A selective medium, chocolate agar with vancomycin, bacitracin, and clindamycin, was used to enhance the recovery of Haemophilus influenzae from adult patients. Cultures of the 634 respiratory specimens yielded 130 (20.5 percent) H. influenzae isolates, representing 93 patients. The serotype, biotype, and Beta-lactamase production of all isolates were determined. Of 103 distinct isolates, nine percent were serotypable and included serogroups a ,b ,d ,and e. Although biotypes I, II, III, V, and VI were represented, 81.5 percent of the isolates were in the II/III group. Twenty-six percent of the isolates were Beta-lactamase producers and, therefore, ampicillin resistant. The clinical characteristics of all patients were evaluated and used to categorize patients according to disease syndromes. Patients for whom Hj^ influenzae was the primary pathogen were categorized as having an acute exacerbation, febrile tracheobronchitis or pneumonia. Colonized patients and those with mixed pneumonia with other pathogens identified were the remaining categories. When evaluated by clinical categories, nonserotypable organisms were the most common, irrespective of disease. Biotypes II and III predominated in all patient groups, VLl and the average Beta-lactamase production of the three groups with clinically important disease with influenzae as the primary pathogen was 33 percent. It was determined that selective media was not needed for the recovery of H. influenzae in patients with clinically important disease. A Gram stain and chocolate agar plate were adequate when used by a skilled technologist. In general, selective media resulted in growth of H. influenzae in patients with no disease (i.e. colonized) when compared to chocolate agar only. However, selective media did prove beneficial when the patients had received antibiotics prior to culturing.
Master of Science in Nursing (MSN)
Harry L. Sherman
Norris, Mildred Ramsey, "Haemophilus Influenzae in Adults: an Analysis of Incidence, Serotype, Biotype, Beta-lactamase Production and Clinical Spectrum" (1985). MSN Research Projects. 216.