English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/126424
Título

Molecular characterization of fluoroquinolone resistance in nontypeable haemophilus influenzae clinical isolates

AutorPuig, Carmen; Tirado-Vélez, José Manuel; Calatayud, Laura; Tubau, Fe; Garmendia, Juncal ; Ardanuy, Carmen; Marti, Sara; Campa, Adela G. de la; Liñares, Josefina
Fecha de publicaciónene-2015
EditorAmerican Society for Microbiology
CitaciónAntimicrobial Agents and Chemotherapy 59(1): 461-466 (2015)
ResumenNontypeable Haemophilus influenzae (NTHi) is a common cause of respiratory infections in adults, who are frequently treated with fluoroquinolones. The aims of this study were to characterize the genotypes of fluoroquinolone-resistant NTHi isolates and their mechanisms of resistance. Among 7,267 H. influenzae isolates collected from adult patients from 2000 to 2013, 28 (0.39%) were ciprofloxacin resistant according to Clinical and Laboratory Standards Institute (CLSI) criteria. In addition, a nalidixic acid screening during 2010 to 2013 detected five (0.23%) isolates that were ciprofloxacin susceptible but nalidixic acid resistant. Sequencing of their quinolone resistance-determining regions and genotyping by pulse-field gel electrophoresis and multilocus sequence typing of the 25 ciprofloxacin-resistant isolates available and all 5 nalidixic acid-resistant isolates were performed. In the NTHi isolates studied, two mutations producing changes in two GyrA residues (Ser84, Asp88) and/or two ParC residues (Ser84, Glu88) were associated with increased fluoroquinolone MICs. Strains with one or two mutations (n =15) had ciprofloxacin and levofloxacin MICs of 0.12 to 2 μg/ml, while those with three or more mutations (n=15) had MICs of 4 to 16 μg/ml. Long persistence of fluoroquinolone-resistant strains was observed in three chronic obstructive pulmonary disease patients. High genetic diversity was observed among fluoroquinolone-resistant NTHi isolates. Although fluoroquinolones are commonly used to treat respiratory infections, the proportion of resistant NTHi isolates remains low. The nalidixic acid disk test is useful for detecting the first changes in GyrA or in GyrA plus ParC among fluoroquinolone-susceptible strains that are at a potential risk for the development of resistance under selective pressure by fluoroquinolone treatment.
Versión del editorhttp://dx.doi.org/10.1128/AAC.04005-14
URIhttp://hdl.handle.net/10261/126424
DOI10.1128/AAC.04005-14
Identificadorese-issn: 1098-6596
issn: 0066-4804
Aparece en las colecciones: (IDAB) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
accesoRestringido.pdf15,38 kBAdobe PDFVista previa
Visualizar/Abrir
Mostrar el registro completo
 

Artículos relacionados:


NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.