scholarly journals Evaluation of the Effect of Radiofrequency Radiation Emitted From Wi-Fi Router and Mobile Phone Simulator on the Antibacterial Susceptibility of Pathogenic Bacteria Listeria monocytogenes and Escherichia coli

Dose-Response ◽  
2017 ◽  
Vol 15 (1) ◽  
pp. 155932581668852 ◽  
Author(s):  
M. Taheri ◽  
S. M. J. Mortazavi ◽  
M. Moradi ◽  
S. Mansouri ◽  
G. R. Hatam ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Mobile Phone ◽  
Electromagnetic Fields ◽  
Pathogenic Bacteria ◽  
Wide Spectrum ◽  
Inhibition Zone ◽  
Base Stations ◽  
Radiofrequency Radiation ◽  
Pure Cultures

Mobile phones and Wi-Fi radiofrequency radiation are among the main sources of the exposure of the general population to radiofrequency electromagnetic fields (RF-EMF). Previous studies have shown that exposure of microorganisms to RF-EMFs can be associated with a wide spectrum of changes ranged from the modified bacterial growth to the alterations of the pattern of antibiotic resistance. Our laboratory at the nonionizing department of the Ionizing and Non-ionizing Radiation Protection Research Center has performed experiments on the health effects of exposure to animal models and humans to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile phone jammers, laptop computers, radars, dentistry cavitrons, magnetic resonance imaging, and Helmholtz coils. On the other hand, we have previously studied different aspects of the challenging issue of the ionizing or nonionizing radiation-induced alterations in the susceptibility of microorganisms to antibiotics. In this study, we assessed if the exposure to 900 MHz GSM mobile phone radiation and 2.4 GHz radiofrequency radiation emitted from common Wi-Fi routers alters the susceptibility of microorganisms to different antibiotics. The pure cultures of Listeria monocytogenes and Escherichia coli were exposed to RF-EMFs generated either by a GSM 900 MHz mobile phone simulator and a common 2.4 GHz Wi-Fi router. It is also shown that exposure to RF-EMFs within a narrow level of irradiation (an exposure window) makes microorganisms resistant to antibiotics. This adaptive phenomenon and its potential threats to human health should be further investigated in future experiments. Altogether, the findings of this study showed that exposure to Wi-Fi and RF simulator radiation can significantly alter the inhibition zone diameters and growth rate for L monocytogenes and E coli. These findings may have implications for the management of serious infectious diseases.

scholarly journals Evaluation of sanitary quality of goat milk in dairy industries from the Cariri region, state of Paraíba

2021 ◽  
Vol 10 (12) ◽  
pp. e596101220735
Author(s):  
Iara Nunes de Siqueira ◽  
Aline Antas Cordeiro Cavalcanti ◽  
Joyce Galvão de Souza ◽  
Filipe Jordão Pereira de Medeiros ◽  
João Carlos Taveira ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Pathogenic Bacteria ◽  
Goat Milk ◽  
Salmonella Spp ◽  
Pasteurized Milk ◽  
Enterococcus Spp ◽  
Bacillus Spp ◽  
Thermotolerant Coliforms ◽  
Staphylococcus Spp

The sanitary evaluation of equipment and hands is fundamental to investigate the presence of pathogens in the dairy industry. Then, this study aims to evaluate the sanitization of equipment, workers’ hands, raw and pasteurized milk in goat milk dairies in the Cariri region, state of Paraíba.  Collected 32 samples of four dairies represented by letters A, B, C, and D. The followings contents were analyzed: mesophiles, total and thermotolerant coliforms, Escherichia coli, Staphylococcus aureus, Samonella spp. and Listeria monocytogenes in the reception tank, pasteurization tank, packing machine, package, wall, workers’ hand, and each dairy’s raw and pasteurized milk. After isolation, 84 colonies were confirmed by MALDI TOF. The indicator microorganisms presented variations for the workers’ hands, while A and B stayed within the patterns. For the equipment, only dairy B was within limits. They were out of the standard for mesophiles, total coliforms, and thermotolerant regarding raw and pasteurized milk. The microorganisms, the Enterobacteriaceae family presented a higher frequency, with 77.38%, and within this family, Escherichia coli, Klebsiella spp., and Enterobacter spp. were the most prevalent. Gram-positive corresponded to 22.62%, Bacillus spp., Staphylococcus spp., Enterococcus spp., and Macrococcus caseolyticus. Listeria monocytogenes and Salmonella spp. were not isolated. These demonstrate failures in goat milk processing with pathogenic bacteria in several dairy plants, indicating the need to adjust the product’s quality control.

