Fungal Diagnostics

Author(s):  
Shila Seaton ◽  
Rohini J. Manuel

The field of fungal diagnostics encompasses tests that are performed to help diagnose fungal disease, guide its management, and or monitor the effectiveness of its treatment. For some superficial skin and yeast infections, a clinical examination of the patient combined with microscopic examination of the sample may be sufficient to determine that fungal disease is present, even if the specific fungal pathogen is not identified. For deep- seated and systemic infections, a combination of diagnostic tests may be required in order to obtain a definitive diagnosis. These include microscopy to detect fungal elements, culture, detection of circulating antigens and antibodies, and molecular tests. More recently, molecular and proteomic approaches have increasingly dominated the conventional identification of pathogenic yeasts and, to some extent, filamentous fungi, since traditional methods are time consuming. More importantly, conventional methodologies have failed to identify common organisms that display uncharacteristic profiles, or fungal pathogens that are rarely encountered. The ‘gold standard’ for the definitive diagnosis of fungal disease is histology or culture of the fungal pathogen from a clinical specimen. A specimen will routinely be inoculated onto several different types of media, and then incubated at specific conditions and temperatures for up to twenty-one days. Media plates will be examined periodically for growth, and staff will try to identify the fungus using both macroscopic and microscopic morphologies. The few biochemical tests available, e.g. the urease test, can be helpful in identification, most often for yeast species. Microscopy of fungal isolates, histopathological examination of tissue, and fungal specific stains play fundamental roles in the diagnosis of infection for the variety of fungi that cause disease. The most common stain for identifying fungal elements from a cultured isolate is lactophenol fuschin/aniline blue stain. Figure 10.1 depicts the fruiting body (conidiophore) of Aspergillus fumigatus species complex, the most prevalent fungal species responsible for invasive aspergillosis (IA) in severely immunocompromised individuals. Figure 10.2 illustrates the phenotype of a three-day old colony. Serological tests are beneficial when non-culture based diagnosis of fungal disease is required. Complement fixation is predominantly used to diagnose endemic mycoses, e.g. coccidioidomycosis, blastomycosis, and histoplasmosis.

2021 ◽  
Vol 8 (2) ◽  
pp. 136-145
Author(s):  
Maharani Pertiwi K. ◽  
◽  
Ayu Slatim Maifanda ◽  
Amalia Ayu Febrianti ◽  
Nabila Ina Zahra ◽  
...  

Introduction: Nosocomial infections are infections caused by microbial such as bacteria, viruses, and fungi.that are acquired during the process of receiving health care. Diagnostic techniques for the examination of nosocomial infections play an important role in determining the accuracy of the infection of microorganisms causing infectious agents, so that the treatment given can be appropriate and minimize drug resistance. Purpose: This literature review is structured to provide an overview of diagnostic techniques fornosokomialinfection using conventional and advanced methods. Methods: The preparation of this review is based on the development of diagnostic techniques in the medical laboratory. Results: Conventional diagnostic techniques are generally carried out bymeans of culture on artificial media, macroscopic observations and biochemical tests. Further tests that can be applied are serological tests, antigen tests, and molecular tests such as PCR techniques. Conclusion: Conventional diagnostic techniques for microbiological examination of nosococomial infections require further tests to help establish a rapid and accurate diagnosis.


Author(s):  
Rebecca Lester ◽  
John Rex

Invasive fungal disease can present without localization or obvious target organ involvement. These disseminated mycoses occur predominantly in patients who are immunocompromised, particularly from haematological malignancy and HIV. Candidiasis and aspergillosis are the commonest forms of disseminated fungal infection worldwide, but an increasing number of non-Candida yeasts and non-Aspergillus moulds have emerged as important causes of invasive disease in recent years. Endemic fungi such as Histoplasma capsulatum are important causes of invasive disease within limited geographic regions. Fever is the commonest manifestation of disseminated fungal infection, but other clinical features such as cutaneous manifestations may point to a specific diagnosis. Definitive diagnosis relies on the detection of fungi in tissue or blood, but serological tests can augment diagnosis in some infections. Mortality from disseminated fungal disease is high and prompt initiation of antifungal therapy—where invasive disease is suspected—is essential.


2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Yasmin ElTahir ◽  
Anfal Al-Farsi ◽  
Waleed Al-Marzooqi ◽  
Alghalya Al-Toobi ◽  
Osman M. Gaafar ◽  
...  

