Bactericidal Properties of Ozone and Its Potential Application as a Terminal Disinfectant

2000 ◽  
Vol 63 (8) ◽  
pp. 1100-1106 ◽  
Author(s):  
GINNY MOORE ◽  
CHRIS GRIFFITH ◽  
ADRIAN PETERS

The efficacy of ozone as a terminal disinfectant was evaluated under laboratory conditions. Different microorganisms of importance to the food industry were inoculated onto stainless steel squares and incubated at various temperatures and relative humidities for up to 4 h. Survival of microorganisms from these controls was compared with identically incubated squares exposed to ozone. Exposure of the contaminated surfaces to ozone (2 ppm for 4 h) resulted in a reduction in microbial viability that ranged, depending on organism type, from 7.56 to 2.41 log values. For all the microorganisms tested, this loss in viability was significantly greater (P < 0.05) than that observed in the absence of ozone. Gram-negative bacteria were more sensitive to ozone than gram-positive organisms; bacteria were more sensitive than the yeast strain tested. Exposure to ozone (2 ppm for 4 h) in the presence of ultra-high temperature (UHT) milk resulted in a reduction in bacterial viability that ranged from 5.64 to 1.65 log values. In most cases, this reduction was significantly less (P < 0.05) than that achieved in the absence of organic material, although still significantly greater (P < 0.05) than that observed in the absence of ozone. The presence of a meat-based broth reduced the effectiveness of ozone to a greater extent, although the number of surviving gram-negative organisms was still significantly less (P < 0.05) than in the absence of ozone. Less than 1 log unit of yeast cells was destroyed when exposed to ozone in the presence of UHT milk or meat-based broth. Results of this investigation suggest that if applied after adequate cleaning ozone could be used as an effective disinfectant.

2009 ◽  
Vol 55 (5) ◽  
pp. 627-632 ◽  
Author(s):  
Thomas Candela ◽  
Marie Moya ◽  
Michel Haustant ◽  
Agnès Fouet

Poly-γ-glutamate has been described in many Gram-positive organisms. When anchored to the surface, it is a capsule and as such a virulence factor. Based on sequence similarities, few Gram-negative organisms have been suggested to synthesize poly-γ-glutamate. For the first time, a Gram-negative bacterium, Fusobacterium nucleatum , is shown to produce and secrete poly-γ-glutamate. Putative poly-γ-glutamate-synthesizing genes from Gram-negative organisms have been compared with their Gram-positive homologs by in silico analysis, i.e., gene sequence and phylogenetic analysis. Clusters of three instead of four genes were highlighted by our screen. The products of the first two genes display similarity with their Gram-positive equivalents, yet the sequences from the Gram-negative organisms can be distinguished from those of the Gram-positives. Interestingly, the sequence of the predicted product of the third gene is conserved among Gram-negative bacteria but displays no similarity to that of either the third or fourth gene of the Gram-positive operons. It is suggested that, like for Gram-positive bacteria, poly-γ-glutamate has a role in virulence for pathogens and one in survival for other Gram-negative bacteria.


2013 ◽  
Vol 12 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Javier Aragón-Sánchez ◽  
Benjamin A. Lipsky ◽  
Jose L. Lázaro-Martínez

Osteomyelitis frequently complicates infections in the feet of patients with diabetes. Gram-positive cocci, especially Staphylococcus aureus, are the most commonly isolated pathogens, but gram-negative bacteria also cause some cases of diabetic foot osteomyelitis (DFO). These gram-negatives require different antibiotic regimens than those commonly directed at gram-positives. There are, however, few data on factors related to their presence and how they influence the clinical picture. We conducted a retrospective study to determine the variables associated with the isolation of gram-negative bacteria from bone samples in cases of DFO and the clinical presentation of these infections. Among 341 cases of DFO, 150 had a gram-negative isolate (alone or combined with a gram-positive isolate) comprising 44.0% of all patients and 50.8% of those with a positive bone culture. Compared with gram-positive infections, wounds with gram-negative organisms more often had a fetid odor, necrotic tissue, signs of soft tissue infection accompanying osteomyelitis, and clinically severe infection. By multivariate analysis, the predictive variables related to an increased likelihood of isolating gram-negatives from bone samples were glycated hemoglobin <7% (odds ratio [OR] = 2.0, 95% confidence interval [CI] = 1.1-3.5) and a wound caused by traumatic injury (OR = 2.0, 95% CI = 1.0-3.9). Overall, patients whose bone samples contained gram-negatives had a statistically significantly higher prevalence of leukocytosis and higher white blood cell counts than those without gram-negatives. In conclusion, gram-negative organisms were isolated in nearly half of our cases of DFO and were associated with more severe infections, higher white blood cell counts, lower glycated hemoglobin levels, and wounds of traumatic etiology.


