Lipids of antibiotic-resistant and -susceptible members of the Enterobacteriaceae

1977 ◽  
Vol 23 (8) ◽  
pp. 1045-1051 ◽  
Author(s):  
William J. Suling ◽  
William M. O'Leary
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Analysis ◽  
Lower Amount ◽  
Bacterial Strains ◽  
Antibiotic Resistant ◽  
Cyclopropane Fatty Acids ◽  
Resistant Strains ◽  
Lower Ratio ◽  
Layer Chromatography ◽  
Chloroform Methanol

Lipids of antibiotic-resistant and related -susceptible strains of the Enterobacteriaceae were extracted with chloroform–methanol and characterized by thin-layer chromatography, densitometry, and fatty acid analysis using gas chromatography. Quantitative differences which correlated with antibiotic resistance existed among the phospholipids and fatty acids. A relatively higher concentration of a ninhydrin-positive phospholipid concomitant with a lower amount of phosphatidylethanolamine was observed in antibiotic-resistant strains of Serratia marcescens. Bacterial strains which harbored R-factor 222 had a higher ratio of phosphatidylglycerol to diphosphatidylglycerol than their respective parent strains while those strains which were resistant to the polymyxins had a lower ratio of these phospholipids. Differences in the relative amounts of certain unsaturated and cyclopropane fatty acids were observed between susceptible and resistant strains. Such differences, however, were dependent upon a particular genus and species.

scholarly journals THE ULTRASTRUCTURE OF LIPID-DEPLETED ROD PHOTORECEPTOR MEMBRANES

1974 ◽  
Vol 63 (2) ◽  
pp. 587-598 ◽  
Author(s):  
Izhak Nir ◽  
Michael O. Hall
Keyword(s):  
Lipid Extraction ◽  
Fatty Acid Analysis ◽  
Major Protein ◽  
Rod Photoreceptor ◽  
Thin Sections ◽  
Retinal Rod ◽  
Layer Chromatography ◽  
Chloroform Methanol ◽  
Photoreceptor Membranes

The structure of lipid-depleted retinal rod photoreceptor membranes was studied by means of electron microscopy. Aldehyde-fixed retinas were exhaustively extracted with acetone, chloroform-methanol, and acidified chloroform-methanol. The effect of prefixation on the extractability of lipids was evaluated by means of thin-layer chromatography and fatty acid analysis. Prefixation with glutaraldehyde rendered 38% of the phospholipids unextractable, while only 7% were unextractable after formaldehyde fixation. Embedding the retina in a lipid-retaining, polymerizable glutaraldehyde-urea mixture allows a comparison of the interaction of OsO4 with lipid-depleted membranes and rod disk membranes which contain all their lipids. A decrease in electron density and a deterioration of membrane fine structure in lipid-depleted tissue are correlated with the extent of lipid extraction. These observations are indicative of the role of the lipid bilayer in the ultrastructural visualization of membrane structure with OsO4. Negatively stained thin sections of extracted tissue reveal substructures in the lipid-depleted rod membranes. These substructures are probably the opsin molecules which are the major protein component of retinal rod photoreceptor membranes.

Standardization of Homoeopathic Mother Tincture of Strychnous nux vomica with the help of High-Performance Thin Layer Chromatography and correlation of its alkaloid markers with its Toxicological action

2021 ◽  
pp. 4203-4206
Author(s):  
Dharmendra B. Sharma ◽  
Parth Aphale ◽  
Vineet Sinnarkar ◽  
Sohan S. Chitlange ◽  
Asha Thomas
Keyword(s):  
Fatty Acids ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Therapeutic Action ◽  
Aluminium Sheets ◽  
Mother Tincture ◽  
Layer Chromatography ◽  
Chloroform Methanol ◽  
Dark Blue

Background: Chromatography is one of the important laboratory technique in which the components of a mixture are separated on an adsorbent in order to analyze, identify, purify and quantify a mixture. Thin Layer Chromatography (TLC)is used to support the identity of a compound in a mixture when the Rf of a compound is compared with the Rf of a known compound. High Performance Thin Layer Chromatography is a sophisticated and automated form of Thin Layer Chromatography (TLC). The procedure simultaneously processes the sample and standard that results in better analytical precision and accuracy at a faster pace. Pharmacological/ Toxicological action of Nux Vomica is because of its active principles present in the seeds namely strychnine, brucine etc. This research paper aims to corelate the active principles present in Nux Vomica with the toxicological action of the same. Materials and Methods: 1. Standard Nux Vomica mother tincture was tested for its alkaloid markers and its correlation with the toxicological action was studied. 2. Analysis of the mother tincture was done using High Performance Thin Layer Chromatography. 3. Stationary phase consisted of TLC Aluminium sheets with silica gel 60 F253 pre-coated layer (20cm x 10cm), thickness-0.2mm, no. of tracks-18, band length-6mm. 4. Mobile Phase consisted of Chloroform: Methanol (9.5:0.5). 5. The plate was developed in developing chamber and observed under U.V. Light. Results: Colours seen on the HPTLC Plates of samples are greenwhich corresponds to strychnine, dark blue which corresponds to brucine, orange to alkaloids fluorescent green to sterols and pink to fatty acids which are evident on the chromatogram. Conclusion: Therapeutic action of Nux Vomica as noted in Homoeopathic Materia Medica is because of the active principles like strychnine, brucine, alkaloids, sterols, fatty acids present in it which is evident from the chromatogram.

