THE CONVERSION OF 2,6-DIAMINOPIMELIC ACID-1,7-C14TO LYSINE-1-C14BY CERTAIN BACTERIA

1961 ◽  
Vol 39 (10) ◽  
pp. 1551-1558 ◽  
Author(s):  
A. J. Finlayson ◽  
F. J. Simpson
Keyword(s):  
Escherichia Coli ◽  
Aspergillus Flavus ◽  
Culture Medium ◽  
Leuconostoc Mesenteroides ◽  
Streptomyces Griseus ◽  
Diaminopimelic Acid ◽  
Proteus Vulgaris ◽  
E Coli ◽  
Carbon 14 ◽  
Carboxyl Carbon

When 2,6-diaminopimelicacid-1,7-C14was added to growing cultures of Bacillus megaterium, Staphlococcus aureus, and Escherichia coli, 8–9% of added carbon-14 appeared in the cellular lysine. Similar experiments with Proteus vulgaris, Streptomyces griseus, Aspergillus flavus, and Lactobacillus arabinosus resulted in less than 0.3% of the added carbon-14 being incorporated into the cellular lysine. Leuconostoc mesenteroides converted 0.6% of the added DAP-1,7-C14to lysine-1-C14.Over 90% of the carbon-14 in cell lysine from B. megaterium and L. mesenteroides was found in the carboxyl carbon. This was interpreted as indicating a direct decarboxylation of DAP-1,7-C14to lysine-1-C14. About 70% of the carbon-14 in the lysine from cells of S. aureus and E. coli was found in the carboxyl carbon, thus suggesting that some lysine comes from sources other than 2,6-diaminopimelic acid.Those organisms that actively decarboxylated DAP-1,7-C14to form lysine-C14also synthesized DAP and excreted it into the culture medium during growth.

Антимікробна резистентність провідних збудників інфекцій сечових шляхів у Києві (Україна)

2017 ◽  
Vol 1 (2) ◽  
pp. 48-60
Author(s):  
A.G. Salmanov ◽  
A.V. Rudenko
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Staphylococcus Epidermidis ◽  
Klebsiella Oxytoca ◽  
Enterobacter Aerogenes ◽  
Enterobacter Cloacae ◽  
Proteus Vulgaris ◽  
Providencia Rettgeri ◽  
E Coli

