scholarly journals Studies on the disinfection efficiency of hoa sen medical instrument sterilizing equipment at the general, obstetrics and paediatrics hospitals in TraVinh Province

2019 ◽  
Vol 41 (3) ◽  
Author(s):  
Pham Hoang Long ◽  
Nguyen Hoai Chau ◽  
Nguyen Chi Thanh ◽  
Ngo Quoc Buu
Keyword(s):  
Cell Membrane ◽  
Removal Efficiency ◽  
Medical Instrument ◽  
Culture Method ◽  
Aerobic Bacteria ◽  
Bacterial Cells ◽  
E Coli ◽  
Before And After ◽  
Microbiological Criteria ◽  
Bacterial Cell Membrane

This research aims to study on the disinfection efficiency of Hoa Sen medical instrument sterilizing equipment based on the application of ECA technology at General Hospital and Obstetrics and Paediatrics Hospitals in Tra Vinh. Disinfection using ECA technology is a method that does not require the introduction of special oxidizing agents except of water and salt. ECA solution - Anolyte solution has very strong oxidants, which oxidize components such as protein, lipid, etc. (usually of the bacterial cell membrane) that make the cell membrane decomposed, reducing 77−93% of the respiratory ability of bacterial cells, weakening them and eventually being destroyed. Hoa Sen medical instrument sterilizing equipment has a similar construction form as a regular double washing table with two wash basins, wherein one sink with a faucet which produces purified water, while other one has a faucet that gives anolyte solution for sterilization. Both faucets are based on a touch support. At the bottom of the sink an anolyte solution production system was installed. Valorization of the disinfection ability of the Hoa Sen medical instrument sterilizing equipment was based on the determination of the number of microorganisms on the surface of the instrument before and after being soaked with an antiseptic washing table. Microbiological criteria are the number of aerobic bacteria, E. Coli and Coliforms. Analytical samples were quantified by culture method on agar plates. Analysis of total aerobic bacteria, E. Coli and Coliforms bacteria according to Vietnam Standard TCVN 4884:2015, TCVN 6846:2007 and TCVN 6848:2007, respectively. The results showed that bacterial removal efficiency was elevated with a novel Hoa Sen sterilizing equipment anolyte. In laboratory scale, E. Coli and Coliforms bacteria with a density of 105 CFU/mL were completely removed in 30 sec contact with an anolyte solution of 300 mg/L active chlorine concentration. In hospital scale, the removal efficiency of total aerobic bacteria on the surface of medical instruments after surgery was 99% for one minute disinfection time. For E. Coli and Coliforms bacteria, the results of the analysis were not detected in both cases before and after sterilization. 

scholarly journals Studies on the disinfection efficiency of hoa sen medical instrument sterilizing equipment at the general, obstetrics and paediatrics hospitals in TraVinh Province

2019 ◽  
Vol 41 (3) ◽  
Author(s):  
Pham Hoang Long ◽  
Nguyen Hoai Chau ◽  
Nguyen Chi Thanh ◽  
Ngo Quoc Buu
Keyword(s):  
Cell Membrane ◽  
Removal Efficiency ◽  
Medical Instrument ◽  
Culture Method ◽  
Aerobic Bacteria ◽  
Bacterial Cells ◽  
E Coli ◽  
Before And After ◽  
Microbiological Criteria ◽  
Bacterial Cell Membrane