Abstract Background The objective of this study was to investigate Brucella infection in farm animals in Saham, Oman, with reference to a survey carried out by the Ministry of Agriculture & Fisheries (MAF) for Brucellosis during the period of May to July 2016 in Saham, following an outbreak of human brucellosis. We wanted to apply different serological, bacteriological and molecular tests in a time frame (phase 1, 2 & 3) with reference to the pivotal time of a human brucellosis outbreak to ascertain the status of the disease in Saham area where the MAF survey was conducted. Blood samples were collected from farm animals and sera were screened in parallel for Brucella antibodies using different serological tests. Results Using the RBT test, phase 1 sera showed seropositivity in sheep at 2.6%, (95% CI: 0.5–13.5%), in camel (5.9%, 1.1–27.0%), but not in sera from goats and cattle (0%). Using I-ELISA, seropositivity in goat was 3.1% (0.6–15.8%), with no positive sheep and cattle. Using c-ELISA for camel we found a seropositivity of 5.9% (1.1–27.0%). Furthermore, CFT seropositivity in goats was 21.9% (CI: 11.3–38.9), cattle and sheep sera were negative and camel was 5.9% (1.1–27.0%). In phase 2, the seropositivity in goats was 1.9% (1.4–2.6%), sheep 4.5% (3.5–5.8%), cattle 1.1%, (0.5–2.3%) and camels 18.2% (5.1–47.7%), Phase 3 sera were collected 6 months after the human brucellosis outbreak. With RBT, the seropositivity in goats was 3% (1.0–8.5%), sheep 2% (0.6–7.1%) cattle 1% (0.2–5.5%). With I-ELISA, goats & camels were negative, sheep were 3% (1.0–8.5%) and cattle 1% (0.2–5.5%). Moreover, B. melitensis was isolated from a bronchial lymph node of the RBT and I-ELISA seropositive cow and confirmed by Multiplex PCR and biochemical tests. Conclusion Using a retrospective study analysis of animal sera and following up after a human brucellosis outbreak, the present study showed a slight decrease in seropositivity of infected animals after the MAF implemented test and slaughter policy. The most interesting finding in this study was the isolation, identification and molecular characterization of Brucella melitensis in a cow (spillover), which is not a preferential host for Brucella melitensis.


2018 ◽  
Vol 69 (7) ◽  
pp. 1813-1816 ◽  
Author(s):  
Ovidiu Gabriel Bratu ◽  
Radu Dragos Marcu ◽  
Bogdan Socea ◽  
Tiberiu Paul Neagu ◽  
Camelia Cristina Diaconu ◽  
...  

Retroperitoneal space is called sometimes no man�s land�and for a good reason: this is disputed anatomical territory for many surgical and medical specialties. Their wide histological diversity and unspecific clinical presentation make them a challenge for the surgeon. In order to improve their detection immunohistochemistry seems to show promising results. Methods of detection have evolved over time to identify as much as possible the histological type of tumor. Because of this extreme variability immunohistochemistry through its various markers is the one that often sets the definitive diagnosis, the simple histopathological examination being insufficient. This paper aims to highlight the main markers used in retroperitoneal tumors. As it can be seen there is a huge histologic areal for these tumors. Some have proven some of them still not. Given the fact that there is a tendency toward personalized therapy it is imperative to identify the histological type of tumor as soon as possible.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1530.1-1530
Author(s):  
G. Kaynar ◽  
O. C. İçaçan ◽  
S. Çelik ◽  
M. Yalçin Mutlu ◽  
C. Bes

Background:Purpura are lesions that occur after bleeding on the skin, mucous or serosal surfaces. Purpura can be classified into 2 subgroups; which are linked to thrombocytopenia and non-trombocytopenic purpura. While thrombocytopenic purpura often occurs due to a hematological disease; in non-trombocytopenic purpura etiological causes are very variable, and systemic vasculitis has an important place among them.Objectives:The demographic features of the patients applying with purpura and the underlying causes and diseases were aimed to be revealed.Methods:44 consecutive patients (22 women, 22 men) who were admitted to the hospital in the last 6 months, due to purpura were evaluated. Average age of patients was 49.6 ± 19.6 years. Patients were questioned about a recent infection, drug use, concomitant or underlying diseases. The serological tests and other laboratory tests for etiology were performed and biopsy was taken from the skin lesions which are appropriate.Results:While 4 (9%) patients had widespread purpura on the trunk-upper-lower extremities, in 22 (50%) patients purpuric lesions were limited only to the lower limb. The period between the onset of the first symptom and the admission to the hospital was longer than 4 weeks in 35 (79.5%) patients, and shorter than 1 week in 9 (20.5%) patients. 24 (54%) patients had an anamnesis of infection 2-3 weeks before purpura, and 20 (45%) patients had an anamnesis of drug use. The most common accompanying symptom was abdominal pain and was present in 15 (34%) patients. Biopsy was performed from the skin lesion in 37 patients. Histopathological examination of all was compatible with leukocytoclastic vasculitis. In indirect immunofluorescence staining, 17 were found to be IgA positive. 2 (4.5%) patients were diagnosed PR3-ANCA positive granulomatosis with polyangiitis. 1 patient had Hepatitis B virus infection was detected in 1 patient (2.2%), HIV infection was detected in 1 patient (2.2%) and malignancy was detected in 1 patient (2.2%).Conclusion:In our study, the most common reason was found as IgA vasculitis in patients presenting with palpable purpura. Although vasculitic involvement was limited to the skin in most patients, organ-threatening systemic vasculitis was detected in a few patients. Patients applying with Purpura should be questioned for infection and drug use, should be examined for underlying diseases including systemic vasculitis, and closely monitored for organ involvement.Disclosure of Interests:None declared


