Galactomannan Antigen Detection Research Articles

Specific Parameters of Detection of Fungi of the Genus <i>Aspergillus</i> in Respiratory Organs of Pulmonary Tuberculosis Patients

The objective: to study specific parameters of detection of fungi of the genus Aspergillus in respiratory organs of pulmonary tuberculosis patients.Subjects and Methods. In 2019-2021, the samples of sputum or bronchoalveolar lavage of 520 patients above 18 years old with confirmed pulmonary tuberculosis and HIV-negative status were tested for molds. Also, all patients had their sputum or BAL tested for acid fast mycobacteria (AFB), cultures of M. tuberculosis (MBT), and DNA of tuberculous mycobacteria.Results. Positive culture results for fungi were obtained in 50/520 (9.62%; 95% CI 7.37-12.45, Wilson test) pulmonary tuberculosis patients. Species identification revealed fungi of the genus Aspergillus in 46/50 (92%) of them.In 37/46 (80.43%; 95% CI 66.83-89.35) patients, a single type (one species of Aspergillus) was identified, in 9/46 (19.57%; 95% CI 10.65-33.17) two types were identified. A. fumigatus (16/37 isolates, 43.24%) and A. niger (13/37 isolates, 35.14%) prevailed among single types of cultures. A. niger + A. flavus (3/9 isolates, 33.33%) was the most frequent combination. The ratio of the effectiveness of methods for detecting fungi such as culture/direct microscopy/galactomannan antigen in serum and BAL was 100/84.78/4.35% and 67.39%, respectively. Thus, BAL is more preferable than serum for detection of galactomannan antigen in patients with tuberculosis.Only in 8/46 (17.4%) patients, bacterial excretion was detected by culture, which is typical for the active phase of the course of tuberculosis. In the remaining 38 (82.6% 95% CI 69.28-90.91) patients, no tuberculous mycobacteria were detected by culture, which was typical of stabilization and cure of tuberculosis.

Lateral flow assay (LFA) in the diagnosis of COVID-19-associated pulmonary aspergillosis (CAPA): a single-center experience

BackgroundInvasive pulmonary aspergillosis (IPA) is seen during coronavirus-2019 (COVID-19), has been reported in different incidences, and is defined as COVID-19-associated pulmonary aspergillosis (CAPA). Detection of galactomannan antigen is an important diagnostic step in diagnosing IPA. Enzyme-linked immunoassay (ELISA) is the most frequently used method, and lateral flow assay (LFA) is increasingly used with high sensitivity and specificity for rapid diagnosis. The present study aimed to compare the sensitivity of LFA and ELISA in the diagnosis of CAPA in COVID-19 patients followed in our hospital's ICU for pandemic (ICU-P).MethodsThis study included patients with a diagnosis of COVID-19 cases confirmed by polymerase chain reaction and were followed up in ICU-P between August 2021 and February 2022 with acute respiratory failure. The diagnosis of CAPA was based on the European Confederation of Medical Mycology (ECMM) and the International Society for Human and Animal Mycology 2020 (ECMM/ ISHAM) guideline. Galactomannan levels were determined using LFA and ELISA in serum samples taken simultaneously from the patients.ResultsOut of the 174 patients followed in the ICU-P, 56 did not meet any criteria for CAPA and were excluded from the analysis. The rate of patients diagnosed with proven CAPA was 5.7% (10 patients). A statistically significant result was obtained with LFA for the cut-off value of 0.5 ODI in the diagnosis of CAPA (p < 0.001). The same significant statistical relationship was found for the cut-off value of 1.0 ODI for the ELISA (p < 0.01). The sensitivity of LFA was 80% (95% CI: 0.55–1.05, p < 0.05), specificity 94% (95% CI: 0.89–0.98, p < 0.05); PPV 53% (95% CI: 0.28–0.79, p > 0.05) and NPV was 98% (95% CI: 0.95–1.01, p < 0.05). The risk of death was 1.66 (HR: 1.66, 95% CI: 1.02–2.86, p < 0.05) times higher in patients with an LFA result of ≥ 0.5 ODI than those with < 0.5 (p < 0.05).ConclusionsIt is reckoned that LFA can be used in future clinical practice, particularly given its effectiveness in patients with hematological malignancies and accuracy in diagnosing CAPA.

