scholarly journals Usefulness of Multiplex Real-Time PCR for Simultaneous Pathogen Detection and Resistance Profiling of Staphylococcal Bacteremia

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yousun Chung ◽  
Taek Soo Kim ◽  
Young Gi Min ◽  
Yun Ji Hong ◽  
Jeong Su Park ◽  
...  
Keyword(s):  
16S Rrna ◽  
Real Time ◽  
Real Time Pcr ◽  
Pathogen Detection ◽  
Methicillin Resistance ◽  
Blood Cultures ◽  
Pcr Assay ◽  
Accurate Identification ◽  
Essential Information ◽  
Methicillin Resistant

Staphylococci are the leading cause of nosocomial blood stream infections. Fast and accurate identification of staphylococci and confirmation of their methicillin resistance are crucial for immediate treatment with effective antibiotics. A multiplex real-time PCR assay that targetsmecA,femAspecific forS. aureus,femAspecific forS. epidermidis,16S rRNAfor universal bacteria, and16S rRNAspecific for staphylococci was developed and evaluated with 290 clinical blood culture samples containing Gram-positive cocci in clusters (GPCC). For the 262 blood cultures identified to the species level with the MicroScan WalkAway system (Siemens Healthcare Diagnostics, USA), the direct real-time PCR assay of positive blood cultures showed very good agreement for the categorization of staphylococci into methicillin-resistantS. aureus(MRSA), methicillin-susceptibleS. aureus(MSSA), methicillin-resistantS. epidermidis(MRSE), methicillin-susceptibleS. epidermidis(MSSE), methicillin-resistant non-S. epidermidisCoNS (MRCoNS), and methicillin-susceptible non-S. epidermidisCoNS (MSCoNS) (κ=0.9313). The direct multiplex real-time PCR assay of positive blood cultures containing GPCC can provide essential information at the critical point of infection with a turnaround time of no more than 4 h. Further studies should evaluate the clinical outcome of using this rapid real-time PCR assay in glycopeptide antibiotic therapy in clinical settings.

Design and Validation of a Novel Multiplex Real-Time PCR Assay for Vibrio Pathogen Detection

2011 ◽  
Vol 74 (6) ◽  
pp. 939-948 ◽  
Author(s):  
ROBERT S. TEBBS ◽  
PIUS M. BRZOSKA ◽  
MANOHAR R. FURTADO ◽  
OLGA V. PETRAUSKENE
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Pathogen Detection ◽  
Nearest Neighbor ◽  
Vibrio Vulnificus ◽  
Molecular Techniques ◽  
Pcr Assay ◽  
Accurate Identification ◽  
Vibrio Pathogens ◽  
Pathogenic Vibrios

Three species—Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus—account for the majority of vibrio infections in humans. Rapid and accurate identification of Vibrio species has been problematic because phenotypic characteristics are variable within species. Additionally, biochemical identification and confirmation require 2 or more days to complete. Rapid and sensitive molecular techniques for the detection of vibrio pathogens would be useful for the surveillance and management of outbreaks. To facilitate the identification of human-pathogenic species, we designed and validated a highly sensitive, specific, and robust multiplex real-time PCR assay to identify V. cholerae, V. parahaemolyticus, and V. vulnificus using a four-dye configuration in a convenient lyophilized format. Multiple Vibrio strains were sequenced to verify candidate target TaqMan sites. Several individual assays within the multiplex contain multiple primers or probes to ensure detection of polymorphic variants. V. cholerae, V. parahaemolyticus, and V. vulnificus were detected either individually or in mixtures at ≤30 genomic copies. V. cholerae was specifically detected in the presence or absence of Vibrio mimicus. The Vibrio multiplex assay showed 100% specificity to all targets analyzed and no detection of nearest neighbor strains. Each assay exhibited 100% ± 10% efficiency. Multiplex real-time PCR can simplify pathogen detection and reduce costs per test since three species can be analyzed in a single reaction tube. Rapid and accurate detection of pathogenic vibrios in shellfish or seawater samples will improve the microbiological safety of seafood for consumers.

scholarly journals Multiplex Real-Time PCR Assay for Rapid Detection of Methicillin-Resistant Staphylococci Directly from Positive Blood Cultures

