Plasma catecholamines during E. coli bacteremia in conscious rats

1988 ◽  
Vol 254 (3) ◽  
pp. R470-R477 ◽  
Author(s):  
S. B. Jones ◽  
M. V. Westfall ◽  
M. M. Sayeed

Fasted, conscious male rats, prepared with arterial and venous cannulas, were given doses (10(10)-10(11) organisms/kg) of live Escherichia coli bacteria. Heart rate and blood pressure were recorded, and arterial plasma samples were taken preinjection and at 30, 180, and 360 min after bacterial administration. Plasma was analyzed for lactate, glucose, norepinephrine (NE), and epinephrine (E). Rats given E. coli were normotensive but with significant tachycardia (P less than 0.05 vs. saline). Plasma NE and E levels increased severalfold during bacteremia (P less than 0.05 for all comparisons). Rats were euglycemic but had a sixfold increase in lactate 6 h (P less than 0.05) after E. coli treatment. Additional rats were subjected to the same protocol but had been made tolerant to bacterial endotoxin by multiple injections over the course of several days. Endotoxin-tolerant rats were also tolerant to live E. coli administration (P less than 0.05, 24 h survival) and had significantly reduced levels of E and NE at 6 h compared with nontolerant bacteremic rats (P less than 0.05). Increases in heart rate and plasma lactate were not significant in endotoxin-tolerant rats. These results suggest profound sympathetic activation during acute bacteremia with attenuated activation in endotoxin-tolerant rats. Tolerance appears to reduce the afferent stimuli that are presumably activated during the course of bacteremia.

Author(s):  
YOJANA Y. PATIL ◽  
VAISHNVI B. SUTAR ◽  
ARPITA P. TIWARI

Objective: The present study was aimed at the biological synthesis of magnetic iron nanoparticles by using the plant extract of Tridax procumbens and also to study their antimicrobial property against gram-negative bacteria (Escherichia coli). Methods: The synthesis of magnetic iron nanoparticles was carried out by the co-precipitation method using biological methods like plant extract as reducing agent and capping agents are biocompatible and non-hazardous. These nanoparticles were characterized by UV-Visible spectroscopy, XRD (X-Ray Diffraction), and SEM (Scanning Electron Microscope). As well as antibacterial activity of the nanoparticles was carried out by agar well diffusion method and Most Probable Number (MPN) method against gram-negative E. coli (Escherichia coli) bacteria. Results: The average crystallite size of Magnetic Nanoparticles (MNPs) was found to be 72 nm by X-ray diffraction. The optical absorption band at wavelengths of 240 nm and 402 nm was obtained from the UV Visible spectrum. Spherical shape morphology was observed in SEM studies. The antibacterial assay clearly expressed that E. coli showed a maximum zone of inhibition (15±0.15 mm) at 2 mg/ml and 1 mg/ml concentration was found for Magnetic Nanoparticles. In the Most Probable Number (MPN) test it is seen that the bacterial count is reduced after adding synthesized NPs into the water sample. Conclusion: The results of the present study conclude that the Magnetic Nanoparticles synthesized using Tridax procumbens leaf extracts is found to be stable and show good antibacterial activity against gram-negative (Escherichia coli) bacteria.


2010 ◽  
Vol 192 (7) ◽  
pp. 1796-1800 ◽  
Author(s):  
Yevgeniy Kalinin ◽  
Silke Neumann ◽  
Victor Sourjik ◽  
Mingming Wu

ABSTRACT Escherichia coli chemotaxis has long served as a simple model of environmental signal processing, and bacterial responses to single chemical gradients are relatively well understood. Less is known about the chemotactic behavior of E. coli in multiple chemical gradients. In their native environment, cells are often exposed to multiple chemical stimuli. Using a recently developed microfluidic chemotaxis device, we exposed E. coli cells to two opposing but equally potent gradients of major attractants, methyl-aspartate and serine. The responses of E. coli cells demonstrated that chemotactic decisions depended on the ratio of the respective receptor number of Tar/Tsr. In addition, the ratio of Tar to Tsr was found to vary with cells’ growth conditions, whereby it depended on the culture density but not on the growth duration. These results provide biological insights into the decision-making processes of chemotactic bacteria that are subjected to multiple chemical stimuli and demonstrate the importance of the cellular microenvironment in determining phenotypic behavior.


