Toxicity of the First Ten MEIC Chemicals to Bacteria

1993 ◽  
Vol 21 (2) ◽  
pp. 151-155
Author(s):  
Gustaw Kerszman
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Linear Regression ◽  
Minimal Inhibitory Concentration ◽  
Blood Concentration ◽  
Inhibitory Concentration ◽  
Human Lymphocytes ◽  
Bacterial Species ◽  
E Coli ◽  
Mild Toxicity

The toxicity of the first ten MEIC chemicals to Escherichia coli and Bacillus subtilis was examined. Nine of the chemicals were toxic to the bacteria, with the minimal inhibitory concentration (MIC) ranging from 10-3 to 4.4M. The sensitivities of both organisms were similar, but the effect on E. coli was often bactericidal, while it was bacteriostatic for B. subtilis. Digoxin was not detectably toxic to either bacterial species. Amitriptyline and FeSO4 were relatively less toxic to the bacteria than to human cells. For seven chemicals, a highly significant linear regression was established between log MIC in bacteria and log of blood concentration, giving lethal and moderate/mild toxicity in humans, as well as with toxicity to human lymphocytes.

scholarly journals Antithetic population response to antibiotics in a polybacterial community

2020 ◽  
Vol 6 (10) ◽  
pp. eaaz5108 ◽  
Author(s):  
L. Galera-Laporta ◽  
J. Garcia-Ojalvo
Keyword(s):  
Escherichia Coli ◽  
Mathematical Model ◽  
Bacillus Subtilis ◽  
Bacterial Species ◽  
Single Species ◽  
Population Response ◽  
E Coli ◽  
Collective Response ◽  
Lactam Antibiotic ◽  
Mixed Community

Much is known about the effects of antibiotics on isolated bacterial species, but their influence on polybacterial communities is less understood. Here, we study the joint response of a mixed community of nonresistant Bacillus subtilis and Escherichia coli bacteria to moderate concentrations of the β-lactam antibiotic ampicillin. We show that when the two organisms coexist, their population response to the antibiotic is opposite to that in isolation: Whereas in monoculture B. subtilis is tolerant and E. coli is sensitive to ampicillin, in coculture it is E. coli who can proliferate in the presence of the antibiotic, while B. subtilis cannot. This antithetic behavior is predicted by a mathematical model constrained only by the responses of the two species in isolation. Our results thus show that the collective response of mixed bacterial ecosystems to antibiotics can run counter to what single-species potency studies tell us about their efficacy.

scholarly journals Human isolates of apramycin-resistant Escherichia coli which contain the genes for the AAC(3)IV enzyme

1993 ◽  
Vol 110 (2) ◽  
pp. 253-259 ◽  
Author(s):  
J. E. B. Hunter ◽  
C. A. Hart ◽  
J. C. Shelley ◽  
J. R. Walton ◽  
M. Bennett
Keyword(s):  
Escherichia Coli ◽  
Minimal Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Aminoglycoside Antibiotic ◽  
Dna Probe ◽  
Conjugative Plasmid ◽  
E Coli ◽  
High Level ◽  
Level Resistance

SUMMARYGentamicin-resistant Escherichia coli isolated at different periods from patients in two hospitals were tested for resistance to the aminoglycoside antibiotic apramycin. Twenty-four of 93 (26%) gentamicin-resistant isolates collected from the Royal Liverpool Hospital between 1981 and 1990 were resistant to apramycin. Thirteen isolates were highly resistant to apramycin (minimal inhibitory concentration (MIC) ≥ 1024 μg/ml). were also resistant to gentamicin, netilmicin and tobramycin, and hybridized with a DNA probe derived from the aminoglycoside acetyltransferase (3)IV (AAC(3)IV) gene. The proportion of gentamicinresistant isolates which had high level resistance to apramycin increased from 7% in 1981–5 to 24% in 1986–90.Twelve gentamicin-resistant E. coli from Guy's and St Thomas's Hospital isolated between 1977 and 1980 were also tested for resistance to apramycin. For five of these isolates the MICs of apramycin was 32–256 μg/ml. None was shown to have a conjugative plasmid carrying resistance to apramycin and only one hybridized with the DNA probe for the AAC(3)IV enzyme.

