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.

Influence of Altered Fatty Acid Composition on Resistance of Listeria monocytogenes to Antimicrobials

1993 ◽  
Vol 56 (4) ◽  
pp. 302-305 ◽  
Author(s):  
V. K. JUNEJA ◽  
P. M. DAVIDSON
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Listeria Monocytogenes ◽  
Acid Composition ◽  
Lipid Composition ◽  
Antimicrobial Agents ◽  
Food Preservation ◽  
Gas Liquid Chromatography ◽  
Antimicrobial Compounds

The sensitivity of Listeria monocytogenes Scott A and ATCC 19114 to antimicrobial compounds was altered when bacterial membrane lipid composition was modified by growth in the presence of added fatty acids. Analysis of cellular fatty acid composition by gas-liquid chromatography indicated that L. monocytogenes Scott A cells contained 0.97, 2.32, 0.81, and 0.72% (relative) of C14:0, C16:0, C18:0, and C18:l, respectively. In the presence of exogenously supplied C14:0, C16:0, C18:0, and C18:l, the percentages increased to 14.03, 30.92, 16.30, and 27.90%. Average MICs for L. monocytogenes Scott A and ATCC 19114 to sodium chloride, tertiary butylhydroquinone, methyl paraben, and propyl paraben were 10.0%, 81, 1406, and 544 μg/ml, respectively. Growing either strain in the presence of 50 μg/ml of either exogenously added C14:0 or C18:0 fatty acids increased their resistance to the four antimicrobial compounds. However, growth in the presence of C18:1 led to increased sensitivity to the antimicrobial agents. The results indicate that the susceptibility of L. monocytogenes to antimicrobial agents is related to the lipid composition of the cell membrane. Consequently, food preservation processes which alter fatty acid composition of L. monocytogenes could result in changes in antimicrobial susceptibility.

Inactivation of chloramphenicol by Gram-negative microorganisms

1968 ◽  
Vol 14 (8) ◽  
pp. 891-899 ◽  
Author(s):  
David Sompolinsky ◽  
Ruth Ziegler-Schlomowitz ◽  
Dora Herczog
Keyword(s):  
Escherichia Coli ◽  
Growth Medium ◽  
Minimal Medium ◽  
Resistance Factor ◽  
The Other ◽  
Gram Negative ◽  
Resistant Strains ◽  
Gram Negative Organisms ◽  
High Level ◽  
Level Resistance

Two derivative strains of Escherichia coli with high-level resistance to chloramphenicol, one carrying an episomal resistance factor and the other a chromosomal mutant, were both shown to be potent inactivators of the drug. When 1 mM chloramphenicol was added to an exponential culture in minimal medium, growth was halted until 85–90% of the drug was inactivated by acylation. At this state the drug was essentially monoacylated. During and after growth, esterification of the second alcoholic group occurred, though at a slower rate. Arylamines, in amounts up to 10% of chloramphenicol equivalents, were demonstrated in the growth medium after 1–3 days' incubation.With an acetateless mutant of Escherichia coli K12, carrying a resistance factor, it was shown that 5–6 moles of acetate was consumed for every mole of chloramphenicol acylated.Inactivation of chloramphenicol by Gram-negative organisms from infections in hospitalized patients was also examined. Among 103 strains susceptible to chloramphenicol, none produced considerable amounts of chloramphenicol esters. The same was the case with 14 resistant strains of Pseudomonas. Of 134 other resistant organisms examined, including strains of Escherichia, Proteus, Klebsiella, Salmonella, and Shigella, 133 were producers of chloramphenicol esters, and in most cases the drug was partly or entirely diacylated.

