铜绿假单胞菌临床分离株耐药性研究

目的：了解铜绿假单胞菌的耐药性为临床治疗提供依据。方法：用K-B法检测铜绿假单胞菌对10种抗菌药物的敏感率。结果：铜绿假单胞菌对亚胺培南等碳青酶烯类药物在内均有很高耐药性。结论：铜绿假单胞菌对多种抗菌药物的耐药率较高，临床应加强对铜绿假单胞菌的监控并防治耐药菌株的传播流行。     

儿童患者中对碳青霉烯类耐药的绿脓假单胞菌产金属酶基因型研究

目的研究儿童患者中对碳青霉烯类抗生素耐药的绿脓假单胞菌产金属酶的基因型。方法本研究收集了2003年12月至2005年11月我院住院患儿中分离出的对碳青霉烯类抗生素耐药的绿脓假单胞菌59株。使用E试验法检测产金属酶的耐药表型，PCR技术检测编码金属酶的IMP、VIM、SPM和GIM4种基因型。PCR反应产物进行纯化后，使用双脱氧末端终止法进行DNA测序。将得到的拼接序列与GenBank中Blast进行同源分析，确定其基因亚型。结果59株对碳青霉烯类抗生素耐药的绿脓假单胞菌中，纸片法检测金属酶表型结果阳性29株，占49．2％。PCR检测金属酶基因型阳性39株，占66．1％，其中IMP型阳性35株，占89．7％，VIM型阳性4株，占10．3％。未检测出SPM和GIM型金属酶。测序结果显示，IMP型测序结果均为产IMP．1亚型金属酶的绿脓假单胞菌。VIM型测序结果均为产VIM-2亚型金属酶的绿脓假单胞菌。结论儿童患者中对碳青霉烯类抗生素耐药的绿脓假单胞菌，产金属酶率高于成人报道。产生的金属酶同时存在IMP-1和VIM-2两种基因型，其中以IMP-1亚型为主，少部分为VIM-2亚型。产金属酶是儿童患者对碳青霉烯类抗生素耐药的绿脓假单胞菌的重要耐药机制。在儿科进行对碳青霉烯类耐药的绿脓假单胞菌产金属酶的监测十分重要。     

深圳地区三级区属医院铜绿假单胞菌感染分布及耐药性分析

目的 了解深圳市龙华和光明新区三家三级区属医院铜绿假单胞菌感染的临床分布特征及耐药性,为临床科学用药提供依据。方法 收集2013年6月～2014年11月三家三级区属医院各科住院临床标本共3 176份,采用梅里埃VITEK-32细菌鉴定仪进行细菌鉴定,铜绿假单胞菌阳性标本采用K-B法和微量肉汤稀释法(MIC法)进行药敏试验,并对检验结果进行统计学处理。结果 3176份标本铜绿假单胞菌总分离率为51.16%(1 625/3 176),其中痰标本为52.8%(858/1 625),其次为支气管肺泡灌洗液和脓液分别为20.1%(327/1 625)和16.7%(271/1 625)。病区主要分布在ICU、心胸外科和神经外科,分别为41.6%(676/1 625),15.9%(259/1 625)和19.1%(310/1 625)。碳青霉烯类敏感、耐碳青霉烯类和泛耐药铜绿假单胞菌分离率分别为67.1%(1 090/1 625),31.6%(514/1 625)和1.29%(21/1 625)。耐碳青霉烯类铜绿假单胞菌的耐药性较碳青霉烯类敏感的严重,除多黏菌素B外两者耐药率比较差异有统计学意义(χ²=12.617～80.654,P＜0.05～0.001),2例耐碳青霉烯类铜绿假单胞菌对多黏菌素B耐药,除阿米卡星、庆大霉素、妥布霉素有较高的敏感度外,其余11种抗菌药物的耐药率均＞60%以上。结论 临床上铜绿假单胞菌有很高的分离率,主要来源于呼吸道和ICU病区。耐碳青霉烯类铜绿假单胞菌比碳青霉烯敏感的耐药严重,应密切关注耐碳青霉烯铜绿假单胞菌耐药性发展,采取有效的预防传播与感染措施,科学使用抗菌药,杜绝耐碳青霉烯类和泛耐药铜绿假单胞菌的蔓延。     

