scholarly journals The Role of Molecular Tests in the Diagnosis of Disseminated Histoplasmosis

2019 ◽  
Vol 6 (1) ◽  
pp. 1 ◽  
Author(s):  
Izadora Clezar da Silva Vasconcellos ◽  
Daiane Flores Dalla Lana ◽  
Alessandro C. Pasqualotto
Keyword(s):  
Severe Infection ◽  
Diagnostic Techniques ◽  
Antigen Detection ◽  
Diagnostic Methods ◽  
Clinical Samples ◽  
Molecular Tests ◽  
Disseminated Histoplasmosis ◽  
Satisfactory Performance ◽  
Polymerase Chain

Histoplasmosis is an emerging fungal disease, with global distribution. The disseminated form of the disease is a more severe infection, generally associated with AIDS. Classic diagnostic methods for histoplasmosis consist of microscopy, culture, and histopathology. More recently, the importance of Histoplasma antigen detection has dominated the literature on histoplasmosis diagnosis, but the relevance of molecular assays has not been as much studied. Here we describe the results of a systematic literature review focusing on studies that mainly compared immunological techniques (Histoplasma urine antigen detection) with molecular tests for the diagnosis of histoplasmosis. In addition to the review of comparative studies using such diagnostic techniques, the literature on polymerase chain reaction (PCR) tests in patients with disseminated histoplasmosis is also summarized. Two studies reported the comparison between immunological and molecular methods applied simultaneously for the diagnosis of disseminated histoplasmosis. PCR demonstrates a satisfactory performance assisting in the detection of Histoplasma spp. DNA in clinical samples.

Studies on Diagnosis of Bovine Brucellosis by Immunocyto-chemistry and Immunohistochemistry

2021 ◽  
Author(s):  
K.S. Lakshmikanth ◽  
N.S. Sharma ◽  
D. Pathak ◽  
Paviter Kaur
Keyword(s):  
Biochemical Analysis ◽  
Placental Tissue ◽  
Diagnostic Techniques ◽  
Clinical Samples ◽  
Bovine Brucellosis ◽  
Reproductive Disorders ◽  
Chain Reaction ◽  
Tissue Samples ◽  
Polymerase Chain ◽  
Positive Results

Background: Brucellosis is a major threat to livestock economy and an important zoonotic disease. A rapid and accurate diagnosis is a necessity to curb the spread and progress of the disease. The current study aimed to evaluate sensitivity of Immunocytochemistry and Immunohistochemistry methods for detection of Brucella spp.Methods: A total of 50 samples comprising of fetal stomach content, vaginal discharges and placenta were collected from cattle and buffaloes suffering from abortions and other reproductive disorders in and around Ludhiana, Punjab during the period 2017-2018. All the samples were processed for isolation and confirmed with biochemical analysis and Polymerase chain reaction (PCR). The isolates obtained and 43 clinical samples excluding placental samples were subjected to Immunocytochemistry (ICC). Immunohistochemistry (ICH) was performed on placental samples.Result: A total of four isolates were recovered from the screened samples. The four isolates also yielded positive results in Immunocytochemistry. Among the 43 clinical samples screened by Immunocytochemistry, five were positive, however only 3 isolates were recovered on isolation. A total of seven placental tissue samples were processed and subjected to immunohistochemistry. Of the three placental samples positive by immunohistochemistry, only one sample was isolated on culture. The results suggest that both immunocytochemistry and immunohistochemistry are sensitive diagnostic techniques in comparison to isolation.

scholarly journals UTILITY OF ANTIGEN DETECTION TEST AND POLYMERASE CHAIN REACTION IN THE DIFFERENTIATION OF TUBERCULOUS AND NON-TUBERCULOUS MYCOBACTERIA

2017 ◽  
Vol 10 (6) ◽  
pp. 289
Author(s):  
Yogita Singh ◽  
Raji Vasanth ◽  
Shrikala Baliga ◽  
Dhanashree B
Keyword(s):  
Polymerase Chain Reaction ◽  
False Negative ◽  
Diagnostic Methods ◽  
Clinical Samples ◽  
Chain Reaction ◽  
College Hospital ◽  
Medical College ◽  
Negative Results ◽  
Polymerase Chain ◽  
Mycobacterium Spp

