Comparison of macroscopy, histopathology and PCR for diagnosing Eimeria spp. in broiler chickens

ABSTRACT: Coccidiosis is a disease of great importance in industrial poultry. The correct diagnosis directs the poultry industry to its best treatment and control. Thus, a survey of Eimeria spp. was carried out in intestines of 64 broiler flocks, with an average age of 29 days. Eight broilers from each flock were randomly removed from the slaughter line, in a total of 512 samples. Macroscopic and histopathological lesions in the intestine were classified into Scores 0 to 4. Polymerase chain reaction (PCR) was used to research the oocysts from the seven species of Eimeria spp. in the intestinal content. The macroscopic evaluations showed that 59.4% (38/64) of the flocks were positive for E. acervulina, 32.8% (21/64) for E. maxima, 29.7% (19/64) for E. tenella, and 34.4% (22/64) for E. brunetti. The histopathological evaluation showed that 87.5% (56/64) of the flocks had at least one broiler with parasitic structures compatible with Eimeria spp. in the duodenum, 70.3% (45/64) in the jejunum, 18.8% (12/64) in the ileum, 46.9% (30/64) in the cecum, and 4.7% (3/64) in the colon. In PCR, 21.9% (14/64) of the flocks were positive for E. acervulina, 12.5% (8/64) for E. maxima, 3.1% (2/64) for E. mitis, and 32.8% (21/64) for E. tenella. The Kappa Cohen test between macroscopy, histopathology, and PCR demonstrated concordance ranging from weak to moderate with the exception of histopathology and PCR of the cecum, which was strong. In the comparison between macroscopy and histopathology, there were significative differences between Scores 0 and 1 (apart from the cecum). For Score 3, there were significative differences in duodenum, jejunum and cecum (p<0.05). In conclusion, the macroscopic diagnosis and PCR can generate false-negative results, and the histopathological exam proved to be effective, making it essential to associate different techniques for the correct diagnosis of Eimeria spp. in broiler chickens.

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False-negative results by polymerase chain reaction due to contamination by glove powder

Transfusion ◽

10.1046/j.1537-2995.1992.32192116439.x ◽

1992 ◽

Vol 32 (1) ◽

pp. 83-85 ◽

Cited By ~ 23

Author(s):

JG Lomas ◽

FJ Sunzeri ◽

MP Busch

Keyword(s):

Polymerase Chain Reaction ◽

False Negative ◽

Chain Reaction ◽

Negative Results ◽

False Negative Results ◽

Polymerase Chain

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The Use of a Mimic to Detect Polymerase Chain Reaction– Inhibitory Factors in Feces Examined for the Presence of Lawsonia Intracellularis

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063870301500308 ◽

2003 ◽

Vol 15 (3) ◽

pp. 268-273 ◽

Cited By ~ 19

Author(s):

Magdalena Jacobson ◽

Stina Englund ◽

András Ballagi-Pordány

Keyword(s):

Polymerase Chain Reaction ◽

False Negative ◽

Clinical Samples ◽

Lawsonia Intracellularis ◽

Chain Reaction ◽

Fecal Samples ◽

Wild Boars ◽

Negative Results ◽

False Negative Results ◽

Polymerase Chain

Lawsonia intracellularis is an intracellular organism that causes proliferative enteritis in pigs. This bacterium is difficult to culture, and antemortem demonstration of the microbe is therefore often performed on fecal samples by polymerase chain reaction (PCR). Polymerase chain reaction is sensitive and specific, but inhibitory factors in feces might cause false-negative results. This article describes the construction and use of an internal standard, a mimic. The mimic is amplified by the same primers as those used for L. intracellularis DNA and thus could indicate false-negative results in clinical samples. The amplicon was clearly visible when as few as 10 mimic molecules were added per amplification reaction and when no inhibitors were present. When fecal samples were spiked with the mimic, the detection limit was 102 molecules per PCR. Sixty clinical samples, 20 from wild boars, 20 from growing pigs with diarrhea, and 20 from pigs without diarrhea, were prepared by a boiling procedure and subjected to PCR together with 103 mimic molecules. Nine samples were positive, of which 7 originated from pigs with diarrhea and 2 from pigs without diarrhea. In 14 samples from wild boars, in 8 samples from pigs without diarrhea, and in 3 samples from pigs with diarrhea, neither the mimic nor the target DNA was visible. This indicated the presence of inhibitors in these samples. It is concluded that the mimic can be used as an internal control in the diagnosis of L. intracellularis to indicate inhibition of PCR.

