KPC型碳青霉烯酶研究进展

碳青霉烯类抗生素包括亚胺培南、美罗培南和厄他培南等是治疗肠杆菌科细菌尤其是产超广谱β内酰胺酶(ESBLs)及AmpC酶等多重耐药菌株引起感染的最有效的抗菌药物[1].然而,随着碳青霉烯类抗生素耐药肠杆菌科细菌(carbapenem-resistant Enterobacteriaceae,CRE)的出现及不断增多,该类药物的临床应用受到严峻的挑战.     

鲍曼不动杆菌对碳青霉烯类抗生素耐药性研究

目的 :调查我院鲍曼不动杆菌对亚胺培南等 7种抗菌药的敏感性 ,指导临床用药。方法 :使用Etest法测定 7种抗菌药对 2 5株鲍曼不动杆菌的最低抑菌浓度 (MIC) ,回顾性分析 2 5株鲍曼不动杆菌的临床特点。结果 :7种抗菌药中氨苄西林 舒巴坦对鲍曼不动杆菌的抗菌活性最高 (敏感率 76 % ,MIC50 /MIC90 4 / >2 5 6mg /L) ,其次为亚胺培南、美罗培南和环丙沙星(敏感率均 72 % ,MIC50 /MIC90 分别为 1.5 / >32、2 / >32、0 .38/ >32mg /L) ,阿米卡星、头孢吡肟和头孢他啶活性较低 (敏感率分别为 6 0 %、5 2 %、4 8% ;MIC50 /MIC90 分别为 12 / >2 5 6、8/ >2 5 6、16 / >2 5 6mg /L)。 7/ 2 5株鲍曼不动杆菌对碳青霉烯类高度耐药 ,MIC均大于 16mg /L ,但均对氨苄西林 舒巴坦和环丙沙星敏感 ,MIC分别为 3～ 8mg /L和0 .0 0 8～ 0 .38mg /L。这 7株耐碳青霉烯类抗菌药的鲍曼不动杆菌 5株来自呼吸科 ,其中 6例近期曾使用亚胺培南和 (或 )美罗培南治疗。结论 :我院鲍曼不动杆菌对碳青霉烯类抗菌药耐药率较高 ,应加强对该类抗菌药使用的监控     

重症急性胰腺炎预防性使用碳青霉烯类抗生素的Meta分析

目的 通过Meta分析的方法对重症急性胰腺炎(SAP)治疗中预防性应用碳青霉烯类抗生素的疗效进行评价.方法 检索1975至2012年9月公开发表的所有急性胰腺炎(CT证实有胰腺坏死)与预防性应用碳青霉烯类抗生素的随机临床对照研究.依照入选和排除标准,最终纳入6篇随机对照试验研究,提取所需数据,应用RevMan5.0软件进行疗效分析.结果 预防性应用碳青霉烯类抗生素组与安慰剂组相比,能降低急性重症胰腺炎患者的胰腺感染率(OR =0.55,95％ CI:0.33 ～0.91,P=0.02)和胰腺外感染率(OR=0.48,95％ CI:0.27 ～0.82,P=0.008),但不能降低手术率和病死率(P均＞0.05).结论 预防性应用碳青霉烯类抗生素,能降低胰腺及胰腺外感染率,改善局部症状,但不能从根本上改善急性重症胰腺炎患者的预后.     

鲍曼不动杆菌对碳青霉烯类抗生素耐药机制研究

目的研究鲍曼不动杆菌对碳青霉烯类抗生素的耐药机制。方法用Etest法和微量肉汤稀释法测定11种抗生素对30株亚胺培南耐药的鲍曼不动杆菌的最低抑菌浓度(M IC值),三维实验法测定β-内酰胺酶表型,用PCR扩增9种β-内酰胺酶编码基因。结果11种抗菌药物中,除多粘菌素B耐药率为23.3%,环丙沙星的耐药率为87.7%,其他抗生素的耐药率均在90%以上。以头孢曲松作为底物,30株不动杆菌中单产ESBLs的33.3%(10/30),单产AmpC酶的3.3%(1/30),同时产ESBLs和AmpC酶的23.3%(7/30),产可水解头孢曲松但不能被克拉维酸和氯唑西林所抑制的酶的26.7%(8/30),未检测到产酶的13.3%(4/30)。VIM-1、VIM-2、OXA-24、CTX-M-2、IMP-1、VEB-1编码基因均阴性。27株菌检测到OXA-23、PER-1和AmpC编码基因中的2种或3种,测序证实与GenBank相应序列同源性均在98%以上。26号菌的PER-1序列与GenBank中登录的铜绿假单胞菌PER-1序列(AZ21957)相比,在第617位核苷酸发生了突变(A→C),该序列已在GenBank登录(登录号:DQ341275)。结论鲍曼不动杆菌的耐药性与其产生OXA-23、PER-1和AmpC酶密切相关。     

