scholarly journals The synergistic bactericidal effects of bacteriocin and pressurization against E.coli O157:H7 in raw milk

2014 ◽  
Vol 38 (1) ◽  
pp. 15-23
Author(s):  
Najim Hadi Najim
Keyword(s):  
Antimicrobial Activity ◽  
Raw Milk ◽  
Inhibition Zone ◽  
Latex Agglutination ◽  
Pressure Level ◽  
Nutrient Broth ◽  
Whole Milk ◽  
Test Kit ◽  
Bactericidal Effects ◽  
Antimicrobial Effectiveness

Colonies of E.coli O157:H7 were isolated from 35 raw milk sample and their identification were confirmed based on biochemical reactions and both cultural and serological characteristics. Presumptive E.coli O157:H7 isolates obtained by selective plating on both CT-SMAC and Chromogenic agars were further tested serologically for the presence of both O157 and H7 antigenes using the commercial available latex agglutination test kit. The unhygienic practices in the production of milk in Al-Thahab Al- Abiedh , Abu-Graib, Al-Zedan and Khan Dharie were reflected on the highest significant (p<0.01)prevalence level of contamination with E.coli O157:H7 that appeared to be 80%, 80%, 60% and60% respectively. Homogenization pressure of 1000 psi and 2000 psi for five passes had significantly (p<0.05) influenced the inactivation degree of E.coli O157:H7 in both whole milk and nutrient broth. Milk homogenized at a pressure level of 3000 psi for three passes and 4000 psi for two passes resulted in a further increase of the antimicrobial effectiveness and produced an additional significant (p<0.05) reduction of E.coli O157:H7. Complete elimination (inactivation) of viable E.coli O157:H7 was achieved when cultured whole milk was homogenized at pressure level of 5000 psi for a single pass. Agar well diffusion bioassay was used for the evaluation of antimicrobial activity of the crude bacteriocin produced by L.acidophilus LA-K against E.coli O157:H7. Enterohaemorrhagic E.coli O157:H7 expressed its resistance to the crude bacteriocin since it did not show any inhibition zone around each well treated with bacteriocin. The average diameters of the inhibition zones of crude bacteriocin against stressed E.coli O157:H7 by pressurization at 4000 psi, 3000 psi, 2000 psi and 1000 psi were 14 mm, 12mm, 10mm and 8mm respectively. The homogenization pressure level (moderate or high) had significantly (p<0.05) influenced the inactivation degree of the crude bacteriocin against the stressed E.coli O157:H7 by pressurization. Quantitative measurement of crude bacteriocin antimicrobial activity was determined by using photometric or turbidometric method. The results revealed that no growth of stressed E.coli O157:H7 with no visible turbidity in the nutrient broth with bacteriocin that diluted to 1/2, 1/4 and 1/8 were observed. Bacteriocin that diluted to 1/8 which resulted in no visible turbidity after overnight of incubation at 37C° and gave an optical density reading of 1.448.

scholarly journals The synergistic effects of Lactobacillus acidophillus ROO52 and Lactobacillus bulgaricus LB-12 bacteriocins against E.coli O157 :H7 in milk

2014 ◽  
Vol 38 (2) ◽  
pp. 35-40
Author(s):  
Zina Saab Khudhir
Keyword(s):  
Lactobacillus Acidophilus ◽  
Synergistic Effects ◽  
Antimicrobial Effect ◽  
Average Diameter ◽  
Raw Milk ◽  
Inhibition Zone ◽  
Latex Agglutination ◽  
Lactobacillus Bulgaricus ◽  
Milk Samples ◽  
Test Kit

        The aims of this study to evaluate the antibacterial potential of standard strains (Lactobacillus acidophilus ROO52 and Lactobacillus bulgaricus LB-12) that produce bacteriocins against E.coli O157:H7 in raw milk.  Thirty raw milk samples randomly were collected weekly different markets of Baghdad city in order to investigate the prevalence of E.coli O157:H7 in milk. The prevalence of  E.coli O157:H7 in raw milk samples was  6 out 30 (20%) by using the modern chromogenic media with serological latex agglutination test kit. The average diameter of the inhibition zone of crude bacteriocin against  E .coli O157:H7 by using combination of 1:1 (v/v) of the Lactobacillus acidophillus ROO52 and  Lactobacillus bulgaricus LB-12was (14mm) ,while that produced by bacteriocins of Lactobacillus acidophillus ROO52 and  Lactobacillus bulgaricus LB-12  independently were 16 and 12mm respectively .L. delbrucekii ssp bulgaricus showed significantly (P<0.05) low antimicrobial effect against E.coli O157 :H7 .While the strongest antimicrobial effect was shown by Lactobacillus acidophilus ROO52. The bacteriocins of the reference strains used in this study did not result in an increase in inhibition when used in combination of 1:1 (v/v).

