Improved specificity ofTrypanosoma cruziidentification by polymerase chain reaction using an oligonucleotide derived from the amino-terminal sequence of a Tc24 protein

Parasitology ◽  
1995 ◽  
Vol 111 (5) ◽  
pp. 581-590 ◽  
Author(s):  
A. Taibi ◽  
A. Guevara-Espinoza ◽  
R. Schöneck ◽  
B. Yahiaoui ◽  
A. Ouaissi
Keyword(s):  
Polymerase Chain Reaction ◽  
Diagnostic Value ◽  
Terminal Sequence ◽  
Chain Reaction ◽  
Blood Samples ◽  
Specific Diagnosis ◽  
Amino Terminal ◽  
Polymerase Chain ◽  
Amino Terminal Domain ◽  
Amino Terminal Sequence

SUMMARYIn the present study, the diagnostic value ofTrypanosoma cruzirecombinant protein (Tc24) was examined. Although antibodies against Tc24 were detected during natural and experimentalT. cruziinfections, specificity studies revealed that sera fromT. rangeli-infected mice also recognized to some extent Tc24 protein. In addition, sera from Tc24-immunized mice reacted against a 21 kDa polypeptide inT. rangeliextracts. Detailed analysis of the antibody response against 20—40 peptide localized in the Tc24 amino-terminal domain suggests that this sequence is not expressed byT. rangeli21 kDa antigen. Therefore, the PCR reaction using oligonucleotides corresponding to a 20–26 peptide clearly demonstrated the specificity of the oligoprobes forT. cruziidentification. Positive signals were also found when using blood samples fromT. cruzi-infected mice. Taken together, these results suggest that the PCR-based 20–26 assay may be useful in the specific diagnosis of Chagas' disease.

Comparison of Droplet Digital Polymerase Chain Reaction (ddPCR) and Real-Time Quantitative Polymerase Chain Reaction (qPCR) in Detecting Neonatal Invasive Fungal Infections

2021 ◽  
Vol 11 (3) ◽  
pp. 373-379
Author(s):  
Huitao Li ◽  
Xueyu Chen ◽  
Xiaomei Qiu ◽  
Weimin Huang ◽  
Chuanzhong Yang
Keyword(s):  
Polymerase Chain Reaction ◽  
Limit Of Detection ◽  
Quantitative Polymerase Chain Reaction ◽  
Diagnostic Methods ◽  
Chain Reaction ◽  
Fungal Isolation ◽  
Blood Samples ◽  
Fungal Strains ◽  
Polymerase Chain ◽  
Digital Polymerase Chain Reaction

Invasive fungal infection (IFI) is the leading cause of death in neonatal patients, yet the diagnosis of IFI remains a major challenge. At present, most IFI laboratory diagnostic methods are based on classical, but limited, methods such as fungal isolation and culture and histopathological examination. Recently, quantitative polymerase chain reaction (qPCR) and droplet digital polymerase chain reaction (ddPCR) technology have been adopted to quantify nucleic-acid identification. In this study, we established qPCR and ddPCR assays for IFI diagnosis and quantification. qPCR and ddPCR were carried out using identical primers and probe for the amplification of 18S rRNA. Assay results for three fungal strains were positive, whereas ten non-fungal strains had negative results, indicating 100% specificity for both ddPCR and qPCR methods. Genomic DNA of Candida albicans was tested after a serial dilution to compare the sensitivity of the two PCR methods. The limit of detection of ddPCR was 3.2 copies/L, which was a ten-fold increase compared with that of the qPCR method (32 copies/L). Blood samples from 127 patients with high-risk factors and clinical symptoms for IFI were collected from a NICU in Shenzhen, China, and analyzed using qPCR and ddPCR. Thirty-four blood samples from neonates had a proven or probable diagnosis of IFI, and 25 of these were positive by qPCR, whereas 30 were positive by ddPCR. Among the 93 blood samples from neonates who had a possible IFI or no IFI, 24 were positive using qPCR, and 7 were positive using ddPCR. In conclusion, ddPCR is a rapid and accurate pan-fungal detection method and provides a promising prospect for IFI clinical screening.

