Investigation of the antimicrobial properties of nanoclay and chitosan based nanocomposite on the microbial characteristics of Gouda cheese

Author(s):  
Mojtaba Mohammadzadeh-Vazifeh ◽  
Seyed Masoud Hosseini ◽  
Ali Mohammadi ◽  
Mahdi Jahanfar ◽  
Hadi Maleki

  Background and Objectives: In recent years, active packaging has been introduced as a new method to better preserve food. Chitosan and nanoclay have been used for preparation of an active nanocomposite with respect to their antimicrobial properties to investigate its effects on the microbial limitation in Gouda cheese. Materials and Methods: Nanoclay film, chitosan film, chitosan-based nanocomposites and nanoclay-based nanocompos- ites were prepared and their antimicrobial properties were evaluated to the microbial limitations of Gouda cheese con- sist of coliforms, Escherichia coli, Salmonella spp., coagulase-positive Staphylococcus, mold and yeast by agar diffusion method. Results: The results indicated, the best antimicrobial effect belonged to nanocomposite film with the composition of chitosan 3 wt% by adding nanoclay 1 wt%, which can prevent microbial characteristics of Gouda cheese. Conclusion: The chitosan and nanoclay nanocomposite had excellent antibacterial activity and performed well against microbial limitations (coliforms, E. coli, Salmonella spp., coagulase-positive Staphylococcus, mold and yeast) of Gouda cheese. Therefore, the nanocomposite may be possibly used as a surface coating in addition to Gouda cheese as well as sim- ilar cheeses and other food to enhance microbial characteristics and extend shelf life.

2020 ◽  
Vol 307 ◽  
pp. 217-222 ◽  
Author(s):  
Maishara Syazrinni Rooshde ◽  
Wan Rafizah Wan Abdullah ◽  
Amie Zaidah Amran ◽  
Noradhiha Farahin Ibrahim ◽  
Fazilah Ariffin ◽  
...  

Biofouling and biofilms exist as ubiquitous, undesirable accumulation of flora and fauna upon a given substrate when being immersed into an aquatic medium. Therefore, a novel antifouling based materials with the incorporation of nanotechnology has been developed for the prevention of biofouling in its initial stage through photocatalytic treatment. This study investigated the antimicrobial properties of photoactive Cerium (Ce) doped ZnO powder and explores its potential properties for future antifouling application. ZnO nanoparticles was doped with 0.4 mol% Ce was synthesized through the combination of modified citrate gelation technique and solid state sintering. The successful preparation of Ce doped ZnO was confirmed by XRD and SEM. The antimicrobial activity of Ce doped ZnO against E. coli and S. aureus was determined through antibacterial susceptibility test by agar well diffusion method whilst its photocatalytic inactivation efficiency against selected bacteria was analysed through photodegradation testing under UV light irradiation. The findings demonstrated that the synthesized Ce doped ZnO powder exhibited antibacterial effect against Gram-positive bacteria (S. aureus) and excellent photocatalytic efficiency to inactivate both Gram-negative (E. coli) and Gram-positive (S. aureus). 2 g/L of Ce doped ZnO catalyzed the 100% disinfection of both bacteria in 180 min of UV light exposure. Thus, this proved that Ce doped ZnO powder has the potential as efficient antifouling agent.


2020 ◽  
Vol 6 (1) ◽  
pp. 13
Author(s):  
Nelson Phiri ◽  
Geoffrey Mainda ◽  
Mercy Mukuma ◽  
Ntazana N. Sinyangwe ◽  
Luke J. Banda ◽  
...  

