Risk factors for antimicrobial resistance and influence of resistance on mortality in patients with bloodstream infection caused by Pseudomonas aeruginosa

This study was conducted to evaluate risk factors for antimicrobial resistance and influence of resistance on mortality in Pseudomonas aeruginosa bacteremia. Data on 190 patients with P. aeruginosa bacteremia were analyzed retrospectively. Antimicrobial resistance to antipseudomonal antibiotics was evaluated. The main outcome measure was 30-day mortality. In P. aeruginosa bacteremia, resistance rates to piperacillin (PIP), ceftazidime (CAZ), ciprofloxacin (CIP), and imipenem (IPM) were 29 (56/190), 19 (36/190), 17 (32/190) and 15% (28/190), respectively. Prior uses of fluoroquinolones or carbapenems were independent risk factors for resistance to CIP and IPM, and prior use of extended-spectrum cephalosporins was a risk factor for PIP-R. An indwelling urinary catheter was a risk factor for PIP-R, CAZ-R, and CIP-R. An invasive procedure was a risk factor for CIP-R and IPM-R. The 30-day mortality rate was 44% (33/75) in patients infected by strains resistant to any of the antipseudomonal antibiotics, but 33.9% (39/115) in those by strains susceptible to all antipseudomonal antibiotics (p = 0.161). Among patients with bloodstream infection due to antimicrobial-resistant P. aeruginosa, those infected by IPM-R strains had the highest mortality (IPM-R, 53.6% vs. CAZ-R, 47.2% vs. CIP-R 46.9%, PIP-R, 39.3%). In this study regarding P. aeruginosa bacteremia, prior uses of fluoroquinolones, carbapenems, or extended-spectrum cephalosporins, a prior invasive procedure, and an indwelling urinary catheter were found to be associated with antimicrobial resistance. The patients with bloodstream infection caused by antimicrobial-resistant P. aeruginosa, especially to imipenem, had a tendency toward higher mortality than those infected by susceptible strains.     

Impact of fluoroquinolone use on multidrug-resistant bacteria emergence

During the last two decades, fluoroquinolone use has significantly increased in Europe and in the USA. This could be explained by the arrival of newer fluoroquinolones with antipneumoccal activity. Increased use of fluoroquinolones is associated with higher rates of bacterial resistance to these antibiotics. Resistance of Gram-negative bacilli to fluoroquinolones is increasing in industrialized countries. In addition, fluoroquinolone use has been identified as a risk factor for colonization and infection to methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumanni, extending-spectrum beta-lactamase producing Gram negative bacilli, and multidrug-resistant bacteria. Nosocomial infections due to multidrug-resistant bacteria are associated with higher mortality and morbidity rates. This could be related to more frequent inappropriate initial antibiotic treatment in these patients. Limiting the use of fluoroquinolones, limiting the duration of treatment with fluoroquinolones, and using appropriate dosage of these antibiotics could be suggested to reduce resistance to these antibiotics and to reduce the emergence of multidrug-resistant bacteria.     

Low-level resistance to fluoroquinolones conferred by efflux overproduction in Pseudomonas aeruginosa: clinical significance and routine detection

The aim of this study was (i) to assess the impact of stable overproduction of efflux systems MexAB-OprM and MexXY-OprM on the bacteriostatic activities of fluoroquinolones in clinical Pseudomonas aeruginosa strains and (ii) to find a convenient test for screening isolates with a low level resistance to fluoroquinolones. The minimal inhibitory concentrations (MICs) of ciprofloxacin and levofloxacin were determined for clinical isolates of P. aeruginosa overexpressing MexAB-OprM or MexXY-OprM. Efflux pumps derepression was associated with a modest two- to fourfold increase in resistance to the tested fluoroquinolones. Clinical significance of low level resistance conferred by the efflux mechanism was evaluated with a Monte Carlo simulation with various fluoroquinolone regimens. With this model, low levels of resistance to ciprofloxacin (MIC > or =0.25 mg/L) or levofloxacin (MIC > or =1 mg/L) such as those due to overproduced MexAB-OprM or MexXY-OprM were predicted to result in poor clinical outcomes. Altogether these data strongly suggest that when derepressed MexAB-OprM or MexXY-OprM provides P. aeruginosa with a resistance that may be sufficient to impair the efficacy of single therapy with highly potent fluoroquinolones such as ciprofloxacin and levofloxacin. Routine detection of clinical strains that displayed low-level resistance to fluoroquinolones with a Mueller Hinton agar containing 0.20 mg/L of ciprofloxacin will help clinician in his therapeutical choice.     