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Reducing False Negative PCR Test for COVID-19

International Journal of MCH and AIDS (IJMA) ◽

10.21106/ijma.421 ◽

2020 ◽

Vol 9 (3) ◽

pp. 408-410

Author(s):

Fatemeh Bahreini ◽

Rezvan Najafi ◽

Razieh Amini ◽

Salman Khazaei ◽

Saeid Bashirian

Keyword(s):

Polymerase Chain Reaction ◽

Real Time ◽

False Negative ◽

Rt Pcr ◽

Chain Reaction ◽

Creative Commons ◽

Negative Results ◽

False Negative Results ◽

Polymerase Chain ◽

Pcr Test

As the SARS-CoV-2 (COVID-19) pandemic spreads rapidly, there is need for a diagnostic test with high accuracy to detect infected individuals especially those without symptoms. Real-time polymerase chain reaction (RT-PCR) is a common molecular test for diagnosing SARS-CoV-2. If some factors are not taken into consideration when performing this test, it can have a relatively large number of false negative results. In this article, we discuss important considerations that could lead to false negative test reduction. Key words: • SARS-CoV-2 • COVID-19 • Real time polymerase chain reaction • RT-PCR test • Diagnosis • False negatives • Genetics • Emerging disease Copyright © 2020 Bahreini et al. Published by Global Health and Education Projects, Inc. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0)which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in this journal, is properly cited.

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False-Negative Results of Real-Time Reverse-Transcriptase Polymerase Chain Reaction for Severe Acute Respiratory Syndrome Coronavirus 2: Role of Deep-Learning-Based CT Diagnosis and Insights from Two Cases

Korean Journal of Radiology ◽

10.3348/kjr.2020.0146 ◽

2020 ◽

Vol 21 (4) ◽

pp. 505 ◽

Cited By ~ 135

Author(s):

Dasheng Li ◽

Dawei Wang ◽

Jianping Dong ◽

Nana Wang ◽

He Huang ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Deep Learning ◽

Severe Acute Respiratory Syndrome ◽

False Negative ◽

Ct Diagnosis ◽

Chain Reaction ◽

Negative Results ◽

False Negative Results ◽

Polymerase Chain

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Development of a Polymerase Chain Reaction Assay for Detection of Burkholderia mallei, a Potent Biological Warfare Agent

Defence Science Journal ◽

10.14429/dsj.66.10698 ◽

2016 ◽

Vol 66 (5) ◽

pp. 458 ◽

Cited By ~ 2

Author(s):

Vijai Pal ◽

Sandeep Singh ◽

Arvind Kumar Tiwari ◽

Y.K. Jaiswal ◽

G.P. Rai

Keyword(s):

Polymerase Chain Reaction ◽

Tap Water ◽

False Negative ◽

Burkholderia Mallei ◽

Chain Reaction ◽

Pcr Assay ◽

Negative Results ◽

False Negative Results ◽

Polymerase Chain ◽

Rapid Tool

Burkholderia mallei is the etiological agent of glanders, primarily a disease of equines. B. mallei is closely related to B. pseudomallei, the causative agent of melioidosis. Therefore, detection of B. mallei and its differentiation from B. pseudomallei, has always been troublesome. In present investigation, a B. mallei specific DNA sequence was identified by performing BLASTn search using ~3000 ORFs of B. mallei NCTC 10229. A polymerase chain reaction (PCR) assay with internal amplification control (IAC) was developed for detection of B. mallei and its differentiation from B. pseudomallei. The PCR assay could amplify a specific 224-bp fragment from all the six B. mallei strains used in the study, whereas other closely related organisms were tested negative. The detection limit of the assay was found to be 10 pg of purified DNA of B. mallei. Incorporation of IAC in the assay makes the results reliable as false negative results which may arise due to presence of PCR inhibitors, can be avoided. For validation, the assay was tested on tap water, Bengal gram and grass artificially spiked with B. mallei. The developed assay can be used as a simple and rapid tool for detection of B. mallei.