Inactivation of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella in Cranberry, Lemon, and Lime Juice Concentrates

2003 ◽  
Vol 66 (9) ◽  
pp. 1637-1641 ◽  
Author(s):  
MARA C. L. NOGUEIRA ◽  
OMAR A. OYARZÁBAL ◽  
DAVID E. GOMBAS
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Pathogenic Bacteria ◽  
Antimicrobial Properties ◽  
Escherichia Coli O157 ◽  
Bacterial Inactivation ◽  
Lime Juice ◽  
E Coli ◽  
Log Reduction ◽  
C 32

The production of thermally concentrated fruit juices uses temperatures high enough to achieve at least a 5-log reduction of pathogenic bacteria that can occur in raw juice. However, the transportation and storage of concentrates at low temperatures prior to final packaging is a common practice in the juice industry and introduces a potential risk for postconcentration contamination with pathogenic bacteria. The present study was undertaken to evaluate the likelihood of Escherichia coli O157: H7, Listeria monocytogenes and Salmonella surviving in cranberry, lemon, and lime juice concentrates at or above temperatures commonly used for transportation or storage of these concentrates. This study demonstrates that cranberry, lemon, and lime juice concentrates possess intrinsic antimicrobial properties that will eliminate these bacterial pathogens in the event of postconcentration recontamination. Bacterial inactivation was demonstrated under all conditions; at least 5-log Salmonella inactivation was consistently demonstrated at −23°C (−10°F), at least 5-log E. coli O157:H7 inactivation was consistently demonstrated at −11°C (12°F), and at least 5-log L. monocytogenes inactivation was consistently demonstrated at 0°C (32°F).

Inactivation of Pathogenic Bacteria by Cucumber Volatiles (E,Z)-2,6-Nonadienal and (E)-2-Nonenal†

2004 ◽  
Vol 67 (5) ◽  
pp. 1014-1016 ◽  
Author(s):  
M. J. CHO ◽  
R. W. BUESCHER ◽  
M. JOHNSON ◽  
M. JANES
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Bactericidal Activity ◽  
Pathogenic Bacteria ◽  
Brain Heart Infusion ◽  
Escherichia Coli O157 ◽  
Infusion Solution ◽  
E Coli ◽  
Log Reduction

The effects of (E,Z)-2,6-nonadienal (NDE) and (E)-2-nonenal (NE) on Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium were investigated. A suspension of each organism of 6 to 9 log CFU/ml was incubated for 1 h at 37° C in brain heart infusion solution that contained 0 to 500 or 1,000 ppm of NDE or NE. Depending on concentration, exposure to either NDE or NE caused a reduction in CFU of each organism. Treatment with 250 and 500 ppm NDE completely eliminated viable B. cereus and Salmonella Typhimurium cells, respectively. L. monocytogenes was the most resistant to NDE, showing only about a 2-log reduction from exposure to 500 ppm for 1 h. Conversely, this concentration of NDE caused a 5.8-log reduction in E. coli O157:H7 cells. NE was also effective in inactivating organisms listed above. A higher concentration of NE, 1,000 ppm, was required to kill E. coli O157:H7, L. monocytogenes, or Salmonella Typhimurium compared with NDE. In conclusion, both NDE and NE demonstrated an apparent bactericidal activity against these pathogens.

scholarly journals Uji Efek Antibakteri Jamur Endofit Akar Bakau Rhizophora stylosa Terhadap Bakteri Staphylococcus aureus dan Escherichia coli

2014 ◽  
Vol 2 (1) ◽  
Author(s):  
Michele Sumampouw
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Endophytic Fungi ◽  
Pathogenic Bacteria ◽  
Antibacterial Effect ◽  
Inhibition Zone ◽  
Potato Dextrose Agar ◽  
Rhizophora Stylosa ◽  
E Coli

