Antimycobacterial Activity of Veterinary Antibiotics (Apramycin and Framycetin) against Mycobacterium abscessus: Implication for Patients with Cystic Fibrosis

Background: Antimicrobial resistance has rendered certain species of Mycobacterium difficult to treat clinically, particularly the nontuberculous Mycobacterium and Mycobacterium abscessus. While veterinary medicine and human medicine share many classes of antibiotics, there are several antibiotics which are uniquely licensed to veterinary medicine but not human medicine. It was, therefore, the aim of this study to examine the action of eight veterinary antibiotics to a population of multi-and pan-resistant M. abscessus, isolated from the sputum of patients with cystic fibrosis (CF). Methods: Antibiotic susceptibility studies were performed on human clinical isolates of M. abscessus (n = 16), including 11 smooth isolates, 4 rough isolates, and 1 reference isolate (NCTC 13031), against the following 7 veterinary antibiotics (antibiotic class): apramycin (aminoglycoside), cefovecin (cephalosporin), ceftiofur (cephalosporin), framycetin (aminoglycoside), lincomycin (lincosamide), pirlimycin (lincosamide), and spectinomycin (aminocyclitol). Results: M. abscessus isolates were sensitive (100%) to apramycin and framycetin but resistant (100%) to cefovecin, ceftiofur, lincomycin, pirlimycin, and spectinomycin. Conclusion: This study identified that the veterinary aminoglycosides, apramycin, and framycetin, have in vitro activity against multi-resistant clinical isolates of M. abscessus. Further studies should now compare the activity of these antibiotics against amikacin and the human aminoglycoside, advocated in the treatment of disease in CF patients, to determine if these novel antibiotics have a future role for the development in human medicine with such chronic disease patients.