scholarly journals Detection of INVA Gene and Cytotoxin of Salmonella entertidis in Food Samples Using Molecular Methods

2021 ◽  
pp. 20-28
Author(s):  
Maha Almas ◽  
Usaal Tahir ◽  
Mariam Zameer ◽  
Muhammad Imtiaz Shafiq ◽  
Syeda Yumna Farrukh ◽  
...  
Keyword(s):  
Foodborne Pathogen ◽  
Food Samples ◽  
Human Beings ◽  
Inva Gene ◽  
Molecular Tests ◽  
Sds Page ◽  
Glucose Agar ◽  
Encoding Gene ◽  
Precautionary Measures ◽  
Enriched Cultures

Salmonella entertidis is a foodborne pathogen that causes various diseases in human beings worldwide. The toxin of Salmonella can cause infectious diseases. In this research project, Salmonella was detected through various microbial, biochemical and molecular tests in diverse food samples collected from highly populated, moderately populated and less populated areas of Lahore, Pakistan. Enriched cultures of all food samples such as apples, tomatoes, yogurt and mayonnaise was streaked on violet-red bile glucose agar, Simmon’s citrate agar and eosin-methylene blue agar (EMB).  Salmonella isolates were screened for the presence of toxin encoding gene through PCR. 27% apples, 19% tomatoes, 5% mayonnaise and 7% yogurt were found to be positive for INVA genes (invasion protein genes). In medical and pharmaceutical point of views the INVA gene can also help to develop specific medicines against salmonella. The cytotoxin that is protein in nature was confirmed by SDS PAGE in mayonnaise samples. This study illustrates that foods of highly populated areas are reservoir for Salmonella entertidis in Pakistan. There is need to develop specific drugs, precautionary measures to control salmonella and its disease.

Isolation of Enterobacter sakazakii from Stable Flies, Stomoxys calcitrans L. (Diptera: Muscidae)†

2006 ◽  
Vol 69 (3) ◽  
pp. 671-673 ◽  
Author(s):  
F. MRAMBA ◽  
A. BROCE ◽  
L. ZUREK
Keyword(s):  
16S Rdna ◽  
Foodborne Pathogen ◽  
Animal Manure ◽  
Stomoxys Calcitrans ◽  
Fecal Coliforms ◽  
Stable Fly ◽  
Enterobacter Sakazakii ◽  
Stable Flies ◽  
16S Rdna Pcr ◽  
Glucose Agar

Enterobacter sakazakii is an opportunistic foodborne pathogen that causes meningitis, enterocolitis, and sepsis, primarily in immunocompromised infants. Previously, it was suggested that stable flies, Stomoxys calcitrans, were a vector or reservoir of this pathogen. In our study, by means of a culturing approach combined with 16S rDNA PCR–restriction fragment length polymorphism genotyping and sequencing, we screened 928 individual stable flies collected in Kansas and Florida. Two stable flies (0.2%) were positive for E. sakazakii. In addition, 411 (44%) stable flies carried bacteria-forming red colonies (presumably enterics) on a violet red bile glucose agar (mean count = 6.4 × 104 CFU per fly), and 120 (13%) stable flies carried fecal coliforms (mean count = 8.7 × 103 CFU per fly). Sequencing of 16S rDNA showed that enterics from violet red bile glucose agar were represented by several genera, including Escherichia, Shigella, Providencia, Enterobacter, Pantoea, Proteus, Serratia, and Morganella. Our study shows that stable flies carry bacteria typically present in animal manure (a developmental site of stable fly larvae), which indicates that the natural reservoir of E. sakazakii is the digestive tract or manure of domestic animals. The low prevalence of E. sakazakii associated with stable flies suggests that stable flies do not play a major role as a reservoir or vector of this pathogen.

scholarly journals Screening for the Production and Characterization of L-asparaginase from Endophytic Fungi

