scholarly journals Synthesis of cyclotetrapeptide analogues of c-PLAI and evaluation of their antimicrobial properties

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Rani Maharani ◽  
Orin Inggriani Napitupulu ◽  
Jelang M. Dirgantara ◽  
Ace Tatang Hidayat ◽  
Dadan Sumiarsa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Properties ◽  
Trichophyton Mentagrophytes ◽  
Solution Phase ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Aromatic Residues ◽  
Gram Positive Bacteria ◽  
Lysine Residues ◽  
Bacteria And Fungi

Antimicrobial peptides (AMPs) are interesting compounds owing to their ability to kill several pathogens. In order to identify new AMPs, c-PLAI analogues were synthesized and evaluated together with their linear precursors for their antimicrobial properties against two Gram-positive bacteria ( Staphylococcus aureus and Bacillus cereus ), two Gram-negative bacteria ( Escherichia coli and Klebsiella pneumoniae ), and two fungal strains ( Candida albicans and Trichophyton mentagrophytes ). The new c-PLAI analogues were prepared through a combination of solid- and solution-phase syntheses, as previously employed for the synthesis of c-PLAI. The antimicrobial activity tests showed that the synthetic parent peptide c-PLAI was inactive or weakly active towards the bioindicators employed in the assay. The tests also indicated that cyclic c-PLAI analogues possessed enhanced antimicrobial properties against most of the bacteria and fungi tested. Furthermore, this study revealed that analogues containing cationic lysine residues displayed the highest activity towards most bioindicators. A combination of lysine and aromatic residues yielded analogues with broad-spectrum antimicrobial properties.

scholarly journals Pyelonephritis in Pediatric Uropathic Patients: Differences from Community-Acquired Ones and Therapeutic Protocol Considerations. A 10-Year Single-Center Retrospective Study

Children ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 436
Author(s):  
Giovanni Parente ◽  
Tommaso Gargano ◽  
Stefania Pavia ◽  
Chiara Cordola ◽  
Marzia Vastano ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Retrospective Study ◽  
Success Rate ◽  
Pediatric Population ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Significant Difference ◽  
Klebsiella Spp

Pyelonephritis (PN) represents an important cause of morbidity in the pediatric population, especially in uropathic patients. The aim of the study is to demonstrate differences between PNs of uropathic patients and PNs acquired in community in terms of uropathogens involved and antibiotic sensitivity; moreover, to identify a proper empiric therapeutic strategy. A retrospective study was conducted on antibiograms on urine cultures from PNs in vesicoureteral reflux (VUR) patients admitted to pediatric surgery department and from PNs in not VUR patients admitted to Pediatric Emergency Unit between 2010 and 2020. We recorded 58 PNs in 33 patients affected by VUR and 112 PNs in the not VUR group. The mean age of not VUR patients at the PN episode was 1.3 ± 2.6 years (range: 20 days of life–3 years), and almost all the urine cultures, 111 (99.1%), isolated Gram-negative bacteria and rarely, 1 (0.9%), Gram-positive bacteria. The Gram-negative uropathogens isolated were Escherichia coli (97%), Proteus mirabilis (2%), and Klebsiella spp. (1%). The only Gram-positive bacteria isolated was an Enterococcus faecalis. As regards the antibiograms, 96% of not VUR PNs responded to beta-lactams, 99% to aminoglycosides, and 80% to sulfonamides. For the VUR group, mean age was 3.0 years ± 3.0 years (range: 9 days of life–11 years) and mean number of episodes per patient was 2.0 ± 1.0 (range: 1–5); 83% of PNs were by Gram-negatives bacteria vs. 17% by Gram-positive: the most important Gram-negative bacteria were Pseudomonas aeruginosa (44%), Escherichia coli (27%), and Klebsiella spp. (12%), while Enterococcus spp. determined 90% of Gram-positive UTIs. Regimen ampicillin/ceftazidime (success rate: 72.0%) was compared to ampicillin/amikacin (success rate of 83.0%): no statistically significant difference was found (p = 0.09). The pathogens of PNs in uropathic patients are different from those of community-acquired PNs, and clinicians should be aware of their peculiar antibiotic susceptibility. An empiric therapy based on the association ampicillin + ceftazidime is therefore suggested.