This research aims to study on the disinfection efficiency of Hoa Sen medical instrument sterilizing equipment based on the application of ECA technology at General Hospital and Obstetrics and Paediatrics Hospitals in Tra Vinh. Disinfection using ECA technology is a method that does not require the introduction of special oxidizing agents except of water and salt. ECA solution - Anolyte solution has very strong oxidants, which oxidize components such as protein, lipid, etc. (usually of the bacterial cell membrane) that make the cell membrane decomposed, reducing 77−93% of the respiratory ability of bacterial cells, weakening them and eventually being destroyed. Hoa Sen medical instrument sterilizing equipment has a similar construction form as a regular double washing table with two wash basins, wherein one sink with a faucet which produces purified water, while other one has a faucet that gives anolyte solution for sterilization. Both faucets are based on a touch support. At the bottom of the sink an anolyte solution production system was installed. Valorization of the disinfection ability of the Hoa Sen medical instrument sterilizing equipment was based on the determination of the number of microorganisms on the surface of the instrument before and after being soaked with an antiseptic washing table. Microbiological criteria are the number of aerobic bacteria, E. Coli and Coliforms. Analytical samples were quantified by culture method on agar plates. Analysis of total aerobic bacteria, E. Coli and Coliforms bacteria according to Vietnam Standard TCVN 4884:2015, TCVN 6846:2007 and TCVN 6848:2007, respectively. The results showed that bacterial removal efficiency was elevated with a novel Hoa Sen sterilizing equipment anolyte. In laboratory scale, E. Coli and Coliforms bacteria with a density of 105 CFU/mL were completely removed in 30 sec contact with an anolyte solution of 300 mg/L active chlorine concentration. In hospital scale, the removal efficiency of total aerobic bacteria on the surface of medical instruments after surgery was 99% for one minute disinfection time. For E. Coli and Coliforms bacteria, the results of the analysis were not detected in both cases before and after sterilization. 

Synthesis and structure-activity study of quaternary ammonium functionalized β-cyclodextrin-carboxymethylcellulose polymers

2011 ◽  
Vol 63 (12) ◽  
pp. 2827-2832 ◽  
Author(s):  
Danielle Bonenfant ◽  
François-René Bourgeois ◽  
Murielle Mimeault ◽  
Frédéric Monette ◽  
Patrick Niquette ◽  
...  
Keyword(s):  
Quaternary Ammonium ◽  
Antimicrobial Activities ◽  
Bacterial Cells ◽  
Experimental Conditions ◽  
E Coli ◽  
Antimicrobial Efficiency ◽  
Disinfection Process ◽  
Didecyldimethylammonium Chloride ◽  
Low Toxicity ◽  
Bacterial Cell Membrane

Carboxymethylcellulose (CMC) and β-cyclodextrin (β-CD)-based polymers functionalized with two types of quaternary ammonium compounds (QACs), the alkaquat DMB-451 (N-alkyl (50% C14, 40% C12, 10% C10) dimethylbenzylammonium chloride) (DMD-451) named polymer DMB-451, and FMB 1210-8 (a blend of 32 w% N-alkyl (50% C14, 40% C12, 10% C10) dimethylbenzylammonium chloride and 48 w% of didecyldimethylammonium chloride) named polymer FMB 1210-8, were synthethized and characterized by Fourier transform infrared spectroscopy. The antimicrobial activities of these polymers against Eschericia coli were also evaluated at 25 °C in wastewater. The results have indicated that the polymer FMB 1210-8 possesses a high-affinity binding with bacterial cells that induces a rapid disinfection process. Moreover, in the same experimental conditions of disinfection (mixture of 1.0 g of polymer and 100 mL of wastewater), the polymer FMB 1210-8 has a higher antimicrobial efficiency (99.90%) than polymer DMB-451 (92.8%). This phenomenon might be associated to a stronger interaction with bacterial cells due to stronger binding affinity for E. coli cells and greater killing efficiency of the C10 alkyl chains QAC of polymer FMB 1210-8 to disrupt the bacterial cell membrane as compared to N-alkyl (50% C14, 40% C12, 10% C10) dimethylbenzylammonium chloride. Together, these results suggest that the polymer FMB 1210-8 could constitute a good disinfectant against Escherichia coli, which could be advantageously used in wastewater treatments due to the low toxicity of β-CD and CMC, and moderated toxicity of FMB 1210-8 to human and environment.