2021 ◽  
Vol 8 (5) ◽  
pp. 168-173
Author(s):  
Harjeet Singh ◽  
Shweta Sao
Keyword(s):  
Lymphoblastic Leukemia ◽  
Fungal Endophytes ◽  
Erwinia Carotovora ◽  
Maximum Activity ◽  
Phenol Red ◽  
Human Beings ◽  
Ph Indicator ◽  
Carbon And Nitrogen ◽  
Sds Page ◽  
Secondary Neoplasm

L-asparaginase (EC 3.5.11. L-asparagine amidohydrolase) is first enzyme, studied very intensively in human beings with regard to its anti-tumor potential against tumor of lymphoid precursor, acute lymphoblastic leukemia (ALL). The current drugs are suffering from many side effects like immune suppression, infertility, secondary neoplasm. The immunogenic complications associated with its present microbial sources Escherichia coli; Erwinia carotovora limits its medicinal frontier. So there exists a need of switching to novel natural sources to serve as non-immunogenic and better production sources of L-asparaginase. In the present study, four cultures of fungal endophytes viz. TSF-1, TSF-2, TSF-3 and TSF-4 selected on the basis of primary and secondary screening was carried on with L-asparagine as a sole carbon and nitrogen source and phenol red as pH indicator. The maximum protein content was observed to be present in TSF-2 i.e. 2.727 mg /mL and possessed maximum activity of 6.054 Units/ml. Sample was separated by SDS-PAGE, stained by silver staining, showed a single band with molecular weight of approximately ~45kDa.

Occurrence and Characterization of Aeromonas Species in Pasteurized Milk and White Cheese in Rio De Janeiro, Brazil

1993 ◽  
Vol 56 (1) ◽  
pp. 62-65 ◽  
Author(s):  
ANGELA CÔRREA FREITAS ◽  
MARLY PAIVA NUNES ◽  
ARLETE MOREIRA MILHOMEM ◽  
ILVAN DELGADO RICCIARDI
Keyword(s):  
Rio De Janeiro ◽  
Foodborne Pathogen ◽  
Food Samples ◽  
High Rate ◽  
Most Probable Number ◽  
Aeromonas Species ◽  
Probable Number ◽  
Pasteurized Milk ◽  
Milk Samples ◽  
White Cheese

A total of 35 samples (1000 ml each) of pasteurized milk and 25 samples (100 g each) of white cheese purchased at supermarkets in Rio de Janeiro were analyzed for the presence of Aeromonas. Strains of Aeromonas were isolated from 28.5% of pasteurized milk and 32% of white cheese samples. Standard Plate counts in the pasteurized milk samples ranged from 7.2 × 10* to 2.5 × 105 CFU/ml. Total and fecal coliform counts in white cheese samples ranged from 1.9 × 10* to 2.4 × 105 most probable number per g and 3.2 × 102 to 1.2 × 105 most probable number per g, respectively. It was possible to identify Aeromonas caviae (58.9%), Aeromonas hydrophila (12.8%), and Aeromonas schubertii (2.5%) among the cultures isolated from pasteurized milk samples. Twenty-five percent of the strains could only be classified as Aeromonas spp. In white cheese samples, unclassified strains were the most frequent isolates (61.5%) followed by A. hydrophila (26.9%), A. caviae (7.6%) and Aeromonas sobria (3.8%). Only strains of A. hydrophila and A. sobria showed high rate of positive results when tested for the production of hemolysin, cytotoxin, and staphylolytic activity. Heat-stable enterotoxin and autoagglutination test did not correlate as virulence factors. The presence of Aeromonas species in refrigerated food samples suggests that this microorganism could be a potential foodborne pathogen, and dairy products may represent an important vehicle of its transmission.

scholarly journals Detection of Salmonella in Food Matrices, from Conventional Methods to Recent Aptamer-Sensing Technologies

