Antibacterial Effects of Different Food-Related Phosphates Using Aeromonas hydrophila

2001 ◽  
Vol 64 (2) ◽  
pp. 195-200 ◽  
Author(s):  
LIDIA del C. VELÁZQUEZ ◽  
MARÍA E. ESCUDERO ◽  
ANA MARÍA S. de GUZMÁN

Aeromonas hydrophila is considered to be an emergent food-related bacterium. Phosphates are used as additives, mainly in meat products, to improve the quality of these foods. The antibacterial properties of phosphates are also well known. In this work, two A. hydrophila strains in early exponential phase were used: (A) A. hydrophila ATCC 7965 and (B) A. hydrophila derived from food, isolated in our laboratory. MIC and MBC studies were performed to assess the antibacterial effects of four phosphates assayed in brain heart infusion broth (BHI) and modified complete defined synthetic medium (mCDS) as compared to cooked ground meat medium (CM). The MBC values of the phosphates in CM were significantly higher than MIC values in BHI broth and mCDS medium (P < 0.05). In the two latter media, the growth of both A. hydrophila strains was totally inhibited by concentrations between 0.5 and 3.0%. Although all the assayed phosphates proved to have bactericidal effects on A. hydrophila, 0.5% sodium acid pyrophosphate (SAPP) exhibited greater effects in both strains and was selected for subsequent experiments. The bacteriolytic effect of SAPP was spectrophotometrically determined (260 nm of absorbance) by means of the leakage of intracellular nucleotides and microscopically confirmed by the presence of massive gelatinous aggregates. These were identified by enzymes (RNase, DNase, and proteinase) that hydrolyzed the nucleotides and proteins released during cellular lysis in the presence of SAPP. It was concluded that 0.5% SAPP can have bactericidal and bacteriolytic effects in early exponential phase A. hydrophila cells.

1994 ◽  
Vol 57 (4) ◽  
pp. 284-288 ◽  
Author(s):  
RUBY M. LEE ◽  
PAUL A. HARTMAN ◽  
DENNIS G. OLSON ◽  
FRED D. WILLIAMS

Previous studies showed that levels as low as 0.1% sodium ultraphosphate (UP), 0.1% sodium polyphosphate glassy (SPG) and 0.5% tetrasodium pyrophosphate (TSPP) were bactericidal and bacteriolytic to early-exponential phase cells of Staphylococcus aureus ISP40 8325. In the present study, Ca2+ (0.01 M) or Mg2+ (0.01 M) reversed the bacteriolytic effects of UP (0.1%) and SPG (0.1%) to S. aureus. In addition, Ca2+ (0.01 M) or Mg2+ (0.01 M), when added to the culture medium before inoculation, protected cells from growth inhibition by UP and SPG. Moreover, the bactericidal effects of UP or SPG were reversed by Ca2+ or Mg2+ in metal-rescue experiments in which the metals were added to polyphosphate-containing medium after 1 h of incubation. No additive effect existed between Mg2+ and Ca2+. Growth inhibition of TSPP was not reversed by Mg2+ or Ca2+, but it was reversed by Fe3+ when Fe3+ was added to protect cells 1 h before the addition of TSPP. These studies show that the antibacterial effects of phosphates can be altered substantially by the metal-ion content of the environment.


Author(s):  
Azadeh Foroughi ◽  
Pouya Pournaghi ◽  
Fariba Najafi ◽  
Akram Zangeneh ◽  
Mohammad Mahdi Zangeneh ◽  
...  

Medicinal plants are considered modern resources for producing agents that could act as alternatives to antibiotics in demeanor of antibiotic-resistant bacteria. The aim of the study was to evaluate the chemical composition and antibacterial activities of essential oil of Foeniculum vulgare (FV) against Pseudomonas aeruginosa and Bacillus subtilis. Gas chromatography mass spectrometry was done to specify chemical composion. As a screen test to detect antibacterial properties of the essential oil, agar disk and agar well diffusion methods were employed. Macrobroth tube test was performed to determinate MIC. The results indicated that the most substance found in FV essential oil was Trans-anethole (47.41 %), also the essential oil of FV with 0.007 g/ml concentration has prevented P. aeruginosa and with 0.002 g/ml concentration has prevented B. subtilis from the growth. Thus, the research represents the antibacterial effects of the medical herb on test P. aeruginosa and B. subtilis. We believe that the article provide support to the antibacterial properties of the essential oil. The results indicate the fact that the essential oil from the plant can be useful as medicinal or preservatives composition.


Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 845
Author(s):  
Candace Goodman ◽  
Katrina N. Lyon ◽  
Aitana Scotto ◽  
Cyra Smith ◽  
Thomas A. Sebrell ◽  
...  

Helicobacter pylori infection is commonly treated with a combination of antibiotics and proton pump inhibitors. However, since H. pylori is becoming increasingly resistant to standard antibiotic regimens, novel treatment strategies are needed. Previous studies have demonstrated that black and red berries may have antibacterial properties. Therefore, we analyzed the antibacterial effects of black and red raspberries and blackberries on H. pylori. Freeze-dried powders and organic extracts from black and red raspberries and blackberries were prepared, and high-performance liquid chromatography was used to measure the concentrations of anthocyanins, which are considered the major active ingredients. To monitor antibiotic effects of the berry preparations on H. pylori, a high-throughput metabolic growth assay based on the Biolog system was developed and validated with the antibiotic metronidazole. Biocompatibility was analyzed using human gastric organoids. All berry preparations tested had significant bactericidal effects in vitro, with MIC90 values ranging from 0.49 to 4.17%. Antimicrobial activity was higher for extracts than powders and appeared to be independent of the anthocyanin concentration. Importantly, human gastric epithelial cell viability was not negatively impacted by black raspberry extract applied at the concentration required for complete bacterial growth inhibition. Our data suggest that black and red raspberry and blackberry extracts may have potential applications in the treatment and prevention of H. pylori infection but differ widely in their MICs. Moreover, we demonstrate that the Biolog metabolic assay is suitable for high-throughput antimicrobial susceptibility screening of H. pylori.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1241
Author(s):  
Yuthana Phimolsiripol ◽  
Srirana Buadoktoom ◽  
Pimporn Leelapornpisid ◽  
Kittisak Jantanasakulwong ◽  
Phisit Seesuriyachan ◽  
...  

