Removal of pathogenic bacterial biofilms by combinations of oxidizing compounds

2015 ◽  
Vol 61 (5) ◽  
pp. 351-356 ◽  
Author(s):  
Gabriela María Olmedo ◽  
Mariana Grillo-Puertas ◽  
Luciana Cerioni ◽  
Viviana Andrea Rapisarda ◽  
Sabrina Inés Volentini

Bacterial biofilms are commonly formed on medical devices and food processing surfaces. The antimicrobials used have limited efficacy against the biofilms; therefore, new strategies to prevent and remove these structures are needed. Here, the effectiveness of brief oxidative treatments, based on the combination of sodium hypochlorite (NaClO) and hydrogen peroxide (H2O2) in the presence of copper sulfate (CuSO4),were evaluated against bacterial laboratory strains and clinical isolates, both in planktonic and biofilm states. Simultaneous application of oxidants synergistically inactivated planktonic cells and prevented biofilm formation of laboratory Escherichia coli, Salmonella enterica serovar Typhimurium, Klebsiella pneumoniae, and Staphylococcus aureus strains, as well as clinical isolates of Salmonella enterica subsp. enterica, Klebsiella oxytoca, and uropathogenic E. coli. In addition, preformed biofilms of E. coli C, Salmonella Typhimurium, K. pneumoniae, and Salmonella enterica exposed to treatments were removed by applying 12 mg/L NaClO, 0.1 mmol/L CuSO4, and 350 mmol/L H2O2for 5 min. Klebsiella oxytoca and Staphylococcus aureus required a 5-fold increase in NaClO concentration, and the E. coli clinical isolate remained unremovable unless treatments were applied on biofilms formed within 24 h instead of 48 h. The application of treatments that last a few minutes using oxidizing compounds at low concentrations represents an interesting disinfection strategy against pathogens associated with medical and industrial settings.

2017 ◽  
Vol 82 (4) ◽  
pp. 367-377 ◽  
Author(s):  
Demet Coskun ◽  
Seher Gur ◽  
Mehmet Coskun

The aim of this study was the preparation of 1,1?-(2,5-thiophenediyl) bis[1-(2-benzofuranyl)methanone] (2), the corresponding diketoxime (3), and the ether and ester derivatives (4a?e) of the diketoxime. These compounds were prepared in good yields. Minimum inhibitory concentrations (MIC) of the synthesized compounds 1?4 were determined against Salmonella enterica subsp. enterica serovar Typhimurium, Escherichia coli and Staphylococcus aureus. Among the synthesized compounds, 1 and 4e showed good activity against E. coli, S. enterica and S. aureus.


Antibiotics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 51 ◽  
Author(s):  
Natalie Gugala ◽  
Dennis Vu ◽  
Michael D. Parkins ◽  
Raymond J. Turner

In response to the occurrence of antibiotic resistance, there has been rapid developments in the field of metal-based antimicrobials. Although it is largely assumed that metals provide broad-spectrum microbial efficacy, studies have shown that this is not always the case. Therefore, in this study, we compared the susceptibilities of 93 clinical isolates belonging to the species Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus against six metals, namely aluminum, copper, gallium, nickel, silver and zinc. To provide qualitative comparative information, the resulting zones of growth inhibition were compared to the minimal inhibitory concentrations of three indicator strains E. coli ATCC 25922, P. aeruginosa ATCC 27853 and S. aureus ATCC 25923. Here, we demonstrate that the metal efficacies were species- and isolate-specific. Only several isolates were either resistant or sensitive to all of the six metals, with great variability found between isolates. However, the greatest degree of similarity was found with the E. coli isolates. In contrast, the susceptibilities of the remaining two collections, S. aureus and P. aeruginosa, were more highly dispersed. Using this information, we have shown that metals are not equal in their efficacies. Hence, their use should be tailored against a particular microorganism and care should be taken to ensure the use of the correct concentration.


2006 ◽  
Vol 50 (2) ◽  
pp. 607-617 ◽  
Author(s):  
Charlotte Verdet ◽  
Yahia Benzerara ◽  
Valérie Gautier ◽  
Olivier Adam ◽  
Zahia Ould-Hocine ◽  
...  

