院内不同时间段铜绿假单胞菌的耐药性分析

目的：分析本院内不同时间段分离的铜绿假单胞菌对各种抗菌药物的耐药性变化,为临床合理使用抗菌药物提供依据。方法对2012年10月至2012年12月（2012年第4季度）分离的142株铜绿假单胞菌、2013年1月至2013年3月（2013年第1季度）分离的129株铜绿假单胞菌、2013年4月至2013年6月（2013年第2季度）分离的74株铜绿假单胞菌、2013年7月至2013年9月（2013年第3季度）分离的140株铜绿假单胞菌,用WalkAway 96 PLUS NC50药敏板检测菌株对亚胺培南等12种抗菌药物的耐药性,并对检测结果分别进行分析。结果2012年第4季度分离的142株铜绿假单胞菌对替卡西林/克拉维酸、氨曲南和亚胺培南的耐药率分别为35.2%（50/140）、31.0%（44/142）和30.3%（43/142）,对哌拉西林、左旋氧氟沙星、环丙沙星、哌拉西林/他唑巴坦、头孢他啶、妥布霉素、庆大霉素、头孢吡肟和阿米卡星的耐药率为9.2%～26.8%。2013年第1季度分离的129株铜绿假单胞菌对替卡西林/克拉维酸、氨曲南、亚胺培南、左旋氧氟沙星为33.3%～44.4%,对环丙沙星、哌拉西林、头孢他啶、头孢吡肟、哌拉西林/他唑巴坦、庆大霉素、妥布霉素和阿米卡星的耐药率为9.3%～27.9%。2013年第2季度分离的74株铜绿假单胞菌对亚胺培南、替卡西林/克拉维酸、氨曲南、环丙沙星、左旋氧氟沙星和哌拉西林的耐药率为32.8%～47.3%,对妥布霉素、庆大霉素、头孢他啶、头孢吡肟、哌拉西林/他唑巴坦和阿米卡星的耐药率为17.6%～27.0%。2013年第三季度分离的140株铜绿假单胞菌以上12种抗菌药物的耐药率为2.9%～26.4%。不同阶段分离的菌株80%以上都来自痰液。结论院内不同季度分离的铜绿假单胞菌对临床常用抗菌药物的耐药率都存在一定的差异,2013年第1季度和第2季度分离的铜绿假单胞菌的耐药性显著高于2013年第3季度和2012年第4季度分离的铜?     

烧伤创面铜绿假单胞菌的分离和耐药谱分析

目的　探讨烧伤创面铜绿假单胞菌耐药谱的变迁及诱导型 β 内酰胺酶的产生。 方法对笔者医院 1996年 6月～ 2 0 0 0年 6月鉴定的 4 5 2株烧伤创面铜绿假单胞菌 ,用VITEK AMS全自动细菌鉴定及药敏系统、E test浓度梯度法做药敏试验 ,以K B法为基础作诱导酶的检测。　结果　 4年中临床常用的头孢菌素及亚胺培南的耐药率均有提高 ;其中以头孢哌酮 /舒巴坦的耐药率最低 ,但 4年中耐药率的变化差异也有显著性意义 (P <0 .0 5 ) ,亚胺培南的耐药率在 2 0 %～ 4 0 %之间。 12 0株野生型铜绿假单胞菌中 ,以亚胺培南为诱导剂 ,检出产生诱导酶者为 72 .5 %。　结论　烧伤创面铜绿假单胞菌耐药谱的分析和诱导酶的检测 ,可以及时监控和调整抗生素的使用 ,对避免铜绿假单胞菌在医院内流行具有重要意义     

