Efficacy of quinupristin-dalfopristin against methicillin-resistant Staphylococcus aureus and vancomycin-insensitive S. aureus in a model of hematogenous pulmonary infection

BACKGROUND: Quinupristin-dalfopristin (Q-D) is a mixture of quinupristin and dalfopristin, which are semisynthetic antibiotics of streptogramin groups B and A, respectively. METHODS: We compared the effect of Q-D to that of vancomycin (VCM) in murine models of hematogenous pulmonary infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and VCM-insensitive S. aureus (VISA). RESULTS: Treatment with Q-D resulted in a significant decrease in the number of viable bacteria in the lungs of mice in an MRSA infection model [Q-D 100 mg/kg, Q-D 10 mg/kg, VCM and control (mean +/- SEM): 2.99 +/- 0.44, 6.38 +/- 0.32, 5.75 +/- 0.43 and 8.40 +/- 0.14 log10 CFU/lung, respectively]. Compared with VCM, high-dose Q-D significantly reduced the number of bacteria detected in the VISA hematogenous infection model [Q-D 100 mg/kg, Q-D 10 mg/kg, VCM and control (mean +/- SEM): 5.17 +/- 0.52, 7.03 +/- 0.11, 7.10 +/- 0.49 and 7.18 +/- 0.36 log10 CFU/lung, respectively]. Histopathological examination confirmed the effect of Q-D. CONCLUSION: Our results suggest that Q-D is potent and effective in the treatment of MRSA and VISA hematogenous pulmonary infections.     

Potency of SMP-601, a novel carbapenem, in hematogenous murine bronchopneumonia caused by methicillin-resistant and vancomycin-intermediate Staphylococcus aureus

We compared the potency of SMP-601, a novel carbapenem, with that of vancomycin in a murine model of hematogenous bronchopneumonia infection caused by methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-intermediate S. aureus (VISA). The MICs of SMP-601 and vancomycin against MRSA were 2 and 1 mug/ml, respectively, while those against VISA were 2 and 8 mug/ml, respectively. Treatment with SMP-601 resulted in a significant decrease in the number of viable bacteria in the MRSA infection model (control, 100 mg/kg vancomycin, and 100 mg/kg SMP-601, 8.42 +/- 0.50, 5.29 +/- 0.71, and 5.50 +/- 0.58 log CFU/lung, respectively,) and in the VISA infection model (control, 100 mg/kg vancomycin, and 100 mg/kg SMP-601, 9.64 +/- 0.63, 8.72 +/- 0.45, 7.42 +/- 0.14 log CFU/lung) (mean +/- standard error of the mean). The survival rate in the VISA infection model treated with SMP-601 (70%) was significantly higher than those in the other two groups (20% for vancomycin and 0% for control; P < 0.05). Histopathological examination revealed that inflammatory changes in the SMP-601-treated group were less marked than in the other two groups. The results of pharmacokinetic-pharmacodynamic analysis supported the results of the bacteriological, histopathological and survival studies. Our results demonstrate the potency of SMP-601 against MRSA and VISA in murine hematogenous pulmonary infection.     

Methicillin-resistant Staphylococcus aureus (MRSA) isolated in hospitals in Fukuoka City area]

Bacteriological and clinical studies were carried out on 280 strains of Staphylococcus aureus isolated in hospitals in Fukuoka city area from September 1990 to March 1991. Of all S. aureus strains studied 116 (41.4%) were methicillin-resistant. The proportion of MRSA in S. aureus isolates from outpatients was 10% (11/109), 69.2% (90/130) in those from inpatients. The average age of patients with isolated MRSA was 70.5 +/- 16.9 years and that of patients with isolated MSSA, 44.2 +/- 29.3. MRSA strains were recovered mainly from sputum and pus. The isolation rate did not vary significantly with hospitals of different size (number of beds). Of all MRSA strains 48 (41.3%) produced coagulase type VII. As for drug susceptibility, MRSA strains with coagulase type VII were more sensitive to clindamycin and more resistant to minocyclin compared to MRSA with other coagulase types.     

