scholarly journals A simple multiplex polymerase chain reaction assay for rapid identification of the common pathogenic dermatophytes:Trichophyton interdigitale, Trichophyton rubrum, and Epidermophyton floccosum

Author(s):  
Sama Faramarzi ◽  
Marjan Motamedi ◽  
Ali Rezaei-Matehkolaei ◽  
Shima Aboutalebian ◽  
Saham Ansari ◽  
...  

Background and Purpose: The most common etiological agents of human dermatophytosis in various parts of the world are Trichophyton rubrum, Trichophyton interdigitale, and Epidermophyton floccosum. The main aim of this study was to design and evaluate a simple and straightforward multiplex polymerase chain reaction (PCR)assay for reliable identification/differentiation of these species in clinical isolates. Materials and Methods: The reliable sequences of several molecular targets of dermatophytes species were used to design a multiplex PCR for the identification of common pathogenic dermatophytes. The isolates and clinical specimens examined in this study included seven standard strains of dermatophytes, 101 isolates of dermatophytes and non-dermatophyte molds/yeasts which had already been identified by sequencing or PCR-restriction fragment length polymorphism (RFLP), and 155 clinical samples from patients suspected of cutaneous mycoses. Results: Species-specific primer pairs for T. rubrum and T. interdigitale/T. mentagrophytes were designed based on the sequence data of the translation elongation factor 1-alpha gene, and the primers for E. floccosum targeted the specific sequence of the internal transcribed spacer region (ITS). The multiplex PCR successfully detected T.rubrum, T. interdigitale/T. mentagrophytes, and E. floccosum strains that were identified by sequencing or PCR-RFLP. However, the primer pairs selected for T. interdigitale/T. mentagrophytes cross-reacted with Trichophyton tonsurans. In testing the PCR system directly for clinical samples, the proportion of positive multiplex PCR was higher than positive culture (68.1% vs. 55.4%, respectively). Conclusion: The multiplex assay could detect three common agents out of several causal agents of dermatophytosis, namely T. rubrum, T. interdigitale, and E. floccosum.Therefore, by adding pan-dermatophyte primers it can be used as a comprehensive detection/identification test.

2015 ◽  
Vol 4 (4) ◽  
Author(s):  
Roberta Mazza ◽  
Francesca Piras ◽  
Daniela Ladu ◽  
Miriam Putzolu ◽  
Simonetta Gianna Consolati ◽  
...  

Listeriosis is a foodborne disease caused by <em>Listeria monocytogenes</em> and is considered as a serious health problem, due to the severity of symptoms and the high mortality rate. Recently, other <em>Listeria</em> species have been associated with disease in human and animals. The aim of this study was to develop a multiplex polymerase chain reaction (PCR) in order to simultaneously detect six Listeria species (<em>L. grayi</em>, <em>L. welshimeri</em>, <em>L. ivanovii</em>, <em>L. monocytogenes</em>, <em>L. seeligeri</em>, <em>L. innocua</em>) in a single reaction. One hundred eighteen <em>Listeria</em> spp. strains, isolated from meat products (sausages) and processing plants (surfaces in contact and not in contact with meat), were included in the study. All the strains were submitted to biochemical identification using the API Listeria system. A multiplex PCR was developed with the aim to identify the six species of <em>Listeria</em>. PCR allowed to uniquely identify strains that had expressed a doubtful profile with API Listeria The results suggest that the multiplex PCR could represent a rapid and sensitive screening test, a reliable method for the detection of all <em>Listeria</em> species, both in contaminated food and in clinical samples, and also a tool that could be used for epidemiological purposes in food-borne outbreaks. A further application could be the development of a PCR that can be directly applied to the pre-enrichment broth.


