scholarly journals TOTAL Escherichia coli PADA SOSIS IKAN YANG DI-COATING DENGAN MIOFIBRIL ASAP CAIR SELAMA PENYIMPANAN

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Jupni Keno ◽  
Henny Adeleida Dien ◽  
Agnes Triasih Agustin
Keyword(s):  
Escherichia Coli ◽  
Nutritional Value ◽  
Room Temperature ◽  
Total Coliform ◽  
Fish Protein ◽  
Gram Negative ◽  
E Coli ◽  
Liquid Smoke ◽  
Refrigerator Temperature ◽  
Descriptive Method

Fish sausages are prepared foods that have a high nutritional value, but that is the weakness of this commodity is rapidly decaying nature. Bacterial pathogens that must be avoided include Escherichia coli. These bacteria are gram-negative, rod-shaped and motile spores are not. The purpose of this study is to calculate the total coliforms and E. coli in fish sausage coating of fish protein myofibrils Black Marlin (Makaira indica) during storage at room temperature (28–29°C), and refrigerator temperature (10–13°C). The method used is descriptive method, which is a study conducted to analyze an individual, the state, or the symptoms of a particular group. The results showed that the total coliform in fish sausage in coating with liquid smoke is stored at room temperature, the lowest value is 7 MPN/g, the highest of 120 MPN/g, while the lowest value refrigerator temperature is 7 MPN/g, the highest 93 MPN/g. Total coliform in fish sausage in smokeless liquid coating stored at room temperature with the lowest value is 7 MPN/g, the highest 210 MPN/g, while the lowest value refrigerator temperature is 7 MPN/g, and the highest is 120 MPN/g. Total coliform in fish sausages are not in the coating deposited at room temperature with the lowest value is 7 MPN/g, the highest of 240 MPN/g, at refrigerator temperature the lowest value is 7 MPN/g, and the highest is 150 MPN/g. Total E. coli showed that the fish sausage in coating with liquid smoke is stored at room temperature, the lowest value is 1 MPN/g, and the highest is 4 MPN/g, while the lowest value refrigerator temperature is <3 MPN/g, and The highest is 3 MPN/g. Total E. coli in fish sausage in smokeless coating liquid stored at room temperature, the lowest value is 2 MPN/g, and the highest is 4 MPN/g, while the temperature of the refrigerator lowest value is 1 MPN/g, and a high of 3 MPN/g. Total E. coli in sausages are not in the coating deposited at room temperature, the lowest value is 2 MPN/g, and the highest is 5 MPN/g, and the refrigerator temperature is the lowest rating 2 MPN/g, the highest is 4 MPN/g during storage .Keywords: fish sausage, coating, myofibril, Eschericia coli.  Sosis ikan merupakan makanan siap saji yang mempunyai nilai gizi tinggi, namun yang menjadi kelemahan dari komoniti ini adalah sifatnya yang cepat membusuk. Bakteri patogen yang harus dihindari antara lain Escherichia coli.  Bakteri ini bersifat gram negatif, berbentuk batang tidak spora dan bersifat motil. Tujuan penelitian ini yaitu untuk menghitung total koliform dan E. coli pada sosis ikan yang dicoating dari miofibril protein ikan Black Marlin (Makaira indica) selama penyimpanan suhu ruang (28–29°C), dan suhu kulkas (10–13°C). Metode penelitian yang digunakan adalah metode deskriptif, yaitu suatu penelitian yang dilakukan untuk menganalisa suatu individu, keadaan, gejala atau kelompok tertentu. Hasil penelitian menunjukkan bahwa total koliform pada sosis ikan yang dicoating dengan asap cair disimpan pada suhu ruang, nilai terendah yaitu 7 MPN/g, tertinggi 120 MPN/g, sedangkan pada suhu kulkas nilai yang terendah yaitu 7 MPN/g, tertinggi 93 MPN/g. Total koliform pada sosis ikan yang dicoating tanpa asap cair disimpan pada suhu ruang dengan nilai terendah yaitu 7 MPN/g, tertinggi 210 MPN/g, sedangkan pada suhu kulkas nilai yang terendah yaitu 7 MPN/g, dan tertinggi 120 MPN/g. Total koliform pada sosis ikan tidak dicoating disimpan pada suhu ruang dengan nilai terendah yaitu 7 MPN/g, tertinggi 240 MPN/g , pada suhu kulkas nilai terendah yaitu 7 MPN/g , dan tertinggi 150 MPN/g. Total E. coli menunjukkan bahwa pada sosis ikan yang dicoating dengan asap cair disimpan pada suhu ruang, yaitu nilai terendah 3 MPN/g, dan tertinggi 4 MPN/g, sedangkan pada suhu kulkas nilai terendah yaitu <3 MPN/g, dan tertinggi 3 MPN/g. Total E. coli pada sosis ikan yang dicoating tanpa asap cair disimpan pada suhu ruang, yaitu nilai terendah 3 MPN/g, dan tertinggi 4 MPN/g, sedangkan pada suhu kulkas nilai terendah yaitu <3 MPN/g , dan tertinggi 3 MPN/g. Total E. coli pada sosis tidak dicoatingdisimpan pada suhu ruang, yaitu nilai terendah 4 MPN/g, dan tertinggi 7 MPN/g, dan pada suhu kulkas yaitu nilai terendah 3 MPN/g, tertinggi 4 MPN/g selama penyimpanan.Kata kunci: sosis ikan, coating, myofibril, Eschericia coli.