ICU铜绿假单胞菌耐药性调查

铜绿假单胞菌是医院感染的主要病原菌 ,该菌具有天然耐药性 ,增长迅速。为动态观察该菌的耐药性 ,2 0 0 0年 1月至 2 0 0 2年 2月采集ＩＣＵ病人呼吸道分离的 2 33株标本进行了耐药性调查。1　方法1 1　标本留取方法指导病人清晨先用朵贝尔液漱口 ,再用清水漱口后 ,用力咳出气管深处痰液入无菌培养盒中 (避免混入唾液及鼻腔分泌物 )送检。1 2　试验方法细菌鉴定用常规法 ,药敏试验采用纸片扩散法[1] 。纸片选择、试验方法、质量控制与判定标准按美国 1999年颁布的临床实验室标准委员会 (ＮＣ ＣＬＳ)标准。所用 14种药敏纸片是 :复方新诺明…     

铜绿假单胞菌感染在临床上耐药性的分析

目的:了解铜绿假单胞菌感染在临床上的耐药性及临床分布特点,为临床合理使用抗生素提供理论依据.方法:从本院各科室收集的标本中分离出98株铜绿假单胞菌,同时进行抗生素敏感试验.结果:铜绿假单胞菌在15种临床常用抗生素中,表现为多重耐药,其中3种抗生素的耐药率达到80％以上,而临床上以呼吸道感染为主,在各科室分布中以重症监护病房最高.结论:加强对呼吸道患者的防护,合理使用抗生素,对感染患者采取积极的防治措施,最大限度地降低铜绿假单胞菌的感染.     

烧伤病房铜绿假单胞菌耐药率及抗菌药使用变化

目的 了解烧伤病房铜绿假单胞菌耐药率和抗菌药物使用变化,为合理应用抗菌药物、缓解铜绿假单胞菌耐药程度提供依据.方法 采集2005年1月-2009年12月笔者单位5717例住院患者创面、导管、血液、大便、尿液、痰液标本,行细菌培养.计算各年标本送检率与细菌检出情况.分析5年间球菌与杆菌菌株数之比、细菌分布情况、铜绿假单胞菌耐药率、抗菌药物使用强度,对细菌耐药率和抗菌药物使用强度行相关分析.用WHONET 5.4软件处理细菌一般情况及铜绿假单胞菌耐药率数据,对其他数据行x2检验与Bivariate相关分析.结果 (1)5年间标本送检率差异无统计学意义(73.2%～76.1%,x2=5.583,P＞0.05).送检的各类标本共检出菌株1675株,细菌检出比例呈逐年增加趋势.菌株来源:创面1434株、导管39株、血液29株、大便3株、尿液13株、痰液157株.5年间球菌、杆菌菌株数之比差异有统计学意义(105:134～181:126,x2=14.806,P＜0.01).(2)各年主要检出细菌是金黄色葡萄球菌(占28%～42%)、铜绿假单胞菌(占10%～25%)及鲍氏不动杆菌(占10%～19%).(3)5年间,铜绿假单胞菌对12种抗菌药物耐药率差异均有统计学意义(x2值为47.911～308.095,P值均小于0.01),其中对阿米卡星、头孢他啶、亚胺培南/西司他丁的耐药率前4年呈下降趋势,第5年有所反弹.(4)头孢哌酮/舒巴坦与左氧氟沙星的使用强度呈降低趋势;万古霉素的使用强度始终处于前列,呈逐渐上升趋势.(5)铜绿假单胞菌对阿米卡星、亚胺培南/西司他丁、环丙沙星等7种抗菌药物的耐药率与多种抗菌药物使用强度呈显著正相关(r值为0.879～0.978,P＜0.05或P＜0.01).结论 笔者单位铜绿假单胞菌的耐药情况比较严重,与抗菌药物使用强度相关,需要通过严格掌握抗菌药物使用指征、策略性更换使用抗菌药物、联合用药、严格执行消毒隔离措施等综合手段来缓解.

