scholarly journals Development of Conventional Multiplex PCR: A Rapid Technique for Simultaneous Detection of Soil-Transmitted Helminths

Pathogens ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 152 ◽  
Author(s):  
Vivornpun Sanprasert ◽  
Ruthairat Kerdkaew ◽  
Siriporn Srirungruang ◽  
Sarit Charuchaibovorn ◽  
Kobpat Phadungsaksawasdi ◽  
...  

Soil-transmitted helminths (STHs) are the most common intestinal parasites infecting humans worldwide. STH infections are a major cause of morbidity and disability. Accurate diagnostic tools are pivotal for assessing the exact prevalence of parasitic infections. Microscopic examination and culture techniques have been used to observe the presence of eggs or larvae of parasites in stool samples, but they are time-consuming and have low sensitivity. Therefore, accurate, simple, and inexpensive diagnostic techniques are still required for simultaneous detection of STH infections. Although molecular-based techniques, such as real-time PCR and multiplex real-time PCR, have been developed, they are not suitable for routine diagnosis due to the requirement for expensive reagents and instruments. In this study, we established a conventional multiplex PCR for simultaneous rapid detection of Ascaris lumbricoides, Necator americanus, and Strongyloides stercoralis in stool samples. Our results show that the multiplex PCR could detect the DNA of STHs at a very low target gene concentrations (lower than 1 pg) with no cross-amplification. Multiplex PCR had five times higher sensitivity than the formalin–ethyl acetate concentration technique (FECT) in the detection of multiple infections, and two times higher for detection of S. stercoralis. However, multiplex PCR was comparable to FECT in the detection of A. lumbricoides and N. americanus. In conclusion, this method could be used as an alternative method for the detection of STHs, especially for S. stercoralis.

2020 ◽  
Vol 9 (1) ◽  
pp. 54
Author(s):  
Salem Belkessa ◽  
Daniel Thomas-Lopez ◽  
Karim Houali ◽  
Farida Ghalmi ◽  
Christen Rune Stensvold

The molecular epidemiology of giardiasis in Africa remains unclear. A study was carried out across four hospitals in Algeria. A total of 119 fecal samples from 55 children, 37 adults, and 27 individuals of undetermined age, all scored positive for intestinal parasites by microscopy, and were screened by real-time PCR for Giardia. Molecular characterization of Giardia was performed by assemblage-specific PCR and PCR targeting the triose phosphate isomerase gene (tpi). Of the 119 samples, 80 (67%) were Giardia-positive by real-time PCR. For 48 moderately-highly real-time PCR-positive samples, tpi genotyping assigned 22 samples to Assemblage A and 26 to Assemblage B. Contrary to Assemblage A, Assemblage B exhibited substantial genetic diversity and allelic heterozygosity. Assemblage-specific PCR proved to be specific for discriminating Assemblage A or B but not as sensitive as tpi genotyping. We confirmed that real-time PCR is more sensitive than microscopy for detecting Giardia in stool samples and that robust amplification and sequencing of the tpi gene is feasible when moderate-to-strongly real-time PCR-positive samples are used. This study is one of the few performed in Africa providing genotyping data on Giardia infections in humans. Both assemblages A and B were commonly seen and not associated with specific sociodemographic data.


2011 ◽  
Vol 60 (4) ◽  
pp. 459-466 ◽  
Author(s):  
Spencer D. Polley ◽  
Samuel Boadi ◽  
Julie Watson ◽  
Alan Curry ◽  
Peter L. Chiodini

Diagnosis of microsporidial infections is routinely performed by light microscopy, with unequivocal non-molecular species identification achievable only through electron microscopy. This study describes a single SYBR Green real-time PCR assay for the simultaneous detection and species identification of such infections. This assay was highly sensitive, routinely detecting infections containing 400 parasites (g stool sample)−1, whilst species identification was achieved by differential melt curves on a Corbett Life Science Rotor-Gene 3000. A modification of the QIAamp DNA tissue extraction protocol allowed the semi-automated extraction of DNA from stools for the routine diagnosis of microsporidial infection by real-time PCR. Of 168 stool samples routinely analysed for microsporidian spores, only five were positive by microscopy. By comparison, 17 were positive for microsporidial DNA by real-time analysis, comprising 14 Enterocytozoon bieneusi, one Encephalitozoon cuniculi and two separate Pleistophora species infections.


2021 ◽  
Author(s):  
Marina Papaiakovou ◽  
Nils Pilotte ◽  
Julia Dunn ◽  
David TJ Littlewood ◽  
Rubén O Cimino ◽  
...  

