Earlier generation quinolones can be useful in identifying Haemophilus influenzae strains with low susceptibility to quinolone isolated from paediatric patients
Earlier generation quinolones can be useful in identifying Haemophilus influenzae strains with low susceptibility to quinolone isolated from paediatric patients
复制标题
早期的喹诺酮类药物可用于鉴定从儿科患者中分离出的对喹诺酮类药物敏感性较低的流感嗜血杆菌菌株
DOI：
10.1099/jmm.0.001027
复制
发表时间：
2019
影响因子：
3
通讯作者：
Noguchi Norihisa
中科院分区：
文献类型：
--
作者：
Tanaka Emi;Wajima Takeaki;Noguchi Norihisa
目的：最近在日本儿科领域出现了对喹诺酮类药物敏感性较低的流感嗜血杆菌菌株。这些菌株在常规药敏试验中被判定为“敏感”，尽管它们在喹诺酮治疗后可能存活。因此，我们的目的是建立一个简单的和成本效益的鉴定方法，低敏感菌株的纸片扩散法。方法：共使用33个H. influenzaecenteral分离株和对照菌株。在纸片扩散法中，使用左氧氟沙星、诺氟沙星、萘啶酸和哌哌甲酯酸。结果：所有供试菌株在左氧氟沙星和诺氟沙星片上均形成明显的抑菌圈。相比之下，低敏感性菌株均未显示出对萘啶酸的抑制区，而在GyrA和ParC中具有氨基酸取代的低敏感性菌株均未显示出对哌啶酸盘的抑制区，表明低-通过早期喹诺酮类药物抑菌圈的存在与否，可以以高灵敏度和特异性检测敏感菌株。从萘啶酸和哌哌甲酯酸中提取的DNA可以检测出具有氨基酸取代的低敏感性菌株，而不需要遗传分析。这项测试可以帮助减少不适当和不必要的氟喹诺酮类药物的使用。
Purpose.Haemophilus influenzaestrains with low susceptibility to quinolones have recently emerged in the paediatric field in Japan. These strains are judged as ‘susceptible’ in routine susceptibility tests, although they may survive after quinolone treatment. Therefore, we aimed to construct a simple and cost-effective identification method for low-susceptibility strains using disc diffusion assays.Methodology.A total of 33H.influenzaeclinical isolates and a control strain were used. For the disc diffusion assay, levofloxacin, norfloxacin, nalidixic acid and pipemidic acid were employed. Correlations between the inhibition zone diameter and amino acid substitutions were evaluated.Results.All of the tested strains formed clear inhibition zones on both levofloxacin and norfloxacin discs. By contrast, none of the low-susceptibility strains showed inhibition zones against nalidixic acid, while the low-susceptibility strains with amino acid substitutions in both GyrA and ParC did not show inhibition zones against pipemidic acid discs, indicating that low-susceptibility strains can be detected with high sensitivity and specificity by the presence or absence of inhibition zones for earlier quinolones.Conclusion.A disc diffusion test combining results from nalidixic acid and pipemidic acid can detect low-susceptibility strains harbouring amino acid substitutions without the need for genetic analysis. This test can help reduce inappropriate and unnecessary fluoroquinolone use.