Please use this identifier to cite or link to this item:http://hdl.handle.net/20.500.12105/8271
New mutations and horizontal transfer of rpoB among rifampin-resistant Streptococcus pneumoniae from four Spanish hospitals
Antimicrob Agents Chemother. 2005 Jun;49(6):2237-45.
A total of 103 (0.7%) of 14,236 Streptococcus pneumoniae isolates collected in four Spanish hospitals from 1989 to 2003 were resistant to rifampin (MICs, 4 to 512 microg/ml). Only sixty-one (59.2%) of these isolates were available for molecular characterization. Resistance was mostly related to human immunodeficiency virus (HIV) infection in adult patients and to conjunctivitis in children. Thirty-six different pulsed-field gel electrophoresis patterns were identified among resistant isolates, five of which were related to international clones (Spain23F-1, Spain6B-2, Spain9V-3, Spain14-5, and clone C of serotype 19F), and accounted for 49.2% of resistant isolates. Single sense mutations at cluster N or I of the rpoB gene were found in 39 isolates, while double mutations, either at cluster I, at clusters I and II, or at clusters N and III, were found in 14 isolates. The involvement of the mutations in rifampin resistance was confirmed by genetic transformation. Single mutations at clusters N and I conferred MICs of 2 microg/ml and 4 to 32 microg/ml, respectively. Eight isolates showed high degrees of nucleotide sequence variations (2.3 to 10.8%) in rpoB, suggesting a recombinational origin for these isolates, for which viridans group streptococci are their potential gene donors. Although the majority of rifampin-resistant isolates were isolated from individual patients without temporal or geographical relationships, the clonal dissemination of rifampin-resistant isolates was observed among 12 HIV-infected patients in the two hospitals with higher rates of resistance.
Amino Acid Sequence | Anti-Bacterial Agents | Base Sequence | DNA-Directed RNA Polymerases | Drug Resistance, Bacterial | Hospitals | Humans | Microbial Sensitivity Tests | Molecular Sequence Data | Phylogeny | Pneumococcal Infections | Rifampin | Sequence Analysis, DNA | Spain | Streptococcus pneumoniae | Gene Transfer, Horizontal | Mutation
Files in this item
- FIG 1_NewMutationsAndHorizonta ...
- FIG 2_NewMutationsAndHorizonta ...
- FIG 3_NewMutationsAndHorizonta ...
- FIG 4_NewMutationsAndHorizonta ...