Presence of Bacterial Pathogens and Levels of Indicator Bacteria Associated with Duck Carcasses in a Commercial Processing Facility

2020 ◽  
Vol 83 (4) ◽  
pp. 605-608
Author(s):  
M. E. BERRANG ◽  
R. J. MEINERSMANN ◽  
S. W. KNAPP
Keyword(s):  
Meat Products ◽  
Aerobic Bacteria ◽  
E Coli ◽  
Before And After ◽  
Processing Line ◽  
Commercial Processing ◽  
Processing Techniques ◽  
Sampling Times ◽  
Live Bird ◽  
Microbiological Aspects

ABSTRACT Little information has been published on the microbiological aspects of U.S. commercial duck processing. The objective of this study was to measure prevalence and/or levels of bacteria in duck samples representing the live bird and partially or fully processed oven-ready duck meat. At 12 monthly sampling times, samples were collected at six sites along the processing line in a commercial duck slaughter plant. Crop and cecum samples were collected at the point of evisceration. Whole carcass rinse samples were collected before and after carcass immersion chilling plus application of an antimicrobial spray. Leg quarters were collected from the cut-up line before and after application of an antimicrobial dip treatment. All samples (five from each site per monthly replication) were directly plated and/or enriched for Salmonella and Campylobacter. For the last 10 replications, carcass and leg quarter rinse samples were also evaluated for enumeration of total aerobic bacteria, Escherichia coli, and coliforms. Most cecum, crop, and prechill carcass rinse samples were positive for Campylobacter (80, 72, and 67%, respectively). Carcass chilling and chlorinated spray significantly lowered Campylobacter prevalence (P < 0.01), and even fewer leg quarters were positive for Campylobacter (P < 0.01). Passage through a chlorinated dip did not further reduce Campylobacter prevalence on leg quarters. Salmonella was infrequently found in any of the samples examined (≤10%). Total aerobic bacteria, coliforms, and E. coli levels were reduced (P < 0.01) on whole carcasses by chilling but were not different after cut-up or leg quarter dip treatment. Overall, current commercial duck processing techniques as applied in the tested plant were effective for reducing the prevalence and levels of Campylobacter on duck meat products. HIGHLIGHTS

scholarly journals Shape Changes and Interaction Mechanism of Escherichia coli Cells Treated with Sericin and Use of a Sericin-Based Hydrogel for Wound Healing

2016 ◽  
Vol 82 (15) ◽  
pp. 4663-4672 ◽  
Author(s):  
Rui Xue ◽  
Yalong Liu ◽  
Qingsong Zhang ◽  
Congcong Liang ◽  
Huazhen Qin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Cell Membrane ◽  
Interaction Mechanism ◽  
Bacterial Cells ◽  
Content Type ◽  
E Coli ◽  
Membrane Blebbing ◽  
Sterile Gauze

ABSTRACTTo verify the interaction mechanism between sericin andEscherichia coli, especially the morphological and structural changes in the bacterial cells, the antimicrobial activity of sericin againstE. colias a model for Gram-negative bacteria was investigated. The antibacterial activity of sericin onE. coliand the interaction mechanism were investigated in this study by analyzing the growth, integrity, and morphology of the bacterial cells following treatment with sericin. The changes in morphology and cellular compositions of bacterial cells treated with sericin were observed by an inverted fluorescence microscope, scanning electron microscopy, and transmission electron microscopy. Changes in electrical conductivity, total sugar concentration of the broth for the bacteria, and protein expression of the bacteria were determined to investigate the permeability of the cell membrane. A sericin-based hydrogel was prepared for anin vivostudy of wound dressing. The results showed that the antibacterial activity of the hydrogel increased with the increase in the concentration of sericin from 10 g/liter to 40 g/liter. The introduction of sericin induces membrane blebbing ofE. colicells caused by antibiotic action on the cell membrane. The cytoplasm shrinkage phenomenon was accompanied by blurring of the membrane wall boundaries. WhenE. colicells were treated with sericin, release of intracellular components quickly increased. The electrical conductivity assay indicated that the charged ions are reduced after exposure to sericin so that the integrity of the cell membrane is weakened and metabolism is blocked. In addition, sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated that sericin hinders the expression of bacterial protein. Sericin may damage the integrity of the bacterial cell membrane, thereby eventually inhibiting the growth and reproduction ofE. coli. Compared to sterile gauze, the sericin-based hydrogel promoted fibroblast cell proliferation and accelerated the formation of granulation tissues and neovessels.IMPORTANCEThe specific relationship and interaction mechanism between sericin andE. colicells were investigated and elucidated. The results show that after 12 h of treatment, sericin molecules induce membrane blebbing ofE. colicells, and the bacteria show decreases in liquidity and permeability of biological membrane, resulting in alterations in the conductivity of the culture medium and the integrity of the outer membrane. The subsequentin vivoresults demonstrate that the sericin-poly(N-isopropylacrylamide-N,N′-methylene-bis-acrylamide [NIPAm-MBA]) hydrogel accelerated wound healing compared to that with sterile gauze, which is a beneficial result for future applications in clinical medicine and the textile, food, and coating industries.