scholarly journals The antibacterial activity of bacteriocin produced by Lactobacillus acidophilus isolates against sensitive reference strain Lactobacillus acidophilus R0052 and its stability to different pH, heating and storage temperatures

2012 ◽  
Vol 36 (0E) ◽  
pp. 274-279
Author(s):  
Najim Hadi Najim
Keyword(s):  
Antimicrobial Activity ◽  
Lactobacillus Acidophilus ◽  
Storage Temperature ◽  
Inhibition Zone ◽  
Antimicrobial Activities ◽  
Sensitive Strain ◽  
Heat Stable ◽  
Soft Cheese ◽  
And Storage ◽  
Antimicrobial Effectiveness

Two isolates of Lactobacillus acidophilus were isolated from locally homemade soft cheese and identified in accordance with their main features as described by bergeys manual of determinative bacteriology .Agar well diffusion bioassay was used for the evaluation of antimicrobial activity of cell free supernatant (culture filtrates) of Lactobacillus acidophilus isolates against the sensitive strain Lactobacillus acidophilus R0052 and the diameter of the inhibition zone was proportional to the bacteriocin concentration. The antimicrobial activity of the bacteriocin was proportional to the reciprocal of the highest dilution factor producing a detectable zone of inhibition . The storage temperature of the crude bacteriocin had a significant(P˂ 0.01) effect on its potency against the sensitive strain .The potential of the antimicrobial activities of the crude bacteriocin that was stored for 10 days at refrigeration temperature (4°C) was significantly (P˂ 0.01) higher than that stored at room temperature. The antimicrobial effectiveness of the crude bacteriocin was heat stable and retaining 100% of its activity after its exposure to 60 °C & 80°C for 10 minutes .Boiling of the crude bacteriocin for 30 minutes had significantly (P˂ 0.01) decreased its potency to 0% .The potency of the crude bacteriocin was stable after four hours of exposure to both neutral (pH7) and acidic (pH4) conditions but was inactivated at alkaline (pH9) condition.

Green Synthesis of Silver Nanoparticles by Allamanda cathartica L. Leaf Extract and Evaluation for Antimicrobial Activity

2013 ◽  
Vol 6 (4) ◽  
pp. 2260-2268
Author(s):  
M. Linga Rao ◽  
Bhumi G ◽  
Savithramma N
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Fusarium Species ◽  
Inhibition Zone ◽  
Fungal Species ◽  
Green Technology ◽  
Metallic Silver ◽  
Synthesis Of Nanoparticles ◽  
Aqueous Leaf Extract

Silver nanoparticles (SNPs) exhibit tremendous applications in medicine as antimicrobial agent.  The use of different parts of plants for the synthesis of nanoparticles is considered as a green technology as it does not involve any harmful chemicals.  In the present study, we report a rapid biosynthesis of silver nanoparticles from aqueous leaf extract of medicinal plant Allamanda cathartica.  The active phytochemicals present in the plant were responsible for the quick reduction of silver ion to metallic silver nanoparticles. The reduced silver nanoparticles were characterized by using UV-Vis spectrophotometry, Scanning Electron Microscope (SEM), Energy Dispersive Analysis of X-ray (EDAX) and Atomic Force Microscopy (AFM).  The spherical shaped silver nanoparticles were observed and it was found to 19-40 nm range of size.  These phytosynthesized SNPs were tested for their antimicrobial activity and it analyzed by measuring the inhibitory zone. A. cathartica aqueous leaf extract of SNPs showed highest toxicity to Pseudomonas followed by Klebsiella, Bacillus and E. coli and lowest toxicity towards Proteus. In fungal species, highest inhibition zone was noted against Rhizopus followed by Curvularia, Aspergillus flavus and Aspergillus niger and minimum inhibition zone was observed against Fusarium species.  These results suggest a promising potential of Indian plant-based green chemistry for production of SNPs for biomedical and nanotechnology applications.

