呼吸重症监护病房2008年至2011年医院感染病原菌分布及危险因素分析

目的：对我院呼吸重症监护病房（RICU）临床分离的非重复性感染病原菌的耐药性进行调查,分析RICU院内感染的危险因素。方法：收集RICU 2008年-2011年临床分离的非重复性感染病原菌及相关临床资料分析医院感染的危险因素。结果：（1）2008-2011年RICU院内感染发生率为34.15%,每年分离的前3位病原菌均为鲍曼不动杆菌、金黄色葡萄球菌及铜绿假单胞菌;（2）大肠杆菌连续4年ESBLs检出率为100%,四年间肺炎克雷伯菌ESBLs检出率最高达95.5%,葡萄球菌中MRSA检出率较高（〉89.6%）;（3）RICU院内感染以下呼吸道感染最为常见,其次为泌尿道感染,血液感染位于第3位;（4）多因素非条件logistic回归分析发现机械通气、住院时间〉15天及联合应用抗菌药物是RICU医院感染的危险因素。结论：（1）连续4年RICU感染病原菌以革兰阴性杆菌为主;（2）ESBLs和MRSA检出率较高,给临床抗感染治疗带来巨大的挑战;（3）机械通气、住院时间〉15天及联合应用抗菌药物是RICU医院感染的危险因素。     

医院内尿路感染致病菌变迁及其耐药性监测分析

目的调查院内尿路感染致病菌分布及耐药性变化情况.方法对我院1998年1月-2000 年12月医院内尿路感染患者分离的细菌菌株、真菌菌株及细菌耐药性进行回顾性调查.结果 医院内尿路感染仍以G 菌为主(39.9%),其次为真菌(32.9%),G+菌(27.2%);G -菌以大肠埃希菌为主(41.7%),G+菌以D组链球菌为主(50.3%),真菌以白色念珠菌为主(44.7%),与19 98年分离的菌株相比,2000年G 菌所占比例有下降趋势,而真菌由25.7%上升至36.6%(P< 0.05),3年间主要病原菌对常用抗生素的耐药率基本呈上升趋势.结论院内尿路感染致病菌正在发生变迁 ,耐药性严重,临床应重视病原学检查,开展细菌耐药性监测,合理使用抗生素.     

Serratia marcescens: Biochemical, Serological, and Epidemiological Characteristics and Antibiotic Susceptibility of Strains Isolated at Boston City Hospital

The biochemical, serological, and epidemiological characteristics of 95 strains of Serratia marcescens isolated at the Boston City Hospital were examined. Several strains were shown to be endemic, and the majority of isolates were cultured from urine or respiratory secretions. Serratia species were highly resistant to polymyxin B and the cephalosporins, and various proportions were also resistant to other antibiotics including kanamycin, but all of the isolates were sensitive to gentamicin. The appearance of resistance to kanamycin and nalidixic acid among endemic strains was demonstrated. The nosocomial nature of Serratia infections, particularly those involving the urinary tract, was confirmed. Many clinical bacteriology laboratories currently fail to identify the nonpigmented strains.     

下呼吸道不动杆菌医院感染的危险因素及耐药性分析

目的了解引起下呼吸道医院感染的不动杆菌耐药现状及存在的危险因素。方法用常规的方法对下呼吸道的标本进行病原菌的培养及分离,用全自动微生物分析仪VITEK 2对细菌进行鉴定及药物敏感性试验,同时对由不动杆菌引发的158例院内感染患者的危险因素进行分析。结果不动杆菌引起下呼吸道医院感染相关的危险因素主要为使用糖皮质激素类药物或机械插管或患有糖尿病等;除亚胺培南、左氧氟沙星、头孢吡肟、头孢哌酮、头孢哌酮/舒巴坦及头孢他啶等对不动杆菌有较好的体外抗菌活性外(耐药率小于40.0%),临床常用的其他多种抗菌药物耐药较严重,耐药率均在40.0%以上。结论糖皮质激素,机械插管,糖尿病等是不动杆菌引起下呼吸道医院感染的主要危险因素,不动杆菌对临床常用的抗生素有多重耐药性。     