RAPID DEVELOPMENT AND PROGRESSION OF INVASIVE PULMONARY ASPERGILLOSIS

RAPID DEVELOPMENT AND PROGRESSION OF INVASIVE PULMONARY ASPERGILLOSIS

Sandwich-type homogeneous chemiluminescence immunoassay based on nanoparticle toward detection of Aspergillus galactomannan antigen

Aspergillus species continue to be an important cause of life-threatening infection in immunocompromised patients and galactomannan (GM) is a popular biomarker in the diagnosis of invasive aspergillosis (IA). Here we developed and validated an amplified luminescent proximity homogenous assay-linked immunosorbent assay (AlphaLISA) for serum and bronchoalveolar fluid (BALF) GM based on this approach. Technological processes and reaction conditions were optimized. Study assessments included reproducibility, accuracy, stability, and cross reactivity experiments. Method comparisons with the commercial Platelia Aspergillus enzyme immunoassay (Bio-Rad Laboratories) were performed using 201 clinical serum and BALF samples. Under the optimized conditions, the total runtime of the AlphaLISA method was 40 min with simple operation. The percent coefficient variations (CVs%) were lower than 15%, and the recoveries were in the range of 90–110%. Of note, the proposed assay exhibited acceptable stability and did not display cross-reactivity with non-Aspergillus pathogens. Compared with the results from the Platelia kit, there was a satisfied overall qualitative agreement of 97.5% and overall quantitative correlation coefficient of 0.59. In all, we have successfully developed an alternative novel homogeneous nanoparticle-based immunoassay, which has shorter incubation time and easier protocol than the ones of conventional ELISA. It could serve as an alternative to the well-established Platelia assay for measurement of GM in serum and BALF.

Comparison of the Performance of Two Galactomannan Detection Tests: Platelia Aspergillus Ag and Aspergillus Galactomannan Ag Virclia Monotest.

ABSTRACTThe use of nonculture-based biomarkers such as the determination of galactomannan is sought for the diagnosis of invasive aspergillosis. To investigate the comparative yield of two tests for the detection of galactomannan in patients with or without proven or probable invasive aspergillosis. Overall, 327 samples (327 patients) were analyzed in a retrospective/prospective study performed in 3 hospitals in Madrid, comparing the determination results in serum or bronchoalveolar lavage of two techniques for galactomannan detection, namely, Platelia Aspergillus Ag (Bio-Rad) and Aspergillus galactomannan Ag Virclia Monotest (Vircell S.L.), following the manufacturer’s instructions. Both techniques can automate the process, but the second technique has the advantage of individual processing and assembly of each sample without the need for the additional expense of single-dose strips in controls. In total, 288 of the 327 tests performed showed concordant results between both techniques. The agreement between both methods was к = 0.722, and the correlation between indices was ρ = 0.718. Only 39 samples showed discordant results. In those 39 cases, there were 15 patients with proven or probable invasive aspergillosis criteria. For the samples with clinical criteria as a reference, the areas under the curve of the receiver operating characteristic (ROC) curve were 0.962 for Platelia and 0.968 for VirClia. The VirClia test has been proven to be an alternative for diagnosis due to its friendlier automated format than that of the usual Platelia routine test. The VirClia test also allows individual action and, therefore, a more immediate clinical response.IMPORTANCE Invasive mycoses are increasingly present in immunosuppressed or hospitalized patients with serious illnesses, leading to high rates of morbidity and mortality. Invasive aspergillosis is an infection caused, in a percentage greater than 50%, by the genus Aspergillus. It is vitally important to make an early diagnosis that leads to the application of antifungals in the initial stage of the infection. Therefore, tools are required to help with the early diagnosis of the infection. This comparative study of two enzyme immunoassays is based on the detection of galactomannan antigen in serum and bronchoalveolar lavage samples. A new design based on chemiluminescence and presented in an automated single-dose format is compared to a conventional ELISA technique marketed for years. The results obtained from the prospective and retrospective study indicate a high correlation and degree of agreement between both techniques, as well as in their diagnostic performance.