Мета роботи — вивчити резистентність до антибіотиків бактеріальних збудників інфекцій сечових шляхів (ІСШ), виділених у пацієнтів урологічного стаціонару в м. Києві. Матеріали і методи. Досліджено 1612 штамів бактерій, виділених із сечі хворих з ІСШ (цистит, уретрит, пієлонефрит), госпіталізованих в урологічне відділення ДУ «Інститут урології НАМН України» у м. Києві протягом 2016 р. Серед пацієнтів переважали жінки — 1201 (74,5 %). Вік хворих становив від 17 до 74 років. Для збору даних використано медичну документацію лікарні. Мікробіологічні дослідження виконано у лабораторії мікробіології ДУ «Інститут урології НАМН України». Аналізували результати культурального дослідження зразків сечі, зібраних за наявності клінічних ознак ІСШ. Дослідження клінічного матеріалу та інтерпретацію отриманих результатів проводили загальноприйнятими методами. Вивчено чутливість уропатогенів до 31 антибіотика дискодифузійним методом відповідно до рекомендацій Інституту клінічних та лабораторних стандартів США (Clinical and Laboratory Standards Institute (CLSI)). Результати та обговорення. Аналіз мікробного спектра сечі виявив домінування серед уропатогенів штамів Escherichia coli (32,0 %), Enterococcus faecalis (19,5 %), Klebsiella pneumoniae (10,9 %), Staphylococcus epidermidis (8,9 %), S. haemolyticus (6,5 %) та Pseudomonas aeruginosa (6,4 %). Частка Enterococcus faecium, Enterobacter aerogenes і Streptococcus viridans становила відповідно 2,5, 2,2 і 1,6 %, Enterobacter cloacae, Klebsiella oxytoca, Acinetobacter baumannii, Proteus vulgaris та Providencia rettgeri — менше 1,0 %. У більшості випадків (69,7 %) мікроорганізми виділено у монокультурі, у решті випадків — у мікробних асоціа- ціях. Високу резистентність до тестованих антибіотиків виявили штами E. aerogenes (45,1 %), E. cloacae (45,7 %), E. faecium (40,9 %), E. faecalis (40,7 %), E. coli (39,9 %), P. aeruginosa (34,0 %), K. pneumoniae (28,6 %). Найбільш активними до уропатогенів були іміпенем (E. coli — 87,6 %, P. aeruginosa — 75,7 %, E. cloacae — 67,3 %, E. aerogenes — 72,6 %, K. pneumoniae — 93,2 %), меропенем (E. coli — 89,1 %, P. aeruginosa — 76,7 %, K. pneumoniae — 82,6 %), лефлоцин (E. coli — 74,5 %, ентерококи — 78,7 %, P. aeruginosa — 76,7 %, E. cloacae — 73,9 %, E. aerogenes — 80,4 %, K. pneumoniae — 83,5 %), амоксицилін/клавуланат (ентерококи — 84,6 %), фурагін (ентерококи — 82,6 %), цефоперазон (K. pneumoniae — 89,2 %, P. aeruginosa — 73,8 %), цефтріаксон (K. pneumoniae — 80,1 %). Висновки. Антибіотикорезистентність збудників ІСШ — важлива терапевтична проблема. Найбільшою активністю до уропатогенів характеризуються іміпенем, меропенем, лефлоцин, амоксицилін/ клавуланат, фурагін, цефоперазон, цефтріаксон, які можна розглядати як препарат вибору для призначення стартової терапії ІСШ. Необхідно здійснювати постійний моніторинг за резистентністю до дії антибіотиків. Політику використання антибіотиків у кожному стаціонарі слід визначати залежно від локальних даних щодо резистентності до протимікробних препаратів.

scholarly journals Uropathogenic Escherichia coli Biofilm-Forming Capabilities are not Predictable from Clinical Details or from Colonial Morphology

Diseases ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 11 ◽  
Author(s):  
Shane Whelan ◽  
Mary Claire O’Grady ◽  
Dan Corcoran ◽  
Karen Finn ◽  
Brigid Lucey
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Culture Medium ◽  
Recurrent Infection ◽  
Positive Control ◽  
Uropathogenic Escherichia Coli ◽  
E Coli ◽  
Recurrent Uti ◽  
Colonial Morphology ◽  
The Difference

Antibiotic resistance is increasing to an extent where efficacy is not guaranteed when treating infection. Biofilm formation has been shown to complicate treatment, whereby the formation of biofilm is associated with higher minimum inhibitory concentration values of antibiotic. The objective of the current paper was to determine whether biofilm formation is variable among uropathogenic Escherichia coli isolates and whether formation is associated with recurrent urinary tract infection (UTI), and whether it can be predicted by phenotypic appearance on culture medium A total of 62 E. coli isolates that were reported as the causative agent of UTI were studied (33 from patients denoted as having recurrent UTI and 29 from patients not specified as having recurrent UTI). The biofilm forming capability was determined using a standard microtitre plate method, using E. coli ATCC 25922 as the positive control. The majority of isolates (93.6%) were found to be biofilm formers, whereby 81% were denoted as strong or very strong producers of biofilm when compared to the positive control. Through the use of a Wilcox test, the difference in biofilm forming propensity between the two patient populations was found to not be statistically significant (p = 0.5). Furthermore, it was noted that colony morphology was not a reliable predictor of biofilm-forming propensity. The findings of this study indicate that biofilm formation is very common among uropathogens, and they suggest that the biofilm-forming capability might be considered when treating UTI. Clinical details indicating a recurrent infection were not predictors of biofilm formation.

scholarly journals EnteroaggregativeEscherichia coliassociated with an outbreak of diarrhoea in a neonatal nursery ward