75株碳青霉烯类耐药铜绿假单胞菌ERIC-PCR菌种分型及其主要耐药机制研究

目的探讨碳青霉烯类耐药的铜绿假单胞菌同源性及其主要耐药机制。方法收集临床标本946份,分离出碳青霉烯类耐药的铜绿假单胞菌,采用琼脂稀释法进行体外药物敏感性试验;采用肠杆菌基因间重复一致序列为引物的聚合酶链反应(ERIC-PCR)进行耐药菌株同源性分析;筛选其金属β-内酰胺酶并测定主动外排系统表型来分析碳青霉烯类耐药的铜绿假单胞菌的耐药性。结果共检测出75株碳青霉烯类耐药的铜绿假单胞菌;ERIC-PCR同源性分析显示75株菌株共分为8个型别,其中A型占34.7%(26株)、B型占22.7%(17株);75株碳青霉烯类耐药的铜绿假单胞菌中有13株为产酶株,产酶率为17.3%;外排泵抑制剂MC207110可以使34株美罗培南耐药株的最低抑菌浓度(MIC)较单药时下降4倍或以上,占63.0%。结论本院分离的耐碳青霉烯类铜绿假单胞菌主要有两种类型,产生碳青霉烯水解酶和外排泵机制是碳青霉烯类耐药铜绿假单胞菌耐药的重要机制。     

75株碳青霉烯类耐药铜绿假单胞菌的检出及药敏分析

目的 探讨碳青霉烯类耐药铜绿假单胞菌的耐药性及分布状况.方法 对本院2009年1～8月送检标本中共分离到的946株病原菌,进行细菌培养和药敏试验结果分析.结果 946株病原菌中铜绿假单胞菌有171株,占18.1％,其中碳青霉烯类耐药铜绿假单胞菌75株,其对碳青霉烯类抗生素的耐药率为43.9％.痰标本中检出碳青霉烯类耐药铜绿假单胞菌43株,占57.3％.75株碳青霉烯类耐药铜绿假单胞菌的病区分布以重症监护病房为主,占33.3％.结论 铜绿假单胞菌感染的标本以呼吸道痰液为主,病区分布主要集中在重症监护病房和神经外科等病室.     

耐碳青酶烯铜绿假单胞菌的分布及耐药分析

目的了解耐碳青酶烯铜绿假单胞菌的分布及耐药分析,为临床合理使用抗菌药物及医院感染的防控提供依据方法对该院2015年1月到2017年12月临床分离的耐碳青酶烯铜绿假单胞菌的分布及药敏情况作回顾性分析。结果耐碳青酶烯铜绿假单胞菌的检出以痰标本为主,占90.85%;主要分布在ICU病房、呼吸内科等科室;耐碳青酶烯铜绿假单胞菌对阿米卡星的耐药率较低,为14.5%～30.5%,对其他抗菌药物呈不同程度的耐药;耐碳青酶烯铜绿假单胞菌对常用的抗菌药物的耐药率明显高于非耐碳青酶烯铜绿假单胞菌。结论临床医生应加强对耐碳青酶烯铜绿假单胞菌的耐药监测,合理使用抗生素。     

耐碳青霉烯类铜绿假单胞菌的耐药机制

目的探讨该院耐碳青霉烯类铜绿假单胞菌的耐药机制。方法采用ATB Expression进行细菌鉴定和药物敏感试验。应用PCR法对耐碳青霉烯类铜绿假单胞菌耐药基因IMP、VIM和外膜孔蛋白基因OprD2进行检测。结果 70株耐碳青霉烯类铜绿假单胞菌对多黏菌素、阿米卡星、庆大霉素耐药率分别为1.4%、47.1%、65.7%,对头孢他啶、头孢吡肟、环丙沙星的耐药率分别为64.3%、60.3%、71.4%;70株耐碳青霉烯类铜绿假单胞菌中,IMP阳性30株(42.9%)、VIM阳性13株(17.6%),膜微孔蛋白OprD2缺失70株(100.0%)。结论耐碳青霉烯类铜绿假单胞菌多重耐药情况严重。外膜孔蛋白基因OprD2的缺失是该院铜绿假单胞菌耐碳青霉烯类抗菌药物的主要机制。     