Objective: Salmonella species and Escherichia coli are major bacterial enteropathogens of worldwide public health importance that cause devastating foodborne diseases, thereby contributing to increased human morbidity and mortality. Both pathogens have also been found to contribute towards the spread of antimicrobial resistance through the food chain, especially in poultry. This study aimed to determine the occurrence of antibiotic-resistant Salmonella spp. and E. coli in broiler chickens at farm level, abattoirs, and open markets in selected districts of Zambia.Methods: A cross-sectional study was undertaken in seven districts of Zambia to determine the resistance profiles of Salmonella spp. and E. coli obtained from broiler chickens at farms, abattoirs, and open markets. A total of 470 samples were collected which include; litter, cloacal swabs, and carcass swabs. Samples were inoculated into buffered peptone water and incubated for 24 hours then sub-cultured onto MacConkey and Xylose Lysine Deoxycholate agar plates. Identification of Salmonella spp. and E. coli was done using the API-20E kit and confirmation by 16S rDNA sequencing. Confirmed isolates were tested against a panel of 09 antibiotics using the Kirby-Bauer disc diffusion method and interpreted according to the Clinical Laboratory Standards Institute guidelines. Data analysis of the antibiotic sensitivity test results was done using WHONET 2018 software.Results: Overall, 4 Salmonella spp. and 280 E. coli were isolated. One of the Salmonella spp. was resistant to ampicillin (25%), amoxicillin/clavulanic acid (25%), and cefotaxime (25%). E. coli antibiotic resistance was highest to tetracycline (81.4%) and 100% susceptibility to imipenem. The antibiotic susceptibility profile revealed 75.7% (237/280) multidrug-resistant (MDR). The highest MDR profile was observed in 8.2% (23/280) isolates in which 6 out of the 9 classes of antibiotics tested were resistant. Out of the 280 isolates, 11.4% (32/280) exhibited Extensive Drug resistance (XDR).Conclusion: The study found antimicrobial resistance to E. coli and Salmonella spp. in market-ready broiler chickens which were resistant to important antibiotics and is of public health concern.


2017 ◽  
Vol 8 (2) ◽  
pp. 101-106
Author(s):  
Ruth Elenora Kristanty ◽  
Junie Suriawati ◽  
Priyanto Dwi Nugroho

Honey is a highly nutritious food product and consumed by almost all the population in the world. It has a function as an antimicrobial. Staphylococcus aureus (S. aureus) is a common Gram-positive bacteria in food and Escherichia coli (E. coli) is a Gram-negative bacteria that often appears in environmental sanitation issues that both can cause infectious diseases.  Some infectious diseases can be treated with antimicrobials such as honey. The purpose of this study was to test the antimicrobial effects on honey products distributed in Pasar Minggu area. The antimicrobial effect test was performed in vitro using agar diffusion method by measuring the inhibition zone formed where the bacteria growth was inhibited by the presence of sample. The concentration of samples were 25%, 50%, 75%, and 100% (not diluted) and as aquades control. The results showed that honey tested with various dilution concentrations resulted inhibition zone and. The higher concentration of the inhibited zone zone showed antimicrobial activity against S. aureus and E. coli.


2020 ◽  
Vol 21 (4) ◽  
Author(s):  
Siti Samiyarsih ◽  
NUR FITRIANTO ◽  
ELLY PROKLAMASININGSIH ◽  
JUWARNO ◽  
JUNI SAFITRI MULJOWATI

