Effect of piperacillin on morphology and viability of gram-negative bacteria

1984 ◽  
Vol 42 ◽  
pp. 218-219
Author(s):  
R. H. Liss
Keyword(s):  
Inhibitory Concentration ◽  
Cytoplasmic Membrane ◽  
Drug Binding ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Drug Induced ◽  
Penicillin Binding Proteins ◽  
Lactam Antibiotic ◽  
Drug Free ◽  
Tube Dilution

Piperacillip (PIP) is b-[D(-)-α-(4-ethy1-2,3-dioxo-l-piperzinylcar-bonylamino)-α-phenylacetamido]-penicillanate. The broad spectrum semisynthetic β-lactam antibiotic is believed to effect bactericidal activity through its affinity for penicillin-binding proteins (PBPs), enzymes on the bacterial cytoplasmic membrane that control elongation and septation during cell growth and division. The purpose of this study was to correlate penetration and binding of 14C-PIP in bacterial cells with drug-induced lethal changes assessed by microscopic, microbiologic and biochemical methods.The bacteria used were clinical isolates of Escherichia coli and Pseudomonas aeruginosa (Figure 1). Sensitivity to the drug was determined by serial tube dilution in Trypticase Soy Broth (BBL) at an inoculum of 104 organisms/ml; the minimum inhibitory concentration of piperacillin for both bacteria was 1 μg/ml. To assess drug binding to PBPs, the bacteria were incubated with 14C-PIP (5 μg/0.09 μCi/ml); controls, in drug-free medium.

scholarly journals Antibacterial Activity of Lupinifolin from Derris reticulata and Its Effect on Cytoplasmic Membrane of Methicillin Resistant

2020 ◽  
Vol 17 (10) ◽  
pp. 1104-1112
Author(s):  
Kamol YUSOOK ◽  
Pettaya PANVONGSA
Keyword(s):  
Propidium Iodide ◽  
Nmr Spectra ◽  
Inhibitory Concentration ◽  
Cytoplasmic Membrane ◽  
Minimum Bactericidal Concentration ◽  
Membrane Integrity ◽  
Bacterial Cells ◽  
Liquid Chromatography Mass Spectrometry ◽  
Methicillin Resistant ◽  
Derris Reticulata

Lupinifolin from Derris reticulata Craib. was extracted with hexane by Soxhlet extractor and purified by crystallization. The yellow needle-shaped lupinifolin crystals were identified and confirmed by nuclear magnetic resonance (NMR) spectra and Liquid chromatography mass spectrometry (LC/MS). The lupinifolin showed minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 8 and 16 µg/ml against Methicillin resistant S. aureus (MRSA), respectively. The flow cytometry (FCM) was performed to determine the alteration of cytoplasmic membrane (CM) permeability of MRSA by using Propidium iodide (PI) 5 µg/ml as an indicator for bacterial membrane integrity. It was found that the bacterial CM permeability was effected by lupinifolin with the MIC of 8 µg/ml comparable to the control when investigated by Propidium iodide intensity. Additionally, DNA laddering assay was carried out to evaluate apoptosis in bacterial cells. It was shown that the lupinifolin has no effect on DNA fragmentation.

scholarly journals Antibacterial activity of wood distillate from residual virgin chestnut biomass

2020 ◽  
Author(s):  
Francesco Misuri ◽  
Laura Marri
Keyword(s):  
Antibacterial Activity ◽  
Inhibitory Concentration ◽  
Sustainable Use ◽  
Antibacterial Properties ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Gram Negative ◽  
Concentration Test ◽  
Mic Minimum Inhibitory Concentration ◽  
Wall Components

Abstract The antibacterial properties of a wood distillate obtained from residual virgin chestnut biomass were investigated by means of quantitative MIC (minimum inhibitory concentration) test and a whole-cell assay that specifically responds to different classes of antimicrobials on the basis of the mode of action. Results indicate that wood distillate is active against gram-positive and gram-negative bacteria related to human and/or fish diseases with a mechanism, which could mainly affect wall components and plasma membrane of the bacterial cells. These findings highlight the possible sustainable use of chestnut residues as a source of bioactive natural compounds with antibacterial properties.

