Mixing of nasopharyngeal and oropharyngeal samples to identify potential respiratory pathogens in adults

A mixed culture of oropharyngeal swabs, nasopharyngeal swabs and nasopharyngeal washings, taken from 400 patients, was compared to separate cultures of the same samples. The mixed culture identified Streptococcus pneumoniae in 37 of 40 (93%) patients with positive samples, Hemophilus influenzae in 28 of 29 (97%), and Moraxella catarrhalis in 94 of 94 (100%). These sensitivity rates clearly justify the use of mixed cultures instead of separate cultures for clinical and epidemiological purposes. The reduction in costs stemming from the use of mixed cultures may have a decisive influence when considering this test for extensive clinical and epidemiological purposes.