Phenotypic resistance in mycobacteria: is it because I am old or fat that I resist you?

Hammond, R. J.H., Baron, V. O., Oravcova, K. , Lipworth, S. and Gillespie, S. H. (2015) Phenotypic resistance in mycobacteria: is it because I am old or fat that I resist you? Journal of Antimicrobial Chemotherapy, 70(10), pp. 2823-2827. (doi: 10.1093/jac/dkv178) (PMID:26163401)

Abstract

Objectives: We aimed to explore the phenomenon of phenotypic resistance to antimycobacterial antibiotics and to determine whether this was associated with cell age or the presence of lipid bodies. Methods: The accumulation of lipid-body-positive [lipid-rich (LR)] cells was followed using cell staining and flow cytometry. LR cells of Mycobacterium smegmatis, Mycobacterium marinum, Mycobacterium fortuitum and Mycobacterium bovis (BCG) were separated from non-lipid-body-containing [lipid-poor (LP)] cells and their MBCs determined. We also compared the MBCs for LR and LP cells from ‘old’ and ‘young’ cultures. Results: The LR cells of all species were more resistant to antibiotics than LP cells. For BCG, the susceptibility ratios were as follows: rifampicin, 5×; isoniazid, 16.7×; ethambutol, 5×; and ciprofloxacin, 5×. Phenotypic resistance was found in LR cells irrespective of cell age. Conclusions: We have shown that phenotypic antibiotic resistance is associated with the presence of lipid bodies irrespective of cell age. These data have important implications for our understanding of relapse in mycobacterial infections.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Oravcova, Dr Katarina
• Authors: Hammond, R. J.H., Baron, V. O., Oravcova, K., Lipworth, S., and Gillespie, S. H.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Journal of Antimicrobial Chemotherapy
• Publisher: Oxford University Press
• ISSN: 0305-7453
• ISSN (Online): 1460-2091