Drug-induced reversible and irreversible enzyme alterations underlying drug-resistance

1958 ◽  
Vol 149 (934) ◽  
pp. 63-81 ◽  
Keyword(s):  
Folic Acid ◽  
Inhibitory Concentration ◽  
Aminobenzoic Acid ◽  
Drug Induced ◽  
Resistant Strains ◽  
Resistant Mutants ◽  
Acquired Characters ◽  
Free Media ◽  
Drug Free ◽  
Acid Precursor

p -Aminobenzoic acid-dependent M 48-34 strains of Escherichia coli grown with and without sulphathiazole (ST) were investigated with respect to the enhanced capacities they acquire simultaneously for the synthesis of folic acid and resistance. The washed cells of the sensitive strain grown in drug-free media contain a small amount of intracellularly accumulated folic acid precursor(s). The precursors are converted by the washed cells into folic acid in the presence of p -aminobenzoic acid (PABA) alone. The washed cells harvested from cultures containing a sub-inhibitory concentration of sulphathiazole contain a three-four times greater amount of intracellular folic acid precursor(s) which are converted into folic acid in the above manner. Following the utilization of the intracellular presursor(s) these cells on retesting manifest the capability of synthesizing folic acid from PABA and synthetic 2-amino- 4-hydroxy-6-carboxypteridine. This is a newly acquired character which is lacking in the cells grown in the absence of sulphathiazole. Higher intracellular folic acid-precursor accumula­tion and ability to synthesize folic acid from PABA and synthetic pteridine is possessed by the strains made resistant by successive transfers in the increasing concentrations of sulpha­thiazole. During these transfers, the amounts of sulphathiazole are so graded that the cells in the inocula are capable of surviving from 65 to 87·7% and therefore, the chances of selecting pre-existant resistant mutants, believed to occur at the rate of 10 ‒8 to 10 ‒9 , are reduced to a minimum or improbable level. The strain which is made resistant to 1·0 μ g ST by four successive transfers in graded amounts of sulphathiazole loses the acquired synthetic and resistance characters following three successive transfers in drug-free media, the strain made resistant to 15·0 μ g ST still possessed a fraction of the acquired abilities after twenty successive drug-free transfers, and the strain which was made resistant to 40 μ g ST did not show any decrease in the acquired characters after thirty successive drug-free transfers. It is to be noted that when the strain reversibly resistant to 1·0 μ g ST is grown in sulphathiazole and an antagonist concentration of PABA they fail to manifest the two characters. Similar concen­trations of PABA present during the growth of the resistant strains do not alter to any degree the acquired characters. Colonies of the parent sensitive cells appearing on agar plates con­taining various concentrations of sulphathiazole inoculated into drug-free media yield descendant cells which manifest the two characters, but lost them after two or three successive drug-free transfers, in a manner similar to 1·0 μ g ST-resistant cells discussed above.

Heavy-metal resistance in Gram-negative bacteria isolated from Kongsfjord, Arctic

2015 ◽  
Vol 61 (6) ◽  
pp. 429-435 ◽  
Author(s):  
C.S. Neethu ◽  
K.M. Mujeeb Rahiman ◽  
A.V. Saramma ◽  
A.A. Mohamed Hatha
Keyword(s):  
Heavy Metals ◽  
Inhibitory Concentration ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
The Arctic ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Isolation And Characterization ◽  
Tube Dilution

