scholarly journals Complete microbiological analysis of citrus fruits and the effect of heat on microbial load & antimicrobial activity

2017 ◽  
Vol 7 (1) ◽  
pp. 28-32
Author(s):  
Sheikh Al Mamun ◽  
Farahnaaz Feroz
Keyword(s):  
Heat Treatment ◽  
Antibacterial Activity ◽  
Reducing Sugars ◽  
Antimicrobial Properties ◽  
Microbial Load ◽  
Microbiological Analysis ◽  
Citrus Fruits ◽  
Polymethoxylated Flavones ◽  
Staphylococcus Spp ◽  
Klebsiella Spp

Citrus fruits are very popular both for raw consumption as well as juices, jam and jelly. Besides the nutritional properties, citrus fruits exhibit some antimicrobial properties by containing polymethoxylated flavones, flavonoids, steroids, saponins, alkaloids, reducing sugars, terpenoids etc. But sometimes such fruits can be contaminated with bacteria which find their ways in the consumers causing different disease conditions. The current study revealed the microbial load of Lemon, Lotkone, Orange, Malta and Amoloki and the study showed complete absence of Klebsiella spp. and Escherichia coli. The highest total viable bacterial and fungal count was 4.2×104 cfu/g and 2.0×105 cfu/g respectively. Pseudomonas spp. was the highest predominating bacteria with lower degree of contamination by Listeria spp. and Staphylococcus spp. Applying heat at 60oC for 30 minutes, 1 hour and 2 hours proved the reduction of bacteria over time. Antibacterial activity after heat treatment for all cases (after 30 minutes, 1 hour and 2 hours). Antibacterial activity was lowest after 2 hours of heat treatment for amoloki and there was no such activity at all for Amra after 2 hours. Other citrus fruits surprisingly showed no antibacterial activity after heat treatment. Stamford Journal of Microbiology, Vol.7(1) 2017: 28-32

scholarly journals Microbiological analysis and determination of antibacterial activity of apple samples collected from local markets in Dhaka city, Bangladesh

2017 ◽  
Vol 6 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Sheikh Al Mamun ◽  
Kamal Kanta Das ◽  
Md Aftab Uddin
Keyword(s):  
Antibacterial Activity ◽  
Local Market ◽  
Microbiological Analysis ◽  
Dhaka City ◽  
Bacterial Isolates ◽  
Salmonella Spp ◽  
Shigella Spp ◽  
Viable Bacteria ◽  
Staphylococcus Spp

Present study attempted to detect the prevalence of contaminating microorganisms in 10 categories of local market apple samples commonly consumed in Dhaka city, Bangladesh. A significant number of total viable bacteria were quantified up to 106 cfu/g in these samples. Staphylococcus spp. was the predominant isolate within a range of 1.0×104– 3.2×106cfu/g whereas Escherichia coli, Klebsiella spp., Salmonella spp., Shigella spp., Pseudomonas spp. and Vibrio spp. were also quantified. Fungal contamination (within the range of 105 cfu/g – 107cfu/g) was also observed. Alarmingly most of the bacterial isolates present in the samples were proved to be multi-drug resistant. Antibacterial activity of the samples was tested against some common bacterial isolates but was found to be ineffective.Stamford Journal of Microbiology, Vol.6(1) 2016: 11-15

scholarly journals Synthesis and Antimicrobial Properties of Naphthylamine Derivatives Having a Thiazolidinone Moiety

Medicina ◽  
2011 ◽  
Vol 47 (6) ◽  
pp. 47
Author(s):  
Vilma Petrikaitė ◽  
Eduardas Tarasevičius ◽  
Alvydas Pavilonis
Keyword(s):  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Antifungal Activity ◽  
Inhibitory Concentration ◽  
Antimicrobial Properties ◽  
Microbiological Analysis ◽  
Antibacterial And Antifungal Activity ◽  
Antibacterial And Antifungal ◽  
New Compounds

