scholarly journals Antimicrobial Activity of L-Lysine and Poly-L-Lysine with Pulsed Electric Fields

2021 ◽  
Vol 11 (6) ◽  
pp. 2708
Author(s):  
Jurgita Švedienė ◽  
Vitalij Novickij ◽  
Rokas Žalnėravičius ◽  
Vita Raudonienė ◽  
Svetlana Markovskaja ◽  
...  
Keyword(s):  
Electric Fields ◽  
Pulsed Electric Fields ◽  
Antimicrobial Treatment ◽  
Treatment Development ◽  
E Coli ◽  
Yeast Fungi ◽  
New Treatment ◽  
First Time ◽  
Resistant Microorganism ◽  
Susceptibility Patterns

For the first time, the possibility to use L-lysine (Lys) and poly-L-lysine (PLL) as additives with pulsed electric fields (PEF) for antimicrobial treatment is reported. The antimicrobial efficacy of Lys and PLL for Escherichia coli, Staphylococcus aureus, Trichophyton rubrum and Candida albicans was determined. Inactivation of microorganisms was also studied by combining Lys and PLL with PEF of 15 and 30 kV/cm. For PEF treatment, pulses of 0.5, 1, 10 or 100 μs were applied in a sequence of 10 to 5000 at 1 kHz frequency. The obtained results showed that 100 μs pulses were the most effective in combination with Lys and PLL for all microorganisms. Equivalent energy PEF bursts with a shorter duration of the pulse were less effective independently on PEF amplitude. Additionally, various treatment susceptibility patterns of microorganisms were determined and reported. In this study, the Gram-negative E. coli was the most treatment-resistant microorganism. Nevertheless, inactivation rates exceeding 2 log viability reduction were achieved for all analyzed yeast, fungi, and bacteria. This methodology could be used for drug-resistant microorganism’s new treatment development.

scholarly journals Sepsis in cancer patients residing in Zimbabwe: Spectrum of bacterial and fungal aetiologies and their antimicrobial susceptibility patterns.

2019 ◽  
Author(s):  
FRANK CHINOWAITA ◽  
Wendy Chaka ◽  
Tinashe K Nyazika ◽  
Tendai C Maboreke ◽  
Inam Chitsike ◽  
...  
Keyword(s):  
Blood Culture ◽  
Cancer Patients ◽  
Antimicrobial Susceptibility ◽  
Methicillin Resistance ◽  
Antimicrobial Treatment ◽  
Blood Cultures ◽  
Gram Negative ◽  
E Coli ◽  
Patients With Cancer ◽  
Susceptibility Patterns

Abstract Introduction: Cancer and sepsis comorbidity is a major public health problem in most parts of the world including Zimbabwe. The microbial aetiologies of sepsis and their antibiograms vary with time and locations. Knowledge on local microbial aetiologies of sepsis and their susceptibility patterns is critical in guiding empirical antimicrobial treatment choices. Methods: This was a descriptive cross sectional study which determined the microbial aetiologies of sepsis from blood cultures of paediatric and adult cancer patients obtained between July 2016 and June 2017. The TDR-X120 blood culture system and TDR 300B auto identification machine were used for incubation of blood culture bottles and identification plus antimicrobial susceptibility testing, respectively. Results: A total of 142 participants were enrolled; 50 (35.2%) had positive blood cultures with 56.0% gram positive, 42.0% gram negative bacteria and 2.0% yeast isolates. Most common isolates were Coagulase Negative Staphylococcus (CoNS) (22.0%), Escherichia coli (16.0%), Klebsiella pneumoniae (14.0%), Enterococcus faecalis (14.0%) and Staphylococcus aureus (8.0%) in all cancer patients. These isolates were similar in both haematological and solid cancers. Amikacin and meropenem showed 85.7% and 95.2% activity respectively against all gram negative isolates while vancomycin and linezolid were effective against 96.2% and 100.0% of all gram positive isolates respectively. Ten (66.7%) isolates of E. coli and K. pneumoniae were extended spectrum β-lactamase (ESBL) positive and the same proportion was observed on methicillin resistance among Staphylococcus species. Conclusions: The major microbial aetiologies of sepsis among patients with cancer in Zimbabwe were CoNS, E. coli, K. pneumoniae, E. faecalis and S. aureus. Most isolates were resistant to commonly used empirical antibiotics and there was high level of ESBL and methicillin resistance carriage. A nationwide survey on microbial aetiologies of sepsis and their susceptibility patterns would assist in the guidance of effective sepsis empiric antimicrobial treatment among patients with cancer.

