Quinolone Resistance Determinants of Clinical Salmonella Enteritidis in Thailand.
Microb Drug Resist
; 23(7): 885-894, 2017 Oct.
Article
en En
| MEDLINE
| ID: mdl-28437229
ABSTRACT
Salmonella Enteritidis has emerged as a global concern regarding quinolone resistance and invasive potential. Although quinolone-resistant S. Enteritidis has been observed with high frequency in Thailand, information on the mechanism of resistance acquisition is limited. To elucidate the mechanism, a total of 158 clinical isolates of nalidixic acid (NAL)-resistant S. Enteritidis were collected throughout Thailand, and the quinolone resistance determinants were investigated in the context of resistance levels to NAL, norfloxacin (NOR), and ciprofloxacin (CIP). The analysis of point mutations in type II topoisomerase genes and the detection of plasmid-mediated quinolone resistance genes showed that all but two harbored a gyrA mutation, the qnrS1 gene, or both. The most commonly affected codon in mutant gyrA was 87, followed by 83. Double codon mutation in gyrA was found in an isolate with high-level resistance to NAL, NOR, and CIP. A new mutation causing serine to isoleucine substitution at codon 83 was identified in eight isolates. In addition to eighteen qnrS1-carrying isolates showing nontypical quinolone resistance, one carrying both the qnrS1 gene and a gyrA mutation also showed a high level of resistance. Genotyping by multilocus variable number of tandem repeat analysis suggested a possible clonal expansion of NAL-resistant strains nationwide. Our data suggested that NAL-resistant isolates with single quinolone resistance determinant may potentially become fluoroquinolone resistant by acquiring secondary determinants. Restricted therapeutic and farming usage of quinolones is strongly recommended to prevent the emergence of fluoroquinolone-resistant isolates.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Salmonella enteritidis
/
Infecciones por Salmonella
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Girasa de ADN
/
Farmacorresistencia Bacteriana
/
Mutación
Tipo de estudio:
Prevalence_studies
/
Prognostic_studies
/
Risk_factors_studies
Límite:
Humans
País/Región como asunto:
Asia
Idioma:
En
Revista:
Microb Drug Resist
Asunto de la revista:
MICROBIOLOGIA
/
TERAPIA POR MEDICAMENTOS
Año:
2017
Tipo del documento:
Article
País de afiliación:
Tailandia