铜绿假单胞菌碳青霉烯耐药的机制研究

目的分析159株临床分离的非重复碳青霉烯耐药铜绿假单胞菌对抗菌药物的耐药性,探究体外联合药敏试验对碳青霉烯耐药铜绿假单胞菌表现不同作用的机制。方法收集来自不同患者的铜绿假单胞菌159株,亚胺培南及美罗培南耐药。采用三维水解试验检测β-内酰胺酶、聚合酶链式反应(PCR)等方法检测多重耐药菌可能存在的耐药机制。结果 159株临床分离的非重复碳青霉烯耐药铜绿假单胞菌,通过三维实验检测,其中15株产MBL、13株产AmpC酶。体外联合药物敏感试验,加入MC-207,110后约38%的菌株对碳青霉烯类抗生素的MIC下降4个梯度。检测试验菌株,21株携带IMP基因,18株携带ampC基因;检测OprD2通道蛋白,159株中约有48%的菌株OprD2丢失。结论北京友谊医院碳青霉烯耐药铜绿假单胞菌对碳青霉烯类抗生素耐药的主要原因不是IMP、AmpC水解酶;碳青霉烯耐药铜绿假单胞菌对碳青霉烯类抗生素耐药的重要原因可能是外排泵及外膜孔道蛋白。     

铜绿假单胞菌对碳青霉烯类抗生素的耐药机制——耐药株外膜蛋白OprD2缺失

目的：研究铜绿假单胞菌对碳青霉烯类抗生素的耐药机制。方法：以亚胺培南为代表,应用十二烷酸磺酸钠-聚丙烯酰胺凝胶电泳(SDSPAGE)外膜蛋白图谱、凝胶分光光度扫描分析方法,分别研究临床分离的铜绿假单胞菌亚胺培南耐药株和亚胺培南敏感株。结果：耐药组OprD2相对含量显低于敏感组。结论：OprD2的缺失是铜绿假单胞菌对以亚胺培南为代表碳青霉烯类抗生素耐药的主要原因。     

铜绿假单胞菌耐药监测

目的：调查2002年1月至2002年12月本院铜绿假单胞菌感染患者铜绿假单胞菌对常用抗菌药物的敏感性。方法：采用美国德灵公司Oade Microscan Autoscan-4自动分析系统进行菌株鉴定及药物敏感性测试。结果：分离出86株铜绿假单胞菌临床分离株，其药物敏感度依次为亚胺培南81．4％，哌拉西林-三唑巴坦76．7％，哌拉西林70．9％，阿米卡星66．3％，头孢他啶57．6％，妥布霉素57％，头孢吡肟51．2％，环丙沙星50％，头孢曲松45．2％，庆大霉素44％，氨曲南39．3％和头孢噻肟36．9％。与2000年比较，铜绿假单胞菌对环丙沙星耐药率由2000年的29．3％上升为2002年的45．1％，对妥布霉素的耐药率2000年为28．7％，2002年为39．5％，对其余抗菌药物耐药率无明显变化。结论：铜绿假单胞菌仅对碳青霉烯类、酰脲类青霉素类、氨基糖苷类、第三、四代头孢菌素和氟喹诺酮类保持较高敏感性。铜绿假单胞菌对环丙沙星及妥布霉素的敏感性与2000年比较明显下降。     

In vitro activity of azthreonam, a monobactam antibiotic.

We studied the activity of azthreonam (SQ 26,776), a novel monocyclic beta-lactam compound, against a variety of clinical isolates. It was more potent than moxalactam, cefoperazone, cefamandole, cefoxitin, ticarcillin, tobramycin, or amikacin against strains of Klebsiella spp., Serratia spp., and the Proteus group. It was highly effective against Escherichia coli and strains of Salmonella spp. The median minimal inhibitory concentration for all species of Enterobacteriaceae was less than or equal to 2 micrograms/ml. Azthreonam was moderately active against Pseudomonas aeruginosa, including tobramycin-resistant strains, and against Pseudomonas cepacia (median minimal inhibitory concentration, 16 to 32 micrograms/ml), but was weakly active against Pseudomonas maltophilia and strains of Acinetobacter spp. and Achromobacter spp. The drug showed little activity against Staphylococcus aureus, enterococci, and anaerobic bacteria, including Bacteroides fragilis, Clostridium spp., and gram-positive cocci. Like moxalactam and cefoperazone, azthreonam exhibited a considerable inoculum effect with strains of Enterobacter spp. and Pseudomonas spp. Combination with clavulanic acid did not increase the activity of azthreonam against S. aureus but was synergistic for 5 of 15 strains of B. fragilis. Azthreonam is about 50% bound to human serum protein. The selective range of activity of this compound could be of clinical benefit.     

In vitro antimicrobial activity evaluation of cefodizime (HR221), a new semisynthetic cephalosporin.