721. Diagnosis of Histoplasmosis Using the MVista Histoplasma Galactomannan Antigen Qualitative Lateral Flow-Based Immunoassay; A Multicenter Study

Abstract Background Accurate and timely methods for the diagnosis of histoplasmosis in endemic resource-limited settings are largely lacking. Histoplasma galactomannan antigen detection by enzyme immunoassay (EIA) is the most widely used method for the diagnosis of acute pulmonary and disseminated histoplasmosis in the United States (USA). EIA methods have constraints in resource-limited settings including cost, turnaround time, and the need for large reference laboratories, leading to missed or delayed diagnoses and poor outcomes. Lateral flow assays (LFA) are practical methods that can be used in this setting for Histoplasma antigen detection. Methods Frozen urine specimens were submitted to MiraVista (MVista) for Histoplasma antigen EIA testing from three academic medical centers in highly endemic areas of the USA. They were also blinded and tested for the MVista Histoplasma LFA by skilled MVista technologists. Medical records were reviewed for clinical information. Patients were classified as controls or cases of histoplasmosis. Cases were divided into proven or probable, pulmonary, or disseminated, immune competent or immune suppressed, and mild, moderate, or severe. Results 352 subjects were enrolled, including 66 cases of histoplasmosis (44 proven, 22 probable) and 286 controls. Most of the cases were immunocompromised (68%). 76% had disseminated histoplasmosis. 6% were mild, 66% moderate, and 28% severe. A high degree of concordance was found between LFA and EIA results (kappa 0.837, OR 372.7, LR 204, p&amp;lt; 0.001). Overall, the sensitivity and specificity of the LFA were 78.8% and 99.3% respectively (kappa 0.84, p&amp;lt; 0.001). The sensitivity was higher in proven cases (93.2%), in patient with disseminated (94.7%), moderate (80%) and severe disease (94%), and those with galactomannan levels ≥ 2 ng/mL (97.7%). Specificity was 99.3% in proven cases, 99.3% in patient with moderate and severe disease, and 96.4% in those with galactomannan levels ≥ 2 ng/mL. Table 1. Statistical characteristics of the LFA test for histoplasmosis in different categories. PPV: Positive Predictive Value. NPV: Negative Predictive Value. EIA: Enzyme Immunoassay. The LFA test for histoplasmosis is more accurate in patients with high burden of infection. Conclusion The MVista Histoplasma galactomannan LFA may meet the need for accurate rapid diagnosis of histoplasmosis in resource-limited settings, especially in patients with relatively high disease burden, potentially reducing morbidity and mortality. Disclosures Melissa Minderman, Bachelor's Degree, Molecular Biology, MiraVista Diagnostics (Employee) Suphansa Gunn, Bachelor's Degree, psychology, MiraVista Diagnostics (Employee) Lawrence J. Wheat, MD, MiraVista Diagnostics (Employee)

Early diagnosis of aspergillosis in asthmatic and rheumatoid arthritis patients by Aspergillus galactomannan antigen assay: a case-control study in Karbala providence

