Background: Moraxella catarrhalis is the most common gram-negative bacteria pathogen that affects the human. The current study was carried out to investigate M. catarrhalis infection and how it modulates some biomarkers.
Methods: The samples were collected from 100 patients diagnosed with respiratory tract infections such as pneumonia, otitis media, and tonsillitis. Cultural characteristics were for the colonies cultured on blood and hot blood media. Microscopic method, biochemical tests, and Vitek 2 system was tested and they showed that ten isolates were M. catarrhalis.
Results: Out of 10 isolates, 8 isolates (80%) were β-lactamase-producing. The sensitivity of the isolates was deter-mined against seven antibiotics, and they showed multidrug resistance (MDR). All isolates showed 100% resistance to Ampicillin and Ceftazidime; however, the isolates showed less resistance to Meropenem and Imipenem. Enzyme-linked immunosorbent assay was used to determine the levels of Anti-DNA, IgM, IgG, IL-1β and hs-CRP in the patient serum. The infected serum with M. catarrhalis showed normal levels of Anti-DNA and IgM compared to control group, while the serum with high levels of IgG, IL-1β, and hs-CRP were recorded (p < 0.001).
Conclusions: The multi-antibiotic resistance of M. catarrhalis plays an important role in raising pro-inflammatory markers such as IgG, IL-1β, and hs-CRP levels, which may subsequently affect the respiratory tract.