Cefodizime (HR221) is a new alpha-methoxyimino cephalosporin developed by Hoechst-Roussel with a reported serum half-life of over 2 h. In vitro susceptibility studies showed that the cefodizime spectrum includes all those Enterobacteriaceae, staphylococci, Streptococcus spp., Haemophilus spp., and Neisseria spp. normally susceptible to cefotaxime (HR756) or ceftizoxime (FK749) or both. Cefodizime was less active (two- to eightfold) than cefotaxime or ceftizoxime against some enteric species, but was the most potent drug against some strains of Morganella spp. and Proteus vulgaris. Enterococci, methicillin-resistant Staphylococcus aureus, and most Pseudomonas spp. were resistant to cefodizime (median minimum inhibitory concentrations, greater than or equal to 64 microgram/ml). Acinetobacter spp. and Pseudomonas aeruginosa strains required cefodizime concentrations of 32 microgram/ml to inhibit 50% of tested strains. Cefodizime was very stable to hydrolysis by Richmond-Sykes type I, II, III, and IV beta-lactamases, as well as the enzyme derived from Bacillus cereus. The reference PADAC and nitrocefin substrate hydrolysis by a type I beta-lactamase was markedly inhibited (greater than 80%) by cefodizime at concentrations 0.4 to 4% of substrate concentration. Cefodizime was active against 43% of bacteria which were resistant to cephalothin and cefamandole and against 58% of those resistant to aminoglycosides.     

Species identification of corynebacteria by cellular fatty acid analysis

We evaluated the usefulness of cellular fatty acid analysis for the identification of corynebacteria. Therefore, 219 well-characterized strains belonging to 21 Corynebacterium species were analyzed with the Sherlock System of MIDI (Newark, DE). Most Corynebacterium species have a qualitative different fatty acid profile. Corynebacterium coyleae (subgroup 1), Corynebacterium riegelii, Corynebacterium simulans, and Corynebacterium imitans differ only quantitatively. Corynebacterium afermentans afermentans and C. coyleae (subgroup 2) have both a similar qualitative and quantitative profile. The commercially available database (CLIN 40, MIDI) identified only one third of the 219 strains correctly at the species level. We created a new database with these 219 strains. This new database was tested with 34 clinical isolates and could identify 29 strains correctly. Strains that remained unidentified were 2 Corynebacterium aurimucosum (not included in our database), 1 C. afermentans afermentans, and 2 Corynebacterium pseudodiphtheriticum. Cellular fatty acid analysis with a self-created database can be used for the identification and differentiation of corynebacteria.     

In vitro antibacterial properties of pexiganan, an analog of magainin

Pexiganan, a 22-amino-acid antimicrobial peptide, is an analog of the magainin peptides isolated from the skin of the African clawed frog. Pexiganan exhibited in vitro broad-spectrum antibacterial activity when it was tested against 3,109 clinical isolates of gram-positive and gram-negative, anaerobic and aerobic bacteria. The pexiganan MIC at which 90% of isolates are inhibited (MIC90) was 32 micrograms/ml or less for Staphylococcus spp., Streptococcus spp., Enterococcus faecium, Corynebacterium spp., Pseudomonas spp., Acinetobacter spp., Stenotrophomonas spp., certain species of the family Enterobacteriaceae, Bacteroides spp., Peptostreptococcus spp., and Propionibacterium spp. Comparison of the MICs and minimum bactericidal concentrations (MBCs) of pexiganan for 143 isolates representing 32 species demonstrated that for 92% of the isolates tested, MBCs were the same or within 1 twofold difference of the MICs, consistent with a bactericidal mechanism of action. Killing curve analysis showed that pexiganan killed Pseudomonas aeruginosa rapidly, with 10(6) organisms/ml eliminated within 20 min of treatment with 16 micrograms of pexiganan per ml. No evidence of cross-resistance to a number of other antibiotic classes was observed, as determined by the equivalence of the MIC50s and the MIC90s of pexiganan for strains resistant to oxacillin, cefazolin, cefoxitin, imipenem, ofloxacin, ciprofloxacin, gentamicin, and clindamicin versus those for strains susceptible to these antimicrobial agents. Attempts to generate resistance in several bacterial species through repeated passage with subinhibitory concentrations of pexiganan were unsuccessful. In conclusion, pexiganan exhibits properties in vitro which make it an attractive candidate for development as a topical antimicrobial agent.     