铜绿假单胞菌对碳青霉烯类抗生素耐药机制的研究进展

随着亚胺培南、美罗培南等碳青霉烯类抗菌药物在临床上的广泛应用，近年来细菌对该类抗菌药物的耐药率正在逐年上升，其中以非发酵菌中的铜绿假单胞菌的耐药率上升尤为显著。目前临床上发现的耐碳青霉烯类的铜绿假单胞菌大多是多重耐药菌株，不但对碳青霉烯类和其他的β内酰胺类耐药，     

丙戊酸钠血药浓度与抗癫痫作用的相关性

目的:分析丙戊酸钠防治癫痫的血药浓度监测结果,探讨其临床合理用药方法.方法:采用药物浓度自动分析仪(TDX)测定丙戊酸钠血药浓度,并分析其与抗癫痫的疗效关系.结果:丙戊酸钠血药浓度在50～100 mg/L时的抗癫痫作用好,不良反应少;<50 mg/L时抗癫痫作用差,而>100 mg/L时的不良反应多.结论:丙戊酸钠的血药浓度与疗效有较好的相关性,应加强对丙戊酸钠的血药浓度监测,提高临床合理用药.     

碳青霉烯类耐药鲍曼不动杆菌金属酶检测及临床意义

近年来随着碳青霉烯类药物在医院中的广泛使用,碳青霉烯类耐药鲍曼不动杆菌（CRAB）的分离率逐年增高［1,2］。金属β内酰胺酶（MBL）能水解碳青霉烯类抗生素,是导致细菌对该类抗生素耐药的重要机制,特别是产NDM-1菌株的出现,引起人们对产金属酶菌株的极大关注。因此,对MBL的检测具有重要的临床意义。为了解本院分离的鲍曼不动杆菌中金属酶的分布情况,作者对临床分离的78株CRAB进行MBL表型筛选试验和基因型测定,现报告如下。     

广泛耐药鲍曼不动杆菌耐碳青霉烯类抗生素膜蛋白机制研究

目的研究膜蛋白在鲍曼不动杆菌耐碳青霉烯类抗生素中的作用。方法采用琼脂纸片扩散法(K-B法)及琼脂稀释法从84株广泛耐药鲍曼不动杆菌中筛选出8株仅对多黏菌素敏感、1株全敏感临床株。采用PAβN外排泵抑制试验检测其外排泵表型。超声破碎法提取鲍曼不动杆菌外膜蛋白,双向电泳技术比较鲍曼不动杆菌耐药株及敏感株膜蛋白表达谱,差异蛋白进行胶内酶切,肽混合物进行质谱分析,将肽质量指纹谱数据输入互联网上蛋白质数据库进行检索和质谱鉴定分析。结果 PAβN抑制试验显示受试8株菌中4株亚胺培南MIC值下降≤原值的1/4,而美罗培南MIC值下降至1/4及以下。耐药菌株和敏感菌株差异膜蛋白组学鉴定出(CarO、OmpA和推测分子量为41 ku外排泵膜蛋白。结论本次试验中膜孔蛋白CarO表达缺失可能参与鲍曼不动杆菌对碳青霉烯抗生素耐药,外排泵过度表达可能参与细菌对美罗培南的耐药。     

Possible Mechanism by Which the Carbapenem Antibiotic Panipenem Decreases the Concentration of Valproic Acid in Plasma in Rats

There is evidence indicating that the carbapenem antibiotic panipenem decreases plasma concentrations of valproic acid (VPA) in epileptic patients during VPA therapy. The mechanism for panipenem-induced changes in the pharmacokinetics of VPA was investigated in rats with and without bile duct cannulation. The effect of panipenem on the pharmacokinetics of diclofenac, which undergoes extensive enterohepatic recirculation, was also examined. VPA (50 mg/kg of body weight) or diclofenac (10 mg/kg of body weight) was administered intravenously under the steady-state plasma panipenem concentration of 4 μg/ml, which had been achieved by a constant infusion rate. Panipenem decreased the plasma VPA concentrations in rats without bile duct cannulation but did not change the volume of the initial space and protein binding of VPA. However, panipenem had no effect on the plasma VPA concentrations and the biliary excretion of VPA in rats with bile duct cannulation. The secondary increase in plasma diclofenac concentration observed in the absence of panipenem was diminished in the presence of panipenem. These findings suggest that panipenem decreases plasma VPA concentrations by suppressing its enterohepatic recirculation, probably due to a panipenem-induced decrease in the numbers of enteric bacteria.     

