Identification of starter cultures in thermally treated plain yogurt using gene probes and polymerase chain reaction

1996 ◽  
Vol 63 (4) ◽  
pp. 607-613 ◽  
Author(s):  
Sonja Lick ◽  
Martina Keller ◽  
Uli Krusch ◽  
Knut J. Heller
Keyword(s):  
Polymerase Chain Reaction ◽  
Streptococcus Thermophilus ◽  
Starter Cultures ◽  
Lactobacillus Delbrueckii ◽  
Agarose Gel Electrophoresis ◽  
Chain Reaction ◽  
Specific Pcr ◽  
Specific Hybridization ◽  
Polymerase Chain ◽  
Species Specific

SummaryPlain yogurts (set type) fermented by three different starter cultures were subjected to different heat treatments (20 s at 72, 80 or 100 ·C, or 30 min at 60, 70, 80 or 100 ·C). DNA was extracted from each yogurt and analysed by agarose gel electrophoresis, by species-specific hybridization and by primer-specific polymerase chain reaction (PCR). Obvious degradation of DNA could be observed after heating at 80 ·C for 30 min and at 100 ·C for 20 s and 30 min. Identification ofLactobacillus delbrueckiiusing a species-specific hybridization fragment could be carried out in yogurt treated at 100 ·C for 20 s or for 30 min at lower temperatures. After treatment for 30 min at 100 ·C identification by hybridization was no longer possible. However, under the same conditions identification of starter microorganisms was still possible by primer-specific PCR, and this was demonstrated as an example forStreptococcus thermophilus.

Rapid Detection and Identification of Lactobacillus spp. in Dairy Products by Using the Polymerase Chain Reaction

1996 ◽  
Vol 59 (10) ◽  
pp. 1031-1036 ◽  
Author(s):  
MARYANNE DRAKE ◽  
CHRISTOPHER L. SMALL ◽  
KEMET D. SPENCE ◽  
BARRY G. SWANSON
Keyword(s):  
Polymerase Chain Reaction ◽  
Dairy Products ◽  
Lactobacillus Helveticus ◽  
Lactobacillus Delbrueckii ◽  
Lactobacillus Species ◽  
Chain Reaction ◽  
Bacterial Dna ◽  
Detection And Identification ◽  
Polymerase Chain ◽  
Species Specific

Species-specific primers for use in the polymerase chain reaction (PCR) were designed to differentially amplify DNA from the common dairy lactobacillus species Lactobacillus casei, Lactobacillus delbrueckii, Lactobacillus helveticus, and Lactobacillus acidophilus. A method for rapid extraction of bacterial DNA from dairy products was developed. The sensitivity of bacterial DNA extraction from food and subsequent amplification by PCR was 100 cells total. Lactobacillus DNA was extracted and identified from commercial yoghurts, acidophilus milk, and cheeses. The methodology allows the presumptive identification of dairy lactobacilli in less than 6 hours.

Serosurvey of AntiBabesia Antibodies in Stray Dogs and American Pit Bull Terriers and American Staffordshire Terriers From North Carolina

2003 ◽  
Vol 39 (6) ◽  
pp. 551-557 ◽  
Author(s):  
Adam J. Birkenheuer ◽  
Michael G. Levy ◽  
Martha Stebbins ◽  
Matthew Poore ◽  
Edward Breitschwerdt
Keyword(s):  
North Carolina ◽  
Polymerase Chain Reaction ◽  
Deoxyribonucleic Acid ◽  
Babesia Species ◽  
Chain Reaction ◽  
Babesia Gibsoni ◽  
Stray Dogs ◽  
Specific Pcr ◽  
Polymerase Chain ◽  
Species Specific

Stray dogs (n=359) and kennel dogs (n=149) from North Carolina were tested for evidence of antiBabesia antibodies. AntiBabesia antibodies were detected in 21/359 and 22/149 of the stray and kennel dogs, respectively. A total of 57 dogs from both groups were tested for babesiasis by light microscopy and polymerase chain reaction (PCR). Babesia deoxyribonucleic acid (DNA) was detected in 3/28 of the stray dogs and 14/29 of the kennel dogs. When Babesia DNA was detected by PCR, the species-specific PCR results differed from the Babesia species antibody titer results in 6/17 of the PCR-positive dogs. There was no association between antiBabesia antibodies and the presence of ticks. There are currently Babesia gibsoni epizootics affecting American pit bull terrier kennels.

scholarly journals 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

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.