Type II Topoisomerase Quinolone Resistance-Determining Regions of Aeromonas caviae, A. hydrophila, and A. sobria Complexes and Mutations Associated with Quinolone Resistance

Most Aeromonas strains isolated from two European rivers were previously found to be resistant to nalidixic acid. In order to elucidate the mechanism of this resistance, 20 strains of Aeromonas caviae (n = 10), A. hydrophila (n = 5), and A. sobria (n = 5) complexes, including 3 reference strains and 17 environmental isolates, were investigated. Fragments of the gyrA, gyrB, parC, and parE genes encompassing the quinolone resistance-determining regions (QRDRs) were amplified by PCR and sequenced. Results obtained for the six sensitive strains showed that the GyrA, GyrB, ParC, and ParE QRDR fragments of Aeromonas spp. were highly conserved (> or =96.1% identity), despite some genetic polymorphism; they were most closely related to those of Vibrio spp., Pseudomonas spp., and members of the family Enterobacteriaceae (72.4 to 97.1% homology). All 14 environmental resistant strains carried a point mutation in the GyrA QRDR at codon 83, leading to the substitution Ser-83-->Ile (10 strains) or Ser-83-->Arg. In addition, seven strains harbored a mutation in the ParC QRDR either at position 80 (five strains), generating a Ser-80-->Ile (three strains) or Ser-80-->Arg change, or at position 84, yielding a Glu-84-->Lys modification. No amino acid alterations were discovered in the GyrB and ParE QRDRs. Double gyrA-parC missense mutations were associated with higher levels of quinolone resistance compared with the levels associated with single gyrA mutations. The most resistant strains probably had an additional mechanism(s) of resistance, such as decreased accumulation of the drugs. Our data suggest that, in mesophilic Aeromonas spp., as in other gram-negative bacteria, gyrase and topoisomerase IV are the primary and secondary targets for quinolones, respectively.     

Identification of pink-pigmented bacteria isolated from environmental water samples and their biofilm formation abilities

Sixty-seven strains of pink-pigmented bacteria, which were isolated from environmental water samples collected nationwide, were identified by partial 16S rDNA sequence analysis. In addition, the biofilm formation ability of the isolates was experimentally investigated. We could identify only 2 strains at the species level: Pedobacter roseus HS-38 and Runella slithyformis HS-77. The results showed that of the strains tested, 22 strains (32.8%) were Pedobacter spp., which was most frequently identified, followed by 19 strains (28.4%) of Arcicella spp., 16 strains (23.9%) of Deinococcus spp., 5 strains (7.5%) of Roseomonas spp., 4 strains (6.0%) of Flectobacillus spp. and 1 strain (1.5%) of Runella sp. Most isolates showed low similarity values to previously known species, and they were found to be novel species. At a result, it was difficult to identify environmental water-derived pink-pigmented bacteria at the species level. On the other hand, when we measured the absorbance by the crystal violet staining to examine the quantities of biofilm formation of these strains, fifty-five (82.0%) of the 67 isolates formed biofilm. The absorbance of Deinococcus sp. HS-75 was the highest (3.56). When comparing the absorbance values among the genera, Roseomonas spp. showed the highest absorbance (mean:1.62), followed by Deinococcus spp. (mean: 1.03), and Arcicella spp. (mean: 1.01). Strains of Flectobacillus spp. (mean: 0.48) and Pedobacter spp. (mean: 0.42) showed lower absorbance values. As above, it was shown that, at the species level, the pink-pigmented bacteria in the water in the Japanese environment had various levels of ability to form biofilm.     

Antibacterial activity of BMS-180680, a new catechol-containing monobactam.