Comparison of the activity spectra against pathogens of bacterial strains producing a mutacin or a lantibiotic

2001 ◽  
Vol 47 (4) ◽  
pp. 322-331 ◽  
Author(s):  
Hélène Morency ◽  
Marilaine Mota-Meira ◽  
Gisèle LaPointe ◽  
Christophe Lacroix ◽  
Marc C Lavoie
Keyword(s):  
Drug Resistance ◽  
Campylobacter Jejuni ◽  
Bacterial Pathogens ◽  
The Other ◽  
Bacterial Strains ◽  
Antibiotic Resistant ◽  
Major Threat ◽  
Antibiotic Compounds ◽  
Resistant Strains ◽  
Further Development

The increase of drug resistance among bacterial pathogens is currently a major threat in hospital settings. New and more efficient antibiotic compounds have to be developed to fight infectious diseases. In the present work, a deferred antagonism test was used to determine the activity of different bacterial strains producing either a mutacin or a lantibiotic against bacterial pathogens. The mutacins A, B, C, D, I, K, L, M, and nisins A and Z were active against all enterococci tested. Mutacins A and B, and nisins A and Z inhibited all the staphylococci tested. Except for the strains producing mutacins P, Q, and X, all the other producing strains inhibited the streptococci tested. Mutacins A, B, I, J, T, nisins A and Z, and epidermin inhibited the two antibiotic-resistant strains of Neisseria gonorrhoeae tested. Mutacins A, B, C, D, and nisins A and Z inhibited Campylobacter jejuni and Helicobacter pylori. Thus, the wide activity spectra of nisin A and Z are confirmed. These results also indicate that many of the mutacins, especially those of groups A, B, C, D, I, J, K, L, M, and T, could be candidates for further development as useful antibiotics.Key words: mutacin, lantibiotic, bacteriocin, antibiotic.

Lipid composition of Escherichia coli in relation to resistance to penicillin

1978 ◽  
Vol 24 (3) ◽  
pp. 245-253 ◽  
Author(s):  
Nicholas J. Legakis ◽  
Nicholas P. Protopappas ◽  
John G. Leonardopoulos ◽  
John Th. Papavassiliou
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Lipid Composition ◽  
Gas Liquid Chromatography ◽  
Triglyceride Fraction ◽  
Bound Lipids ◽  
Resistance To Penicillin ◽  
Resistant Strains ◽  
High Level ◽  
Chloroform Methanol

Clinical isolates of Escherichia coli sensitive and resistant to penicillin were compared in lipid composition and 14C-labelled penicillin uptake, as possible factors in resistance.Except for a slight increase in the triglyceride fraction in sensitive strains there were no qualitative or quantitative differences in the classes of extractable lipids present. Gas–liquid chromatography of the phospholipid and triglyceride fatty acids of the polar and non-polar fatty acids of the bound lipids showed that the same kinds of fatty acids were present. There was an increase of myristate in the chloroform–methanol extractable lipids of highly resistant strains accompanied by a rather general decrease of the other fatty acids. Gas-chromatographic analysis of the polar-bound lipids showed an increase of the β-hydroxydecanoic acid in the resistant strains.By studying the uptake of 14C-labelled benzylpenicillin and the crypticity of the β-lactamase, evidence has been produced that a decreased permeability of resistant strains to penicillin cooperates with β-lactamase to induce a high level of resistance. The altered lipid metabolism may reflect the special architectural changes in the cell wall which cause decreased permeability.

scholarly journals Antibacterial Role of SO42− , NO3− , C2O42− and CH3CO2− Anions on Cu(II) and Zn(II) Complexes of a Thiadiazole-derived Pyrrolyl Schiff Base

2002 ◽  
Vol 8 (5) ◽  
pp. 263-267 ◽  
Author(s):  
Zahid H. Chohan ◽  
Humayun Pervez ◽  
Abdul Rauf ◽  
Claudiu T. Supuran
Keyword(s):  
Schiff Base ◽  
Metal Ion ◽  
Condensation Reaction ◽  
Analytical Data ◽  
Bacterial Strains ◽  
Antibiotic Resistant ◽  
Novel Approach ◽  
Resistant Strains ◽  
New Compounds