Which betalactam antibiotic use as a marker of multiresistance in Pseudomonas aeruginosa?

The determination of an indicating antibiotic for multiresistance, as methicillin in staphylococci, can be useful for Pseudomonas aeruginosa. Until now, the majority of the hygienists used ticarcillin, ceftazidim or imipenem in their investigations as markers of multiresistance for this species. Piperacillin has never been proposed for this purpose. To evaluate this choice, 2098 non-repetitive P. aeruginosa strains collected from 15 teaching hospitals in 1997-1999 were analysed, for eight antibiotics (ticarcillin, piperacillin, ceftazidim, imipenem, tobramycin, amikacin, ciprofloxacin, fosfomycin) according (i) to the results of the minimal inhibiting concentrations obtained by dilution in Mueller-Hinton agar, (ii) to their susceptibility following the criteria of Comité de l'antibiogramme de la Société Fran?aise de Microbiologie and (iii) to the determination of the mechanisms of resistance to the beta-lactam antibiotics. The low rates of sensitivity to the beta-lactam antibiotics, aminoglycosides, ciprofloxacin and fosfomycin were more frequent for piperacillin-resistant strains than for ceftazidim-resistant ones. Resistance to the other beta-lactam antibiotics are poor markers of multiresistance. In the light of the presented data, piperacillin seems to be, among the beta-lactam antibiotics, the best candidate as a marker of multiresistance for P. aeruginosa, followed by ceftazidim. This multiresistance is mainly found in strains overproducing AmpC cephalosporinase or transferable beta-lactamases. These mechanisms are well detected by resistance to piperacillin.     

天津地区某基层医院铜绿假单胞菌的5年耐药变迁

目的 观察天津地区某基层医院铜绿假单胞菌的临床分布及其耐药情况和近5年的耐药变化趋势,为临床抗感染治疗的经验用药和合理使用抗生素提供理论依据。方法 收集2013年1月~2017年12月我院住院患者细菌培养标本分离的铜绿假单胞菌,分析其科室分布及菌株对临床常用抗菌药物的耐药率和耐药变迁。结果 5年内共分离到铜绿假单胞菌542株,其分布主要以呼吸内科、ICU以及普通外科为主。铜绿假单胞菌对氨曲南、左氧氟沙星、头孢他啶、亚胺培南、美罗培南、哌拉西林他唑巴坦、阿米卡星的耐药率分别为28.80%、17.30%、15.40%、13.30%、15.30%、8.30%、3.60%。结论 铜绿假单胞菌是基层三级综合医院临床科室最常见的革兰阴性非发酵菌,分离人群主要以呼吸内科、ICU和普通外科为主。我院分离的铜绿假单胞菌对大多数临床常用抗菌药物均有较好的体外敏感性。因此,临床使用这些药物治疗铜绿假单胞菌感染通常可获得良好的疗效。但由于该细菌易产生获得性耐药,且近年来少数抗菌药物的耐药率波动范围较大。因此建议临床医生关注实验室药敏结果报告和细菌耐药监测报告。     

