结核分枝杆菌对氟喹诺酮类药物的耐药性研究进展

氟喹诺酮类药物在耐多药结核治疗中的应用日益广泛，但结核分枝杆菌对其耐药性也逐渐增加，特别是当不合理用药时更易发生。因此，研究其耐药机制，加强合理应用以控制耐药性的增长是非常有必要的。本文对氟喹诺酮类药物耐药状况、耐药机制等研究近况作一综述，为临床合理用药提供一定参考。     

Early Effects Triggered by Larrea divaricata Cav. on Murine Macrophages at Apoptotic Concentrations

Decoction and infusion of Larrea divaricata were tested at apoptotic concentrations (1 and 4 mg/ml) on peritoneal murine macrophages. Consistent changes were observed after incubation with 4 mg/ml decoction. Phagocytosis of zymosan, lysosomal enzyme activity, nitric oxide production, TNF-α release, and expression of CD14, TLR4, and CR3 increased significantly. Decoction at 1 and 4 mg/ml increased the binding of LPS-FITC. Apoptosis triggered by L. divaricata decoction is consequence of cell activation. The effects are independent of nordihydroguaiaretic acid. This “activation and death” could be the mechanism of L. divaricata to exert the antituberculosis effect known in folk medicine.     

Respiratory tract infection caused by Mycobacterium bovis in a black swan (Cygnus atratus)

A 3-year-old male black swan (Cygnus atratus), belonging to a private collection, died suddenly and was subjected to post mortem examination. At necropsy, caseous exudate was observed in the lungs and air sacs; granulomatous lesions characterized by epithelioid macrophages and abundant mycobacteria were observed microscopically. Avian tuberculosis associated with Mycobacterium bovis was confirmed by bacteriologic isolation, biochemical tests and molecular methods. The organism was identified as spoligotype SB0140, which is frequently found in cattle and people in North America. In this case, interspecies transmission could have been the source of infection because the swan cohabited with cattle.     

Nontuberculous mycobacterial infection with concurrent IgG4‐related lymphadenopathy

Disseminated nontuberculous mycobacteria (NTM) infection with concurrent IgG4‐related lymphadenopathy has not been reported. We described a patient with neutralizing autoantibodies to interferon‐gamma (IFN‐γ) and elevated levels of serum IgG4 presenting with generalized lymphadenopathy and reactive dermatosis. Histologically, lymph nodes (LNs) showed effaced nodal architecture with polymorphic infiltrates, mimicking angioimmunoblastic T‐cell lymphoma. Both the absolute number and the ratio of IgG4+ plasma cells to IgG+ plasma cells were increased. Mycobacterium abscessus was isolated from cultures of LNs, and demonstrated by polymerase chain reaction‐restriction fragment length polymorphism. The skin biopsy showed neutrophilic dermatosis, consistent with Sweet syndrome. The patient met the criteria of both adult‐onset immunodeficiency syndrome and IgG4‐related lymphadenopathy. This case provides evidence of disseminated NTM infection with concurrent type III IgG4‐related lymphadenopathy in the patient with anti‐IFN‐γ autoantibodies.     

儿童结核病耐药特点及耐多药相关因素分析

目的 了解儿童结核病的耐药现况,发现儿童耐多药相关的危险因素。方法 收集沈阳市第十人民医院2017年1月31日至2019年12月31日收治的≤18岁的结核病患者314例,男178例,女136例,年龄1~18岁,中位年龄(四分位数)[M(Q₁,Q₃)]为17(15,18)岁,初治253例,复治61例。分析314例患者培养阳性且菌种鉴定为结核分枝杆菌(MTB)的临床分离株的药物敏感性试验结果。采用多因素非条件logistic回归分析儿童耐药结核病的危险因素。结果 314例患者的MTB临床分离株总耐药率、初治耐药率和复治耐药率分别为27.1%(85/314)、20.9%(53/253)和52.5%(32/61),复治耐药率明显高于初治耐药率(χ²=24.771,P=0.000);总耐多药率、初治耐多药率和复治耐多药率分别为10.8%(34/314)、6.3%(16/253)和29.5%(18/61),复治耐多药率明显高于初治耐多药率(χ²=27.360,P=0.000)。logistic多因素回归分析表明,复治(OR=5.671,95%CI=2.228~14.435,P=0.000)、14~18岁年龄组(OR=2.235,95%CI=1.568~3.562,P=0.032)、并发营养不良(OR=1.908,95%CI=1.337~2.447, P=0.034)、吸烟(OR=1.225,95%CI=1.013~2.740,P=0.046)是儿童患者发生耐多药结核病的危险因素。结论 儿童结核病耐药现状严峻,复治、14~18岁年龄组、并发营养不良、有吸烟史是儿童患者发生耐多药的危险因素。     