E. coli electroeradication on a closed loop circuit by using milli-, micro- and nanosecond pulsed electric fields: Comparison between energy costs

2015 ◽  
Vol 103 ◽  
pp. 65-73 ◽  
Author(s):  
Alexis Guionet ◽  
Fabienne David ◽  
Clément Zaepffel ◽  
Mathilde Coustets ◽  
Karim Helmi ◽  
...  
Keyword(s):  
Electric Fields ◽  
Closed Loop ◽  
Pulsed Electric Fields ◽  
Energy Costs ◽  
E Coli ◽  
Nanosecond Pulsed Electric Fields

Effect of Growth Stage and Processing Temperature on the Inactivation of E. coli by Pulsed Electric Fields

1996 ◽  
Vol 59 (11) ◽  
pp. 1167-1171 ◽  
Author(s):  
USHA R. POTHAKAMURY ◽  
HUMBERTO VEGA ◽  
QINGHUA ZHANG ◽  
GUSTAVO V. BARBOSA-CANOVAS ◽  
BARRY G. SWANSON
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Growth Stage ◽  
Stationary Phases ◽  
Pulsed Electric Fields ◽  
Lag Phase ◽  
Logarithmic Phase ◽  
Processing Temperature ◽  
Square Wave ◽  
E Coli

The effect of growth stage and processing temperature on the inactivation of Escherichia coli subjected to pulsed electric fields was studied. Simulated milk ultrafiltrate (SMUF) inoculated with E. coli was subjected to high-intensity exponentially decaying or square-wave pulses with a field strength of 36 kV/cm and pulse duration of 2 μs at selected temperatures ranging between 3 and 40°C. The rate of inactivation increased with an increase in the processing temperature. Furthermore, square-wave pulses were more lethal than exponentially decaying pulses. At 7°C after 100 μs, square-wave pulses produced a 99% decrease while exponential decaying pulses produced a 93% decrease in bacterial cell population. Cells harvested at lag, log, and stationary phases were subjected to 2 and 4 pulses with an electric field intensity of 36 kV/cm at 7°C. Logarithmic-phase cells were more sensitive than stationary- and lag-phase cells to the pulsed electric field treatment.

scholarly journals The Literature Review of Electricity Effects on Cell Physiology and Related New Electrical Treatment Modalities

2019 ◽  
Author(s):  
Ertunc Simdi ◽  
Kader Ozcan
Keyword(s):  
Literature Review ◽  
Electric Fields ◽  
Cell Biology ◽  
Experimental Studies ◽  
Low Frequency ◽  
Pulsed Electric Fields ◽  
Treatment Modalities ◽  
Cell Physiology ◽  
Extremely Low Frequency ◽  
New Treatment

This paper is a mini literature review about electromagnetic field’s effects on cells, tissues and new treatment modalities. We have reviewed a papers which have been published in high quality journals in the last 5 years as two authors. This review’s aim is to be a resource for experimental studies about electricity’s effects on cell biology and pathophysiology. As a result of this literature review, we found that especially extremely low electric frequency and intermediate frequency fields have very important pathophysiological effects. We have mentioned four important expressions on this subject; electroporation, electrofusion, electrochemotherapy, gene electrotransference. Two different new treatment approaches have been developed by use of these two important electrical waves. First is tumor treating fields and the other is pulsed electric fields. Most studies in literature have been done with extremely low frequency and pulsed electric fields. In terms of diseases, most studies are about glioblastoma multiforme and malign melanoma.Most studies in literature have been done with extremely low frequency and pulsed electric fields. In terms of diseases, most studies are about glioblastoma and melanoma.

scholarly journals Sepsis in cancer patients residing in Zimbabwe: Spectrum of bacterial and fungal aetiologies and their antimicrobial susceptibility patterns.

