Diversity of the mechanisms of bactericidal activity of human serum complement against E. coli strains isolated from patients with bacteremia

1998 ◽  
Vol 35 (6-7) ◽  
pp. 385
Author(s):  
G. Mokracka-Latajka ◽  
B. Krzyżanowska ◽  
J. Grabińska
Keyword(s):  
Human Serum ◽  
Bactericidal Activity ◽  
Serum Complement ◽  
E Coli

scholarly journals Survival of Carbapenem-Resistant Klebsiella pneumoniae Sequence Type 258 in Human Blood

2017 ◽  
Vol 61 (4) ◽  
Author(s):  
Frank R. DeLeo ◽  
Scott D. Kobayashi ◽  
Adeline R. Porter ◽  
Brett Freedman ◽  
David W. Dorward ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Human Serum ◽  
Host Defense ◽  
Human Blood ◽  
Bactericidal Activity ◽  
Sequence Type ◽  
Serum Complement ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Normal Human

ABSTRACT Klebsiella pneumoniae is a prominent cause of nosocomial infections worldwide. Bloodstream infections caused by carbapenem-resistant K. pneumoniae, including the epidemic lineage known as multilocus sequence type 258 (ST258), are difficult to treat, and the rate of mortality from such infections is high. Thus, it is imperative that we gain a better understanding of host defense against this pathogen as a step toward developing novel therapies. Here we tested the hypothesis that the resistance of ST258 to bactericidal components of human blood, such as serum complement, is linked to virulence capacity in the context of bacteremia. There was significant variance in the survival of ST258 clinical isolates in heparinized human blood or normal human serum. The rate of survival of ST258 isolates in human blood was, in general, similar to that in normal human serum, suggesting a prominent role for complement (rather than leukocytes) in the healthy host defense against ST258 isolates and related organisms. Indeed, deposition of serum complement—the C5b to C9 (C5b-C9) membrane attack complex—onto the surface of ST258 isolates accompanied serum bactericidal activity. Human serum treated with pharmacological inhibitors of complement, depleted of antibody, or heated at 56°C for 30 min had significantly reduced or absent bactericidal activity. In contrast to heparinized blood from humans, that from BALB/c mice lacked bactericidal activity toward the ST258 isolates tested, but the virulence of these ST258 isolates in a mouse bacteremia model was inexplicably limited. Our data highlight the importance of the complement system in host defense against ST258 bacteremia, and we propose that there is the potential to enhance complement-mediated bactericidal activity using an antibody-based approach.

scholarly journals THE ACTIVATING EFFECT OF CALCIUM ON A BACTERICIDAL SUBSTANCE FOR BACILLUS SUBTILIS IN HUMAN SERUM

1950 ◽  
Vol 92 (2) ◽  
pp. 101-111 ◽  
Author(s):  
Ralph F. Jacox
Keyword(s):  
Bacillus Subtilis ◽  
Human Serum ◽  
Bactericidal Activity ◽  
Bacterial Infections ◽  
Coronary Occlusion ◽  
Bactericidal Effect ◽  
Serum Complement ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Acute Coronary Occlusion

An enhanced bactericidal activity of human serum for B. subtilis develops during many different forms of illness, e.g. carcinoma, virus and bacterial infections, and during acute coronary occlusion. This increased bactericidal effect cannot be related to leucocytosis, fever, serum complement, C-reactive protein, or a specific antibody reaction. The serum bactericidal factor becomes inactive in decalcified serum, but active again when optimal concentrations of calcium are added. Magnesium does not cause reactivation.

scholarly journals The Synthesis and Bioloqical Properties of a 1-(2-Methylpyridin-4-yl) Olivacine Derivative

2005 ◽  
Vol 73 (3) ◽  
pp. 101-112
Author(s):  
Ryszard Jasztold-Howorko ◽  
Włodzimierz Doroszkiewicz ◽  
Gabriela Bugla-Płoskońska ◽  
Alain Croisy ◽  
Daniele Carrez
Keyword(s):  
Human Serum ◽  
Bactericidal Activity ◽  
Normal Human Serum ◽  
Cytostatic Activity ◽  
E Coli ◽  
L1210 Cells ◽  
Inhibition Of Growth ◽  
No Inhibition ◽  
Normal Human

Starting from 2-(6-methoxy-1-methyl-9H-carbazol-2-yl)ethylamine and 2-methylisonicotinic acid, 9-hydroxy-5,6-dimethyl-1-(2-methylpyridin-4-yl)-6H-pyrido[4,3-b]carbazole (5) was obtained. The new compound showed significant cytostatic activity for cultured L1210 cells and no inhibition of growth of the E. coli O56 strain was observed. The bactericidal activity of normal human serum against E. coli O56 was not affected by the examined compound 5 and its isomer 4.

