Effects of clarithromycin at sub-minimum inhibitory concentrations on early ermB gene expression, metabolic activity and growth of an erm(B)-expressing macrolide-resistant strain of Streptococcus pneumoniae
dc.contributor.author | Cockeran, Riana | |
dc.contributor.author | Steel, Helen Carolyn | |
dc.contributor.author | Wolter, Nicole | |
dc.contributor.author | De Gouveia, L. | |
dc.contributor.author | Von Gottberg, Anne | |
dc.contributor.author | Klugman, Keith P. | |
dc.contributor.author | Leanord, A.T. | |
dc.contributor.author | Inverarity, D.J. | |
dc.contributor.author | Mitchell, Timothy J. | |
dc.contributor.author | Feldman, Charles | |
dc.contributor.author | Anderson, Ronald | |
dc.contributor.email | riana.cockeran@up.ac.za | en_US |
dc.date.accessioned | 2012-06-19T07:14:09Z | |
dc.date.available | 2012-06-19T07:14:09Z | |
dc.date.issued | 2012-02 | |
dc.description.abstract | AIM: To investigate the effects of exposure of a macrolide-resistant [erm(B)-expressing] strain of Streptococcus pneumo- niae (strain 2507) to clarithromycin (0.5 and 5 mg/L) added at the outset and 6 hours after initiation of culture on early gene expression, energy metabolism, and growth. METHODS: Bacterial growth was determined by turbidometric and colony counting procedures, energy metabolism by measurement of ATP, while analysis of gene expression was per- formed using reverse transcription-PCR and sequencing. RESULTS: Addition of clarithromycin, at either concentration, at the outset of culture, caused transient suppression of growth of 10 - 12 hours duration, while delayed addition of antibi-otic (during the logarithmic phase) resulted in an abrupt halt in growth followed by recovery. These inhibitory effects of clarithromycin on bacterial growth were associated with up-regulation of expression of erm(B), decreased ATP and protein synthesis, and were unaffected by inclusion of either catalase (500 and 1000 kunits/L), or compe- tence-stimulating peptide (CSP-1, 0.5 mg/L). The inhibitory effects could, however, be overcome by pre-exposure of the bacteria to the antibiotic. Moreover, clarithromycin appeared to potentiate the antimicrobial actions of ceftriaxone, at sub-MIC concentrations, for strain 2507. CONCLUSIONS: Unlike several other common bacterial pathogens, the full expression of erm(B)-mediated macrolide resistance by the pneumococcus has a slow onset, which is associated with transient susceptibility to macrolides and inhibition of growth. | en_US |
dc.description.sponsorship | CF is supported by the National Research Foundation of South Africa. | en_US |
dc.description.uri | http://www.SciRP.org/journal/ojrd | en_US |
dc.identifier.citation | Cockeran, R, Steel, HC, Wolter, N, De Gouveia, L, Von Gottberg, A, Klugman, KP, Leanord, AT, Inverarity, DJ, Mitchell, TJ, Feldman, C & Anderson, R 2012, 'Effects of clarithromycin at sub-minimum inhibitory concentrations on early ermB gene expression, metabolic activity and growth of an erm(B)-expressing macrolide-resistant strain of Streptococcus pneumoniae', Open Journal of Respiratory Diseases, vol. 2, no. 1, pp. 1-8. | en_US |
dc.identifier.issn | 2163-940X (print) | |
dc.identifier.issn | 2163-9418 (online) | |
dc.identifier.other | 10.4236/ojrd.2012.21001 | |
dc.identifier.uri | http://hdl.handle.net/2263/19209 | |
dc.language.iso | en | en_US |
dc.publisher | Scientific Research Publishing Inc | en_US |
dc.rights | Copyright © 2012 SciRes. | en_US |
dc.subject | Clarithromycin | en_US |
dc.subject | Pneumococcus | en_US |
dc.subject | Macrolide-resistance | en_US |
dc.subject.lcsh | Pneumonia -- Treatment | en |
dc.title | Effects of clarithromycin at sub-minimum inhibitory concentrations on early ermB gene expression, metabolic activity and growth of an erm(B)-expressing macrolide-resistant strain of Streptococcus pneumoniae | en_US |
dc.type | Article | en_US |