广州地区2003—2007年499株铜绿假单胞菌的耐药性分析

目的了解广州地区铜绿假单胞菌对常用抗菌药物的耐药状况,以指导临床合理选用抗生素。方法收集广州市7家三甲医院2003—2007年分离的499株铜绿假单胞菌,利用VITEK-32全自动微生物鉴定系统对所有收集的菌株进行种属鉴定,参照美国临床和实验室标准化协会（CLSI）推荐的方法,分别采用K—B法和琼脂稀释法进行药敏试验,用WHONET5．4软件分析铜绿假单胞菌的耐药性,用SPSS11．5软件进行统计分析。结果499株铜绿假单胞菌其抗生素耐药率依次为庆大霉素（42．0％）、阿米卡星（36．6％）、亚胺培南（32．8％）、头孢吡肟（28．3％）、头孢他啶（27．1％）、美罗培南（21．4％）、氨曲南（20．5％）、哌拉西林（8．8％）、哌拉西林／三唑巴坦（8．3％）、左旋氧氟沙星（8．1％）和环丙沙星（7．6％）;2003—2007年5年期间铜绿假单胞菌对亚胺培南的耐药率分别是27．7％、25．0％、31．6％、35．2％和34．3％,对美罗培南的耐药率分别是22．2％、21．O％、21．2％、19．7％和24．5％。结论2003—2007年广州地区铜绿假单胞菌整体耐药现象严重,对氨基糖苷类、碳青霉烯类和头孢菌素类抗生素高度耐药,仅对喹诺酮类和青霉素类抗生素较为敏感。因而加强其耐药性监测不仅可以指导临床合理选用抗菌药物．而且还能为临床提供最新的流行病学和耐药性变迁资料。     

Antimicrobial susceptibility pattern of clinical isolates of Pseudomonas aeruginosa in a tertiary care hospital.

BACKGROUND AND PURPOSE: Pseudomonas aeruginosa is an important cause of morbidity and mortality in hospitalized, critically ill patients and patients with underlying medical conditions such as cystic fibrosis, neutropenia, and iatrogenic immunosuppression. The prevalence of multiresistant P. aeruginosa isolates has been increasing. The aim of this study was to determine the antimicrobial susceptibility patterns in P. aeruginosa strains isolated at a university teaching hospital in Kuala Lumpur, Malaysia. METHODS: The Laboratory Information System of the microbiology department was retrospectively reviewed to determine the susceptibility patterns of P. aeruginosa isolates to anti-pseudomonal antibiotics, from January to June 2005. Disk diffusion methods were employed and results were interpreted according to National Committee for Clinical Laboratory Standards guidelines. RESULTS: 505 clinical isolates of P. aeruginosa were tested. Major sources of these isolates included respiratory tract, wound, urine and blood. The rates of antimicrobial resistance of isolates were 6.73% to amikacin, 12.9% to gentamicin, 10.1% to netilmicin, 10.9% to ceftazidime, 11.3% to ciprofloxacin, 9.9% to imipenem, 10.8% to piperacillin, 9.4% to piperacillin-tazobactam and 0% to polymyxin B. Of the 505 isolates, 29 (5.74%) were found to be multidrug-resistant; these were most commonly isolated from respiratory tract specimens of patients in surgical units, followed by respiratory tract specimens in patients in medical units. CONCLUSIONS: The data in this study showed low rates of antibiotic resistance among P. aeruginosa isolates. Combinations of aminoglycosides plus beta-lactams or quinolones should be the appropriate choice for empirical therapy in P. aeruginosa infections. Active antibiotic susceptibility testing and surveillance should be continued in order to curtail the problem of antibiotic resistance.     

Effect of β-lactam antibiotics on the in vitro development of resistance in Pseudomonas aeruginosa

Objective   To investigate whether stepwise selection of resistance mutations may mirror the continued bacterial exposure to antibiotics that occurs in the clinical setting.
Methods   We examined the in vitro development of resistance to a number of commonly used antibiotics (cefepime, cefpirome, ceftazidime, cefotaxime, piperacillin and imipenem) in Pseudomonas aeruginosa , a significant nosocomial pathogen. Stepwise resistance was assessed by serial passage of colonies located nearest to the inhibition zone on antibiotic-containing gradient plates.
Results   The lowest frequencies of spontaneous resistance mutations were found with cefepime and imipenem; these drugs also resulted in the slowest appearance of resistance of spontaneous resistance mutations. In five wild-type P. aeruginosa strains, cefepime-selected isolates required a mean of 30 passages to reach resistance; resistance occurred more rapidly in strains selected with other cephalosporins. P. aeruginosa strains that produced β -lactamase or non-enzymatic resistance generally developed resistance more rapidly than wild-type strains. For most strains, resistance to all antibiotics except imipenem correlated with increased levels of β -lactamase activity. Cross-resistance of cephalosporin-selected resistant mutants to other cephalosporins was common. Cephalosporin-resistant strains retained susceptibility to imipenem and ciprofloxacin.
Conclusions   From our in vitro study, we can conclude that the rate of development of resistance of P. aeruginosa is lower with cefepime compared with other cephalosporines.     