Host defense against Neisseria meningitidis requires a complement-dependent bactericidal activity

Science ◽  
1979 ◽  
Vol 205 (4403) ◽  
pp. 298-299 ◽  
Author(s):  
A Nicholson ◽  
IH Lepow
Keyword(s):  
Human Serum ◽  
Host Defense ◽  
Bactericidal Activity ◽  
Recurrent Infection ◽  
Fluid Phase ◽  
Normal Serum ◽  
Serum Complement ◽  
Intracellular Killing ◽  
Complement Components ◽  
Neisseria Species

Some individuals, with severe or recurrent infection with Neisseria species, have been identified as lacking a component in the terminal attack sequence of complement (complement components 5 to 9). The relevance of the terminal attack sequence to various phases of host defense was tested with the use of the C-11 strain of meningococci and human serum genetically deficient in complement component 8 (C8-D). The C8-D serum was comparable to normal serum in supporting ingestion and intracellular killing by leukocytes but was not bactericidal in the fluid phase unless reconstituted with C8. Thus, serum complement-dependent bactericidal activity may be especially critical for the host's defense against invasive Neisseria species.

scholarly journals Inactivation of classical and alternative pathway-activated bactericidal activity of human serum by sodium polyanetholsulfonate

1977 ◽  
Vol 5 (3) ◽  
pp. 278-284
Author(s):  
W H Traub ◽  
I Kleber
Keyword(s):  
Human Serum ◽  
Bactericidal Activity ◽  
Alternative Pathway ◽  
Inhibitory Effect ◽  
Final Concentration ◽  
Classical Pathway ◽  
Control Strain ◽  
E Coli ◽  
Alternative Complement ◽  
And Control

Sodium polyanetholsulfonate (SPS) at a final concentration of at least 250 microng/ml (0.025%) was required for inhibition of the bactericidal activity of 80% (vol/vol) of fresh human serum against "promptly serum-sensitive" strains of Serratia marcescens and control strain Escherichia coli C, i.e., for inhibition of the classical pathway of complement activation. In contrast, SPS at 125 microng/ml (0.0125%) was sufficient for neutralization of the bactericidal activity of 80% (vol/vol) fresh human serum against "delayed serum-sensitive" strains of S. marcescens known to activate the alternative pathway of human complement. Addition of up to 500 microng of SPS per ml to 80% (vol/vol) fresh human serum failed to neutralize transferrin-mediated, "late" bacteriostasis against control strain E. coli C, an effect that was demonstrable only after prolonged, i.e., overnight, incubation of the test strain. However, this late inhibitory effect against E. coli C was not observed in SPS-treated 20% (vol/vol) fresh human serum or in 10 or 20% (vol/vol) conventionally heat-inactivated human serum. Immunoelectrophoretic examination disclosed that SPS did not precipitate transferrin from either fresh or heat-inactivated human serum. Thus, SPS, at 250 microng/ml, was demonstrated to be sufficient for the inhibition of both classical and alternative complement pathway-activated bactericidal activity of 80% (vol/vol) human serum. However, SPS at a concentration of 500 microng/ml failed to antagonize one antimicrobial system of 80% (vol/vol) human serum, namely transferrin-mediated bacteriostasis.

scholarly journals Bactericidal Activity, Absence of Serum Effect, and Time-Kill Kinetics of Ceftazidime-Avibactam against β-Lactamase-Producing Enterobacteriaceae and Pseudomonas aeruginosa

2014 ◽  
Vol 58 (9) ◽  
pp. 5297-5305 ◽  
Author(s):  
Tiffany R. Keepers ◽  
Marcela Gomez ◽  
Chris Celeri ◽  
Wright W. Nichols ◽  
Kevin M. Krause
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Human Serum ◽  
Bactericidal Activity ◽  
Minimum Bactericidal Concentration ◽  
Wild Type ◽  
Content Type ◽  
Positive Isolate ◽  
New Treatment ◽  
Time Kill ◽  
Kinetics Of

ABSTRACTAvibactam, a non-β-lactam β-lactamase inhibitor with activity against extended-spectrum β-lactamases (ESBLs), KPC, AmpC, and some OXA enzymes, extends the antibacterial activity of ceftazidime against most ceftazidime-resistant organisms producing these enzymes. In this study, the bactericidal activity of ceftazidime-avibactam against 18Pseudomonas aeruginosaisolates and 15Enterobacteriaceaeisolates, including wild-type isolates and ESBL, KPC, and/or AmpC producers, was evaluated. Ceftazidime-avibactam MICs (0.016 to 32 μg/ml) were lower than those for ceftazidime alone (0.06 to ≥256 μg/ml) against all isolates except for 2P. aeruginosaisolates (1blaVIM-positive isolate and 1blaOXA-23-positive isolate). The minimum bactericidal concentration/MIC ratios of ceftazidime-avibactam were ≤4 for all isolates, indicating bactericidal activity. Human serum and human serum albumin had a minimal effect on ceftazidime-avibactam MICs. Ceftazidime-avibactam time-kill kinetics were evaluated at low MIC multiples and showed time-dependent reductions in the number of CFU/ml from 0 to 6 h for all strains tested. A ≥3-log10decrease in the number of CFU/ml was observed at 6 h for allEnterobacteriaceae, and a 2-log10reduction in the number of CFU/ml was observed at 6 h for 3 of the 6P. aeruginosaisolates. Regrowth was noted at 24 h for some of the isolates tested in time-kill assays. These data demonstrate the potent bactericidal activity of ceftazidime-avibactam and support the continued clinical development of ceftazidime-avibactam as a new treatment option for infections caused byEnterobacteriaceaeandP. aeruginosa, including isolates resistant to ceftazidime by mechanisms dependent on avibactam-sensitive β-lactamases.

