1－取代－7－〔3－（乙胺基甲基）－1－吡咯烷基〕－6，8－二氟－1，4－二氢－4－氧喹啉－3－羧酸N_1位定量构效关系的量子化学研究

本文利用ＣＮＤＯ／２研究了１－取代－７－〔（３－（乙胺基甲基）－１－吡咯烷基〕－６，８－二氟－１，４－二氢－４－氧喹啉－３－羧酸Ｎ１位不同取代基的药效构象，首次报道了以第四最低空轨道能（ＦＵＭＯ），超离域度、前沿电子密度等指标与Ｎ１位取代基的立体摩尔长度、最小最大宽度等结合的Ｎ１位定量构效关系，稍优于文献用经验参数ＵＮＳＡＴ的结果，研究表明Ｎ１位的活性不仅与立体摩尔长度有关，还与电性效应有关，支持了Ｄｏｍａｇａｌａ以不饱和度参数（ＵＮＳＡＴ）所得的结论，但ＵＮＳＡＴ的意义不十分明确，本研究的量化指标意义很清楚。     

5种喹诺酮类抗菌剂治疗老年性肺炎的疗效评价

目的 评价左氧氟沙星、培氟沙星、氟罗沙星、氧氟沙星和洛美沙星对肺炎的临床疗效。方法 采用随机对照法，每种药物治疗130例老年肺炎患者，对痰培养细菌行药敏试验，疗效及不良反应进行比较。结果 药物敏感性优良次序为左氧氟沙星、培氟沙星、氟罗沙星、氧氟沙星、洛美沙星；临床治愈率分别为58．46％、56．92％、55．38％、52．31％、47．69％，有效率分别为87．69％、83．08％、81．54％、80．00％、72．37％；不良反应率为6．15％、10．77％、16．92％、7．69％、13。85％。结论 左氧氟沙星疗效高，不良反应少，是喹诺酮类治疗老年性肺炎的首选药物。     

A successful antimicrobial therapeutic strategy for the discitis caused by Aggregatibacter actinomycetemcomitans under unknown drug susceptibility: A case report

Aggregatibacter actinomycetemcomitans is well-known as the pathogen of gingivitis or periodontitis, and discitis or vertebral osteomyelitis cases caused by this organism have rarely been reported. Ampicillin or amoxicillin has been used in the previously reported discitis cases; however, no cases have been reported that is treated with levofloxacin. We report the first published case we chose levofloxacin to treat. We failed to perform the susceptibility testing because of the poor growth and fastidious nature of the organism, and the result of susceptibility of amoxicillin was unclear. Levofloxacin, which A. actinomycetemcomitans is usually susceptible to, can be an effective alternative oral antimicrobial agent in such cases.     

Characteristics of antibiotic resistance and sequence type of Acinetobacter baumannii clinical isolates in Japan and the antibacterial activity of DS-8587

DS-8587 is a novel broad-spectrum fluoroquinolone with extended antimicrobial activity against both Gram-positive and Gram-negative pathogens. In this study, we evaluated the antibacterial activity and mechanism of DS-8587 in 31 quinolone-resistant Acinetobacter baumannii clinical isolates. Efflux pump and qnr genes, mutations in quinolone resistance-determining regions of target enzymes, and sequence types determined by multilocus sequence typing were analyzed. Forty-two quinolone-susceptible clinical isolates were analyzed for comparison. For susceptibility testing, DS-8587 exhibited more effective antibacterial activity when compared with ciprofloxacin and levofloxacin. When combined with the efflux pump inhibitor 1-(1-napthylmethyl)-piperazine, the MIC of DS-8587 was less affected when compared with the MIC exhibited by combined ciprofloxacin and 1-(1-napthylmethyl)-piperazine. The efflux pump genes adeA/adeB/adeC and regulatory elements adeR/adeS were detected in 23 of 31 quinolone-resistant isolates. The qnrA/qnrB/qnrS genes were not detected in any A. baumannii isolates analyzed. Mutations in quinolone resistance-determining regions were observed in all 31 quinolone-resistant isolates. Multilocus sequence typing analyses revealed that 22 of 31 quinolone-resistant isolates belonged to ST-2, corresponding to international clonal lineage II. In conclusion, DS-8587 exhibits potent antibacterial activity against quinolone-resistant A. baumannii isolates that harbor mutations in quinolone resistance-determining regions. In the presence of the efflux pump inhibitor 1-(1-napthylmethyl)-piperazine, no significant changes were observed in the MIC for DS-8587. DS-8587 should be considered as a treatment option for A. baumannii including ST-2 strains that are predominant among the quinolone-resistant A. baumannii isolates found in Japan.     