Resistant Pneumococci Causing Otitis and Sinusitis Failures

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P67-P68
Author(s):  
Michael D Poole
Keyword(s):  
Otitis Media ◽  
Tube Placement ◽  
High Dose ◽  
Young Infants ◽  
Amoxicillin Clavulanate ◽  
Resistance To Penicillin ◽  
Resistant Strains ◽  
High Level ◽  
Number Of Treatment

Objective Describe cases of non-responsive otitis media and rhinosinusitis due to highly resistant strains of Streptococcus pneumoniae. Methods Resistant strains of Streptococcus pneumonia were isolated from cases of non-responsive pediatric otitis media or rhinosinusitis, from September 2005 to September 2008, from a single pediatric otolaryngology practice. Children had failed therapy with “high dose” amoxicillin-clavulanate and/or ceftriaxone injections. Results 54 cases of apparent failed therapy were detected. The strain(s) demonstrated in vitro high level resistance to penicillin, amoxicillin-clavulanate, oral cepahalosporins, trimethoprim-sulfamethoxazole, macrolides, and clindamycin; and were intermediately or fully resistant to ceftriaxone. Serotyping of representative isolated demonstrated these to be 19A pneumococcal isolates. These cases were often in unusually young infants, and often were from a single prolonged episode of acute otitis medi, including 2 cases of mastoiditis with subperiostial abscess. Most of the cases were identified by office-based diagnostic tympanocentesis and were rarely isolated from children undergoing tympanstomy tube placement. All cases resolved after therapy with levofloxacin pediatric suspension (25 mg/ml, 20 mg'kg/day divided BID. Conclusions This is the largest series of otitis and sinusitis cases due to these highly resistant organisms; and these cases suggest that resistant pneumoccocci are likely causing a significant number of treatment failures in the U.S. They are not detected unless nasal or middle ear cultures are taken from treatment failures. Treatment with fluoroquinolones is effective, but raises issues concerning the role of this class of anitbiotics in children.

Lipid Composition and Lipid Synthesis in Guinea Pig Megakaryocytes and Platelets

1979 ◽  
Author(s):  
E.P. Schick ◽  
P.K. Schick
Keyword(s):  
Fatty Acids ◽  
Liquid Chromatography ◽  
Guinea Pig ◽  
Thin Layer ◽  
Lipid Composition ◽  
Guinea Pigs ◽  
Lipid Synthesis ◽  
Gas Liquid Chromatography ◽  
Lipid Phosphorus ◽  
Layer Chromatography

Lipid composition and lipid synthesis have been compared in guinea pig megakaryocytes and platelets. Megakaryocytes were isolated from guinea pigs to 85% purity. Lipids were extracted and were separated by thin layer chromatography. Phospholipid (PL) content was determined by measurement of lipid phosphorus, and cholesterol and fatty acids were quantitated by gas-liquid chromatography. PL composition of megakaryocytes was:PS + PI 15.2%; SM 14.0%; PC 40.1%; PE 30. 6%. PL composition of platelets was: PS 10.1%; PI 4.5%; SM 16.5%; PC 39.5%; PE 29.6%. The cholesterol:PL ratio was 0.35 for megakaryocytes and 0.55 for platelets. The major fatty acids in the PL were: (% of total)Megakaryocytes and platelets were incubated for 1.5 hr with 14C-acetate. Megakaryocytes incorporated acetate into cholesterol and other sterols, ceramide, and PL (0.060, 0.016 and 0.012 nmoles/105 cells). Platelets incorporated acetate into ceramide and PL (0.02 and 0.06 nmoles/109 cells) but only trace amounts into sterols. There appears to be active biosynthesis of cholesterol in megakaryocytes but not in platelets.

scholarly journals High Prevalence of High-Level Ciprofloxacin Resistance in Neisseria gonorrhoeae in Tel Aviv, Israel: Correlation with Response to Therapy

2002 ◽  
Vol 46 (6) ◽  
pp. 1671-1673 ◽  
Author(s):  
Michael Dan ◽  
Francesca Poch ◽  
Bracha Sheinberg
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Response To Therapy ◽  
High Rate ◽  
Sharp Rise ◽  
Tel Aviv ◽  
High Prevalence ◽  
Resistance To Penicillin ◽  
Resistant Strains ◽  
Ciprofloxacin Resistance ◽  
High Level