Synthesis and Structures of Halo-Substituted Aroylhydrazones with Antimicrobial Activity

2012 ◽  
Vol 65 (4) ◽  
pp. 343 ◽  
Author(s):  
Mei Zhang ◽  
Dong-Mei Xian ◽  
Hai-Hua Li ◽  
Ji-Cai Zhang ◽  
Zhong-Lu You
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Inhibitory Concentration ◽  
Antimicrobial Activities ◽  
X Ray Diffraction ◽  
X Ray ◽  
E Coli ◽  
Diphenyl Tetrazolium Bromide

A series of new halo-substituted aroylhydrazones have been prepared and structurally characterized by elemental analysis, 1H NMR, 13C NMR, and IR spectra, and single crystal X-ray diffraction. The compounds were evaluated for their antibacterial (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas fluorescence) and antifungal (Candida albicans and Aspergillus niger) activities by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) method. Among the tested compounds, N′-(2-chloro-5-nitrobenzylidene)-2-fluorobenzohydrazide showed the most effective antimicrobial activity with minimum inhibitory concentration values of 0.82, 2.5, 1.7, 15.2, and 37.5 μg mL–1 against B. subtilis, S. aureus, E. coli, P. fluorescence, and C. albicans, respectively. The biological assay indicated that the presence of the electron-withdrawing groups in the aroylhydrazones improved their antimicrobial activities.

Hypobaric bacteriology: growth, cytoplasmic membrane polarization and total cellular fatty acids in Escherichia coli and Bacillus subtilis

2005 ◽  
Vol 4 (3-4) ◽  
pp. 187-193 ◽  
Author(s):  
N.J. Pokorny ◽  
J.I. Boulter-Bitzer ◽  
M.M. Hart ◽  
L. Storey ◽  
H. Lee ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Bacillus Subtilis ◽  
Membrane Fluidity ◽  
Cytoplasmic Membrane ◽  
Unsaturated Fatty Acids ◽  
Bacterial Species ◽  
E Coli ◽  
Membrane Polarization ◽  
Cellular Fatty Acids

Escherichia coli JM109 (Gram-negative) and Bacillus subtilis (Gram-positive) were grown under hypobaric conditions for 19 days at 25 °C to study the effects of 33 and 67 kPa low pressures on selected physiological responses; growth, cytoplasmic membrane polarization (measure of cytoplasmic membrane fluidity) and total cellular fatty acids. In the first experiment, cytoplasmic membrane polarization in B. subtilis increased under both hypobaric conditions, indicating the membrane became more rigid or less fluid. This experiment was repeated and the effect of the hypobaric conditions was not evident as in the first experiment with B. subtilis. In addition, total cellular fatty acids analysis for B. subtilis showed that hypobaric conditions did not alter the ratio of saturated to unsaturated fatty acids. The cytoplasmic membrane remained in the same fluid state in hypobaric grown E. coli cell cultures as in the 101 kPa ambient control cells in both experiments. However, the saturated to unsaturated ratios were altered in E. coli under hypobaric conditions. It is important to note the ratios for E. coli were less than 1, while the ratios for Bacillus were in the 28–50 range. Growth of both species was also measured by colony forming units at the termination of the 19 day experiment. Both bacterial species were capable of growth under hypobaric conditions and no distinct trend emerged as to the effect of hypobaric pressure on bacterial growth and cytoplasmic membrane fluidity.

Effect of hydrogen peroxide on antibacterial activities of Canadian honeys

2006 ◽  
Vol 52 (12) ◽  
pp. 1228-1237 ◽  
Author(s):  
Katrina Brudzynski
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Antibacterial Activity ◽  
Bacillus Subtilis ◽  
Specific Activity ◽  
Bacterial Species ◽  
Antibacterial Activities ◽  
Therapeutic Effects ◽  
E Coli ◽  
The Impact

Honey is recognized as an efficacious topical antimicrobial agent in the treatment of burns and wounds. The antimicrobial activity in some honeys depends on the endogenous hydrogen peroxide content. This study was aimed to determine whether honey's hydrogen peroxide level could serve as a honey-specific, activity-associated biomarker that would allow predicting and assessing the therapeutic effects of honey. Using a broth microdilution assay, I analyzed antibacterial activities of 42 Canadian honeys against two bacterial strains: Escherichia coli (ATCC 14948) and Bacillus subtilis (ATCC 6633). The MIC90 and MIC50 were established from the dose-response relationship between antibacterial activities and honey concentrations. The impact of H2O2 on antibacterial activity was determined (i) by measuring the levels of H2O2 before and after its removal by catalase and (ii) by correlating the results with levels of antibacterial activities. Canadian honeys demonstrated moderate to high antibacterial activity against both bacterial species. Both MIC90 and MIC50 revealed that the honeys exhibited a selective growth inhibitory activity against E. coli, and this activity was strongly influenced by endogenous H2O2 concentrations. Bacillus subtilis activity was marginally significantly correlated with H2O2 content. The removal of H2O2 by catalase reduced the honeys' antibacterial activity, but the enzyme was unable to completely decompose endogenous H2O2. The 25%-30% H2O2 "leftover" was significantly correlated with the honeys' residual antibacterial activity against E. coli. These data indicate that all Canadian honeys exhibited antibacterial activity, with higher selectivity against E. coli than B. subtilis, and that these antibacterial activities were correlated with hydrogen peroxide production in honeys. Hydrogen peroxide levels in honey, therefore, is a strong predictor of the honey's antibacterial activity.Key words: honey, antibacterial activity, hydrogen peroxide, catalase, Escherichia coli, Bacillus subtilis.

