Detection of Brucella organisms from Egyptian raw milk using cultural and molecular techniques

2020 ◽  
Vol 18 (2) ◽  
pp. 14-19
Author(s):  
Ibrahim Aman ◽  
Ibrahim AL-Hawary ◽  
Nashwa Helmy ◽  
Ahmed EL-Gushi
Keyword(s):  
Raw Milk ◽  
Molecular Techniques

Detection and Fate of Bacillus anthracis (Sterne) Vegetative Cells and Spores Added to Bulk Tank Milk†

2003 ◽  
Vol 66 (12) ◽  
pp. 2349-2354 ◽  
Author(s):  
MICHAEL L. PERDUE ◽  
JEFF KARNS ◽  
JIM HIGGINS ◽  
JO ANN VAN KESSEL
Keyword(s):  
Bacillus Anthracis ◽  
Protective Antigen ◽  
Lethal Factor ◽  
Raw Milk ◽  
Molecular Data ◽  
Molecular Techniques ◽  
Nucleotide Sequence Analysis ◽  
Vegetative Cells ◽  
Bulk Tank Milk ◽  
Bulk Tank

A preparation of Bacillus anthracis (Sterne strain) spores was used to evaluate commercially available reagents and portable equipment for detecting anthrax contamination by using real-time PCR and was used to assess the fate of spores added directly to bulk tank milk. The Ruggedized Advanced Pathogen Identification Device (RAPID) was employed to detect spores in raw milk down to a concentration of 2,500 spores per ml. Commercially available primers and probes developed to detect either the protective antigen gene or the lethal factor gene both provided easily read positive signals with the RAPID following extraction from milk with a commercially available DNA extraction kit. Nucleotide sequence analysis of the vrrA gene with the use of DNA extracted from spiked milk provided molecular data that readily identified the spores as B. anthracis with a 100% BLAST match to the Sterne and Ames strains and easily distinguished them from B. cereus. Physical-fate and thermal-stability studies demonstrated that spores and vegetative cells have a strong affinity for the cream fraction of whole milk. A single treatment at standard pasteurization temperatures, while 100% lethal to vegetative cells, had no effect on spore viability even 14 days after the treatment. Twenty-four hours after the first treatment, a second treatment at 72°C for 15 s reduced the viability of the population by ca. 99% but still did not kill all of the spores. From these studies, we conclude that standard pasteurization techniques for milk would have little effect on the viability of B. anthracis spores and that raw or pasteurized milk poses no obstacles to the rapid detection of the spores by molecular techniques.

scholarly journals Thermoduric psychrotrophic proteolytic microbiota from refrigerated raw milk

2017 ◽  
Vol 38 (1) ◽  
pp. 267 ◽  
Author(s):  
Jose Carlos Ribeiro Junior ◽  
Vanerli Beloti ◽  
Fernanda Pelisson Massi ◽  
Maria Helena Pelegrinelli Fungaro
Keyword(s):  
Shelf Life ◽  
Bacillus Pumilus ◽  
Raw Milk ◽  
Geotrichum Candidum ◽  
Molecular Techniques ◽  
Its2 Region ◽  
Rrna Gene ◽  
Pasteurized Milk ◽  
Heat Treated ◽  
Milk And Dairy Products

Thermoduric microorganisms may withstand high temperatures during the pasteurization of milk. Therefore, the microbiota in pasteurized milk consist of thermoduric microbes and directly influence the shelf-life of the milk. The aim of this study was to identify thermoduric psychrotrophic proteolytic microbiota in refrigerated raw milk. Twenty samples, previously heat-treated, were streaked and incubated at 7°C for 10 days. The strains isolated were streaked on milk agar to assess proteolytic activity and were initially analyzed morphologically by light microscopy and then by molecular techniques to identify the species. In 40% of the samples analyzed was observed only one bacterial growth and others 10 thermoduric psychrotrophic fungi. All isolates were proteolytic. The sequencing of 16S rRNA gene identified the bacterial strain as Bacillus pumilus and analysis of the ITS1-5.8S-ITS2 region of fungal isolates revealed the Cladosporium cladosporioides (60%), Curvularia geniculatus (10%), and the 3 remaining strains were identified as Geotrichum candidum (30%). This is a fist description of B. pumilus in Brazilian raw milk. Considering the spoilage potential of all isolates and of the fungi present in raw milk and their survival in pasteurized milk, it is extremely important to carry out further studies to your resistant to heat, their impact on the shelf-life of pasteurized milk, ultra-high temperature (UHT) milk and dairy products.