A condensation reaction of 2-amino-1,3,4-thiadiazole with 2-pyrrolecarboxaldehyde to form tridentate NNN donor Schiff base has been performed. The prepared Schiff base was further used for the formation of metal complexes having stoichiometry [M(L)2]Xn , where M=Cu(II) or Zn(II), L=N-(2-pyrrolylmethylene)-2-amino-1,3,4-thiadiazole, X=SO42− , NO3− , C2O42− or CH3CO2− and n=1 or 2. The new compounds described here have been characterized by their physical, spectral and analytical data, and have been screened against several bacterial strains such as Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The antibacterial potency of the Schiff base increased upon chelation/complexation, having the same metal ion (cation) but different anions opening up a novel approach in finding new ways to fight against antibiotic resistant strains.

scholarly journals Naturally-Occurring Alkaloids of Plant Origin as Potential Antimicrobials against Antibiotic-Resistant Infections

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3619
Author(s):  
Bruno Casciaro ◽  
Laura Mangiardi ◽  
Floriana Cappiello ◽  
Isabella Romeo ◽  
Maria Rosa Loffredo ◽  
...  
Keyword(s):  
Chemical Potential ◽  
Higher Plants ◽  
Antimicrobial Activities ◽  
New Drugs ◽  
Bacterial Strains ◽  
Antibiotic Resistant ◽  
Naturally Occurring ◽  
Resistant Strains ◽  
Function Relationship ◽  
Conventional Antibiotics

Antibiotic resistance is now considered a worldwide problem that puts public health at risk. The onset of bacterial strains resistant to conventional antibiotics and the scarcity of new drugs have prompted scientific research to re-evaluate natural products as molecules with high biological and chemical potential. A class of natural compounds of significant importance is represented by alkaloids derived from higher plants. In this review, we have collected data obtained from various research groups on the antimicrobial activities of these alkaloids against conventional antibiotic-resistant strains. In addition, the structure–function relationship was described and commented on, highlighting the high potential of alkaloids as antimicrobials.

scholarly journals Efficiency of combined action of antimicrobial preparations against poly-resistant strains of conditionally-pathogenic bacteria isolated from wounds of surgery patients

2020 ◽  
Vol 11 (3) ◽  
Author(s):  
T. V. Sklyar ◽  
K. V. Lavrentievа ◽  
O. M. Rudas ◽  
О. V. Bilotserkivska ◽  
N. V. Kurahina ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Disk Diffusion Method ◽  
Antibiotic Resistant ◽  
Simultaneous Application ◽  
Strategic Approach ◽  
Resistant Strains

The strategy of use of combination therapy of antibacterial preparations is being broadly introduced to clinical practice to fight bacterial infections caused by poly-resistant strains of microorganisms. From the wounds of surgery patients, we isolated 67 clinical strains of conditionally-pathogenic bacteria identified as Staphylococcus aureus, S. epidermidis, Escherichia coli, Klebsiella pneumoniaе, Proteus vulgaris, Proteus mirabilis, Pseudomonas aeruginosa. Using disk diffusion method, the isolated bacterial strains were found to be most resistant to penicillin preparations: ampicillin, oxacillin, amoxicillin/clavulanat; tetracycline and cephalosporin of the II generation – cefoxitin. The percentage of strains insusceptible to these antibacterial preparations accounted for 65.0%. The division of antibiotic-resistant cultures regarding phenotype groups according to the level of their antibiotic resistance allowed determination of 4 PDR-, 8 XDR- and 14 MDR-strains. During the studies on experimental determining of MIC of antibiotic and antiseptics in the condition of applying them as monopreparations against isolated bacterial cultures, we saw significant exceess in the threshold values of MIC, and, first of all, regarding pandrug-resistant and extensive drug-resistant clinical microbial isolates. Use of combinations of antibacterial preparations was found to show the synergic effect of antibiotics (ceftriaxone, ofloxacin, gentamicin) and antiseptics (chlorhexidine, decasan), which is expressed in simultaneous decrease in MIC of each of the tested preparations by 2–8 times compared with their isolative application. Such combinatory approach regarding simultaneous application of antibacterial preparations may be considered as one of the most promising ways to combat poly-resistant clinical isolates of conditionally-pathogenic microorganisms and to offer a new strategic approach to prevention of spread of antibiotic resistance as a phenomenon in medical practice.

scholarly journals Exacerbations of Chronic Rhinosinusitis—Microbiology and Perspectives of Phage Therapy

Antibiotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 175 ◽  
Author(s):  
Szaleniec ◽  
Gibała ◽  
Pobiega ◽  
Parasion ◽  
Składzień ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Chronic Rhinosinusitis ◽  
Phage Therapy ◽  
Specific Treatment ◽  
Bacterial Strains ◽  
Coagulase Negative Staphylococci ◽  
Antibiotic Resistant ◽  
First Choice ◽  
Acute Bacterial Rhinosinusitis ◽  
Resistant Strains