老年患者阴沟肠杆菌感染的临床特点及耐药性分析

目的了解我院老年患者阴沟肠杆菌感染的临床分布及耐药性变迁,为临床合理用药提供参考依据。方法采用回顾性分析方法,统计临床数据并分析我院2011年9月至2016年4月期间老年患者感染标本中分离出的阴沟肠杆菌的感染现状及耐药性。结果共检出149株阴沟肠杆菌,主要分离于痰液、全血和尿液中,分别占31.54%、24.16%和18.12%。在科室分布中,阴沟肠杆菌感染主要来源于普通外科、重症监护病房和呼吸内科,分别占26.84%、14.10%和14.10%。药敏结果显示阴沟肠杆菌对美罗培南、亚胺培南和阿米卡星具有较好的抗菌活性,敏感率分别为100.00%、96.64%和95.97%,而对阿莫西林/克拉维酸、氨苄西林、头孢替坦、头孢西丁和头孢唑啉的耐药率分别为96.36%、96.36%、97.67%、100.00%和100.00%。结论阴沟肠杆菌易引起呼吸道、泌尿道以及伤口的感染,且其耐药现象较为严重,应加强耐药性的监测,根据药敏结果合理选用抗菌药物,以控制医院感染。     

Susceptibility of antibiotic-resistant gram-negative bacteria to biocides: a perspective from the study of catheter biofilms

Bacteria resistant to both the agents deployed to prevent infections and those used to treat infections would be formidable nosocomial pathogens. The aim of this paper is to review the evidence that gram-negative bacteria resistant to antibiotics and biocides have emerged and been responsible for catheter-associated urinary tract infection. A study of patients undergoing intermittent bladder catheterization revealed that the frequent application of the antiseptic chlorhexidine to the perineal skin prior to the insertion of the catheter was effective against the normal gram-positive skin flora but not against the gram-negative organisms that subsequently colonized this site. Organisms such as Providencia stuartii, Pseudomonas aeruginosa and Proteus mirabilis were repeatedly isolated from the skin of these patients and inevitably went on to cause urinary infections. The minimum inhibitory concentration (MIC) of chlorhexidine for many of these strains proved to be 200-800 microg ml(-1) compared with the 10-50 microg ml(-1) recorded for reference strains of gram-negative species. A subsequent survey of over 800 gram-negative isolates from urinary tract infections in patients from both hospitals and the community revealed that chlorhexidine resistance was not a widespread phenomenon, but was restricted to these species and to units where the care of catheterized patients involved the extensive use of chlorhexidine. Analysis of the antibiotic resistance patterns revealed that the chlorhexidine-resistant strains were also multidrug resistant. Other clinical studies also reported catheter-associated infections with chlorhexidine- and multidrug-resistant strains of Pr. mirabilis when chlorhexidine was being used extensively. This species poses particular problems to the catheterized patient. Chlorhexidine thus proved counterproductive in the care of catheters and its use in this context has been largely abandoned. Suggestions of reintroducing this agent in the form of biocide-impregnated catheters should be resisted.     

神经内外科院内泌尿道感染病原菌分布及耐药性比较

目的研究我院神经内外科院内泌尿道感染的菌群分布和药敏情况,为临床合理应用抗菌药物提供依据。方法回顾性分析2004年1月至2005年6月神经内外科院内泌尿道感染的菌群分布、药敏情况及易感因素。结果神经内科和神经外科均以革兰阳性菌感染为主,分别占48.59%、40.19%,而阳性菌中又以肠球菌为主;神经外科院内泌尿道真菌的院内感染比例(21.39%)明显高于神经内科(14.06%)(P<0.05)。药敏结果显示:神经内外科大肠埃希菌较敏感的抗菌药物为头孢替坦、亚胺培南等。检出肠球菌125株,除对万古霉素和替考拉宁敏感以外,对其他抗菌药物均有较高的耐药。结论神经内外科院内泌尿道感染病原菌正发生变迁,以阳性菌为主,抗菌药物的使用不同可能是造成神经内外科菌群分布不同的重要原因。     

Nosocomial urinary infection due to Trichosporon asahii. First two cases in Chile

We present two cases of nosocomial urinary tract infection due to Trichosporon asahii in intensive care unit patients with bladder catheter from two hospitals in Santiago, Chile. Both patients had an several catheters and bacterial infections that required the use of antibiotic therapy. One strain showed in vitro resistance to amphotericin B. Both strains were susceptible to fluconazole, but presented MIC with dose-dependent susceptibility to ketoconazole and itraconazole. This is the first report showing T. asahii as urinary tract infection agent in Chile.     