Diversity of lactic acid bacteria isolated from AOC Salers cheese

2004 ◽  
Vol 71 (2) ◽  
pp. 231-244 ◽  
Author(s):  
Cécile Callon ◽  
Liliane Millet ◽  
Marie-Christine Montel
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactobacillus Plantarum ◽  
Leuconostoc Mesenteroides ◽  
Raw Milk ◽  
Molecular Techniques ◽  
Lactobacillus Paracasei ◽  
Strain Collection ◽  
Natural Microflora ◽  
Leuconostoc Pseudomesenteroides

The objective of this work was to describe the diversity of lactic acid bacteria in traditional raw milk Salers cheeses at the species and strain levels. The characterization of 381 strains isolated during ripening and various strain collections was investigated using physiological analysis and molecular techniques: Rep-PCR, species and genus specific amplifications and the sequence analysis of 16S rDNA for strain typing and taxonomic identification. The strains belonged to Lactobacillus plantarum, Lactobacillus paracasei, Lactococcus lactis, Lactococcus garviae, Enterococcus faecalis, Enterococcus faecium, Leuconostoc mesenteroides, Leuconostoc pseudomesenteroides, Streptococcus salivarius, Streptococcus millieri, Streptococcus macedonicus and Pediococcus pentosaceus. A wide phenotypic and genomic heterogeneity was observed within the different species (Lactobacillus plantarum, Lactobacillus paracasei and Leuconostoc mesenteroides) according to the origin and the time of ripening. The natural microflora was different from strain collection and each method must be combined to identify and characterize natural microflora. This study revealed the low selectivity of selective media used for the isolation of different groups of lactic acid bacteria except the Facultatively Heterofermentative lactobacilli medium selecting mesophile lactobacilli and SB medium selective for Enterococcus. The study reveals, for the first time, the microbial lactic acid bacteria community of Salers cheese and its diversity. A better knowledge of microbial flora will be useful to improve understanding of sensory quality of cheeses.

scholarly journals Advanced Identification and Characterization of Listeria Species in Egyptian Local Soft Cheese

2020 ◽  
pp. 11-18
Author(s):  
Amany N. Dapgh ◽  
A. A. ELGedawy ◽  
Hussien A. Abouelhag ◽  
Asmaa S. Mansour ◽  
E. S. Gaber ◽  
...  
Keyword(s):  
Public Health ◽  
Antimicrobial Susceptibility ◽  
Raw Milk ◽  
Molecular Techniques ◽  
Health Concern ◽  
Public Health Concern ◽  
Advanced Technique ◽  
Soft Cheese ◽  
Vitek 2 ◽  
Species Specific

Aims: one of the most important foodborne microorganisms is the Gram’s positive environmental wide spread Listeria spp. As the Listeria may be considered a public health concern so there is in needing to rapid, precise and reliable diagnosis of the organism in consumed food. The present study aimed to survey the presence of Listeria spp. among two popular consuming Egyptian white soft cheese using advanced biochemical, antibiotic susceptibility and molecular techniques. Methodology: Listeria spp. was investigated in 155 samples of two white soft cheeses (70 kareish cheese and 85 Damietta cheese) collected from street vendors and retail markets in Giza. The existence of Listeria spp. was tested through cultural and the identification was confirmed biochemically by Vitek2 compact system as well as molecular identification via diplex real time PCR using species specific primers. Results: The results of the study revealed the isolation of two Listeria spp. in a total number of 22 from155 samples (14.19%); 14 isolate out of 70 (20%) Kareish cheese while 8 isolates out of 85 (9.4%) Damietta cheese's samples. The 22 Listeria spp. isolates were differentiated into L. innocua 15 (68.18%), and L. monocytogenes 7 (31.81%) also their antimicrobial susceptibility was declared using advanced Vitek-2 compact system. The two Listeria spp. isolates were definitely confirmed by using diplex DNA hybridization real PCR technique. Conclusion: Soft raw milk based cheese is a popular food in Egypt and looked on as a risk for foodborne bacteria contamination. The data of this study pointed out that there is a potential risk of infection with Listeria, especially the public health concern L. monocytogenes. The current study presented Vitek-2 compact system as advanced technique for not only for identification and differentiation of Listeria strains but also for their antimicrobial susceptibility. Furthermore the using of diplex real PCR technique gives a chance for quick and precise identification.

Multimode light microscopy and fluorescence-based reagents as tools for the study of chemical and molecular dynamics of living cells and tissues

1992 ◽  
Vol 50 (1) ◽  
pp. 418-419
Author(s):  
D. L. Taylor
Keyword(s):  
Living Cells ◽  
Cellular Level ◽  
Molecular Techniques ◽  
Cellular Functions ◽  
Macromolecular Assemblies ◽  
Cell Functions ◽  
Molecular Events ◽  
Yield Information ◽  
Full Knowledge ◽  
Structural Methods

Cells function through the complex temporal and spatial interplay of ions, metabolites, macromolecules and macromolecular assemblies. Biochemical approaches allow the investigator to define the components and the solution chemical reactions that might be involved in cellular functions. Static structural methods can yield information concerning the 2- and 3-D organization of known and unknown cellular constituents. Genetic and molecular techniques are powerful approaches that can alter specific functions through the manipulation of gene products and thus identify necessary components and sequences of molecular events. However, full knowledge of the mechanism of particular cell functions will require direct measurement of the interplay of cellular constituents. Therefore, there has been a need to develop methods that can yield chemical and molecular information in time and space in living cells, while allowing the integration of information from biochemical, molecular and genetic approaches at the cellular level.