Abstract：

Objective To study changes in the drug-resistance of Pseudomonas aeruginosa (PA)and the use of antibiotics in burn wards so as to optimize the use of antibiotic in the future. Methods Bacteria were isolated from specimens of blood, venous catheter, stool, sputum, urine, wound tissue from 5717 patients hospitalized in our burn wards within the duration of January 2005 to December 2009. The number of specimens examined and positive rates of bacteria were calculated. Changes in constituent ratio of cocci and bacilli, spectrum of bacteria, the drug-resistance rate of PA, and the usage of antibiotics were analyzed. The number of specimens examined, constituent ratio of cocci and bacilli, drug-resistance rate were processed with chi-square test. Bivariate correlation analysis was performed between the usage of antibiotics and the drug-resistance rate. Results (1) The number of specimens examined showed no statistical difference during the five years ( with rates from 73.2% to 76.1% , x 2 = 5. 583, P ＞ 0.05 ) , while constituent ratio of cocci and bacilli showed statistical difference (with ratios from 105:134 to 169: 126, x 2 =14. 806, P ＜0.01 ). The positive rates of bacteria were increasing in the five years. (2) One thousand six hundred and seventy-five strains were identified during the five years from different kinds of specimens, with 29 from blood, 39 from venous catheter, 3 from stool, 157 from sputum, 13 from urine, and 1434 from wound tissue. Among them, Staphylococcus aureus accounted for 28% to 42% , PA accounted for 10% to 25% , Acinetobacter baumannii accounted for 10% to 19% , and they were the predominant strains. (3)The difference among drug-resistance rates of PA to each kind of 12 antibiotics during the five years were statistically significant (with x2 values from 47. 911 to 308. 095, P values all below 0.01 ). The drug-resistance rates of PA to some antibiotics showed downward trend in the former four years, including amikacin,ceftazidime, and imipenem/cilastatin, but it rebounded in the fifth year. (4) There was descending trend in usage of cefoperazone/sulbactam and levofloxacin, but vancomycin was always used widely. (5) Drug-resistance rates of PA to 7 antibiotics, including amikacin, imipenem/cilastatin, and ciprofloxacin, etc. , were positively correlated with usage of various antibiotics (with r values from 0. 879 to 0. 978, P ＜ 0. 05 or P ＜0. 01). Conclusions In our burn wards, drug-resistant PA was prevalent. Disinfection and isolation measures,appropriate use of antibiotics,etc. can reduce PA infection.     

重症监护病房铜绿假单胞菌感染的危险因素和耐药性分析

目的 研究重症监护病房(icu)铜绿假单胞菌感染的发生率、危险因素及耐药情况.方法 收集171例脓毒症患者,分离培养铜绿假单胞菌并进行药敏试验.采用spss10.0统计学软件对可能的危险因素进行logistic回归分析.结果 171例脓毒症患者中,发生铜绿假单胞菌感染37例,分离培养出 45株铜绿假单胞菌.多因素logistic回归分析显示,近期抗菌药物使用史(or=4.291,95%ci:1.727～10.662)、住icu时间(or=1.117,95%ci:1.058～1.181)、机械通气(or=3.400,95%ci:1.348～8.579)以及中心静脉导管的使用(or=3.339,95%ci:1.322～8.434)为铜绿假单胞菌感染的独立危险因素.药敏试验显示铜绿假单胞菌对头孢寨肟的耐药率最高(68.9%),18株(40%)菌株表现为多重耐药.结论 铜绿假单胞菌足icu常见的病原菌,具有多重耐药性.加强抗菌药物的合理使用、严格执行各种有创导管的无菌操作是减少铜绿假单胞菌耐约的重要措施. abstract： objective to investigate the incidence, risk factors and drug-resistance of pseudomonas aeruginosa infection in intensive care unit (icu). methods totally 171 patients with sepsis admitted in icu were enrolled. pathogenic bacteria culture and antimicrobial susceptibility tests were performed. spss10. 0 software was used for logistic regression analysis of the risk factors. results pseudomonas aeruginosa infection was confirmed in 37 patients, and 45 strains of pseudomonas aeruginosa were isolated. logistic regression revealed that recent antibiotics use ( or = 4. 291 , 95% ci: 1. 727-10. 662) , length of icu stay (or = 1.117, 95% ci: 1.058-1. 181) , mechanical ventilation (or = 3.400, 95% ci: 1.348-8.579) and central venous catheterization (or =3. 339, 95% ci: 1.322-8.434) were independent risk factors of pseudomonas aeruginosa infection. the resistance rate of cefotaxime was the highest (68.9%) and 18 strains (40%) were multidrug-resistant. conclusions pseudomonas aeruginosa infection is common in icu and it is usually multidrug resistant. the rational use of antibiotics and aseptic technique of invasive catheterization are important for the prevention of pseudomonas aeruginosa infection.     

