Antibacterial Effects of Long-Chain Polyphosphates on Selected Spoilage and Pathogenic Bacteria

2008 ◽  
Vol 71 (7) ◽  
pp. 1401-1405 ◽  
Author(s):  
JEREMY A. OBRITSCH ◽  
DOJIN RYU ◽  
LUCINA E. LAMPILA ◽  
LLOYD B. BULLERMAN

The antimicrobial activities of four long-chain food-grade polyphosphates were studied at concentrations allowed in the food industry (<5,000 ppm) in defined basal media by determining the inhibition of growth of three gram-negative and four gram-positive spoilage and pathogenic bacteria. Both generation time and lag phase of Escherichia coli K-12, E. coli O157: H7, and Salmonella Typhimurium were increased with all of the polyphosphates tested. Bacillus subtilis and Staphylococcus aureus were more sensitive to polyphosphates, but not in all cases, with multiphased growth. The growth of Lactobacillus plantarum was inhibited by polyphosphates at concentrations above 750 ppm, but the lag time of Listeria monocytogenes was shortened by the presence of polyphosphates. No single polyphosphate was maximally inhibitory against all bacteria. Polyphosphates with chain lengths of 12 to 15 were significantly different from those with chain lengths of 18 to 21 depending on the organism and concentrations of polyphosphate used. Overall, higher polyphosphate concentrations resulted in greater inhibition of bacterial growth.

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.


2021 ◽  
Vol 14 (5) ◽  
pp. 414
Author(s):  
Neda Aničić ◽  
Uroš Gašić ◽  
Feng Lu ◽  
Ana Ćirić ◽  
Marija Ivanov ◽  
...  

Two Balkan Peninsula endemics, Nepeta rtanjensis and N. argolica subsp. argolica, both characterized by specialized metabolite profiles predominated by iridoids and phenolics, are differentiated according to the stereochemistry of major iridoid aglycone nepetalactone (NL). For the first time, the present study provides a comparative analysis of antimicrobial and immunomodulating activities of the two Nepeta species and their major iridoids isolated from natural sources—cis,trans-NL, trans,cis-NL, and 1,5,9-epideoxyloganic acid (1,5,9-eDLA), as well as of phenolic acid rosmarinic acid (RA). Methanol extracts and pure iridoids displayed excellent antimicrobial activity against eight strains of bacteria and seven strains of fungi. They were especially potent against food-borne pathogens such as L. monocytogenes, E. coli, S. aureus, Penicillium sp., and Aspergillus sp. Targeted iridoids were efficient agents in preventing biofilm formation of resistant P. aeruginosa strain, and they displayed additive antimicrobial interaction. Iridoids are, to a great extent, responsible for the prominent antimicrobial activities of the two Nepeta species, although are probably minor contributors to the moderate immunomodulatory effects. The analyzed iridoids and RA, individually or in mixtures, have the potential to be used in the pharmaceutical industry as potent antimicrobials, and in the food industry to increase the shelf life and safety of food products.


Microbiology ◽  
2009 ◽  
Vol 155 (11) ◽  
pp. 3589-3598 ◽  
Author(s):  
Gaylen A. Uhlich