Use of Raw Milk Persists Despite Rabies Scare

2006 ◽  
Vol 40 (11) ◽  
pp. 21
Author(s):  
JOHN R. BELL
Keyword(s):  
Raw Milk

Characterisation of Type 2N von Willebrand Disease Using Phenotypic and Molecular Techniques

1996 ◽  
Vol 75 (06) ◽  
pp. 959-964 ◽  
Author(s):  
I M Nesbitt ◽  
A C Goodeve ◽  
A M Guilliatt ◽  
M Makris ◽  
F E Preston ◽  
...  
Keyword(s):  
Direct Sequencing ◽  
Von Willebrand Disease ◽  
Molecular Techniques ◽  
Haemophilia A ◽  
Binding Region ◽  
Gene Encoding ◽  
Covalently Linked ◽  
Von Willebrand ◽  
Willebrand Factor

Summaryvon Willebrand factor (vWF) is a multimeric glycoprotein found in plasma non covalently linked to factor VIII (FVIII). Type 2N von Willebrand disease (vWD) is caused by a mutation in the vWF gene that results in vWF with a normal multimeric pattern, but with reduced binding to FVIII.We have utilised methods for the phenotypic and genotypic detection of type 2N vWD. The binding of FVIII to vWF in 69 patients, 36 with type 1 vWD, 32 with mild haemophilia A and one possible haemophilia A carrier with low FVIII levels was studied. Of these, six were found to have reduced binding (five type 1 vWD, one possible haemophilia A carrier), DNA was extracted from these patients and exons 18-23 of the vWF gene encoding the FVIII binding region of vWF were analysed. After direct sequencing and chemical cleavage mismatch detection, a Thr28Met mutation was detected in two unrelated individuals, one of whom appears to be a compound heterozygote for the mutation and a null allele. No mutations were found in the region of the vWF gene encoding the FVIII binding region of vWF in the other four patients

Raw milk cheese as a potential infection source of pathogenic and toxigenic food born pathogens

2020 ◽  
Author(s):  
Marita Vedovelli CARDOZO ◽  
Natalia NESPOLO ◽  
Tammy Chioda DELFINO ◽  
Camila Chioda de ALMEIDA ◽  
Lucas José Luduverio PIZAURO ◽  
...  
Keyword(s):  
Raw Milk ◽  
Infection Source ◽  
Raw Milk Cheese

The comparative study among the MRSAcin, Nisin A and vancomycin, on biofilm formation by Methicillin resistance Staphylococcus aureus isolated from food sources.

2019 ◽  
Vol 9 (o3) ◽  
Author(s):  
¹Hind H. Muunim ◽  
Muna T Al-Mossawei ◽  
Mais Emad Ahmed
Keyword(s):  
Biofilm Formation ◽  
Methicillin Resistance ◽  
Microbial Control ◽  
Antibiotic Sensitivity ◽  
Raw Milk ◽  
Sensitivity Test ◽  
Food Sources ◽  
Resistant Bacteria ◽  
Biochemical Tests ◽  
Food Preservatives

Biofilms formation by pathogens microbial Control considered important in medical research because it is the hazarded virulence factor leading to becoming difficult to treat because of its high resistance to antimicrobials. Glycopeptide antibiotic a (Vancomycin) and the commercial bacteriocin (Nisin A) were used to comparative with purification bacteriocin (MRSAcin) against MRSA biofilm. One hundred food samples were collected from Baghdad markets from July 2016 to September 2016, including (cheese, yogurt, raw milk, fried meat, grilled meat, and beef burger). All samples were cultures; S. aureus was confirmation by macroscopic culture and microscopic examination, in addition to biochemical tests. Methicillin resistance S. asureus (MRSA) were identification by antibiotic sensitivity test (AST), Vitek 2 system. The result shown the 60(60%) isolate were identified as S. aureus and 45(75%) gave positive result as MRSA isolate, M13 isolate was chosen as MRSA isolates highest biofilm formation for treatment with MRSAcin, Nisin A(bacteriocin) and Vancomycin (antibiotic) to compared the more antimicrobial have bacteriocidal effect. The sensitivity test uses to determine the effect of MRSAcin, Nisin A, and Vancomycin MIC on MRSA planktonic cell by (WDA). The new study shows the impacts of new kind Pure Bacteriocins (MRSAcin) from methicillin-resistant S. aureus (MRSA) highly effects then (Vancomycin and Nisin A) at different concentration. In a current study aimed to suggest new Bacteriocin is potent highly for the treatment of resistant bacteria biofilm infections in food preservatives

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