Fabrication and Characterization of PANI/Ag Nanocomposites Voltammetric Sensor for Foodborne Bacteria

2020 ◽  
Vol 10 (1) ◽  
pp. 51-56
Author(s):  
V. Chaitra ◽  
V. Uma ◽  
S. Raja

Introduction: Foodborne diseases are caused by consuming contaminated foods and/or beverages. Methods: Traditional detection methods for foodborne bacteria are sluggish and laborious. In this study, room temperature voltammetric sensors with low cost, specific, rapid and easy detection were fabricated using Polyaniline (PANI) and silver (Ag) nanoparticles. PANI films were coated on to the Indium Tin Oxide (ITO) glass substrate using electrochemical deposition technique. PANI surface was modified using Ag nanoparticles prepared by reduction method as Ag is one of the most powerful disinfectants against microbes. Both surface electron microscopy (SEM), X-ray diffraction (XRD) technique revealed the presence of Ag nanoparticles in the composites. The peaks observed in Fourier Transform Infrared Spectroscopy (FTIR) and optical absorption spectra are characteristics to PANI/Ag nanocomposites. Results: The antibacterial activities of the PANI/Ag nanocomposites were evaluated against Escherichia coli (E. Coli) (NCIM 2065), Staphylococcus aureus (S. aureus) (NCIM 2079) and Bacillus cereus (B. cereus) (NCIM 2106) using disk diffusion method. The composites showed better antibacterial activity due to the presence of Ag in comparison to pure PANI films. Conclusion: The sensor current for composites was found to increase with the presence of all the microbes. The sensitivity of the sensor was higher for E. coli bacteria among the other bacterial strains.

2017 ◽  
Vol 751 ◽  
pp. 270-276 ◽  
Author(s):  
Warot Prasanseang ◽  
Chaval Sriwong ◽  
Kittisak Choojun

Ag-natural rubber (Ag-NR) hybrid sheets were successfully prepared with a very simple and low cost method. In this method, silver nanoparticles (AgNPs) were firstly synthesized by a rapid and green microwave-assisted using polyvinylpyrroridone (PVP) media. The effect of PVP weight ratios towards the size of AgNPs was also investigated. Then, Ag-NR hybrid sheet samples were prepared by latex mixing-casting method using concentrated natural rubber (NR) latex with the synthesized AgNPs colloids. The characteristic absorption, particles sizes and shapes of the obtained AgNPs were examined through UV-vis, TEM and SAED. Also, the prepared Ag-NR sheet samples were characterized using XRD, FT-IR, SEM and EDS techniques. It was found that the particles sizes of all the synthesized AgNPs had spherical-like shape, and the mean sizes were increased from 29.7 to 90.4 nm upon increasing PVP contents. EDS results showed the AgNPs were well-dispersed and impregnated into the rubber matrix. Moreover, the antibacterial properties of the prepared Ag-NR sheets were tested by agar disk-diffusion method with Gram-positive and Gram-negative bacteria as Staphylococcus aureus(S. aureus) and Escherichia coli(E. coli), respectively. The results showed that the hybrid sheets exhibited excellent antibacterial properties against these bacteria, in which the zones of inhibition were also dependent on the synthesized AgNPs by utilizing the different amounts of PVP.


Author(s):  
SHIBU GEORGE ◽  
MEVLIN JOY

Objective: The objective of this study was to evaluate the antimicrobial activity of methanolic extract of Ludwigia parviflora L. using standard bacterial strains and compare its activity with that of standard antibiotics. Methods: The antibacterial activity and antibiotic susceptibility tests were done by disk diffusion method using MTCC bacterial strains. Results: The study revealed that the methanolic extract of the whole plant of L. parviflora L. was effective to inhibit the growth of Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli. Among the tested strains, S. aureus, P. aeruginosa, K. pneumoniae, and E. coli were more susceptible to the methanolic extract of L. parviflora than the commonly using antibiotic tetracycline 30 mcg. The activity of methanolic extract was also higher than the activity of gentamicin 10 mcg against the P. aeruginosa. Conclusion: The study concluded that the crude methanolic extract of the whole plant of L. parviflora L. is a good source for antibacterial agent against S. aureus, P. aeruginosa, K. pneumoniae, and E. coli. Hence, this plant can be used as a natural alternative to the common antibiotics such as gentamicin and tetracycline against common bacterial infections after validating its pharmacological and toxicological activities.


2020 ◽  
Author(s):  
Rene DEMBELE ◽  
Ali Konaté ◽  
Issiaka Soulama ◽  
Wendpoulomdé A. D. Kaboré ◽  
Assèta Kagambèga ◽  
...  