Escherichia coli K-12 defends itself against peroxide-mediated oxidative damage using two catalases, KatG and KatE, and the peroxiredoxin, alkyl hydroperoxide reductase, encoded by ahpC. In E. coli O157 : H7 strain ATCC 43895 (EDL933), plasmid pO157 carries an additional catalase-peroxidase gene, katP. KatP has been shown to be a functional catalase-peroxidase. However, deletion of pO157 does not alter the peroxide resistance of strain EDL933, leaving the physiological role of katP unclear. To examine the individual roles of peroxide-resistance genes in E. coli O157 : H7, mutant strains of ATCC 43895 were constructed bearing individual deletions of katG, katE, katP and ahpC, as well as double, triple and quadruple deletions encompassing all possible gene combinations thereof. The wild-type and all 15 mutant strains were compared for differences in aerobic growth, ability to scavenge exogenous H2O2 and resistance to exogenous peroxides. Although KatG scavenged the most exogenous H2O2, KatP scavenged statistically greater amounts than either KatE or AhpC during exponential growth. However, katG and ahpC together were sufficient for full peroxide resistance in disc diffusion assays. Strains with only katG or ahpC were the only triple deletion strains with significantly shorter generation times than the quadruple deletion strain. ahpC was the only gene that could allow rapid transition from lag phase to exponential phase in a triple deletion strain. Gene expression studies revealed that katP is an OxyR-regulated gene, but its expression is suppressed in stationary phase by RpoS. These studies indicate that pO157-borne katP contributes to the complex gene network protecting strain 43895 from peroxide-mediated oxidative damage in an OxyR-dependent manner.


2013 ◽  
Vol 76 (9) ◽  
pp. 1539-1548 ◽  
Author(s):  
SARISA SURIYARAK ◽  
CHRISTELLE BAYRASY ◽  
HERBERT SCHMIDT ◽  
PIERRE VILLENEUVE ◽  
JOCHEN WEISS

The effect of the addition of a newly synthesized series of rosmarinic acid (RA) esters (REs) and alcohols with chain lengths of 1,4, 8, 10, 12,16, and 18 carbons (REI to 18) on the growth behavior of Staphylococcus carnosus LTH1502 and Esclierichia coli K-12 LTH4263 was investigated. An initial microtiter dilution assay indicated activity of compounds against S. carnosus LTH1502 only, but not E. coli K-12 LTH4263, and a strong dependence of growth inhibition of S. carnosus LTH1502 on the esters' alkyl acid chain lengths. Esters with chains shorter than 8 and longer than 12 had little effect against S. carnosus LTH1502, whereas esters with chain lengths between 8 and 12 inhibited growth. To better understand the dependence of the antimicrobial activity of the REs on alkyl chain lengths, RA, n-methyl rosmarinate (RE1), n-dodecyl rosmarinate (RE12), and n- octadecyl rosmarinate (RE18) were used in a time-kill assay against S. carnosus LTH1502. Compounds were added at 0.75 mM in the lag phase, 5 mM in the exponential phase, and 10 mM in the stationary phase. RA had no effect in the lag and exponential phases but decreased cell counts during the stationary phase. In contrast, RE1 and RE12 decreased cell numbers in all three phases, with RE12 reducing counts most rapidly. Addition of RE18 did not affect growth regardless of the growth phase. Appearance and physiological State of S. carnosus LTH1502 cells treated with 200 mM RA after 48 h and with 10 mM RE12 after4 h were observed by fluorescence microscopy. Images indicated differenees in the way the compounds interacted with and damaged cells. Results were attributed to the different physicochemical properties of RA and its esters.


2020 ◽  
Vol 10 (4) ◽  
pp. 5918-5922 ◽  

A double green approach to the synthesis of silver nanoparticles using chitosan as a reducing agent and microwave radiation has been carried out in this study. Chitosan was extracted from marine crab carapace and the morphology of the produced chitosan was characterized using Scanning Electron Microscope (SEM). The production of silver nanoparticles (AgNPs) was monitored by the formation of surface plasmon resonance (SPR) at the λmax= 420 nm, indicates the reduction of the oxidation state of Ag+ to Ag0. The XRD data confirms the crystallinity nature of obtained AgNps, while the SEM and TEM revealed the formation of near-spherical shapes, polydisperse, heterogeneous distribution of AgNps with the size range between 7 to 25 nm. The antimicrobial activities of the AgNPs were investigated using The prepared AgNPs demonstrated dual mechanism action with chitosan, which acted as a stabilizer on the surface of AgNPs, and enhance the inhibition zone against E. tarda and E. coli. Therefore, the synthesized AgNPs in this study may have excellent potential for clinical application as it is green, low-cost and eco-friendly.


