Trends towards Lower Antimicrobial Susceptibility and Characterization of Acquired Resistance among Clinical Isolates of Brachyspira hyodysenteriae in Spain
[EN] The antimicrobial susceptibility of clinical isolates of Brachyspira hyodysenteriae in Spain was moni- tored, and the underlying molecular mechanisms of resistance were investigated. MICs of tylosin, tiamu- lin, valnemulin, lincomycin, and tylvalosin were determined for 87 B. hyodysenteriae iso...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2011 |
| País: | España |
| Institución: | Universidad de León |
| Repositorio: | BULERIA. Repositorio Institucional de la Universidad de León |
| OAI Identifier: | oai:buleria.unileon.es:10612/25010 |
| Acceso en línea: | https://journals.asm.org/doi/10.1128/aac.01749-10 https://hdl.handle.net/10612/25010 |
| Access Level: | acceso abierto |
| Palabra clave: | Veterinaria Brachyspira hyodysenteriae 3109 Ciencias Veterinarias |
| Sumario: | [EN] The antimicrobial susceptibility of clinical isolates of Brachyspira hyodysenteriae in Spain was moni- tored, and the underlying molecular mechanisms of resistance were investigated. MICs of tylosin, tiamu- lin, valnemulin, lincomycin, and tylvalosin were determined for 87 B. hyodysenteriae isolates recovered from 2008 to 2009 by broth dilution. Domain V of the 23S rRNA gene and the ribosomal protein L3 gene were sequenced in 20 isolates for which the tiamulin MIC was >4 g/ml, presenting decreased suscep- tibility, and in 18 tiamulin-susceptible isolates (MIC < 0.125 g/ml), and all isolates were typed by multiple-locus variable-number tandem repeats analysis. A comparison with antimicrobial susceptibility data from 2000 to 2007 showed an increase in pleuromutilin resistance over time, doubling the number of isolates with decreased susceptibility to tiamulin. No alteration in susceptibility was detected for linco- mycin, and the MIC of tylosin remained high (MIC 50 > 128 g/ml). The decreased susceptibility to tylosin and lincomycin can be explained by mutations at position A2058 of the 23S rRNA gene (Escherichia coli numbering). A2058T was the predominant mutation, but A2058G also was found together with a change of the neighboring base pair at positions 2057 to 2611. The role of additional point mutations in the vicinity of the peptidyl transferase center and mutations in the L3 at amino acids 148 and 149 and their possible involvement in antimicrobial susceptibility are considered. An association between G2032A and high levels of tiamulin and lincomycin MICs was found, suggesting an increasing importance of this mutation in antimicrobial resistance of clinical isolates of B. hyodysenteriae |
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