scholarly journals Biological Potential of Semi-Purified Enterocin of Enterococcus Sp. Yt3 Against Selected Food Pathogens

2019 ◽  
Vol 35 (5) ◽  
pp. 1584-1596
Author(s):  
Charu Khanna ◽  
Shalini Singh ◽  
Manish Vyas ◽  
Sujata Das

The efforts for prevention of food borne illness and infections draw great attention, worldwide. Different methods, both physical as well as chemical, are commonly used for improving shelf life of food, but limited efficiency of physical methods, and potential health hazards associated with chemical methods, have brought biological processes in the limelight. One such natural, environment friendly, highly effective natural food preservants are, bacteriocins. Thus, there is a continuous need for better bacteriocin producers in the search for more effective bacteriocins than what are already available in the market. In the current study, food samples were collected from local market of Jalandhar, Punjab, and evaluated for bacteriocin producing Lactic acid bacteria. Enterococcus sp. YT3 was found to be the most efficient bacteriocin producer among the isolates, with higher bacteriocin activity exhibited by the given strain under optimized cultural conditions. The partially purified bacteriocin have molecular weight between 35kDa & 48kDa, possess pH (2-10) and thermal stability (even at 121o C for 20 minutes), and exhibit biological potential against different bacteria (E. coli, P. aeruginosa, L. monocytogenes, S. aureus and B. subtilis). Future studies will focus on checking different food samples for real time evaluation of shelf life improvement.

2000 ◽  
Vol 66 (1) ◽  
pp. 213-218 ◽  
Author(s):  
Kellogg J. Schwab ◽  
Frederick H. Neill ◽  
Rebecca L. Fankhauser ◽  
Nicholas A. Daniels ◽  
Stephan S. Monroe ◽  
...  

ABSTRACT “Norwalk-like viruses” (NLVs) and hepatitis A virus (HAV) are the most common causes of virus-mediated food-borne illness. Epidemiological investigations of outbreaks associated with these viruses have been hindered by the lack of available methods for the detection of NLVs and HAV in foodstuffs. Although reverse transcription (RT)-PCR methods have been useful in detecting NLVs and HAV in bivalve mollusks implicated in outbreaks, to date such methods have not been available for other foods. To address this need, we developed a method to detect NLVs and HAV recovered from food samples. The method involves washing of food samples with a guanidinium-phenol-based reagent, extraction with chloroform, and precipitation in isopropanol. Recovered viral RNA is amplified with HAV- or NLV-specific primers in RT-PCRs, using a viral RNA internal standard control to identify potential sample inhibition. By this method, 10 to 100 PCR units (estimated to be equivalent to 102 to 103 viral genome copies) of HAV and Norwalk virus seeded onto ham, turkey, and roast beef were detected. The method was applied to food samples implicated in an NLV-associated outbreak at a university cafeteria. Sliced deli ham was positive for a genogroup II NLV as determined by using both polymerase- and capsid-specific primers and probes. Sequence analysis of the PCR-amplified capsid region of the genome indicated that the sequence was identical to the sequence from virus detected in the stools of ill students. The developed method is rapid, simple, and efficient.


2015 ◽  
Vol 26 ◽  
pp. 1-9
Author(s):  
R Tuladhar ◽  
Anjana Singh

Analysis of street foods of Kathmandu for bacterial contamination was performed in 12 different street foods. The surveillance study was carried in 200 children of primary grade from public school and 12 street vendors for the health hygiene and hazards associated with street food. Poor hygiene practice in preparation and handling of street food has been observed in the vendors. The lack of the knowledge in vendors about the source of bacterial contamination and absence of surveillance on street food has subjected street food to the high potential for food borne illness. The inadequate safety measure adopted by the targeted consumers of street food, the children, has augmented the risk associated with street food. All the food samples analyzed were contaminated with bacteria. The mesophilic count was recorded highest in Panipuri while as coliform count was highest in Chana tarkari. The least count of both was observed in Aaloo chop . Highest number of Staphylococccus aureus was found in Kerau (1.5X103cfu/g) and lowest in Momo (8.3 cfu/g). The dominant bacteria contaminating the food was S. aureus followed by Bacillus alvei, Escherichia coli, Enterobacter aerogenes, Bacillus subtilis, Serratia sp., S. saprophyticus. The contaminated hand and clothing of the person who prepare food are the major source of S. aureus. Highest percentage of E. coli found in Panipuri must be due to the use of contaminated water. Chana chatpate and Chana tarkari were the foods found to be contaminated with Salmonella sp. The type of food and the degree of hygiene practice adopted by vendor refl ects the type and magnitude of bacterial contamination. Implementation of hygienic practices in vendors may reduce the contamination of street food and health education of the school children will curtail the incidences of food borne illness. Periodical monitoring of quality of street food will avoid any future outbreaks of bacterial pathogen.J. Nat. Hist. Mus. Vol. 26, 2012: 1-9


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Adriana Blanco-Padilla ◽  
Karen M. Soto ◽  
Montserrat Hernández Iturriaga ◽  
Sandra Mendoza

Natural food antimicrobials are bioactive compounds that inhibit the growth of microorganisms involved in food spoilage or food-borne illness. However, stability issues result in degradation and loss of antimicrobial activity. Nanoencapsulation allows protection of antimicrobial food agents from unfavorable environmental conditions and incompatibilities. Encapsulation of food antimicrobials control delivery increasing the concentration of the antimicrobials in specific areas and the improvement of passive cellular absorption mechanisms resulted in higher antimicrobial activity. This paper reviews the present state of the art of the nanostructures used as food antimicrobial carriers including nanoemulsions, nanoliposomes, nanoparticles, and nanofibers.