scholarly journals MUTU MIKROBIOLOGIS BAKSO IKAN YANG DIRENDAM ASAP CAIR, DIKEMAS VAKUM, DIPASTEURISASI DAN DISIMPAN PADA SUHU DINGIN

2015 ◽  
Vol 3 (2) ◽  
Author(s):  
Oktavianus Alexander Poluakan ◽  
Henny Adeleida Dien ◽  
Frans Gruber Ijong
Keyword(s):  
Escherichia Coli ◽  
Microbiological Quality ◽  
Total Coliform ◽  
Plate Count ◽  
High Water Content ◽  
Cold Temperatures ◽  
E Coli ◽  
Liquid Smoke ◽  
Total Plate Count ◽  
Spoilage Bacteria

Fish meatball is a processed fish product and quite popular for the public. The weakness of fish meatball is quickly decayed which is caused by the growth of spoilage bacteria and pathogens during the storage. Liquid smoke has a function as a barrier to the development of bacteria. Pasteurization, vacuum packaging and storage of cold temperatures could inhibit the growth of bacterium. The purpose of these study is to assessment the Total Plate Count, Total Coliform and Escherichia coli, and Total Salmonella for the microbiological quality of fish meatball soaked in liquid-smoked, vacuum packed, pasteurized and stored at cold temperatures. Fish meatball soaked in liquid smoke 0.8% for 30 minutes and pasteurized at temperature of ±88ºC for 30, 60 and 90 minutes, then vacuum packed and stored at cold temperatures. Based on the results of observations, Total Plate Count from fish meatball can last up for 10 days with the highest TPC value of 6.3 x 104 CFU / g according to ISO 7266: 2014. Total Salmonella until a 20th day had a negative value. Also, Total Coliform and E. coli growth does not found in the cold storage for 30 days. Value fish balls high water content and pH are good for bacterial growth. Immersion in liquid-smoked indicates that liquid-smoked is a good antibacterial preservative for use as an additive. Keyword: Fish Meatball, Liquid-Smoked, Pasteurization, Bacteria.   Bakso ikan merupakan produk olahan ikan yang cukup digemari masyarakat. Kelemahan dari bakso ikan yaitu cepat mengalami pembusukan yang diakibatkan oleh pertumbuhan bakteri pembusuk dan patogen selama masa simpan. Asap cair memiliki fungsi sebagai penghambat perkembangan bakteri. Pasteurisasi, Pengemasan secara vakum dan penyimpanan suhu dingin dilakukan untuk menghambat pertumbuhan bakteri. Penelitian ini bertujuan untuk menghitung Angka Lempeng Total, Total Salmonella dan Total Koliform dan Escherichia coli terhadap mutu mikrobiologis bakso ikan yang direndam asap cair, dikemas vakum, dipasteurisasi dan disimpan pada suhu dingin. Bakso direndam pada asap cair 0.8% selama 30 menit dan dipasteurisasi pada suhu ±88ºC selama 30, 60 dan 90 menit, lalu dikemas vakum dan disimpan pada suhu dingin. Berdasarkan nilai hasil pengamatan Angka lempeng Total, bakso ikan dapat bertahan selama 10 hari dengan nilai ALT tertinggi 6.3 x 104 CFU/g dan masih dapat diterima SNI 7266:2014. Total Salmonella sp sampai pada hari ke 20 memiliki nilai negative dan Total Koliform dan E. coli tidak terdeteksi pertumbuhan sampai pada penyimpanan dingin selama 30 hari. Nilai kadar air bakso ikan tinggi dan pH yang baik untuk pertumbuhan bakteri. Perendaman dalam asap cair menunjukkan bahwa asap cair merupakan pengawet antibakteri yang baik untuk digunakan sebagai bahan tambahan. Kata Kunci: Bakso Ikan, Asap Cair, Pasteurisasi, Bakteri.