Biochemistry and molecular genetics of poly-γ-glutamate synthesis

Current research into poly-gamma-glutamate (PGA) and its biosynthesis is reviewed. In PGA-producing Bacillus subtilis, glutamate racemase supplies abundant DL-glutamate, the substrate for PGA synthesis. The pgsBCA genes of PGA-producing B. subtilis, which encode the membrane-associated PGA synthetase complex PgsBCA, were characterized and the enzyme complex was suggested to be an atypical amide ligase based on its structure and function. A novel reaction mechanism of PGA synthesis is proposed.     

Isolation of Bacillus subtilis (chungkookjang), a poly-γ-glutamate producer with high genetic competence

A bacterium with high poly-gamma-glutamate (PGA) productivity was isolated from the traditional Korean seasoning, Chung-Kook-Jang. This bacterium could be classified as a Bacillus subtilis, but sporulation in culture was infrequent in the absence of Mn2+. It was judged to be a variety of B. subtilis and designated B. subtilis (chungkookjang). L-Glutamate significantly induced PGA production, and highly elongated PGAs were synthesized. The volumetric yield reached 13.5 mg ml(-1) in the presence of 2% L-glutamate. The D-glutamate content was over 50% in every PGA produced under the conditions used. During PGA production, glutamate racemase activity was found in the cells, suggesting that the enzyme is involved in the D-glutamate supply. Molecular sizes of PGAs were changed by the salt concentration in the medium; PGAs with comparatively low molecular masses were produced in culture media containing high concentrations of NaCl. B. subtilis (chungkookjang) harbors no plasmid and is the first B. subtilis strain reported with both naturally high PGA productivity and high genetic competence.     

Glycopeptide resistance in enterococci.

The selective pressure resulting from the extensive use of antibiotics over the last 50 years has led to the emergence of bacterial resistance and to the dissemination of resistance genes among pathogenic microorganisms. Consequently, we are now at serious risk of suffering intractable, life-threatening infections. The progressive emergence and rapid dissemination of resistance to glycopeptides, the last resort for treating nosocomial infections with enterococci resistant to usual antibiotics, constitute one of the most dramatic examples of such resistance. Enterococci are normal human commensals, but are also a frequent cause of nosocomial urinary tract infections and nosocomial bacteremia. Enterococcus faecalis causes 80 to 90% of human enterococcal infections, while Enterococcus faecium accounts for most of the remainder. During the last decade, our understanding of the genetics and biochemical basis of resistance to glycopeptides has increased greatly. Furthermore, the application of molecular methods for the diagnosis of glycopeptide-resistant enterococci has provided new insights into the epidemiology of enterococcal infections.     

Draft Genome Sequence of Serratia marcescens Strain LCT-SM213

Serratia marcescens is a species of Gram-negative, rod-shaped bacterium of the family Enterobacteriaceae. S. marcescens can cause nosocomial infections, particularly catheter-associated bacteremia, urinary tract infections, and wound infections. Here, we present the draft genome sequence of Serratia marcescens strain LCT-SM213, which was isolated from CGMCC 1.1857.     

1168例医院感染患者病原菌的调查及其影响因素的探讨

医院感染发病率较高且易于引起医患纠纷。为了解影响医院感染的主要因素及其主要病原体,对陕西省宝鸡市第二人民医院2002—2007年1168例医院感染患者进行了病原菌分离、鉴定及分析,同时对患者基础疾病及感染部位与医院感染的关系进行了探讨。实验结果表明,在临床各科室中,ICU患者医院感染比例（40．6％）最高（P〈0．01）,其次为烧伤科（13．3％）、泌尿外科（10．6％）和血液科患者（8．2％）（P〈0．05）。下呼吸道是最为常见的感染部位（33．9％,P〈0．01）,其次为泌尿道、胃肠道、手术切口、烧伤创面和血液（10．3％～14．7％,P〈0．05）。1168例医院感染患者标本中,病原菌总阳性率为67．3％（786／1168）。786株病原菌中,革兰阴性菌所占58．7％、革兰阳性菌占26．4％、真菌占14．9％。所分离的革兰阴性菌中,以铜绿假单胞菌（16．9％）、克雷伯菌（15．2％）和大肠埃希菌（11．7％）最为常见。所分离的革兰阳性菌中,以金黄色葡萄球菌（9．3％）和表皮葡萄球菌（7．2％）最为常见。     