Author(s):  
Tejinder Pal Singh ◽  
Sarang Dilip Pophaly ◽  
Ruby Siwach

Globally, there is an increasing demand for minimally processed, easily prepared, and ready-to-eat fresh food, globalization of food trade, and distribution from centralized processing which pose major challenges for food safety and quality because perishable food may get contaminated with undesirable microorganisms. Food spoilage adversely affects the economy and also erodes the consumer's confidence. On other hand, food-borne illness leads to loss of earnings and productivity, unemployment and litigation, and weakens trade and tourism. Another challenge for the food producers is to produce less stable foods by processes that confer less harm to the detrimental microflora. A challenge for food producers is to develop products with a sufficiently longer shelf-life and at a competitive price. This brings them to the most promising approach to this end, the so-called biopreservation. This chapter provides a scientific background, functionality, as well as food applications and further commercial aspects of biopreservatives derived from microbial sources.


2018 ◽  
Vol 7 (2) ◽  
pp. 2073 ◽  
Author(s):  
Renu Khare ◽  
Agarwal M.K. ◽  
Sameer S. Bhagayavant ◽  
Poonam Verma ◽  
Nagar D.P.

India is an agrarian country two-thirds of its population is engaged directly or indirectly in agricultural activities. In recent years many food borne pathogens have become major threat to public health and safety.  The consumption of contaminated food grains or products has been considered to be the leading source of human food borne infections. Surveillance studies have provided data and a better understanding into the existence and spread of food borne pathogens. Aflatoxins produced by Aspergillus species are important toxic secondary metabolites known for their impacts on animal and human health, and their effects on the economic loss of key grain and nut crops. Several molecular techniques (including multilocus sequence typing, pulsed field gel electrophoresis, DNA sequencing, multiplex PCR, RAPD, and many more) are available for detection and characterisation of pathogenic microorganisms from food samples, which provide reliable epidemiological data for tracing the source of infections. Present study highlights the possible use of PCR technique, in surveillance and detection of A. flavus in fungal infested food grains. The current study was carried out to elucidate the infestation of aflatoxin producing fungus on both kharif (groundnut, rice and maize) and Rabi crops (wheat, gram and soybean). Total 15 samples were collected randomly from local market of Gwalior (M.P). Out of fifteen only nine (60%) samples were found to be Aspergillus positive. Seven samples were infested by Aspergillus flavus and two by A. niger. The selected fungal isolates were identified by amplifying aflR gene of A. flavus in Thermo Cycler.


2003 ◽  
Vol 69 (3) ◽  
pp. 1642-1646 ◽  
Author(s):  
Yuan-Tong Lin ◽  
Ronald Labbe

ABSTRACT Clostridium perfringens is a leading cause of bacterial food-borne illness in countries where consumption of meat and poultry is high. For example, each year in the United States, this organism is the second or third most common cause of confirmed cases of food-borne illness. Surveys of the incidence of this organism in retail foods were done in the 1960s without regard to whether isolates were enterotoxigenic. It is now known that not all strains of this organism possess the enterotoxin gene responsible for illness. We examined the incidence of this organism in 131 food samples from retail food stores in an area of the northeastern United States. Forty isolates were obtained by using the iron milk method at 45°C, with confirmation by use of motility nitrate and lactose gelatin media. The presence of the C. perfringens enterotoxin (cpe) and alpha toxin (cpa) genes was determined by PCR using previously published primer sequences. All isolates possessed cpa. None of the isolates were identified as carrying the cpe gene by this method or by another method using a digoxigenin-labeled gene probe. Consistent with these results, none of the sporulating-cell extracts contained enterotoxin as determined by reverse passive latex hemagglutination. Pulsed-field gel electrophoresis was used to determine the genetic relatedness of the isolates. About 5% of the isolates were considered to be closely related (2- to 3-band difference). The others were considered to be unrelated to one another. The results demonstrate the rarity of cpe+ strains in retail foods and the genetic diversity among nonoutbreak strains.


2019 ◽  
Vol 36 (1) ◽  
pp. 45-47
Author(s):  
Nafisa Tanjia ◽  
Nahida Akhter ◽  
Ajoy Roy ◽  
Mir Shefaly Akhter ◽  
Muniruddin Ahmed ◽  
...  