Dissemination of quinolone low-susceptible Haemophilus influenzae ST422 in Tokyo,Japan

IntroductionHaemophilus influenzae with a reduced susceptibility to quinolones (quinolone low-susceptible H. influenzae) has recently emerged in Japan. In addition, the regional outbreak of the quinolone low-susceptible H. influenzae ST422 clone has been reported. In this study, we isolated this clone from an acute care hospital located in a geographically different area from the previous outbreak and characterised the nature of this clone.MethodsEighty-nine H. influenzae isolated between 2017 and 2019 were tested. The antimicrobial susceptibility was determined by the broth dilution method. The genetic background was analysed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. Growth ability and β-lactamase acquisition were evaluated by growth curve analysis and conjugative transfer experiments, respectively.ResultsQuinolone low-susceptible isolates accounted for 4.2% (1/24) in 2018 and 13.9% (5/36) in 2019. Most of the quinolone low-susceptible strains (83.3%) were classified as ST422 and had amino acid substitutions in quinolone resistance-determining regions in both GyrA and ParC. The patients’ backgrounds were highly diverse. In addition, these isolates showed the same PFGE pattern as outbreak strains. The growth of ST422 clone was relatively faster than other clones. Furthermore, ST422 clone was able to acquire β-lactamase from a β-lactamase positive strain by horizontal transfer, becoming highly resistant to β-lactams.ConclusionOur study indicated that the quinolone low-susceptible H. influenzae ST422 clone has been spreading in the community undetected. In addition, this clone has the potential to grow faster and become more resistant through exogenous gene transfer. Therefore, ST422 clone should be monitored attention throughout Japan.     

喹诺酮类药物对老年患者神经系统影响的观察与护理对策

目的：由于老年患者使用喹诺酮类药物后神经系统反应率高且严重,为了提高老年患者喹诺酮类药物用药后的生活安全展开研究。方法：通过3年时间对135例使用喹诺酮类药的70岁以上老年患者,观察药物对其神经系统产生的影响,对不同神经系统症状出现的比例进行分析。结果：发现70岁以上老年患者神经系统反应的发生率高达13.51%,而且存在多种反应同时出现的问题,对患者的生活安全造成非常大的影响,有跌倒、坠床、意外伤害等风险暴露。结论：护理人员通过细致全面的护理观察、护理人员培训、强化安全宣教、提供个性化的安全护理措施,最大程度的及早发现安全隐患,不但保障了老年患者住院期间的安全而且对患者出院后的安全也起到了一定的警示作用。     