AbstractDue to its simplicity and cost-effectiveness, microscopy has seen extensive field-use as the diagnostic standard for the detection of soil-transmitted helminths (STH) in stool samples. However, the sensitivity of microscopy-based detection is inadequate in reduced-transmission settings where worm burden is oftentimes low. Equally problematic, eggs of closely related species oftentimes have indistinguishable morphologies, leading to species misidentification. In light of these shortcomings, the purpose of this study was to demonstrate multi-parallel quantitative real-time PCR (qPCR) as the new “gold standard” for STH detection. Accordingly, stool samples from non-endemic participants were spiked with limited numbers of eggs or larvae (1 to 40) of five different species of STH. DNA extracts were tested using two unique multi-parallel real-time PCR-based diagnostic methods. These methods employed different target sequences (ribosomal internal transcribed spacer, or highly repetitive non-coding regions), to evaluate the detection of DNA from as little as one egg per sample. There was a statistically significant kendall correlation between egg/larvae counts and qPCR from both methods for Trichuris trichiura (0.86 and 0.872 for NHM and Baylor assays) and a strong correlation (0.602 and 0.631 for NHM and Baylor assays, respectively) for Ascaris lumbricoides. Less strong but still significant was the Kendall Tau-b value for A. duodenale (0.408 for both) and for S. stercoralis (0.483 and 0.653, respectively). In addition, using field stool samples from rural Argentina both assays had fair to moderate kappa agreement (0.329-0.454), except for Strongyloides stercoralis (0.121) that both assays had slight agreement. In spite of the small cohort of samples, both qPCR assays, targeting of two independent genomic regions, provided reproducible results and we believe that, low cost multi-parallel quantitative real-time PCR-based diagnostics should supplant microscopy as the new gold standard for stool-based detection of soil transmitted helminths in public-health and community settings.


2013 ◽  
Vol 62 (9) ◽  
pp. 1428-1434 ◽  
Author(s):  
Elina G. Dobreva ◽  
Ivan N. Ivanov ◽  
Rossitza S. Vathcheva-Dobrevska ◽  
Katucha I. Ivanova ◽  
Galina D. Asseva ◽  
...  

The increasing incidence of Clostridium difficile infection (CDI) in Bulgaria has indicated the need to implement better surveillance approaches. The aim of the present work was to improve the current surveillance of CDI in Bulgaria by introducing innovative methods for identification and typing. One hundred and twenty stool samples obtained from 108 patients were studied over 4 years from which 32 C. difficile isolates were obtained. An innovative duplex EvaGreen real-time PCR assay based on simultaneous detection of the gluD and tcdB genes was developed for rapid C. difficile identification. Four toxigenic profiles were distinguished by PCR: A+B+CDT− (53.1 %, 17/32), A−B+CDT− (28.1 %, 9/32), A+B+CDT+ (9.4 %, 3/32) and A−B−CDT− (9.4 %, 3/32). PCR ribotyping and multilocus variable number of tandem repeat analysis (MLVA7) were used for molecular characterization of the isolates. In total, nine distinct ribotypes were confirmed and the most prevalent for Bulgarian hospitals was 017 followed by 014/020, together accounting for 44 % of all isolates. Eighteen per cent of the isolates (6/32) did not match any of the 25 reference ribotypes available in this study. Twenty-four MLVA7 genotypes were detected among the clinical C. difficile isolates, distributed as follows: five for 017 ribotype, two for 014/020, 001, 002, 012 and 046 each, and one each for ribotypes 023, 070 and 078. The correlation between the typing methods was significant and allowed the identification of several clonal complexes. These results suggest that most C. difficile cases in the eight Bulgarian hospitals studied were associated with isolates belonging to the outbreak ribotypes 017 and 014/20, which are widely distributed in Europe. The real-time PCR protocol for simultaneous detection of gluD and tcdB proved to be very effective and improved C. difficile identification and confirmation of clinical C. difficile isolates.


COVID ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 5-17
Author(s):  
Tingting Liu ◽  
Lin Kang ◽  
Yanwei Li ◽  
Jing Huang ◽  
Zishuo Guo ◽  
...  

Human coronaviruses (HCoVs) are associated with a range of respiratory symptoms. The discovery of severe acute respiratory syndrome (SARS)-CoV, Middle East respiratory syndrome, and SARS-CoV-2 pose a significant threat to human health. In this study, we developed a method (HCoV-MS) that combines multiplex PCR with matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), to detect and differentiate seven HCoVs simultaneously. The HCoV-MS method had high specificity and sensitivity, with a 1–5 copies/reaction detection limit. To validate the HCoV-MS method, we tested 163 clinical samples, and the results showed good concordance with real-time PCR. Additionally, the detection sensitivity of HCoV-MS and real-time PCR was comparable. The HCoV-MS method is a sensitive assay, requiring only 1 μL of a sample. Moreover, it is a high-throughput method, allowing 384 samples to be processed simultaneously in 30 min. We propose that this method be used to complement real-time PCR for large-scale screening studies.