Increased Sensitization of Shrimp Microflora to Hypochlorite following a Sodium Bisulfite Dip1

1984 ◽  
Vol 47 (5) ◽  
pp. 375-377 ◽  
Author(s):  
MARIA L. PYLE ◽  
JOHN A. KOBURGER
Keyword(s):  
Antimicrobial Activity ◽  
Synergistic Effect ◽  
Bacterial Load ◽  
Sodium Bisulfite ◽  
Microbial Flora ◽  
Sequential Treatment ◽  
Antimicrobial Effectiveness ◽  
Iced Storage

Various concentrations of hypochlorite (12.5 to 200 ppm) and sodium bisulfite (0.15 to 2.50%) applied singly and as successive dips were compared for their effect on the microbial flora of shrimp. It was found that sodium bisulfite exhibited antimicrobial activity at all concentrations tested, with a 50% reduction in bacterial numbers at a concentration of 2.5%. Hypochlorite reduced the bacterial load 75% at a concentration of 200 ppm. Under certain conditions a sequential treatment of shrimp with bisulfite, followed by a hypochlorite dip, significantly increased the antimicrobial effectiveness of the hypochlorite. This synergistic effect, however, was not apparent on shrimp following 24 h of iced storage.

scholarly journals Antibacterial activity of ginger extracts on bacteria isolated from digestive tract infection patients attended Muhoza Health Center

2020 ◽  
Vol 11 (2) ◽  
pp. 35-41
Author(s):  
Callixte Yadufashije ◽  
Adolyne Niyonkuru ◽  
Emanuel Munyeshyaka ◽  
Sibomana Madjidi ◽  
Joseph Mucumbitsi
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Tract Infection ◽  
Health Center ◽  
Digestive Tract ◽  
Inhibition Zone ◽  
Ginger Extract ◽  
E Coli ◽  
Shigella Spp ◽  
Stool Samples

Background: Ginger (Zingiber officinale) has been used for long time due to its potential antimicrobial activity against diversity of microbial pathogens. Aims and Objectives: The study was carried out to investigate the bacteria pathogens found in digestive tract infections and assess antimicrobial activities of ginger extract to identified bacteria. Materials and Methods: Bacteriological studies were carried out on stool samples from 30 patients attending Muhoza health center. Different types of bacteria were isolated from stool samples of digestive tract infection patients by using various methods such culture, biochemical test and antimicrobial activity of ginger extracts was analyzed at INES-Ruhengeri in clinical microbiology laboratory. Results: Study findings showed isolated bacteria and antibacterial activity of Ginger. Isolated bacteria and their percentages including Escherichia coli (46.6%) which is the predominant isolated bacteria, Salmonella species (33.33%), Enterobacter spp (10.0%), Shigella spp (6.6%) and Citrobacter (3.33%) which is the least isolated bacteria. Antibacterial activity of ginger was seen on isolated bacteria, as ethanol and methanol were used for ginger oil extraction, the antibacterial activity of ginger extracts using ethanol was seen on isolated bacteria such us Citrobacter spp with 14 mm of inhibition zone, Shigella spp with 12 mm, Salmonella with 11.1 mm, E. coli with 9.5 mm and Enterobacter spp which was seen to be resistant to ginger extract using ethanol with 0.66mm of inhibition zone. For methanol extracts antibacterial activity was seen as follows: Citrobacter spp at 12 mm, Shigella spp at 11 mm, E. coli at 8 mm, salmonella spp at 6.1 mm, and Enterobacter spp with 5 mm. Enterobacter spp was seen to be the most resistant bacteria in both extracts. Conclusion: Ginger has shown to have an antibacterial activity on bacteria isolated from digestive tract infected patients. It can be used as a medicine to treat these infections. Number of researches should be done to be sure on this reality of antibacterial activity of ginger.

scholarly journals Antimicrobial Activity of Coriander sativum

2021 ◽  
pp. 74-81
Author(s):  
Samina Amin Qurban Ali ◽  
Arif Malik
Keyword(s):  
Antimicrobial Activity ◽  
Antioxidant Activity ◽  
Essential Oils ◽  
Aspergillus Flavus ◽  
Food Additives ◽  
Inhibition Zone ◽  
Microbial Pathogens ◽  
Bacterial Strains ◽  
High Concentration ◽  
Natural Oils