Microbiological Testing of Raw, Boxed Beef in the Context of Hazard Analysis Critical Control Point at a High-Line-Speed Abattoir

2000 ◽  
Vol 63 (12) ◽  
pp. 1681-1686 ◽  
Author(s):  
K. W. F. JERICHO ◽  
G. C. KOZUB ◽  
V. P. J. GANNON ◽  
C. M. TAYLOR
Keyword(s):  
Cold Storage ◽  
Hazard Analysis ◽  
Control Point ◽  
Aerobic Bacteria ◽  
Cooling Process ◽  
E Coli ◽  
Critical Control Point ◽  
Line Speed ◽  
High Line ◽  
Before And After

The efficacy of cold storage of raw, bagged, boxed beef was assessed microbiologically at a high-line-speed abattoir (270 carcasses per h). At the time of this study, plant management was in the process of creating a hazard analysis critical control point plan for all processes. Aerobic bacteria, coliforms, and type 1 Escherichia coli were enumerated (5 by 5-cm excision samples, hydrophobic grid membrane filter technology) before and after cold storage of this final product produced at six fabrication tables. In addition, the temperature-function integration technique (TFIT) was used to calculate the potential number of generations of E. coli during the first 24 or 48 h of storage of the boxed beef. Based on the temperature histories (total of 60 boxes, resulting from 12 product cuts, five boxes from each of two fabrication tables on each of 6 sampling days, and six types of fabrication tables), TFIT did not predict any growth of E. coli (with or without lag) for the test period. This was verified by E. coli mean log10 values of 0.65 to 0.42 cm2 (P > 0.05) determined by culture before and after the cooling process, respectively. Counts of aerobic bacteria and coliforms were significantly reduced (P < 0.001 and P < 0.05, respectively) during the initial period of the cooling process. There were significant microbiological differences (P < 0.05) between table-cut units.

Decontaminating Beef for Escherichia coliO157:H7

1998 ◽  
Vol 61 (5) ◽  
pp. 547-550 ◽  
Author(s):  
IVONE DELAZARI ◽  
SEBASTIÃO TIMO IARIA ◽  
HANS P. RIEMANN ◽  
DEAN O. CLIVER ◽  
THEODORE MORI
Keyword(s):  
Opposite Effect ◽  
Tap Water ◽  
Escherichia Coli O157 ◽  
Bacterial Cells ◽  
Connective Tissues ◽  
Lean Tissue ◽  
E Coli ◽  
Significant Difference ◽  
Before And After ◽  
Control Samples

Beef lean, fat, and connective tissues were inoculated with Escherichia coli O157:H7 before and after a prewashing procedure to compare the efficacy of prewashing and no prewashing on bacterial adherence and, consequently, on the removal of bacteria from the inoculated surfaces. Prewashing consisted of spraying tissues with tap water before inoculation. Final washing with disinfectant solutions compared the efficacy of several chemicals for the removal or destruction of E. coli O157:H7. The results showed that prewashing was very effective in reducing the numbers of bacterial cells on beef tissues, mainly lean tissue, in the control samples which received final washing with water. An opposite effect of prewashing was observed when disinfectant Solutions were used for final washing; this may be due to dilution by water carried on the tissues after prewashing. The efficacy of Chemicals was dependent on the type of exposed tissue. Hydrogen peroxide (3%) was more efficient in the removal of E. coli O157:H7 from connective tissues, with reductions greater than 4 log CFU/cm2, compared to a normally washed control (P < 0.01). Chlorhexidine (0.1%) was very efficient on fat and lean tissues, causing reductions over 5 log CFU/cm2 on not prewashed fat and lean tissues, compared to the control (P < 0.01). Acetic acid (5%) was the least effective, decreasing the number of CFU by under 1 log/cm2 as compared to the control; and no statistically significant difference was found among tissues, even though the removal of bacteria seemed less in lean tissue compared to fat or connective tissues.