Objectives: Cultivation and identification of mycobacteria to species level remains difficult and time-consuming. Hence, easy and rapid diagnostic methods are necessary for the differentiation of Mycobacterium tuberculosis (MTB) from non-tuberculous mycobacteria (NTM). The present study aims to detect and differentiate MTB from NTM isolated from clinical samples by immunochromatographic test (ICT) and polymerase chain reaction (PCR). Methods: Over a period of 1 year, clinical samples (n=496) received from suspected cases of TB, at the Department of Microbiology, Kasturba Medical College Hospital, Mangalore were cultured to isolate Mycobacterium spp. Identification of all the isolates was done by conventional biochemical technique, ICT, and PCR. Results: Among the 496 samples processed, 49 (9.87%) were acid-fast bacilli smear positive and 59 (11.89%) samples showed the growth of Mycobacterium spp. Among these, 10 were rapid growers, 49 were slow-growing mycobacteria, out of which 30 were MTB as identified by conventional biochemical reaction. Out of 59 Mycobacterial isolates subjected to ICT for the detection of MPT 64 antigen, only 28 were identified as MTB. However, all the 30 isolates were correctly identified as MTB by PCR. Conclusion: Hence, PCR is essential for rapid differentiation of non-tuberculous Mycobacterium from MTB. False negative results seen with immunochromatographic MPT 64 antigen assay could be due to mutations within the mpt64 gene. Further studies are necessary to characterize these PCR-positive and immunochromatographic assay negative MTB isolates.

scholarly journals Detection of LytA Genes in Streptococcus pneumoniae Isolated from sputum pneumonia patients

Biomedika ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 23-30
Author(s):  
Mustika Sari Hutabarat ◽  
Firdaus Hamid ◽  
Irawaty Djaharuddin ◽  
Alfian Zainuddin ◽  
Rossana Agus ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
False Negative ◽  
Pneumococcal Infection ◽  
Diagnostic Methods ◽  
Molecular Diagnostic ◽  
Clinical Samples ◽  
Biochemical Tests ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain

Streptococcus pneumoniae (pneumococcus) is a Gram-positive facultative anaerobic bacterium that is a major cause of morbidity and mortality worldwide. But the lack of reporting of disease by this bacterium in Indonesia, one of the causes is because the diagnosis of pneumococcal infection is often clinically not typical and conventional methods which are still the standard gold method often give false-negative results. So the purpose of this study was to evaluate the performance of culture and molecular diagnostic methods using the Polymerase Chain Reaction (PCR) technique in detecting Streptococcus pneumoniae in sputum clinical samples using the Autolysin (LytA) gene which is a virulence factor of this bacterium. 57 isolates from 60 samples were confirmed as Streptococcus sp through microscopic identification, culture, and biochemical tests. Then the sensitivity test with an optochin test of 9 (9%) compared the results descriptively with the PCR technique using the Autolysin A (LytA) gene which was obtained more sensitive by 15 (25%).

scholarly journals Electrochemical nanobiosensors perspectives for COVID 19 pandemic

2021 ◽  
Author(s):  
Rajshri Kundlik Satvekar
Keyword(s):  
High Reliability ◽  
Low Cost ◽  
Virus Detection ◽  
Research Area ◽  
Diagnostic Techniques ◽  
Diagnostic Methods ◽  
High Throughput Analysis ◽  
Diagnostic Practices ◽  
Polymerase Chain ◽  
High Degree

Early, rapid and ultrasensitive diagnosis of COVID-19 to facilitate high-throughput analysis without a high degree of technical expertise or sophisticated equipment is necessary to expand COVID-19 testing capability. Leveraging interdisciplinary proficiency in analytical chemistry, biomedical instrumentation, molecular biology, microfluidics, and nanotechnology, considerable advances have been made to develop a novel diagnostic tool that assures superior key performances for COVID-19 diagnosis. This review summarizes the nano-enabled systems such as electrochemical nanobiosensor for SARS-CoV-2 virus detection and emphasizes promising diagnostic techniques to extensively facilitate the diagnostic practices during the COVID-19 pandemic. Currently, three main diagnostic methods have been widely used in the COVID-19 pandemic: nucleic acid (NA)-based testing, computed tomography (CT), and serological testing. NA-based detection of SARS-CoV-2 such as Reverse transcription polymerase chain reaction has become the gold standard for COVID-19 diagnosis. This review congregates significant contributions in the electrochemical nanobiosensor research area, which is helpful for further nanobiosensor development. Although many efforts were taken to detect the SARS-CoV-2, the COVID 19 diagnosis still relies on expensive prolonged analysis. A rapid and reliable alternative is the utilization of a low-cost nanobiosensor for SARS-CoV-2 detection that can rapidly diagnose the disease even in asymptomatic conditions with high reliability and sensitivity.