2021 ◽  
Vol 15 ◽  
Author(s):  
Sara Galeb ◽  
Maysaa El Sayed Zaki ◽  
Raghdaa Shrief ◽  
Rasha Hassan ◽  
Mohamed Anies

Background: Proper identification of the causative organism in pediatric sepsis is crucial for early diagnosis and prevention of septic shock and organ failure. Objectives: The present study aimed to evaluate the multiplex Polymerase Chain Reaction (PCR) to detect Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia from positive blood cultures for these pathogens isolated from children, with hospital-acquired sepsis compared to the conventional biochemical reactions for identification of these organisms. Methods: This study was a cross-sectional study performed on 100 isolates from pediatric blood cultures, including Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia. The study also included 100 isolates of Escherichia coli as a negative control. All isolates were identified by API 20NE and the multiplex PCR, with primers specific to the 3 tested bacteria. Results: Multiplex PCR was positive in 96% of isolates, and 4 isolates had negative results. False positive results were reported with three E. coli strains. Multiplex PCR identified all the isolates of Acinetobacter baumannii, 29 isolates of Pseudomonas aeruginosa, and 27 isolates of Stenotrophomonas maltophilia. Compared to the biochemical identification, the diagnostic value of the multiplex PCR revealed 96.04% sensitivity, 96.9% specificity, 97.00%, positive predictive value, 96.00% negative predictive value, and 96.50% accuracy. Conclusion: The present study highlights the diagnostic value of multiplex PCR to identify Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia from positive blood cultures. Multiplex PCR was sensitive, specific, and accurate. The accuracy differs according to the organisms, with 100% accuracy for Acinetobacter baumannii.


2001 ◽  
Vol 64 (5) ◽  
pp. 664-668 ◽  
Author(s):  
SUDHIR TAMARAPU ◽  
JOHN L. McKILLIP ◽  
MARYANNE DRAKE

A multiplex polymerase chain reaction (PCR) assay was developed for the detection and differentiation of enterotoxigenic Staphylococcus aureus in dairy products. A solvent extraction procedure was successfully modified for extraction of S. aureus DNA from 10 ml of artificially contaminated skim milk or 20 g cheddar cheese. Primers targeting the enterotoxin C gene (entC) and thermostable nuclease gene (nuc) were used in the multiplex PCR. PCR products were confirmed using restriction fragment length polymorphism analysis. DNA was consistently quantified and amplified by uniplex PCR from 10 CFU/ml of S. aureus in skim milk or 10 CFU/20 g cheddar cheese. The sensitivity of the multiplex PCR was 100 CFU/ml of skim milk or 100 CFU/20 g cheddar cheese. The developed methodology allows presumptive identification and differentiation of enterotoxigenic S. aureus in less than 6 h.


2014 ◽  
Vol 38 (1) ◽  
pp. 99-106
Author(s):  
Ihab G. M. AL-Shemmari

The aim of this study was to identify pasteurella multocida and their types by PCR in cattle’s and buffaloesi bagdad from March to August 2012 on 204 animals , including 102 cattle and 102 buffaloes at slaughter houses from Baghdad .Blood samples and nasal swaps were collected , before slaughtering and lung tissues of slaughtered animal , and from 54 clinically suspected cases of pasteurellosis , including 27 bovines ,and 27 buffaloes the samples taken included blood and nasal swabs . Pasteurellamultocida were isolated from 94 animals include 49 cattle 45 buffaloes. The typing of the isolates by multiplex PCR for genotyping Pasteuerllamultocida revealed 93 isolates of type B , 31 from cattle and 62 from buffaloes ,and 81 isolates of type A , 55 from cattle and 26 from buffaloes .


2002 ◽  
Vol 65 (5) ◽  
pp. 780-785 ◽  
Author(s):  
IRENE V. WESLEY ◽  
KAREN M. HARMON ◽  
JAMES S. DICKSON ◽  
ANN RAMOS SCHWARTZ