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A Multiplex Real-Time Polymerase Chain Reaction (TaqMan) Assay for the Simultaneous Detection of Meloidogyne chitwoodi and M. fallax

Phytopathology ◽

10.1094/phyto-96-1255 ◽

2006 ◽

Vol 96 (11) ◽

pp. 1255-1262 ◽

Cited By ~ 32

Author(s):

C. Zijlstra ◽

R. A. Van Hoof

Keyword(s):

Polymerase Chain Reaction ◽

Real Time ◽

Real Time Pcr ◽

False Negative ◽

Simultaneous Detection ◽

Chain Reaction ◽

Meloidogyne Chitwoodi ◽

Negative Results ◽

False Negative Results ◽

Polymerase Chain

This study describes a multiplex real-time polymerase chain reaction (PCR) approach for the simultaneous detection of Meloidogyne chitwoodi and M. fallax in a single assay. The approach uses three fluorogenic minor groove binding (MGB) TaqMan probes: one FAM-labeled to detect M. chitwoodi, one VIC-labeled to detect M. fallax, and one NED-labeled to detect the internal amplification control (IAC) to monitor false negative results. One common primer set is used for the amplification of part of the internal transcribed spacer (ITS) region of M. chitwoodi and M. fallax and one primer set for the amplification of the IAC. The test enabled detection of M. chitwoodi and/or M. fallax in DNA samples extracted from batches of juveniles, from single juveniles, and from infected plant material. Compared with current assays to detect M. chitwoodi and M. fallax, the multiplex real-time PCR offers the following advantages: it is faster because the test can simultaneously detect both quarantine species without the need for post-PCR processing; and it is at least 10 times more sensitive than a comparable regular PCR also targeting the ITS sequence. Inclusion of the IAC facilitates the interpretation of the FAM and VIC cycle threshold (Ct) values and can prevent the scoring of false negative results when FAM, VIC, and NED Ct values are high. The test allows precise quantification when only one of the two species is present in the sample. However, experiments with mixtures of genomic DNA of M. chitwoodi and M. fallax revealed that the ability of the multiplex real-time PCR assay to detect small quantities of DNA of one species is reduced when large quantities of DNA of the other species are present.

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False-negative results in polymerase chain reaction–based prenatal diagnosis from maternal blood

American Journal of Obstetrics and Gynecology ◽

10.1016/s0002-9378(97)70231-x ◽

1997 ◽

Vol 177 (2) ◽

pp. 482

Keyword(s):

Polymerase Chain Reaction ◽

Prenatal Diagnosis ◽

False Negative ◽

Maternal Blood ◽

Chain Reaction ◽

Negative Results ◽

False Negative Results ◽

Polymerase Chain

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False-negative Chlamydia polymerase chain reaction result caused by a cryptic plasmid-deficient Chlamydia trachomatis strain in Australia

Sexual Health ◽

10.1071/sh18205 ◽

2019 ◽

Vol 16 (4) ◽

pp. 394 ◽

Cited By ~ 2

Author(s):

Emma L. Sweeney ◽

Cheryl Bletchly ◽

Rita Gupta ◽

David M. Whiley

Keyword(s):

Polymerase Chain Reaction ◽

Chlamydia Trachomatis ◽

False Negative ◽

Cryptic Plasmid ◽

Chain Reaction ◽

Negative Results ◽

False Negative Results ◽

Polymerase Chain ◽

Primer Sets ◽

Pcr Targeting

Background The 7.5-kb chlamydial cryptic plasmid remains a widely used sequence target for Chlamydia trachomatis nucleic acid amplification tests, but sequence variation in this plasmid, particularly a previously reported 377-bp deletion, can cause false-negative results. Here we report the presence in Australia of a C. trachomatis strain lacking the cryptic plasmid. Methods: A rectal swab from a male in his 50s provided a positive result for C. trachomatis using the Roche Cobas 4800 test, but a negative result in our confirmatory in-house polymerase chain reaction (PCR) method targeting the chlamydial cryptic plasmid. This result was unexpected given our in-house PCR assay targeted a region of sequence outside the recognised 377-bp deletion. To further investigate this discrepancy, the sample was retested using a second in-house PCR targeting a chromosomal (ompA) gene as well as six primer sets flanking various regions of the cryptic plasmid. Results: The sample provided positive results in the second in-house method, confirming the presence of C. trachomatis DNA. All other primer sets targeting the cryptic plasmid failed to amplify, indicating a lack of the chlamydial cryptic plasmid in this sample. Conclusions: The recognition of a plasmid-deficient strain of C. trachomatis within Australia highlights further limitations of using the chlamydial cryptic plasmid for C. trachomatis diagnostics and re-emphasises the benefits of using multitarget assays to avoid false-negative results.

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