2019 ◽  
Author(s):  
FRANK CHINOWAITA ◽  
Wendy Chaka ◽  
Tinashe K Nyazika ◽  
Tendai C Maboreke ◽  
Emmanuel Tizauone ◽  
...  
Keyword(s):  
Blood Culture ◽  
Cancer Patients ◽  
Antimicrobial Susceptibility ◽  
Antimicrobial Treatment ◽  
Blood Cultures ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Patients With Cancer ◽  
Susceptibility Patterns

Abstract Introduction: Cancer and sepsis comorbidity is a major public health problem in most parts of the world including Zimbabwe. The microbial aetiologies of sepsis and their antibiograms vary with time and locations. Knowledge on local microbial aetiologies of sepsis and their susceptibility patterns is critical in guiding empirical antimicrobial treatment choices. Methods: This was a descriptive cross sectional study which determined the microbial aetiologies of sepsis from blood cultures of paediatric and adult cancer patients obtained between July 2016 and June 2017. The TDR-X120 blood culture system and TDR 300B auto identification machine were used for incubation of blood culture bottles and identification plus antimicrobial susceptibility testing, respectively. Clinical and laboratory standards institute (CLSI) standard breakpoints were used to interpret the antimicrobial susceptibility results. Results: A total of 142 participants were enrolled; 50 (35.2%) had positive blood cultures with 56.0% Gram positive, 42.0% Gram negative bacteria and 2.0% yeast isolates. Most common isolates were coagulase negative Staphylococcus spp. (CoNS) (22.0%), Escherichia coli (16.0%), Klebsiella pneumoniae (14.0%), Enterococcus faecalis (14.0%) and Staphylococcus aureus (8.0%) in all cancer patients. These isolates were similar in both haematological and solid cancers. Gram negative isolates exhibited high resistance to gentamicin (61.9%) and ceftriaxone (71.4%) which are the empiric antimicrobial agents used in our setting. Amikacin and meropenem showed 85.7% and 95.2% activity respectively against all Gram negative isolates while vancomycin and linezolid were effective against 96.2% and 100.0% of all Gram positive isolates respectively. Ten (66.7%) isolates of E. coli and K. pneumoniae were extended spectrum β-lactamase (ESBL) positive. Among Staphylococcus species it was also observed that 10/15 (66.7%) of the isolates were methicillin resistan t. Conclusions : The major microbial aetiologies of sepsis among patients with cancer in Zimbabwe were CoNS, E. coli , K. pneumoniae , E. faecalis and S. aureus . Most isolates were resistant to commonly used empirical antibiotics and there was high level of ESBL and methicillin resistance carriage. A nationwide survey on microbial aetiologies of sepsis and their susceptibility patterns would assist in the guidance of effective sepsis empiric antimicrobial treatment among patients with cancer.

scholarly journals Inactivation of Escherichia coli and Staphylococcus aureus by Pulsed Electric Fields Increases with Higher Bacterial Population and with Agitation of Liquid Medium

2014 ◽  
Vol 77 (7) ◽  
pp. 1219-1223
Author(s):  
SILVIA BONETTA ◽  
SARA BONETTA ◽  
MONICA BELLERO ◽  
MARCO PIZZICHEMI ◽  
ELISABETTA CARRARO
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Electric Fields ◽  
Bacterial Population ◽  
Electric Pulse ◽  
Pulsed Electric Fields ◽  
Microbial Inactivation ◽  
Bacterial Inactivation ◽  
E Coli ◽  
And Staphylococcus Aureus

Inactivation of Escherichia coli, E. coli O157:H7, and Staphylococcus aureus in liquid media by pulsed electric fields (PEF) was conducted at varying bacterial populations with and without sample agitation. A laboratory-scale PEF batch unit with a rectangular electric pulse was used, operating under the following conditions: 25 kV/cm (E. coli, E. coli O157:H7) and 30 kV/cm (S. aureus) electric field strengths, 1-μs pulse width, 1-Hz pulse repetition rate, and 20 to 350 pulses for all samples. Not surprisingly, bacterial inactivation (for all three strains) increased with increasing pulse number, achieving the highest reduction at 350 pulses. Log CFU per milliliter microbial inactivation increased commensurately with increasing bacterial population (P < 0.05) but only when samples were treated with more than 200 pulses. For example, when E. coli was treated with 200 pulses at 105 CFU/ml, inactivation was only 3.0 Log versus 4.8 Log at the 1010 inoculation level. When E. coli O157:H7 was treated with 200 pulses at 105 CFU/ml, inactivation was only 2.5 Log versus 4.6 Log at the 1010 inoculation level. When S. aureus was treated with 200 pulses at 106 CFU/ml, inactivation was only 2.6 Log versus 4.8 Log at the 1010 inoculation level. Inactivation of populations was also found to be statistically greater (P < 0.05) when liquid samples were agitated, in comparison to nonagitated samples. Because PEF inactivation activity is influenced by bacterial population and sample agitation, future studies should carefully consider these factors in experimental designs and/or scaled-up industry application.

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