Objective Aspergillosis is an opportunistic systemic infection caused by members of Aspergillus spp. in various parts of the human body. Chronic diseases such as rheumatoid arthritis (RA) and asthma may encourage the development of aspergillosis under specific conditions. Thus, aspergillosis was investigated in patients with RA and asthma based on detection of galactomannan antigen. Methods A case-control study was performed to involve 184 subjects, distributing in four groups: 55 patients with RA, 54 with asthma, 27 with both RA and asthma, and 48 healthy individuals. Serum was collected from involved subjects for detection of human Aspergillus galactomannan by ELISA. The optical density index (ODI) at cutoff <0.5 was used to determine the infection. Results Aspergillosis was more frequently diagnosed in females with RA and both RA and asthma in opposite to the males. It also was found in most common in middle-aged subjects. There was no significant difference in measurement of GM between all patient groups and healthy individuals. Conclusion Aspergillosis can develop in either immunocompetent or immunocompromised individuals. Patients with either RA or RA and asthma are more susceptible to acquired aspergillosis than those with only one disease. Application of GM for diagnosis of aspergillosis may show a nonsignificant results when it uses alone and needs other investigation tests.

Investigation and analysis of questionnaire on clinical thinking in the diagnosis of severe infection in Guangxi

To understand the clinical thinking of clinical staff in the diagnosis of severe infection and evaluate their ability to recognize severe infection in the early stage. A questionnaire survey was conducted to investigate the clinical thinking of clinical staff attending the academic annual meeting of critical care physicians of Guangxi Medical Doctors Association from September 26 to September 28, 2019. The objects of investigation included doctors, nurses, clinical pharmacists and medical graduate students, except for non-clinical personnel. The basis factors of clinical diagnosis of infection included clinical symptoms, specific biochemical examination, microorganism examination and Next-generation sequencing technology (NGS). The credibility level of each indicator was summarized as high (credibility of 51%-100%) and low (credibility of 0%-50%). Among the more than 600 participants, 540 people participated in the questionnaire survey (participation rate of about 90.0%), and 466 qualified questionnaires (effective rate of 86.3%) were collected, including 280 from doctors, 155 from clinical nurses, 10 from clinical pharmacists and 21 from clinical graduate students. The working years of doctors, nurses, clinical pharmacists and medical graduate students were (8.2±6.0), (6.4±6.3), (4.5±4.0) and (3.8±2.6) years, respectively. The intermediate title (43.2%) dominated in the doctors group, while junior title dominated in the nurses group, clinical pharmacists group and medical postgraduate group (53.5%, 80.0% and 81.0% respectively). Doctors and nurses were mainly from the general intensive care unit (ICU; 73.2% and 51.0% respectively). According to the results of investigation of clinical thinking on the diagnosis of severe infection, there was similar degree of recognition and credibility for infection-related symptoms in the four groups of doctors, nurses, clinical pharmacists and medical graduate students (the credibility of fever was 80.0%-91.1%, low blood pressure 76.2%-90.0%, disturbance of consciousness 80.0%-85.0%, breathing 81.0%-100.0%, reduced of urine 81.9%-90.0%). The interpretation for pathogen culture and NGS results was insufficient because 29.3%-42.6% of the medical staff did not understand NGS. There were differences in the interpretation of the results of pathogen culture (positive specimen culture could diagnose infection; medical vs. nursing vs. pharmacists vs. student: 93.6% vs. 85.2% vs. 90.0% vs. 85.7%, P = 0.021). There were significant differences among the four groups in some traditional infection-related laboratory indexes which included increased white blood cell count (WBC; χ2 = 8.542, P = 0.026), increased C-reactive protein (CRP; χ2 = 8.826, P = 0.024), increased interleukin-6 (IL-6; χ2 = 13.944, P = 0.002), positive 1, 3-β-D glucan detection test (G test; χ2 = 10.988, P = 0.009) and positive galactomannan antigen detection test (GM test; χ2 = 12.306, P = 0.004). There is difference in clinical thinking of diagnosis of severe infection among clinical medical staff in different positions, and the comprehensive diagnostic ability needs to be improved.

Prospective observational study of respiratory Aspergillus colonization or disease in patients with various stages of chronic obstructive pulmonary disease utilizing culture versus nonculture techniques.