2014 ◽  
Vol 52 (6) ◽  
pp. 1911-1920 ◽  
Author(s):  
H.-y. Wang ◽  
S. Kim ◽  
J. Kim ◽  
S.-D. Park ◽  
Y. Uh ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Rapid Detection ◽  
Blood Cultures ◽  
Pcr Assay ◽  
Methicillin Resistant

scholarly journals Duplex Real-Time PCR Assay for Rapid Detection of Ampicillin-Resistant Enterococcus faecium

2004 ◽  
Vol 48 (2) ◽  
pp. 556-560 ◽  
Author(s):  
Stein Christian Mohn ◽  
Arve Ulvik ◽  
Roland Jureen ◽  
Rob J. L. Willems ◽  
Janetta Top ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Enterococcus Faecium ◽  
Rapid Detection ◽  
Resistant Bacteria ◽  
Pcr Assay ◽  
Culture Methods ◽  
Accurate Identification ◽  
Antibiotic Resistant ◽  
Highly Correlated

ABSTRACT Rapid and accurate identification of carriers of resistant microorganisms is an important aspect of efficient infection control in hospitals. Traditional identification methods of antibiotic-resistant bacteria usually take at least 3 to 4 days after sampling. A duplex real-time PCR assay was developed for rapid detection of ampicillin-resistant Enterococcus faecium (ARE). Primers and probes that are used in this assay specifically detected the d-Ala-d-Ala ligase gene of E. faecium and the modified penicillin-binding protein 5 gene (pbp5) carrying the Glu-to-Val substitution at position 629 (Val-629) in a set of 129 tested E. faecium strains with known pbp5 sequence. Presence of the Val-629 in the strain set from 11 different countries was highly correlated with ampicillin resistance. In a screening of hospitalized patients, the real-time PCR assay yielded a sensitivity and a specificity for the detection of ARE colonization of 95% and 100%, respectively. The results were obtained 4 h after samples were harvested from overnight broth of rectal swab samples, identifying both species and the resistance marker mutation in pbp5. This novel assay reliably identifies ARE 2 to 3 days more quickly than traditional culture methods, thereby increasing laboratory throughput, making it useful for rectal screening of ARE. The assay demonstrates the advantages of real-time PCR for detection of nosocomial pathogens.

Rapid real-time PCR assay for detecting Salmonella in raw and ready-to-eat meats

2008 ◽  
Vol 56 (4) ◽  
pp. 451-458 ◽  
Author(s):  
Jitu Patel ◽  
Arvind Bhagwat
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Pathogen Detection ◽  
Molecular Beacon ◽  
False Negative ◽  
Detection Methods ◽  
Time Data ◽  
Pcr Assay ◽  
Serovar Typhimurium ◽  
Meat Samples

A real-time PCR assay was evaluated for the rapid detection (10 h) ofSalmonellain meats using molecular beacon probes available as a commercial kit (iQ-Check, Bio-Rad laboratories). Raw (chicken, pork) and ready-to-eat (RTE) meats were artificially contaminated withSalmonella entericaserovar Typhimurium at the estimated level of 2 to 4 cells per 25 g. After 8 h of pre-enrichment in buffered peptone water, a molecular beacon-based PCR assay was performed to detect contamination in raw and RTE meats. The sensitivity and accuracy of the assay were compared with the conventional USDA microbiological procedure. Comparative evaluation of the USDA procedure with the rapid PCR assay for meat samples (n = 63) revealed 1 false negative pork sample with the PCR assay. All uninoculated controls (n = 34) but one sample were negative by both the 10-h PCR assay and the USDA procedure. Developing rapid pathogen detection methods with shorter pre-enrichment times (8-h) and real-time data monitoring capabilities will benefit the industry in preventing recall of contaminated meats by stopping the contaminated products from being introduced into the marketplace.

scholarly journals Development of qualitative methods of bifidobacterium bifidum in probiotic with Real-time PCR method