The emergence of antibiotic resistance by mutation

The emergence of mutations in nucleic acids is one of the major factors underlying evolution, providing the working material for natural selection. Most bacteria are haploid for the vast majority of their genes and, coupled with typically short generation times, this allows mutations to emerge and accumulate rapidly, and to effect significant phenotypic changes in what is perceived to be real-time. Not least among these phenotypic changes are those associated with antibiotic resistance. Mechanisms of horizontal gene spread among bacterial strains or species are often considered to be the main mediators of antibiotic resistance. However, mutational resistance has been invaluable in studies of bacterial genetics, and also has primary clinical importance in certain bacterial species, such as Mycobacterium tuberculosis and Helicobacter pylori, or when considering resistance to particular antibiotics, especially to synthetic agents such as fluoroquinolones and oxazolidinones. In addition, mutation is essential for the continued evolution of acquired resistance genes and has, e.g., given rise to over 100 variants of the TEM family of beta-lactamases. Hypermutator strains of bacteria, which have mutations in genes affecting DNA repair and replication fidelity, have elevated mutation rates. Mutational resistance emerges de novo more readily in these hypermutable strains, and they also provide a suitable host background for the evolution of acquired resistance genes in vitro. In the clinical setting, hypermutator strains of Pseudomonas aeruginosa have been isolated from the lungs of cystic fibrosis patients, but a more general role for hypermutators in the emergence of clinically relevant antibiotic resistance in a wider variety of bacterial pathogens has not yet been proven.     

我院重症监护室铜绿假单胞菌感染趋势及其耐药性分析

目的铜绿假单胞菌（Pseudomonas aeruginosa,PA）为院内感染的重要代表菌及临床分离率较高的菌株,在我院PA占所有菌株检出率的24.5%、占革兰阴性杆菌检出率的35.4%。通过对我院2006年1月-2009年6月期间4个重症监护室铜绿假单胞菌的感染情况及其耐药性进行分析,并与同期非重症监护室的病区进行比较,分析PA产碳青霉烯酶水解碳青霉烯类抗生素后同时携带多种耐药基因对其他药物敏感性的影响。方法采用Micro Scan全自动细菌鉴定和药敏分析仪,数据的分析采用WHONET软件。结果 4年间我院重症监护室铜绿假单胞菌检出数为559株,依次为：内科ICU272株、外科ICU149株、急诊ICU126株、儿科ICU12株。药敏结果显示：铜绿假单胞菌对大部分抗生素的敏感性呈逐年下降的趋势,尤其是重症监护室感染菌株。PA对碳青霉烯类抗菌素耐药的菌株产生多重甚至广泛耐药的几率较高。结论 4年间我院重症监护室铜绿假单胞菌对抗生素的耐药状况严重,尤其对头孢菌素,氨基糖苷类抗生素耐药率明显增加。对亚胺培南的耐药株同时携带多种耐药机制,产生多重耐药甚至泛耐药。多重耐药株和泛耐药株的检出亦呈逐年上升的趋势。     

Inhibition of adherence of mucoid Pseudomonas aeruginosa by alginase, specific monoclonal antibodies, and antibiotics.

The adherence of pseudomonal species was investigated by using a newly developed radiometric dacron fiber microcolumn assay. Pseudomonas aeruginosa, P. stutzeri, and Xanthomonas maltophilia were more adherent (approximately 20%) than P. pseudomallei, P. fluorescens, and P. cepacia (approximately 10%). Mucoid strains of P. aeruginosa were consistently more adherent than nonmucoid strains (30% versus 20%). Alginase was shown to inhibit the adherence of mucoid but not nonmucoid P. aeruginosa. Monoclonal antibodies to alginate were also shown to inhibit the adherence of mucoid but not nonmucoid P. aeruginosa. In addition, antibiotics active against P. aeruginosa were shown to inhibit the adherence of both mucoid and nonmucoid strains. Furthermore, synergism between dyadic combinations of monoclonal antibodies and antibiotic (ciprofloxacin), as well as alginase and antibiotic, was also observed. These results indicate that bacterial alginate has an intrinsic role in the adherence of mucoid P. aeruginosa and may have evolved not only for protection against dehydration in the water and soil ecosystem of this bacterium, but also as a means of attaching to soil substrates in the same ecosystem to enhance survival. They also suggest that synergistic combinations of antibiotics with alginase or monoclonal antibodies to alginate may be of value in the therapy of some pseudomonal infections.     