Abstract: The aim of this study is to investigate the antibacterial effect of endophytic fungi originated from the root of mangrove Rhizophora stylosa growing on Mangrove Plantation Area around DAS Simpang 5 Jl. Piere Tendean Manado. The method of this research was using combination of PDA and NA media. Two species of endophytic fungi were extracted from the root of R. stylosa, black mycelium fungi as isolate A and brown mycelium fungi as isolate B. The activities of both isolates were tested against pathogenic bacteria Staphylococcus aureus and Escherichia coli. The result showed the same inhibition zone of isolate A and B to S. aureus, while, isolate A showed bigger the inhibition zone in comparison to isolate B against E. coli. As a conclusion, the endophytic fungi taken from the root of R. stylosa have antibacterial activity toward S. aureus and E. coli. Keywords: endophytic fungi, Rhizophora stylosa, antibacterial, Staphylococcus aureus, Escherichia coli.   Abstrak: Penelitian ini bertujuan untuk melihat adanya efek antibakteri dari jamur endofit yang diambil dari akar bakau Rhizophora stylosa yang ditanam di sekitar Perairan Daerah Aliran Sungai Simpang Lima Jl. Piere Tendean Manado. Metode penelitian dilakukan dengan menggunakan kombinasi media Potato Dextrose Agar (PDA) dan Nutrient Agar (NA). Dari akar bakau R. stylosa diperoleh dua  jenis jamur endofit yaitu isolat A dengan karateristik miselium jamur berwarna hitam dan isolat B yang dengan karakteristik miselium berwarna coklat. Kedua isolat ini selanjutnya diujikan aktivitasnya terhadap bakteri Staphylococcus aureus dan Escherichia coli. Hasil penelitian menunjukkan isolat A dan B memberikan  zona hambat yang sama terhadap bakteri Staphylococcus aureus dan pada bakteri Escherichia coli isolat A menunjukkan diameter zona hambat yang lebih besar dibandingkan isolat B. Kesimpulan, Jamur endofit yang diisolasi dari akar bakau R. Stylosa memiliki efek antibakteri terhadap pertumbuhan bakteri S. aureus dan E. coli. Kata kunci: jamur endofit, Rhizophopra stylosa, antibakteri, Staphylococcus aureus, Escherichia coli.

scholarly journals UJI AKTIVITAS ANTIBAKTERI EKSTRAK DAN FRAKSI SPONS Leucetta chagosensis DARI PERAIRAN PULAU MANTEHAGE SULAWESI UTARA TERHADAP PERTUMBUHAN BAKTERI Staphylococcus aureus DAN Escherichia coli

PHARMACON ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 834
Author(s):  
Eunike Pelealu ◽  
Defny S. Wewengkang ◽  
Surya Sumantri Abdullah
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacterial Growth ◽  
Pathogenic Bacteria ◽  
Inhibition Zone ◽  
Disk Diffusion ◽  
E Coli ◽  
Activity Test ◽  
Escherichia Coli Bacteria ◽  
Metabolite Content

ABSTRACTSponges are one of the biota components that make up coral reefs which are quite widely distributed. The metabolite content in the sponge can ward off and inhibit the pathogenic bacteria that interfere with it. This study aims to determine the activity of inhibiting bacterial growth from the extract and fraction of Leucetta chagosensis sponge against the growth of Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria. The samples were extracted using the maceration method with 95% ethanol solvent and then fractionated using 3 solvents with different polarity levels, namely methanol, n-hexane and chloroform. Activity test using the disk diffusion agar method of Kirby and Bauer. Only the MeOH fraction was able to inhibit the growth of E. coli bacteria with an average inhibition zone of 6.88 mm. Whereas for S.aureus bacteria extracts and all fractions showed activity to inhibit bacterial growth with an average inhibition zone of EtOH (6.61 mm), CHCI3 (6.68 mm), n-hexane (7.83 mm) and MeOH (8.00 mm), respectively. All activities that are shown are categorized as weak (weak).Keywords: Antibacterial, Leucetta chagosensis, Staphylococcus aureus, Escherichia coli ABSTRAKSpons merupakan salah satu komponen biota penyusun terumbu karang yang penyebarannya cukup luas. Kandungan metabolit yang ada di dalam spons dapat menangkal dan menghambat bakteri patogen pengganggunya.  Penelitian ini bertujuan untuk melihat aktivitas menghambat pertumbuhan bakteri dari ekstrak dan fraksi spons Leucetta chagosensis. terhadap pertumbuhan bakteri Gram positif Staphylococcus aureus dan Gram negatif Escherichia coli. Sampel di ekstraksi menggunakan metode maserasi dengan pelarut etanol 95% lalu di fraksinasi dengan menggunakan 3 pelarut dengan tingkat kepolaran yang berbeda yaitu metanol, n-heksan dan kloroform. Uji aktivitas menggunakan metode disk diffusion agar Kirby dan Bauer.  Hanya fraksi MeOH yang mampu menghambat pertumbuhan bakteri E.coli dengan zona hambat rata-rata 6,88 mm. Sedangkan terhadap bakteri S.aureus ekstrak dan semua fraksi menunjukan aktifitas menghambat pertumbuhan bakteri dengan rata-rata zona hambat masing-masing EtOH (6,61 mm), CHCl3 (6,68 mm), n-Heksan (7,83 mm), dan MeOH (8,00 mm). Semua aktivitas yang ditunjukan dikategorikan lemah (weak).Kata kunci : Antibakteri, Leucetta chagosensis, Staphylococcus aureus,  Escherichia coli

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