Mycobacterium avium (M. avium), a type of nontuberculous mycobacteria (NTM), poses a risk for pulmonary infections and disseminated infections in immunocompromised individuals. Conventional treatment consists of a 12-month regimen of the first-line antibiotics rifampicin and azithromycin. However, the treatment duration and low antibiotic tolerability present challenges in the treatment of M. avium infection. Furthermore, the emergence of multidrug-resistant mycobacterium strains prompts a need for novel treatments against M. avium infection. This study aims to test the efficacy of a novel antimicrobial peptide, cyclic [R4W4], alongside the first-line antibiotics azithromycin and rifampicin in reducing M. avium survival. Colony-forming unit (CFU) counts were assessed after treating M. avium cultures with varying concentrations of cyclic [R4W4] alone or in conjunction with azithromycin or rifampicin 3 h and 4 days post-treatment. M. avium growth was significantly reduced 4 days after cyclic [R4W4] single treatment. Additionally, cyclic [R4W4]–azithromycin and cyclic [R4W4]–rifampicin combination treatments at specific concentrations significantly reduced M. avium survival 3 h and 4 days post-treatment compared with single antibiotic treatment alone. These findings demonstrate cyclic [R4W4] as a potent treatment method against M. avium and provide insight into novel therapeutic approaches against mycobacterium infections.
nontuberculous mycobacteria, Mycobacterium avium, azithromycin, rifampicin, immunocompromised
Kelley M, Sasaninia K, Abnousian A, Badaoui A, Owens J, Beever A, Kachour N, Tiwari RK, Venketaraman V. Additive Effects of Cyclic Peptide [R4W4] When Added Alongside Azithromycin and Rifampicin Against Mycobacterium avium Infection. Pathogens. 2023; 12(8). doi: 10.3390/pathogens12081057.