Abstract Background In recent years, Carbapenemase-producing Enterobacteriaceae (CPE) resistance to antibiotics has dramatically increased leading to limitations of their treatment options. In the present study, we investigated the occurrence of carbapenemase-producing Escherichia coli and Salmonella in rural Burkina Faso, using bacterial strains obtained from previous studies. Results Diarrheagenic Escherichia coli (DEC) strains was identified using 16-plex Polymerase Chain Reaction (PCR), whereas antibiotic susceptibility was realized using the disk diffusion method. Furthermore, multiplex PCR assays were used to characterize bla KPC, bla VIM and bla IMP genes in carbapenemase-producing E . coli and Salmonella . The study highlighted high resistance rates of the identified bacteria to common antibiotics. Likewise, two strains of E . coli were imipenem resistant with Carbapenemase-encoding genes. The genes detected were Klebsiella pneumoniae carbapenemase (KPC), Verona integrin-encoded metallo-β-lactamase (VIM) and Imipenemase (IMP-2) reaching a rate of 40% each. However, no Carbapenemase-encoding genes were detected in Salmonella isolates. Conclusions This study showed that for a real-time infection control and prompt application of antimicrobial chemotherapy, characterization of carbapenemase-producing Enterobacteriaceae in patients is crucial.


INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (07) ◽  
pp. 5-9
Author(s):  
R. G Ingle ◽  
◽  
S. J. Wadher

A set of ten new 2,3-diphenyl-6-sulfonamido quinoxaline derivatives was synthesized and screened for antimicrobial activity by disk diffusion method. Test derivatives R3, R5, R’’1 and R’’2 show promising results against bacterial strains S. aureus gram positive and E. coli gram negative organism with the concentration 1000 μg/mL in disk diffusion method. Rest of the derivatives show sensitivity against the same organisms. All the synthesized derivatives were confirmed by their spectral data.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Kavita Devi ◽  
Yumna Asmat ◽  
Sonika Jain ◽  
Swapnil Sharma ◽  
Jaya Dwivedi

Oxazolidinone, either mononuclear or condensed with other heterocyclics, has established its importance in medicinal chemistry. A variety of biological activities have been reported by oxazolidinone derivatives. The present work describes the synthesis of several oxazolidinone derivatives, 3-(2-(7-chloroquinoline-4-ylamino)ethyl)-2-imino-5-(4-chloro/nitro/methoxy benzylidene)oxazolidin-4-one 4(a–c) and 4-(2-(7-chloroquinolin-4-ylamino)ethyl)-2(4-chloro/nitro/methoxy-benzylidene)-1,6-diox-4,9-di-azaspiro[4,4]nonane-3,8-dione 5(a–c). Synthesized compounds (1, 3, 4a, 5a, and 5c) were screened against bacterial strains such asS. aureus(MTCC 96) andE. coli(MTCC119) and fungal strainsA. niger(MTCC 1344) andC. albicans(MTCC 871) compared with penicillin for bacteria and fluconazole for fungi as reference drugs by disk diffusion method. All synthesized compounds were identified by the means of IR, NMR, and MS.


Author(s):  
Hanan. M. Abobaker ◽  
Hamida. EL. Elsalhin

Cultures of the blue green algae (cyanobacteria) Anabaena circinalis were identified and isolated from freshwater and their antimicrobial effect was studied. The extract of A. circinalis was tested to   investigate its efficiency against four bacterial strains (Achromobacter xylosoxidans, Staphylococcus aureus, Escherichia coli, Shigella dysenteriae. Antimicrobial test was determined by disk diffusion method. Different concentrations of algal extracts (25, 50, 75 and 100%) were tested. Results showed that the highest level of antimicrobial activity was recorded against S. dysenteriae at 100% concentration followed by 25% extract concentration against the same bacteria. In comparison with two antibiotics Ampicillin (AMP), oxacilina (OXA), AMP was the most effective on S. dysenteriae followed by OXA. S. aureus and E. coli were resistant to both antibiotics while they were sensitive to A. circinalis extracts at even at low concentrations (25% and 50%). Thus the present study revealed that extracts of A. circinalis extract is would be a promising natural source, for novel antibiotics, hence worthy for more investigations.


Author(s):  
Mohamed Sabri Khelfaoui ◽  
Rayane Zeroug ◽  
Maroua Yousfi ◽  
Bouchra Satha

