Bioisomerization kinetics of γ-HCH and biokinetics of Pseudomonas aeruginosa degrading technical HCH

2007 ◽  
Vol 35 (1) ◽  
pp. 12-19 ◽  
Author(s):  
Bharat Lodha ◽  
Praveena Bhat ◽  
M. Suresh Kumar ◽  
Atul N. Vaidya ◽  
Sandeep Mudliar ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Kinetics Of

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.

Growth of Salmonella Enteritidis in the presence of quorum sensing signaling compounds produced by Pseudomonas aeruginosa

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Weijia He ◽  
Huamei Yang ◽  
Xiang Wang ◽  
Hongmei Li ◽  
Qingli Dong
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Salmonella Enteritidis ◽  
Culture Supernatant ◽  
Lag Time ◽  
Bacterial Communication ◽  
Homoserine Lactones ◽  
Positive Effects ◽  
Kinetics Of

Abstract Quorum sensing (QS) can exist in food-related bacteria and potentially affect bacterial growth through acyl-homoserine lactones (AHLs). To verify the role of QS compounds in the cell-free supernatant, this study examined the effect of supernatant extracted from Pseudomonas aeruginosa culture on the growth kinetics of Salmonella Enteritidis. The results showed that the lag time (λ) of S. Enteritidis was apparently reduced (p < 0.05) under the influence of P. aeruginosa culture supernatant compared with the S. Enteritidis culture supernatant. HPLC-MS/MS test demonstrated that AHLs secreted by P. aeruginosa were mainly C14-HSL with a content of 85.71 μg/mL and a small amount of 3-oxo-C12-HSL. In addition, the commercially synthetic C14-HSL had positive effects on the growth of S. Enteritidis, confirming once again that the growth of S. Enteritidis was affected by AHL metabolized by other bacteria and the complexity of bacterial communication.

scholarly journals Efficiency and Kinetics of Assam Crude Oil Degradation by Pseudomonas Aeruginosa AKS1 and Bacillus Sp. AKS2

2021 ◽  
Author(s):  
Bobby Chettri ◽  
Ningombam Anjana Singha ◽  
Arvind Kumar Singh
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Crude Oil ◽  
Liquid Medium ◽  
Half Life ◽  
Liquid Culture ◽  
Oil Degradation ◽  
Biodegradation Rate ◽  
Emulsification Index ◽  
Crude Oil Degradation ◽  
Kinetics Of

Abstract We report kinetics of Assam crude oil degradation by Pseudomonas aeruginosa AKS1 and Bacillus sp. AKS2, both isolated from Assam refinery sediments. The isolates exhibited appreciable degrees of hydrophobicity, emulsification index and biosurfactant production. Crude oil degradation efficiency of isolates was assessed in (1) liquid medium amended with 1% v/v crude oil and (2) microcosm sediments (125 mg crude oil/ 10 g sand). In liquid culture, the biodegradation rate (k) and half-life (t1/2) values were found to be 0.0383 day -1 and 18.09 days for P. aeruginosa AKS1, and 0.0204 day -1 and 33.97 days in case of Bacillus sp. AKS2. In microcosm sand sediments, the estimated biodegradation rate (k) and half-life (t 1/2) values were 0.0138 day -1 and 50 days for P. aeruginosa AKS1, and 0.0113 day -1 and 61.34 days in case of Bacillus sp. AKS2. The level of nutrient treatment in microcosm sand sediment was 125 µg N & 62.5 µg P/g sediment in case of P. aeruginosa AKS1 and 375 µg N & 37.5 µg P/g sediment in case of Bacillus sp. AKS2. In microcosms without inorganic nutrients, biodegradation rate (k) and half-life (t1/2) values were found to be 0.0069 day -1 and 100 days for P. aeruginosa AKS1 and for Bacillus sp. AKS2, the respective values were found to be 0.0046 day -1 and 150.68 days. Our data provides important information for predictive hydrocarbon degradation in liquid medium and contaminated sediments.

scholarly journals KINETICS OF DIRHAMNOLIPIDS BIOSYNTHESIS AND RHAMNOSYLTRANSFERASE 2 ACTIVITY IN THE PRESENCE OF PSEUDOMONAS AERUGINOSA SIGNAL QUINOLONE

2014 ◽  
Vol 0 (1(25)) ◽  
pp. 45-52
Author(s):  
Мухліс Абедалабас ◽  
М. Б. Галкін ◽  
Є. Ю. Пахомова ◽  
Т. О. Філіпова
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Kinetics Of

Kinetics of nutrient enhanced crude oil degradation by Pseudomonas aeruginosa AKS1 and Bacillus sp. AKS2 isolated from Guwahati refinery, India

2016 ◽  
Vol 216 ◽  
pp. 548-558 ◽  
Author(s):  
Bobby Chettri ◽  
Arghya Mukherjee ◽  
James S. Langpoklakpam ◽  
Dhrubajyoti Chattopadhyay ◽  
Arvind K. Singh
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Crude Oil ◽  
Oil Degradation ◽  
Bacillus Sp ◽  
Crude Oil Degradation ◽  
Kinetics Of

scholarly journals Uptake and intracellular activity of NM394, a new quinolone, in human polymorphonuclear leukocytes.