Foods ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 371 ◽  
Author(s):  
Paniel ◽  
Noguer
Keyword(s):  
Food Processing ◽  
Foodborne Pathogen ◽  
High Specificity ◽  
Food Samples ◽  
Alternative Methods ◽  
High Throughput Analysis ◽  
Research Teams ◽  
Conventional Culture ◽  
Consumer Safety ◽  
Made In

Rapid detection of the foodborne pathogen Salmonella in food processing is of crucial importance to prevent food outbreaks and to ensure consumer safety. Detection and quantification of Salmonella species in food samples is routinely performed using conventional culture-based techniques, which are labor intensive, involve well-trained personnel, and are unsuitable for on-site and high-throughput analysis. To overcome these drawbacks, many research teams have developed alternative methods like biosensors, and more particularly aptasensors, were a nucleic acid is used as biorecognition element. The increasing interest in these devices is related to their high specificity, convenience, and relative rapid response. This review aims to present the advances made in these last years in the development of biosensors for the detection and the quantification of Salmonella, highlighting applications on meat from the chicken food chain.

scholarly journals Increased production of tyrosinase from Bacillus megaterium strain M36 by the response surface method

2016 ◽  
Vol 68 (3) ◽  
pp. 659-668 ◽  
Author(s):  
Ebrahim Valipour ◽  
Burhan Arikan
Keyword(s):  
Response Surface ◽  
Bacillus Megaterium ◽  
Initial Conditions ◽  
Basal Medium ◽  
Fold Increase ◽  
Molecular Tests ◽  
Bacterial Enzyme ◽  
Sds Page ◽  
Tyrosinase Enzyme ◽  
Actual Yield

The bacterial enzyme tyrosinase, with its high oxidizing capacity, can be applied in phenolic biotransformation, pharmaceutical, cosmetics and textile industries. In this research, a native Bacillus sp.-producing tyrosinase was isolated from a soil sample. The strain was identified by morphological, biochemical and molecular tests using bioinformatics analysis, and was named Bacillus megaterium strain M36. According to the blast analysis of 16S rDNA (1434 bp), the strain showed 99% identity with Bacillus megaterium DSM319. The production of tyrosinase from the isolated strain was optimized by classic and response surface methods (RSM). The optimal conditions for tyrosinase production by the strain were determined to be as follow: growth temperature 36?C, pH of medium 7.0, incubation time 16 h, with medium containing 0.4 mg/mL L-tyrosine, 0.05% yeast extract, 0.423% tryptone, 3.4% NaCl and 148.4 ?M CuSO4. Results of experiments performed under the optimized condition showed an actual yield of 0.522 IU of enzyme, while the result under the initial conditions using basal medium (before optimization) gave 0.0312 IU of enzyme (16.7-fold increase). SDS-PAGE analysis showed that the tyrosinase enzyme from Bacillus megaterium strain M36 is about 34 kDa.

scholarly journals Real-Time PCR Method for the Rapid Detection and Quantification of Pathogenic Staphylococcus Species Based on Novel Molecular Target Genes

Foods ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2839
Author(s):  
Eiseul Kim ◽  
Seung-Min Yang ◽  
Ji-Eun Won ◽  
Da-Young Kim ◽  
Da-Som Kim ◽  
...  
Keyword(s):  
Real Time ◽  
Target Genes ◽  
Foodborne Pathogen ◽  
Food Contamination ◽  
Disease Outbreaks ◽  
Molecular Target ◽  
Food Samples ◽  
Staphylococcus Capitis ◽  
Rapid Monitoring ◽  
Pure Cultures