2009至2011年铜绿假单胞菌的临床分布及耐药分析

目的：分析2009至2011年本院临床分离出来的铜绿假单胞菌耐药性的变迁,为临床合理的给药方案提供参考。方法采用肉汤稀释法对临床分离出的2781株病原菌中的252株铜绿假单胞菌对12种抗菌药物进行药敏分析。结果临床上分离铜绿假单胞菌标本主要为痰和支气管灌洗液下呼吸道标本,占62.3%（157/252）。铜绿假单胞菌感染发生率主要分布在ICU 27.8%（70/252）和感染科19.8%（50/252）。铜绿假单胞菌对大多抗菌药物的耐药性逐年增加,尤其亚胺培南和美洛培南已经达到41%（30/74）和35%（22/74）,敏感性最高的为多粘菌素B和氨基糖苷类阿米卡星。结论铜绿假单胞菌感染有上升趋势,对常用抗生素耐药率增加,需引起临床重视。加强其耐药监测可以为临床提供治疗依据。     

烧伤病房铜绿假单胞菌耐药率及抗菌药使用变化

Objective To study changes in the drug-resistance of Pseudomonas aeruginosa (PA)and the use of antibiotics in burn wards so as to optimize the use of antibiotic in the future. Methods Bacteria were isolated from specimens of blood, venous catheter, stool, sputum, urine, wound tissue from 5717 patients hospitalized in our burn wards within the duration of January 2005 to December 2009. The number of specimens examined and positive rates of bacteria were calculated. Changes in constituent ratio of cocci and bacilli, spectrum of bacteria, the drug-resistance rate of PA, and the usage of antibiotics were analyzed. The number of specimens examined, constituent ratio of cocci and bacilli, drug-resistance rate were processed with chi-square test. Bivariate correlation analysis was performed between the usage of antibiotics and the drug-resistance rate. Results (1) The number of specimens examined showed no statistical difference during the five years ( with rates from 73.2% to 76.1% , x 2 = 5. 583, P ＞ 0.05 ) , while constituent ratio of cocci and bacilli showed statistical difference (with ratios from 105:134 to 169: 126, x 2 =14. 806, P ＜0.01 ). The positive rates of bacteria were increasing in the five years. (2) One thousand six hundred and seventy-five strains were identified during the five years from different kinds of specimens, with 29 from blood, 39 from venous catheter, 3 from stool, 157 from sputum, 13 from urine, and 1434 from wound tissue. Among them, Staphylococcus aureus accounted for 28% to 42% , PA accounted for 10% to 25% , Acinetobacter baumannii accounted for 10% to 19% , and they were the predominant strains. (3)The difference among drug-resistance rates of PA to each kind of 12 antibiotics during the five years were statistically significant (with x2 values from 47. 911 to 308. 095, P values all below 0.01 ). The drug-resistance rates of PA to some antibiotics showed downward trend in the former four years, including amikacin,ceftazidime, and imipenem/cilastatin, but it rebounded in the fifth year. (4) There was descending trend in usage of cefoperazone/sulbactam and levofloxacin, but vancomycin was always used widely. (5) Drug-resistance rates of PA to 7 antibiotics, including amikacin, imipenem/cilastatin, and ciprofloxacin, etc. , were positively correlated with usage of various antibiotics (with r values from 0. 879 to 0. 978, P ＜ 0. 05 or P ＜0. 01). Conclusions In our burn wards, drug-resistant PA was prevalent. Disinfection and isolation measures,appropriate use of antibiotics,etc. can reduce PA infection.     