1996 ◽  
Vol 117 (1) ◽  
pp. 11-16 ◽  
Author(s):  
M. Čobeljić ◽  
B. Miljković-Selimović ◽  
D. Paunović-Todosijević ◽  
Z. Veličković ◽  
Z. Lepšanović ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Liquid Culture ◽  
Culture Medium ◽  
Multiple Antibiotic Resistance ◽  
E Coli ◽  
Source Of Infection ◽  
Liquid Culture Medium ◽  
Aggregative Adherence ◽  
Mode Of Transmission ◽  
Age Range

SummaryOver a 9-day period in February 1995, 16 newborn babies (age range 2–11 days) and 3 infants (24, 47 and 180 days of age) in a neonatal nursery ward developed diarrhoea accompanied by pyrexia and weight loss. Known enteropathogens were not detected in their stools butEscherichia colidisplaying aggregative adherence to HEp-2 cells (enteroaggregativeE. coli) were found in 12 (63%) ill infants and in none of 5 well neonates (P= 0·02). The illness lasted 3–9 days (mean 5·2) in 16 babies, whereas in 3 neonates it showed a protracted course of 18–20 days. The source of infection and the mode of transmission remained unclear. The outbreak isolates manifested properties common in this new group of diarrhoeagenicE. coli: mannose-resistant haemagglutination, haemolysis on blood agar, and clump formation in liquid culture medium. They belonged to the O4E. coliserogroup and expressed multiple antibiotic resistance.

scholarly journals Thành phần hóa học và hoạt tính kháng vi sinh vật gây bệnh của tinh dầu vỏ bưởi Năm Roi (Citrus grandis (L.) Osbeck)

2021 ◽  
Vol 57 (Food Technology) ◽  
pp. 189-195
Author(s):  
Huỳnh Xuân Phong ◽  
Kim Ngân Mai ◽  
Thị Thảo Nguyên Trần ◽  
Minh Châu Lưu ◽  
Nguyễn Ngọc Thạnh ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacillus Cereus ◽  
Aspergillus Flavus ◽  
E Coli

Nghiên cứu này thực hiện nhằm xác định thành phần hóa học và khảo sát được các hoạt tính kháng vi sinh vật gây bệnh của tinh dầu vỏ bưởi Năm Roi (Citrus grandis (L.) Osbeck) được ly trích bằng phương pháp chưng cất lôi cuốn hơi nước. Khảo sát khả năng kháng khuẩn của tinh dầu với vi khuẩn Staphylococcus aureus, Bacillus cereus và Escherichia coli bằng phương pháp khuếch tán giếng thạch với nồng độ tinh dầu (50%, 25%, 10% và 5%). Đánh giá khả năng kháng nấm mốc được thực hiện với Aspergillus flavus bằng phương pháp khuếch tán giếng thạch. Kết quả cho thấy hiệu suất tinh dầu thu được 1,78%, xác định được 25 thành phần chính trong tinh dầu vỏ bưởi Năm Roi như các hợp chất terpen, rượu và aldehyde. Khả năng kháng 3 chủng vi khuẩn S. aureus, B. cereus và E. coli ở nồng độ tinh dầu 50% đường kính vòng kháng vô khuẩn lần lượt là 15,67 ± 0,76 mm, 14,00 ± 0,92 mm và 12,33 ± 0,57 mm; ở nồng độ 25% là 13,33 ± 0,58 mm, 11,00 ± 0,87 mm và 9,33 ± 0,58 mm. Kết quả kháng nấm mốc A. flavus với hiệu suất kháng nấm ở nồng độ tinh dầu 50%, 25%, 10% và 5% lần lượt là 81,24 ± 2,25%, 62,58± 2,04%, 26,19 ± 2,02% và 8,35 ± 2,24%.

scholarly journals The N-Acetyl-d-Glucosamine Kinase of Escherichia coli and Its Role in Murein Recycling

2004 ◽  
Vol 186 (21) ◽  
pp. 7273-7279 ◽  
Author(s):  
Tsuyoshi Uehara ◽  
James T. Park
Keyword(s):  
Escherichia Coli ◽  
Deletion Mutant ◽  
Alternative Pathway ◽  
Side Wall ◽  
Cell Extract ◽  
Diaminopimelic Acid ◽  
Terminal Sequence ◽  
E Coli ◽  
Cell Extracts ◽  
Kinase A

