scholarly journals A preliminary study on amphizoic amoebae with special reference to their preference for bacterial food

2010 ◽  
Vol 2 (1) ◽  
pp. 85-87
Author(s):  
Newton Paul ◽  
Tabrez Ahmad ◽  
A. K. Sharma
Keyword(s):  
Bacterial Species ◽  
Coli Strain ◽  
In Vitro Growth ◽  
Bacterial Strains ◽  
Poor Growth ◽  
E Coli ◽  
Nutrient Agar Medium ◽  
Preliminary Study ◽  
Acanthamoeba Culbertsoni

The present study was planned to screen the growth pattern of six different species of pathogenic and non pathogenic amphizoic amoebae viz. Naegleria fowleri, N. gruberi, Acanthamoeba culbertsoni, A. rhysodes, A. polyphaga and A. glebae using six different bacterial species like Escherichia coli (Strain E1 and E2 and E. coli lactose +ve), Proteus, Klebsiella and Pseudomonas as food in their in vitro growth on non-nutrient agar medium. It was observed that out of six amoebae used; the pathogenic N. fowleri and A. culbertsoni were feeding on E. coli (all the strains). Feeding these two species of bacteria, the growth of these two amoebae was luxuriant, but not so good while feeding other strains of bacteria though they fed, survived and formed cysts. The remaining four amoebae were found to feed and survive only on E. coli (all the strain) and formed cysts but showed very poor growth while feeding on other four bacterial strains. It was inferred that E. coli is the most suitable bacterial species for in vitro growth of amphizoic amoebae for various purposes. This also reiterates that there exists a complex inter-relationship between amoebae and bacteria in different habitats.

scholarly journals β-Lactamase inhibition profile of new amidine-substituted diazabicyclooctanes

2021 ◽  
Vol 17 ◽  
pp. 711-718
Author(s):  
Zafar Iqbal ◽  
Lijuan Zhai ◽  
Yuanyu Gao ◽  
Dong Tang ◽  
Xueqin Ma ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Second Generation ◽  
Bacterial Species ◽  
The Other ◽  
Inhibition Activity ◽  
Bacterial Strains ◽  
E Coli ◽  
Mic Value

The diazabicyclooctane (DBO) scaffold is the backbone of non-β-lactam-based second generation β-lactamase inhibitors. As part of our efforts, we have synthesized a series of DBO derivatives A1–23 containing amidine substituents at the C2 position of the bicyclic ring. These compounds, alone and in combination with meropenem, were tested against ten bacterial strains for their antibacterial activity in vitro. All compounds did not show antibacterial activity when tested alone (MIC >64 mg/L), however, they exhibited a moderate inhibition activity in the presence of meropenem by lowering its MIC values. The compound A12 proved most potent among the other counterparts against all bacterial species with MIC from <0.125 mg/L to 2 mg/L, and is comparable to avibactam against both E. coli strains with a MIC value of <0.125 mg/L.

scholarly journals MIC-Based Interspecies Prediction of the Antimicrobial Effects of Ciprofloxacin on Bacteria of Different Susceptibilities in an In Vitro Dynamic Model

1998 ◽  
Vol 42 (11) ◽  
pp. 2848-2852 ◽  
Author(s):  
Alexander A. Firsov ◽  
Sergey N. Vostrov ◽  
Alexander A. Shevchenko ◽  
Stephen H. Zinner ◽  
Giuseppe Cornaglia ◽  
...  
Keyword(s):  
Dynamic Model ◽  
Bacterial Species ◽  
Maximal Effect ◽  
Bacterial Strains ◽  
Time Curve ◽  
Antimicrobial Effects ◽  
E Coli ◽  
Kill Curve ◽  
Time Kill