Abstract. Samiyarsih S, Fitrianto N, Proklamasiningsih E, Juwarno, Muljowati JS. 2020. Phytochemical diversity and antimicrobial properties of methanol extract of several cultivars of Catharanthus roseus using GC-MS. Biodiversitas 21: 1332-1344. Catharanthus roseus (L.) G is an important medicinal plant to evaluate the possibility of novel pharmaceuticals since most of the bacterial pathogens are developing resistance against antibiotics. This research aimed to determine the phytochemical diversity of methanol extract of eight cultivars of C. roseus and to evaluate for possible antimicrobial (antifungal and antibacterial) activities. It is the first research to compare phytochemicals and antimicrobial potential among C. roseus cultivars. The compound obtained was screened by Gas Chromatography-Mass Spectrometry (GC-MS) method. While agar-well disc diffusion method was employed to measure antimicrobial activity against Escherichia coli, Staphylococcus aureus, Aspergillus flavus and Aspergillus niger. Based on GC-MS analysis, a total of 18 significantly different metabolite compounds. The abundances of phytochemical compounds (18 classes total) in each cultivar were Dark Pink (66%), Pink (50%), Purple Pink (44%), Pale Pink (27%), White (44%), Milky White (50%), Whitish pink (50%) and Pinkish Red (55%). The leaves extracts showed antimicrobial activity with inhibition zones ranging from 6.40-22.00 mm and 3.35-8.20 mm, respectively. The best antimicrobial activity against E. coli, S. aureus, A. flavus, and A. niger with the zone of inhibition 16.10±1.67 mm, 22.00±0.33 mm, 6.05±0.67 mm and 8.20±0.50 mm respectively by Dark Pink cultivar.


Author(s):  
Ojah Emmanuel Onah ◽  
Kachi Jolly Babangida

Background: Micro-organisms are responsible for the transmission of a large number of diseases. It is hard to comprehend the amount of diseases, deaths and economic losses caused by micro-organisms alone. Plants are good sources of eco-friendly and readily available antimicrobial agents. Purpose: The aim of this study was to evaluate the chemical constituents and antimicrobial characteristics of three fractions from ethnomedicinal Icacina trichantha. Oliv. (Icacinaceae).Methods: Methanol extract from Icacina trichantha. Oliv was obtained by maceration and fractionated successively using hexane, and ethyl acetate. The antimicrobial properties of Icacina trichantha. Oliv was assessed using agar cup diffusion method on MRSA, P. aeruginosa, S. typhi, C. krusei, S. dysenteriae, S. pyrogenes, E. coli, K. pneumoniae, C. albicans, and C. tropicalis. Phytochemical screening on fractions was also evaluated using standard methods.Results: Phytochemical screening on fractions revealed the presence of saponins, alkaloids, steroids, tannins, and glycosides. Agar diffusion assay on fractions showed growth inhibitory effect on all the organisms except P. aeruginosa, S. typhi, and C. tropicalis. The MIC revealed that n-hexane fraction was active against MRSA, S. pyrogenes, E. coli, K. pneumonia, C. albicans and C. krusei at 10 mg/mL while S. dysenteriae was active at 5 mg/mL. The ethyl acetate fraction was active against all the organisms at a concentration of 5 mg/mL except P.aeruginosa, S.typhi and C.tropicalis. Methanol fraction showed activity of 5 mg/mL against MRSA, S. pyrogenes, E. coli, S. dysenteriae, C. albicans and C. krusei except for K. pneumoniae with activity at 10 mg/mL. Minimum bactericidal concentration/fungicidal concentration MBC/MFC evaluated on the n-hexane fraction revealed that MRSA, S. pyrogenes, E. coli, K. pneumoniae, S. dysenteriae, C. albicans, and C. krusei were activeat 20 mg/mL, while the ethyl acetate fraction had MBC/MFC of 10 mg/mL against all the organisms except P. aeruginosa, S. typhi, C. tropicalis. Methanol extract had MBC/MFC of 10 mg/mL against MSRA, E.coli and S. dysenteriae whereas S. pyrogenes, K. pneumoniae, C. albicans and C. krusei had MBC/MFC at 20 mg/mL.Conclusion: Icacina trichantha. Oliv. contain constituents with concentration dependent antimicrobial properties based on type of organism. The plant could be useful in the prevention and treatment of multi-resistant disease causing microorganisms.