2018 ◽  
Vol 1 (1) ◽  
pp. 13-17
Author(s):  
Trong Pham Nhu ◽  
Long Le Thanh ◽  
Trung Nguyen Thanh ◽  
Yen Ta Thi ◽  
Loan Pham Thi ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Dairy Products ◽  
Food Additives ◽  
Bifidobacterium Bifidum ◽  
Pcr Assay ◽  
Accurate Identification ◽  
Powdered Milk ◽  
Pcr Method

Bifidobacterium strains with probiotic effects have been widely used in dairy products, food additives and pharmaceuticals. Especially, Bifidobacterium bifidum (B. bifidum) is usually presented into food products such as functional food. However, it is difficult to detect, and quantify B. bifidum in a sample with a combination of different probiotics. In Vietnam, there is no official standard method to identify and quantify B. bifidum in the sample with the mix of probiotic species. To fulfil the requirements of a robust quality management, we have developed a quantitative real-time PCR assay based on groEL gene for accurate identification and quantification of Bifidobacterium bifidum. The developed assay allows an unambiguous speciesspecific detection. We built the real-time PCR method to detect and identify B. bifidum in functional and supplemented food with specific up to 100% and reproducibility (SR<0.25) suitable with Annex F AOAC: 2016. This real-time PCR method is rapidly and effectively than conventional method. It takes only 24 hours to detect and identify B. bifidum in compare with at least a period of 3-5 days for conventional methods. The low quantitative limit is 105 CFU/g/mL, which is consistent with probiotic and powdered milk products with a declared quality of more than 106 CFU/g/mL.

scholarly journals A real-time PCR for the differentiation of typhoidal and non-typhoidal Salmonella

2019 ◽  
Author(s):  
Satheesh Nair ◽  
Vineet Patel ◽  
Tadgh Hickey ◽  
Clare Maguire ◽  
David R Greig ◽  
...  
Keyword(s):  
Public Health ◽  
Real Time ◽  
Real Time Pcr ◽  
Genomic Analysis ◽  
Rapid Identification ◽  
Specific Gene ◽  
Whole Genome ◽  
Pcr Assay ◽  
Gene Encoding ◽  
Accurate Identification

AbstractRapid and accurate differentiation of Salmonella spp. causing enteric fever from non-typhoidal Salmonella is essential for clinical management of cases, laboratory risk management and implementation of public health measures. Current methods used for confirmation of identification including biochemistry and serotyping as well as whole genome sequencing analyses, takes several days. Here we report the development and evaluation of a real-time PCR assay that can be performed directly on crude DNA extracts from bacterial colonies, for the rapid identification of typhoidal and non-typhoidal Salmonella.This novel two-hour assay identifies the genus Salmonella by detecting the ttr gene, encoding tetrathionate reductase, and defines typhoidal Salmonella by the detection of S. Typhi and Paratyphi-specific gene combinations. PCR assay performance was determined using 211 clinical cultures of Salmonella (114 non-typhoidal and 97 Typhoidal strains) and 7 clinical non-Salmonella cultures. In addition, the specificity of the assay was evaluated in silico using a diverse in-house collection of 1882 Salmonella whole genome sequences. The real-time PCR results for 218 isolates and the genomic analysis of the 1882 isolates produced 100% sensitivity and 100% specificity (based on a 7 gene profile) for identifying typhoidal Salmonella compared to the Salmonella whole genome sequening identification methods currently used at Public Health England.This paper describes a robust real-time PCR assay for the rapid, accurate identification of typhoidal and non-typhoidal Salmonella which will be invaluable for the urgent screening of isolates from symptomatic individuals, the safe processing of isolates in laboratories and for assisting the management of public health risks.

Prospective Clinical Evaluation of the Accuracy of 16S rRNA Real-Time PCR Assay for the Diagnosis of Melioidosis

2007 ◽  
Vol 77 (5) ◽  
pp. 814-817 ◽  
Author(s):  
Narisara Chantratita ◽  
Wasun Chantratita ◽  
Vanaporn Wuthiekanun ◽  
Nicholas P. J. Day ◽  
Direk Limmathurotsakul ◽  
...  
Keyword(s):  
16S Rrna ◽  
Real Time ◽  
Clinical Evaluation ◽  
Real Time Pcr ◽  
Pcr Assay
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