Influence of euthanasia, the intensity of inflammatory lesion and viral load in the laboratory diagnosis of rabies in cattle

2021 ◽  
Vol 41 ◽  
Author(s):  
Claudia S. Wisser ◽  
Marcélia E.S. Fernandes ◽  
Elaine Melchioretto ◽  
Daiane Ogliari ◽  
Aldo Gava ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Viral Load ◽  
Inflammatory Lesion ◽  
Diagnostic Techniques ◽  
Diagnostic Methods ◽  
Chain Reaction ◽  
Qrt Pcr ◽  
Clinical Evolution ◽  
Early Stages ◽  
Polymerase Chain

ABSTRACT: This research reports the use of different diagnostic tests in cattle, naturally infected by Rabies lyssavirus (RABV), and correlates the positivity of the tests with the clinical moment of euthanasia, the intensity of the inflammatory lesion and viral load. It also highlights the possibility of euthanasia in early stages of the disease as a way to improve animal welfare. For that, samples of 34 bovine brains were collected for analysis, preserved in 10% buffered formaline and refrigerated with subsequent freezing. The samples were subjected to direct immunofluorescence antibody technique (DFAT) tests, viral isolation in cell culture (VICC), histopathology with hematoxylin and eosin staining (HE), immunohistochemistry (IHC), Shorr stainied neural tissue smears (DSS), Reverse transcription polymerase chain reaction (RT-PCR) and polymerase chain reaction by quantitative reverse transcriptase (qRT-PCR). The areas used for analysis were the cerebellum, parietal telencephalon and thalamus. Samples with Negri bodies (NBs) or immunostaining in at least one of the analyzed areas were considered positive. For the study of the intensity of histological lesions, the lesions were classified into grades 0, 1, 2 and 3 and the positivity of the test in the presence or absence of NBs in one of the three areas analyzed. To verify the influence of the disease clinical evolution, 4-four groups of analysis were created according to the animal’s clinical status at moment of the euthanasia, being: M1 = animal euthanized while standing, M2 = euthanized when in sternal recumbence, M3 = euthanized when in lateral recumbence, M4 = animal with natural death. Of the 34 brains evaluated, IHC was positive in 100% of cases, DFAT was positive in 97.05% of them, and in this negative sample the presence of RABV was confirmed by VICC. NBs ere seen in 88.23% of the cases, and the DSS test was positive in 82.35% of them. All diagnostic techniques showed positive cases in all groups analyzed. Each case was positive in at least two diagnostic methods. All cases that contained NBs were positive for rabies in the other tests. In this study, it was observed that the variables analyzed (intensity of injury and clinical evolution at the moment of euthanasia) had an influence only on HE and DSS techniques, which are based on NB research to form the diagnosis, but did not interfere with the effectiveness of the diagnosis performed by detecting the viral antigen performed by DFAT and IHC. All isolated RABV samples included in the present study have a genetic lineage characteristic of hematophagous bats Desmodus rotundus. The evaluation of qRT-PCR showed that the amount of virus did not interfere in the positivity of the tests. This work shows that IHC and DFAT are safe diagnostic techniques. They are capable of detecting RABV even in euthanized animals in the early stages of clinical evolution with mild intensities of histological lesions.

scholarly journals Canine ehrlichiosis: prevalence and epidemiology in northeast Brazil

2015 ◽  
Vol 24 (2) ◽  
pp. 115-121 ◽  
Author(s):  
Paula Elisa Brandão Guedes ◽  
Thais Nascimento de Andrade Oliveira ◽  
Fábio Santos Carvalho ◽  
Renata Santiago Alberto Carlos ◽  
George Rego Albuquerque ◽  
...  
Keyword(s):  
Blood Smear ◽  
Peripheral Blood Smear ◽  
Diagnostic Methods ◽  
Chain Reaction ◽  
Factors Associated ◽  
Molecular Tests ◽  
Canine Ehrlichiosis ◽  
Indirect Immunofluorescent Assay ◽  
Polymerase Chain ◽  
Indirect Immunofluorescent