烧伤病房铜绿假单胞菌耐药率及抗菌药使用变化

Objective To study changes in the drug-resistance of Pseudomonas aeruginosa (PA)and the use of antibiotics in burn wards so as to optimize the use of antibiotic in the future. Methods Bacteria were isolated from specimens of blood, venous catheter, stool, sputum, urine, wound tissue from 5717 patients hospitalized in our burn wards within the duration of January 2005 to December 2009. The number of specimens examined and positive rates of bacteria were calculated. Changes in constituent ratio of cocci and bacilli, spectrum of bacteria, the drug-resistance rate of PA, and the usage of antibiotics were analyzed. The number of specimens examined, constituent ratio of cocci and bacilli, drug-resistance rate were processed with chi-square test. Bivariate correlation analysis was performed between the usage of antibiotics and the drug-resistance rate. Results (1) The number of specimens examined showed no statistical difference during the five years ( with rates from 73.2% to 76.1% , x 2 = 5. 583, P ＞ 0.05 ) , while constituent ratio of cocci and bacilli showed statistical difference (with ratios from 105:134 to 169: 126, x 2 =14. 806, P ＜0.01 ). The positive rates of bacteria were increasing in the five years. (2) One thousand six hundred and seventy-five strains were identified during the five years from different kinds of specimens, with 29 from blood, 39 from venous catheter, 3 from stool, 157 from sputum, 13 from urine, and 1434 from wound tissue. Among them, Staphylococcus aureus accounted for 28% to 42% , PA accounted for 10% to 25% , Acinetobacter baumannii accounted for 10% to 19% , and they were the predominant strains. (3)The difference among drug-resistance rates of PA to each kind of 12 antibiotics during the five years were statistically significant (with x2 values from 47. 911 to 308. 095, P values all below 0.01 ). The drug-resistance rates of PA to some antibiotics showed downward trend in the former four years, including amikacin,ceftazidime, and imipenem/cilastatin, but it rebounded in the fifth year. (4) There was descending trend in usage of cefoperazone/sulbactam and levofloxacin, but vancomycin was always used widely. (5) Drug-resistance rates of PA to 7 antibiotics, including amikacin, imipenem/cilastatin, and ciprofloxacin, etc. , were positively correlated with usage of various antibiotics (with r values from 0. 879 to 0. 978, P ＜ 0. 05 or P ＜0. 01). Conclusions In our burn wards, drug-resistant PA was prevalent. Disinfection and isolation measures,appropriate use of antibiotics,etc. can reduce PA infection.     

纳米银敷料用于深Ⅱ°烧伤创面铜绿假单胞菌感染的疗效观察

目的:观察纳米银敷料用于深Ⅱ°烧伤创面铜绿假单胞菌感染的疗效.方法:选择深Ⅱ°烧伤创面合并铜绿假单胞菌感染的患者33例,随机分为纳米银敷料组(实验组)18例及磺胺嘧啶银软膏组(对照组)15例,创面换药每日一次,于用药后第7天及第10天行创面细菌培养,观察创面愈合时间.结果:实验组于用药后第7天及第10天创面细菌培养阳性率分别为22.2%(4例)和5.5%(1例),创面平均愈合时间为15.6±2.4天;对照组于用药后第7天及第10天细菌培养阳性率分别为46.7%(7例)和13.3%(2例),创面平均愈合时间为19.6±3.4天.结论:纳米银敷料可有效治疗合并有铜绿假单胞菌感染的深Ⅱ°烧伤创面,并缩短创面愈合时间.     