Synthesis of Chalcones and Nucleosides Incorporating [1, 3, 4]Oxadiazolenone Core and Evaluation of their Antifungal and Antibacterial Activities

2020 ◽  
Vol 15 (6) ◽  
pp. 665-679
Author(s):  
Alok K. Srivastava ◽  
Lokesh K. Pandey
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Bacillus Subtilis ◽  
Antifungal Activity ◽  
Aspergillus Niger ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Good Antibacterial Activity

Background: [1, 3, 4]oxadiazolenone core containing chalcones and nucleosides were synthesized by Claisen-Schmidt condensation of a variety of benzaldehyde derivatives, obtained from oxidation of substituted 5-(3/6 substituted-4-Methylphenyl)-1, 3, 4-oxadiazole-2(3H)-one and various substituted acetophenone. The resultant chalcones were coupled with penta-O-acetylglucopyranose followed by deacetylation to get [1, 3, 4] oxadiazolenone core containing chalcones and nucleosides. Various analytical techniques viz IR, NMR, LC-MS and elemental analysis were used to confirm the structure of the synthesised compounds.The compounds were targeted against Bacillus subtilis, Staphylococcus aureus and Escherichia coli for antibacterial activity and Aspergillus flavus, Aspergillus niger and Fusarium oxysporum for antifungal activity. Methods: A mixture of Acid hydrazides (3.0 mmol) and N, Nʹ- carbonyl diimidazole (3.3 mmol) in 15 mL of dioxane was refluxed to afford substituted [1, 3, 4]-oxadiazole-2(3H)-one. The resulted [1, 3, 4]- oxadiazole-2(3H)-one (1.42 mmol) was oxidized with Chromyl chloride (1.5 mL) in 20 mL of carbon tetra chloride and condensed with acetophenones (1.42 mmol) to get chalcones 4. The equimolar ratio of obtained chalcones 4 and β -D-1,2,3,4,6- penta-O-acetylglucopyranose in presence of iodine was refluxed to get nucleosides 5. The [1, 3, 4] oxadiazolenone core containing chalcones 4 and nucleosides 5 were tested to determined minimum inhibitory concentration (MIC) value with the experimental procedure of Benson using disc-diffusion method. All compounds were tested at concentration of 5 mg/mL, 2.5 mg/mL, 1.25 mg/mL, 0.62 mg/mL, 0.31 mg/mL and 0.15 mg/mL for antifungal activity against three strains of pathogenic fungi Aspergillus flavus (A. flavus), Aspergillus niger (A. niger) and Fusarium oxysporum (F. oxysporum) and for antibacterial activity against Gram-negative bacterium: Escherichia coli (E. coli), and two Gram-positive bacteria: Staphylococcus aureus (S. aureus) and Bacillus subtilis(B. subtilis). Result: The chalcones 4 and nucleosides 5 were screened for antibacterial activity against E. coli, S. aureus and B. subtilis whereas antifungal activity against A. flavus, A. niger and F. oxysporum. Compounds 4a-t showed good antibacterial activity whereas compounds 5a-t containing glucose moiety showed better activity against fungi. The glucose moiety of compounds 5 helps to enter into the cell wall of fungi and control the cell growth. Conclusion: Chalcones 4 and nucleosides 5 incorporating [1, 3, 4] oxadiazolenone core were synthesized and characterized by various spectral techniques and elemental analysis. These compounds were evaluated for their antifungal activity against three fungi; viz. A. flavus, A. niger and F. oxysporum. In addition to this, synthesized compounds were evaluated for their antibacterial activity against gram negative bacteria E. Coli and gram positive bacteria S. aureus, B. subtilis. Compounds 4a-t showed good antibacterial activity whereas 5a-t showed better activity against fungi.

