Current Issue : July - September Volume : 2017 Issue Number : 3 Articles : 7 Articles
Recent studies have demonstrated that drug antimicrobial activity is enhanced when metallic nanoparticles are used as an\ninorganic support, obtaining synergic effects against microorganisms. The cationic antimicrobial peptide ubiquicidin 29ââ?¬â??41\n(UBI) has demonstrated high affinity and sensitivity towards fungal and bacterial infections. The aim of this research was\nto prepare and evaluate the antimicrobial efficacy of engineered multivalent nanoparticle systems based on silver or gold\nnanoparticles functionalized with UBI. Spectroscopy techniques demonstrated that NPs were functionalized with UBI mainly\nthrough interactions with the -NH2 groups. A significant increase in the antibacterial activity against Escherichia coli and\nPseudomonas aeruginosa was obtained with the conjugate AgNP-UBI with regard to that of AgNP.No inhibition of bacterial growth\nwas observed withAuNP andAuNP-UBI using a nanoparticle concentration of up to 182 ...
The objective of this research was to screen, select and isolate actinomycetes from 10 salty soil samples. The ability of the isolated strains to produce antimicrobials metabolites was evaluated against pathogenic strains: Escherichia coli; Staphylococcus aerus and Candida albicans by using disc diffusion agar plate technique. Optimization of the production of bioactive metabolites from the most potent isolate was also demonstrated. The crude extract of the metabolites produced by the 41 actinomycetes isolates proved to have antimicrobial activity against one or all the tested pathogen. Among all the isolated strains, NRC-S4 isolate exhibited highest activity against all the tested pathogen and was selected for further studies. Out of 13 tested carbon sources, starch was the most suitable one. From 11 organic and inorganic tested nitrogen sources, ammonium nitrate was found to be the best source. The maximum antimicrobial bioactive metabolites produced by the optimized culture medium containing g/L sea water: soluble starch, 35; NH4NO3, 3.5; K2HPO4, 1; MgSO4.7H2O, 0.5; CaCO3, 3; with inoculums volume of 5% at pH7, 30°C and 170 rpm for 12 days....
Procedure ofmanufacturing K. pinnata water extracts containing cecropin P1 (CecP1) fromthe formerly described transgenic plants\nis established. It included incubation of leaves at +4âË?Ë?C for 7 days, mechanical homogenization of leaves using water as extraction\nsolvent, and heating at +70âË?Ë?C for inactivating plant enzymes. Yield of CecP1 (after heating and sterilizing filtration) was 0.3% of total\nprotein in the extract. The water extract of K. pinnata + CecP1 exhibits favorable effect on healing of wounds infected with S. aureus\n(equal to Cefazolin) and with a combination of S. aureus with P. aeruginosa (better than Cefazolin). Wild-type K. pinnata extract\nexhibited evident microbicide activity against S. aureus with P. aeruginosa but itwas substantially strengthened in K. pinnata +CecP1\nextract. K. pinnata extracts (both wild-type and transgenic) did not exhibit general toxicity and accelerated wound recovery. Due to\nimmunomodulating activity, wild-type K. pinnata extract accelerated granulation of the wound bed and marginal epithelialization\neven better than K. pinnata + CecP1 extract. Immunomodulating and microbicide activity of K. pinnata synergizes with microbicide\nactivity of CecP1 accelerating elimination of bacteria....
Amylase is an important and indispensable enzyme that plays a pivotal role in the field of biotechnology. It is produced mainly\nfrom microbial sources and is used in many industries. Industrial sectors with top-down and bottom-up approaches are currently\nfocusing on improving microbial amylase production levels by implementing bio engineering technologies. The further support\nof energy consumption studies, such as those on thermodynamics, pinch technology, and environment-friendly technologies, has\nhastened the large-scale production of the enzyme. Herein, the importance of microbial (bacteria and fungi) amylase is discussed\nalong with its production methods from the laboratory to industrial scales....
The present study was conducted to evaluate the performance of cefoxitin disc diffusion method and oxacillin broth microdilution\nmethod for detection of methicillin resistant S. aureus (MRSA), taking presence of mecA gene as reference. In addition, inducible\nclindamycin resistance and beta-lactamase production were studied and minimum inhibitory concentration (MIC) of vancomycin\nfor S. aureus isolates was determined. A total of 711 nonrepeated pus/wound swab samples from different anatomic locations were\nincluded in the study.The Staphylococcus aureus was identified on the basis of colony morphology, Gram�s stain, and biochemical\ntests. A total of 110 (15.47%) S. aureus isolates were recovered, of which 39 (35.50%) isolates were identified as MRSA by cefoxitin\ndisc diffusion method. By oxacillin broth microdilution method, 31.82% of the Staphylococcus aureus isolates were found to be\nMRSA. However, mecA gene was present in only 29.1% of the isolates. Further, beta-lactamase production was observed in 71.82%\nof the isolates, while inducible clindamycin resistance was found in 10% of S. aureus isolates. The MIC value of vancomycin for S.\naureus ranged from 0.016 ...
Background. The current definitive treatment of Buruli ulcer with antibiotics makes the issue of antimicrobial drug resistance\nan unavoidable one. This is as a result of drug misuse by health personnel and patients� noncompliance to treatment regimen.\nMonitoring of these factors and screening for new effective antimicrobials are crucial to effective management of Buruli ulcer\ndisease. This study therefore investigated the inhibitory activity of some antibiotics against isolates of Mycobacterium ulcerans.\nMethods. Activity of eight antibiotics was tested against twelve M. ulcerans isolates (2 reference strains and 10 clinical isolates).\nThe anti-M. ulcerans activities were determined by the agar dilution method and the minimum inhibitory concentrations (MICs)\nwere determined by the agar proportion method. Results. All antimicrobials investigated had activity against M. ulcerans isolates\ntested. The MICs ranged from 0.16 ...
Background. Early detection of Gram-positive bacteremia and timely appropriate antimicrobial therapy are required for decreasing\npatient mortality. The purpose of our study was to evaluate the performance of the Verigene Gram-positive blood culture assay\n(BC-GP) in two special healthcare settings and determine the potential impact of rapid blood culture testing for Gram-positive\nbacteremia within the Japanese healthcare delivery system. Furthermore, the study included simulated blood cultures, which\nincluded a library of well-characterized methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci\n(VRE) isolates reflecting different geographical regions in Japan. Methods. A total 347 BC-GP assays were performed on clinical and\nsimulated blood cultures. BC-GP results were compared to results obtained by reference methods for genus/species identification\nand detection of resistance genes using molecular and MALDI-TOF MS methodologies. Results. For identification and detection\nof resistance genes at two clinical sites and simulated blood cultures, overall concordance of BC-GP with reference methods was\n327/347 (94%). The time for identification and antimicrobial resistance detection by BC-GP was significantly shorter compared to\nroutine testing especially at the cardiology hospital, which does not offer clinical microbiology services on weekends and holidays.\nConclusion. BC-GP generated accurate identification and detection of resistance markers compared with routine laboratory\nmethods for Gram-positive organisms in specialized clinical settings providing more rapid results than current routine testing....
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