siRNA逆转K562/A02细胞多药耐药的研究

目的　研究小分子干扰RNA片段 (smallinterferingRNAs,siRNA)对白血病多药耐药细胞系K5 6 2 A0 2mdr1基因和P 糖蛋白 (P gp)表达及功能的影响。方法　根据mdr1基因已知序列设计 3条含 2 1个碱基的siRNA(si mdr1 1,si mdr1 2 ,si mdr1 3)及阴性对照 (si neg) ,在脂质体的介导下转染K5 6 2 A0 2细胞 ;用RT PCR分析mdr1mRNA的表达 ;流式细胞术检测P gp表达和细胞内柔红霉素积累量 ;MTT法检测阿霉素对K5 6 2 A0 2细胞的半数抑制浓度 (IC50 )。结果　 3条siRNA均能不同程度地逆转K5 6 2 A0 2细胞的多药耐药。第 3条序列能更有效地封闭mdr1基因 ,使mdr1mRNA相对水平下降(5 8.0± 1 5 4 ) % ;P gp表达由处理前的 (76 .0± 1.0 ) %降到处理后的 (19.6± 1.9) % ;对阿霉素药物敏感性的相对逆转效率为 70 .4 % ;同时使K5 6 2 A0 2细胞内柔红霉素积累量增加。结论　siRNA可逆转mdr1基因编码蛋白P gp介导的多药耐药。     

机械通气相关肺部感染的病原菌调查及耐药性分析

目的调查重症监护病房（ICU）机械通气相关肺部感染的病原菌并分析其耐药性。方法对2006～2007年ICU62例机械通气相关肺部感染患者的下呼吸道标本分离出的致病菌进行鉴定及药敏试验。结果共检出致病菌89株,其中革兰阴性菌占74．2％（66株）,革兰阳性菌占19．1％（17株）,念珠菌占6．7％（6株）。检出耐甲氧西林金黄色葡萄球菌10株（83．3％）,产超广谱肛内酰胺酶菌9株（42．9％）。结论ICU使用呼吸机易引起医院内肺部感染,感染的病原菌以铜绿假单胞菌和金黄色葡萄球菌为主。药敏结果显示细菌的耐药情况严重,应引起重视。     

老年细菌性阴道炎患者致病菌分布与耐药性调查与分析

目的 分析老年细菌性阴道炎患者致病菌分布及耐药现状,为临床治疗提供依据.方法 回顾性分析2008～2010年于本院确诊的老年细菌性阴道炎患者送检的阴道分泌物标本致病菌分离、培养、鉴定及药敏试验结果.结果 主要病原菌依次为凝固酶阴性葡萄球菌(26.2%)、金黄色葡萄球菌(22.8%)、大肠埃希菌(20.5%)、肺炎克雷伯菌(14.7%)和屎肠球菌(12.1%).耐甲氧西林金黄色葡萄球菌(MRSA)和耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)检出率分别为46.8%、35.2%;超广谱β内酰胺酶(ESBLs)阳性大肠埃希菌和肺炎克雷伯菌分别为23.9%、23.5%.葡萄球菌对青霉素、红霉素耐药率较高,屎肠球菌对青霉素耐药率相对较低;MRSA、MRCNS及ESBLs阳性大肠埃希菌和肺炎克雷伯菌多药耐药现象严重.结论 革兰阳性球菌为老年细菌性阴道炎主要致病菌,其中肠球菌耐药性较轻,革兰阴性杆菌检出率相对较低.     

Efficacy of telavancin in a murine model of bacteraemia induced by methicillin-resistant Staphylococcus aureus

OBJECTIVES: The efficacy of telavancin, a bactericidal lipoglycopeptide, was compared with vancomycin against methicillin-resistant Staphylococcus aureus (MRSA) in an immunocompromised murine model of bacteraemia. METHODS: Immunocompromised mice were inoculated intraperitoneally with S. aureus ATCC 33591 and treated with two subcutaneous doses (once every 12 h) of vehicle or test compound. Mouse pharmacokinetic data were generated and used to choose doses of telavancin (40 mg/kg) and vancomycin (110 mg/kg) in order to equate clinical exposures. Reduction in bacterial titre (in blood and spleen) and mortality were the two pharmacodynamic endpoints of the study. RESULTS: Mortality was 100% in animals treated with vehicle or vancomycin but was significantly lower (7%) in telavancin-treated animals. Telavancin produced significantly greater reductions in blood and spleen bacterial titres compared with vancomycin. CONCLUSIONS: The data described here demonstrate that telavancin's in vivo bactericidal activity is superior to that of vancomycin against a single strain of MRSA and results in successful infection resolution and, consequently, improved survival in the murine bacteraemia model.     