scholarly journals Antibacterial and antioxidant potentials of leave extracts of Helianthus annuus

10.5219/1228 ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 1026-1033 ◽  
Author(s):  
Oghenerobor Akpor ◽  
Tomilola Olaolu ◽  
Damilare Rotimi
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Ethyl Acetate ◽  
Helianthus Annuus ◽  
Bacterial Species ◽  
Radical Scavenging ◽  
Dpph Radical ◽  
E Coli ◽  
Dpph Radical Scavenging ◽  
Radical Scavenging Assay

Helianthus annuus has been widely used for its medicinal and nutritional properties. This study was aimed at assessing the ethyl acetate, n-hexane and methanol extracts of Helianthus annuus for antibacterial and antioxidant potentials.  The phytochemical screening, total phenols, DPPH radical scavenging assay and nitric oxide radical scavenging activity were carried out following standard procedures. Preliminary screening of the antibacterial activities of the extracts was carried out on five bacterial species (Bacillus subtilis, E. coli, Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella pneumoniae), using the agar-diffusion method. Growth rate studies in presence of the extract was investigated on two bacterial species (Bacillus subtilis and E. coli). The methanol extract was observed to inhibit the growth of the five bacterial species while ethyl acetate and N-hexane extracts showed inhibition against Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. Extended lag periods of 5 – 6 h were observed when the Bacillus subtilis and Escherichia coli were grown in broth medium that contained the respective extracts. In broth medium with mixture of extract and ascorbic acid, there was no observed growth of the Bacillus subtilis and Escherichia coli throughout the 7 h incubation period. The total phenolics content of the extracts revealed concentrations of 6.66 ±0.45, 5.58 ±0.11 and 6.06±0.41 mg TAE.g-1) for the methanol, N-hexane and ethyl acetate extracts respectively. The DPPH radical scavenging assay results displayed gradual increase in percentage inhibition from the lowest to the highest concentration across all the standard groups, a similar trend was observed with the extracts, the ethyl acetate extract showed highest percentage inhibition amongst the other extracts. All the extracts showed high reducing power ability. The nitric oxide scavenging ability of the extracts showed constant increase with increase in concentration. Helianthus annus, it could be a good source of antimicrobial and antioxidant especially in a world where resistance to antibiotic has increasingly become a global concern.

scholarly journals Nonnative Proteins Induce Expression of the Bacillus subtilis CIRCE Regulon

1998 ◽  
Vol 180 (11) ◽  
pp. 2895-2900 ◽  
Author(s):  
Axel Mogk ◽  
Andrea Völker ◽  
Susanne Engelmann ◽  
Michael Hecker ◽  
Wolfgang Schumann ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Heat Shock ◽  
Bacterial Species ◽  
Negative Control ◽  
Expression Level ◽  
Ethanol Stress ◽  
Transcriptional Fusion ◽  
Repressor Protein ◽  
E Coli

ABSTRACT The chaperone-encoding groESL and dnaKoperons constitute the CIRCE regulon of Bacillus subtilis. Both operons are under negative control of the repressor protein HrcA, which interacts with the CIRCE operator and whose activity is modulated by the GroESL chaperone machine. In this report, we demonstrate that induction of the CIRCE regulon can also be accomplished by ethanol stress and puromycin. Introduction of the hrcA gene and a transcriptional fusion under the control of the CIRCE operator intoEscherichia coli allowed induction of this fusion by heat shock, ethanol stress, and overproduction of GroESL substrates. The expression level of this hrcA-bgaB fusion inversely correlated with the amount of GroE machinery present in the cells. Therefore, all inducing conditions seem to lead to induction via titration of the GroE chaperonins by the increased level of nonnative proteins formed. Puromycin treatment failed to induce the ςB-dependent general stress regulon, indicating that nonnative proteins in general do not trigger this response. Reconstitution of HrcA-dependent heat shock regulation of B. subtilis in E. coli and complementation of E. coli groESL mutants by B. subtilis groESL indicate that the GroE chaperonin systems of the two bacterial species are functionally exchangeable.