scholarly journals Proteomic response of Escherichia coli to a membrane lytic and iron chelating truncated Amaranthus tricolor defensin

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Tessa B. Moyer ◽  
Ashleigh L. Purvis ◽  
Andrew J. Wommack ◽  
Leslie M. Hicks
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Antimicrobial Peptides ◽  
Mechanism Of Action ◽  
Gram Negative Bacteria ◽  
Amaranthus Tricolor ◽  
Core Motif ◽  
Gram Negative ◽  
E Coli ◽  
Membrane Lysis

Abstract Background Plant defensins are a broadly distributed family of antimicrobial peptides which have been primarily studied for agriculturally relevant antifungal activity. Recent studies have probed defensins against Gram-negative bacteria revealing evidence for multiple mechanisms of action including membrane lysis and ribosomal inhibition. Herein, a truncated synthetic analog containing the γ-core motif of Amaranthus tricolor DEF2 (Atr-DEF2) reveals Gram-negative antibacterial activity and its mechanism of action is probed via proteomics, outer membrane permeability studies, and iron reduction/chelation assays. Results Atr-DEF2(G39-C54) demonstrated activity against two Gram-negative human bacterial pathogens, Escherichia coli and Klebsiella pneumoniae. Quantitative proteomics revealed changes in the E. coli proteome in response to treatment of sub-lethal concentrations of the truncated defensin, including bacterial outer membrane (OM) and iron acquisition/processing related proteins. Modification of OM charge is a common response of Gram-negative bacteria to membrane lytic antimicrobial peptides (AMPs) to reduce electrostatic interactions, and this mechanism of action was confirmed for Atr-DEF2(G39-C54) via an N-phenylnaphthalen-1-amine uptake assay. Additionally, in vitro assays confirmed the capacity of Atr-DEF2(G39-C54) to reduce Fe3+ and chelate Fe2+ at cell culture relevant concentrations, thus limiting the availability of essential enzymatic cofactors. Conclusions This study highlights the utility of plant defensin γ-core motif synthetic analogs for characterization of novel defensin activity. Proteomic changes in E. coli after treatment with Atr-DEF2(G39-C54) supported the hypothesis that membrane lysis is an important component of γ-core motif mediated antibacterial activity but also emphasized that other properties, such as metal sequestration, may contribute to a multifaceted mechanism of action.

scholarly journals A High-Throughput Approach To Identify Compounds That Impair Envelope Integrity in Escherichia coli

2016 ◽  
Vol 60 (10) ◽  
pp. 5995-6002 ◽  
Author(s):  
Kristin R. Baker ◽  
Bimal Jana ◽  
Henrik Franzyk ◽  
Luca Guardabassi
Keyword(s):  
Escherichia Coli ◽  
High Throughput ◽  
High Throughput Screening ◽  
Gram Negative Bacteria ◽  
Chromogenic Substrate ◽  
Intrinsic Resistance ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Screening Platform