ABSTRACT A survey of the drug susceptibilities of gonococcal isolates from 100 consecutive patients attending clinics in the Tel Aviv area of Israel during the period from February to September 2000 has shown a 61% rate of ciprofloxacin resistance (MICs, ≥1 μg/ml); 51 isolates were highly resistant (MICs, ≥4 μg/ml). Ciprofloxacin-resistant strains were more prevalent among isolates with chromosomally mediated resistance to penicillin and tetracycline. Therapeutic failures with ciprofloxacin correlated with MICs of ≥1 mg/ml (P < 0.01). The high rate of ciprofloxacin resistance coinciding with a sharp rise in the incidence of gonorrhea precludes the use of fluoroquinolone drugs for the empirical treatment of gonococcal infections acquired in Israel.

scholarly journals The Changes in the Lipid Composition of Mung Bean Seeds as Affected by Processing Methods

2007 ◽  
Vol 3 (5) ◽  
Author(s):  
El-Sayed Ali Abdel-Rahman ◽  
Fawzy A El-Fishawy ◽  
Mohamed A El-Geddawy ◽  
Tomas Kurz ◽  
Mohamed N El-Rify
Keyword(s):  
Fatty Acids ◽  
Lipid Composition ◽  
Mung Bean ◽  
Unsaturated Fatty Acids ◽  
Essential Fatty Acids ◽  
Saturated Fatty Acids ◽  
Gas Liquid Chromatography ◽  
Lipid Fractions ◽  
Total Fatty Acids ◽  
Tlc Analysis

This study was conducted to assess in detail the possible effects of some technological processes such as soaking, germination, cooking, soaking + cooking, and germination + cooking on the lipid composition of mung bean seeds of Giza 1 variety. TLC analysis of mung bean lipids showed that the phospholipids and triglycerides recorded the highest percentage among lipid fractions (32.26 and 30.10%), while the 1,3 diglycerides constituted the least percentage (2.80%) in mung bean seeds. The soaking, germination and cooking processes caused a decrease in the phospholipids, triglycerides and hydrocarbons accompanied with an increase in monoglycerides, 1,2-(2,3)-diglycerides, sterols and free fatty acids. Eleven fractions were separated from phospholipids class of the studied samples; seven of these fractions were identified. The major component of phospholipids was phosphatidyl choline, amounting to 21.30, 17.84, 16.21, 13.87, 13.20 and 11.47% of the total phospholipids in raw, soaked, germinated, raw-cooked, soaked-cooked and germinated-cooked mung bean seeds, respectively. Gas liquid chromatography of the total lipids of mung bean seeds showed that the unsaturated fatty acids represented 69.58, 64.35, 63.3, 63.16, 61.84 and 61.12%, while the levels of saturated fatty acids were low being 30.37, 34.05, 35.66, 34.64, 37.93 and 38.75% of the total fatty acids in raw, soaked, germinated, raw-cooked, soaked-cooked and germinated-cooked, respectively. The total essential fatty acids (linoleic and linolenic) represented the highest proportion of fatty acids (50.10% of the total fatty acids).

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 Impaired fetal erythrocytes' filterability: relationship with cell size, membrane fluidity, and membrane lipid composition

Blood ◽  
1992 ◽  
Vol 79 (8) ◽  
pp. 2148-2153 ◽  
Author(s):  
FC Colin ◽  
Y Gallois ◽  
D Rapin ◽  
A Meskar ◽  
JJ Chabaud ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Membrane Fluidity ◽  
Lipid Composition ◽  
Fluorescence Polarization ◽  
High Performance ◽  
Unsaturated Fatty Acids ◽  
Membrane Lipid ◽  
Gas Liquid Chromatography ◽  
Biophysical Parameters ◽  
Membrane Lipid Composition