铜绿假单胞菌phoQ基因敲除对氨基糖苷类抗生素耐药性的影响

目的 分析氨基糖苷类抗生素敏感或耐药铜绿假单胞菌菌株二元信号系统PhoQ/PhoP编码基因序列并确定该系统与耐约性关系.方法 采用PCR获得铜绿假单胞菌菌株全长phoQ和phoP基因片段,T-A克隆后测序.构建phoQ和phoP基因原核表达系统,Ni-NTA亲和层析法提纯目的 重组表达产物rPhoQ和rPhoP,皮内注射免疫法制备兔抗血清,免疫双扩散法测定抗血清效价.采用Red重组系统敲除氨基糖苷类抗生素耐药铜绿假单胞菌菌株phoQ基因,采用PCR、测序和Western blot对phoQ突变株进行鉴定.采用试管稀释法测定各铜绿假单胞菌野生株和突变株对4种氨基糖苷类抗生素的最低抑菌浓度(MIC).结果 与GenBank中相关序列比较,所克隆的phoP和phoQ基因核苷酸和氨基酸相似性分别为98.7%～99.6%和98.7～100%、98.4%～99.8%和99.1%～100%.采用pET-42a和E. coli BL21DE3系统成功地表达了rPhoQ和rPhoP.rPhoQ和rPhoP兔抗血清免疫双扩效价分别为1:4和1:8抗血清.经PCR、测序和Western blot鉴定,两株phoQ突变株phoQ基因及产物均缺失.上述phoQ突变株对4种氨基糖苷类抗生素的MIC值分别为其野生株的1/512～1/2048.结论 PhoQ/PhoP是序列保守的铜绿假单胞菌二元信号转导系统,该系统介导细菌对氨基精苷类抗生素的耐药性.     

铜绿假单胞菌phoQ基因敲除对氨基糖苷类抗生素耐药性的影响

目的 分析氨基糖苷类抗生素敏感或耐药铜绿假单胞菌菌株二元信号系统PhoQ/PhoP编码基因序列并确定该系统与耐约性关系.方法 采用PCR获得铜绿假单胞菌菌株全长phoQ和phoP基因片段,T-A克隆后测序.构建phoQ和phoP基因原核表达系统,Ni-NTA亲和层析法提纯目的 重组表达产物rPhoQ和rPhoP,皮内注射免疫法制备兔抗血清,免疫双扩散法测定抗血清效价.采用Red重组系统敲除氨基糖苷类抗生素耐药铜绿假单胞菌菌株phoQ基因,采用PCR、测序和Western blot对phoQ突变株进行鉴定.采用试管稀释法测定各铜绿假单胞菌野生株和突变株对4种氨基糖苷类抗生素的最低抑菌浓度(MIC).结果 与GenBank中相关序列比较,所克隆的phoP和phoQ基因核苷酸和氨基酸相似性分别为98.7%～99.6%和98.7～100%、98.4%～99.8%和99.1%～100%.采用pET-42a和E. coli BL21DE3系统成功地表达了rPhoQ和rPhoP.rPhoQ和rPhoP兔抗血清免疫双扩效价分别为1:4和1:8抗血清.经PCR、测序和Western blot鉴定,两株phoQ突变株phoQ基因及产物均缺失.上述phoQ突变株对4种氨基糖苷类抗生素的MIC值分别为其野生株的1/512～1/2048.结论 PhoQ/PhoP是序列保守的铜绿假单胞菌二元信号转导系统,该系统介导细菌对氨基精苷类抗生素的耐药性.     