ABSTRACT N-Acetyl-d-glucosamine (GlcNAc) is a major component of bacterial cell wall murein and the lipopolysaccharide of the outer membrane. During growth, over 60% of the murein of the side wall is degraded, and the major products, GlcNAc-anhydro-N-acetylmuramyl peptides, are efficiently imported into the cytoplasm and cleaved to release GlcNAc, anhydro-N-acetylmuramic acid, murein tripeptide (l-Ala-d-Glu-meso-diaminopimelic acid), and d-alanine. Like murein tripeptide, GlcNAc is readily recycled, and this process was thought to involve phosphorylation, since GlcNAc-6-phosphate (GlcNAc-6-P) is efficiently used to synthesize murein or lipopolysaccharide or can be metabolized by glycolysis. Since the gene for GlcNAc kinase had not been identified, in this work we purified GlcNAc kinase (NagK) from Escherichia coli cell extracts and identified the gene by determining the N-terminal sequence of the purified kinase. A nagK deletion mutant lacked phosphorylated GlcNAc in its cytoplasm, and the cell extract of the mutant did not phosphorylate GlcNAc, indicating that NagK is the only GlcNAc kinase expressed in E. coli. Unexpectedly, GlcNAc did not accumulate in a nagK nagEBACD mutant, though both GlcNAc and GlcNAc-6-P accumulate in the nagEBACD mutant, suggesting the existence of an alternative pathway (presumably repressed by GlcNAc-6-P) that reutilizes GlcNAc without the involvement of NagK.

scholarly journals Optimization of expression, purification and secretion of functional recombinant human growth hormone in Escherichia coli using modified staphylococcal protein a signal peptide

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Garshasb Rigi ◽  
Amin Rostami ◽  
Habib Ghomi ◽  
Gholamreza Ahmadian ◽  
Vasiqe Sadat Mirbagheri ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Hormone ◽  
Signal Peptide ◽  
Extracellular Space ◽  
Culture Medium ◽  
Active Form ◽  
Protein A ◽  
Human Growth ◽  
E Coli ◽  
Sds Page

Abstract Background Human Growth Hormone (hGH) is a glycoprotein released from the pituitary gland. Due to the wide range of effects in humans, any disruption in hGH secretion could have serious consequences. This highlights the clinical importance of hGH production in the treatment of different diseases associated with a deficiency of this hormone. The production of recombinant mature hormone in suitable hosts and secretion of this therapeutic protein into the extracellular space can be considered as one of the best cost-effective approaches not only to obtain the active form of the protein but also endotoxin-free preparation. Since the natural growth hormone signal peptide is of eukaryotic origin and is not detectable by any of the Escherichia coli secretory systems, including Sec and Tat, and is therefore unable to secrete hGH in the prokaryotic systems, designing a new and efficient signal peptide is essential to direct hGh to the extracellular space. Results In this study, using a combination of the bioinformatics design and molecular genetics, the protein A signal peptide from Staphylococcus aureus was modified, redesigned and then fused to the mature hGH coding region. The recombinant hGH was then expressed in E. coli and successfully secreted to the medium through the Sec pathway. Secretion of the hGH into the medium was verified using SDS-PAGE and western blot analysis. Recombinant hGH was then expressed in E. coli and successfully secreted into cell culture medium via the Sec pathway. The secretion of hGH into the extracellular medium was confirmed by SDS-PAGE and Western blot analysis. Furthermore, the addition of glycine was shown to improve hGH secretion onto the culture medium. Equations for determining the optimal conditions were also determined. Functional hGH analysis using an ELISA-based method confirmed that the ratio of the active form of secreted hGH to the inactive form in the periplasm is higher than this ratio in the cytoplasm. Conclusions Since the native signal protein peptide of S. aureus protein A was not able to deliver hGH to the extracellular space, it was modified using bioinformatics tools and fused to the n-terminal region of hGh to show that the redesigned signal peptide was functional.