加替沙星和司帕沙星的光动力抗菌研究

目的 喹诺酮作为抗菌药物在临床上具有一定的光敏毒副作用,那么喹诺酮化合物是否可以作为光敏抗菌药物应用呢？ 基于上述目的我们研究了加替沙星 (GFLX)、司帕沙星 (SPFX) 的光动力抗菌活性。方法 本文报道了 GFLX、SPFX 在 650、450 和 365nm 及白光不同光照波长及激光能量密度与暗反应条件下对耐药菌株金黄色葡萄球菌 (MRSA)、铜绿假单胞菌 (P. aeruginosa)、大 肠埃希菌 (E. coli) 的抗菌活性。结果 GFLX、SPFX 对 MRSA、P. aeruginosa、E. coli 暗毒性最低抑菌浓度 (MIC) ≤ 2.5μg/mL; 最低杀菌浓度 (MBC) ≤ 20μg/mL。GFLX 在 450nm 光照条件下对 MRSA、P. aeruginosa、E. coli 的 MIC 分别为 0.15、0.31 和 0.07μg/ mL;MBC 分别为 0.62、1.25 和 0.15μg/mL。相应的 SPFX 在 650nm 光照条件下抗菌活性分别为 0.31、0.31 和 0.07μg/mL;MBC 分 别为 20、5 和 0.15μg/mL。进一步研究表明 GFLX、SPFX 光动力灭菌活性及细胞毒性具有光波长及能量依赖性。结论 光照可以 一定程度上增加 GFLX 和 SPFX 的抗菌活性,但提升能力有限,在此区间其光敏毒副作用有限,这类药物不会伤及细胞,因而喹 诺酮类药物在临床上不足以作为光敏抗菌药物使用,相对安全。     

阴沟肠杆菌质粒介导耐喹诺酮类药物的机制研究

目的了解深圳地区阴沟肠杆菌中qnrA基因的流行情况、基因定位及其介导喹诺酮耐药性产生的机制。方法收集临床分离的阴沟肠杆菌45株,采用PCR法结合测序的技术筛查qnrA基因,大质粒提取技术、Southern杂交和接合传递试验进行质粒定位,琼脂对倍稀释法进行药物敏感性检测。结果45株阴沟肠杆菌中,7株PCR法及测序证实为qnrA基因。7株菌中6株菌所携质粒被成功提取并进行Southern杂交,qnrA基因定位于80~200kb大小的低拷贝数天然质粒上。4株菌成功进行接合传递试验,使接合子对环丙沙星的MIC值提高了32~64倍。结论质粒介导的喹诺酮耐药基因qnrA在深圳地区阴沟肠杆菌中具有较高的流行率,可能是导致阴沟肠杆菌对喹诺酮类抗菌药获得性耐药的重要原因。     

Synthesis and antiproliferative activity of 1-[(sub)]-6-fluoro-3-[(sub)]-1, 3,4-oxadiazol-2-yl-7-piperazino-1, 4-dihydro-4-quinolinone derivatives

A series of 1-[(sub)]-6-fluoro-3- [(sub)]-1, 3, 4-oxadiazol-2-yl-7-piperazino-1, 4-dihydro 4-quinolinones were synthesized by the reaction between ciprofloxacin and norfloxacin with an appropriate acid hydrazide in phosphorous oxychloride. All newly synthesized compounds were evaluated for their antiproliferative activities against human lung tumor cell lines (A 549). Fluoroquinolone with oxadiazole (Q ₂ ) 1-cyclopropyl-6-fluoro-3- [5-(4-nitrophenyl)-1,3,4-oxadiazol-2-yl]-7-piperazino-1, 4-dihydro-4-quinolinone was found to be the most active compound in vitro with a half-maximal inhibitory concentration (IC₅₀) of 9.0 μg/mL.     

临床分离耐喹诺酮阴沟肠杆菌gyrA基因突变的研究

目的：检测临床分离耐喹诺酮阴沟肠杆菌DNA促旋酶gyrA基因突变情况。方法：收集临床分离耐喹诺酮阴沟肠杆菌30株及敏感株10株，测定其对萘啶酸、环丙沙星、氧氟沙星的最低抑菌浓度(MIC)；用聚合酶链反应(PCR)扩增gyrA基因部分片断，对PCR产物进行限制性片断长度多态性(PCR—RFLP)及单链构象多态性(PCR—SSCP)分析，检测gyrA突变情况。结果：30株耐喹诺酮菌株都检测到gyrA基因突变，PCR—RFLP均显示两条不同于敏感株的电泳带，其PCR—SSCP则检测到4种不同于敏感菌的迁徙率条带；而10株敏感菌均未检测到gyrA基因突变。结论：阴沟肠杆菌对喹诺酮类药物耐药性与gyrA基因突变有关，gyrA基因第83位氨基酸密码子突变可能为其耐药的主要原因。