2015 ◽  
Vol 34 ◽  
pp. 61-66
Author(s):  
Kamarulazizi Ibrahim ◽  
Mohammad Hafiz Khalid ◽  
Mohamed Hassan Eisa ◽  
Mohd Nazalan Najimudin ◽  
Mohammad A. Al Rajhi ◽  
...  

In this work, a comparative study using atomic force microscopy (AFM) and field emission–scanning electron microscopy (FESEM) has been carried out to assess the morphology of single cellEscherichia colibacteria (E-coli).E-colibacteria are a major concern for public health. Attention was focused on the certain strains ofE-colibacteria, because some strains can be toxic and cause food poisoning. TheE-colibacteria have attracted much research interest because this bacterium is easily to get, cheap and rapid reproductively. Imaging ofE-colirecently, was improved by using high resolution microscopy. Current techniques for detection such as, AFM and FESEM has attracted great interest and emerging as a potentially powerful whole-organism fingerprinting tool for the rapid identification of bacteria. The obtained results of AFM and FESEM techniques have been compared to show the image quality of single cellE-coli.


1995 ◽  
Vol 88 (4) ◽  
pp. 439-446 ◽  
Author(s):  
Kjell Larsson ◽  
Per Carlens ◽  
Sture Bevegård ◽  
Paul Hjemdahl

1. Bronchoconstriction does not seem to be a stimulus for sympathoadrenal activation, as judged by venous plasma concentrations of noradrenaline, adrenaline or neuropeptide Y-like immunoreactivity. However, venous measurements have methodological drawbacks. In the present study arterial and mixed venous (pulmonary arterial) levels of these variables were determined before and after histamine-induced bronchoconstriction in non-medicated asthmatic subjects. In addition, noradrenaline kinetics in plasma (isotope dilution) and the pulmonary overflows of noradrenaline and neuropeptide Y-like immunoreactivity were determined. 2. Histamine inhalation induced bronchoconstriction; forced expiratory volume in 1 s decreased by 38.7% ± 4.1% (SE) and arterial Po2 by 3.0 ± 0.9 kPa. This acute bronchoconstriction induced significant elevations of arterial and mixed venous plasma noradrenaline from ≤1.18 nmol/l to ≥1.40 nmol/l. The clearance of NA from plasma increased marginally. Thus, the arterial plasma NA response was due to increased spillover of noradrenaline to plasma (from 1.80 ± 0.18 to 2.52 ± 0.36 mmol min−1/m2 at maximal bronchoconstriction, with a subsequent further increase). There were no elevations of adrenaline or neuropeptide Y-like immunoreactivity in arterial plasma. 3. No sympathetic activation could be demonstrated in the lungs (pulmonary noradrenaline or neuropeptide Y-like immunoreactivity overflow), and no alterations in pulmonary vascular resistance or cardiac output were observed. Neither arterial nor mixed venous plasma concentrations of adrenaline were influenced by bronchoconstriction. 4. Acute bronchoconstriction thus leads to peripheral sympathetic activation (possibly due to the increased work of breathing) which does not involve the lungs. Adrenaline is not secreted in response to induced bronchoconstriction, and thus is of no functional importance as a counter-regulatory hormone in this situation.