scholarly journals Escherichia coli Enteropatógena en Crías de Primate Aotus (Aotidae) con Diarrea en Cautiverio

2015 ◽  
Vol 26 (4) ◽  
pp. 657
Author(s):  
Nofre Sánchez P. ◽  
Isabel Arias B. ◽  
Hugo Gálvez C. ◽  
Victoria Carranza ◽  
Arnulfo Romaina R.
Keyword(s):  
Escherichia Coli ◽  
Enterobacter Aerogenes ◽  
Citrobacter Freundii ◽  
Proteus Vulgaris ◽  
E Coli

<p>La diarrea es el signo más frecuente de enfermedad gastrointestinal en crías de primates mantenidas en cautiverio. El estudio tuvo como objetivo aislar e identificar especies bacterianas presentes en crías de <em>Aotus </em>con diarrea que son criadas en cautiverio con fines experimentales. Se tomaron muestras de heces mediante hisopado rectal a 78 ejemplares de 1 a 7 meses de edad de <em>A. nancymae </em>(n=65) y <em>A. vociferans</em> (n=13) con diarrea y a 29 ejemplares de 1 mes de edad, aparentemente sanos de <em>A. nancymae </em>(n=21)<em> </em>y <em>A. vociferans</em> (n=8), durante el periodo de 2002 a 2005. En el grupo control se identificó principalmente <em>E. coli</em>, además de <em>Proteus vulgaris</em>, <em>P. mirabilis</em> y <em>Citrobacter freundii</em>. Resultado similar fue registrado en el grupo con diarrea, además de <em>Klebsiella oxitoca y Enterobacter aerogenes. </em>Los serotipos de <em>E. coli</em> enteropatógena (EPEC) identificados en el grupo con diarrea fueron siete: O158, O142, O86, O125, O126, O55 y O111. Los resultados indican que las crías con diarrea tienen bacterias que corresponden a la flora intestinal normal, siendo <em>E. coli </em>la de mayor frecuencia.</p>

scholarly journals THÀNH PHẦN HÓA HỌC VÀ HOẠT TÍNH KHÁNG VI SINH VẬT GÂY BỆNH CỦA TINH DẦU TỪ VỎ BƯỞI DA XANH (Citrus maxima (Burm.) Merr.)

2021 ◽  
Vol 130 (1C) ◽  
pp. 75-83
Author(s):  
Xuân Phong Huỳnh ◽  
Minh Châu Lưu ◽  
Thị Xuân Nghi Trần ◽  
Ngọc Thạnh Nguyễn ◽  
Hoàng Đăng Long Bùi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacillus Cereus ◽  
Aspergillus Flavus ◽  
Viet Nam ◽  
E Coli ◽  
Citrus Maxima

Bưởi là loài cây không chỉ có giá trị cao về mặt dinh dưỡng mà còn có giá trị cao về mặt kinh tế và được trồng phổ biến ở Việt Nam. Ngoài ra, tinh dầu bưởi chứa nhiều hợp chất có hoạt tính sinh học cao. Tinh dầu bưởi được chiết xuất bằng phương pháp chưng cất lôi cuốn hơi nước và thành phần hóa học được phân tích bằng phương pháp GC-MS. Thành phần chính của tinh dầu gồm limonene (91,19%), b-myrcene (2,92%), a-phellandrene (1,98%) và a-pinene (1,19%). Hoạt tính kháng vi sinh vật của tinh dầu được khảo sát với vi khuẩn Gram dương (Bacillus cereus, Staphylococcus aureus), Gram âm (Escherichia coli) và nấm mốc Aspergillus flavus ở nồng độ 5, 10, 25 và 50% bằng phương pháp khuếch tán giếng thạch. Tinh dầu có khả năng kháng B. cereus, S. aureus và E. coli với đường kính vòng kháng khuẩn lần lượt là 8,3–11,3, 10,3–18,7 và 9,0–11,7 mm và ức chế sự phát triển của A. flavus (18,9–65,0%).