Of Bacteria and Men: Toxicity of 30 MEIC Chemicals to Bacteria and Humans

1993 ◽  
Vol 21 (2) ◽  
pp. 233-238 ◽  
Author(s):  
Gustaw Kerszman
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Blood Concentration ◽  
In Vitro Cytotoxicity ◽  
Human Cells ◽  
The Other ◽  
Minimal Inhibitory Concentrations ◽  
E Coli ◽  
Lethal Blood

The toxicity of chemicals (numbers 11–30 from the multicenter evaluation of in vitro cytotoxicity [MEIC] programme) to Escherichia coli and Bacillus subtilis was examined. Malathion was not detectably toxic to bacteria. Theophylline was toxic to E. coli but not to B. subtilis. All of the other chemicals were toxic to both bacteria, with minimal inhibitory concentrations (MIC) ranging from 10-5M to 1.3M. The sensitivities of both organisms to the chemicals were quite similar. A highly significant correlation could be established for the first 30 MEIC chemicals between MIC in bacteria and acute lethal blood concentration in humans. A significant correlation was also established for sets of MEIC chemicals between MIC in bacteria and the relevant endpoint concentrations in various tests employing human cells.

scholarly journals Conserved Amplification of Chemotactic Responses through Chemoreceptor Interactions

2002 ◽  
Vol 184 (18) ◽  
pp. 4981-4987 ◽  
Author(s):  
Allison C. Lamanna ◽  
Jason E. Gestwicki ◽  
Laura E. Strong ◽  
Sara L. Borchardt ◽  
Robert M. Owen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Bacterial Species ◽  
General Mechanism ◽  
Multivalent Ligands ◽  
E Coli ◽  
Receptor Interactions ◽  
Vibrio Furnissii

ABSTRACT Many bacteria concentrate their chemoreceptors at the cell poles. Chemoreceptor location is important in Escherichia coli, since chemosensory responses are sensitive to receptor proximity. It is not known, however, whether chemotaxis in other bacteria is similarly regulated. To investigate the importance of receptor-receptor interactions in other bacterial species, we synthesized saccharide-bearing multivalent ligands that are designed to cluster relevant chemoreceptors. As has been shown with E. coli, we demonstrate that the behaviors of Bacillus subtilis, Spirochaete aurantia, and Vibrio furnissii are sensitive to the valence of the chemoattractant. Moreover, in B. subtilis, chemotactic responses to serine were increased by pretreatment with saccharide-bearing multivalent ligands. This result indicates that, as in E. coli, signaling information is transferred among chemoreceptors in B. subtilis. These results suggest that interreceptor communication may be a general mechanism for modulating chemotactic responses in bacteria.

A Study on Antibacterial sensitivity character to Piper betle: A Potential for alternative medicine

2021 ◽  
pp. 4920-4924
Author(s):  
Shalsh F J ◽  
Altaif K I ◽  
Zharif DM ◽  
Hailat IA ◽  
Alqaisi KM ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Antibacterial Agent ◽  
Inhibitory Concentration ◽  
Antibacterial Property ◽  
Bacterial Species ◽  
Piper Betle ◽  
Zone Of Inhibition ◽  
E Coli ◽  
Freeze Dried

In this study we examined P. betle antibacterial property on two bacterial species namely: Streptococcus agalactiae and Escherichia coli. The extract of P. betle was prepared by mixing 2 gm of P. betle powder with 20 ml of 70% ethanol. Then, the solvent was evaporated by using vacuum evaporator and the residue was freeze dried and stored at -20 ºC. The P. betle extract divided into three different concentrations that are 50 mg/ml, 75 mg/ml and 100 mg/ml. The results revealed that the leaves of Piper betle have many benefits including antibacterial activity. The three concentrations showed an effective zone of inhibition against S. agalactiae and E. coli using Kirby-Baeur method. In addition, the minimal inhibitory concentration (MIC) confirms the effectiveness of P. betle. This study findings indicated that P. betle extract can be a new source of antibacterial agent and an alternative antibacterial for control of S. agalactiae and to certain extant against E. coli infections.

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