The effect of ultrasonication on the antioxidant and antibacterial properties of Ceylon spinach (Basella alba) extracts (CE) and the shelf life of chilled pork with CE were studied. The CE were ultrasonicated at different power levels (60–100%) for 10–40 min in an ultrasonic bath with the rise of antioxidant activities (p ≤ 0.05) proportional to the ultrasonication time. The additional investigation of antibacterial activities showed that the ultrasonicated extracts (100 mg/mL) could inhibit and inactivate Staphylococcus aureus and Escherichia coli with the optimal condition of 80% power for 40 min. For shelf-life testing, fresh pork treated with the ultrasonicated extracts at 100 and 120 mg/mL had lower values of thiobarbituric acid reactive substances (TBARS) than the control (without dipping). For food safety as measured by the total microbial count, the fresh pork dipped with 100–120 mg/mL CE extract could be kept at 0 °C for 7 days, 2 to 3 days longer than control meat at 0 and 4 °C, respectively. A sensory evaluation using a nine-point hedonic scale showed that fresh pork dipped with 100-mg/mL CE extracts was accepted by consumers. It is suggested that CE extracts can be applied in the food industry to enhance the quality and extend the shelf life of meat products.


2008 ◽  
Vol 75 (3) ◽  
pp. 875-877 ◽  
Author(s):  
Javier Calzada ◽  
Mar�a T. Zamarro ◽  
Almudena Alc�n ◽  
Victoria E. Santos ◽  
Eduardo D�az ◽  
...  

ABSTRACT Biodesulfurization was monitored in a recombinant Pseudomonas putida CECT5279 strain. DszB desulfinase activity reached a sharp maximum at the early exponential phase, but it rapidly decreased at later growth phases. A model two-step resting-cell process combining sequentially P. putida cells from the late and early exponential growth phases was designed to significantly increase biodesulfurization.


1981 ◽  
Vol 8 (1) ◽  
pp. 31-35 ◽  
Author(s):  
Esam M. Ahmed ◽  
Roger L. West

Abstract Beef chuck and plate cuts obtained from U.S.D.A. utility grade carcass were mixed and ground through a 0.318 cm plate. The ground meat was extended with extruded and non-extruded defatted peanut meal. Hydrated defatted peanut meal was added at the rate of 20 and 30 parts to 80 and 70 parts of the ground meat, respectively. All treatments were formulated to contain 20% fat in the final patty and loaf products. Extruded and non-extruded meat products were stored at −18 C for periods up to 6 weeks. All quality evaluations were conducted on cooked meat products. Ground meat patties and loaves extended with non-extruded peanut meal exhibited similar cooking losses to those either extended with extruded peanut meal or 100% beef products. Control meat products stored for 4 weeks or longer required larger forces to shear than the non-stored patties. Freezing storage of the extended meat products did not result in a change of shearing forces. These forces were similar to the shearing force exhibited by freshly prepared products. Trained sensory panelists indicated that extended meat patties were more tender and less cohesive than non-extended patties. However, sensory acceptability tests indicated similar acceptability ratings for the extended and non-extended meat patties and loaves.


1942 ◽  
Vol 75 (4) ◽  
pp. 383-394 ◽  
Author(s):  
W. Barry Wood ◽  
Robert Austrian

1. In cultures of Staphylococus aureus in a synthetic medium nicotinamide and cozymase were shown to block the bacteriostatic action of chemically unrelated sulfonamide drugs as well as the chemically related compound sulfapyridine. The antibacterial properties of organic dyes totally unrelated to the sulfonamide compounds (methylene blue and thionine) were also nullified by the addition of cozymase to the culture medium. 2. The antagonistic action of the pyridine-containing coenzyme, cozymase, was found, by quantitative study, to be no greater against sulfapyridine than against other structurally dissimilar sulfonamide compounds. 3. The antidrug effects of nicotinamide and cozymase in staphylococcus cultures were observed to be directly proportional to their ability to stimulate the growth of the organism in the synthetic medium. When tested in cultures of B. coli in which they failed to accelerate bacterial growth, these same substances failed to influence the bacteriostatic action of the sulfonamide drugs. 4. The in vitro action of the coenzyme, cocarboxylase, as measured in the Warburg respirometer, was shown to be unaffected by the chemically related drug, sulfathiazole, even when the latter was present in great excess. The above observations fail to support the theory that sulfapyridine, sulfathiazole, and sulfadiazine prevent bacterial growth by interfering with the functioning of the chemically related coenzymes, cozymase, and cocarboxylase. The mode of action of sulfanilamide and its more common derivatives is discussed in the light of these observations, and a tentative theory is offered to explain the differences in bacteriostatic potency exhibited by the various sulfonamide compounds.


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