Diagnostic Value of Multiplex Polymerase Chain Reaction in Detection of Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia from Sepsis in Pediatrics

2021 ◽  
Vol 15 ◽  
Author(s):  
Sara Galeb ◽  
Maysaa El Sayed Zaki ◽  
Raghdaa Shrief ◽  
Rasha Hassan ◽  
Mohamed Anies
Keyword(s):  
Polymerase Chain Reaction ◽  
Pseudomonas Aeruginosa ◽  
Acinetobacter Baumannii ◽  
Multiplex Pcr ◽  
Stenotrophomonas Maltophilia ◽  
Multiplex Polymerase Chain Reaction ◽  
Diagnostic Value ◽  
Blood Cultures ◽  
Chain Reaction ◽  
Polymerase Chain

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.

scholarly journals Polymerase Chain Reaction and blood culture for diagnosis of canine sepsis

2018 ◽  
Vol 48 (6) ◽  
Author(s):  
Marcelo Marques da Silveira ◽  
Stéfhano Luis Cândido ◽  
Karin Rinaldi dos Santos ◽  
Maerle Oliveira Maia ◽  
Roberto Lopes de Souza ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Blood Culture ◽  
Diagnostic Value ◽  
Turnaround Time ◽  
Diagnostic Techniques ◽  
Pcr Analysis ◽  
Chain Reaction ◽  
Suspected Sepsis ◽  
Fungal Dna ◽  
Polymerase Chain

ABSTRACT: Sepsis is characterized by the presence of organ dysfunction secondary to the dysregulated systemic inflammatory response associated with an infection, and has high mortality rates. Traditional diagnostic techniques based on non-microbiological isolation are time-consuming and may delay treatment. Thus, this study aimed to compare bacterial and fungal broad-range polymerase chain reaction (PCR) and blood culture for diagnosis of sepsis in dogs. Blood samples from 88 dogs with suspected sepsis were analyzed by blood culture, and PCR to detect bacterial and fungal DNA. On blood culture, 20 (22.7%) samples tested positive for bacterial isolates; however, none tested positive for fungi. Through PCR analysis, bacterial DNA was detected in 46 (52.3%) animals, whereas fungal DNA was present in one (1.1%) sample. Our results showed that PCR-based testing has important diagnostic value for canine blood infections because it has a shorter turnaround time and higher sensitivity than traditional blood culture.

scholarly journals The diagnostic value of polymerase chain reaction in erythema induratum of Bazin

1997 ◽  
Vol 137 (6) ◽  
pp. 1011-1012 ◽  
Author(s):  
D. Seckin ◽  
N. Hizel ◽  
B. Demirhan ◽  
C. Tuncay
Keyword(s):  
Polymerase Chain Reaction ◽  
Diagnostic Value ◽  
Chain Reaction ◽  
Polymerase Chain

scholarly journals Molecular detection and occurrence of equine theileriosis in Arabian horses in Al-Najaf province/Iraq

2020 ◽  
Vol 57 (3) ◽  
pp. e166996
Author(s):  
Hayder Mohammad Al-Rammahi ◽  
Abdulameer Abed Hatem ◽  
Asaad Chasib Al-Atabi
Keyword(s):  
Polymerase Chain Reaction ◽  
Dna Extraction ◽  
Molecular Detection ◽  
Molecular Technique ◽  
Chain Reaction ◽  
Blood Samples ◽  
Equine Piroplasmosis ◽  
Polymerase Chain

This study was designed to detect equine piroplasmosis using the molecular technique in Al-Najaf province during the season that showed an increment in tick activities. Blood samples were collected from 110 horses with more than two signs of piroplasmosis. After DNA extraction, the product was examined by a polymerase chain reaction to amplify 18SrRNA. The results showed that the overall percentage of equine theileriosis was 38.18%. According to gender, the percentage of infection was 43.48% and 29.27% in females and males, respectively. Significant variations appeared between infected horses according to age, and the percentage of infection was 50% and 35.22% in less than 2 years and more than 2 years age, respectively. Moreover, the percentage of infection was 62.5% and 19.35% in animals with and without acariasis, respectively. Significant variations were also seen in equine theileriosis according to geographical areas, and the higher percentage was reported in Hera district (60.87%), while the lowest percentage was in the center of Al-Najaf (21.43%). This difference may be due to different distribution of vector of disease (tick), which may be the availability of the suitable weather that helped in the multiplication of the intermediate vectors. In conclusion, this study proved the variations in the occurrences of equine piroplasmosis according to gender, age, and geographical areas.

scholarly journals Molecular identification by multiplex polymerase chain reaction of Pasteurella multocida in cattle and buffaloes in Baghdad

2014 ◽  
Vol 38 (1) ◽  
pp. 99-106
Author(s):  
Ihab G. M. AL-Shemmari
Keyword(s):  
Polymerase Chain Reaction ◽  
Multiplex Pcr ◽  
Multiplex Polymerase Chain Reaction ◽  
Pasteurella Multocida ◽  
Type B ◽  
Chain Reaction ◽  
Blood Samples ◽  
Nasal Swabs ◽  
Polymerase Chain ◽  
B 31

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 .

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