Antimicrobial dressing efficacy against mature Pseudomonas aeruginosa biofilm on porcine skin explants

An ex vivo porcine skin explant biofilm model that preserves key properties of biofilm attached to skin at different levels of maturity (0–3 days) was used to assess the efficacy of commercially available antimicrobial dressings and topical treatments. Assays were also performed on the subpopulation of antibiotic tolerant biofilm generated by 24 hours of pre‐treatment with gentamicin (120× minimal inhibitory concentration) prior to agent exposure. Five types of antimicrobial agents (iodine, silver, polyhexamethylene biguanide, honey and ethanol) and four types of moisture dressings (cotton gauze, sodium carboxymethylcellulose fibre, calcium alginate fibre and cadexomer beads) were assessed. Time‐release silver gel and cadexomer iodine dressings were the most effective in reducing mature biofilm [between 5 and 7 logarithmic (log) of 7‐log total], whereas all other dressing formulations reduced biofilm between 0·3 and 2 log in 24 or 72 hours with a single exposure. Similar results were found after 24‐hour exposure to silver release dressings using an in vivo pig burn wound model, demonstrating correlation between the ex vivo and in vivo models. Results of this study indicate that commonly used microbicidal wound dressings vary widely in their ability to kill mature biofilm and the efficacy is influenced by time of exposure, number of applications, moisture level and agent formulation (sustained release).     

Promotion of acute‐phase skin wound healing by Pseudomonas aeruginosa C4‐HSL

A Pseudomonas aeruginosa quorum‐sensing system, which produces N‐(3‐oxododecanoyl)‐l ‐homoserine lactone (3‐oxo‐C₁₂‐HSL) and N‐butanoyl‐l ‐homoserine lactone (C₄‐HSL), regulates the virulence factors. In our previous study, 3‐oxo‐C₁₂‐HSL, encoded by lasI gene, was shown to promote wound healing. However, the effect of C₄‐HSL, encoded by rhlI gene, remains to be elucidated. We addressed the effect of C₄‐HSL on wounds in P. aeruginosa infection. Wounds were created on the backs of Sprague–Dawley SD rats, and P. aeruginosa PAO1 (PAO1) or its rhlI deletion mutant (ΔrhlI) or lasI deletion mutant (ΔlasI) was inoculated onto the wound. Rats were injected intraperitoneally with anti‐C₄‐HSL antiserum or treated with C₄‐HSL at the wound surface. PAO1 inoculation led to significant acceleration of wound healing, which was associated with neutrophil infiltration and TNF‐α synthesis. These responses were reversed, except for TNF‐α production, when ΔrhlI was inoculated instead of PAO1 or when rats were co‐treated with PAO1 and anti‐C₄‐HSL antiserum . In contrast, the healing process and neutrophil infiltration, but not TNF‐α synthesis, were accelerated when C₄‐HSL was administered in the absence of PAO1. This acceleration was not affected by anti‐TNF‐α antibody. These results suggest that C₄‐HSL may be involved in the acceleration of acute wound healing in P. aeruginosa infection by modifying the neutrophilic inflammation.     

Clinician perceptions of wound biofilm

In wound care today, biofilm is a subject area of great interest and debate. There is an increasing awareness that biofilm exists in the majority of non‐healing wounds, and that it is implicated in both recalcitrance and infection. Together with the presence of devitalised host tissue, biofilm is recognised as a component of the wound environment that requires removal to enable wound progression. However, uncertainty exists among wound care practitioners regarding confirmation of the presence of biofilm, and how best to remove biofilm from a non‐healing wound. While recent efforts have been taken to assist practitioners in signs and symptoms of wound biofilm, continuing research is required to characterise and confirm wound biofilm. This research was conducted as part of a market research process to better understand the knowledge levels, experiences, clinical awareness and impact of biofilm in wound care, which was undertaken across the USA and Europe. While knowledge levels and experiences vary from country to country, certain wound characteristics were consistently associated with the presence of biofilm.     