2020 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Alce Magani ◽  
Trina Tallei ◽  
Beivy Kolondam

Uji Antibakteri Nanopartikel Kitosan terhadap Pertumbuhan Bakteri Staphylococcus aureus dan Escherichia coli.(Antibacterial Test of Chitosan Nanoparticles against Staphylococcus Aureus and Escherichia coli) Alce K. Magani*, Trina E. Tallei, Beivy J. KolondamProgram Studi Biologi, FMIPA Universitas Sam Ratulangi, Manado 95115*Email korespondensi: [email protected] (Article History: Received 30-12-2019; Revised 15-01-2020; Accepted 23-01-2020) Abstrak Antibakteri merupakan zat yang dapat menghambat pertumbuhan bakteri dan dapat membunuh bakteri penyebab infeksi. Staphylococcus aureus dan Escherichia coli merupakan bakteri Gram positif dan Gram negatif yang dapat menimbulkan infeksi atau penyakit dalam tubuh. Penelitian ini bertujuan untuk menguji aktivitas bakteri patogen dengan memakai nanopartikel kitosan sebagai antibakteri yang dibuat dalam empat konsentrasi (0,5%, 1%, 1,5% dan 2%) serta penggunaan kontrol asam asetat 1%, ciprofloxacin dan air steril sebagai pembanding. Metode penelitian yang digunakan yaitu metode gelasi ionik untuk pembuatan nanopartikel kitosan dan difusi agar untuk pengujian antibakteri. Data dianalisis dengan One Way Anova yang dilanjutkan dengan metode BNT (Beda Nyata Terkecil). Hasil penelitian diperoleh penghambatan pertumbuhan bakteri S. aureus dan E. coli tertinggi pada konsentrasi 0,5%, dengan diameter zona hambat hari pertama sampai hari ketiga 12,31 mm, 9,98 mm, dan 20,46 mm pada S. aureus dan 15,88 mm, 18,71 mm, dan 20,43 mm pada E. coli, kategori kuat, dan bersifat bakteriostatik dan penghambatan terendah pada konsentrasi 2% dengan diameter zona hambat pada S. aureus yaitu 5,56 mm, 5,50 mm, dan 5,40 mm, dan pada E. coli yaitu 5,93 mm, 9,64 mm, dan 12,58 mm, kategori sedang, dan bersifat bakteriostatik. Kata kunci: Kitosan, nanopartikel kitosan, aktivitas antibakteri.  Abstract Antibacteria is a substance that can inhibit the growth of bacteria and able to kill bacteria that cause infections. Staphylococcus aureus and Escherichia coli are Gram positive and Gram negative bacteria that able to cause infections or diseases. This study aimed to examine the activity of pathogenic bacteria by using chitosan nanoparticles as antibacterial. The treatments were made in four concentrations (0.5%, 1%, 1.5% and 2%) and, for comparison, there were also acetic acid control, ciprofloxacin and sterile water. The research method used is the ionic gelation method for the manufacture of chitosan nanoparticles and agar diffusion for antibacterial testing. Data were analyzed with One Way Anova followed by LSD (Least Significant Difference) method. The results showed the highest inhibition of growth of S. aureus and E. coli bacteria at a concentration of 0.5%, with a diameter of inhibition zones of the first day to the third day of 12.31 mm, 9.98 mm, and 20.46 mm in S. aureus and 15,88 mm, 18,71 mm, and 20,43 mm in E. coli, the strong category, and are bacteriostatic and the lowest inhibition was at 2% concentration with inhibition zone diameters in S. aureus namely 5.568 mm, 5.50 mm, and 5, 40 mm, and in E. coli, 5.93 mm, 9.63 mm and 12.58 mm, the medium category and bacteriostatic.Key words: Chitosan, nanoparticles chitosan, antibacterial activity.


