Fraud Identification of Cow’s Milk in Buffalo’s Milk and It’s Products Using the Polymerase Chain Reaction

A duplex polymerase chain reaction (PCR) was developed to identify the milk of bovine and buffalo species in cheese products, particularly in mozzarella cheese, a typical Italian cheese made from buffalo's milk. Two sets of primers were designed on the basis of the alignment of the sequence codifying mitochondrial cyt b available in the GenBank database. The primers proved to be species-specific, giving rise to 279-bp (bovine) and 192-bp (buffalo) amplified fragments. Since the amplification conditions for bovine and buffalo primers were identical, a duplex PCR was successfully applied to identify the two species in a single reaction step. This technique, when used to test cheese products from the retail trade, allowed the detection of partial or even total substitution of cow's milk for buffalo's milk, in some cases in samples of cheese misleadingly labeled “pure buffalo” mozzarella.

Download Full-text

Using Polymerase Chain Reaction ( PCR) Technique For Detection E .coli O157:H7 BacteriaFrom Raw Cow's Milk and Local SOFT Chesses.

International Journal of Advanced Research ◽

10.21474/ijar01/1302 ◽

2016 ◽

Vol 4 (8) ◽

pp. 1046-1056

Author(s):

Mohammed Al-ayash. ◽

◽

Prof.Dr.WathiqA. AL-Daraghi. ◽

Keyword(s):

Polymerase Chain Reaction ◽

Cow’S Milk ◽

Chain Reaction ◽

Cow's Milk ◽

E Coli ◽

Polymerase Chain ◽

Raw Cow’S Milk

Download Full-text

Quantitative assessment of Lactococcus lactis subsp. cremoris present in artisanal raw cow’s milk cheese

Acta Veterinaria Brno ◽

10.2754/avb201887020189 ◽

2018 ◽

Vol 87 (2) ◽

pp. 189-195

Author(s):

Milena Alicja Stachelska

Keyword(s):

Polymerase Chain Reaction ◽

Lactococcus Lactis ◽

Dynamic Range ◽

Limit Of Detection ◽

Cow’S Milk ◽

Chain Reaction ◽

Cow's Milk ◽

Polymerase Chain ◽

Cheese Production ◽

Raw Cow’S Milk

Lactococcus lactis subsp. cremoris belongs to lactic acid bacteria that play a crucial role in cheese production and it is known to be beneficial to human health. The aim of the study was to establish a rapid and accurate quantitative real-time polymerase chain reaction (qPCR) method to detect and enumerate L. lactis subsp. cremoris in artisanal raw cow’s milk cheese. Artisanal raw cow’s milk cheese samples were used to check for presence and number of L. lactis subsp. cremoris strains. The method applies a set of target-specific PCR (polymerase chain reaction) primers and a fluorogenic probe, and amplifies a part of the LACR_RS01280 gene that encodes the aminoacetone oxidase family flavin adenine dinucleotide (FAD) binding enzyme. All 5 L. lactis subsp. cremoris strains examined were found to be qPCR positive. There was no signal recorded for 8 strains which belong to closely related species. The limit of detection amounted to ten copies per reaction and the assay indicated a linear dynamic range of seven logs. This method may be applied in detection and enumeration of L. lactis subsp. cremoris in cheese during its ripening. Moreover, it may be applied to examine the distribution of L. lactis subsp. cremoris during the cheese production and ripening.

Download Full-text

Development of a time-effective and highly specific quantitative real-time polymerase chain reaction assay for the identification of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus in artisanal raw cow’s milk cheese

Acta Veterinaria Brno ◽

10.2754/avb201887030301 ◽

2018 ◽

Vol 87 (3) ◽

pp. 301-308

Author(s):

Milena Alicja Stachelska ◽

Roberta Foligni

Keyword(s):

Polymerase Chain Reaction ◽

Real Time ◽

Streptococcus Thermophilus ◽

Lactobacillus Delbrueckii ◽

Cow’S Milk ◽

Chain Reaction ◽

Cheese Ripening ◽

Gene Copies ◽

Polymerase Chain ◽

Raw Cow’S Milk

The first objective of this work included the development of real-time polymerase chain reaction (RT-PCR) which is also known as quantitative polymerase chain reaction (qPCR) assays to quantify two species of lactic acid bacteria which play a very important role in cheese ripening: Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. The second objective was the comparison of qPCR and plate counts of these two species present in raw cow’s milk cheese samples during different stages of ripening. Thirty-three deoxyribonucleic acid (DNA) samples coming from seven different bacterial species, which were phylogenetically related or commonly isolated from raw milk and dairy products, were chosen as positive and negative controls. The qPCR assays showed a high quantification capacity characterised by their linearity (R2 > 0.998), PCR efficiencies which were within the range 78.0–90.0% for L. delbrueckii subsp. bulgaricus, and 93.6–100.5% for S. thermophilus, and quantification limit (103 gene copies/ml for L. delbrueckii subsp. bulgaricus and 10 gene copies/ml for S. thermophilus). The importance of our study is in the monitoring of changes in populations of L. delbrueckii subsp. bulgaricus and S. thermophilus contributing to cheese ripening using the newly designed qPCR assay.

Download Full-text

High performance Nanogold™-in situ hybridzation and its use in the detection of hybridized and PCR-amplified microscopical preparations

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100166944 ◽

1996 ◽

Vol 54 ◽

pp. 896-897

Author(s):

G. W. Hacker ◽

I. Zehbe ◽

J. Hainfeld ◽

A.-H. Graf ◽

C. Hauser-Kronberger ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Messenger Rna ◽

High Performance ◽

Detection System ◽

Direct Methods ◽

Genetic Alterations ◽

Chain Reaction ◽

Protein Encoding ◽

Polymerase Chain

In situ hybridization (ISH) with biotin-labeled probes is increasingly used in histology, histopathology and molecular biology, to detect genetic nucleic acid sequences of interest, such as viruses, genetic alterations and peptide-/protein-encoding messenger RNA (mRNA). In situ polymerase chain reaction (PCR) (PCR in situ hybridization = PISH) and the new in situ self-sustained sequence replication-based amplification (3SR) method even allow the detection of single copies of DNA or RNA in cytological and histological material. However, there is a number of considerable problems with the in situ PCR methods available today: False positives due to mis-priming of DNA breakdown products contained in several types of cells causing non-specific incorporation of label in direct methods, and re-diffusion artefacts of amplicons into previously negative cells have been observed. To avoid these problems, super-sensitive ISH procedures can be used, and it is well known that the sensitivity and outcome of these methods partially depend on the detection system used.

Download Full-text