ABSTRACT Multiple predictors of fluoroquinolone antimicrobial effects (AMEs) are not usually examined simultaneously in most studies. To compare the predictive potentials of the area under the concentration-time curve (AUC)-to-MIC ratio (AUC/MIC), the AUC above MIC (AUCeff), and the time above MIC (T eff), the kinetics of killing and regrowth of four bacterial strains exposed to monoexponentially decreasing concentrations of ciprofloxacin were studied in an in vitro dynamic model. The MICs of ciprofloxacin for clinical isolates ofStaphylococcus aureus, Escherichia coli11775 (I) and 204 (II), and Pseudomonas aeruginosa were 0.6, 0.013, 0.08, and 0.15 μg/ml, respectively. The simulated values of AUC were designed to provide similar 1,000-fold (S. aureus, E. coli I, and P. aeruginosa) or 2,000-fold (E. coli II) ranges of the AUC/MIC. In each case except for the highest AUC/MIC ratio, the observation periods included complete regrowth in the time-kill curve studies. The AME was expressed by its intensity,I E (the area between the control growth and time-kill and regrowth curves up to the point where the viable counts of regrowing bacteria are close to the maximum values observed without drug). For most AUC ranges the I E-AUC curves were fitted by an E max (maximal effect) model, whereas the effects observed at very high AUCs were greater than those predicted by the model. The AUCs that produced 50% of maximal AME were proportional to the MICs for the strains studied, but maximal AMEs (I E max ) and the extent of sigmoidicity (s) were not related to the MIC. BothT eff and log AUC/MIC correlated well withI E (r 2 = 0.98 in both cases) in a species-independent fashion. UnlikeT eff or log AUC/MIC, a specific relationship between I E and log AUCeff was inherent in each strain. Although each I E and log AUCeff plot was fitted by linear regression (r 2 = 0.97 to 0.99), these plots were not superimposed and therefore are bacterial species dependent. Thus, AUC/MIC and T eff were better predictors of ciprofloxacin’s AME than AUCeff. This study suggests that optimal predictors of the AME produced by a given quinolone (intraquinolone predictors) may be established by examining its AMEs against bacteria of different susceptibilities.T eff was shown previously also to be the best interquinolone predictor, but unlike AUC/MIC, it cannot be used to compare different quinolones. AUC/MIC might be the best predictor of the AME in comparisons of different quinolones.

scholarly journals In-Vitro Growth Inhibition of Bacterial Pathogens by Probiotics and a Synbiotic: Product Composition Matters

2020 ◽  
Vol 17 (9) ◽  
pp. 3332 ◽  
Author(s):  
Jacek Piatek ◽  
Hanna Krauss ◽  
Arleta Ciechelska-Rybarczyk ◽  
Malgorzata Bernatek ◽  
Paulina Wojtyla-Buciora ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Pathogenic Bacteria ◽  
Selection Process ◽  
In Vitro Growth ◽  
Bacterial Strains ◽  
Direct Inhibition ◽  
E Coli ◽  
Beneficial Effects ◽  
Different Types

A variety of activities potentially contribute to the beneficial effects of probiotic bacteria observed in humans. Among these is a direct inhibition of the growth of pathogenic bacteria in the gut. The present study characterizes head-to-head the in-vitro pathogen growth inhibition of clinically relevant infectious bacterial strains by different types of probiotics and a synbiotic. In-vitro growth inhibition of Escherichia (E.) coli EPEC, Shigella (Sh.) sonnei, Salmonella (S.) typhimurium, Klebsiella (K.) pneumoniae and Clostridioides (C.) difficile were determined. Investigated products were a yeast mono strain probiotic containing Saccharomyces (Sac.) boulardii, bacterial mono strain probiotics containing either Lactobacillus (L.) rhamnosus GG or L. reuteri DSM 17938, a multi strain probiotic containing three L. rhamnosus strains (E/N, Oxy, Pen), and a multi strain synbiotic containing nine different probiotic bacterial strains and the prebiotic fructooligosaccharides (FOS). Inhibition of pathogens was moderate by Sac. boulardii and L. rhamnosus GG, medium by L. reuteri DSM 17938 and the L. rhamnosus E/N, Oxy, Pen mixture and strong by the multi strain synbiotic. Head-to-head in-vitro pathogen growth inhibition experiments can be used to differentiate products from different categories containing probiotic microorganisms and can support the selection process of products for further clinical evaluation.

scholarly journals In Vitro, Controlling the Establishment of Xanthomonas Campestris with different Bacterial Bioagents

2016 ◽  
Vol 29 (1) ◽  
pp. 37-40
Author(s):  
Amna Ali ◽  
M Saleem Haider ◽  
Sobia Mushtaq ◽  
Ibatsam Khokhar ◽  
Irum Mukhtar ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Fruits And Vegetables ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Diffusion Technique