2020 ◽  
Vol 10 (1) ◽  
pp. 7
Author(s):  
Alce K Magani ◽  
Trina E Tallei ◽  
Beivy J Kolondam

Uji Antibakteri Nanopartikel Kitosan terhadap Pertumbuhan Bakteri Staphylococcus aureus dan Escherichia coli.(Antibacterial Test of Chitosan Nanoparticles against Staphylococcus aureus and Escherichia coli) Alce K. Magani*, Trina E. Tallei, Beivy J. KolondamProgram Studi Biologi, FMIPA Universitas Sam Ratulangi, Manado 95115*Email korespondensi: [email protected] (Article History: Received 30-12-2019; Revised 15-01-2020; Accepted 23-01-2020) Abstrak Antibakteri merupakan zat yang dapat menghambat pertumbuhan bakteri dan dapat membunuh bakteri penyebab infeksi. Staphylococcus aureus dan Escherichia coli merupakan bakteri Gram positif dan Gram negatif yang dapat menimbulkan infeksi atau penyakit dalam tubuh. Penelitian ini bertujuan untuk menguji aktivitas bakteri patogen dengan memakai nanopartikel kitosan sebagai antibakteri yang dibuat dalam empat konsentrasi (0,5%, 1%, 1,5% dan 2%) serta penggunaan kontrol asam asetat 1%, ciprofloxacin dan air steril sebagai pembanding. Metode penelitian yang digunakan yaitu metode gelasi ionik untuk pembuatan nanopartikel kitosan dan difusi agar untuk pengujian antibakteri. Data dianalisis dengan One Way Anova yang dilanjutkan dengan metode BNT (Beda Nyata Terkecil). Hasil penelitian diperoleh penghambatan pertumbuhan bakteri S. aureus dan E. coli tertinggi pada konsentrasi 0,5%, dengan diameter zona hambat hari pertama sampai hari ketiga 12,31 mm, 9,98 mm, dan 20,46 mm pada S. aureus dan 15,88 mm, 18,71 mm, dan 20,43 mm pada E. coli, kategori kuat, dan bersifat bakteriostatik dan penghambatan terendah pada konsentrasi 2% dengan diameter zona hambat pada S. aureus yaitu 5,56 mm, 5,50 mm, dan 5,40 mm, dan pada E. coli yaitu 5,93 mm, 9,64 mm, dan 12,58 mm, kategori sedang, dan bersifat bakteriostatik. Kata kunci: Kitosan, nanopartikel kitosan, aktivitas antibakteri.  Abstract Antibacteria is a substance that can inhibit the growth of bacteria and able to kill bacteria that cause infections. Staphylococcus aureus and Escherichia coli are Gram positive and Gram negative bacteria that able to cause infections or diseases. This study aimed to examine the activity of pathogenic bacteria by using chitosan nanoparticles as antibacterial. The treatments were made in four concentrations (0.5%, 1%, 1.5% and 2%) and, for comparison, there were also acetic acid control, ciprofloxacin and sterile water. The research method used is the ionic gelation method for the manufacture of chitosan nanoparticles and agar diffusion for antibacterial testing. Data were analyzed with One Way Anova followed by LSD (Least Significant Difference) method. The results showed the highest inhibition of growth of S. aureus and E. coli bacteria at a concentration of 0.5%, with a diameter of inhibition zones of the first day to the third day of 12.31 mm, 9.98 mm, and 20.46 mm in S. aureus and 15,88 mm, 18,71 mm, and 20,43 mm in E. coli, the strong category, and are bacteriostatic and the lowest inhibition was at 2% concentration with inhibition zone diameters in S. aureus namely 5.568 mm, 5.50 mm, and 5, 40 mm, and in E. coli, 5.93 mm, 9.63 mm and 12.58 mm, the medium category and bacteriostatic.Key words: Chitosan, nanoparticles chitosan, antibacterial activity.