Objective. The aim of this study was to evaluate the influence of pharmacophores having naphthylamine and nitro groups on the antimicrobial (antibacterial and antifungal) activity of thiazolidinone derivatives. Materials and Methods. The initial 5-substituted-2-methylmercaptothiazolidin-4-ones were subjected to S-demethylation to yield 2-amino-substituted thiazolidinones. 4-Nitro-1-naphthylamine, nitrofuran aldehydes, and nitrobenzene aldehydes were used as pharmacophoric compounds having amino or aldehyde groups. Antimicrobial (antibacterial and antifungal) activity of the new compounds was tested in vitro against bacterial cultures – Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae – and fungal cultures – Candida albicans, Candida glabrata, Candida krusei, Candida kefyr, Candida tropicalis, and Candida parapsilosis. Results. Microbiological analysis showed that all new thiazolidinone derivatives with nitronaphthylamine substituent possessed antibacterial and antifungal properties. New compounds 2a-b showed similar antibacterial activity in vitro against S. aureus and B. subtilis as aminopenicillins. The lowest antibacterial activity of all newly synthesized compounds was against capsule-forming bacteria K. pneumoniae and against gram-negative bacteria E. coli (minimum inhibitory concentration range, 500–1000 μg/mL). Conclusions. The minimum inhibitory concentration of naphthylamine derivatives varied in the range of 0.4–1000 μg/mL, and activity of some newly synthesized compounds was similar to the activity of aminopenicillins and fluconazole, an antifungal preparation. Based on the results, it is possible to separate the perspective group of potential antimicrobial compounds.

scholarly journals Microbiological analysis and detection of anti-bacterial activity of Centella asiatica and Aloe vera samples collected from different areas of Dhaka city, Bangladesh

2017 ◽  
Vol 6 (1) ◽  
pp. 39-43 ◽  
Author(s):  
Susmita Bhowmik ◽  
Runa Akter Chowdhury ◽  
Md Aftab Uddin
Keyword(s):  
Antibacterial Activity ◽  
Aloe Vera ◽  
Centella Asiatica ◽  
Bacterial Count ◽  
Microbiological Analysis ◽  
Dhaka City ◽  
Salmonella Spp ◽  
Fungal Load ◽  
Bacillus Spp ◽  
Klebsiella Spp

The present study was performed to detect the presence of contaminating microorganisms in two commonly available herbal samples (Centella asiatica and Aloe vera) collected from different areas of Dhaka city, Bangladesh and to assess their antibacterial activity. Out of twenty samples (having ten samples of each categories) studied; the range of total viable bacterial count was approximately 103 to 108 cfu/g. Presence of Staphylococcus aureus was found in all the samples, followed by Klebsiella spp. in 15 samples, Pseudomonas spp. in 14 samples, Bacillus spp. in 12 samples, Escherichia coli in 9 samples and Vibrio spp. in 7 samples. Salmonella spp. was detected in neither of the sample. 17 samples showed a high fungal load up to 107 cfu/g. Antibacterial activity of C. asiatica samples was demonstrated against eight laboratory isolates. Only four C. asiatica samples showed activity against Klebsiella spp. On the contrary, Aloe vera samples (12-14) showed antibacterial activity only against Staphylococcus spp.Stamford Journal of Microbiology, Vol.6(1) 2016: 39-43

scholarly journals Expiration Date of Ready-to-Eat Salads: Effects on Microbial Load and Biochemical Attributes

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 941
Author(s):  
Panayiota Xylia ◽  
George Botsaris ◽  
Panagiotis Skandamis ◽  
Nikolaos Tzortzakis
Keyword(s):  
Shelf Life ◽  
Foodborne Pathogens ◽  
Carbon Dioxide Production ◽  
Microbial Load ◽  
Expiration Date ◽  
Postharvest Management ◽  
Minimally Processed Vegetables ◽  
Yeasts And Molds ◽  
Staphylococcus Spp ◽  
Spoilage Microorganisms