Abstract The lipid composition of erythrocytes (red blood cells [RBCs]) plays a significant role in determining certain membrane biophysical properties. We have found that fetal RBCs showed a dramatically low filterability compared with adult RBCs and questioned whether this could be a consequence of their membrane lipid composition. We therefore studied fetal RBCs at two different gestational ages, neonatal RBCs and adult RBCs. Biophysical parameters were studied using two different techniques, filterability and membrane fluidity. The latter was measured by fluorescence polarization using three different probes. The membrane lipid composition was examined by measuring cholesterol and phospholipids. After extraction of the phospholipids, followed by high performance thin-layer chromatography, the fatty acids in the phospholipid subfractions were analyzed by gas-liquid chromatography. The fetal RBCs' filterability was found to be correlated with both the larger size and the higher hemoglobin content of the cells, but there was no correlation between RBC filterability and fluidity or membrane lipid composition. In adult RBCs, compared with neonatal RBCs, the slight increase of unsaturated fatty acids in phosphatidylcholine and phosphatidylethanolamine should have increased the membrane fluidity. However, in RBCs, no change was observed in the fluidity parameters measured by fluorescence polarization.

scholarly journals The distribution of the DHFR genes in trimethoprim-resistant urinary tract isolates from Taiwan

1992 ◽  
Vol 109 (3) ◽  
pp. 453-462 ◽  
Author(s):  
Lin-Li Chang ◽  
Shui-Feng Chang ◽  
Teh-Yuan Chow ◽  
Wen-Jeng Wu ◽  
Jong-Chou Chang
Keyword(s):  
Escherichia Coli ◽  
Dihydrofolate Reductase ◽  
Type I ◽  
Type Ii ◽  
Colony Hybridization ◽  
Resistant Strains ◽  
High Level ◽  
Type V ◽  
Urinary Isolates ◽  
Level Resistance

SUMMARYBetween July 1987 and June 1989, 1054 urinary isolates of enterobacteria from Kaohsiung, Taiwan were studied for their trimethoprim resistance. Trimethoprim resistance was defined as MIC greater than 4 μg/ml and high-level resistance by MIC greater than 1000 μg/ml. The incidence of trimethoprim resistance increased from 33·6% in 1987 to 42·1% in 1989. Among the resistant strains studied, 90% were resistant to high levels of trimethoprim. An increase in the proportion of resistant strains (33·9–46·3%) exhibiting high-level non-transferable trimethoprim resistance was noted. The distribution of the dihydrofolate reductase (DHFR) genes by colony hybridization in 374 trimethoprim-resistant isolates revealed the presence of type I and type V DHFR genes in most of these isolates (45·4% and 10·4% respectively). Type I was predominant inEscherichia coliwhereas type V was frequently seen inEnterobacterspp. None showed homology with the type II and type III DHFR probe DNA. In addition, transposon Tn7 was present in 7·8% of 374 trimethoprim-resistant enterobacteria.

scholarly journals The glycolipids of Lactobacillus casei A.T.C.C. 7469

1968 ◽  
Vol 107 (4) ◽  
pp. 491-496 ◽  
Author(s):  
N. Shaw ◽  
K. Heatherington ◽  
J Baddiley
Keyword(s):  
Fatty Acids ◽  
Lactobacillus Casei ◽  
Octadecenoic Acid ◽  
Deae Cellulose ◽  
Minor Component ◽  
Gas Liquid Chromatography ◽  
Chloroform Methanol ◽  
Hydrolysis Of ◽  
Lactobacillic Acid ◽  
Acetate Form

1. The lipids were extracted from Lactobacillus casei A.T.C.C. 7469 with chloroform–methanol mixtures. The glycolipids were obtained by chromatography on silicic acid and DEAE-cellulose (acetate form). 2. Hydrolysis of the glycolipids with alkali gave two glycerol glycosides and a mixture of fatty acids. 3. The glycosides were separated and their structures elucidated. The major component was O-α-d-galactopyranosyl-(1→2)-O-α-d-glucopyranosyl-(1→1)-glycerol and the minor component O-α-d-glucopyranosyl-(1→6)-O-α-d-galactopyranosyl-(1→2)-O-α-d-glucopyranosyl-(1→1)-glycerol. 4. Analysis of the fatty acids by gas–liquid chromatography showed that they were predominantly palmitic acid, octadecenoic acid and lactobacillic acid.

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