细胞内氯通道4基因siRNA表达载体的构建及其沉默效应

目的构建针对细胞内氯通道4（CLICA）的短链干涉RNA（siRNA）及其表达载体,转染细胞后观察其对CLIC4基因的干涉作用。方法设计CLICA靶向的发夹状siRNA,据此设计合成两条互补的寡核苷酸链,退火后连接到pSilencer3．1-H1载体,转化扩增后进行序列测定。用脂质体转染法转染大鼠神经胶质瘤细胞C6,通过RT-PCR检测CLICA基因表达水平的变化。结果酶切鉴定与DNA测序分析证明CLICA基因的siRNA载体构建正确,RT-PCR结果表明CLICA基因的表达水平明显降低。结论成功地构建了针对CLICA基因的siRNA载体,转染细胞后可显著抑制CLICA基因表达。     

临床分离主要细菌耐药监测结果统计分析

目的统计分析宜昌市中心人民医院2009年临床分离主要细菌耐药情况。方法细菌鉴定采用法国生物梅里埃API系统鉴定。药敏试验采用K-B法,抗菌谱遵照美国临床实验室标准化协会(CLSI)M100-S18指南。药敏结果以WHONET5.4软件进行统计分析。结果 2009年细菌室从临床共分离菌株1835株,其中革兰阴性杆菌占55.68%,革兰阳性球菌占34.05%,真菌占10.27%。大肠埃希菌和克雷伯菌属的超广谱β-内酰胺酶(ESBLs)产生率分别为68.2%和59.4%。耐甲氧西林金黄色葡萄球菌(MRSA)和耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)分别占金黄色葡萄球菌(MSSA)和凝固酶阴性葡萄球菌的60.4%和65.8%。屎肠球菌的耐药率高于粪肠球菌,但分离率低于粪肠球菌。氨基糖苷类对高度耐药肠球菌的产生率为58.1%。结论宜昌市中心人民医院产ESBLs的大肠埃希菌和克雷伯菌、MRSA、MRCNS的检出率较高,特别是泛耐药的鲍曼不动杆菌的耐药率明显高于国内其他医院,应引起重视。     

靶向X区的siRNA抑制乙型肝炎病毒基因的表达和复制

目的构建针对乙型肝炎病毒（HBV）X基因的siRNA表达载体，观察其对HBV基因表达和复制的影响。方法设计并合成针对HBVX区基因的siRNA寡核苷酸，经退火形成双链后克隆人pSUPER载体，构建成功的siRNA表达载体与pTK-Hyg质粒共转染稳定表达HBV的HepG22．2．15细胞，潮霉素抗性筛选获得稳定细胞克隆，对所得细胞培养上清液中的HBsAg和HBeAg进行定量检测，逆转录-聚合酶链反应（RT-PCR）检测靶基因mRNA的抑制效果，荧光定量PCR检测HBVDNA。结果成功构建了针对HBVX基因的siRNA表达载体pSUPER-X1和pSUPER-X2，两种siRNA均能明显抑制HepG22．2．15细胞的HBsAg和HBeAg分泌，抑制率分别为97％和88％，RT-PCR结果显示HBV的mRNA表达降低，荧光定量PCR结果证实siRNA能降低HBVDNA拷贝数2个数量级。结论载体产生的针对HBVX基因的siRNA能高效、特异地抑制HBV基因的表达和复制。     

Virulence factor expression by Gram-positive cocci exposed to subinhibitory concentrations of linezolid

