the presence of M. catarrhalis in the sputum of adults is rarely due to oronasopharyngeal contamination of the sputum. Similar findings reported by others are discussed, and the origins of the currently held concept that M. catarrhalis is a common commensal organism of the human upper respiratory tract are traced.

No abstract

The efficient and fast isolation of microorganisms from infected SF by the BACTEC system allows for rapid susceptibility testing and a more appropriate antibiotic treatment.

Branhamella catarrhalis from different parts of the world were serologically typed according to their lipopolysaccharide (LPS) antigenicity. For this purpose, an inhibition enzyme-linked immunosorbent assay was developed using the following reagents: antisera raised against whole bacterial suspensions for a panel of 16 serotype strains and LPS prepared from these strains by phenol extraction. Antisera were absorbed with whole bacterial suspensions of the B. catarrhalis strains to be tested. The residual activity of the sera against the homologous LPS was determined by means of an enzyme-linked immunosorbent assay, using microdilution plates coated with LPS. Strains which gave >90% reduction of activity were considered to carry the same LPS type as the serotype strain. It was shown that 93.4% of the strains tested carried one of three possible LPS types. LPS of B. catarrhalis are the rough type and have an apparent Mr of 5,500, as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

The results of our study seem to indicate a better sensitivity for the Respifinder. Analysis of patient samples is necessary to evaluate the clinical performance.