ABSTRACTThe envelope of Gram-negative bacteria constitutes an impenetrable barrier to numerous classes of antimicrobials. This intrinsic resistance, coupled with acquired multidrug resistance, has drastically limited the treatment options against Gram-negative pathogens. The aim of the present study was to develop and validate an assay for identifying compounds that increase envelope permeability, thereby conferring antimicrobial susceptibility by weakening of the cell envelope barrier in Gram-negative bacteria. A high-throughput whole-cell screening platform was developed to measureEscherichia colienvelope permeability to a β-galactosidase chromogenic substrate. The signal produced by cytoplasmic β-galactosidase-dependent cleavage of the chromogenic substrate was used to determine the degree of envelope permeabilization. The assay was optimized by using known envelope-permeabilizing compounds andE. coligene deletion mutants with impaired envelope integrity. As a proof of concept, a compound library comprising 36 peptides and 45 peptidomimetics was screened, leading to identification of two peptides that substantially increased envelope permeability. Compound 79 reduced significantly (from 8- to 125-fold) the MICs of erythromycin, fusidic acid, novobiocin and rifampin and displayed synergy (fractional inhibitory concentration index, <0.2) with these antibiotics by checkerboard assays in two genetically distinctE. colistrains, including the high-risk multidrug-resistant, CTX-M-15-producing sequence type 131 clone. Notably, in the presence of 0.25 μM of this peptide, both strains were susceptible to rifampin according to the resistance breakpoints (R> 0.5 μg/ml) for Gram-positive bacterial pathogens. The high-throughput screening platform developed in this study can be applied to accelerate the discovery of antimicrobial helper drug candidates and targets that enhance the delivery of existing antibiotics by impairing envelope integrity in Gram-negative bacteria.

Screening of Commercial and Pecan Shell–Extracted Liquid Smoke Agents as Natural Antimicrobials against Foodborne Pathogens

2012 ◽  
Vol 75 (6) ◽  
pp. 1148-1152 ◽  
Author(s):  
ELLEN J. VAN LOO ◽  
D. BABU ◽  
PHILIP G. CRANDALL ◽  
STEVEN C. RICKE
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
Salmonella Enteritidis ◽  
Antioxidant Properties ◽  
Inhibitory Effects ◽  
Natural Antimicrobials ◽  
E Coli ◽  
Liquid Smoke ◽  
Water Based ◽  
Smoke Sample

Liquid smoke extracts have traditionally been used as flavoring agents, are known to possess antioxidant properties, and serve as natural alternatives to conventional antimicrobials. The antimicrobial efficacies of commercial liquid smoke samples may vary depending on their source and composition and the methods used to extract and concentrate the smoke. We investigated the MICs of eight commercial liquid smoke samples against Salmonella Enteritidis, Staphylococcus aureus, and Escherichia coli. The commercial liquid smoke samples purchased were supplied by the manufacturer as water-based or concentrated extracts of smoke from different wood sources. The MICs of the commercial smokes to inhibit the growth of foodborne pathogens ranged from 0.5 to 6.0% for E. coli, 0.5 to 8.0% for Salmonella, and 0.38 to 6% for S. aureus. The MIC for each liquid smoke sample was similar in its effect on both E. coli and Salmonella. Solvent-extracted antimicrobials prepared using pecan shells displayed significant differences between their inhibitory concentrations depending on the type of solvent used for extraction. The results indicated that the liquid smoke samples tested in this study could serve as effective natural antimicrobials and that their inhibitory effects depended more on the solvents used for extraction than the wood source.

scholarly journals Multiplex Polymerase Chain Reaction Assay for Identification of Enterotoxigenic Escherichia Coli Strains

2001 ◽  
Vol 13 (4) ◽  
pp. 308-311 ◽  
Author(s):  
Jacek Osek
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Multiplex Polymerase Chain Reaction ◽  
Direct Determination ◽  
Enteric Bacteria ◽  
Enterotoxigenic Escherichia Coli ◽  
Chain Reaction ◽  
Gram Negative ◽  
E Coli ◽  
Polymerase Chain

A multiplex polymerase chain reaction (PCR) system was developed for identification of enterotoxigenic Escherichia coli (ETEC) strains and to differentiate them from other gram negative enteric bacteria. This test simultaneously amplifies heat-labile (LTI) and heat-stable (STI and STII) toxin sequences and the E. coli-specific universal stress protein ( uspA). The specificity of the method was validated by single PCR tests performed with the reference E. coli and non- E. coli strains and with bacteria isolated from pig feces. The multiplex PCR allowed the rapid and specific identification of enterotoxin-positive E. coli and may be used as a method for direct determination of ETEC and to differentiate them from other E. coli and gram-negative enteric isolates.