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Emily R. Adams ◽  
Inge Versteeg ◽  
Mariska M. G. Leeflang

Identification of post-kala-azar dermal leishmaniasis (PKDL) is important due to the long and toxic treatment and the fact that PKDL patients may serve as a reservoir for visceral leishmaniasis (VL). We summarized the published literature about the accuracy of diagnostic tests for PKDL. We searched Medline for eligible studies investigating the diagnostic accuracy of any test for PKDL. Study quality was assessed using QUADAS-2. Data were extracted from 21 articles including 43 separate studies. Twenty-seven studies evaluated serological tests (rK39 dipstick, ELISA, DAT, and leishmanin tests), six studies molecular tests, eight microscopy, and two cultures. Only a few of these studies reported a valid estimate of diagnostic accuracy, as most were case-control designs or used a reference standard with low sensitivity. The included studies were very heterogeneous, for example, due to a large variety of reference standards used. Hence, no summary estimates of sensitivity or specificity could be made. We recommend well-designed diagnostic accuracy trials that evaluate, side-by-side, all currently available diagnostics, including clinical symptoms, serological, antigen, molecular, and parasitological tests and possible use of statistical modelling to evaluate diagnostics when there is no suitable gold standard.


2016 ◽  
Vol 1 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Sofiane El-Kirat-Chatel ◽  
Yves F. Dufrêne

We establish atomic force microscopy as a new nanoscopy platform for quantifying the forces between fungal pathogens and immune cells.


2001 ◽  
Vol 15 (5) ◽  
pp. 327-331 ◽  
Author(s):  
Isam Alobid ◽  
Manuel Bernal ◽  
Carlos Calvo ◽  
Isabel Vilaseca ◽  
Juan Berenguer ◽  
...  

Rhinocerebral mucormycosis (RCM) is an aggressive fungal infection with a high mortality rate. It frequently develops in patients with uncontrolled diabetes mellitus or immunocompromised patients. RCM typically presents in a rapidly fulminant manner with headache, fever, mucosal necrosis, and ophthalmic symptoms. Although the definitive diagnosis is achieved by histopathological examination, computed tomography (CT) scanning and magnetic resonance (MR) are the best imaging procedures in early diagnosis to assess the extent of the disease.


2021 ◽  
Vol 15 (4) ◽  
pp. 281-286
Author(s):  
Guilherme Mantuani Silva ◽  
Isabela Cristina de Oliveira ◽  
Rodrigo Samuel de Toledo ◽  
Juliana Evangelista Bezerril ◽  
Gabriela Maria Benedetti Vasques ◽  
...  

The most common testicular neoplasms in dogs are seminoma, leydigocytoma and sertolioma, affecting middle--aged and elderly dogs, where cryptorchidism is a predisposing factor, as well as some breeds. It can occur alone or, less fren-quently, concurrently, generally affecting the same testicle. This study aimed to report the case of a non-cryptorchid 14-year--old mixed breed dog diagnosed with seminoma and sertolioma, each in a testicle. The animal showed an increase in scrotal volume, with no changes in other clinical parameters on physical examination. On ultrasound examination, it was possible to observe alterations suggestive of neoplasia in both testicles and prostatic alteration suggestive of benign prostatic hyperplasia. Complementary blood count and biochemical tests were performed and, as treatment, orchiectomy was performed. Fragments were collected from both testicles and sent for histopathological examination. Microscopy of the left testicle showed the presence of round cells, multiple and evident nucleoli, cells in different phases of mitosis and binucleation, these changes being compa-tible with seminoma. In contrast, in the right testicle, spindle and elongated cells (pseudo-lobular) were observed, presence of long cytoplasmic projections with rounded ovoid nucleus, spindle cells and degeneration of seminiferous tubules, compatible with sertolioma. It was observed that physical examination associated with ultrasound was efficient to detect the presence of neoplasms, being validated by histopathological examination. Orchiectomy was an assertive treatment indicated for this case.


EUGENIA ◽  
2011 ◽  
Vol 17 (3) ◽  
Author(s):  
Emmy Senewe ◽  
Guntur Manengkey

ABSTRACT Leptocorisa oratorius is one major pest of rice in North Sulawesi. Hence, it is necessary to control the pest. The research objective was to identify and to test pathogenicity of local  entomopathogen fungi which infected  Leptocorisa oratorius. The pathogens were collected through sampling of L. oratorius which had been infected by the fungi in the field. The pathogenic fungi was isolated using PDA medium, identified followed by inoculation for pathogenecity test.  During several sampling pest, it was found that  L. oratorius was attacked by fungal pathogens in the field. The identification revelead that the fungal pathogens were Beauveria sp and Fusarium sp. Both the fungal pathogen produced white mycelium and could only be distinguished using microscope in the laboratory. Result of pathogenicity tests showed that the two fungal pathogens caused different mortality of the L. oratorius. Mortality of  L. oratorius caused by pathogenic fungus Beauveria sp was  30.3% . Whereas, mortality of  L. oratorius caused by Fusarium sp was only 3.33%. Keywords : pathogenic fungi, entomopathogen, pathogenicity tests, L. oratorius


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