2019 ◽  
Vol 13 (1) ◽  
pp. 4-11
Author(s):  
Sharmili Paul ◽  
Sharmeen Ahmed ◽  
Shaheda Anwar ◽  
Lima Rahman ◽  
Zubair Shams

The prevalence of STIs related cervicitis in Bangladesh among female sex workers (FSWs) is quite high and among them young (≤ 24 years) FSWs are more sufferers. The aim of this study was to detect infectious agents of cervicitis including Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma urealyticum and Ureaplasma parvum in SWs of aged 10-24 years from endocervical swabs by multiplex real time PCR. A cross sectional study was done in collaboration with department of Microbiology, BSMMU, Dhaka and Save the Children, Bangladesh between March to December 2017 among sex workers enlisted to receive HIV prevention services at different drop in centers (DICs) in Dhaka.Total 105 SWs of aged between 10-24 years and clinically suspected as cervicitis, were enrolled for the study. Endo-cervical swabs were collected during examination and tested in dept of Microbiology, BSMMU by multiplex PCR and other tests for aforementioned pathogens. Data were collected by face to face interview using semi-structured questionnaire and clinical examinations were done using Casco’s vaginal speculum. Among the study population, 87 (82.9%) were between 20-24 years of age. On examination, out of 105, 67 (63.8%) patients had no cervical discharge, only 8 (7.6%) had muco-purulent discharge. Out of total, 95 (90.5%) patients were mPCR positive for at least one pathogen and only 3 (2.9 %) N. gonorrhoeae isolated by culture, 8(7.6%) cases of C. trachomatis were detected by DFA and 8 (7.6%) cases of T. vaginalis were detected by wet film. Among the mPCR positive (95) cases, 63(66.3%) patients had mixed infections and among them, M. hominis was the highest (76.2%) followed by U. urealyticum (49.2%). In the patients having ‘no’ (67) cervical discharge, 32 (48%) had M. homini sinfection followed by U. parvum (40%). Majority of FSWs had mixed infection and M.hominis was the highest. A high number of patients hadno cervical discharge though it is one of the diagnostic criteria for cervicitis in current syndromic management. In comparison to other available diagnostic tests, organisms were detected efficiently by multiplex PCR and could be advised routinely in such cases of mixed infection. Bangladesh J Med Microbiol 2019; 13 (1): 4-11


2019 ◽  
Vol 57 (4) ◽  
Author(s):  
Aubree J. Kelly ◽  
Sandor E. Karpathy ◽  
Christopher A. Gulvik ◽  
Melissa L. Ivey ◽  
Anne M. Whitney ◽  
...  

ABSTRACTNosocomial infections ofElizabethkingiaspecies can have fatal outcomes if not identified and treated properly. The current diagnostic tools available require culture and isolation, which can extend the reporting time and delay treatment. Using comparative genomics, we developed an efficient multiplex real-time PCR for the simultaneous detection of all known species ofElizabethkingia, as well as differentiating the two most commonly reported species,Elizabethkingia anophelisandElizabethkingia meningoseptica.


2021 ◽  
Vol 15 (9) ◽  
pp. e0009782
Author(s):  
Jason L. Cantera ◽  
Heather N. White ◽  
Mattahew S. Forrest ◽  
Oliver W. Stringer ◽  
Vicente Y. Belizario ◽  
...  

Background Soil-transmitted helminths (STHs) are parasitic nematodes that inhabit the human intestine. They affect more than 1.5 billion people worldwide, causing physical and cognitive impairment in children. The global strategy to control STH infection includes periodic mass drug administration (MDA) based on the results of diagnostic testing among populations at risk, but the current microscopy method for detecting infection has diminished sensitivity as the intensity of infection decreases. Thus, improved diagnostic tools are needed to support decision-making for STH control programs. Methodology We developed a nucleic acid amplification test based on recombinase polymerase amplification (RPA) technology to detect STH in stool. We designed primers and probes for each of the four STH species, optimized the assay, and then verified its performance using clinical stool samples. Principal findings Each RPA assay was as sensitive as a real-time polymerase chain reaction (PCR) assay in detecting copies of cloned target DNA sequences. The RPA assay amplified the target in DNA extracted from human stool samples that were positive for STH based on the Kato-Katz method, with no cross-reactivity of the non-target genomic DNA. When tested with clinical stool samples from patients with infections of light, moderate, and heavy intensity, the RPA assays demonstrated performance comparable to that of real-time PCR, with better results than Kato-Katz. This new rapid, sensitive and field-deployable method for detecting STH infections can help STH control programs achieve their goals. Conclusions Semi-quantitation of target by RPA assay is possible and is comparable to real-time PCR. With proper instrumentation, RPA assays can provide robust, semi-quantification of STH DNA targets as an alternative field-deployable indicator to counts of helminth eggs for assessing infection intensity.


Sign in / Sign up

Export Citation Format

Share Document