2018 ◽  
pp. 1-10

Dental caries is the most contagious disease throughout the world. In the present study, a total of 100 dental caries patients were selected and samples from these patients were collected through sterile pincers for microbiological examination. A total of 9 different pathogenic bacterial isolates were identified through conventional culturing technique and among them maximum number of occurrence was by Salmonella spp (26.13%), followed by E. coli (17.39%), Proteus spp (17.39%), Shigella spp (8.69%), Pseudomonas spp (8.69%), Vibrio spp (8.69%), Enterobacter spp (4.34%), Yersinia spp (4.34%) and S. mutans (4.34%). Furthermore, antibiotic susceptibility tests were performed by 9 different commercially available antibiotics i.e. vancomycin, erythromycin, clindamycin, amoxicillin, tetracycline, rifampicin, ampicillin, ticarcillin and metronidazole/silver sulphadizine. Kirby Bauer disc diffusion method was used against test organisms and it was observed that all these antibiotics expressed significant activity against greater part of test organisms but few of them showed resistance to metronidazole/silver sulphadizine. In addition to this, different toothpastes encoded as TP-1, TP-2, TP-3, TP-4 and TP-5 were used at a concentration of 20 mg/mL in order to evaluate their activity against test organisms and it was observed that all these toothpastes showed significant activity against isolated bacteria. It was concluded that all these toothpastes contained fluoride which supports to avoid tooth decay and promote minty fresh breath. Furthermore, it was recommended that avoid usage of too much sweets, chocolates, candies especially in children/adults, and there must be a proper use of toothpastes twice a day at every stage of life. Keywords: Dental Caries, Pathogenic Bacteria, Antibiotics, Fluoride Toothpastes


2018 ◽  
Vol 16 (2) ◽  
pp. 147-157 ◽  
Author(s):  
Wilfred O Obonga ◽  
Philip F Uzor ◽  
Emmanuel O Ekwealor ◽  
Sampson C Nwabuko

The present study was aimed at a comparative study of the phytoconstituents, antioxidant and antimicrobial properties of four medicinal plants, Ficus capensis, Aristolochia ringens, Albizia zygia and Lannea welwitschii. The leaf of F. capensis and stem bark of A. ringens, A. zygia and L. welwitschii were extracted using methanol. Phytochemical analysis was done spectrophotometrically. Three in vitro antioxidant tests-hydrogen peroxide (H2O2), nitric oxide (NO) and 2, 2-diphenyl-1-picrylhydroxyl (DPPH) scavenging models were employed. Antimicrobial test was done by agar diffusion method against E. coli, Staphylococcus aureus, Klebsiela pneumonia, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhi, Candida albicans and Aspergittus spp. Phytochemical analysis revealed that the most abundant phytoconstituents were flavonoids (F. capensis and A. zygia), reducing sugar, terpenoids, alkaloids and tannins. In the antioxidant models, A. zygia was found to produce the least IC50 in two of the models (NO and DPPH). Results of the antimicrobial tests showed that A. zygia showed a broader spectrum of activity than other plants. This study has shown that these plants possess antioxidant and antimicrobial activities which further justify their usage in traditional medicines. A. zygia featured prominently in these activities. Also flavonoids could be responsible for the bioactivities of these plants.Dhaka Univ. J. Pharm. Sci. 16(2): 147-157, 2017 (December)


Author(s):  
Courage Kosi Setsoafia Saba ◽  
Akosua Bonsu Karikar ◽  
Enoch Yeleliere ◽  
Patrick Takyi ◽  
Stephen Wilson Kpordze