Background: Urinary tract infections (UTIs) are a serious world-wide health problem whose treatment becomes highly difficult due to the emergence of antibiotic-resistant bacterial strains. Aims: Herein, a retrospective study was conducted with the aim to determine the prevalence, the identification of the bacteria responsible of UTIs, and the antimicrobial resistance profile. Study Design: All Patient samples, including either external samples or samples taken from patients admitted to Public Hospital Establishment “Saad Guermech Saoudi Amar Hmaida” in Skikda-Algeria were used in this study for a period extending from January 2018 – March 2020. Methodology: The identification of bacterial strains and the antibiotic susceptibility testing was carried out using Analytical Profile index galleries (API) system and disk diffusion method. Results: Among the 1203 samples, 206 (17.12%) were positive, and 997 (82.88%) were negative for bacterial growth. Regarding the pathogenic strains, 26 (12.62%), and 180 (87.38%) were found respectively, Gram-positive and Gram-negative strains. Among the 180 Gram negative strains, 104 (57.83%) were reported in female patients, 68 (37.72%) were in male patients, and 8 (4.45%) whose gender was not mentioned. The most representative Gram-negative strains are Escherichia coli (E. coli) (43.33%), Klebsiella pneumoniae (K. pneumoniae) (13.33%), Proteus mirabilis (P. mirabilis) (7.77%), Enterobacter sp (E. sp) (6.66%), since the other strains were less frequent. Moreover, 6 bacterial strains belonging to 3 genera (Escherichia, Klebsiella, and Enterobacter) were ESBLs producers with an overall prevalence of 3.33% of pathogenic strains isolated from urine. ESBLs were produced in 4.00%, 5.88%, and 6.25% of E. coli, K. pneumoniae, and E. cloacae strains respectively. Conclusion: E. coli was found to be the most predominant strain, while most of the Gram- negative strains were highly resistant to Amoxicillin/clavulanic acid, Ampicillin, penicillin and tobramycin.


Author(s):  
Usha Masih

Bacterial foodborne diseases are caused by consumption of foods contaminated with bacteria or their toxins. This study evaluated antibacterial properties of Trachyspermum ammi Acetone, ethanol, methanol, cold water and hard water extracts of spice (Ajowan) seeds against four gram negative strains of pathogenic foodborne bacteria, E. coli O157:H7   ATCC 43888, ATCC 25922, ATCC 8739 and ATCC 43895 that cause infection and intoxication. E. coli ATCC 43888 was observed to be highly susceptible to all extracts of ajowan with absolute zones of inhibition in the range of 16mm – 23mm in diameter. This study demonstrated that spice extracts have antimicrobial activity against food-borne bacterial species and should be considered as potential antibacterial agents for addition to ready meals. The spice contain high amount of secondary metabolites due to these metabolites they have high antimicrobial activity and it can be used as good bio- preserver and it can also use for medicinal purpose.


2020 ◽  
Vol 7 (3) ◽  
pp. 463-468
Author(s):  
Hong Thien Van ◽  
Dang Gia Man Nguyen ◽  
Nguyen Tuong An Quynh ◽  
Van Son Le

In this study, the antibacterial activity of ethanolic extract from the leaves of four Rutaceae species, including Acronychia pedunculata, Clausena excavata, Glycosmis pentaphylla and Luvunga scandens, were performed using the agar disk diffusion method for the first time. The ethanolic extracts from the leaves of A. pedunculata and G. pentaphylla were able to resist against all six bacterial strains with zones of inhibition for Bacillus cereus (17.3±2.1 mm, 20.8±1.0 mm) Staphylococcus aureus (8.5±0.5 mm, 17.6±0.3 mm) Escherichia coli (16.7±2.1 mm, 15.3±1.2 mm), Pseudomonas aeruginosa (11.7±0.6 mm, 14.0±1.7 mm), Salmonella enteritidis (22.3±0.6 mm, 24.6±0.5 mm) and Salmonella typhimurium (9.5±0.9 mm, 8.3±0.6 mm). On the other hand, the ethanolic extract of C. excavata leaf was resistant to B. cereus (12.3±0.6 mm), S. aureus (11.6±0.5 mm), E. coli (11.5±2.1 mm), P. aeruginosa (10.6±0.3 mm) while B. cereus (8.2±0.3 mm), S. aureus (9.3±0.6 mm), E. coli (8.5±0.5 mm) and S. typhimurium (8.3±0.6 mm) were inhibited by the ethanolic extract of L. scandens leaf. This study could provide necessary information for further application of these species in medicine.


Author(s):  
Ganesamoorthy Thirunarayanan ◽  
R. Senbagam ◽  
M. Rajarajan ◽  
V. Manikandan ◽  
S. Balaji ◽  
...  

A series of ten substituted (E)-2-benzylidene-N-methylhydrazinecarbothioamides were synthesized from 4-methyl-3-thiosemicarbazide with substituted benzaldehydes. All the synthesized compounds were in good agreement with elemental and spectral data (UV, FT-IR, 1H NMR and 13C NMR). The assigned UV λmax (nm), IR νC=N (cm-1), NMR δ1H (ppm) CH=N and δ13C (ppm) C=N spectral data of (E)-2-benzylidene-N-methylhydrazinecarbothioamides correlated with Hammett constants using single and multi-regression analysis. From the results of correlation analysis substituent effects on the spectral data have been discussed. The antibacterial activity of (E)-2-benzylidene-N-methylhydrazinecarbothioamides have been studied with three Gram-positive pathogenic bacterial strains namely (B. subtilis, S. aureus and S. pyogens) and two Gram-negative strains (E. coli and P. aeruginosa). The antifungal activity of (E)-2-benzylidene-N-methyl hydrazones studied with three fungal species (A. flavus, A. niger, T. viride) using disk diffusion method. 


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