Contribution of amino acid substitutions in ParE to quinolone resistance in Haemophilus haemolyticus revealed through a horizontal transfer assay using Haemophilus influenzae.
J Antimicrob Chemother
; 78(5): 1225-1230, 2023 05 03.
Article
em En
| MEDLINE
| ID: mdl-36949027
ABSTRACT
BACKGROUND:
In 2019, a high-level quinolone-resistant Haemophilus haemolyticus strain (levofloxacin MICâ=â16 mg/L) was isolated from a paediatric patient. In this study, we aimed to determine whether the quinolone resistance of H. haemolyticus could be transferred to Haemophilus influenzae and to identify the mechanism underlying the high-level quinolone resistance of H. haemolyticus.METHODS:
A horizontal gene transfer assay to H. influenzae was performed using genomic DNA or PCR-amplified quinolone-targeting genes from the high-level quinolone-resistant H. haemolyticus 2019-19 strain. The amino acids responsible for conferring quinolone resistance were identified through site-directed mutagenesis.RESULTS:
By adding the genomic DNA of H. haemolyticus 2019-19, resistant colonies were obtained on agar plates containing quinolones. Notably, H. influenzae grown on levofloxacin agar showed the same level of resistance as H. haemolyticus. Sequencing analysis showed that gyrA, parC and parE of H. influenzae were replaced by those of H. haemolyticus, suggesting that horizontal transfer occurred between the two strains. When the quinolone-targeting gene fragments were added sequentially, the addition of parE, as well as gyrA and parC, contributed to high-level resistance. In particular, amino acid substitutions at both the 439th and 502nd residues of ParE were associated with high-level resistance.CONCLUSIONS:
These findings indicate that quinolone resistance can be transferred between species and that amino acid substitutions at the 439th and 502nd residues of ParE, in addition to amino acid substitutions in both GyrA and ParC, contribute to high-level quinolone resistance.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Quinolonas
Tipo de estudo:
Prognostic_studies
Limite:
Child
/
Humans
Idioma:
En
Revista:
J Antimicrob Chemother
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Japão