Linezolid is a new oxazolidinone with potent antibacterial activity against Gram-positive cocci; it uniquely inhibits bacterial translation through inhibition of 70S initiation complex formation. The effects of sub-growth-inhibitory concentrations of linezolid on the expression of various structural and soluble virulence factors of Staphylococcus aureus and Streptococcus pyogenes were examined. For S. aureus, strains Wood 46 and Cowan 1 (NCTC 8532) were used to measure protein A, coagulase, alpha-haemolysin (hla) and delta-haemolysin (hld). For S. pyogenes, strain NCTC 9994 was used to measure M protein, streptolysin O (SLO) and DNase. Coagulase was assayed by clotting of citrated rabbit plasma, and hla, hld and SLO by lysis of rabbit, human and horse erythrocytes, respectively. Protein A and M protein were measured indirectly using bacterial susceptibility to phagocytic ingestion of radiolabelled bacteria by human neutrophils. When S. aureus was grown in 1/2, 1/4 and 1/8 MIC, linezolid, coagulase, hla and hld production were impaired. Susceptibility to phagocytosis was changed by growth in the presence of 1/2 MIC linezolid compared with that in its absence (50.8 +/- 4.1% versus 38.9 +/- 2.9%; P 相似文献   

Effects of DQ-113, a new quinolone, against methicillin- and vancomycin-resistant Staphylococcus aureus-caused hematogenous pulmonary infections in mice

We compared the effects of DQ-113, a new quinolone, to those of vancomycin (VCM) and teicoplanin (TEIC) in murine models of hematogenous pulmonary infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and VCM-insensitive S. aureus (VISA). The MICs of DQ-113, VCM, and TEIC for MRSA were 0.125, 1.0, and 0.5 microg/ml, respectively; and those for VISA were 0.25, 8.0, and 8.0 microg/ml, respectively. Treatment with DQ-113 resulted in a significant decrease in the number of viable bacteria in the lungs of the mice used in the MRSA infection model (counts in mice treated with DQ-113, VCM, and TEIC and control mice, 6.33 +/- 0.22, 7.99 +/- 0.14, 7.36 +/- 0.20, and 8.47 +/- 0.22 log10 CFU/lung [mean +/- standard error of the mean], respectively [P<0.01 for the group treated with DQ-113 compared with the group treated with VCM or TEIC or the untreated group]). Mice infected with VISA were pretreated with cyclophosphamide, and the survival rate was recorded daily for 10 days. At the end of this period, 90% of the DQ-113-treated mice were still alive, whereas only 45 to 55% of the mice in the other three groups were still alive (P<0.05 for the group treated with DQ-113 compared with the group treated with VCM or TEIC or the untreated group]). DQ-113 also significantly (P<0.05) reduced the number of viable bacteria in the lungs compared with those in the lungs of the other three groups (counts in mice treated with DQ-113, VCM, and TEIC and control mice, 5.76 +/- 0.39, 7.33 +/- 0.07, 6.90 +/- 0.21, and 7.44 +/- 0.17 log10 CFU/lung, respectively). Histopathological examination revealed milder inflammatory changes in DQ-113-treated mice than in the mice in the other groups. Of the antibiotics analyzed, the parameters of area under the concentration-time from 0 to 6 h (AUC(0-6))/MIC and the time that the AUC(0-6) exceeded the MIC were the highest for DQ-113. Our results suggest that DQ-113 is potent and effective for the treatment of hematogenous pulmonary infections caused by MRSA and VISA strains.     

铜陵市部分医院细菌耐药性监测与分析

目的了解安徽省铜陵市临床分离菌株耐药状况。方法2007年1～12月铜陵市临床分离菌株用Kirby-Bauer法进行药敏试验。结果1375株细菌中,革兰阳性菌399株,占29．0％;革兰阴性菌976株,占71．0％。耐甲氧西林金黄色葡萄球菌（MRSA）和耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）分别占金黄色葡萄球菌和凝固酶阴性葡萄球菌（CNS）的18．4％和70．0％;MRSA和MRCNS对庆大霉素、环丙沙星、克林霉素和红霉素等均高度耐药,对利福平、氯霉素和呋喃妥因的耐药率均较低,未见耐万古霉素葡萄球菌。粪肠球菌对青霉素、氨苄西林、呋喃妥因、磷霉素和氯霉素的耐药率较低,未见耐万古霉素和替考拉宁粪肠球菌;屎肠球菌对磷霉素和氯霉素耐药率较低,发现2株耐万古霉素屎肠球菌。大肠埃希菌和克雷伯菌属中产超广谱β-内酰胺酶（ESBLs）株分别占49．3％和35．9％,产ESBLs株除对亚胺培南和美罗培南敏感外,对其他20种抗生素的耐药率均较不产ESBLs株高。非发酵菌对碳青霉烯类、头孢哌酮／舒巴坦、哌拉西林／三唑巴坦、头孢他啶、头孢吡肟、阿米卡星、环丙沙星等耐药率较低。结论革兰阳性菌对糖肽类抗生素耐药率低;革兰阴性菌对碳青霉烯类、头孢哌酮／舒巴坦、哌拉西林／三唑巴坦等耐药率低。加强细菌耐药性监测对合理使用抗生素、减少耐药菌株的产生和流行有重要临床指导价值。     