Survival of some non-starter bacteria in naturally ripened and enzyme-accelerated Cheddar cheese

1988 ◽  
Vol 55 (4) ◽  
pp. 597-602 ◽  
Author(s):  
Lydia Bautista ◽  
Rohan G. Kroll
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Enterococcus Faecalis ◽  
Enzyme System ◽  
Cheddar Cheese ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Ripening Period ◽  
Gram Positive Bacteria

SummaryEffects of the addition of a proteinase (Neutrase 1–5S) and a peptidase (aminopeptidase DP-102) as agents for accelerating the ripening of Cheddar cheese on the survival of some non-starter bacteria (Staphylococcus aureus, Enterococcus faecalis, Escherichia coliand aSalmonellasp.) were studied throughout a 4-month ripening period. The enzymes were found to have no significant effect on the survival of the Gram-positive bacteria but some significant effects were observed, at some stages of the ripening period, with the Gram-negative bacteria in that lower levels were recovered from cheeses treated with the enzyme system.

scholarly journals Different Modes of Action of Naphthyridones in Gram-Positive and Gram-Negative Bacteria

2006 ◽  
Vol 50 (1) ◽  
pp. 385-387 ◽  
Author(s):  
Ed T. Buurman ◽  
Kenneth D. Johnson ◽  
Roxanne K. Kelly ◽  
Kathy MacCormack
Keyword(s):  
Escherichia Coli ◽  
Haemophilus Influenzae ◽  
Mode Of Action ◽  
Bacterial Pathogens ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Modes Of Action

ABSTRACT Naphthyridones that were recently described as a class of translation inhibitors in gram-positive bacteria mediate their mode of action via GyrA in Haemophilus influenzae and Escherichia coli. These are the first examples of compounds in which modes of action in different bacterial pathogens are mediated through widely different targets.

scholarly journals Synthesis, Antibacterial and Antifungal Properties of Cyclohexane Tosyloxyimine Derivative

2019 ◽  
Vol 4 (3) ◽  
pp. 1-4
Author(s):  
Shoaib M
Keyword(s):  
Antimicrobial Agents ◽  
Sulfonyl Chloride ◽  
Antimicrobial Properties ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Bacteria And Fungi ◽  
Agar Well Diffusion Assay ◽  
Antibacterial And Antifungal ◽  
Candida Pseudotropicalis

Due to increasing antimicrobial resistance, functionally substituted cyclohexane derivatives are being explored as potential antimicrobial agents. Reaction of diethyl 4 - hydroxy - 6 - (hyd - roxyimino) - 4 - methyl - 2 - phenylcyclohexane - 1,3 - dicarboxylate with 4 - toluene sulfonyl chloride in boiling acetone in the presence of equimolar triethylamine resulted in formation of diethyl - 4 - hydroxy - 4 - methyl - 2 - phenyl - 6 - ((tosyloxy)imino) cyclohexane - 1,3 - dicarboxylate. The structure of novel compound was characterized by 1 H and 13 C NMR spectra and elemental analysis was performed. Agar well diffusion assay was used to screen novel compound against Gram - positive bacteria, Gram - negative bacteria and fungi. Test compound showed better antimicrobial properties against Gram - negative bac teria as compared to Gram - positive bacteria and fungi. Acinetobacter baumannii BDU - 32 was found to be most sensitive bacteria while Candida pseudotropicalis BDU MA88 was found to be most sensitive yeast.

scholarly journals Synthesis, Characterization and Antimicrobial Activities of Co (III) and Fe (III) Complexes of Imino-N-heterocyclic Carbenes Ligands

2021 ◽  
pp. 59-67
Author(s):  
Samaila Abubakar ◽  
Musa Muktari ◽  
Rejoice Atiko
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhi ◽  
Antimicrobial Activities ◽  
Heterocyclic Carbenes ◽  
Gram Negative Bacteria ◽  
Disc Diffusion ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria

The synthesis and antimicrobial application of Co (III) and Fe (III) complexes of imine functionalized N-heterocyclic carbene (Imino-NHC) ligands is reported. The ligand precursors 1-(2-[(hydroxyl-benzylidene)-amino]-ethyl)-3-R-3H-imidazol-1-ium bromide where R = pyridyl (1a) and benzyl (1b) have been reported in our previous work. The in-situ generated ligands of 1a and 1b have been successfully coordinated to CoBr2 and [FeI(Cp)(CO)2] leading to the isolation of air-stable N^C^N^O four coordinate Co(III)  complex 2 and a six-coordinate Fe(III) complex 3. The synthesised complexes were both found to be NMR inactive hence were characterize using FTIR and LRMS. The complexes were screened for antimicrobial activities against four gram-negative bacteria Escherichia Coli (E-coli), Shigella, Klebsiella pneumoniae (K. Pneumoniae) and Salmonella typhi (S. typhi) and a gram positive bacteria Staphylocossus aureus (S. aureus). The antimicrobial test was conducted using disc diffusion methods and based on the concentrations of 100, 200, 300, 400 and 500 µg/ mL, significant activities were recorded for both cobalt and the iron complexes.