Street food contamination is common and has a potential health hazards throughout the world. These categories of foods are very popular among the students of Academic Institutions (Universities) of Dhaka city, Bangladesh for their appealing look and reasonable cost. This study was conducted to determine the presence of E. coli, Shigella sp. and Vibrio sp. in the street foods. Two hundred and forty-two food samples were collected from 20 University premises of Dhaka city. Biochemical tests were performed on suspected colonies for the identification of the relevant bacteria obtained from the samples. E. coli, Vibrio sp., and Shigella sp. were identified in 18% samples, where E. coli was found in 12%, Vibrio sp. was identified in 5%, and Shigella sp. in <1.0% food sample studied. The samples from which E. coli and food borne pathogens were obtained were considered unsatisfactory for human consumption.Presence of enteric bacteria in street foods indicates that the students of different Universities in Dhaka city might be at high risk of food borne disease Bangladesh J Microbiol, Volume 36 Number 1 June 2019, pp 45-47


2001 ◽  
Vol 67 (1) ◽  
pp. 217-224 ◽  
Author(s):  
Stacy J. Favrin ◽  
Sabah A. Jassim ◽  
Mansel W. Griffiths

ABSTRACT Salmonella is the second-leading cause of food-borne illness in most developed countries, causing diarrhea, cramps, vomiting, and often fever. Many rapid methods are available for detection of Salmonella in foods, but these methods are often insensitive or expensive or require a high degree of technical ability to perform. In this paper we describe development and characterization of a novel assay that utilizes the normal infection cycle of bacteriophage SJ2 for detection of Salmonella enterica serovar Enteritidis in broth. The assay consists of four main stages: (i) capture and concentration of target cells by using immunomagnetic separation (IMS); (ii) infection of the target bacterium with phage; (iii) amplification and recovery of progeny phage; and (iv) assay of progeny phage on the basis of their effect on a healthy population of host cells (signal-amplifying cells). The end point of the assay can be determined by using either fluorescence or optical density measurements. The detection limit of the assay in broth is less than 104 CFU/ml, and the assay can be performed in 4 to 5 h. The results of this study demonstrate that the IMS-bacteriophage assay is a rapid, simple, and sensitive technique for detection of Salmonella serovar Enteritidis in broth cultures which can be applied to preenriched food samples.


Author(s):  
Tejinder Pal Singh ◽  
Sarang Dilip Pophaly ◽  
Ruby Siwach

Globally, there is an increasing demand for minimally processed, easily prepared, and ready-to-eat fresh food, globalization of food trade, and distribution from centralized processing which pose major challenges for food safety and quality because perishable food may get contaminated with undesirable microorganisms. Food spoilage adversely affects the economy and also erodes the consumer's confidence. On other hand, food-borne illness leads to loss of earnings and productivity, unemployment and litigation, and weakens trade and tourism. Another challenge for the food producers is to produce less stable foods by processes that confer less harm to the detrimental microflora. A challenge for food producers is to develop products with a sufficiently longer shelf-life and at a competitive price. This brings them to the most promising approach to this end, the so-called biopreservation. This chapter provides a scientific background, functionality, as well as food applications and further commercial aspects of biopreservatives derived from microbial sources.


2010 ◽  
Vol 56 (11) ◽  
pp. 943-951 ◽  
Author(s):  
Kaedra Wetzel ◽  
Jiyoung Lee ◽  
Chang Soo Lee ◽  
Margaret Binkley

The consumption and use of edible flowers as food is growing; however, no study has been conducted to evaluate their role in the cause of food-borne illness or in food safety. Recent food-borne outbreaks traced to fresh herbs have raised concern about their processing and handling. Basil, one of the most commonly used fresh herbs, has been identified as a source of food-borne illness. Baseline assessments of microflora were performed, and the microbial diversity between growing methods (organic vs. conventional) was compared. DNA sequencing was used to identify the microbial flora present on fresh edible flower and basil samples. The most predominant species identified were Enterobacter hormaechei (10%), Acinetobacter calcoaceticus (10%), Enterobacter ludwigii (10%), Enterobacter asburiae (6%), and Enterobacter cowanii (6%). Pseudomonas aeruginosa (6%), Salmonella enterica (6%), and Bacillus amyloliquefaciens (2%) were also isolated. Phylogenetic analysis showed that most species of isolated bacteria belonged to the phyla Gammaproteobacteria (81.2%) and Firmicutes (18.8%). Statistical analysis, diversity index for species richness, and lineage-per-time plots showed that for basil, organically grown samples had a higher microbial diversity than conventionally grown samples. Edible flowers and basil are often grown using organic methods and are commonly consumed raw without any washing or cooking, to preserve aesthetic value, but these practices may pose a potential risk for food-borne illness. The baseline assessment, together with phylogenetic and statistical analyses, indicated possible microbial contamination in edible flowers and basil. The use of statistical estimation of molecular diversity based on the 16S rRNA sequences and lineage-per-time plots with phylogenetic analysis well served as a means for comparing microbial diversity in food samples between the growing methods (organic vs. conventional).


Sign in / Sign up

Export Citation Format

Share Document