Pseudomonas aeruginosa biofilm hampers murine central wound healing by suppression of vascular epithelial growth factor

Biofilm‐infected wounds are clinically challenging. Vascular endothelial growth factor and host defence S100A8/A9 are crucial for wound healing but may be suppressed by biofilms. The natural course of Pseudomonas aeruginosa biofilm infection was compared in central and peripheral zones of burn‐wounded, infection‐susceptible BALB/c mice, which display delayed wound closure compared to C3H/HeN mice. Wounds were evaluated histopathologically 4, 7 or 10 days post‐infection. Photoplanimetry evaluated necrotic areas. P. aeruginosa biofilm suppressed vascular endothelial growth factor levels centrally in BALB/c wounds but increased peripheral levels 4–7 days post‐infection. Central zones of the burn wound displayed lower levels of central vascular endothelial growth factor as observed 4 and 7 days post‐infection in BALB/c mice compared to their C3H/HeN counterparts. Biofilm suppressed early, centrally located S100A8/A9 in BALB/c and centrally and peripherally later on in C3H/HeN wounds as compared to uninfected mice. Peripheral polymorphonuclear‐dominated inflammation and larger necrosis were observed in BALB/c wounds. In conclusion, P. aeruginosa biofilm modulates wounds by suppressing central, but inducing peripheral, vascular endothelial growth factor levels and reducing host response in wounds of BALB/c mice. This suppression is detrimental to the resolution of biofilm‐infected necrosis.     

抗菌肽天蚕素B对铜绿假单胞菌感染小鼠创面的抗菌作用

目的观察抗菌肽天蚕素B对小鼠铜绿假单胞菌感染创面的抗菌效果。方法于30只ICR小鼠背部切除全层皮肤(创面为1 cm×1 cm),将铜绿假单胞菌菌液涂抹于创面制成感染模型,并随机分为对照组、磺胺米隆组、抗菌肽组,伤后3 h分别用含等渗盐水、100 g／L磺胺米隆溶液、1g／L天蚕素B的纱布湿敷,每组10只。伤后1～4 d对各组小鼠创面行大体观察;伤前和伤后4 d测量体温,抽取血液观察白细胞变化;伤后4 d检测痂下肌肉组织细菌定量和观察存活情况。结果对照组创面分泌物多、创面潮湿;磺胺米隆组、抗菌肽组创面结痂、干燥、无明显分泌物。各组小鼠术后体温多数上升、白细胞计数均减少。抗菌肽组痂下肌肉组织细菌定量为(42±50)集落形成单位(CFU)／g,明显少于磺胺米隆组(886±804)CFU／g(P<0．05),两组均明显低于对照组(41±28)×105CFU／g(P<0．01)。对照组小鼠伤后4 d存活数明显少于抗菌肽组、磺胺米隆组(P<0．05)。结论天蚕素B对ICR小鼠铜绿假单胞菌感染创面有明显的抗感染作用,可明显降低其死亡率。     

不同强度低频超声联合环丙沙星对铜绿假单胞菌生物膜的作用

目的探讨不同强度低频超声联合环丙沙星对铜绿假单胞菌(PA)生物膜的作用。方法建立PA菌株生物膜模型,随机分为对照组、环丙沙星组、10mW/cm2低频超声组、100mW/cm2低频超声组、300mW/cm2低频超声组、10mW/cm2低频超声+环丙沙星组、100mW/cm2低频超声+环丙沙星组、300mW/cm2低频超声+环丙沙星组,测定各组BF细菌活力的变化,激光共聚焦显微镜观察并定量分析生物膜结构。结果与对照组比较,环丙沙星组、10mW/cm2低频超声组、100mW/cm2低频超声组、300mW/cm2低频超声组生物膜中细菌活力水平、生物膜厚度、区域孔径(AP)、平均扩散距离(ADD)和结构熵(TE)无显著变化(P均0.05),10mW/cm2低频超声+环丙沙星组、100mW/cm2低频超声+环丙沙星组和300mW/cm2低频超声+环丙沙星组生物膜中细菌活力明显降低、生物膜厚度变薄、AP增大、ADD与TE减小(P均0.05),且呈辐照剂量依赖性。结论低频超声可有效增强环丙沙星对PA生物膜的清除作用,且呈辐照剂量依赖性。     