PHARMACON ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 834
Author(s):  
Eunike Pelealu ◽  
Defny S. Wewengkang ◽  
Surya Sumantri Abdullah

ABSTRACTSponges are one of the biota components that make up coral reefs which are quite widely distributed. The metabolite content in the sponge can ward off and inhibit the pathogenic bacteria that interfere with it. This study aims to determine the activity of inhibiting bacterial growth from the extract and fraction of Leucetta chagosensis sponge against the growth of Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria. The samples were extracted using the maceration method with 95% ethanol solvent and then fractionated using 3 solvents with different polarity levels, namely methanol, n-hexane and chloroform. Activity test using the disk diffusion agar method of Kirby and Bauer. Only the MeOH fraction was able to inhibit the growth of E. coli bacteria with an average inhibition zone of 6.88 mm. Whereas for S.aureus bacteria extracts and all fractions showed activity to inhibit bacterial growth with an average inhibition zone of EtOH (6.61 mm), CHCI3 (6.68 mm), n-hexane (7.83 mm) and MeOH (8.00 mm), respectively. All activities that are shown are categorized as weak (weak).Keywords: Antibacterial, Leucetta chagosensis, Staphylococcus aureus, Escherichia coli ABSTRAKSpons merupakan salah satu komponen biota penyusun terumbu karang yang penyebarannya cukup luas. Kandungan metabolit yang ada di dalam spons dapat menangkal dan menghambat bakteri patogen pengganggunya.  Penelitian ini bertujuan untuk melihat aktivitas menghambat pertumbuhan bakteri dari ekstrak dan fraksi spons Leucetta chagosensis. terhadap pertumbuhan bakteri Gram positif Staphylococcus aureus dan Gram negatif Escherichia coli. Sampel di ekstraksi menggunakan metode maserasi dengan pelarut etanol 95% lalu di fraksinasi dengan menggunakan 3 pelarut dengan tingkat kepolaran yang berbeda yaitu metanol, n-heksan dan kloroform. Uji aktivitas menggunakan metode disk diffusion agar Kirby dan Bauer.  Hanya fraksi MeOH yang mampu menghambat pertumbuhan bakteri E.coli dengan zona hambat rata-rata 6,88 mm. Sedangkan terhadap bakteri S.aureus ekstrak dan semua fraksi menunjukan aktifitas menghambat pertumbuhan bakteri dengan rata-rata zona hambat masing-masing EtOH (6,61 mm), CHCl3 (6,68 mm), n-Heksan (7,83 mm), dan MeOH (8,00 mm). Semua aktivitas yang ditunjukan dikategorikan lemah (weak).Kata kunci : Antibakteri, Leucetta chagosensis, Staphylococcus aureus,  Escherichia coli


2021 ◽  
Vol 11 (6) ◽  
pp. 61-67
Author(s):  
Hertina Silaban

Bacterial infection of Escherichia coli (E. coli) as the cause of gastrointestinal disorders in humans has increased their prevalence. Treatment using natural ingredients can be a choice of therapy because of the minimal side effects. One of the rare plants believed by the community as an antibacterial is stinking vin’e known as the ‘leaf fart’. The purpose of this research is for knowing the activity of the ethanol extract of Paederia foetida L can affect the growth of E.coli. The serial diffusion disc method is being used as the antibacterial activity test. The concentration  of this extract are 10%, 20%, 40%, 80%, 100% with positive control (ciprofloxacin) and negative control (aqua dest). The inhibition zone diameter characterized the effect of Extract on bacterial growth were 6.16 mm of the concentration 10%, 6.667 mm of the concentration 20%, 7.10 mm of the concentration 40 %, 7.78 mm of the concentration 80%, and 10.03 mm of the concentration 100%. As for the negative control has no effect. The study stated that the higher concentration of antibacterial agent used, the greater the inhibition zone formed. Based on the result of the analysis of the data by using the One-Way ANOVA Test showed a probability value (p) = 0.000 or value (p) < 0.05, that H0 is rejected and H1 is accepted. The conclusion is that the Extract of stinking vin’e has an antibacterial effect on the growth of E.coli. Keywords: Antibacterial, E.coli, Extract of  Sembukan leaf


2021 ◽  
Vol 8 (2) ◽  
pp. 81-85
Author(s):  
Jean Poll Alva-Araujo ◽  
María de los Ángeles García-Hernández ◽  
Asunción Guadalupe Morales Mendoza ◽  
Refugio Rodríguez-Vázquez