Clinical and Epidemiological Significance of Carbapenem Resistance in Acinetobacter baumannii Infections

Carbapenems are considered the treatment of choice for Acinetobacter baumannii infections. Many facilities implement preventive measures toward only carbapenem-resistant A. baumannii (CRAB). However, the independent role of the carbapenem resistance determinant on patient outcomes remains controversial. In a 6-year analysis of adults with A. baumannii bloodstream infection (BSI), the outcomes of 149 CRAB isolates were compared to those of 91 patients with carbapenem-susceptible A. baumannii. In bivariable analyses, CRAB BSIs were significantly associated with worse outcomes and with a delay in the initiation of appropriate antimicrobial therapy (DAAT). However, in multivariable analyses, carbapenem resistance status was no longer associated with poor outcomes, while DAAT remained an independent predictor. The epidemiological significance of A. baumannii should not be determined by its resistance to carbapenems.     

The Effects of Lithium,Valproic Acid,and Carbamazepine During Pregnancy and Lactation

The chronic, complex, and episodic course of bipolar mood disorder presents a particularly formidable challenge to the clinician making a treatment plan for the onset or recurrence of the illness during pregnancy and lactation. Women treated with anti-manic drugs who become pregnant are commonly considered to be at high risk for fetal complications during the pregnancy or during lactation. The risks of antimanic drug use during pregnancy include teratogenic effects, direct neonatal toxicity, and the potential for longer-term neurobehavioral sequela. The use of medications during pregnancy and lactation requires critical attention to the timing of exposure, dosage, duration of use, and fetal susceptibility. The postnatal period is a time of increased onset and relapse of mental illness. No antimanic drug can be proven completely safe. Prescribing antimanic medications with a long safety record, avoiding exposure in the first trimester, avoiding multidrug regimens, and prescribing the lowest dose for the shortest duration will minimize the fetal risk. This review considers treatment with lithium, valproic acid, and carbamazepine. It assesses the risk to the fetus, the perinatal risks for the infant, the risks associated with treatment during the puerperium and breast-feeding, and the risks to the later development of the child.     

Interaction Between Acetohydroxamic Acid and 12 Antibiotics Against 14 Gram-Negative Pathogenic Bacteria

Acetohydroxamic acid (AHA) is a potent inhibitor of urease which prevents alkalinization of urine and stone formation in rats in the presence of infection caused by urease-producing bacteria. Because an antibacterial effect of AHA, and synergy between kanamycin and AHA have also been described, we studied the interaction between AHA and 12 antibiotics against 14 gram-negative bacteria. Synergy, sometimes to a striking degree, was found in 17% of interactions; however, antagonism was detected in 5%. Infecting organisms would need to be studied individually before the antibacterial effect of AHA and an antibiotic could be predicted.     

丙戊酸钠联合三氧化二砷诱导多发性骨髓瘤RPMI 8226细胞凋亡及其机制研究

本研究旨在探索丙戊酸钠联合三氧化二砷对多发性骨髓瘤RPMI8226细胞凋亡的影响及其相关机制.利用CCK-8法检测不同浓度的丙戊酸钠、三氧化二砷单药和两药联合应用对RPMI 8226细胞增殖的抑制作用.采用流式细胞术检测细胞凋亡情况.半定量RT-PCR和Western blot分别检测各组BCL-2、BAX、caspase-8及caspase-9的mRNA和蛋白表达水平的变化.结果表明：丙戊酸钠及三氧化二砷均可抑制RPMI 8226细胞增殖,两者联合应用有协同作用（Q值大于1.15）.联合用药组RPMI 8226细胞凋亡率较单药组明显增加（P＜0.05）.与丙戊酸钠或三氧化二砷单药组相比,联合用药组RPMI 8226细胞BCL-2 mRNA及蛋白表达水平下降,BAX、caspase-8及caspase-9mRNA及蛋白表达水平上调.结论：丙戊酸钠和三氧化二砷有协同抑制RPMI 8226细胞增殖和诱导凋亡的作用,这可能与BCL-2表达下调,BAX、caspase-8及caspase-9表达上调有关.     

