Identification of Cow's Milk in “Buffalo” Cheese by Duplex Polymerase Chain Reaction

2002 ◽  
Vol 65 (2) ◽  
pp. 362-366 ◽  
Author(s):  
M. T. BOTTERO ◽  
T. CIVERA ◽  
A. ANASTASIO ◽  
R. M. TURI ◽  
S. ROSATI

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.

2018 ◽  
Vol 87 (2) ◽  
pp. 189-195
Author(s):  
Milena Alicja Stachelska

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.


2020 ◽  
Vol 48 (1) ◽  
pp. 62-72
Author(s):  
E. A. Ershova

Сalanoid copepods of the genus Pseudocalanus play an important role in the plankton communities of the Arctic and boreal seas, often dominating in numbers and constituting a significant proportion of the biomass of zooplankton. Despite their high presence and significance in the shelf plankton communities, species-specific studies of the biology of these are significantly hampered by extremely small morphological differences between them, especially at the juvenile stages, at which they are virtually indistinguishable. In this paper, we describe a new, routine and low-cost molecular method for identifying all Pseudocalanus species found in the Atlantic sector of the Arctic: the Arctic P. acuspes, P. minutus and the boreal P. moultoni and P. elongatus, and apply it to describe the relative distribution of these species in four locations of the Arctic and sub-Arctic. With this method, species-specific polymerase chain reaction (ssPCR), mass identification of individuals of any developmental stage, including nauplii, is possible. This method can serve as an excellent tool for studying the species-specific biology of this group, describing their life cycles, as well as monitoring changes in Arctic marine ecosystems under the influence of changing climate.


Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 4
Author(s):  
Oleg S. Alexandrov ◽  
Olga V. Razumova ◽  
Gennady I. Karlov

5S rDNA is organized as a cluster of tandemly repeated monomers that consist of the conservative 120 bp coding part and non-transcribed spacers (NTSs) with different lengths and sequences among different species. The polymorphism in the 5S rDNA NTSs of closely related species is interesting for phylogenetic and evolutional investigations, as well as for the development of molecular markers. In this study, the 5S rDNA NTSs were amplified with universal 5S1/5S2 primers in some species of the Elaeagnaceae Adans. family. The polymerase chain reaction (PCR) products of five Elaeagnus species had similar lengths near 310 bp and were different from Shepherdia canadensis (L.) Nutt. and Sh. argentea (Pusch.) Nutt. samples (260 bp and 215 bp, respectively). The PCR products were cloned and sequenced. An analysis of the sequences revealed that intraspecific levels of NTS identity are high (approximately 95–96%) and similar in the Elaeagnus L. species. In Sh. argentea, this level was slightly lower due to the differences in the poly-T region. Moreover, the intergeneric and intervarietal NTS identity levels were studied and compared. Significant differences between species (except E. multiflora Thunb. and E. umbellata Thunb.) and genera were found. Herein, a range of the NTS features is discussed. This study is another step in the investigation of the molecular evolution of Elaeagnaceae and may be useful for the development of species-specific DNA markers in this family.


2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Parastoo Hassani Abharian ◽  
Parvin Dehghan ◽  
Peyman Hassani Abharian ◽  
Sepideh Tolouei

  Background and Purpose: Candida dubliniensis is closely related to the most pathogenic and prevalent yeast, namely C. albicans. Candida species can opportunistically overgrow in vulnerable individuals and cause a variety of diseases. The current study aimed to identify and isolate C. dubliniensis species present in the Candida albicans species complex identified in the oral cavity of drug abusers. Materials and Methods: This study was conducted on 53 strains of C. albicans species complex, isolated from the oral mucosa of drug abusers in Isfahan, Iran. DNA extraction was accomplished through boiling procedure. Duplex polymerase chain reaction (PCR) was performed to amplify ITS1-5.8S-ITS2 region using four specific primers. Fungal species were identified based on the difference in the size of the bands created in the Agarose gel. Results: Out of the 53 isolates under study, 30 (56.6%) and 14 (26.4%) samples were identified as C. albicans and C. dubliniensis, respectively. In the remaining 9 samples (17%), both types of Candida species were confirmed. Conclusion: The findings of the present study revealed the presence of a noticeable amount of C. dubliniensis in the oral cavity of drug abusers. Therefore, the probable presence of this fungus should be considered during the examination of oral infection among this group. To date, no research has directly investigated this issue in Iran.


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