1996 ◽  
Vol 40 (3) ◽  
pp. 739-742 ◽  
Author(s):  
M Ozaki ◽  
K Komori ◽  
M Matsuda ◽  
R Yamaguchi ◽  
T Honmura ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Infection ◽  
Polymorphonuclear Leukocytes ◽  
Concentration Ratio ◽  
Extracellular Concentration ◽  
Intracellular Activity ◽  
Subsequent Elution ◽  
Active Transport System ◽  
Human Polymorphonuclear Leukocytes ◽  
Kinetics Of

The uptake of NM394, a new quinolone, by and its subsequent elution from human polymorphonuclear leukocytes were studied and compared with those of ofloxacin and ciprofloxacin. The kinetics of the uptake of NM394 was similar to that of ciprofloxacin. The maximum intracellular-to-extracellular concentration ratio was 12.3, compared with 8.6 for ciprofloxacin and 4.9 for ofloxacin at the extracellular concentration of 20 micrograms/ml. The elution of NM394 from human polymorphonuclear leukocytes occurs relatively slowly; 5 min after the removal of extracellular NM394, nearly 100% still remained in polymorphonuclear leukocytes, compared with ofloxacin, which was so rapidly eluted that only 12% remained. The uptake of NM394 was significantly decreased at 4 degrees C and by the presence of NaCN but was not affected by the presence of L-glycine, L-leucine, L-serine, adenosine, or NaF. NM394 showed intracellular activity at a concentration of 0.1 microgram/ml that significantly reduced the number of phagocytosed Pseudomonas aeruginosa cells with 2 h of incubation. These results suggest that uptake of NM394 by human polymorphonuclear leukocytes occurs via an active transport system differing from that of ofloxacin, whose uptake is affected by the presence of L-glycine and L-leucine, and that once accumulated, NM394 remains intracellularly active and participates in protection against bacterial infection.

scholarly journals A mathematical model-based analysis of the time–kill kinetics of ceftazidime/avibactam against Pseudomonas aeruginosa

2018 ◽  
Vol 73 (5) ◽  
pp. 1295-1304 ◽  
Author(s):  
Sherwin K B Sy ◽  
Luning Zhuang ◽  
Huiming Xia ◽  
Marie-Eve Beaudoin ◽  
Virna J Schuck ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Pseudomonas Aeruginosa ◽  
Model Based ◽  
Time Kill ◽  
Kinetics Of ◽  
Model Based Analysis

Pseudomonas aeruginosa lectins I and II and their interaction with human airway cilia

2005 ◽  
Vol 119 (8) ◽  
pp. 595-599 ◽  
Author(s):  
Marco Mewe ◽  
Denis Tielker ◽  
Robert Schönberg ◽  
Melitta Schachner ◽  
Karl-Erich Jaeger ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Joint Action ◽  
Mammalian Cells ◽  
Time Dependent ◽  
Carbohydrate Binding ◽  
Dependent Manner ◽  
Similar Time ◽  
Airway Cilia ◽  
Kinetics Of ◽  
Ciliary Beat

The bacterium Pseudomonas aeruginosa (PA) produces two carbohydrate binding lectins, designated PA lectin-I and lectin-II (PA-IL, PA-IIL). Both lectins are used by the bacterium to adhere to the glycocalyx of mammalian cells. In addition, the lectins immobilize ciliary beat. The kinetics of ciliary beat inhibition by each individual lectin have been analysed; however, their joint action on cilia has not been reported. Here we demonstrate that PA-IL and PA-IIL inhibit ciliary beat in a similar time-dependent manner. If applied simultaneously, ciliary beat inhibition after five hours of incubation was weaker than if each lectin was applied separately. Thus it can be hypothesized that the lectins compete for the same binding site(s) of the glycocalyx. Sugar inhibition experiments demonstrate that D-galactose and L-fucose inhibit both lectins, although clear preferences of D-galactose for PA-IL and of L-fucose for PA-IIL exist. These interactions have to be kept in mind when designing sugar-based therapies.

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