Interaction of Intraleukocytic Bacteria and Antibiotics

Bacteria that survive inside polymorphonuclear neutrophils (PMN) following phagocytosis are protected from the bactericidal action of most antibiotics. Two possible explanations are altered metabolism by intraleukocytic bacteria or failure of antibiotics to enter the phagosome. The oxygen consumption of intraleukocytic and extraleukocytic bacteria was measured as an index of bacterial metabolism. PMN respiration and bactericidal activity were suppressed with large doses of hydrocortisone and extraleukocytic bacterial oxygen consumption was abolished by the addition of lysostaphin. Intraleukocytic bacterial continued to consume oxygen suggesting that surviving ingested micro-organisms are metabolically active. Neither penicillin (which cannot kill intraleukocytic bacteria) nor rifampin (which can kill intraleukocytic bacteria) was bactericidal for staphylococci at 5 degrees C. Thus, rifampin is not uniquely able to kill "resting" bacteria.Intraleukocytic or extraleukocytic Staphylococcus aurens were incubated with [benzyl-(14)C]penicillin for 2 h at 37 degrees C. Live intraleukocytic bacteria bound only 13% as much penicillin as live bacteria incubated with killed PMN. To measure the penetration of antibiotics into PMN, [(14)C]rifampin and [(14)C]penicillin were measured in leukocyte pellets and in the supernatant fluid. The total water space in the pellets was quantitated using tritium water and the extracellular water space was measured using Na(235)SO(4). All penicillin associated with the cell pellet could be accounted for in extracellular water. Thus penicillin was completely excluded from the leukocytes. Rifampin was concentrated in the cell pellet 2.2 times when compared with the supernatant concentration.These studies suggest that a likely explanation for the survival of phagocytized bacteria in the presence of high concentrations of most antibiotics is the inability of the antibiotic to enter the phagocyte. Rifampin, which is highly lipid soluble, can enter leukocytes and kill intracellular bacteria.     

Clinical Significance of In Vitro Synergism Between Antibiotics in Gram-Negative Infections

Cells of proflavine-sensitive and -resistant Escherichia coli strains were altered in different ways, and the proflavine binding of the changed material was studied. Spheroplasts prepared from sensitive and resistant cells bound similar amounts of proflavine at saturation, whether or not they were osmotically protected by 10% sucrose. Intact cells bound approximately the same amounts of proflavine as spheroplasts. On addition of glucose, osmotically protected resistant but not sensitive spheroplasts released proflavine; unprotected spheroplasts did not release bound proflavine. Thus, osmotically protected membranes are not required for proflavine binding (a passive process) but are required for proflavine release (an active process). The presence of sucrose reduced proflavine binding by resistant cells. Adding glucose to cells in 20% sucrose did not cause a release of residual proflavine, though glucose caused a release of proflavine from cells suspended in 0 or 10% sucrose. On treatment of heated cells or ruptured spheroplasts with nucleases and Pronase, practically all nucleic acids were removed. Proflavine-binding ability of such preparations fell by only 30 to 50%. Washing heated cells with ethanol did not reduce their proflavine-binding ability. There appear to be important binding sites in cells aside from nucleic acids.     

孕妇血清总胆汁酸测定的临床意义

目的 了解正常孕妇和妊娠期肝内胆汁淤积症（ICP）患者血清总胆汁酸水平。方法 检测ICP组、妊娠高血压疾病组（PIH）、正常孕妇以及正常未孕女性及男性组血清总胆汁酸（TBA）的水平,同时对ICP组其他肝功能相关指标也进行检测。结果 ICP组TBA水平较其他3组明显增高,而其他3组之间差异无显著性。ICP孕妇TBA与血清碱性磷酸酶（ALP）、γ-谷氨酰转肽酶（GGT）、直接胆红素（DBIL）的检测水平有良好的相关性;且TBA在灵敏度和特异性上均优于以上指标。结论 血清总胆汁酸的测定对孕妇胆汁淤积症的诊断、疗效评估以及预后判断均具有重要意义。     

氟达拉滨联合丙戊酸对慢性粒细胞白血病细胞凋亡诱导作用

目的 研究氟达拉滨（Fludarabine,FDB）联合丙戊酸（valproic acid,VPA）对慢性粒细胞白血病（chronic myeloidleukemia,CML）细胞株K562增殖及凋亡的影响,并探讨其可能的作用机制.方法 慢性粒细胞白血病细胞株K562,单独使用不同浓度的FDB（1,5,10μmol/L）或VPA（1,2.5,5 mmol/L）,或联合使用FDB和VPA处理K562细胞,采用MTT法检测细胞增殖情况,并观察其有效的作用浓度;流式细胞仪检测K562细胞周期变化;western blot检测凋亡相关蛋白及组织蛋白酶B的表达变化.结果 单独使用FDB或VPA均可明显抑制K562细胞的增殖,呈剂量依赖性,并使K562细胞停滞在G0/G1期,联合使用VPA能增强FDB对K562细胞的凋亡诱导作用.同时检测到FDB和VPA能诱导溶酶体中组织蛋白酶B的表达.结论 联合使用FDB和VPA可诱导K562细胞溶酶体中组织蛋白酶B的表达及活性,从而启动溶酶体介导的细胞凋亡过程,明显抑制K562细胞的增殖,并促进K562细胞的凋亡,提高治疗效果,为临床抗肿瘤治疗提供新的指导方向.