The antimicrobial agents of bacteria isolated from different rhizosphere of fruits and vegetables soil in Lahore. Of ten species, five were gram-negative (Escherichia coli, Pseudomonas fluorescence, Klebsiella pneumoniae, Salmonella typhii, Brachybacterium faecium); other five were gram positive and identified as Bacillus farraginis, Kurthia gibsonii, Aureobacterium liquefaciens, Curtobacterium albidum, Micrococcus lylae. The antagonistic potential of bacterial strains was assessed by the well diffusion technique and results indicating varying degree of biocontrol activity against pathogenic strain of X. campestris. Out of ten bacterial species, E. coli (gram negative) and C. albidum (gram positive) showed a high prevalence of resistance with reduction of 4.2cm and 4.1cm zone diameter respectively. The minimum inhibitory volume (MIV) to two bio-agents was determined for X. campestris from range 10-100 ?L. E. coli (volume required to inhibit < 20 ?L) and C. albidum (volume required to inhibit < 40 ?L) exhibited good activity against pathogen. These results provide information on the prevalence of resistant bacterial strains with the MIV of organisms and indicate the possibility of using these bacterial species as bio-agent against X. campestris.Bangladesh J Microbiol, Volume 29, Number 1, June 2012, pp 37-40

scholarly journals β-Lactamase inhibition profile of new amidine substituted diazabicyclooctanes

2020 ◽  
Author(s):  
zafar iqbal ◽  
Yuanyu Gao ◽  
Dong Tang ◽  
Xueqin Ma ◽  
Jinbo Ji ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Second Generation ◽  
Bacterial Species ◽  
The Other ◽  
Inhibition Activity ◽  
Bacterial Strains ◽  
E Coli ◽  
Mic Value

Diazabicyclooctane (DBO) scaffold is the backbone of non-β-lactam based second generation β-lactamase inhibitors. As part of our efforts we have synthesized a series of DBO derivatives A1-A23 containing amidine substituents at C2 position of the bicyclic ring. These compounds, alone and in combination with meropenem, were tested against ten bacterial strains for their antibacterial activity in vitro. All compounds didn’t show antibacterial activity when alone (MIC, >64 mg/L), however exhibited moderate inhibition activity in the presence of meropenem by lowering its MIC values. Compound A12 proved most potent among the other counterparts against all bacterial species with MIC from <0.125 mg/L – 2 mg/L, and is comparable to avibactam against both E. coli strains with MIC value of <0.125 mg/L.

Aetio-pathological studies of digestive and respiratory affections in cattle calves

2018 ◽  
Author(s):  
Sushma . ◽  
V. Nehra ◽  
J. Shunthwal and A.P. Rath
Keyword(s):  
Bacterial Species ◽  
Bacterial Strains ◽  
E Coli ◽  
Faecal Samples ◽  
Eimeria Spp ◽  
Heart Blood ◽  
Respiratory Systems ◽  
Klebsiella Spp ◽  
Number Of Bacteria

Aetio-pathological studies of digestive and respiratory affections was undertaken in cattle calves received for post mortem examination during a period of seven months (September, 2015 to March, 2016). Maximum age-wise mortality was noticed in age group of 1 to 3 months. Sex-wise mortality in cattle calves was more in females as compared to males. System-wise causes of death/mortality were highest due to combined involvement of both the digestive and respiratory systems. Pneumo-enteritis was the main affection noticed when there was combined involvement of both digestive and respiratory systems. Bacteriological studies of different samples collected from carcasses of cattle calves revealed that maximum bacterial species isolated was E. coli followed by Proteus spp., Klebsiella spp. and Staphyloccocus spp. Maximum number of bacteria species were isolated from intestine followed by lungs, heart blood and tracheal swab. The results of in-vitro drug sensitivity revealed that most of bacterial strains were sensitive to gentamycin and resistant to tetracycline. Examination of faecal samples of diarrhoeic/diseased and dead cattle calves revealed that Ascaris ova and Eimeria spp. was the major infection.

scholarly journals In Vitro Coliform Resistance to Bioactive Compounds in Urinary Infection, Assessed in a Lab Catheterization Model

2021 ◽  
Vol 11 (9) ◽  
pp. 4315
Author(s):  
Emanuel Vamanu ◽  
Laura Dorina Dinu ◽  
Cristina Mihaela Luntraru ◽  
Alexandru Suciu
Keyword(s):  
Urinary Tract ◽  
Bioactive Compounds ◽  
Urinary Tract Infections ◽  
Antimicrobial Effect ◽  
Biologically Active ◽  
Bacterial Strains ◽  
E Coli ◽  
Functional Product ◽  
Tract Infections

Bioactive compounds and phenolic compounds are viable alternatives to antibiotics in recurrent urinary tract infections. This study aimed to use a natural functional product, based on the bioactive compounds’ composition, to inhibit the uropathogenic strains of Escherichia coli. E. coli ATCC 25922 was used to characterize the IVCM (new in vitro catheterization model). As support for reducing bacterial proliferation, the cytotoxicity against a strain of Candida albicans was also determined (over 75% at 1 mg/mL). The results were correlated with the analysis of the distribution of biologically active compounds (trans-ferulic acid-268.44 ± 0.001 mg/100 g extract and an equal quantity of Trans-p-coumaric acid and rosmarinic acid). A pronounced inhibitory effect against the uropathogenic strain E. coli 317 (4 log copy no./mL after 72 h) was determined. The results showed a targeted response to the product for tested bacterial strains. The importance of research resulted from the easy and fast characterization of the functional product with antimicrobial effect against uropathogenic strains of E. coli. This study demonstrated that the proposed in vitro model was a valuable tool for assessing urinary tract infections with E. coli.