Isolation and characterization of heterotrophic Gram-negative bacteria was carried out from the sediment and water samples collected from Kongsfjord, Arctic. In this study, the potential of Arctic bacteria to tolerate heavy metals that are of ecological significance to the Arctic (selenium (Se), mercury (Hg), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn)) was investigated. Quantitative assay of 130 isolates by means of plate diffusion and tube dilution methods was carried out by incorporation of different concentrations of metals. Growth in Se and Pb at a concentration of 3000 μg/L was significantly lower (P ≤ 0.0001) than at 2000 μg/L. The minimum inhibitory concentration for Cd and Hg was 50 μg/L (P ≤ 0.0001, F = 264.23 and P ≤ 0.0001, F = 291.08, respectively) even though in the tube dilution test, Hg-containing tubes showed much less growth, revealing its superior toxicity to Cd. Thus, the level of toxicity of heavy metals was found to be in the order of Hg > Cd > Cu > Zn > Pb > Se. Multiple-metal-resistant isolates were investigated for their resistance against antibiotics, and a positive correlation was observed between antibiotic and metal resistance for all the isolates tested. The resistant organisms thus observed might influence the organic and inorganic cycles in the Arctic and affect the ecosystem.

scholarly journals Antibacterial characteristics of orange pigment extracted from Monascus pigments against Escherichia coli

2016 ◽  
Vol 34 (No. 3) ◽  
pp. 197-203 ◽  
Author(s):  
Zhao Guo-Ping ◽  
Li Ying-Qiu ◽  
Yang Jie ◽  
Cui Kai-Yu
Keyword(s):  
Escherichia Coli ◽  
Inhibitory Concentration ◽  
Cytoplasmic Membrane ◽  
Inhibition Zone ◽  
Bacterial Membrane ◽  
Bacterial Cells ◽  
Orange Pigment ◽  
E Coli ◽  
Monascus Pigments ◽  
Egg Pc

The antibacterial characteristics of orange pigment, which is one of the Monascus pigments, against Escherichia coli were investigated. Orange pigment exhibited strong antibacterial activity against E. coli evidenced by an increase in the diameter of inhibition zone with orange pigment treatment. The concentration of 2.5 mg/ml was the minimum inhibitory concentration of orange pigment against E. coli. Scanning electron microscopy revealed that orange pigment could damage bacterial cells, eventually resulting in cell death. The increase in the electric conductivity of bacterial cell suspensions suggested that the cytoplasmic membrane was broken by treatment with orange pigment. The result of orange pigment incorporation into egg PC further demonstrated the interaction between orange pigment and the phospholipid led to the disruption of bacterial membrane.

Antimicrobial and cytotoxic activity of Macrophomina phaseolina isolated from gummosis infected citrus reticulata

2013 ◽  
pp. 125-133
Author(s):  
Rubal C Das ◽  
Rajib Banik ◽  
Robiul Hasan Bhuiyan ◽  
Md Golam Kabir
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Brine Shrimp ◽  
Inhibitory Concentration ◽  
Lethal Dose ◽  
Macrophomina Phaseolina ◽  
Chloroform Extract ◽  
Citrus Reticulata ◽  
Gram Negative Bacteria ◽  
Gram Negative

Macrophomina phaseolina is one of the pathogenic organisms of gummosis disease of orange tree (Citrus reticulata). The pathogen was identified from the observation of their colony size, shape, colour, mycelium, conidiophore, conidia, hyaline, spore, and appressoria in the PDA culture. The crude chloroform extracts from the organism showed antibacterial activity against a number of Gram positive and Gram-negative bacteria. The crude chloroform extract also showed promising antifungal activity against three species of the genus Aspergillus. The minimum inhibitory concentration (MIC) of the crude chloroform extract from M. phaseolina against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Shigella sonnie were 128 ?gm, 256 ?gm, 128 ?gm and 64 ?gm/ml respectively. The LD50 (lethal dose) values of the cytotoxicity assay over brine shrimp of the crude chloroform extract from M. phaseolina was found to be 51.79 ?gm/ml. DOI: http://dx.doi.org/10.3329/cujbs.v5i1.13378 The Chittagong Univ. J. B. Sci.,Vol. 5(1 &2):125-133, 2010

scholarly journals Prevalence and Carbapenem Resistance of Acinetobacter baumannii and Other Than A. baumannii Isolates From Intensive Care Units (ICUs) and non-ICUs