ABSTRACT Eleven Klebsiella pneumoniae clinical isolates and one Klebsiella oxytoca clinical isolate showing various pulsed-field gel electrophoresis types and producing an inducible DHA-1 class C β-lactamase were isolated in the Parisian region between 1998 and 2003. The aim of this study was to compare the genetic organization of the bla DHA-1 genes in this collection of clinical isolates. In four isolates, the Morganella morganii-derived genomic region containing bla DHA-1 was inserted in an entire complex sul1-type integron, including a region common to In6-In7 (CR1), as previously described in a bla DHA-1-producing Salmonella enterica serovar Enteritidis KF92 isolate from Saudi Arabia in 1992. Different gene cassette arrays were characterized in each of these integrons. In two of them, an additional 10-kb fragment was inserted between the CR1 and the M. morganii-derived region and was similar to the sap (ABC transporter family) and psp (phage shock protein) operons originated from Salmonella enterica serovar Typhimurium. The length of the M. morganii region was variable, suggesting that several independent recombination events have occurred and that open reading frame orf513 encodes a recombinase involved in the mobilization of the resistance genes. The genetic organization of bla DHA-1 was identical in the eight other isolates. This structure is likely derived from a complex integron following the insertion of IS26, leading to the deletion of the first part of integron. The horizontal transfer of one plasmid carrying that truncated integron was shown for seven of these isolates.


Author(s):  
N. P. Akani ◽  
J. O. Williams ◽  
A. U. Nnamdi

Aims: To compare the antimicrobial potential of branded and unbranded disinfectants on clinical bacterial isolates. Study Design: The agar-well diffusion and micro broth dilution were adopted for the study. Ten disinfectants of which five were branded (industrial prepared) and five unbranded (indigenous prepared) were used against E. coli and Staphylococcus aureus. Place and Duration of Study: Department of Microbiology, Rivers State University. the study was for a period of two months (June-July, 2018). Methodology: Faecal samples were collected from the University Medical centre and were analyzed in the Microbiology Laboratory for the isolation of Escherichia coli and Staphylococcus aureus using standard microbiological method. The antimicrobial potential of both branded and unbranded disinfectants on the clinical isolates were evaluated using the micro dilution technique and the well in agar technique. Results: The result in this study showed that both branded and unbranded disinfectants were effective on the E. coli and Staphylococcus isolates. However, the unbranded were only effective at high concentrations. E. coli had zone of inhibition ranging from 0 to 22 mm when tested with the unbranded disinfectant, while 0 to 17 mm was recorded for Staphylococcus aureus. The zones of inhibition of the branded disinfectant on E. coli ranged from 0 to 27 mm, while zone diameter of Staphylococcus aureus ranged from 0 to 25 mm. Among the unbranded disinfectants, Lysol produced the highest zone of inhibition While among the branded disinfectants, Savlon produced the highest zone of inhibition. The positive control was effective against all tested organisms with zones of inhibition ranging from 9-28 mm. On the other hand, as expected, the negative control (sterile distilled water) did not show any zone of inhibition. Conclusion: The study showed that branded disinfectants were more effective on the clinical isolates than the unbranded disinfectants.


2010 ◽  
Vol 73 (7) ◽  
pp. 1247-1256 ◽  
Author(s):  
STACEY COLLIGNON ◽  
LISE KORSTEN

The ability of the foodborne pathogens Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica subsp. enterica serovar Typhimurium, and Staphylococcus aureus to attach, colonize, and survive on stone fruit surfaces was investigated. Fifty microliters of bacterial suspension was spot inoculated onto the sterile intact fructoplane of whole peaches and plums. Minimum time required for initial adhesion and attachment was recorded for different surface contact times. Surface colonization patterns of the four pathogens and survival under simulated commercial export conditions also were evaluated. L. monocytogenes and Salmonella Typhimurium attached immediately to stone fruit surfaces. E. coli O157:H7 and S. aureus were visibly attached after 30 s and 1 h, respectively, of direct exposure. Holding freshly harvested stone fruit at 0.5°C to simulate cold storage conditions significantly lowered the titer of E. coli O157:H7 on plums and the titers of L. monocytogenes and Salmonella Typhimurium on stone fruit. E. coli O157:H7 and L. monocytogenes at a low inoculum level and S. aureus and Salmonella Typhimurium at high and low levels did not survive the simulated export chain conditions at titers that exceeded the minimum infectious dose. However, E. coli O157:H7 and L. monocytogenes were able to survive on stone fruit surfaces when inoculated at an artificially high level. In this case, the final titer at the end of the supply chain was higher than the infectious dose. In this laboratory experiment, E. coli O157:H7, L. monocytogenes, Salmonella Typhimurium, and S. aureus at potential natural contamination levels were unable to survive simulated export conditions.


