Centro Nacional de Salud Pública, Instituto Nacional de Salud, Lima, Peru.
Epidemiología, Comando de Salud del Ejército, Lima, Peru.
J Med Microbiol. 2021 Jan;70(1). doi: 10.1099/jmm.0.001245. Epub 2020 Nov 16.
Asymptomatic carriers are a likely source of transmission of to close contacts who are placed at a higher risk for invasive meningococcal disease (IMD). Although ciprofloxacin-resistance is rare, there have been an increase in the reports of resistant isolates mainly in patients diagnosed with IMD, and little is known about the ciprofloxacin-resistance in the carrier populations. We performed a pharyngeal carriage study during a 2017 military setting outbreak in Peru, caused by a ciprofloxacin-resistant B. The isolates analysed came from two hospitalized cases and six asymptomatic carriers. Whole-genome sequence-based analysis was performed and showed that strains carrying the ThrIle mutation, in the gene encoding for subunit A of DNA gyrase (A), were responsible for the fluoroquinolone resistance (MICs ≥0.256 µg ml) and were closely related to highly virulent strains from France, Norway and the UK. Phylogenetic analysis of the A gene revealed that likely these Peruvian isolates acquired resistance through horizontal gene transfer from . Our study provides evidence for the emergence and propagation of ciprofloxacin-resistant B from asymptomatic carriers, and recommends the introduction of serogroup B vaccines for high-risk populations.
无症状携带者可能是传播给高危侵袭性脑膜炎奈瑟菌病（ IMD）密切接触者的来源。虽然 对环丙沙星的耐药性很少见，但对耐药分离株的报告有所增加，主要是在诊断为 IMD 的患者中，而对携带者人群中 对环丙沙星的耐药性知之甚少。我们在秘鲁 2017 年军事环境暴发期间进行了咽拭子携带研究，由对环丙沙星耐药的 B 引起。分析的分离株来自两名住院患者和六名无症状携带者。进行了全基因组序列分析，结果表明，携带 ThrIle 突变的菌株，在编码 DNA 拓扑异构酶 A 亚单位的基因中，导致氟喹诺酮类药物耐药（MIC≥0.256μg/ml），与法国、挪威和英国的高毒力菌株密切相关。A 基因的系统发育分析表明，这些秘鲁分离株可能通过水平基因转移从 获得了耐药性。我们的研究为无症状携带者中出现和传播环丙沙星耐药的 B 提供了证据，并建议为高危人群接种 B 群脑膜炎球菌疫苗。