scholarly journals AFM Study of Nanoscale Membrane Perturbation Induced by Antimicrobial Lipopeptide C14 KYR

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 495
Author(s):  
Sawinee Nasompag ◽  
Pawinee Siritongsuk ◽  
Saengrawee Thammawithan ◽  
Oranee Srichaiyapol ◽  
Panchika Prangkio ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Membrane Separation ◽  
Adhesion Force ◽  
Bacterial Cells ◽  
Average Roughness ◽  
E Coli ◽  
Topographic Features ◽  
Membrane Perturbation ◽  
Afm Imaging ◽  
Before And After

Lipopeptides have been extensively studied as potential antimicrobial agents. In this study, we focused on the C14-KYR lipopeptide, a modified version of the KYR tripeptide with myristic acid at the N-terminus. Here, membrane perturbation of live E. coli treated with the parent KYR and C14-KYR peptides was compared at the nanoscale level using AFM imaging. AFM analyses, including average cellular roughness and force spectroscopy, revealed the severe surface disruption mechanism of C14-KYR. A loss of surface roughness and changes in topographic features included membrane shrinkage, periplasmic membrane separation from the cell wall, and cytosolic leakage. Additional evidence from synchrotron radiation FTIR microspectroscopy (SR-FTIR) revealed a marked structural change in the membrane component after lipopeptide attack. The average roughness of the E. coli cell before and after treatment with C14-KYR was 129.2 ± 51.4 and 223.5 ± 14.1 nm, respectively. The average rupture force of the cell treated with C14-KYR was 0.16 nN, four times higher than that of the untreated cell. Our study demonstrates that the mechanistic effect of the lipopeptide against bacterial cells can be quantified through surface imaging and adhesion force using AFM.

scholarly journals Influence of Aerobic Bacteria Concentration on the Process of its Survival in the Presence of Oxygen

2020 ◽  
Keyword(s):  
Unit Volume ◽  
Aqueous Media ◽  
Oxygen Atmosphere ◽  
Aerobic Bacteria ◽  
Bacterial Cells ◽  
High Concentration ◽  
Aquatic Medium ◽  
Subsequent Decrease ◽  
Before And After ◽  
Number Of Microorganisms

Purpose of the study is to study the viability of aerobic microorganisms in an oxygen atmosphere with different initial content in the aquatic medium. Compare the effect of gas on different concentrations of bacteria per unit volume of the water. Methods. Aerobic bacteria of the genus Bacillus cereus bacteria type were the studied microorganisms. Model aqueous media were created on the basis of distilled deaerated water with the addition of bacteria of a particular type. Oxygen was bubbled into the microbial water throughout the process at a rate of 0.2 cm3/s. The duration of the study was 2 hours, during which the total gas consumption corresponded to 1.4 dm3. The number of microorganisms (NM) before and after the experiments was determined by counting the colonies that grew on the Petri dishes. Results. A two-stage process of oxygen exposure to aerobic bacteria was detected - accumulation and reduction of its number per unit volume of water during all experiments. At the first stage of the process, there was an increase of NM during 1800-3600 s with its subsequent decrease (II stage). With an increase in the microbial load in the water from 102 to 104 CFU/cm3, the duration of the process of bacterial accumulation was decreased in two times. An active reproduction of bacterial cells was investigated at the low concentration of bacteria in the water, and its active reduction - at the high concentration that is explained by cells destruction under conditions of constant supply of oxygen of the established rate. Conclusions. The oxygen influence on the change of the number of aerobic microorganisms in the aquatic medium is explained. It is investigated that the oxygen action on bacteria in the water divides the process of its viability into two stages: accumulation (I stage) and reduction of its number (II stage). It is shown that the duration of the process of bacteria accumulation in the oxygen atmosphere depends on its initial amount in the water, namely with increasing of the initial NM per unit volume of the water, the duration of the stage of microorganisms accumulation decreases significantly.