2020 ◽  
Vol 41 (S1) ◽  
pp. s356-s357
Author(s):  
Tomasz Kasperski ◽  
Biophage Pharma S.A. Kraków ◽  
Agnieszka Chmielarczyk ◽  
Monika Pomorska-Wesolowska ◽  
Dorota Romaniszyn ◽  
...  
Keyword(s):  
Intensive Care ◽  
Inhibitory Concentration ◽  
Carbapenem Resistance ◽  
Diagnostic Methods ◽  
Clinical Settings ◽  
Gram Negative Bacteria ◽  
Carbapenem Resistant ◽  
Therapeutic Problem ◽  
Hospital Associated Infections ◽  
Very High

Background:Acinetobacter spp are gram-negative bacteria that have emerged as a leading cause of hospital-associated infections, most often in the intensive care unit (ICU) setting. This is particularly important in Poland, where the prevalence of A. baumannii in various types of infections, including bloodstream infection (BSI), pneumonia, skin and soft-tissue infection (SSTI), and urinary tract infection (UTI) is higher than in neighboring countries. Recently, other Acinetobacter spp, including A. lwoffii or A. ursingii, have been found to be clinically relevant. In Poland, we have also observed a very rapid increase in antimicrobial resistance, significantly faster for A. baumannii than for other nosocomial pathogens. Methods: A study was conducted in 12 southern Polish hospitals, including 3 ICUs, from January 1 to December 31, 2018. Only adult hospitalized patients were included. Strains were identified using the MALDI-TOF method. Carbapenem resistance was determined using the minimum inhibitory concentration (MIC). Results: During the study, 194 strains belonging to the Acinetobacter genus were isolated. A. baumannii was the dominant species, 88.1% (n = 171), and 23 isolates (11.9%) were other Acinetobacter spp: A. ursingii (n = 5), A. lwofii (n = 4), A. haemolyticus (n = 4), A. junii (n = 3), A. radioresistens (n = 2), A. bereziniae (n = 2), and A. johnsonii (n = 2). Moreover, 15 Acinetobacter strains were collected from ICUs. The most Acinetobacter strains were isolated from SSTIs (n = 115) from non-ICU settings. Non–A. baumannii strains were also most frequently isolated from SSTIs; they constituted 11.3% of all Acinetobacter strains from this type of infection (n = 13). The total Acinetobacter prevalence was 2.6%, whereas the prevalence in the ICU setting was 7%. Acinetobacter prevalence in SSTIs was 10.4%. In pneumonia, Acinetobacter prevalence was 18.6% for ICUs (n = 13) and 2.7% for non-ICUs (n = 46). Strains from UTIs were isolated only with the non-ICU setting, and their prevalence was 0.7% (n = 14). More than half of the tested strains (52.1%) were resistant to carbapenems, but all non–A. baumannii strains were susceptible. The highest resistance to carbapenems was among strains from pneumonia cases in ICUs (58.3%) and resistance among all strains isolated from ICU was 50%. However, even higher resistance was noted among SSTI strains from non-ICUs (61.7%). Conclusions: Increasingly, more than A. baumannii, other species among Acinetobacter strains are isolated from patients hospitalized in Polish hospitals. To assess the significance of non–A. baumannii spp in clinical settings, precise species identification is needed. Therefore, the diagnostic methods used must be improved. Carbapenem-resistant A. baumannii infections are the biggest problem in pneumonia patients in ICUs and in SSTI patients in other hospital departments. Carbapenem resistance occurs in a very high percentage of A. baumannii strains; among non–A. baumannii strains it is not yet a therapeutic problem.Funding: NoneDisclosures: None

scholarly journals Evaluation of antimicrobial activity of the endophytic actinomycete R18(6) against multiresistant Gram-negative bacteria

2016 ◽  
Vol 88 (1) ◽  
pp. 155-163 ◽  
Author(s):  
Tiele Carvalho ◽  
Sueli Van Der Sand
Keyword(s):  
Antimicrobial Activity ◽  
Inhibitory Concentration ◽  
Proteolytic Enzymes ◽  
Gram Negative Bacteria ◽  
Bacteriostatic Activity ◽  
Submerged Cultures ◽  
Gram Negative ◽  
Endophytic Actinomycete ◽  
Endophytic Actinomycetes ◽  
Antimicrobial Substances

