A colorimetric amplification-based method for identification of Moraxella catarrhalis, a human respiratory tract pathogen

<i>Moraxella catarrhalis</i> is a significant pathogen associated with both upper and lower respiratory tract infections. This study aims to identify <i>M. catarrhalis</i> using the <i>ompCD</i> gene, which encodes a major outer membrane protein. Spectrophotometry was used to evaluate the accuracy of the colorimetric method by measuring the A450/A570. The colorimetric measurements and PCR method specificity were assessed utilizing twenty bacterial samples. The results of <i>M. catarrhalis</i> detection confirmed the presence of a specific band at 273 base pairs and a light red color, with an A450/A570 ratio of 1.5. However, 100% specificity was observed in negative samples with an A450/A570 ratio of 1.15 or less, lacking an amplicon band and showing a deep red color. Furthermore, the selectivity of the techniques was confirmed. The methods revealed a detection limit of 0.05 <i>n</i>g/<i>μ</i>L. The colorimetric PCR approach is a suitable point-of-care test for rapidly and accurately identifying <i>M. catarrhalis</i>.