scholarly journals Specific Electromagnetic Effects of Microwave Radiation on Escherichia coli

2011 ◽  
Vol 77 (9) ◽  
pp. 3017-3022 ◽  
Author(s):  
Yury Shamis ◽  
Alex Taube ◽  
Natasa Mitik-Dineva ◽  
Rodney Croft ◽  
Russell J. Crawford ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cell Membrane ◽  
Cell Morphology ◽  
Laser Scanning ◽  
Simulation Software ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Bacterial Cells ◽  
Content Type ◽  
E Coli

ABSTRACTThe present study investigated the effects of microwave (MW) radiation applied under a sublethal temperature onEscherichia coli. The experiments were conducted at a frequency of 18 GHz and at a temperature below 40°C to avoid the thermal degradation of bacterial cells during exposure. The absorbed power was calculated to be 1,500 kW/m3, and the electric field was determined to be 300 V/m. Both values were theoretically confirmed using CST Microwave Studio 3D Electromagnetic Simulation Software. As a negative control,E. colicells were also thermally heated to temperatures up to 40°C using Peltier plate heating. Scanning electron microscopy (SEM) analysis performed immediately after MW exposure revealed that theE. colicells exhibited a cell morphology significantly different from that of the negative controls. This MW effect, however, appeared to be temporary, as following a further 10-min elapsed period, the cell morphology appeared to revert to a state that was identical to that of the untreated controls. Confocal laser scanning microscopy (CLSM) revealed that fluorescein isothiocyanate (FITC)-conjugated dextran (150 kDa) was taken up by the MW-treated cells, suggesting that pores had formed within the cell membrane. Cell viability experiments revealed that the MW treatment was not bactericidal, since 88% of the cells were recovered after radiation. It is proposed that one of the effects of exposingE. colicells to MW radiation under sublethal temperature conditions is that the cell surface undergoes a modification that is electrokinetic in nature, resulting in a reversible MW-induced poration of the cell membrane.

Note: Ultra High Hydrostatic Pressure Inactivation of Escherichia Coli in Milk, and Orange and Peach Juices

2003 ◽  
Vol 9 (6) ◽  
pp. 403-407 ◽  
Author(s):  
C. Dogan ◽  
O. Erkmen
Keyword(s):  
Escherichia Coli ◽  
Hydrostatic Pressure ◽  
Cell Growth ◽  
Orange Juice ◽  
High Hydrostatic Pressure ◽  
Raw Milk ◽  
Aerobic Bacteria ◽  
Bacterial Cells ◽  
E Coli ◽  
Peach Juice

Inactivation of Escherichia coli by high hydrostatic pressure (UHHP) was determined in broth, milk and orange and peach juices inoculated with the bacteria. HHP ranged from 200 to 700 MPa at 25 C and different treatment times. No cell growth occurred in broth after 60, 25, 15, 10 and 7 min at 300, 400, 500, 600 and 700 MPa, respectively. Reduction of aerobic bacteria in milk and peach juice were 3.08 and 6.07 log units after 15 min at 400 MPa, respectively, while all bacterial cells were inactivated in orange juice. Sterilisation of raw milk contaminated with E. coli occurred at 600 MPa for 30 min, while peach and orange juices needed 12 and 10 min, respectively. The injury of cells in broth at 300 MPa ranged from 8.8 to 100% depending on magnitude of pressure and treated time. In general, inactivation of aerobic bacteria and E. coli was enhanced significantly (P<0.01) by increasing the pressure.

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