Validation of Time and Temperature Values as Critical Limits for the Control of Escherichia coli O157:H7 during the Production of Fresh Ground Beef

2006 ◽  
Vol 69 (8) ◽  
pp. 1978-1982 ◽  
Author(s):  
J. E. MANN ◽  
M. M. BRASHEARS
Keyword(s):  
Escherichia Coli ◽  
Room Temperature ◽  
Hazard Analysis ◽  
Control Point ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
Meat Processing ◽  
E Coli ◽  
Critical Control Point ◽  
Critical Limits

In order to provide beef processors with valuable data to validate critical limits set for temperature during grinding, a study was conducted to determine Escherichia coli O157:H7 growth at various temperatures in raw ground beef. Fresh ground beef samples were inoculated with a cocktail mixture of streptomycin-resistant E. coli O157:H7 to facilitate recovery in the presence of background flora. Samples were held at 4.4, 7.2, and 10°C, and at room temperature (22.2 to 23.3°C) to mimic typical processing and holding temperatures observed in meat processing environments. E. coli O157:H7 counts were determined by direct plating onto tryptic soy agar with streptomycin (1,000 μg/ml), at 2-h intervals over 12 h for samples held at room temperature. Samples held under refrigeration temperatures were sampled at 4, 8, 12, 24, 48, and 72 h. Less than one log of E. coli O157:H7 growth was observed at 48 h for samples held at 10°C. Samples held at 4.4 and 7.2°C showed less than one log of E. coli O157:H7 growth at 72 h. Samples held at room temperature showed no significant increase in E. coli O157:H7 counts for the first 6 h, but increased significantly afterwards. These results illustrate that meat processors can utilize a variety of time and temperature combinations as critical limits in their hazard analysis critical control point plans to minimize E. coli O157:H7 growth during the production and storage of ground beef.

scholarly journals Studies on the Preservation of Raw Cow’s Milk by Chemical Method

1970 ◽  
Vol 42 (3) ◽  
pp. 317-326 ◽  
Author(s):  
F Rokhsana ◽  
UK Das ◽  
R Yeasmin ◽  
A Nahar ◽  
S Parveen
Keyword(s):  
Hydrogen Peroxide ◽  
Chemical Method ◽  
Room Temperature ◽  
Storage Period ◽  
Total Coliform ◽  
Human Consumption ◽  
Milk Products ◽  
E Coli ◽  
Keeping Quality ◽  
Control Milk

Studies carried out to develop a technique for the preservation of cow's milk in raw condition using hydrogen peroxide (H2O2) as a preservative. Fresh cow’s milk was collected and experiments were conducted by four treatments in order to achieve the optimum condition of storage. The treatments were with various concentration of H2O2 starting from 0.05 %, 0.1 %, 0.2 %, 0.3 %, 0.4 %, & 0.5 %. Treated milk with 0.05 % concentration of H2O2 had storage period of 20 days compared to that of the control one (5 days only) in refrigerated temperature (±8°C). On the other hand hydrogen peroxide treated milk (0.05 %) had a storage period of 8 hours at room temperature (±28°C). Results also showed that the higher concentration of H2O2 had no effect on storage period than that of control. Milk products like kheer and halawa prepared by treated milk and stored for 20 days showed almost nil growth of total coliform and E. coli which means that food products prepared from hydrogen peroxide treated milk is safe for human consumption. Key words: Raw, Storage, Hydrogen peroxide, Preservative, keeping quality, Pasteurization, deteriorated, MPN. Bangladesh J. Sci. Ind. Res. 42(3), 317-326, 2007

scholarly journals GREEN SYNTHESIS OF MAGNETIC IRON NANOPARTICLES USING MEDICINAL PLANT TRIDAX PROCUMBENS LEAF EXTRACTS AND ITS APPLICATION AS AN ANTIMICROBIAL AGENT AGAINST E. COLI