scholarly journals Antiglycation Effects of Carnosine and Other Compounds on the Long-Term Survival of Escherichia coli

2010 ◽  
Vol 76 (24) ◽  
pp. 7925-7930 ◽  
Author(s):  
Evan D. Pepper ◽  
Michael J. Farrell ◽  
Gary Nord ◽  
Steven E. Finkel
Keyword(s):  
Escherichia Coli ◽  
Culture Medium ◽  
Term Survival ◽  
Long Term Survival ◽  
E Coli ◽  
Human Disorders ◽  
Domains Of Life ◽  
Carboxymethyl Lysine ◽  
Dose Dependent

ABSTRACT Glycation, or nonenzymatic glycosylation, is a chemical reaction between reactive carbonyl-containing compounds and biomolecules containing free amino groups. Carbonyl-containing compounds include reducing sugars such as glucose or fructose, carbohydrate-derived compounds such as methylglyoxal and glyoxal, and nonsugars such as polyunsaturated fatty acids. The latter group includes molecules such as proteins, DNA, and amino lipids. Glycation-induced damage to these biomolecules has been shown to be a contributing factor in human disorders such as Alzheimer's disease, atherosclerosis, and cataracts and in diabetic complications. Glycation also affects Escherichia coli under standard laboratory conditions, leading to a decline in bacterial population density and long-term survival. Here we have shown that as E. coli aged in batch culture, the amount of carboxymethyl lysine, an advanced glycation end product, accumulated over time and that this accumulation was affected by the addition of glucose to the culture medium. The addition of excess glucose or methylglyoxal to the culture medium resulted in a dose-dependent loss of cell viability. We have also demonstrated that glyoxylase enzyme GloA plays a role in cell survival during glycation stress. In addition, we have provided evidence that carnosine, folic acid, and aminoguanidine inhibit glycation in prokaryotes. These agents may also prove to be beneficial to eukaryotes since the chemical processes of glycation are similar in these two domains of life.

scholarly journals Expression of the Staphylococcus aureusUDP-N-Acetylmuramoyl- l-Alanyl-d-Glutamate:l-Lysine Ligase in Escherichia coli and Effects on Peptidoglycan Biosynthesis and Cell Growth

1999 ◽  
Vol 181 (19) ◽  
pp. 5909-5914 ◽  
Author(s):  
Dominique Mengin-Lecreulx ◽  
Tim Falla ◽  
Didier Blanot ◽  
Jean van Heijenoort ◽  
David J. Adams ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Morphological Changes ◽  
Diaminopimelic Acid ◽  
Side Chain ◽  
E Coli ◽  
Peptidoglycan Biosynthesis ◽  
Additional Information ◽  
The Third ◽  
Composition And Structure ◽  
Ca 50

ABSTRACT The monomer units in the Escherichia coli andStaphylococcus aureus cell wall peptidoglycans differ in the nature of the third amino acid in thel-alanyl-γ-d-glutamyl-X-d-alanyl-d-alanine side chain, where X is meso-diaminopimelic acid orl-lysine, respectively. The murE gene fromS. aureus encoding the UDP-N-acetylmuramoyl-l-alanyl-d-glutamate:l-lysine ligase was identified and cloned into plasmid vectors. Induction of its overexpression in E. coli rapidly results in abnormal morphological changes and subsequent cell lysis. A reduction of 28% in the peptidoglycan content was observed in induced cells, and analysis of the peptidoglycan composition and structure showed that ca. 50% of themeso-diaminopimelic acid residues were replaced byl-lysine. Lysine was detected in both monomer and dimer fragments, but the acceptor units from the latter contained exclusivelymeso-diaminopimelic acid, suggesting that no transpeptidation could occur between the ɛ-amino group ofl-lysine and the α-carboxyl group ofd-alanine. The overall cross-linking of the macromolecule was only slightly decreased. Detection and analysis ofmeso-diaminopimelic acid- andl-lysine-containing peptidoglycan precursors confirmed the presence of l-lysine in precursors containing amino acids added after the reaction catalyzed by the MurE ligase and provided additional information about the specificity of the enzymes involved in these latter processes.

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