COPD is a risk factor for Aspergillus spp. colonization. Bronchoalveolar lavage samples of 150 COPD patients were tested for presence of Aspergillus fumigatus, which was detected in five patients (3.3%) by culture, but detection of Aspergillus increased to 17 (11.3%) by additional GM and PCR testing.

Role of Aspergillus Galactomannan Antigen Test for the Screening of Invasive Aspergillosis in Patients with Hematological Malignancies

Background: Invasive aspergillosis (IA) is a leading cause of death among immunocompromised patients, particularly those with hematological malignancies. The use of galactomannan (GM) antigen as a biological marker for screening of IA in high-risk patients is attractive and non-invasive tool that detect evidence of IA prior to the appearance of clinical manifestations.&#x0D; Objectives: The aim of this study was to compare the diagnostic value of the conventional blood culture technique to the serological detection of GM antigen using ELISA for screening of IA in neutropenic patients with hematological malignancies.&#x0D; Methods: Forty patients with haematological malignancies from those admitted to the Clinical Oncology Department of Menoufia University Hospitals (MUH) were enrolled and classified to have either proven (5/40; 12.5%), probable (10/40; 25%) or possible (25/40; 62.5%) invasive aspergillosis based on the clinical criteria provided by the European Organization for research and treatment of Cancer (EORTC) and Mycoses Study Group (MSG). Blood samples were collected from all participants and subjected to conventional blood culture for isolation and identification of Aspergillus spp. ELISA technique was applied for serological detection of GM antigen in the patients’ serum samples.&#x0D; Results: The sensitivity, specificity, PPV(positive predictive value) and NPV (negative predictive value of GM antigen ELISA testing were 100%, 74%, 36% and 100% respectively for both proven and probable cases. On applying the principle of test in series (the patient is positive if positive in both culture and the GM test), the results were improved to 100% sensitivity, 100% specificity, 100% PPV, 100% NPV and 100% accuracy. Galactomannan antigen testing proved excellent sensitivity (80%) compared to other clinical features and radiological criteria for diagnosis of probable aspergillosis and proved to be a good negative test.&#x0D; Conclusion: With conjunction of clinical and radiological signs, Aspergillus GM test can assist physicians in the of diagnosis of IA in patients with hematological malignancies to allow initiation of effective antifungal therapy which is ultimately important in high-risk populations.

Cross-sectional study of respiratory Aspergillus spp. colonization or infection in patients with various stages of chronic obstructive pulmonary disease (COPD) using culture vs non-culture based technique

Background COPD patients are now recognized to be at increased risk of colonization by Aspergillus spp. which may progress to invasive pulmonary aspergillosis (IA). Published data on the frequency of Aspergillus detection in COPD are limited. Methods A cross-sectional study was undertaken to determine Aspergillus colonization or infection in COPD patients undergoing bronchoscopy for any indication. Culture as well as galactomannan antigen (GM) and Aspergillus nucleic acid detection (PCR) were performed on bronchoalveolar lavage fluid (BAL). Results One hundred and fifty patients were included (44.7 % female, mean age 68.2 years). 21.3 % were inpatients, 74.7 % outpatients and 4 % were ICU patients. Investigation of lung masses was the most common indication (43.3 %) for bronchoscopy. Most patients (81.3 %) were either GOLD stage 1 or 2 COPD. Cancer was the most frequent co-morbidity (60.48 %). 12 % and 48.7 % were on systemic and inhaled steroids respectively. Lung mass was the most common (28.43 %) CT imaging finding. Seventeen patients (11.3 %) had a positive result for Aspergillus (Culture+Galactomannan+PCR). 76.4 % out of these seventeen were in the early stages (GOLD stage 1 or 2) of COPD. Conclusion Aspergillus sp. was detected in 3.3 % of patients by culture, which increased to 11.3 % if culture was combined with either a positive GM or PCR result. Overall the frequency of Aspergillus detection in this population of COPD patients was low which may reflect the predominance of Gold stages 1 and 2 among the study population.

