2024-03-28T19:57:23Zhttp://repisalud.isciii.es/oai/requestoai:repisalud.isciii.es:20.500.12105/82712022-10-10T07:57:09Zcom_20.500.12105_15322com_20.500.12105_2051com_20.500.12105_2060com_20.500.12105_2052col_20.500.12105_16962col_20.500.12105_2061
00925njm 22002777a 4500
dc
Ferrandiz-Avellano, Maria-Jose
author
Ardanuy, Carmen
author
Liñares, Josefina
author
García-Arenzana, José María
author
Cercenado, Emilia
author
Fleites, Ana
author
de la Campa, Adela G
author
2005-06
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.
Antimicrob Agents Chemother. 2005 Jun;49(6):2237-45.
0066-4804
http://hdl.handle.net/20.500.12105/8271
15917517
10.1128/AAC.49.6.2237-2245.2005
Antimicrobial agents and chemotherapy
New mutations and horizontal transfer of rpoB among rifampin-resistant Streptococcus pneumoniae from four Spanish hospitals