scholarly journals Design, Synthesis and Biological Evaluation of Novel Benzothiazole Based [1,2,4]Triazolo[4,3-c]quinazoline Derivatives

2020 ◽  
Vol 32 (3) ◽  
pp. 580-586
Author(s):  
Ranjit V. Gadhave ◽  
Bhanudas S. Kuchekar
Keyword(s):  
Biological Evaluation ◽  
Bacterial Strains ◽  
Active Compounds ◽  
Design Synthesis ◽  
Structural Modifications ◽  
E Coli ◽  
Chemical Structures ◽  
Ft Ir ◽  
Antioxidant Agent

A new series of N-(benzo[d]thiazol-2-yl)-[1,2,4]triazolo[4,3-c]quinazoline-5-carboxamide derivatives were synthesized by condensation of [1,2,4]triazolo[4,3-c]quinazoline-5-carboxylate derivatives with substituted benzothiazoles. The chemical structures of the synthesized compounds were confirmed by FT-IR, MS and 1H NMR spectra. Designed triazoloquinazoline derivatives were docked with oxido-reductase enzyme (PDB Code 4h1j) and DNA gyrase enzyme (PDB Code 3g75). Based on high binding affinity score, the best compound were selected for synthesis and subjected to in vitro antioxidant and antibacterial activity. Compounds 7a and 7d were found to be most active compounds as antioxidant agent among this series when compared with ascorbic acid. Compounds 7a, 7d and 7f were found to be most active compounds as an antibacterial agents among this series when compared with ciprofloxacin against bacterial strains such as S. aureus (ATCC 25923), E. coli (ATCC 25922) and P. aeruginosa (ATCC 27853). Study revealed that the most active compounds after structural modifications can be exploited as lead molecules for other pharmacological activities such as anti-inflammatory, anticancer and antidepressant activities.

scholarly journals Enhancing Terpene Yield from Sugars via Novel Routes to 1-Deoxy-d-Xylulose 5-Phosphate

2014 ◽  
Vol 81 (1) ◽  
pp. 130-138 ◽  
Author(s):  
James Kirby ◽  
Minobu Nishimoto ◽  
Ruthie W. N. Chow ◽  
Edward E. K. Baidoo ◽  
George Wang ◽  
...  
Keyword(s):  
Bacterial Species ◽  
Xylose Reductase ◽  
Pentose Phosphate ◽  
Terpene Biosynthesis ◽  
Content Type ◽  
E Coli ◽  
Pathway Expression ◽  
Terpene Synthesis ◽  
Selection For

ABSTRACTTerpene synthesis in the majority of bacterial species, together with plant plastids, takes place via the 1-deoxy-d-xylulose 5-phosphate (DXP) pathway. The first step of this pathway involves the condensation of pyruvate and glyceraldehyde 3-phosphate by DXP synthase (Dxs), with one-sixth of the carbon lost as CO2. A hypothetical novel route from a pentose phosphate to DXP (nDXP) could enable a more direct pathway from C5sugars to terpenes and also circumvent regulatory mechanisms that control Dxs, but there is no enzyme known that can convert a sugar into its 1-deoxy equivalent. Employing a selection for complementation of adxsdeletion inEscherichia coligrown on xylose as the sole carbon source, we uncovered two candidate nDXP genes. Complementation was achieved either via overexpression of the wild-typeE. coliyajOgene, annotated as a putative xylose reductase, or via various mutations in the nativeribBgene.In vitroanalysis performed with purified YajO and mutant RibB proteins revealed that DXP was synthesized in both cases from ribulose 5-phosphate (Ru5P). We demonstrate the utility of these genes for microbial terpene biosynthesis by engineering the DXP pathway inE. colifor production of the sesquiterpene bisabolene, a candidate biodiesel. To further improve flux into the pathway from Ru5P, nDXP enzymes were expressed as fusions to DXP reductase (Dxr), the second enzyme in the DXP pathway. Expression of a Dxr-RibB(G108S) fusion improved bisabolene titers more than 4-fold and alleviated accumulation of intracellular DXP.

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