Author(s):  
М. S. Saypullaev ◽  
А. U. Koychuev ◽  
Т. B. Mirzoeva

The successful conduct of disinfection measures largely depends on the availability of veterinary practice a highly efficient, environmentally safe disinfectants. In this regard, finding new highly efficient disinfectant remains relevant. Studies found that the "Polied" (OOO "Razvitie XXI Vek, Russia) can be attributed to the highly efficient and environmentally friendly means. Solutions "Polied" have a high disinfectant activity against smooth and rough surfaces in the laboratory against gram-positive, gram-negative bacteria, mycobacteria and spores of microorganisms. Studies have established that solutions should be "Polied" obezzarajivatmi E. coli (EA 1257) concentrations of 0.1% on smooth surfaces and Staphylococcus aureus concentration of 0.05% in 1 hour from the calculation of 0.25-0.3 litres/m2. Disinfection of rough test surfaces against Escherichia coli and Staphylococcus aureus occurred after treatment with 0,3% solution of 3-hour exposure, at a rate of 0.5 l/m2. It was also found that 1.0% solution "Polied" fully obezzarazhivatel test the surface of mycobacteria (PCs-5) and at double the 0.6% concentration for 24 hours. Disinfection of rough test surfaces contaminated with spores of B. cereus (PCs 96) was achieved with a 4.0% solution at twice the irrigation rate of 0.5 l/m2 at an exposure of 24 hours. Toxicity solutions of the drug "Polied" refer to "moderate" threat (hazard class 3) and low-hazard substances (4 hazard class) when applied to the skin, mucous membranes of the eyes, and inhalation exposure on the respiratory system.


2018 ◽  
Vol 41 (4) ◽  
pp. 353-363
Author(s):  
Alberto J. Valencia-Botin ◽  
Melesio Gutiérrez-Lomelí ◽  
Juan A. Morales-Del-Río ◽  
Pedro J. Guerrero-Medina ◽  
Miguel A. Robles-García ◽  
...  

Actualmente existe la necesidad de hacer frente al problema de la resistencia a los antibióticos y al uso indiscriminado de fungicidas químicos en la agricultura. El objetivo de este trabajo fue evaluar el efecto inhibitorio de extractos acuosos, metanólicos, acetónicos y hexánicos de hoja y tallo de Vitex mollis Kunth (Lamiaceae) contra diferentes bacterias (Escherichia coli, Micrococcus luteus, Salmonella enterica y Staphylococcus aureus) y especies del hongo Fusarium (F. verticillioides, F. oxysporum, F. tapsinum y F. oxysporum f.sp. lycopersici) de importancia en la salud y en la agricultura, así como determinar su composición química general. Se determinaron las concentraciones inhibitorias mínimas (CIM) de todos los extractos por la técnica de microdilución, excepto del hexánico, que no presentó inhibición en las bacterias estudiadas. S. enterica fue la bacteria que mostró mayor sensibilidad al extracto metanólico de tallo (CIM = 28 μg mL-1), le siguieron M. luteus (CIM = 32 μg mL-1), S. aureus (CIM = 75 μg mL-1) y E. coli (CIM = 80 μg mL- 1). Los extractos metanólicos y acuosos de tallo presentaron mayor porcentaje de inhibición contra los diferentes tipos de Fusarium evaluados por el método de dilución en agar. Los extractos de V. mollis inhibieron a F. verticillioides entre 62 y 91 % con 120 μg mL-1 de extracto. El orden de las especies de hongos inhibidas por los extractos fue: F. verticillioides > F. oxysporum > F. tapsinum > F. oxysporum f.sp. lycopersici. La composición química de las especies se determinó mediante pruebas para fenoles, taninos, flavonoides, triterpenos, alcaloides, cumarinas y saponinas. Ninguno de los extractos presentó alcaloides y saponinas. Los fenoles (37.1 mg EAG/g muestra seca) y flavonoides (26.8 mg EQ/g muestra seca) fueron los compuestos mayoritarios en los extractos metanólicos y acuosos. En conclusión, se requieren cantidades muy pequeñas de extracto para la inhibición de bacterias y de Fusarium; por lo tanto, V. mollis puede ser considerada una fuente de metabolitos para este fin y en la agricultura como control alternativo dentro de un manejo integrado de enfermedades.