Coagulase-positive Staphylococcus aureus is a foodborne pathogen considered one of the causes of food-related disease outbreaks. Like S. aureus, Staphylococcus capitis, Staphylococcus caprae, and S. epidermidis are opportunistic pathogens causing clinical infections and food contamination. The objective of our study was to develop a rapid, accurate, and monitoring technique to detect four Staphylococcus species in food. Four novel molecular targets (GntR family transcriptional regulator for S. aureus, phosphomannomutase for S. epidermidis, FAD-dependent urate hydroxylase for S. capitis, and Gram-positive signal peptide protein for S. caprae) were mined based on pan-genome analysis. Primers targeting molecular target genes showed 100% specificity for 100 non-target reference strains. The detection limit in pure cultures and artificially contaminated food samples was 102 colony-forming unit/mL for S. aureus, S. capitis, S. caprae, and S. epidermidis. Moreover, real-time polymerase chain reaction successfully detected strains isolated from various food matrices. Thus, our method allows an accurate and rapid monitoring of Staphylococcus species and may help control staphylococcal contamination of food.

scholarly journals Erwinia amylovora Enfeksiyonu Sonrası Elma, Armut ve Ayva Çeşitlerinde Konukçu Protein Miktarlarının Belirlenmesi

2014 ◽  
Vol 3 (3) ◽  
pp. 154
Author(s):  
Şerife Çetin ◽  
Kubilay Kurtuluş Baştaş
Keyword(s):  
Protein Content ◽  
Total Protein ◽  
Erwinia Amylovora ◽  
Bacterial Pathogen ◽  
Molecular Weights ◽  
Molecular Tests ◽  
Sds Page ◽  
Apple Cultivars ◽  
Blight Disease ◽  
Santa Maria

Fire blight disease caused by Erwinia amylovora is a destructive bacterial pathogen mainly on pears, apples and quinces from Rosaceae family. In this study, it was aimed determination of total protein amounts in different apple cultivars (Braeburn, Fuji, Gala and Golden), pear cultivars (Santa Maria and Williams) and quince cultivars (Eşme and Ekmek) in the infections of two virulent E. amylovora strains (Ea234-1 and Ea240-3) according as the time. It was taken leaf samples after leaf inoculation with E. amylovora (108 CFU ml-1) at 24th, 36th and 72nd hours. For verification of the infections, re-isolations were made from bacteria inoculated plants and the agent was identified as E. amylovora by biochemical, physiological and molecular tests. In determining the amounts of total protein and in the SDS-PAGE analyses were used Bradford and Laemmli methods, respectively, and absorbance values of protein extracts derived from the leaf samples taken, were obtained at 595 nm wavelength. According to the findings obtained; after infection of E. amylovora in the apple varieties comparing to controls, total protein concentrations at 24th hours increased and a decrease in the amount of 36th to 72nd hours and Braeburn has the highest protein content was determined. In the pear varieties, while total protein concentrations at 24th and 36th hours increased, a decrease in the amount of 72nd hour, and Santa Maria variety has the highest protein content was detected. In the quince varieties, total protein concentrations at 72th hour increased and Eşme variety has the highest protein content was identified. As a result of SDS-PAGE analysis, protein fractions which have different molecular weights were obtained. The protein bands were defined approximately 55-70 kDa and 35-55 kDa molecule weight on apple and quince varieties, respectively and also approx. 55-70 kDa in pear varieties.

scholarly journals DETECTION OF HBLD TOXIN GENE BY BACILLUS CEREUS ISOLATED FROM MEAT CURRY FOOD SAMPLES IN MALAYSIAN RESTAURANTS

2020 ◽  
Vol 4 (2) ◽  
pp. 68-72
Author(s):  
Marwan Msarah ◽  
Ahmed Alsier ◽  
Sahilah, A.M.
Keyword(s):  
Bacillus Cereus ◽  
Foodborne Pathogen ◽  
Food Poisoning ◽  
Egg Yolk ◽  
Food Samples ◽  
Blood Agar ◽  
Toxin Gene ◽  
Biochemical Tests ◽  
Isolation Medium ◽  
Hemolysin Bl