A multiplex polymerase chain reaction was developed to simultaneously identify Listeria monocytogenes and species of the genus Listeria. Two sets of primers were used, with the first amplifying a 938-bp region of the 16S rRNA gene that is highly conserved in all Listeria species and the second amplifying a 174-bp region of the listeriolysin (hlyA) gene of L. monocytogenes. Thus, isolates of Listeria spp. yield a single 938-bp product, whereas L. monocytogenes isolates yield both the 938-bp product and a 174-bp product. The specificity of the assay was verified with all six Listeria species and 11 serotypes of L. monocytogenes, as well as nonrelated bacteria. The multiplex PCR assay was used to determine the incidence of Listeria spp., especially L. monocytogenes, in mechanically separated turkey samples (n = 150 samples). L. monocytogenes strains were selected by using the University of Vermont two-step enrichment protocol and plating to selective Palcam agar. The multiplex PCR assay was used for verification of presumptive Listeria colonies. Approximately 38% of mechanically separated turkey samples (57 of 150) yielded L. monocytogenes; an additional 18% of these samples (27 of 150) harbored other Listeria spp. Fifty-one percent (29 of 57) of the L. monocytogenes isolates were of serogroup 1, 44% (25 of 57) were of serogroup 4, and 2% (1 of 57) were assigned to serogroups other than 1 and 4.


2014 ◽  
Vol 56 (5) ◽  
pp. 391-395 ◽  
Author(s):  
Herintha Coeto Neitzke-Abreu ◽  
Kárin Rosi Reinhold-Castro ◽  
Mateus Sabaini Venazzi ◽  
Regiane Bertin de Lima Scodro ◽  
Alessandra de Cassia Dias ◽  
...  

Sandflies transmit pathogens of leishmaniasis. The natural infection of sandflies by Leishmania (Viannia) was assessed in municipalities, in the state of Paraná, in Southern Brazil. Sandflies were collected with Falcão and Shannon traps. After dissection in search of flagellates in digestive tubes and identification of the species, female sandflies were submitted to the Multiplex Polymerase Chain Reaction (multiplex PCR) for detection of the fragment of the kDNA of Leishmania (Viannia) and the fragment from the IVS6 cacophony gene region of the phlebotomine insects. The analysis was performed in pools containing seven to 12 guts from females of the same species. A total of 510 female sandflies were analyzed, including nine Migonemyia migonei, 17 Pintomyia fischeri, 216 Nyssomyia neivai, and 268 Nyssomyia whitmani. Although none of the females was found naturally infected by flagellates through dissection, the fragment of DNA from Leishmania (Viannia) was shown by multiplex PCR in one sample of Ny. neivai (0.46%) and three samples of Ny. whitmani (1.12%). It was concluded that Ny. neivai and Ny. whitmani are susceptible to Leishmania infection, and that multiplex PCR can be used in epidemiological studies to detect the natural infection of the sandfly vector, because of its sensitivity, specificity and feasibility.


2000 ◽  
Vol 63 (8) ◽  
pp. 1032-1037 ◽  
Author(s):  
PINA M. FRATAMICO ◽  
LORI K. BAGI ◽  
TIZIANA PEPE

A multiplex polymerase chain reaction (PCR) assay was designed to simplify detection of Escherichia coli O157:H7 and to identify the H serogroup and the type of Shiga toxin produced by this bacterium. Primers for a plasmid-encoded hemolysin gene (hly933), and chromosomal flagella (fliCh7; flagellar structural gene of H7 serogroup), Shiga toxins (stx1, stx2), and attaching and effacing (eaeA) genes were used in a multiplex PCR for coamplification of the corresponding DNA sequences from enterohemorrhagic E. coli (EHEC) O157:H7. Enrichment cultures of ground beef, blue cheese, mussels, alfalfa sprouts, and bovine feces, artificially inoculated with various levels of E. coli O157:H7 strain 933, were subjected to a simple DNA extraction step prior to the PCR, and the resulting amplification products were analyzed by agarose gel electrophoresis. Sensitivity of the assay was ≤1 CFU/g of food or bovine feces (initial inoculum level), and results could be obtained within 24 h. Similar detection levels were obtained with ground beef samples that underwent enrichment culturing immediately after inoculation and samples that were frozen or refrigerated prior to enrichment. The multiplex PCR facilitates detection of E. coli O157:H7 and can reduce the time required for confirmation of isolates by up to 3 to 4 days.


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