The in vitro activities of a new catechol-containing monobactam, BMS-180680 (SQ 84,100), were compared to those of aztreonam, ceftazidime, imipenem, piperacillin-tazobactam, ciprofloxacin, amikacin, and trimethoprim-sulfamethoxazole. BMS-180680 was often the most active compound against many species of the family Enterobacteriaceae, with MICs at which 90% of the isolates were inhibited (MIC90s) of < or = 0.5 microg/ml for Escherichia coli, Klebsiella spp., Citrobacter diversus, Enterobacter aerogenes, Serratia marcescens, Proteus spp., and Providencia spp. BMS-180680 had moderate activities (MIC90s of 2 to 8 microg/ml) against Citrobacter freundii, Morganella morganii, Shigella spp., and non-E. aerogenes Enterobacter spp. BMS-180680 was the only antibiotic evaluated that was active against >90% of the Pseudomonas aeruginosa (MIC90, 0.25 microg/ml), Burkholderia cepacia, and Stenotrophomonas maltophilia (MIC90s, 1 microg/ml) strains tested. BMS-180680 was inactive against most strains of Pseudomonas fluorescens, Pseudomonas stutzeri, Pseudomonas diminuta, and Burkholderia pickettii. BMS-180680 was moderately active (MIC90s of 4 to 8 microg/ml) against Alcaligenes spp. and Acinetobacter lwoffii and less active (MIC90, 16 microg/ml) against Acinetobacter calcoaceticus-Acinetobacter baumanii complex. BMS-180680 lacked activity against gram-positive bacteria and anaerobic bacteria. Both tonB and cir fiu double mutants of E. coli had greatly decreased susceptibility to BMS-180680. Of the TEM, PSE, and chromosomal-encoded beta-lactamases tested, only the K1 enzyme hydrolyzed BMS-180680 to any measurable extent. Like aztreonam, BMS-180680 bound preferentially to penicillin-binding protein 3. The MICs of BMS-180680 were not influenced by the presence of hematin or 5% sheep blood in the test medium or with incubation in an atmosphere containing 5% CO2. BMS-180680 MICs obtained under strict anaerobic conditions were significantly higher than those obtained in ambient air.     

In vitro activity of CI-919 (AT-2266), an oral antipseudomonal compound.

We tested CI-919 (AT-2266), a nalidixic acid analog, against 555 gram-positive and gram-negative bacteria, using microbroth or agar dilution methods. The activity of CI-919 was compared with those of cephalosporins, tobramycin, ticarcillin, dicloxacillin, rifampin, chloramphenicol, ampicillin, and trimethoprimsulfamethoxazole. The minimal inhibitory concentrations of CI-919 for 90% of isolates were (in micrograms per milliliter): Pseudomonas spp. (including Pseudomonas aeruginosa), 4.0; Enterobacteriaceae, 0.5; Staphylococcus spp., 2.0; Haemophilus influenzae, 0.12; Campylobacter jejuni, 0.12; and enterococci, 16. The minimal inhibitory concentrations of CI-919 for 90% of 82 tobramycin-resistant, gram-negative strains was 4.0 micrograms/ml. CI-919 was bactericidal for most isolates, showing no cross-resistance with unrelated antimicrobial agents, and was stable for 11 weeks at temperatures ranging from 22 to -70 degrees C. Inoculum size and media pH had little effect on the antibacterial activity of CI-919 for nine strains tested. CI-919 may be useful as an oral antibiotic for the treatment of infections due to diverse bacteria, including P. aeruginosa.     

Antibacterial activity of norfloxacin.

Norfloxacin, a new quinoline derivative, was studied in vitro, and determinations of agar dilution minimal inhibitory concentrations (MICs) and broth dilution MICs and MBCs were made. Nalidixic acid and cinoxacin were used as comparative agents. Norfloxacin was found to be extremely active against all strains tested of Escherichia coli, Klebsiella spp., Proteus mirabilis, indole-positive Proteus spp. Serratia spp., Citrobacter spp., and Enterobacter spp., with MICs normally below 1 microgram/ml. It also was found to be highly active against Pseudomonas aeruginosa, Staphylococcus saprophyticus, and enterococci, which are all resistant to nalidixic acid and cinoxacin. The MICs for norfloxacin obtained by broth dilution were slightly higher than those obtained by agar dilution, whereas the reverse was true for nalidixic acid and cinoxacin. The MBCs of norfloxacin were only slightly higher than the MICs, even at high inocula. The in vitro activity of norfloxacin was not dependent on the inoculum size, whereas both the MICs and the MBCs of nalidixic acid increased markedly for many of the strains tested when the inoculum was increased in broth dilution from 10(3) to 10(6) colony-forming units per ml. Norfloxacin seems to be a promising antibacterial agent for the treatment of urinary tract infections, especially those caused by Pseudomonas spp. and other species today requiring the use of injectable antibiotics.     

巴尔通体MALDI-TOF MS数据库的建立与鉴定方法的评价

目的 建立巴尔通体的基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)数据库和质谱鉴定方法,利用野生菌株进行验证、评价.方法 应用MALDI-TOF MS采集巴尔通体ATCC标准菌株和国内流行菌株的质谱数据,每株菌采集24张的质谱图集,获得特定的蛋白指纹图谱,汇总成不同种巴尔通体的标准质谱图,建立巴尔通体MA...