Evaluation of Fruit Extracts Influence on the Susceptibility of Escherichia Coli Rods to the Bactericidal Action of Human Serum

2021 ◽  
Author(s):  
Agnieszka Cisowska ◽  
Janina Gabrielska
Keyword(s):  
Escherichia Coli ◽  
Human Serum ◽  
Mechanisms Of Action ◽  
Bactericidal Action ◽  
E Coli ◽  
Fruit Extracts ◽  
Extract Concentration ◽  
Japanese Quince ◽  
Normal Human ◽  
Dog Rose

Abstract This study determined the influence of the methanol (ME) and water (WE) fruit extracts obtained from eight species of Rosaceae and Grossulariacae family on the susceptibility of Escherichia coli rods to the lytic action of normal human serum (NHS). Bacteria were incubated for 24 h in tryptic soy broth with varying concentrations (1, 5, 10, 20, 30, 40, and 50 mg ml-1) of raspberry, cherry, hawthorn, dog rose, gooseberry, chokeberry, quince, and Japanese quince extracts and then the bactericidal activity of NHS was established. We found that the resistance of E. coli rods to the bactericidal action of serum was altered by prior incubation with all tested extracts and was dependent on plant extract concentration. Among the tested extracts, gooseberry (both ME and WE), raspberry ME and cherry WE were responsible for the most profound changes in serum resistance of E. coli rods. Evaluation of the antimicrobial mechanisms of action of phenolics-rich plant extracts has the potential to impact the development of novel compounds with promising applications in food and biopharmaceutical industry or medical approaches to preventing and treating pathogenic infections.

Effects of Water Source, Dilution, Storage, and Bacterial and Fecal Loads on the Efficacy of Electrolyzed Oxidizing Water for the Control of Escherichia coli O157:H7

2004 ◽  
Vol 67 (7) ◽  
pp. 1377-1383 ◽  
Author(s):  
S. M. L. STEVENSON ◽  
S. R. COOK ◽  
S. J. BACH ◽  
T. A. McALLISTER
Keyword(s):  
Escherichia Coli ◽  
Bactericidal Activity ◽  
Storage Temperature ◽  
Uv Light ◽  
Tap Water ◽  
Organic Matter Content ◽  
Water Source ◽  
Deionized Water ◽  
Escherichia Coli O157 ◽  
E Coli

To evaluate the potential of using electrolyzed oxidizing (EO) water for controlling Escherichia coli O157:H7 in water for livestock, the effects of water source, electrolyte concentration, dilution, storage conditions, and bacterial or fecal load on the oxidative reduction potential (ORP) and bactericidal activity of EO water were investigated. Anode and combined (7:3 anode:cathode, vol/vol) EO waters reduced the pH and increased the ORP of deionized water, whereas cathode EO water increased pH and lowered ORP. Minimum concentrations (vol/vol) of anode and combined EO waters required to kill 104 CFU/ml planktonic suspensions of E. coli O157:H7 strain H4420 were 0.5 and 2.0%, respectively. Cathode EO water did not inhibit H4420 at concentrations up to 16% (vol/vol). Higher concentrations of anode or combined EO water were required to elevate the ORP of irrigation or chlorinated tap water compared with that of deionized water. Addition of feces to EO water products (0.5% anode or 2.0% combined, vol/vol) significantly reduced (P < 0.001) their ORP values to <700 mV in all water types. A relationship between ORP and bactericidal activity of EO water was observed. The dilute EO waters retained the capacity to eliminate a 104 CFU/ml inoculation of E. coli O157:H7 H4420 for at least 70 h regardless of exposure to UV light or storage temperature (4 versus 24°C). At 95 h and beyond, UV exposure reduced ORP, significantly more so (P < 0.05) in open than in closed containers. Bactericidal activity of EO products (anode or combined) was lost in samples in which ORP value had fallen to ≤848 mV. When stored in the dark, the diluted EO waters retained an ORP of >848 mV and bactericidal efficacy for at least 125 h; with refrigeration (4°C), these conditions were retained for at least 180 h. Results suggest that EO water may be an effective means by which to control E. coli O157:H7 in livestock water with low organic matter content.

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