The role of biosynthesized silver nanoparticles in antimicrobial mechanisms

2021 ◽  
Vol 22 ◽  
Author(s):  
Bianca PizzornoBackx ◽  
Mayara Santana dos Santos ◽  
Otávio Augusto Leitão dos Santos ◽  
Sérgio Antunes Filho
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Antimicrobial Properties ◽  
New Drugs ◽  
Gram Negative Bacteria ◽  
New Materials ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Emergence Of Resistance

: Nanotechnology is an area of science able to develop new materials. The relation between nanotechnology and microbiology is essential for the development of new drugs and vaccines. The main advantage of blend in both areas is to associate the latest technology to obtain new ways to solve problems related to microorganisms. This review seeks to investigate nanoparticle formation's antimicrobial properties, primarily when connected to the green synthesis of silver nanoparticles. The development of new sustainable methods for nanoparticle production has been instrumental in designing alternative, non-toxic, energy-friendly, and environmentally friendly routes. In this sense, it is necessary to study silver nanoparticles' green synthesis concerning their antimicrobial properties. Antimicrobial mechanisms of silver nanoparticles demonstrate efficiency to gram-positive bacteria, gram-negative bacteria, fungi, viruses, and parasites. However, attention is needed with the emergence of resistance to these antimicrobials. This article seeks to relate the parameters of green silver-based nanosystems with the efficiency of antimicrobial activity.

scholarly journals Paper modified with ZnO nanorods – antimicrobial studies

2012 ◽  
Vol 3 ◽  
pp. 684-691 ◽  
Author(s):  
Mayuree Jaisai ◽  
Sunandan Baruah ◽  
Joydeep Dutta
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Aspergillus Niger ◽  
Zno Nanorods ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Tissue Paper ◽  
Gram Positive Bacteria ◽  
Lighting Conditions

Paper with antimicrobial properties was developed through in situ growth of ZnO nanorods. The targeted application for this type of paper is in health centers as wallpaper, writing paper, facemasks, tissue paper, etc. The paper was tested on three model microbes, Gram-positive bacteriaStaphylococcus aureus,Gram-negative bacteriaEscherichia coliand common airborne fungusAspergillus niger. No viable bacterial colonies or fungal spores could be detected in the areas surrounding test samples of the antimicrobial paper. Gram-negative bacteriaEscherichia coliwere found to be inhibited in an area that is 239% and 163% the area of the paper sample under different room lighting conditions, i.e., halogen and fluorescent lamp illumination, respectively. For Gram-positive bacteriaStaphylococcus aureusthe zones of inhibition surrounding the paper samples are 102% and 70%, and forAspergillus niger, 224% and 183% of the sample area, under similar lighting conditions.

Composition and Antimicrobial Activity of the Essential Oil of a Wild Kiwi

2011 ◽  
Vol 322 ◽  
pp. 160-163
Author(s):  
Yin Lu ◽  
Hong Chen
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Fungal Species ◽  
Gram Negative Bacteria ◽  
Significant Activity ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Leaf Oil ◽  
First Time

A medicinal wild kiwi in China, Actinidia valvata Dunn, has been well known for its activities against leprosy and cancers. The compositions and the antimicrobial activity of its leaf oil were reported for the first time. The oil obtained by hydrodistillation and analyzed by GC and GC-MS, was characterized by the high content of monoterpenes. Linalool (48.14%) is the major component identified, followed by 1,2-dimethyl-lindoline (7.94%), linolenic acid methylester (6.57%) and (E)-phytol (5.29%). The antimicrobial activity of the oil was evaluated against four bacterial and three fungal species. The results showed that it exhibited a mild antibacterial activity against two Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), a significant activity against Gram-negative bacteria (Escherichia coli), and no activity on Pseudomonas aeruginosa. The test fungi were more sensitive to the oil, with a MIC range of 0.78~1.56 μL/mL than bacteria in the range which were significantly higher from 0.78 to 25.50 μL/mL.

scholarly journals Antimicrobial Activity of Plant Extracts againstBacillus Subtilis,Staphylococcus Aureusand Escherichia Coli

2011 ◽  
Vol 8 (s1) ◽  
pp. S282-S284 ◽  
Author(s):  
Liliwirianis N ◽  
Wan Zuraida Wan Mohd Zain ◽  
Jamaluddin Kassim ◽  
Shaikh Abdul Karim
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Inhibition Zone ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Stemona Tuberosa ◽  
Elephantopus Scaber

Local herbs have many potential that may be active with antimicrobial activity. A screening was conducted with 11 species of herbs collected in UiTM Pahang Forest Reserve.Epipremnumsp.,Zingibersp.Tetracera indica, Tectaria crenata, Piper stylosum, Homalomena propinque, Goniothalamus sp., Elephantopus scaber, Mapania patiolale, Melastomasp.,Stemona tuberosa, Phullagathis rotundifolia, Thotea grandifoliaandSmilaxsp. were extracted with methanol to obtain their crude. The agar diffusion method using blank disc of 6 mm diameter were loaded with 1000 µg/mL of methanol crude and applied to the inoculate plate was used to assess the antimicrobial activity against two gram positive bacteria (Bacillus subtilisandStaphylococcus aeureus) and one gram negative bacteria (Escherichia coli). The results evaluated as the diameter of the inhibition zone of microbial growth, showed that all the extracts were active against gram-positive bacteria and gram-negative bacteria. The extract ofStemona tuberosewas found to be the most active against theE. coliandS. aeureuswhilePiper stylosumactive againstB. subtilis.

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