临床感染病原菌的分布及耐药性监测

目的 研究临床感染病原菌的分布，揭示感染特征及流行病学规律，为感染性疾病的诊疗提供依据。方法对我院临床感染患者标本中分离的5514株病原菌进行鉴定，监测常见分离菌的耐药菌株(MDR)。结果5514株分离菌以G^-杆菌为主(56．5％)，其次为G^ 球菌(26．1％)和酵母样菌(16．6％)；分布占前十位的细菌为：凝固酶阴性的葡萄球菌、大肠埃希菌、铜绿假单胞菌、肺炎克雷伯菌、鲍曼不动杆菌、金黄色葡萄球菌、阴沟肠杆菌、肠球菌、嗜麦芽窄食假单胞菌、肺炎链球菌。大肠埃希菌、肺炎克雷伯菌中产生广谱β-内酰胺酶(ESBLs)株分别是25．4％、20．5％。耐甲氧西林金黄色葡萄球菌(MRSA)和耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)分别占金黄色葡萄球菌和凝固酶阴性葡萄球菌的65．4％、78.8％，无万古霉素耐药株；氨基糖苷类高水平耐药(HLAR)肠球菌检出率为63．1％，耐万古霉素肠球菌(VRE)占5．8％。结论正常菌群、条件致病菌是现代医院感染的主要病原菌。耐药菌株的不断出现和对抗生素多重耐药是目前临床上的严重问题。临床上应合理使用抗生素。减少耐药菌株的产生及播散。     

Improved oxacillin treatment outcomes in experimental skin and lung infection by a methicillin-resistant Staphylococcus aureus isolate with a vraSR operon deletion

Methicillin-resistant Staphylococcus aureus (MRSA) strains are major pathogens causing infections of the skin and soft tissues and more serious, life-threatening diseases, including sepsis and necrotizing pneumonia. The vraSR operon encodes the key regulatory system that modulates the stress response of S. aureus elicited upon exposure to cell wall antibiotics. Mutation of vraS and vraR results in decreased oxacillin resistance in vitro. We investigated the effect of oxacillin treatment in experimental models employing a clinical USA300 MRSA strain (strain 923) and an isogenic vraSR deletion mutant (strain 923-M23). In a murine model of S. aureus necrotizing pneumonia, animals were treated with oxacillin, beginning 15 min after inoculation. Among mice infected with mutant strain 923-M23, oxacillin treatment significantly improved survival compared with saline treatment, whereas oxacillin treatment had no effect in mice infected with strain 923. Similarly, treatment with oxacillin decreased the bacterial burden among animals infected with strain 923-M23 but not among animals infected with strain 923. In a murine skin infection model, oxacillin eliminated the development of dermonecrosis among 923-M23-infected mice and decreased the bacterial burden in the lesions, but not among strain 923-infected mice. We conclude that deletion of the vraSR operon allowed an oxacillin regimen to be effective in murine models of MRSA pneumonia and skin infection. These findings provide proof-of-principle for development of a new antibiotic that could restore the usefulness of oxacillin against MRSA by inhibiting VraS or VraR.     