When minimally processed vegetables reach their expiration date, expose an increased microbial load. This includes mainly spoilage microorganisms but also foodborne pathogens, thus affecting the quality and safety of highly consumed ready-to-eat salads. A total of 144 ready-to-eat salads from the Cypriot market were analyzed in an attempt to determine the effects of the expiration date on the microbial load and plant metabolic variables of the salads. Possible correlations between them were also investigated for the first time. Furthermore, the impacts of the season (winter, summer), salad producing companies and type of salad and/or their interactions with the tested parameters were investigated. Results revealed that the microbial load (mainly spoilage microorganisms, such as Pseudomonas spp., yeasts and molds) increased towards the end of the shelf life. The microbial load was differentiated among the five salad producers and/or the salad types, highlighting the importance of a common and safe sanitation-processing chain in the preparation of ready-to-eat salads. Summer was the season in which Escherichia coli counts were found to be higher for plain lettuce, while Staphylococcus spp. was increased numbers for the lettuce+endive/radicchio, lettuce+rocket and lettuce+chives type of salads. Additionally, an increased Staphylococcus spp. was observed for plain rocket salads in winter. All samples examined were found negative for Salmonella enterica and Listeria monocytogenes. Moreover, carbon dioxide production and damage indexes (hydrogen peroxide and lipid peroxidation) increased on expiration date on both winter and summer seasons, indicating plant tissue stress at the end of shelf life. These findings indicate that the expiration date and relevant shelf life of processed vegetables are important parameters to be considered when postharvest management is applied to these products, ensuring safety and quality.

scholarly journals An In Vitro Study on the Antimicrobial Properties of Essential Oil Modified Resin Composite against Oral Pathogens

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4383
Author(s):  
Barbara Lapinska ◽  
Aleksandra Szram ◽  
Beata Zarzycka ◽  
Janina Grzegorczyk ◽  
Louis Hardan ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Antimicrobial Agents ◽  
Resin Composite ◽  
Antimicrobial Properties ◽  
In Vitro Study ◽  
Diffusion Method ◽  
Oral Pathogens

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S.mutans and L.acidophilus, as well as antifungal effect on C.albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S.mutans and L.acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S.mutans. All tested EOs exhibited antifungal activity against C.albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S.mutans and C.albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L.acidophilus.

scholarly journals Emphasized Mechanistic Antimicrobial Study of Biofunctionalized Silver Nanoparticles on Model Proteus mirabilis

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Asra Parveen ◽  
Manjunath S. Yalagatti ◽  
Venkataraman Abbaraju ◽  
Raghunandan Deshpande
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Proteus Mirabilis ◽  
Reducing Sugars ◽  
Radical Scavenging ◽  
Human Pathogens ◽  
Antimicrobial Study ◽  
Synthetic Procedure ◽  
Dpph Method ◽  
The Stability

Antimicrobial study of biofunctionalized silver nanoparticles has been done with the emphasis on its mechanism on both gram positive and negative bacteria. The biofunctionalized silver nanoparticles are employed considering their importance in green chemistry with respect to easy synthesis, usefulness, and economic synthetic procedure involved. The stability of these nanoparticles was determined by zeta potential analyzer. The probable mechanism of antibacterial activity was performed on Proteus mirabilis by field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDAX) study which does not show the presence of silver. The free radicals generated by silver nanoparticles were responsible for lethal antibacterial activity by rupturing the cell surface which causes improper nutrient and signal supply. Free radical scavenging efficacy of silver nanoparticles was confirmed by 1,1-Diphenyl-2-picrylhydrazyl (DPPH) method. AgNP enhanced the membrane leakage of reducing sugars by destroying the proteins existing on the cell wall. These nanoparticles are found to be toxic against human pathogens and are highly effective on Staphylococcus aureus. The effect of silver nanoparticles is concentration dependent and independent of the type of strains used.