1984 ◽  
Vol 5 (11) ◽  
pp. 533-535 ◽  
Author(s):  
Karen M. Rafferty ◽  
Stephen J. Pancoast

AbstractIn an acute-care general hospital, 114 telephones, intercoms, dictaphones, and bedpan flusher handles were sampled in patient-care areas for type of bacterial contamination. Nine of these (7%) demonstrated potentially pathogenic bacteria including Klebsiella, Enterobacter, Pseudomonas and Aeromonas. Inanimate, environmental, staff hand-contact objects were only lightly contaminated, did not represent a significant reservoir of gram-negative organisms, and therefore, would be unlikely to be a vehicle of transmission of gram-negative bacteria from the hands of one staff member to another under routine circumstances. Surveillance and disinfection of telephones and related hand-contact items in the hospital appear unnecessary.


2013 ◽  
Vol 12 (04) ◽  
pp. 1350024 ◽  
Author(s):  
R. SELVAKUMAR ◽  
S. P. SURIYARAJ ◽  
V. JAYAVIGNESH ◽  
K. SWAMINATHAN

The present study involves the production of silver nanoparticles using a novel yeast strain Saccharomyces cerevisiae BU-MBT CY-1 isolated from coconut cell sap. The biological reduction of silver nitrate by the isolate was deducted at various time intervals. The yeast cells after biological silver reduction were harvested and subjected to carbonization at 400°C for 1 h and its properties were analyzed using Fourier transform infra-red spectroscopy, X-ray diffraction, scanning electron microscope attached with energy dispersive spectroscopy and transmission electron microscopy. The average size of the silver nanoparticles present on the surface of the carbonized silver containing yeast cells (CSY) was 19 ± 9 nm. The carbonized control yeast cells (CCY) did not contain any particles on its surface. The carbonized silver nanoparticles containing yeast cells (CSY) were made into bioactive emulsion and tested for its efficacy against various pathogenic Gram positive and Gram negative bacteria. The antimicrobial activity studies indicated that CSY bioactive nanoemulsion was effective against Gram negative organisms than Gram positive organism.


2018 ◽  
Vol 101 (5) ◽  
pp. 1593-1609 ◽  
Author(s):  
Benjamin Bastin ◽  
Patrick Bird ◽  
M Joseph Benzinger ◽  
Erin Crowley ◽  
James Agin ◽  
...  

Abstract The Bruker MALDI Biotyper® method utilizes matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS for the rapid and accurate identification and confirmation of Gram-negative bacteria from select media types. The alternative method was evaluated using nonselective and selective agars to identify Cronobacter spp., Salmonella spp., and select Gram-negative bacteria. Results obtained by the Bruker MALDI Biotyper were compared to the traditional biochemical methods as prescribed in the appropriate reference methods. Two collaborative studies were organized, one in the United States focusing on Cronobacter spp. and other Gram-negative bacteria, and one in Europe focusing on Salmonella spp. and other Gram-negative bacteria. Fourteen collaborators from seven laboratories located within the United States participated in the first collaborative study for Cronobacter spp. Fifteen collaborators from 15 service laboratories located within Europe participated in the second collaborative study for Salmonella spp. For each target organism (either Salmonella spp. or Cronobacter spp.), a total of 24 blind-coded isolates were evaluated. In each set of 24 organisms, there were 16 inclusivity organisms (Cronobacter spp. or Salmonella spp.) and 8 exclusivity organisms (closely related non-Cronobacter spp. and non-Salmonella spp. Gram-negative organisms). After testing was completed, the total percentage of correct identifications from each agar type for each strain was determined at a percentage of 100.0% to the genus level for the Cronobacter study and a percentage of 100.0% to the genus level for the Salmonella study. For both non-Cronobacter and non-Salmonella organisms, a percentage of 100.0% was correctly identified. The results indicated that the alternative method produced equivalent results when compared to the confirmatory procedures specified by each reference method.


2017 ◽  
Vol 13 ◽  
pp. 176-182
Author(s):  
Anastasia I. Piskaeva ◽  
Yuriy Yu. Sidorin ◽  
Alexander Yu. Prosekov

The aim of this study was to examine and compare bactericidal properties of silver nanoparticles on strains isolated from poultry processing plants wastes. Strains Еscherichia coli В-6240, Salmonella typhimurium В3533 were used as a model test strains for Gram-negative bacteria and Lactobacillus sp. B3730, Lactobacillus salivarius B5001, Thermoactinomyces thalpophilus AC936 were used as a model test strains for Gram-positive bacteria.