The increasing rate of drug-repellent pathogens and poisonousness of existing antiseptic compounds has strained attention toward activity of antimicrobial products which are natural. Main purpose of this research was to assess antimicrobial activity of seeds and leaves of Coriandrum sativum’s essential oil, antioxidant, antimicrobial activity and chemical composition of Coriandrum sativum’s ethanol extracts and essential oils. Numerous approaches were used in reviewing the antioxidant activity such as, p-anisidine test – malonaldhyde, DPPH and peroxide value. Antimicrobial activity of the extracts towards six microbial strains; two bacterial strains (Salmonella typhi and Staphylococcus aureus), one yeast (Candida tropicals) and three fungal strains (Aspergillus flavus, Mucor sp and Emericella nidulans) was assessed by determination of inhibition zone and count of bacteria, yeast and spares of fungus. The antimicrobial mechanisms found in these essential oils have been explained on the basis of their content in natural compounds such as carvacrol, thymol, p-cymene and c-terpinene, among others. Although these two essential oils have received much attention, scientists working in the fields of biomedicine and food science are paying increasing attention to a wider variety of aromatic natural oils in an effort to identify original and natural applications for the inhibition of microbial pathogens. In conclusion, utilization of coriander or their components as food additives will increase the antioxidant and the antimicrobial potential of the food which prevent food deterioration and improve the shelf-life of food beside its nutritional value. The results revealed that the leaves extracts have high levels of phenolics than the seeds extract. Concerning antioxidant activity, significant decreases (p>0.001) were observed in peroxide, P- anisidine and TBA values as compared to control oil. On the other hand, scavenging activity % of the four extracts on DPPH radical were higher than that of butylated hydroxyl toluene (BHT) especially with high concentration (1000 μg/ ml). Regarding antimicrobial activity, the results showed that the extract of coriander seeds has the highest reduction percent in growth of all the examined microorganisms. The result also revealed that Mucor sp was resistant to the action of parsley extracts while Aspergillus flavus has the highest resistance against coriander extracts.

scholarly journals In Vitro Antimicrobial Activity of the Siderophore Cephalosporin Cefiderocol against Acinetobacter baumannii Strains Recovered from Clinical Samples

Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1309
Author(s):  
Davide Carcione ◽  
Claudia Siracusa ◽  
Adela Sulejmani ◽  
Roberta Migliavacca ◽  
Alessandra Mercato ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Acinetobacter Baumannii ◽  
Inhibition Zone ◽  
Broth Microdilution ◽  
Large Variability ◽  
Gold Standard Method ◽  
Disk Diffusion Test ◽  
In Vitro Antimicrobial Activity ◽  
Broth Microdilution Method

Background: Cefiderocol is a siderophore cephalosporin that exhibits antimicrobial activity against most multi-drug resistant Gram-negative bacteria, including Enterobacterales, Pseudomonas aeruginosa, Acinetobacter baumannii, and Stenotrophomonas maltophilia. Methods: A total of 20 multidrug-resistant A. baumannii strains were isolated from 2020 to 2021, molecularly characterized and tested to assess the in vitro antibacterial activity of cefiderocol. Thirteen strains were carbapenem-hydrolysing oxacillinase OXA-23-like producers, while seven were non-OXA-23-like producers. Minimum inhibitory concentrations (MICs) were determined by broth microdilution, considered as the gold standard method. Disk diffusion test was also carried out using iron-depleted CAMHB plates for cefiderocol. Results: Cefiderocol MICs ranged from 0.5 to 1 mg/L for OXA-23-like non-producing A. baumannii strains and from 0.25 to >32 mg/L for OXA-23-like producers, using the broth microdilution method. Cefiderocol MIC90 was 8 mg/L. Diameter of inhibition zone of cefiderocol ranged from 18 to 25 mm for OXA-23-like non-producers and from 15 to 36 mm for OXA-23-like producers, using the diffusion disk method. A large variability and a low reproducibility were observed during the determination of diameter inhibition zone. Molecular characterization showed that all isolates presented the ISAba1 genetic element upstream the blaOXA-51. Among OXA-23-like non-producers, four were blaOXA-58 positive and two were negative for all the resistance determinants analyzed. Conclusions: Cefiderocol showed in vitro antimicrobial activity against both carbapenem-susceptible and non-susceptible A. baumannii strains, although some OXA-23-like producers were resistant. Further clinical studies are needed to consolidate the role of cefiderocol as an antibiotic against MDR A. baumannii.

scholarly journals Occurrence of Enterocin Genes in Enterococci from Slovak Milk Product Žinčica

2019 ◽  
Vol 50 (3) ◽  
pp. 197-202 ◽  
Author(s):  
A. Lauková ◽  
V. Strompfová ◽  
M. Tomáška ◽  
M. Kološta
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Dairy Product ◽  
Inhibition Zone ◽  
The Other ◽  
Milk Product ◽  
Inhibition Activity ◽  
Gene Detection ◽  
P Gene