The heterogeneous photocatalysis consists of the generation of reactive oxygen species (•OH, •-O2) from a catalyst, UV light, and oxygen; these reactive species can degrade contaminants and eliminate microorganisms. The purpose of this research was to evaluate a heterogeneous photocatalysis system and an UV light disinfection system for the elimination of total coliforms and Escherichia coli bacteria present in rainwater stored in five cisterns in Mexico City. The elimination of total coliforms (MPN/100 mL) and Escherichia coli (CFU/100 mL) were evaluated both in the rainwater treated with TiO2/UV and UV (in time periods of 30 and 60 minutes), according to the treatments established in the statistical model 22. The results show that although complete elimination of initial total coliforms (9.3 x 104 MPN/100 mL) and E. coli bacterium (1.5 x 103 CFU/mL) was achieved in one of the samples of rainwater using only UV light at 254 nm for 30 minutes, the use of 8 films coated with Degussa P-25 titanium dioxide, UV light at 254 nm and 1.5 vvm air in a reactor, achieves a total pathogen removal in a shorter time of 15 minutes. Thus, we anticipate that the combined treatment could be an alternative disinfection process for rainwater stored in cisterns, reducing costs and making the treatment viable for a larger-scale application.


2018 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Abrianto A. O. Rompis ◽  
Fitje Losung ◽  
Deiske A. Sumilat ◽  
Agung B. Windarto ◽  
Stenly Wullur ◽  
...  

The sponge is one of the sea organisms that has a prospect as a source of natural compounds including peptides, steroids, asetogenin, terpenoids, alkaloids, cyclic halide and nitrogen. This research was directed to obtain several species of sponges from the waters of Tasik Ria as well as testing the antibacterial activity of extracts from some of the sponge against the bacteria Escherichia coli and Staphylococcus aureus. From the identification, seven species of sponges were found, which consists of: Amphimedon sp., Axinosa sp., Aaptos sp., Theonella sp., Cribochalina sp., Hyrtios sp., and Lendenfeldia sp. The tests of antibacterial activity of the extracts from these sponges against test bacteria E. coli and S. aureus showed some positive results. Extract from Axinosa sp. sponge(16 mm) showed the strongest antibacterial activity on Escherichia coli bacteria. Followed by Hyrtios sp. extract (13.5 mm), Aaptos sp. extract (13 mm), Lendenfeldia sp. extract (13 mm) and Cribochalinai sp. extract(10.5 mm). While the the tests on Staphylococcus aureus bacteria showed that the strongest antibacterial activity was found from Axinosa sp. sponge extract (16.5 mm), followed by the extract from Aaptos sp. (15 mm), Lendenfeldia sp. extract (14.5 mm), Hyrtios sp. extract(13.5 mm) and Cribochalina sp. extract (11 mm).Keywords: Sponge, antibacterial, Escherichia coli, Staphylococcus aureus ABSTRAK Spons merupakan salah satu biota laut yang sangat prospektif sebagai sumber senyawa bahan-bahan alami antara lain peptide, terpenoid, steroid, asetogenin, alkaloid, halide siklik dan senyawa nitrogen. Penelitian ini diarahkan untuk mendapatkan beberapa spesies spons dari perairan Tasik Ria serta menguji aktivitas antibakteri dari beberapa ekstrak spons terhadap bakteri Escherichia coli dan bakteri Staphylococcus aureus. Hasil identifikasi spons ditemukan sebanyak tujuh spesies yang terdiri dari: Amphimedon sp., Axinosa sp., Aaptos sp., Theonella sp., Hyrtios sp., Cribochalina sp. dan Lendenfeldia sp.. Aktivitas antibakteri dari beberapa ekstrak spons terhadap bakteri uji E. coli dan S. aureus terdapat diameter zona hambat bervariasi yaitu bakteri Escherichia coli menunjukkan aktivitas antibakteri ekstrak spons terkuat pada spons Axinosa sp (16 mm), disusul ekstrak spons Hyrtios sp. (13,5 mm), ekstrak spons Aaptos sp. (13 mm), ekstrak spons Lendenfeldia sp. (13 mm) dan ekstrak spons Cribochalinai sp. (10,5 mm).  Sedangkan pada bakteri Staphylococcus aureus menunjukkan aktivitas antibakteri ekstrak spons terkuat yaitu:  ekstrak spons Axinosa sp. (16,5 mm), disusul ekstrak spons Aaptos sp. (15 mm), ekstrak spons Lendenfeldia sp. (14,5 mm), ekstrak spons Hyrtios sp. (13,5 mm) dan ekstrak spons Cribochalina sp.(11mm).Kata Kunci : Spons, Antibakteri, Escherichia coli, Staphylococcus aureus