2020 ◽  
pp. 34-39
Author(s):  
YOJANA Y. PATIL ◽  
VAISHNVI B. SUTAR ◽  
ARPITA P. TIWARI
Keyword(s):  
Escherichia Coli ◽  
Magnetic Nanoparticles ◽  
Iron Nanoparticles ◽  
Most Probable Number ◽  
Leaf Extracts ◽  
Probable Number ◽  
Gram Negative ◽  
E Coli ◽  
Tridax Procumbens ◽  
Escherichia Coli Bacteria

Objective: The present study was aimed at the biological synthesis of magnetic iron nanoparticles by using the plant extract of Tridax procumbens and also to study their antimicrobial property against gram-negative bacteria (Escherichia coli). Methods: The synthesis of magnetic iron nanoparticles was carried out by the co-precipitation method using biological methods like plant extract as reducing agent and capping agents are biocompatible and non-hazardous. These nanoparticles were characterized by UV-Visible spectroscopy, XRD (X-Ray Diffraction), and SEM (Scanning Electron Microscope). As well as antibacterial activity of the nanoparticles was carried out by agar well diffusion method and Most Probable Number (MPN) method against gram-negative E. coli (Escherichia coli) bacteria. Results: The average crystallite size of Magnetic Nanoparticles (MNPs) was found to be 72 nm by X-ray diffraction. The optical absorption band at wavelengths of 240 nm and 402 nm was obtained from the UV Visible spectrum. Spherical shape morphology was observed in SEM studies. The antibacterial assay clearly expressed that E. coli showed a maximum zone of inhibition (15±0.15 mm) at 2 mg/ml and 1 mg/ml concentration was found for Magnetic Nanoparticles. In the Most Probable Number (MPN) test it is seen that the bacterial count is reduced after adding synthesized NPs into the water sample. Conclusion: The results of the present study conclude that the Magnetic Nanoparticles synthesized using Tridax procumbens leaf extracts is found to be stable and show good antibacterial activity against gram-negative (Escherichia coli) bacteria.

scholarly journals Antibiogram Profiling and Thermal Inactivation of Staphylococcus aureus and Escherichia coli Isolated from Milk of Dharan, Nepal

2020 ◽  
pp. 81-87
Author(s):  
Susmita Phattepuri ◽  
Prince Subba ◽  
Arjun Ghimire ◽  
Shiv Nandan Sah
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Thermal Inactivation ◽  
Total Coliform ◽  
Plate Count ◽  
Diffusion Method ◽  
E Coli ◽  
Coliform Count ◽  
Z Value ◽  
D Values

Milk is an excellent medium for the growth of many bacteria. This study aimed to determine antibiotic profiling and thermal inactivation of Staphylococcus aureus and Escherichia coli isolated from raw milk of Dharan. Total viable count, total Staphylococcal count, and total coliform count were carried out by conventional microbiological methods. Identification was done on the basis of Gram staining and biochemical tests. The antibiotic susceptibility test of the isolates carried out by the modified Kirby-Baur disc diffusion method. Thermal inactivation of S. aureus and E. coli were carried out by subjecting to thermal treatment in a water bath. Total plate count ranged from 204×104 CFU/mL to 332×105 CFU/mL. Total staphylococcal count and total coliform count ranged from 14×105 CFU/mL to 8×106 CFU/mL and 11×104 CFU/mL to 3×106 CFU/mL respectively. S. aureus showed an increasing resistance patterns towards Ampicillin, Cefotixin, Carbenicillin and Cefotaxime. Ciprofloxacin, Erythromycin, Amikacin, Gentamycin, Azithromycin, and Chloramphenicol were found to be effective against S. aureus. All the E. coli isolates were resistant to Ampicillin and least resistant to Cefotixin. Chloramphenicol, Amikacin, Azithromycin, and Nalidixic acid were found highly effective to E. coli. The D-values for S. aureus at 56°C, 58°C and 60°C were 1.36 min, 1.19 min, and 1.09 min respectively. The Z-value was 14.92°C. While D-values were obtained as 0.98 min, 0.75 min, and 0.57 min for E. coli at 56° C, 58° C and 60° C respectively, and Z-value was 9.75° C. Hence, S. aureus was found to be more heat resistant than E. coli.

Sign in / Sign up

Export Citation Format

Share Document