The chronically inflamed mucosa in patients with chronic rhinosinusitis (CRS) can additionally be infected by bacteria, which results in an acute exacerbation of the disease (AECRS). Currently, AECRS is universally treated with antibiotics following the guidelines for acute bacterial rhinosinusitis (ABRS), as our understanding of its microbiology is insufficient to establish specific treatment recommendations. Unfortunately, antibiotics frequently fail to control the symptoms of AECRS due to biofilm formation, disruption of the natural microbiota, and arising antibiotic resistance. These issues can potentially be addressed by phage therapy. In this study, the endoscopically-guided cultures were postoperatively obtained from 50 patients in order to explore the microbiology of AECRS, evaluate options for antibiotic treatment, and, most importantly, assess a possibility of efficient phage therapy. Staphylococcus aureus and coagulase-negative staphylococci were the most frequently isolated bacteria, followed by Haemophilus influenzae, Pseudomonas aeruginosa, and Enterobacteriaceae. Alarmingly, mechanisms of antibiotic resistance were detected in the isolates from 46% of the patients. Bacteria not sensitive to amoxicillin were carried by 28% of the patients. The lowest rates of resistance were noted for fluoroquinolones and aminoglycosides. Fortunately, 60% of the patients carried bacterial strains that were sensitive to bacteriophages from the Biophage Pharma collection and 81% of the antibiotic-resistant strains turned out to be sensitive to bacteriophages. The results showed that microbiology of AECRS is distinct from ABRS and amoxicillin should not be the antibiotic of first choice. Currently available bacteriophages could be used instead of antibiotics or as an adjunct to antibiotics in the majority of patients with AECRS.

scholarly journals Therapeutic potential of bacteriophage in treating Klebsiella pneumoniae B5055-mediated lobar pneumonia in mice

2008 ◽  
Vol 57 (12) ◽  
pp. 1508-1513 ◽  
Author(s):  
Sanjay Chhibber ◽  
Sandeep Kaur ◽  
Seema Kumari
Keyword(s):  
Klebsiella Pneumoniae ◽  
Therapeutic Agent ◽  
Phage Therapy ◽  
Therapeutic Potential ◽  
Respiratory Infections ◽  
Multidrug Resistant ◽  
Bacterial Strains ◽  
Antibiotic Resistant ◽  
Lobar Pneumonia ◽  
Resistant Strains

Klebsiella pneumoniae causes infections in humans especially in immunocompromised patients. About 80 % of nosocomial infections caused by K. pneumoniae are due to multidrug-resistant strains. The emergence of antibiotic-resistant bacterial strains necessitates the exploration of alternative antibacterial therapies, which led our group to study the ability of bacterial viruses (known as bacteriophages or simply phages) to treat mice challenged with K. pneumoniae. Phage SS specific for K. pneumoniae B5055 was isolated and characterized, and its potential as a therapeutic agent was evaluated in an experimental model of K. pneumoniae-mediated lobar pneumonia in mice. Mice were challenged by intranasal (i.n.) inoculation with bacteria (108 c.f.u. ml−1). A single intraperitoneal injection of 1010 p.f.u. ml−1 phage administered immediately after i.n. challenge was sufficient to rescue 100 % of animals from K. pneumoniae-mediated respiratory infections. Administration of the phage preparation 3 h prior to i.n. bacterial challenge provided significant protection in infected mice, while even 6 h delay of phage administration after the induction of infection rendered the phage treatment ineffective. The results of this study therefore suggest that the timing of starting the phage therapy after initiation of infection significantly contributes towards the success of the treatment.

scholarly journals Antibacterial Co(II), Cu(II), Ni(II) and Zn(II) Complexes of Thiadiazoles Schiff Bases

2001 ◽  
Vol 8 (2) ◽  
pp. 95-101 ◽  
Author(s):  
Zahid H. Chohan ◽  
Maimoon F. Jaffery ◽  
Claudiu T. Supuran
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Schiff Bases ◽  
Bacterial Species ◽  
Analytical Data ◽  
Bacterial Strains ◽  
Antibiotic Resistant ◽  
Resistant Strains ◽  
New Compounds

Schiff bases were obtained by condensation of 2-amino-l,3,4-thiadiazole with 5-substituted-salicylaldehydes which were further used to obtain complexes of the type [M(L)2]Cl2, where M=Co(II), Cu(II), Ni(II) or Zn(II). The new compounds described here have been characterized by physical, spectral and analytical data, and have been screened for antibacterial activity against several bacterial strains such as Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The antibacterial potency of these Schiff bases increased upon chelation/complexation, against the tested bacterial species, opening new aproaches in the fight against antibiotic resistant strains.

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