2019 ◽  
Vol 4 (1) ◽  
pp. 26-30 ◽  
Author(s):  
Hassan Mohammad Tawfeeq ◽  
Mohammed Hassan Fatah ◽  
Ahmed Mohammed Tofiq

Every day new sources of microbial and especially bacterial infections are reported, which are not taken into account, the fact that these sources have been implicated in the outbreaks of these infections. The goals of the current research focused on the exploration of the scope of microbial pollution of the widely traded paper currency notes of the Iraqi currencies (250, 1000 and 5000 Iraqi Dinars) in Kalar city. 300 banknotes (100 samples for each of the denominations under investigation) in circulation were gathered from different categories of Kalar population and one fresh sample for each of the three currencies (control negative). Each bill was rinsed in 5 ml D.W then cultured on Nutrient agar, Mannitol Salt agar and MacConkey agar, respectively, then incubated at 37 ºC for up to 48 hours. Results revealed the rate of microbial contamination, specifically bacterial ones as 94%, 68%, and 60%, respectively on the denominations of 250, 1000, and 5000 of Iraqi Dinars. In a descending order, and with regard to the prevalence rate, bacterial species contaminated 250, 1000 and 5000 Iraqi denominations respectively were as follows: 55.31%, 32.35% and 36.66% for Bacillus sp.; 14.89%, 38.23% and 20% for coagulase-negative Staphylococcus; 8.51%, 8.82% and 20% for E. coli; 2.12%, 11.76 and 20% for Pseudomonas sp.; 2.12% for each of Klebsiella sp., and Salmonella sp.; 10.63% and 4.25% for Enterobacter sp. and Staphylococcus aureus, respectively, and only on 250 denomination;  2.94% and 5.88% for each of Corynebacterium sp. and Serratia sp. only on 1000 currency note; lastly, 3.33% for Proteus sp. on 5000 IQD only. These outcomes suggest that bacterial contamination of Iraqi Dinars, specifically the 250 denomination is risky and could be regarded as the real source of infectious diseases with the most dangerous pathogenic bacteria.  


2020 ◽  
Vol 12 (5) ◽  
pp. 695-701
Author(s):  
Sonika Sharma ◽  
Neeraj Sharma

The tris(nicotinohydroxamato) vanadium(III) complex of composition [V(C5H4NCONHO)3] have been synthesized by the reaction of VCl3 with three equivalents of potassium salts of nicotinohydroxamate in methanol medium under nitrogen atmosphere. The characterization of complex has been accomplished by elemental analyses, molar conductivity, magnetic moment measurements, IR, electronic and mass spectral studies. An octahedral geometry around vanadium, inferred from physicochemical and spectral studies has been proposed for complex. The antimicrobial activities of the newly synthesized complex, ligand and precursor VCl3 have been evaluated against some pathogenic bacteria as E. coli, S. aureus, S. typhi, S. paratyphi, S. epidermidis and K. pneumoniae and fungi such as A. niger, B. fulva and M. circinelloid by minimum inhibitory concentration method. The complex exhibited promising antimicrobial activity relative to free ligand and metal precursor.


1998 ◽  
Vol 61 (8) ◽  
pp. 1052-1056 ◽  
Author(s):  
MAIJA HATAKKA

The microbiological quality of 1,012 hot meals served on aircraft was studied in 1991 to 1994. The material included dishes prepared in 33 countries all over the world. The geometric means of aerobic colony counts and Escherichia coli were significantly lower in breakfasts (P < 0.05) than in main dishes. Pathogenic bacteria were found in 30 samples (3.0%), Bacillus cereus being the most common pathogen. The frequencies of B. cereus and Staphylococcus aureus did not differ between breakfasts and main dishes. Many of the samples exceeded the minimum acceptable microbiological standards recommended by the Association of European Airlines (AEA) for E. coli, S. aureus, B. cereus, Clostridium perfringens, and Salmonella; i.e., 8.2%, 0.6%, 0.7%, 0.7% and 0.3%, respectively. There were considerable differences in aerobic colony counts and E. coli counts between countries where the food was prepared.


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