Anti-microbial active composite nanoparticles with magnetic core and photocatalytic shell: TiO2-NiFe2O4 biomaterial system

Reverse micelle and chemical hydrolysis techniques have been successfully combined to synthesize composite nanoparticles consisting of a photocatalytic shell of titania and a magnetic core of nickel ferrite. The nature of titania shell, i.e. anatase or brookite, depends on the TiO₂ and NiFe₂O₄ molar ratio. The work presented here describes the photocatalytic and anti-microbial activity of the composite nanoparticles together with the magnetic characteristics of the nickel ferrite core. The TiO₂-coated NiFe₂O₄ nanoparticles retain the magnetic characteristics of uncoated nanocrystalline nickel ferrites (superparamagnetism; absence of hysteresis, remanence and coercivity at 300 K) encouraging their application as removable anti-microbial photocatalyst nanoparticles that can be extracted from the sprayed surface (human body or environment) after exposure.     

Molecular characterization of a novel pattern recognition protein from nonspecific cytotoxic cells: sequence analysis, phylogenetic comparisons and anti-microbial activity of a recombinant homologue

Nonspecific cytotoxic cells (NCC) are the first identified and most extensively studied killer cell population in teleosts. NCC kill a wide variety of target cells including tumor cells, virally transformed cells and protozoan parasites. The present study identified a novel evolutionarily conserved oligodeoxynucleotide (ODN) binding membrane protein expressed by channel catfish (Ictalurus punctatus) NCC. Peptide fingerprinting analysis of the ODN binding protein (referred to as NCC cationic anti-microbial protein-1/ncamp-1) identified a peptide that was used to design degenerate primers. A catfish NCC cDNA library was used as template with these primers and the PCR-amplified product was sequenced. The translated sequence contained 203 amino acids (molecular mass of 22,064.63 Da) with characteristic lysine rich regions and a pI=pH 10.75. Sequence comparisons of this protein indicated similarity to zebrafish (51.2%) histone family member 1-X and (to a lesser extent) to trout H1. A search of EST databases confirmed that ncamp-1 is also expressed in various tissues of channel catfish as well as zebrafish. Inspection for signature repeats in ncamp-1 and comparisons with histone-like peptides from different species indicated the presence of multiple lysine based motifs composed of AKKA or PKK repeats. The novel protein was cloned, expressed in E. coli and the recombinant was used to generate rabbit anti-serum. The recombinant ncamp-1 bound GpC and CpG ODNs and was detected with homologous anti-ncamp-1 polyclonal antibodies. Western blots of NCC membranes using anti-ncamp-1 serum detected a 29 kDa protein. Binding competition experiments demonstrated that anti-ncamp-1 antibodies and GpC bound to the same protein on NCC. Two different truncated forms of ncamp-1 as well as the full-length recombinant protein exhibited anti-microbial activity. The present study demonstrated the expression by NCC of a new membrane protein that may participate in the recognition of bacterial DNA and as such participate in innate anti-microbial immune responses in teleosts.     

支原体耐药性与抗菌药消耗量相关性研究

目的：了解支原体耐药性与抗生素消耗量之间的相关性。方法：对112份解脲支原体阳性标本进行9种抗菌药敏感性试验，统计2002～2003年有关药物的消耗量，分析解脲支原体耐药率与相应药品消耗量之间的关系。结果：多因素逐步回归分析表明上年度相关药物成人剂型的消耗量是有显著性意义的相关因素（r=0．858，F=16.778，P〈0．01）。结论：支原体的耐药率主要与上一年度的相关药物消耗量相关。     

肺清颗粒药效学作用初探

目的研究肺清颗粒镇咳、祛痰、平喘和抗菌作用。方法以小鼠氨水引咳法、小鼠枸橼酸引咳法和豚鼠枸橼酸引咳法观察其镇咳作用;以小鼠酚红排泌法观察其祛痰作用;以豚鼠乙酰胆碱-组胺引喘法和豚鼠离体气管条试验观察其平喘作用;采用抑菌圈测定法观察肺清颗粒的体外抑菌作用。结果肺清颗粒对小鼠氨水引咳具有显著的镇咳作用,对乙酰胆碱-组胺所致的豚鼠哮喘具有显著的平喘作用;对组胺或乙酰胆碱致痉的豚鼠离体气管条有显著的解痉作用;体外对金黄色葡萄球菌、肺炎球菌和肺炎克雷伯菌有一定的抑制作用。结论肺清颗粒对实验动物具有显著的镇咳、祛痰及平喘作用,并具有一定的抗菌作用。     

浙江省2003～2004年甲副伤寒菌株质粒图谱分析

目的：探讨浙江省2003、2004年不同地区分离的甲型副伤寒菌株质粒基因定位及与致病性的关系。方法：利用快速小量质粒提取技术及电泳图谱方法，对浙江省2003、2004年暴发点病人和住院病人分离的部分甲型副伤寒菌株进行质粒图谱分析并做药敏试验。结果：分析发现选择的78株菌株中，78株(100％)对红霉素(ETM)耐药，77株(98．72％)对利福平(RFP)、链霉素(SM)及头孢拉定(CV)耐药，76株(97．44％)对羧苄青霉素(CAR)及磺胺(SD)耐药，64株(82．05％)对强力霉素(DC)耐药；大多数菌株带有一20kb大小质粒，所有菌株均带有2．2kh大小的质粒。结论：甲型副伤寒菌对ETM、RFP、CAR、CV、SM、SD、DC耐药，并认为具有多重耐药性是浙江省甲型副伤寒发病率持续高发的主要原因。     