Bacillus cereus is a ubiquitous foodborne pathogen, can cause food poisoning, leading to infections, have two major types of food poisoning emetic and diarrheal. Foods rich in protein such as meat are associated with foodborne outbreaks of diarrhea caused by B. cereus. The aim of this study is to isolate and identify B. cereus from ready to eat (RTE) meat curry from restaurants in Malaysia and to detect hblD pathogenic gene of B. cereus isolates. Mannitol egg yolk polymyxin agar was used as a selective isolation medium. Commercially available kits and boiling methods were used for DNA extraction, samples acquired from restaurants were examined for the presence of Hemolysin BL gene by polymerase chain reaction (PCR). Among all isolates, twenty-four of B. cereus isolates detected for HBL enterotoxin production by the discontinuous pattern on HBL sheep blood agar then confirmed by biochemical tests. More than 58.33 % of the isolate showed discontinuous hemolysis pattern on HBl blood agar and 29.16% of the samples were shown positive for hblD gene that can cause diarrhea with the size of 807bp on gel. This study demonstrated that RTE meat curry was a potential source for entero-toxigenic B. cereus and the presence of the hblD toxin genes for the HBL complex in the isolates tested were highly associated. Therefore, these meat curry isolates should be regarded as potential toxin producers.

Enumerative Analysis of Salmonella in Outbreak-Associated Breaded and Frozen Comminuted Raw Chicken Products

2017 ◽  
Vol 80 (5) ◽  
pp. 814-818 ◽  
Author(s):  
Angela Catford ◽  
Kyle Ganz ◽  
Sandeep Tamber
Keyword(s):  
Foodborne Pathogen ◽  
Food Samples ◽  
Most Probable Number ◽  
Distribution Analysis ◽  
Probable Number ◽  
Contaminated Food ◽  
Foodborne Outbreaks ◽  
Low Levels ◽  
Data Gap ◽  
Pathogen Exposure

ABSTRACT A significant data gap exists with respect to the levels of pathogens in foods implicated in foodborne outbreaks. These data are essential for the quantification of pathogen exposure via the ingestion of contaminated food. Here we report the levels of the foodborne pathogen Salmonella in comminuted raw chicken products that had been breaded and then frozen. The products investigated were collected during four food safety investigations of foodborne outbreaks that occurred in Canada from 2014 to 2016. Most-probable-number (MPN) distribution analysis of the food samples revealed Salmonella levels of 0.0018 to 3 MPN/g, which is equivalent to 1 MPN per 0.33 to 556 g of product. These data suggest low levels of Salmonella may be associated with foodborne outbreaks.

scholarly journals A database for risk assessment and comparative genomic analysis of foodborne Vibrio parahaemolyticus in China

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Rui Pang ◽  
Yanping Li ◽  
Moutong Chen ◽  
Haiyan Zeng ◽  
Tao Lei ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Foodborne Pathogens ◽  
Vibrio Parahaemolyticus ◽  
Foodborne Pathogen ◽  
Genomic Analysis ◽  
Food Samples ◽  
Comparative Genomic ◽  
Genome Database ◽  
Scientific Database ◽  
Need To Evaluate

Abstract Vibrio parahaemolyticus is a major foodborne pathogen worldwide. The increasing number of cases of V. parahaemolyticus infections in China indicates an urgent need to evaluate the prevalence and genetic diversity of this pathogenic bacterium. In this paper, we introduce the Foodborne Vibrio parahaemolyticus genome database (FVPGD), the first scientific database of foodborne V. parahaemolyticus distribution and genomic data in China, based on our previous investigations of V. parahaemolyticus contamination in different kinds of food samples across China from 2011 to 2016. The dataset includes records of 2,499 food samples and 643 V. parahaemolyticus strains from supermarkets and marketplaces distributed over 39 cities in China; 268 whole-genome sequences have been deposited in this database. A spatial view on the risk situations of V. parahaemolyticus contamination in different food types is provided. Additionally, the database provides a functional interface of sequence BLAST, core genome multilocus sequence typing, and phylogenetic analysis. The database will become a powerful tool for risk assessment and outbreak investigations of foodborne pathogens in China.

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