Routine identification of four sympatric species of calanoid copepods Pseudocalanus spp. in the Atlantic Arctic using a species-specific polymerase chain reaction

2020 ◽  
Vol 48 (1) ◽  
pp. 62-72
Author(s):  
E. A. Ershova
Keyword(s):  
Polymerase Chain Reaction ◽  
Life Cycles ◽  
The Arctic ◽  
Relative Distribution ◽  
Chain Reaction ◽  
Specific Polymerase Chain Reaction ◽  
Routine Identification ◽  
Polymerase Chain ◽  
Species Specific ◽  
Plankton Communities

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.

scholarly journals A Comparative Study of 5S rDNA Non-Transcribed Spacers in Elaeagnaceae Species

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 4
Author(s):  
Oleg S. Alexandrov ◽  
Olga V. Razumova ◽  
Gennady I. Karlov
Keyword(s):  
Polymerase Chain Reaction ◽  
Molecular Markers ◽  
Dna Markers ◽  
5S Rdna ◽  
Chain Reaction ◽  
Closely Related Species ◽  
Pcr Products ◽  
Polymerase Chain ◽  
Species Specific ◽  
Shepherdia Canadensis

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.

scholarly journals Use of the polymerase chain reaction for detection of Fusarium graminearum in bulgur wheat

2012 ◽  
Vol 32 (1) ◽  
pp. 201-208 ◽  
Author(s):  
Carla Bertechini Faria ◽  
Giovana Caputo Almeida-Ferreira ◽  
Karina Bertechine Gagliardi ◽  
Tatiane Cristina Albuquerque Alves ◽  
Dauri José Tessmann ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Fusarium Graminearum ◽  
Genomic Dna ◽  
Solid Medium ◽  
Food Contamination ◽  
Chain Reaction ◽  
Specific Pcr ◽  
Culture Characteristics ◽  
Mycotoxigenic Fungi ◽  
Polymerase Chain

The detection of mycotoxigenic fungi in foodstuff is important because their presence may indicate the possible associated mycotoxin contamination. Fusarium graminearum is a wheat pathogen and a producer of micotoxins. The polymerase chain reaction (PCR) has been employed for the specific identification of F. graminearum. However, this methodology has not been commonly used for detection of F. graminearum in food. Thus, the objective of the present study was to develop a molecular methodology to detect F. graminearum in commercial samples of bulgur wheat. Two methods were tested. In the first method, a sample of this cereal was contaminated with F. graminearum mycelia. The genomic DNA was extracted from this mixture and used in a F. graminearum specific PCR reaction. The F. graminearum species was detected only in samples that were heavily contaminated. In the second method, samples of bulgur wheat were inoculated on a solid medium, and isolates having F. graminearum culture characteristics were obtained. The DNA extracted from these isolates was tested in F. graminearum specific PCR reactions. An isolate obtained had its trichothecene genotype identified by PCR. The established methodology could be used in surveys of food contamination with F. graminearum.

Human papillomavirus typing with GP5+/6+ polymerase chain reaction reverse line blotting and with commercial type-specific PCR kits

2006 ◽  
Vol 36 (2) ◽  
pp. 126-132 ◽  
Author(s):  
Anna Gillio-Tos ◽  
Laura De Marco ◽  
Valeria Ghisetti ◽  
Peter J.F. Snijders ◽  
Nereo Segnan ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Human Papillomavirus ◽  
Chain Reaction ◽  
Reverse Line Blotting ◽  
Specific Pcr ◽  
Polymerase Chain

Microsporidial infections due toEncephalitozoon intestinalisin non-HIV-infected patients with chronic diarrhoea

2011 ◽  
Vol 140 (10) ◽  
pp. 1773-1779 ◽  
Author(s):  
J. YAKOOB ◽  
Z. ABBAS ◽  
M. ASIM BEG ◽  
W. JAFRI ◽  
S. NAZ ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Stool Examination ◽  
Chronic Diarrhoea ◽  
Healthy Controls ◽  
Chain Reaction ◽  
Specific Primers ◽  
Specific Pcr ◽  
Stool Samples ◽  
Polymerase Chain ◽  
Species Specific

SUMMARYWe determined the prevalence of microsporidiaEnterocytozoon(Ent.)bieneusiandEncephalitozoon(E.)intestinalisinfection in patients with chronic diarrhoea and hepatocellular carcinoma (HCC). A total of 330 stool samples were examined from 171 (52%) patients with chronic diarrhoea, 18 (5%) with HCC while 141 (43%) were controls. Stool microscopy, polymerase chain reaction (PCR) with species-specific primers forEnt. bieneusiandE. intestinalisand sequencing were carried out. Microsporidia were found by trichrome staining in 11/330 (3%) andE. intestinalisby PCR in 13/330 (4%) whileEnt. bieneusiwas not detected. PCR forE. intestinaliswas positive in 8/171 (5%) stool samples from patients with chronic diarrhoea, 2/141 (1·4%) samples from healthy controls and in 3/18 (17%) samples from patients with HCC. In the chronic diarrhoea group,E. intestinaliswas positive in 4/171 (2·3%) (P=0·69) stool samples compared to 2/18 (11%) (P=0·06) in the HCC group and 2/141 (1·4%) from healthy controls.E. intestinalisinfection was significantly associated with chronic diarrhoea and HCC in these patients who were negative for HIV. Stool examination with trichrome or species-specific PCR for microsporidia may help establish the cause of chronic diarrhoea.

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