2021 ◽  
Vol 129 (5) ◽  
pp. 642
Author(s):  
В.М. Волынкин ◽  
Д.П. Данилович ◽  
С.К. Евстропьев ◽  
К.В. Дукельский ◽  
К.Ю. Сенчик ◽  
...  

Photoactive ZnO-SnO2-Ag(AgCl) nanomaterials have been prepared by polymer-salt method. Prepared materials able to generate singlet oxygen under UV and blue light irradiation. Materials structure and properties have been studied by optical and luminescence spectroscopy, XRD and SEM analysis. It was found that the structure of ZnO-SnO2-Ag(AgCl) materials consists of hexagonal ZnO, tetragonal SnO2, Ag and AgCl crystals having size 50÷60 nm. Obtained materials able to generate chemically active singlet oxygen under UV irradiation and have high bactericidal properties against both gram-positive and gram-negative bacteria. The increase of Ag content enhances the bactericidal properties of prepared materials.


PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0256556
Author(s):  
Abera Abdeta ◽  
Adane Bitew ◽  
Surafel Fentaw ◽  
Estifanos Tsige ◽  
Dawit Assefa ◽  
...  

Background Multidrug resistant, extremely drug-resistant, pan-drug resistant, carbapenem-resistant, and carbapenemase-producing gram-negative bacteria are becoming more common in health care settings and are posing a growing threat to public health. Objective The study was aimed to detect and phenotypically characterize carbapenem no- susceptible gram-negative bacilli at the Ethiopian Public Health Institute. Materials and methods A prospective cross-sectional study was conducted from June 30, 2019, to May 30, 2020, at the national reference laboratory of the Ethiopian Public Health Institute. Clinical samples were collected, inoculated, and incubated for each sample in accordance with standard protocol. Antimicrobial susceptibility testing was conducted using Kirby-Bauer disk diffusion method. Identification was done using the traditional biochemical method. Multidrug-resistant and extensively drug-resistant isolates were classified using a standardized definition established by the European Centre for Disease Prevention and Control and the United States Centers for Disease Prevention and Control. Gram-negative organisms with reduced susceptibility to carbapenem antibiotics were considered candidate carbapenemase producers and subjected to modified carbapenem inactivation and simplified carbapenem inactivation methods. Meropenem with EDTA was used to differentiate metallo-β-lactamase (MBL) from serine carbapenemase. Meropenem (MRP)/meropenem + phenylboronic acid (MBO) were used to differentiate Klebsiella pneumoniae carbapenemase (KPC) from other serine carbapenemase producing gram-negative organisms. Results A total of 1,337 clinical specimens were analyzed, of which 429 gram-negative bacterial isolates were recovered. Out of 429 isolates, 319, 74, and 36 were Enterobacterales, Acinetobacter species, and Pseudomonas aeruginosa respectively. In our study, the prevalence of multidrug-resistant, extensively drug-resistant, carbapenemase-producing, and carbapenem nonsusceptible gram-negative bacilli were 45.2%, 7.7%, 5.4%, and 15.4% respectively. Out of 429 isolates, 66 demonstrated reduced susceptibility to the antibiotics meropenem and imipenem. These isolates were tested for carbapenemase production of which 34.8% (23/66) were carbapenemase producers. Out of 23 carbapenemase positive gram-negative bacteria, ten (10) and thirteen (13) were metallo-beta-lactamase and serine carbapenemase respectively. Three of 13 serine carbapenemase positive organisms were Klebsiella pneumoniae carbapenemase. Conclusion This study revealed an alarming level of antimicrobial resistance (AMR), with a high prevalence of multidrug-resistant (MDR) and extremely drug-resistant, carbapenemase-producing gram-negative bacteria, particularly among intensive care unit patients at the health facility level. These findings point to a scenario in which clinical management of infected patients becomes increasingly difficult and necessitates the use of “last-resort” antimicrobials likely exacerbating the magnitude of the global AMR crisis. This mandates robust AMR monitoring and an infection prevention and control program.


Author(s):  
Philippa C. Matthews

This chapter consists of short notes, diagrams, and tables to summarize Gram-negative organisms that are significant causes of disease in the tropics and subtropics. This includes Escherichia coli, Shigella, and Salmonella species (including typhoid and paratyphoid), Brucella, melioid, Campylobacter, and meningococci. For ease of reference, each topic is broken down into sections, including classification, epidemiology, microbiology, pathophysiology, clinical syndromes, diagnosis, treatment, and prevention.


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