心内科患者医院感染鲍氏不动杆菌的耐药性分析

目的了解心内科住院患者医院感染鲍氏不动杆菌的耐药性,为指导临床合理用药提供依据。方法从2010—2012年心内科住院患者送检标本中分离鲍氏不动杆菌,采用PHOENIX-100全自动细菌鉴定药敏系统进行细菌鉴定及药敏试验,并对结果进行统计分析。结果2010-2012年心内科住院患者共分离出166株鲍氏不动杆菌,其中泛耐药菌株34株,检出率为20．5％。药敏结果显示鲍氏不动杆菌对常用抗菌药物的耐药率呈逐年上升趋势,并显示出多重耐药性,对多粘菌素B、头孢哌酮／舒巴坦、亚胺培南和美罗培南等耐药率相对较低。结论鲍氏不动杆菌已成为医院感染重要病原菌,对多种抗菌药物耐药,临床应加强耐药性监测,根据药敏结果合理选用抗菌药物,以控制医院感染的暴发流行。     

泌尿外科住院患者泌尿系感染病原菌分布及其耐药性分析

了解泌尿外科住院患者泌尿系感染病原菌的分布及其对常用抗菌药物的耐药情况。对泌尿外科泌尿系感染住院患者的消毒中段尿培养结果进行回顾性分析,尿培养菌株的鉴定、药敏分析和统计分析采用VITEK2全自动微生物仪。3 a中泌尿外科泌尿系感染住院患者共分离到细菌1 233株,其中革兰阴性杆菌772株,占62.61%,革兰阳性球菌353株,占28.63%,真菌82株,占6.65%。菌株数居前5位的细菌依次为:大肠埃希菌、肠球菌属、洋葱伯克霍尔德菌、假丝酵母菌属和变形杆菌。分离大肠埃希菌产ESBLs率为66.18%,粪肠球菌中未发现VRE菌株,屎肠球菌VRE为0.8%。未发现对美洛培南耐药的大肠埃希菌,对肠埃希菌耐药率在10%以下的有亚胺培南、阿米卡星、哌拉西林/他唑巴坦和呋喃妥因。洋葱伯克霍尔德菌和铜绿假单胞菌对所监测的抗菌药物均有不同程度的耐药。未发现对万古霉素、替考拉宁及氨苄西林耐药的粪肠球菌。泌尿系感染的病原菌以大肠埃希菌和肠球菌为主,非发酵革兰阴性杆菌及假丝酵母菌所占比例超过20%,不容忽视,病原菌的耐药率较高,临床医生应根据尿培养和药敏试验结果合理使用抗菌药物。     

Effect of antibiotic treatment on receptivity of uroepithelial cells to uropathogens

The management of female patients with recurrent urinary tract infections still remains a problem, and long-term prophylactic or short intermittent courses of antibiotics are the standard forms of therapy. In this report, 10 patients were examined for the effects of long- and short-term treatment with trimethoprim-sulfamethoxazole (TMP-SMX) antibiotics on the receptivity of uroepithelial cells to bacterial adherence. The urine of all patients was sterile while on antibiotic therapy. Few bacteria were found adherent to the cells from adult patients (group 1, mean age 36 years) on long-term antibiotics, but the cells were highly receptive to uropathogens in vitro, especially for Escherichia coli expressing mannose-resistant adhesins. Controls of age-matched adult females were included and in vitro adherence levels were found to be higher for those women with a history of urinary tract infection compared with those with no past record of infection. In the second group, elderly patients (mean age 87 years) presented with bacteriuria, and their uroepithelial cells were found to be colonized by uropathogens to a significantly greater extent than their controls. The adherent population was reduced during 7-day TMP-SMX antibiotic treatment, but increased posttherapy, particularly in two patients who subsequently became reinfected. The in vitro results showed that uroepithelial cells retain their receptivity to uropathogenic adherence, both during and after treatment. Although antibiotics eradicate uropathogens from the urinary tract, patients remain susceptible to recolonization by uropathogens and are at risk of reinfection after completion of therapy.     