2018 ◽  
Vol 12 (08) ◽  
pp. 608-615 ◽  
Author(s):  
Belayneh Regasa Dadi ◽  
Tamrat Abebe ◽  
Lixin Zhang ◽  
Adane Mihret ◽  
Workeabeba Abebe ◽  
...  

Introduction: Urinary tract infection is a major cause of morbidity and mortality worldwide. Uropathogenic Escherichia coli bacteria are the most common cause of urinary tract infections. Drug resistant Escherichia coli is results in high levels of treatment failure and can be a significant threat to survival of patients. Methodology: Escherichia coli bacteria were isolated using culture and conventional biochemical tests. Antimicrobial susceptibility testing and plasmid profile were performed using the Kirby Bauer disc diffusion method and plasmid analysis. Data was processed with SPSS version 16.0 and Epi-info version 3.4.1 software. Results: The highest proportion of Escherichia coli isolates was resistant to (86.5%) to ampicillin, followed by ceftazidime (84%), ceftriaxone (80.5%), tetracycline (80%), trimethoprim-sulfamethoxazole (68.5%) and cefotaxime (66%). Escherichia coli isolates were most susceptible to meropenem (100%), imipenem (100%), amikacin (97.5%), nitrofurantoin (95%), ciprofloxacin (85.5%), norfloxacin (85%), chloramphenicol (83.5%), gentamycin (80%) and nalidixic acid (79%). Multidrug resistance (MDR) was observed in most (96.5%) E. coli isolates. Plasmid analysis revealed the presence of plasmid(s) in 165 (82.5%) of the E. coli isolates many of which had a plasmid size of 23 kb. Conclusions: The overall incidence of antibiotic resistance (including MDR) among E. coli in this study was high to commonly used antibiotics, but no drug resistance to meropenem and imipenem was observed. Periodic monitoring of the drug resistance pattern is essential for better management of urinary tract infections, which has direct impact on the outcome of the patient.


Author(s):  
SUNARTI M.BIOMED ◽  
DEBORA PANINSARI

Objective: The objective of this study was to discover of the ethanolic extract of Rhinacanthus nasutus (L) Kurz in inhibiting Escherichia coli bacteria using an in vitro method. Methods: This is an experimental study using a laboratory test with Kirby-Bauer or paper disc method by observing and measuring the inhibition zone of the ethanolic extract of R. nasutus against E. coli bacteria with extract concentrations of 15%, 30%, and 60% consisting of control groups and treatment group. The positive control group used chloramphenicol antibiotics and negative control groups used Aquadest. E. coli was incubated at 37°C for 24 h. Then, the plates were incubated for 24 h at 37°C and the diameter of the inhibition zone was observed until the 3rd day with three repetitions. Results: The results of the study showed that the mean inhibition zone of E. coli bacteria was 10.93 mm, 12.09 mm, and 18.90 mm. The results of the Shapiro–Wilk test were p=0.199. The results of the one-way analysis of variance test were p<0.05 and that of the post hoc test indicated a significant value of p<0.05. Based on the results of the research, there were significant differences in the inhibition zone between the control group and the treatment group at a concentration of 15%, 30%, and 60%. Conclusion: R. nasutus extract was effective to inhibit the growth of E. coli bacteria at concentrations of 15%, 30%, and 60%, so R. nasutus is effective as an antimicrobial.


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