scholarly journals Microwave-Hydrothermal Rapid Synthesis of Cellulose/Ag Nanocomposites and Their Antibacterial Activity

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 978 ◽  
Author(s):  
Lian-Hua Fu ◽  
Qing-Long Gao ◽  
Chao Qi ◽  
Ming-Guo Ma ◽  
Jun-Feng Li
Keyword(s):  
Antibacterial Activity ◽  
Antimicrobial Properties ◽  
Silver Ions ◽  
Heating Time ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Human Beings ◽  
Microwave Hydrothermal ◽  
Wide Range

Silver-based antimicrobial nanomaterials are considered as the most promising antibacterial agents owing to their outstanding antimicrobial efficacy and their relatively low toxicity to human beings. In this work, we report on a facile and environment-friendly microwave-hydrothermal method to prepare cellulose/Ag nanocomposites using hemicellulose as the reductant. The influences of the microwave-hydrothermal heating time and temperature, as well as the hemicellulose concentration on the formation of cellulose nanocomposites, were investigated in detail. Experimental results indicated that the hemicellulose was an effective reductant for silver ions, with higher temperature and longer heating time favoring the formation of silver with higher crystallinity and mass content in the nanocomposites. Moreover, the antimicrobial properties of the as-prepared cellulose/Ag nanocomposites were explored using Gram-positive S. aureus ATCC 6538 and Gram-negative E. coli HB 101 by both disc diffusion method and agar dilution method, and the nanocomposites showed excellent antibacterial activity. These results demonstrate that the as-prepared cellulose/Ag nanocomposites, as a kind of antibacterial material, are promising for applications in a wide range of biomedical fields.

scholarly journals Assessment of Microbial Load of Un-pasteurized Fruit Juices and in vitro Antibacterial Potential of Honey Against Bacterial Isolates

2015 ◽  
Vol 9 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Muhammad Naeem Iqbal ◽  
Aftab Ahmad Anjum ◽  
Muhammad Asad Ali ◽  
Firasat Hussain ◽  
Shahzad Ali ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Viable Count ◽  
Fruit Juices ◽  
Microbial Load ◽  
Resistant Bacteria ◽  
Klebsiella Pneumonia ◽  
Street Vendors ◽  
Permissible Limits ◽  
Development Of Resistance

The development of resistance in bacteria against commonly used antibiotics/drugs is of considerable medical significance. Aim of this study was to determine the microbial load of un-pasteurized packed fruit juices sold in Lahore city and to determine antibacterial activity of five different honey samples against isolated bacteria. Unpasteurized fruit juice samples (n=60) were collected from street vendors. All the samples were subjected to Total viable count (TVC), Staphylococcal count (SC) and Coliform count (CC). One hundred and ten strains of bacteria were isolated from various fruit juices and identified on the basis of cultural characters, morphology and biochemical characters. Mean TVCs, SCs and CCs of juices (6.80±1.91, 5.45±1.06 and 3.25±1.25 log10 CFU/ml respectively) were non-significant with standard permissible limits (p<0.05). Among all the fruit juices, 66.66% of samples had TVC more than 4 log10 CFU/ml, 51.66% of samples had SC more than 3 log10 CFU/ml and 46.66% of samples had CC more than 2 log10 CFU/ml. Among the bacillus isolates purified, were Bacillus alvei, Bacillus subtilis, Bacillus polymyxa, Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumonia, Escherichia coli and Enterobecter. All five different types of honey samples used in this study showed antibacterial activity against B. alvei, B. polymyxa, B. subtilis and S. aureus and no activity against P. aeruginosa, K. pneumonia, Enterobecter and E. coli. It is concluded that microbial load in unpasteurized fruit juices is significantly higher than standard permissible limits which insinuates its possible role in spoilage and food borne illnesses. Periodic monitoring of packed fruit juices should be carried out to make them safe for consumption. Honey can be used as an alternative for treatment of various infections, especially those caused by antibiotic resistant bacteria.