The MUT056399 inhibitor of FabI is a new antistaphylococcal compound

MUT056399 is a highly potent new inhibitor of the FabI enzyme of both Staphylococcus aureus and Escherichia coli. In vitro, MUT056399 was very active against S. aureus strains, including methicillin-susceptible S. aureus (MSSA), methicillin-resistant S. aureus (MRSA), linezolid-resistant, and multidrug-resistant strains, with MIC(90)s between 0.03 and 0.12 μg/ml. MUT056399 was also active against coagulase-negative staphylococci, with MIC(90)s between 0.12 and 4 μg/ml. The antibacterial spectrum is consistent with specific FabI inhibition with no activity against bacteria using FabK but activity against FabI-containing Gram-negative bacilli. In vitro, resistant clones of S. aureus were obtained at a low frequency. All of the resistant clones analyzed were found to contain mutations in the fabI gene. In vivo, MUT056399, administered subcutaneously, protected mice from a lethal systemic infection induced by MSSA, MRSA, and vancomycin-intermediate S. aureus strains (50% effective doses ranging from 19.3 mg/kg/day to 49.6 mg/kg/day). In the nonneutropenic murine thigh infection model, the same treatment with MUT056399 reduced the bacterial multiplication of MSSA and MRSA in the thighs of immunocompetent mice. These properties support MUT056399 as a very promising candidate for a novel drug to treat severe staphylococcal infections.     

Cutaneous community-acquired methicillin-resistant Staphylococcus aureus infection in participants of athletic activities

OBJECTIVES: Cutaneous community-acquired methicillin-resistant Staphylococcus aureus (CAMRSA) has been identified in otherwise healthy individuals either with or without methicillin-resistant S. aureus (MRSA)-associated risk factors who participate in athletic activities. The purpose of this study was to describe the clinical features of CAMRSA skin infection that occurred in university student athletes, evaluate the potential mechanisms for the transmission of MRSA infection of the skin in participants of athletic activities, and review the measures for preventing the spread of cutaneous CAMRSA infection in athletes. METHODS: A retrospective chart review of the student athletes from the University of Houston whose skin lesions were evaluated at the Health Center and grew MRSA was performed. The clinical characteristics and the postulated mechanisms of cutaneous MRSA infection in the athletes were compared with those previously published in reports of CAMRSA skin infection outbreaks in other sports participants. RESULTS: Cutaneous CAMRSA infection occurred in seven student athletes (four women and three men) who were either weight lifters (three students) or members of a varsity sports team: volleyball (two women), basketball (one woman), and football (one man). The MRSA skin infection presented as solitary or multiple, tender, erythematous, fluctuant abscesses with surrounding cellulitis. The lesions were most frequently located in the axillary region (three weight lifters), on the buttocks (two women), or on the thighs (two women). The drainage from all of the skin lesions grew MRSA, which was susceptible to clindamycin, gentamicin, rifampin, trimethoprim/sulfamethoxazole, and vancomycin; five of the isolates were also susceptible to ciprofloxacin and levofloxacin. All of the bacterial strains were resistant to erythromycin, oxacillin, and penicillin. The cutaneous MRSA infections persisted or worsened in the six athletes who were empirically treated for methicillin-sensitive S. aureus at their initial visit. Complete resolution of the skin infection occurred after the abscesses had been drained and the athlete had been treated with systemic antimicrobial therapy for which the bacterial strain was susceptible. CONCLUSIONS: Cutaneous CAMRSA infection typically presents as an abscess, with or without surrounding cellulitis, in otherwise healthy participants of athletic activities who have or do not have MRSA-associated risk factors. Athletes who have MRSA skin infections include weight lifters and team members from competitive sports such as basketball, fencing, football, rugby, volleyball, and wrestling. Bacterial culture of suspected infectious skin lesions should be performed to establish the diagnosis of cutaneous MRSA infection and to determine the antibiotic susceptibility of the bacterial isolate. Treatment of cutaneous MRSA infection involves drainage of the abscess (either spontaneously or after incision) and appropriate systemic antimicrobial therapy. Direct skin-to-skin physical contact with infectious lesions or drainage, skin damage that facilitates the entry of bacteria, and sharing of infected equipment, clothing, or personal items may result in the acquisition and transmission of MRSA infection in participants of athletic activities. Earlier detection and topical treatment of the athlete's skin wounds by their coaches, avoidance of contact with other participants' cutaneous lesions and their drainage, and good personal hygiene are measures that can potentially prevent the spread of cutaneous MRSA infection in participants of athletic activities.     