尿路感染相关病原菌的分布及耐药性分析

目的调查尿路感染病原菌的分布和耐药特点,为临床的抗感染治疗提供依据。方法收集2013年至2015年荆州市中心医院门诊和住院患者中,尿路感染患者送检的尿培养和血培养标本中检出的病原菌,采用Vitek2 Compact全自动微生物检测仪进行细菌鉴定,采用纸片扩散法和仪器法分别对革兰阴性杆菌和革兰阳性球菌进行药敏试验,药敏结果的判断依照CLSI M100-S24标准。数据分析采用WHONET5.6和SPSS 19.0软件,统计分析采用x~2检验。结果从尿路感染患者送检的标本中共检出各类非重复病原菌2 306株,其中门诊患者中检出19种100株,住院患者检出56种2 206株。导致尿路感染最多的两种病原菌为大肠埃希菌和粪肠球菌,分别检出1 241株和232株。导致尿脓毒血症最多的两种病原菌为大肠埃希菌和肺炎克雷伯菌,分别检出36株和10株。大肠埃希菌产ESBL.s率达67.9%,其对多种抗菌药物的耐药性均高于60.0%。粪肠球菌对大多数抗菌药物的耐药性均高于50.0%,仅对呋喃妥因和高浓度链霉素的耐药性较低,分别为12.0%和38.7%;未检出对万古霉素、利奈唑胺和替加环素耐药的粪肠球菌。结论导致尿路感染的病原菌种类繁多,大肠埃希菌和粪肠球菌是主要病原菌,其耐药情况严重;为保证治疗的有效性,临床医生应注重相关病原学和药敏检查结果。     

Microbiological monitoring for the causative agents of nosocomial infections (exemplified by resuscitation and intensive therapy units)]

More than 900 isolates from at least 1500 patients were tested within 1996-1998. Gram-negative organisms were the main pathogens isolated from patients with different forms of nosocomial complications such as late pneumonia, associated with artificial ventilation of the lungs, and various secondary wound or urinary tract infections. The prevalence of Pseudomonas aeruginosa was stated. Antibioticograms showed that the most active drugs were imipenem (more than 90 per cent of the susceptible isolates) and ticarcillin/clavulanate (48-58 per cent of the susceptible isolates). The activity of ticarcillin/clavulanate (Timentin) was practically the same as that of imipenem against 21 strains of P.aeruginosa isolated from the blood and cerebrospinal fluid of 21 patients with sepsis and 3 patients with secondary purulent meningitis.     

Immune risk phenotype is associated with nosocomial lung infections in elderly in-patients

Background

Nosocomial infections are extremely common in the elderly and may be related to ageing of the immune system. The Immune Risk Phenotype (IRP), which predicts shorter survival in elderly patients, has not been evaluated as a possible risk factor for nosocomial infection. Our aim was to assess the prevalence of nosocomial infections in elderly in-patients and to investigate potential relationships between nosocomial infections and the immunophenotype, including IRP parameters.

Results

We included 252 consecutive in-patients aged 70 years or over (mean age, 85 ± 6.2 years), between 2006 and 2008. Among them, 97 experienced nosocomial infections, yielding a prevalence rate of 38.5% (95% confidence interval, 32.5-44.5). The main infection sites were the respiratory tract (21%) and urinary tract (17.1%) When we compared immunological parameters including cell counts determined by flow cytometry in the groups with and without nosocomial infections, we found that the group with nosocomial infections had significantly lower values for the CD4/CD8 ratio and naive CD8 and CD4 T-cell counts and higher counts of memory CD8 T-cells with a significant increase in CD28-negative CD8-T cells. Neither cytomegalovirus status (positive in 193/246 patients) nor presence of the IRP was associated with nosocomial infections. However, nosocomial pneumonia was significantly more common among IRP-positive patients than IRP-negative patients (17/60 versus 28/180; p = 0.036).

Conclusion

Immunological parameters that are easy to determine in everyday practice and known to be associated with immune system ageing and shorter survival in the elderly are also associated with an elevated risk of nosocomial pneumonia in the relatively short term.     

阴沟肠杆菌感染的临床分布及耐药性变迁

目的:分析阴沟肠杆菌感染的临床分布及耐药性变迁,为临床合理用药提供指导。方法:采用临床微生物指南中的常规方法对医院各类标本进行分离培养,对医院近3年阴沟肠杆菌感染的临床分布及耐药性变迁情况进行总结分析。结果:2009年12月~2011年12月,从临床标本中共分离出165株阴沟肠杆菌,菌株的主要来源为痰液、尿液和其他分泌物,分别占50.3%、32.7%和27%;临床药物敏感试验结果显示,阴沟肠杆菌对头孢菌素类、青霉素类、氯霉素和氨基糖苷类的抗菌药物呈现较高的耐药率,对亚胺培南、头孢吡肟比较敏感,而头孢西丁、氨苄西林及头孢唑林对阴沟肠杆菌无效。结论:阴沟肠杆菌主要导致呼吸道和尿路感染,是一种对多种抗菌素耐药的高耐药性细菌,临床医生应结合临床药敏结果合理地选用抗菌药物,以减少耐药菌株的产生和蔓延。