2020 ◽  
Vol 10 (3) ◽  
pp. 316-329
Author(s):  
Fateme Mirzajani ◽  
Amin Hamidi

Introduction: In this project, the growth and volatile metabolites profiles of Escherichia coli (E. coli ) and Staphylococcus aureus were monitored under the influence of silver base chemical, nanoparticle and ultra-highly diluted compounds. Materials & Methods: The treatments were done for 12000 life cycles using silver nanoparticles (AgNPs) as well as ultra-highly diluted Argentum nitricum (Arg-n). Volatile organic metabolites analysis was performed using gas chromatography mass spectrometry (GC-MS). The results indicated that AgNPs treatment made the bacteria resistant and adapted to growth in the nanoparticle condition. The use of ultra-highly diluted Arg-n initially increased growth but it decreased later. Also, with the continuous usage of these materials, no more bacterial growth was observed. Results: The most important compounds produced by E. coli are Acetophenone, Octyl acetate, Styrene, 1,8-cineole, 4-t-butyl-2-(1-methyl-2-nitroethyl)cyclohexane, hexadecane and 2-Undecanol. The main compounds derived from S. aureus are Acetophenone,1,8-cineole, Benzaldehyde, 2-Hexan-1-ol, Tridecanol, Dimethyl Octenal and tetradecane. Acetophenone and 1,8-cineole were common and produced by both organisms. Conclusion: Based on the origin of the produced volatiles, main volatiles percentage of untreated sample is hydrocarbon (>50%), while bacteria treatments convert the ratio in to aldehydes, ketones and alcohols in the case of AgNPs, (>80%) and aldehydes, ketones and terpenes in the case of Arg-n (>70%).


Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1786
Author(s):  
György Schneider ◽  
Bettina Schweitzer ◽  
Anita Steinbach ◽  
Botond Zsombor Pertics ◽  
Alysia Cox ◽  
...  

Contamination of meats and meat products with foodborne pathogenic bacteria raises serious safety issues in the food industry. The antibacterial activities of phosphorous-fluorine co-doped TiO2 nanoparticles (PF-TiO2) were investigated against seven foodborne pathogenic bacteria: Campylobacter jejuni, Salmonella Typhimurium, Enterohaemorrhagic E. coli, Yersinia enterocolitica, Shewanella putrefaciens, Listeria monocytogenes and Staphylococcus aureus. PF-TiO2 NPs were synthesized hydrothermally at 250 °C for 1, 3, 6 or 12 h, and then tested at three different concentrations (500 μg/mL, 100 μg/mL, 20 μg/mL) for the inactivation of foodborne bacteria under UVA irradiation, daylight exposure or dark conditions. The antibacterial efficacies were compared after 30 min of exposure to light. Distinct differences in the antibacterial activities of the PF-TiO2 NPs, and the susceptibilities of tested foodborne pathogenic bacterium species were found. PF-TiO2/3 h and PF-TiO2/6 h showed the highest antibacterial activity by decreasing the living bacterial cell number from ~106 by ~5 log (L. monocytogenes), ~4 log (EHEC), ~3 log (Y. enterolcolitca, S. putrefaciens) and ~2.5 log (S. aureus), along with complete eradication of C. jejuni and S. Typhimurium. Efficacy of PF-TiO2/1 h and PF-TiO2/12 h NPs was lower, typically causing a ~2–4 log decrease in colony forming units depending on the tested bacterium while the effect of PF-TiO2/0 h was comparable to P25 TiO2, a commercial TiO2 with high photocatalytic activity. Our results show that PF-co-doping of TiO2 NPs enhanced the antibacterial action against foodborne pathogenic bacteria and are potential candidates for use in the food industry as active surface components, potentially contributing to the production of meats that are safe for consumption.


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