Ehrlichiosis is a zoonotic disease that is caused by bacteria of the genus Ehrlichia. The aims of this study were to detect the presence of Ehrlichia spp. in the blood of dogs in Ituberá, Bahia, and to compare the sensitivities and specificities of blood smear, serological, and molecular examinations. Furthermore, this study identified factors associated with exposure to the agent in dogs in this locality. Blood samples were collected from 379 dogs and submitted for indirect immunofluorescent assay and polymerase chain reaction testing for the detection of Ehrlichia spp. antibodies and DNA, respectively. Additionally, a peripheral blood smear was obtained from the ear tip for parasite identification. Of the 379 animals, 12.4%, 32.7%, and 25.6% were identified as positive on the blood smear, serological, and molecular tests, respectively. The dogs positive in one of the three techniques were considered exposed (46.9%). Younger dogs and rural habitat were protective factors and presence of ticks and contact with other dogs were the risk factors associated with exposure to the agent. It was concluded that dogs of Ituberá have high positivity for Ehrlichia spp. and that the diagnostic methods used for detection are complementary.

The role of FDG PET/CT discovering the cause of fever of unknown origin

2012 ◽  
Vol 153 (6) ◽  
pp. 227-231
Author(s):  
Bernadett Szűcs ◽  
Edit Nagy ◽  
Stefan Talev ◽  
Ildikó Garai ◽  
László Galuska
Keyword(s):  
Case Report ◽  
Fever Of Unknown Origin ◽  
Unknown Origin ◽  
Diagnostic Procedures ◽  
Clinical Problem ◽  
Diagnostic Techniques ◽  
Diagnostic Methods ◽  
Pet Ct ◽  
Fdg Pet Ct

The fever of unknown origin from time to time constitutes a serious clinical problem and nearly all diagnostic methods are involved to discover urgently its cause. According to literature data 18F-fluoro-deoxyglucose PET/CT was successful in 25-70% of cases even in patients without any positive findings with conventional diagnostic techniques. The Hungarian National Health Fund does not include fever of unknown origin in the list of reimbursed 18F-fluoro-deoxyglucose PET/CT indications. The authors try to illustrate the clinical problem with this case report. Fever of unknown origin persisted in a patient for a year, but conventional diagnostic procedures were unsuccessful to find the cause of the fever. Finally, 18F-fluoro-deoxyglucose PET/CT indicated a metabolically active focus between the pancreas tail and the spleen. After a long-lasting antibiotic therapy the patient became symptomfree. Orv. Hetil., 2012, 153, 227–231.

scholarly journals Role of Cycle Threshold in Clostridioides difficile Polymerase Chain Reaction Testing as a Predictor of Clinical Outcomes in Patients With Inflammatory Bowel Disease

2019 ◽  
Vol 1 (3) ◽  
Author(s):  
Emily R Jonica ◽  
Carol A Sulis ◽  
Kanupriya Soni ◽  
Michelle Hughes ◽  
Eric Jones ◽  
...  
Keyword(s):  
Inflammatory Bowel Disease ◽  
Bowel Disease ◽  
Severe Infection ◽  
Chain Reaction ◽  
Cycle Threshold ◽  
Clostridioides Difficile ◽  
Clostridioides Difficile Infection ◽  
Inflammatory Bowel ◽  
Polymerase Chain

Abstract Background Distinguishing Clostridioides difficile infection from colonization is challenging in patients with Inflammatory Bowel Disease (IBD). Cycle threshold (Ct), the cutoff for PCR positivity, has been investigated in non-IBD patients. Methods Patients with positive C. difficile PCR (25 IBD, 51 non-IBD) were identified retrospectively. Fifteen-day outcomes were assessed. Results Ct correlated with diarrheal days in non-IBD (P = 0.048), but not IBD patients (P = 0.769). IBD patients had shorter LOS and less severe infection, but more diarrheal days (P < 0.05). Conclusions IBD patients had a milder course but Ct results were not significant. Larger studies are needed to clarify utility of Ct in IBD.

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