福建省龙岩市411例肺结核患者对利福平和异烟肼耐药状况的研究

目的 回顾性分析福建省龙岩市411例肺结核患者对利福平和异烟肼的耐药状况,为当地结核病防治工作提供科学依据。方法 收集2016年5月12日至2019年8月17日福建省龙岩市第二医院门诊及收住入院并确诊为肺结核的411例患者,其中初治患者312例,复治患者99例。作者对两组患者411株结核分枝杆菌临床分离株采用基因芯片技术进行利福平与异烟肼耐药性及其相关耐药基因突变位点的检测。采用Excel 2003和SPSS 20.0软件进行数据的整理和统计学分析,计数资料的比较采用χ ²检验,以P<0.05为差异有统计学意义。结果 411例肺结核患者中,初治患者利福平和异烟肼任一位点突变率[9.3%(29/312)]明显低于复治任一位点突变率[54.5%(54/99)](χ ²=95.483,P<0.05);初治患者同时耐利福平和异烟肼的耐药率(简称“耐两药率”)[2.9%(9/312)]明显低于复治耐两药率[33.3%(33/99)](χ ²=75.944,P<0.05)。利福平和异烟肼任一位点突变率为20.2%(83/411),其中利福平耐药基因ropB的突变率为5.4%(22/411),20例为单一位点突变,2例为双位点突变,以531(C→T)突变频率最高[40.9%(9/22)];异烟肼耐药基因katG和inhA的突变率为4.6%(19/411),其中13例为katG基因突变,6例为inhA基因突变,以315(G→C)突变频率最高[63.2%(12/19)];耐两药率为10.2%(42/411),其中40例为双位点突变,1例为三位点突变,1例是四位点突变,以531(C→T)315(G→C)突变频率最高[47.6%(20/42)]。结论 龙岩市肺结核耐药患者以耐两药为主,复治患者耐两药的情况较初治患者严重,防治形势严峻。     

杨梅素通过磷脂酰肌醇3-激酶/蛋白激酶B/哺乳动物雷帕霉素靶蛋白信号通路诱导MTB感染巨噬细胞发生自噬的研究

目的 对杨梅素通过磷脂酰肌醇3-激酶/蛋白激酶B/哺乳动物雷帕霉素靶蛋白(PI3K/Akt/mTOR)信号通路诱导MTB感染的巨噬细胞发生自噬进行研究,从而探讨杨梅素抗结核作用的机理。方法 用CCK8法检测杨梅素对细胞增殖的影响,确定安全的用药范围;以H37Ra菌株感染的小鼠巨噬细胞Raw 264.7为模型组,并设空白组和药物处理组。按感染复数(MOI,即细菌∶细胞=10∶1)加入模型组、药物处理组,共孵育4h后,磷酸盐缓冲液(PBS)洗3次以弃掉未进入胞内的MTB。药物处理组分别用不同浓度(12.5、25、50、100μmol/L)的杨梅素作用24h, Western blot法检测自噬相关蛋白即“微管相关蛋白1轻链3-Ⅱ(LC3-Ⅱ)和p62”表达水平的变化,并以此筛选出杨梅素促进自噬的最佳作用浓度;100μmol/L杨梅素作用于感染细胞72h后,0.1%聚乙二醇辛基苯基醚(Triton X-100)冰上裂解细胞10min,菌落形成单位(CFU)法检测巨噬细胞胞内荷菌量;杨梅素作用感染细胞不同时间(30、60、180min)后Western blot测定PI3K/Akt/mTOR信号通路中Akt、mTOR的磷酸化水平。以Image J软件做蛋白定量分析,用GraphPad Prism 7.0制图,采用单因素方差分析(ANOVA)进行统计分析,以P<0.05为差异有统计学意义。结果 杨梅素在100μmol/L浓度以下细胞生存率在90%左右,对细胞毒性较小;Western blot结果显示:与模型组(0.52±0.01)相比,杨梅素不同浓度(12.5、25、50、100μmol/L)处理均能促进LC3Ⅱ的表达(0.59±0.02、 0.65±0.01、 0.71±0.01、 0.83±0.01),差异有统计学意义(t=2.97、P=0.04,t=7.91、P=0.00,t=9.77、P=0.00,t=16.37、P=0.00);而较模型组p62蛋白(0.86±0.02),药物处理亦能抑制p62的表达(0.72±0.01、0.86±0.00、0.60±0.02、0.58±0.01),25μmol/L杨梅素处理组差异无统计学意义(t=0.81、P=0.46),12.5、50、100μmol/L处理组差异均有统计学意义(t=6.50、P=0.00,t=9.53、P=0.00,t=12.01、P=0.00);杨梅素促进自噬的最佳药物浓度为100μmol/L;100μmol/L杨梅素作用于感染细胞72h后,对胞内MTB的抑制率为21.02%;模型组细胞在MTB感染后30、60、180min时,PI3K/Akt/mTOR通路中Akt蛋白的磷酸化(p-Akt)水平(1.23±0.01、1.52±0.01、0.74±0.02)明显增加,而杨梅素作用相同的时间后,可明显抑制Akt蛋白的磷酸化(0.99±0.01、0.96±0.01、0.43±0.01),差异有统计学意义(t=27.60、P=0.00,t=30.06、P=0.00,t=18.60、P=0.00);而模型组磷酸化mTOR(p-mTOR)蛋白水平仅在MTB感染后180min(0.57±0.00)明显增加(t=94.61、P=0.00),杨梅素作用180min亦能抑制mTOR蛋白的磷酸化(0.46±0.01),差异有统计学意义(t=21.60、P=0.00)。结论 杨梅素通过抑制Akt和mTOR蛋白的磷酸化来抑制PI3K/Akt/mTOR通路,从而诱导MTB感染的巨噬细胞发生自噬来杀灭胞内的MTB。     

Mycobacterium Chimaera: Clinical and medico-legal considerations starting from a case of sudden acoustic damage

Mycobacterium Chimaera is a microorganism that can cause nosocomial infections particularly in patients undergoing cardiac surgery. The specific case presented herein shows an original clinical presentation of the infection: sudden unilateral deafness as a result of septic embolization. Medico-legal experts appointed by the court in a civil liability dispute analyzed the case and submitted their expert opinion. This article analyzes the peculiar and innovative aspect of professional liability that can be attributed to the healthcare facility and the manufacturer of the equipment used in the operating room from a medical-legal point of view.