藏药短穗兔耳草有效部位的抑菌活性研究

目的对短穗兔耳草Lagotis brachystachyM axim挥发油及全草分萃取段进行了抑菌活性研究。方法选择金黄色葡萄球菌、枯草芽孢杆菌、伤寒沙门氏菌、大肠埃希菌和铜绿假单胞菌为代表菌种,筛选出了对所选细菌的生长具有明显抑制作用的抗菌活性部分。结果短穗兔耳草挥发油、石油醚萃取部分、醋酸乙酯萃取部分、正丁醇萃取部分都具有部分活性。结论短穗兔耳草挥发油对金黄色葡萄球菌和枯草芽孢杆菌有抑菌活性,石油醚萃取部分对5种细菌都不敏感,醋酸乙酯萃取部分对金黄色葡萄球菌、枯草芽孢杆菌和大肠埃希菌有抑菌活性,正丁醇萃取部分对金黄色葡萄球菌、枯草芽孢杆菌、伤寒沙门氏菌和铜绿假单胞菌有抑菌活性。     

量化感染与抗菌策略对慢性阻塞性肺病急性发作患者预后的影响

目的　试图找出针对慢性阻塞性肺病 (COPD)急性发作患者合适的抗菌治疗策略。方法　根据SepsisScore(SS)评分 ,对 4 7例接受过NIPPV治疗的COPD急性发作患者进行肺部感染严重度的评分 ,并依据治疗效果和支气管—肺泡灌洗液细菌学检测结果评价抗菌治疗是否充分 ,以及对临床转归的影响。结果　监测COPD急性发作期患者的SS ,发现当SS≤10时 ,充分的经验性抗菌治疗可明显降低死亡率 ;但是 ,当SS积分 >10时 ,抗菌治疗策略并不能明显改善患者的预后。结论　根据COPD急性发作患者感染严重度 ,早期采取相应抗菌治疗策略 ,可降低死亡率并防止滥用抗菌药物     

Screening for anti-infective properties of several medicinal plants of the Mauritians flora

Several plants of the Mauritian flora alleged to possess anti-infective properties were studied against different strains of pathogenic bacteria and fungi. The grounded dried plant materials were extracted with different extractants and screened for anti-microbial activity using the disk diffusion and the micro-dilution techniques. Preliminary screening revealed that the methanol extracts were most active. Salmonella enteritidis, Enterobacter cloacae and Bacillus subtilis were the three test organisms, which were found to be susceptible to all the crude methanolic extracts of the different plants investigated (100% susceptibility), followed by Escherichia coli (57.1%) and Pseudomonas aeruginosa (57.1%), and Staphylococcus aureus (28.6%). The lowest minimum inhibitory concentration recorded for the different crude methanol extracts against Staphylococcus aureus, Escherichia coli, Salmonella enteritidis, Enterobacter cloacae, Bacillus subtilis and the mould fungus Candida albicans were 500, 1000, 125, 250, 1000 and 125 micro g/ml, respectively. Bioautography using Cladosporium cucumerinum revealed that dichloromethane (DCM) extracts had the highest activity against the phytopathogenic fungus. It was also noted that the DCM extracts of Michelia champaca and Antidesma madagascariense yielded the maximum number of growth inhibiting compounds against Cladosporium cucumerinum. Activity of the different crude extracts was also investigated against several phytopathogenic filamentous fungi, Colletotrichum glocosporoides, Rhizoctonia solani, Sclerotinia sclerotium, Guignardia sp. and Fusarium oxysporum. It was found that crude hexane extracts as well as crude DCM extracts exhibited marked activity against several strains of fungi, especially Colletotrichum glocosporoides, Sclerotinia sclerotium and Guignardia sp.     

Synthesis, characterization and in vitro biological activity studies of Cu-M (M = Cu2+, Co2+, Ni2+, Mn2+, Zn2+) bimetallic complexes

Six new bimetallic complexes of the type CuCu, CuCo, CuNi, CuZn and CuMn were prepared. The structures of these complexes and the ligand have been proposed on the basis of FAB mass, elemental analysis, UV-vis, IR, EPR and CV studies. All the complexes completely cleave pBS (SK-) DNA at a concentration of 10 microM; however, even at lower concentrations of 2 microM and 0.1 microM, the complexes (I and Ia) showed partial cleavage. The results of the fluorescence binding studies of the metal complexes with CT-DNA showed that the presence of aliphatic ligands added additional binding effects including electrostatic, hydrogen binding and vander Waals interactions. Complexes (I, Ia) showed 50% inhibition of COX-1 and COX-2 activities at as low a concentration as 12.5 microM, 13.5 microM, 14 microM and 14.5 microM. Inhibition assay of top I and top II by different complexes in mutant yeast strains (JN394, JN394 t(-1) and JN394 t(2-5)) with all the complexes showed significant inhibition of topoisomerase at 5 microM concentration. Complexes I and Ia exhibited good anti-microbial activities against all human pathogens tested except Klebsiella pneumoniae. The following studies showed that among the synthesized bimetallic complexes, complexes I and Ia seem to be promising candidates possessing DNA cleavage activities besides anti-microbial and anti-inflammatory properties to serve as chemical nucleases and chemotherapeutic agents.