Microbial contamination of vended foods are of public health importance due to the potential of becoming a reservoir of foodborne pathogens and resistant strains of bacteria. This study looked at the presence of pathogenic bacteria in a popular Ready-To-Eat (RTE) traditional food, Fufu in Ghana. Sixty (60) Fufu samples were obtained from various food joints categorized as Opened, Semi-closed and Closed or Restaurants. Samples were processed and analyzed using standard bacteriological methods. The susceptibility profiles of the isolates were obtained by using the Kirby-Bauer disk diffusion method with the EUCAST guidelines with the five antibiotics. Prevalence of E. coli was 85% and Salmonella species was 68%. Microbial count of isolated E. coli ranged from 0 to 3×106 cfu/ml. There were no significant differences (p>0.05) among the different modes of operations. Fufu samples from Opened, Semi-closed and Closed joints were respectively contaminated with E. coli and Salmonella species as follows: 92%, 76%; 80%, 60% and 80%, 65%. The Salmonella species showed highest resistance to erythromycin (58.5%) and E. coli species were commonly resistant to Ceftazidime (88.2%) and Ceftriaxone (94.1%). All isolates were susceptible to nitrofurantoin. Multidrug resistance was detected among 27.5% of E. coli strains and 14.6% of Salmonella species. Fufu from the different eating joints in the Tamale Metropolis were substantially contaminated with multidrug resistant pathogens. The study recommends surveillance studies of resistant pathogens in foods, increased education and training of food vendors on sanitation, food handling and safety practices in the region.


2016 ◽  
pp. 21-24
Author(s):  
Md Kamruzzaman Siddiqui ◽  
Nazma Khatoon ◽  
Pravas Chandra Roy

Antimicrobial resistance in both pathogenic and commensal bacteria is increasing steadily. Failure of antibiotic resistant bacteria containment is responsible for this expansion. Healthcare effluent acts as the store house of harmful infectious pathogens. Potential health risk includes spreading of diseases by these pathogens and wide dissemination of antimicrobial resistance genes. The present study was carried out to investigate the multiple-drug resistance among the bacterial strains that were isolated and identified from the effluents of Jessore Medical College Hospital & Jessore Queen’s hospital private limited. Identified bacteria were E. coli , Klebsiella spp., Enterobacter spp., Proteus vulgaris and Salmonella spp.. Occurrence of E. coli and Enterobacter spp. were found to have the highest percentages and present in majority of the samples. The identified organisms antibiotic resistant pattern were analyzed by agar disc diffusion method against 6 antibiotics. Results of antibiotic susceptibility test showed that all of the isolates were multi-drug resistant (e”4). From the study, we observed that 75% of the isolates were resistant to amoxicillin, followed by Ampicillin (64%), Chloramphenicol (31%), Gentamycin (29%), Nitrofurantoin (27%) and least resistant being Ciprofloxacin 23%. Among the isolates Salmonella spp. were showed highest rate of resistance against all the used antibiotics. The result denotes that, the identified bacteria have been well exposed to the tested antimicrobials and they have established mechanisms to avoid them. Therefore, proper waste water treatment plant should be established to diminish the risk of disseminating multiple drug resistant microorganisms for the safeguard of public health.Bangladesh J Microbiol, Volume 32, Number 1-2,June-Dec 2015, pp 21-24


2003 ◽  
Vol 9 (2) ◽  
pp. 85-88 ◽  
Author(s):  
G. Özkan ◽  
O. Sağdiç ◽  
M. Özcan

The antimicrobial effect of 11 selected Turkish spice essential oils was investigated against seventeen pathogenic bacteria. The antimicrobial activity of the essential oils of six spices (cumin, fennel, laurel, mint, marjoram, oregano, pickling herb, sage, savory, thyme (black) and thyme) was tested at four concentrations (0.2, 0.4, 1 and 2%) on various microorganisms ( E. aerogenes, E. coli, E. coli O157:H7, K. pneumoniae, P. vulgaris, S. enteritidis, S. gallinarum, S. typhimurium, S. aureus, Y. enterocolitica, A. hydrophila, C. xerosis, M. luteus, M. smegmatis, E. feacalis, P. aeruginosa and P. fluorescens). All preparations showed antibacterial activity against at least one or more bacteria. The inhibitory effect of the essential oils was evaluated through paper disc diffusion method. In general, the essential oils at 1 and 2% levels were effective. The most active essential oils were marjoram, thyme and oregano. According to the results, the studied essential oils potentially might be used as antibacterial agents to prevent the spoilage of food products, although further research is needed.


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