Induction of resistance to fluoroquinolones in clinical and environmental isolates of Pseudomonas aeruginosa

An attempt to induce resistance to ciprofloxacin in vitro was made against clinical and environmental isolates of Pseudomonas aeruginosa. This in vitro manipulation of strains resulted in the increase of minimum inhibitory concentration from 0.4 microg/ml to 1 microg/ml of the original strains to 9.0 to 12.5 microg/ml indicating development of resistance to ciprofloxacin and a major decrease in the size of zone diameters of norfloxacin and ofloxacin indicating cross resistance to these agents. Results indicate the induced resistance to ciprofloxacin can promote development of cross resistance to other fluoroquinolones. This suggests that caution should be taken while using fluoroquinolones for the treatment of Pseudomonas aeruginosa infections.     

Tigecycline: in-vitro performance as a predictor of clinical efficacy

The incidence of nosocomial disease caused by Gram-negative pathogens is increasing, and infections caused by Enterobacter, Klebsiella, Acinetobacter, Escherichia coli and Pseudomonas aeruginosa are more commonly refractive to traditional antimicrobial agents, including aminoglycosides, fluoroquinolones and broad-spectrum cephalosporins. The most important mechanism of resistance to beta-lactam antibiotics among Gram-negative bacilli involves the production of beta-lactamases. Extended-spectrum beta-lactamases are particularly worrisome, since they are often associated with multidrug resistance phenotypes, which can pose a significant therapeutic challenge. Novel agents for the treatment of Gram-negative infections are uncommon, as recent emphasis has been placed on the development of agents targeting drug-resistant strains of Gram-positive bacteria, e.g., streptococci, enterococci and staphylococci. Tigecycline, a semi-synthetic derivative of minocycline, has a unique and novel mechanism of action, which not only allows this agent to overcome the well-known tet gene-encoded resistance mechanisms, but also maintains its activity against Gram-negative pathogens producing a broad array of extended-spectrum beta-lactamases. Tigecycline is the first example of a new class of glycylcyclines with activity against a wide range of clinically important Gram-negative pathogens. Tigecycline has potent antimicrobial activity, and has been associated with an excellent therapeutic response in animal infection models and recently reported clinical trials, which reflect the effectiveness of tigecycline against pathogens causing intra-abdominal, skin and soft-tissue infections, including susceptible or multidrug-resistant strains of most Enterobacteriaceae, as well as anaerobic pathogens.     

Comparative sensitivity and resistance of some strains of Pseudomonas aeruginosa and Pseudomonas stutzeri to antibacterial agents

A comparison has been made of the sensitivities to various antibiotic and non-antibiotic substances of some strains of Pseudomonas aeruginosa and P. stutzeri, the latter including strains isolated from eye and other cosmetic products and from other sources. Whereas P. aeruginosa strains showed a high resistance to cetrimide and to benzalkonium chloride, the P. stutzeri strains were generally more sensitive to these and to chlorhexidine. The P. stutzeri strains were also more sensitive to the various antibiotics tested. The loss of the ability to transfer an R factor by two strains of P. aeruginosa caused no significant change in their drug sensitivity pattern.     

铜绿假单胞菌的GM-PFGE分型的研究

目的研究全基因组ＤＮＡ稀有位点限制性内切酶酶切脉冲电场电泳图谱（ＧＭ－ＰＦＧＥ）在铜绿假单胞菌基因分型中的应用,并与表型分型比较。方法对１个月内来自两个医院的病人及环境的２０株铜绿假单胞菌进行了ＧＭ－ＰＦＧＥ图谱分析,同时进行３０种生化反应的统计分型、２３种药物的敏感性分型、胞外脂多糖的血清抗原分型;并利用数值分类软件包进行相关性比较研究。结果临床致病铜绿假单胞菌的生化表型基本稳定,但其药物抗性的获得与丢失较为明显。血清型、生化性状及药物抗性之间无明显对应关系。当２菌株ＧＭ－ＰＦＧＥ图谱条带相似系数大于８０％时,为同一菌株的不同克隆亚型,当相似系数在２５％～７０％之间时,则为不同菌株。结论ＧＭ－ＰＦＧＥ分析可显示染色体结构的区域多型性,其重复性好,分辨率明显高于表型分型,结果可靠,必将成为铜绿假单胞菌或其它病原微生物分子流行病学研究的有力工具。     