4380株医院感染病原菌的临床分布及耐药性分析

目的了解4 380株医院感染病原菌的临床分布及其耐药性。方法对重庆市急救医疗中心住院患者的标本按常规进行病原菌分离、鉴定和抗菌药物敏感性试验,结果用WHONET5.6软件进行分析。结果医院感染检出率前5位的科室为神经外科、神经内科、创伤科、肿瘤科和中心重症监护病房;7 326例临床送检标本中,分离到4 380株病原菌,检出率约为59.8%,其中革兰阴性杆菌占75.3%(3 300/4 380),革兰阳性球菌占19.0%(831/4 380),真菌占5.7%(249/4 380),排名前10位病原菌依次为:铜绿假单胞菌、肺炎克雷伯菌、鲍曼不动杆菌、大肠埃希菌、白色念珠菌、凝固酶阴性葡萄球菌、金黄色葡萄球菌、肠球菌属、阴沟肠杆菌、洛菲不动杆菌。耐甲氧西林金黄色葡萄球菌(MRSA)检出率为49.1%,耐甲氧西林凝固酶阴性葡萄球菌(MRCNS)检出率为81.2%,均未检出对糖肽类耐药的葡萄球菌,产超广谱β-内酰胺酶(ESBLs)阳性的大肠埃希菌检出率为58.9%,ESBLs阳性肺炎克雷伯菌检出率为28.9%。结论多种因素致患者免疫力低下,是条件致病菌引起医院感染的主要原因;病原菌以革兰阴性杆菌为主,其中铜绿假单胞菌上升尤为明显,真菌感染比例也有明显上升趋势。肠杆菌科细菌对碳青霉烯酶类、阿米卡星和哌拉西林/他唑巴坦等抗菌药物耐药率较低,铜绿假单胞菌和鲍曼不动杆菌呈现多重耐药趋势。     

导入针对survivin基因的siRNA对大肠癌Lovo细胞凋亡和增殖的影响

目的：向大肠癌离体LOVO细胞中导入针对survivin基因的siRNA，并研究其对LOVO细胞凋亡的影响。方法：设计2条特异性针对survivin基因的siRNA，并体外转录法合成，利用脂质体导入LOVO细胞并检测转染后细胞的凋亡和增殖情况。结果：RTPCR检测survivin mRNA表达水平发现两RNA干扰组细胞内survivin mRNA表达量明显低于正常LOVO细胞；细胞凋亡检测结果发现两干扰组细胞凋亡率分别为21、5％和26、28％明显高于正常Lovo细胞；细胞增殖结果显示：两干扰组细胞增殖能力比正常Lovo细胞减弱。结论：针对survivin基因的siRNA能有效降低目的基因的mRNA表达，抑制LOVO细胞生长，细胞凋亡率明显增高。为大肠癌基因治疗的可行性提供了有力的证据。     

安徽省铜陵地区2008年细菌耐药性监测

目的了解安徽省铜陵地区临床分离菌株耐药状况。方法2008年1—12月铜陵地区临床分离菌株用Kirby-Bauer法进行药敏试验。结果1 476株细菌中革兰阳性菌408株占27.6%;革兰阴性菌1 068株占72.4%;MRSA和MRCNS分别占金葡菌和CNS的24.1%和62.9%;MRSA和MRCNS对庆大霉素、环丙沙星、克林霉素和红霉素等均高度耐药,对利福平和氯霉素的耐药率均较低;未见耐万古霉素葡萄球菌;粪肠球菌对青霉素、氨苄西林、呋喃妥因、磷霉素和氯霉素的耐药率较低,未见耐万古霉素和替考拉宁粪肠球菌;屎肠球菌对磷霉素和氯霉素耐药率较低,发现1株万古霉素耐药屎肠球菌。大肠埃希菌和克雷伯菌属中产ESBLs株分别占49.3%和30.9%,产ESBLs株除对亚胺培南和美罗培南均无耐药外,对其他19种抗菌药物的耐药率均较非产ESBLs株高;不发酵糖菌对亚胺培南、美罗培南和头孢哌酮-舒巴坦等耐药率较低。结论革兰阳性菌对糖肽类抗菌药物耐药率低;肠杆菌科细菌对亚胺培南、美罗培南、头孢哌酮-舒巴坦、哌拉西林-他唑巴坦和阿米卡星等耐药率低。