Clonal success of piliated penicillin nonsusceptible pneumococci
| Autor: | Rino Rappuoli, F. Henriques, Karin Sjöström, Staffan Normark, Jenny Fernebro, Barbara Albiger, Martin Andersson, Birgitta Henriques-Normark, Sarah Browall, Jessica Dagerhamn, Michèle A. Barocchi, Christel Blomberg, Eva Morfeldt, Monica Moschioni |
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| Rok vydání: | 2007 |
| Předmět: |
Serotype
medicine.drug_class Antibiotics Clone (cell biology) Penicillins Biology medicine.disease_cause Bacterial Adhesion Pilus Microbiology Antibiotic resistance Nasopharynx Streptococcus pneumoniae medicine Humans Sweden Multidisciplinary Genetic Variation Biological Sciences Virology Penicillin Carriage Trans-Activators Genome Bacterial medicine.drug |
| Zdroj: | Proceedings of the National Academy of Sciences. 104:12907-12912 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.0705589104 |
| Popis: | Antibiotic resistance in pneumococci is due to the spread of strains belonging to a limited number of clones. The Spain 9V -3 clone of sequence type (ST)156 is one of the most successful clones with reduced susceptibility to penicillin [pneumococci nonsusceptible to penicillin (PNSP)]. In Sweden during 2000–2003, a dramatic increase in the number of PNSP isolates was observed. Molecular characterization of these isolates showed that a single clone of sequence type ST156 increased from 40% to 80% of all serotype 14, thus causing the serotype expansion. Additionally, during the same time period, we examined the clonal composition of two serotypes 9V and 19F: all 9V and 20% of 19F isolates belonged to the clonal cluster of ST156, and overall ≈50% of all PNSP belonged to the ST156 clonal cluster. Moreover, microarray and PCR analysis showed that all ST156 isolates, irrespective of capsular type, carried the rlrA pilus islet. This islet was also found to be present in the penicillin-sensitive ST162 clone, which is believed to be the drug-susceptible ancestor of ST156. Competitive experiments between related ST156 serotype 19F strains confirmed that those containing the rlrA pilus islet were more successful in an animal model of carriage. We conclude that the pilus island is an important biological factor common to ST156 isolates and other successful PNSP clones. In Sweden, a country where the low antibiotic usage does not explain the spread of resistant strains, at least 70% of all PNSP isolates collected during year 2003 carried the pilus islet. |
| Databáze: | OpenAIRE |
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