Clinico‐microbiological study of Pseudomonas aeruginosa in wound infections and the detection of metallo‐β‐lactamase production

Pseudomonas aeruginosa is a common opportunistic pathogen of humans among the Gram‐negative bacilli. Clinically, it is associated with nosocomial infections like burns and surgical‐site wound infections and remains a major health concern, especially among critically ill and immunocompromised patients. This is a prospective laboratory‐based 2 year study conducted to isolate P. aeruginosa from wound specimens and the antimicrobial susceptibility pattern with reference to metallo‐β‐lactamase (MBL) production. Two hundred and twenty‐four samples of P. aeruginosa isolated from wound specimens were included in the study. Antimicrobial susceptibility was done as per Clinical Laboratory Standard Institute (CLSI) guidelines. MBL‐producing P. aeruginosa was detected using the EDTA disk diffusion synergy test. Statistical analysis was done using the SPSS 11 package (SPSS Inc., Chicago, IL). Out of the 224 P. aeruginosa isolates, 100% were susceptible to polymyxin B and colistin, 92·8% were sensitive to imipenem, 38% showed resistance to gentamicin followed by ceftazidime (31·69%) and meropenem (33·03). Sixteen (7·14%) isolates showed MBL production. Infection caused by drug‐resistant P. aeruginosa is important to identify as it poses a therapeutic problem and is also a serious concern for infection control management. The acquired resistance genes can be horizontally transferred to other pathogens or commensals if aseptic procedures are not followed.     

Detection of Pseudomonas aeruginosa quorum sensing signals in an infected ischemic wound: An experimental study in rats

Quorum sensing is a cell-to-cell communication that occurs via autoinducers, regulating a number of bacterial virulence factors including the opportunistic wound pathogen Pseudomonas aeruginosa , which uses the N -(3-oxododecanoyl)-homoserine lactone as one of the two main autoinducers; however, little is known about its role in chronic wound infection. This study was designed to quantify this autoinducer from P. aeruginosa- infected wounds with the aim of examining the possible use of autoinducers as an indicator of chronic wound infection. Pressure-induced ischemic wounds were infected with P. aeruginosa ( N =12) or uninfected as a control ( N =12). The autoinducer was quantified by bioassay method employing Escherichia coli DH5α (pJN105L, pSC11) or Agrobacterium tumefaciens NTL4 (pZLR4) reporter, which expresses β-galactosidase when exposed to P. aeruginosa quorum sensing signals. The average concentration of autoinducer was 0.33 pmol/g at day 3 and 0.49 pmol/g at day 7 in the infected wounds, as detected from tissue samples. A linear correlation between autoinducer concentration and bacterial counts was observed. No autoinducer was detected in tissue samples from the uninfected control group. Our findings indicate that the quantification of autoinducers is possible and quorum sensing system could play a role in in vivo wound infection models, and also suggest possible clinical implications of autoinducer signal quantification in diagnosis of chronic wound infection.     

Silver coating of urinary catheters prevents adherence and growth of Pseudomonas aeruginosa

Summary Discs of urinary catheter material were exposed to the flow of artificial urine containing cells of Pseudomonas aeruginosa. Within 10 h an adherent biofilm composed of the bacteria and of their exopolysaccharide products had developed on the uncoated catheter material. On the silver-coated catheter material no biofilm of Pseudomonas aeruginosa had developed.