scholarly journals Formulation and Evaluation of Antibacterial Creams and Gels Containing Metal Ions for Topical Application

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Mei X. Chen ◽  
Kenneth S. Alexander ◽  
Gabriella Baki
Keyword(s):  
Antibacterial Activity ◽  
Metal Ions ◽  
Copper Sulfate ◽  
Zinc Sulfate ◽  
Antimicrobial Properties ◽  
Multidrug Resistant ◽  
Synergistic Activity ◽  
Minimum Effective Concentration ◽  
Organoleptic Characteristics

Background. Skin infections occur commonly and often present therapeutic challenges to practitioners due to the growing concerns regarding multidrug-resistant bacterial, viral, and fungal strains. The antimicrobial properties of zinc sulfate and copper sulfate are well known and have been investigated for many years. However, the synergistic activity between these two metal ions as antimicrobial ingredients has not been evaluated in topical formulations. Objective. The aims of the present study were to (1) formulate topical creams and gels containing zinc and copper alone or in combination and (2) evaluate the in vitro antibacterial activity of these metal ions in the formulations. Method. Formulation of the gels and creams was followed by evaluating their organoleptic characteristics, physicochemical properties, and in vitro antibacterial activity against Escherichia coli and Staphylococcus aureus. Results. Zinc sulfate and copper sulfate had a strong synergistic antibacterial activity in the creams and gels. The minimum effective concentration was found to be 3 w/w% for both active ingredients against the two tested microorganisms. Conclusions. This study evaluated and confirmed the synergistic in vitro antibacterial effect of copper sulfate and zinc sulfate in a cream and two gels.

scholarly journals Microbiological analysis and sensitivity profile of Staphylococcus spp. in subclinical mastitis of dairy goats

2016 ◽  
Vol 68 (2) ◽  
pp. 336-344
Author(s):  
S.R.S. Salaberry ◽  
A.B.S. Saidenberg ◽  
E. Zuniga ◽  
F.F. Gonsales ◽  
P.A. Melville ◽  
...  
Keyword(s):  
Subclinical Mastitis ◽  
Economic Losses ◽  
Microbiological Analysis ◽  
Dairy Goats ◽  
Milk Samples ◽  
California Mastitis Test ◽  
Resistant Strains ◽  
Staphylococcus Spp ◽  
Sensitivity Profile

Subclinical mastitis in goats causes economic losses and risks to public health. Given the need for research that shows the most isolated staphylococci species and sensibility tests comparing the resistance between coagulase-negative (CNS) and positive Staphylococcus (CPS) goats with subclinical mastitis, the aim of this study was to identify the microorganisms isolated from milk samples of goats with subclinical mastitis, as well as define the staphylococci species and determine the sensitivity profile of Staphylococcus spp. to antimicrobials. To collect samples, tests were performed for mug of black background and California mastitis test (CMT), collecting milk from CMT positive animals. A total of 226 samples from seven herds of dairy goats was collected and forwarded to the laboratory, where they were seeded for the isolation of the microorganism and implementing the antibiotic sensibility test. Of these, 122 samples had bacterial growth and the most isolated staphylococci species were: S. epidermidis (24.55%), S. lugdunensis (15.40%) and S. intermedius (13.64%). Samples showed increased resistance to antimicrobials: penicillin (81.8%), oxacillin (60.0%) and ampicillin (55.5%). Greater sensitivity to: enrofloxacin (99.1%), erythromycin (98.2%), gentamicin (98.2%) and vancomycin (98.2%) were observed. The S. epidermidis showed higher antimicrobial resistance to amoxicillin and penicillin than S. lugdunensis and S. intermedius. Similar resistance in vitro between CNS and CPS was observed to most antimicrobials. It is important to control the overuse of antibiotics to prevent the emergence of resistant strains.

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