Endophytic actinomycetes are promising sources of antimicrobial substances. This study evaluates the activity of metabolites produced by the endophytic actinomycete R18(6) against Gram-negative bacteria multiresistant to antimicrobials. R18(6) isolate was grown in submerged cultures under different conditions: carbon source, temperature, pH and incubation time to optimize antimicrobials production. The actinomycete grown in base medium supplemented with 1% glucose, pH 6.5 and incubation at 30 ºC for 96 h with shaking at 100 rpm, exhibited the highest activity against the used Gram-negative bacteria. Minimum inhibitory concentration (MIC) of the crude extract produced by the microorganism varied between 1/32 and 1/256. It had bactericide or bacteriostatic activity, depending on the Gram-negative organism. The active extract was stable at high temperatures, and unstable in medium containing proteolytic enzymes. Micromorphology of R18(6) was investigated by optical and scan microscopy, revealing that it was morphologically similar to the genusStreptomyces.

Production and use of monoclonal antibodies for identification of Bradyrhizobium japonicum strains

1988 ◽  
Vol 34 (1) ◽  
pp. 88-92 ◽  
Author(s):  
D. Velez ◽  
J. D. Macmillan ◽  
L. Miller
Keyword(s):  
Monoclonal Antibodies ◽  
Bradyrhizobium Japonicum ◽  
Chemical Nature ◽  
Periodate Oxidation ◽  
Enzyme Linked Immunosorbent Assay ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Gram Negative ◽  
Polyclonal Antisera ◽  
Somatic Antigens

Thirteen murine hybridomas capable of producing monoclonal antibodies to somatic antigens on Bradyrhizobium japonicum were developed and an indirect enzyme-linked immunosorbent assay was used to test reactivity of the antibodies against 20 strains of B. japonicum. Although polyclonal antisera from mice immunized with strains of B. japonicum reacted with bacterial cells of all 20 strains, individual monoclonals were more specific. Some antibodies reacted with as few as 2 and one with as many as 11 strains. On the basis of reactivity with the set of 13 monoclonal antibodies, the 20 strains of B. japonicum could be divided arbitrarily into five groups. Three of five monoclonal antibodies tested reacted with bacteroids taken directly from soybean nodules. One monoclonal bound to cells of five species of Rhizobium, but none of the 13 reacted with gram-negative bacteria representing six other genera. Treatment of cells with reagents and heat indicated the chemical nature of the antigens to five of the monoclonals. Antigen reactive with one antibody was destroyed by periodate oxidation indicating that it was a polysaccharide. Two antigens were probably proteins as they could be digested by trypsin and denatured by heat. Two others were inactivated by all three treatments suggesting they were glycoproteins.

Interaction of Gram-Negative Bacteria with the Lysosomal Fraction of Polymorphonuclear Leukocytes II. Changes in the Cell Envelope of Escherichia coli

1970 ◽  
Vol 1 (3) ◽  
pp. 311-318
Author(s):  
D. Friedberg ◽  
I. Friedberg ◽  
M. Shilo
Keyword(s):  
Escherichia Coli ◽  
Polymorphonuclear Leukocytes ◽  
Cytoplasmic Membrane ◽  
Morphological Changes ◽  
Cell Envelope ◽  
Gram Negative Bacteria ◽  
Intact Cells ◽  
Lysosomal Fraction ◽  
E Coli ◽  
Absorbing Material

Interaction of lysosomal fraction with Escherichia coli caused damage to the cell envelope of these intact cells and to the cytoplasmic membrane of E. coli spheroplasts. The damage to the cytoplasmic membrane was manifested in the release of 260-nm absorbing material and β-galactosidase from the spheroplasts, and by increased permeability of cryptic cells to O -nitrophenyl-β- d -galactopyranoside; damage to the cell wall was measured by release of alkaline phosphatase. Microscope observation showed morphological changes in the cell envelope.

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