Abstract Žinčica is a popular Slovak dairy product made from ewes’ milk. It is a by-product resulting during ewes’ lump cheese processing. Microbiota in Žinčica have rarely been studied, especially enterococci; however, they can produce beneficial substances – bacteriocins. In this study, the presence of Enterocins (Ents) genes were analysed in enterococci from Žinčica and partially also the inhibition activity. Samples of Žinčica were collected from different agrofarms producing ewes’ lump cheese (34) in Central Slovakia. In the enterococci tested, Ent P gene was the most frequently detected (in 6 out of 7 enterococci), followed by Ent A and Ent L50B genes. Ent B gene was detected only in E. faecium 30E1. On the other hand, E. faecalis 31E2 did not contain Ent genes, although it showed inhibition activity against the indicator strains Enterococcus avium EA5, Staphylococcus aureus SA5, Listeria monocytogenes CCM4699 (inhibition zone sizing up to 20 mm). E. faecium 30E1 contained genes of four Ents; however, it showed no inhibition activity. Growth of the four indicators was inhibited due to the antimicrobial activity of E. faecium 32E1 with Ent P gene detection. This is the first study reporting on the occurrence of Ent genes in enterococci from Žinčica.

scholarly journals In Vitro Antimicrobial Activity of Zodia (Evodia suaveolens) Leaf Extract on Pathogenic Agents Dragon Fruit Plant

Jurnal Biota ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 78-85
Author(s):  
Trio Ageng Prayitno ◽  
Nuril Hidayati
Keyword(s):  
Antimicrobial Activity ◽  
Leaf Extract ◽  
Plant Pathogens ◽  
Inhibition Zone ◽  
Diffusion Method ◽  
Leaf Extracts ◽  
Dragon Fruit ◽  
Fruit Plants ◽  
Pathogenic Agents

The use of antimicrobials from plant extracts has not been used optimally to control pathogenic agents in dragon fruit plants. The purpose of this research was to determine the antimicrobial activity of zodia (Evodia suaveolens) leaf extracts on pathogenic agents of dragon fruit plants in vitro. The research method is laboratory research with Completely Randomized Design (CRD). The antimicrobial concentrations of zodia (E. suaveolens) leaf extract used six types including 50%, 60%, 70%, 80%, 90%, and 100% with four replications. The research sample was the leaf of zodia (E. suaveolens), Pseudomonas aeruginosa and Fusarium oxysporum strain Malang. Test the antimicrobial activity of zodia (E. suaveolens) leaf extracts on the growth of P. aeruginosa and F. oxysporum using the disc-diffusion method and wells method. The research instrument was used the observation sheet of the diameter of inhibition zone indicated by the clear zone. The diameter of inhibition zone data were analyzed using the One Way ANOVA test. The results showed that the antimicrobial activity of zodia (E. suaveolens) leaf extract significantly inhibited the growth of P. aeruginosa and F. oxysporum (P <0.05). These results recommend zodia (E. suaveolens) leaf extract as an antimicrobial agent for dragon fruit plant pathogens.

scholarly journals Uses of milk in sweetmeat shops and consumer preferences to milk products at Mymensingh municipality in Bangladesh

2016 ◽  
Vol 2 (2) ◽  
pp. 266-273
Author(s):  
ABM Kawsar Ahmed ◽  
Md Rezwanul Habib ◽  
Samia Afrin ◽  
Mohammad Ashiqul Islam ◽  
Md Harun Ur Rashid
Keyword(s):  
Data Analysis ◽  
Shelf Life ◽  
Distribution Pattern ◽  
Statistical Methods ◽  
Consumer Preferences ◽  
Raw Milk ◽  
Milk Products ◽  
Whole Milk ◽  
Significant Difference ◽  
Research Findings

The work has been designed to investigate the utilization of milk for consumption of fluid milk and milk products, their distribution pattern, pricing, shelf life and consumer’s preference of Mymensingh municipality in Bangladesh. The study was based on milk and milk products and data were collected from the selected sweetmeat shops by direct interview, of which 20 samples were collected from sweetmeat shops and 7 from goalas. Both tabular and statistical methods were used for collected data analysis. Shopkeepers of different sweetmeat shops received raw milk from farmers (52.6%) and goalas (47.4%) and the highest amount of whole milk was required in per unit production of rasomalai (21%) and ghee (18%) whereas the lowest amount in chomchom (9%). Milk products prices were not remained same throughout the year in this municipality due to fluctuation of raw milk availability and their price. Eid, Puja festivals and other educational activities results that may increase milk products selling especially rasogolla and kalojam. Research findings also showed non-significant difference in case of pricing, distribution pattern, shelf life and selling of milk and milk products following sweetmeats.Asian J. Med. Biol. Res. June 2016, 2(2): 266-273

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