2014~2018年某三甲医院产生物膜铜绿假单胞菌耐药性及患者临床特征分析

目的 分析某三级甲等医院分离的产生物膜铜绿假单胞菌耐药性及患者的临床特征。方法 收集2014~2018年某三甲医院临床分离的产生物膜铜绿假单胞菌,进行菌种鉴定、抗菌药物敏感性试验并对药物的耐药率进行分析;收集患者的临床资料,并对感染患者临床特征进行分析。结果 2014~2018年临床分离的423株产生物膜铜绿假单胞菌均来自下呼吸道标本,来源以呼吸内科为主,年龄＞60岁、合并有支气管扩张等肺部基础疾病的患者易引起产生物膜铜绿假单胞菌的感染;2015~2018年产生物膜铜绿假单胞菌对亚胺培南、美罗培南的耐药率逐年下降。结论 产生物膜铜绿假单胞菌对碳青霉烯类抗生素及氨基糖苷类抗生素耐药率较低,低于非产生物膜的铜绿假单胞菌,临床微生物学实验室应选用可靠的药敏方法和合适的培养时间,为临床医生提供准确的药敏结果。     

Epidemiology of Pseudomonas aeruginosa hospital infection in the Ivory Coast

210 P. aeruginosa hospital strains isolated at Abidjan from pathological samples or contaminated material were studied by means of serotyping, biotyping, phage-typing and for their resistance to eleven antibiotics. 87% were classified into 14 serogroups: O:1, O:2, O:3, O:4, O:5, O:6, O:8, O:9, O:10, O:11, O:12, O:13, O:15, O:16. No strains were O:7 or O:14. The presence of an ortho-nitrophenyl beta-d-galactopyranoside hydrolase was demonstrated in 42 strains belonging to the serogroup O:11. Sixty-five phage-types were defined but 37% of strains were untypable by phages. The incidence of resistance to each tested antibiotic was as follows: carbenicillin 49%, mezlocillin 44%, ticarcillin 34%, azlocillin 25%, cefamandole 94%, latamoxef 15%, cefotaxime 41%, cefsulodin 32%, tobramycin 35%, amikacin 7%, gentamicin 39%. Thirty-eight strains were multiresistant to carbenicillin, mezlocillin, ticarcillin, azlocillin, and four strains to eleven antibiotics. These results are compared with data of the scientific literature on the epidemiology of hospital Pseudomonas infection.     

产ESBLs、AmpC、KPC酶的葡萄糖不发酵细菌的耐药性分析及临床分布

目的了解本地区葡萄糖不发酵细菌中泛耐药菌（代表株铜绿假单胞菌、鲍曼不动杆菌、嗜麦芽窄食单胞菌）在临床标本中的分离与耐药情况,为临床合理使用抗生素提供指导。方法对临床分离的180株葡萄糖不发酵细菌进行分类鉴定和药敏试验,并用纸片扩散法筛选出产超广谱β-内酰胺酶（ESBLs）、头孢菌素酶（AmpC酶）及碳青霉烯类水解酶（KPC酶）的耐药菌株。结果在葡萄糖不发酵细菌的构成比中,其中产超广谱β-内酰胺酶（ESBLs）56株（31.1%）,产AmpC酶22株（12.2%）,KPC酶2株（1.1%）;同时产ESBLs和AmpC酶16株（8.9%）,同时产ESBLs、AmpC、KPC酶1株（0.6%）。3种主要葡萄糖不发酵细菌对头孢他啶、头孢三嗪、头孢噻肟、哌拉西林的耐药率最高,其中铜绿假单胞菌对阿米卡星、左氧氟沙星、环丙沙星耐药率较低,鲍曼不动杆菌对亚胺培南、左氧氟沙星耐药率较低,嗜麦芽窄食单胞菌对复方新诺明、环丙沙星耐药率较低。结论葡萄糖不发酵细菌中泛耐药菌特别是铜绿假单胞菌、鲍曼不动杆菌、嗜麦芽窄食单胞菌均有较高的多重耐药性,临床上应重视葡萄糖不发酵细菌引起的感染,根据药敏试验结果合理使用抗生素。