Manuka honey in combination with azithromycin shows potential for improved activity against Mycobacterium abscessus

Abstract

Mycobacterium abscessus is an increasingly prevalent opportunistic pathogen causing both pulmonary and skin and soft tissue infections. It is of increasing concern for immunocompromised individuals, such as those with cystic fibrosis, due to its highly drug resistant nature and ability to evade the host immune system. Current treatments for M. abscessus pulmonary infections are largely ineffective and treatment outcomes are generally poor, thus we urgently require new treatments to combat these infections. Recently, it has been demonstrated that manuka honey is effective against M. abscessus and can improve the inhibitory effect of amikacin. Here, we explore the potential improvement of both azithromycin and tobramycin with the addition of manuka honey against M. abscessus complex. Improved growth inhibition was observed for azithromycin with manuka honey against all M. abscessus subspecies. Improved bactericidal activity was also observed. Importantly, the macrolide resistant M. abscessus subsp. bolletii showed improved inhibition and bactericidal activity was obtained in response to 0.117 g/mL manuka honey MGO40 with 16 µg/mL azithromycin. No improved activity was observed for tobramycin and manuka honey against any of the M. abscessus isolates tested. This demonstrates the potential for antibiotic enhancement by the addition of manuka honey, furthering the applications of therapeutic manuka honey.