APPLICATION OF 3-HYDROXYBUTYRATE MEASUREMENT AND PLASMA PROTEIN ELECTROPHORESIS IN THE DIAGNOSIS OF ASPERGILLOSIS IN AFRICAN PENGUINS ( SPHENISCUS DEMERSUS).

New alternative laboratory means are needed to improve the options for antemortem diagnosis of avian aspergillosis. In this study, 3-hydroxybutyrate was measured in plasma samples collected from a cohort of African penguins ( Spheniscus demersus) maintained under human care. Results were interpreted in combination with those of protein electrophoresis and compared with anti- Aspergillus antibody and galactomannan antigen detection. Overall, 3-hydroxybutyrate levels were found significantly increased in Aspergillus-diseased cases versus the control penguin group ( P = 0.002). Mean absolute concentration of β-globulins was increased >20% in samples from infected birds, and α2-globublins were also found to be significantly increased versus clinically normal controls ( P < 0.001 and P = 0.001 respectively). Of note, the α2-globulins were also significantly increased versus penguins with inflammatory (non-aspergillosis) diseases ( P = 0.001). The specificity of 3-hydroxybutyrate, β-globulins, and α2-globulins for aspergillosis was 78.6%, 79.6%, and 92.2%, respectively. Using these measures in tandem resulted in high specificity (>90%) and negative predictive value (≥80%). In contrast, anti- Aspergillus antibody and galactomannan antigen did not distinguish between infected cases and controls ( P > 0.05). This study demonstrates that basic testing in tandem with the new biomarker 3-hydroxybutyrate may provide reliable evidence for the diagnosis of aspergillosis in penguins.

Use of Galactomannan Antigen and Aspergillus DNA Real-time Polymerase Chain Reaction as Routine Methods for Invasive Aspergillosis in Immunosuppressed Children in Greece

PurposeInvasive aspergillosis (IA) remains a critical issue in immunosuppressed patients. Detection of galactomannan antigen (GM) in serum samples is included as a criterion of IA by the European Organization for the Research and Treatment of Cancer/Mycoses Study Group. Nevertheless, Aspergillus DNA detection by polymerase chain reaction (PCR) has not yet been included because clinical data validation is lacking. The present study describes the simultaneous performance of GM and PCR tests as routine methods for IA diagnosis. MethodsDuring the period January 2012 to December 2017, a total of 156 white children hospitalized in a tertiary children’s hospital of Athens (97 boys and 59 girls; age range, 5 months–14 years) were examined as possible cases of IA. Patients were classified into 4 groups based on their underlying diseases: hematologic malignancies (107 of 156 [68.6%]), solid tumors (16 of 156 [10.2%]), primary immunodeficiency (12 of 156 [7.7%]), and hereditary immunodeficiency (21 of 156 [13.5%]). GM detection was made with the Platelia Aspergillus Ag kit (Bio-Rad Laboratories, Hercules, California). Sera with a cut-off index ≥0.5 on at least 2 separate blood collections were considered positive. Serum detection of Aspergillus DNA was conducted with real-time PCR MycAssay Aspergillus assay (Myconostica Ltd, Cambridge, United Kingdom). PCR positivity was determined by using a threshold of 38 cycles in at least 1 serum sample. Four or more successive samples per patient were tested. FindingsOverall, 28 of 156 patients (53 of 744 serum samples) were found positive. Eleven patients were positive using both methods (24 samples). Four children were positive only by PCR (6 samples), whereas 13 (23 samples) were positive only with GM in consecutive samples. Agreement of both methods, GM(+)/PCR(+) or GM(–)/PCR(–), was found in 139 patients (90% of total patients) and 715 samples (96.1% of total samples). The agreement of both methods was found: (1) 85% in patients with hematologic malignancies; (2) 100% in patients with solid tumors; (3) 97.5% in patients with primary immunodeficiency; and (4) 98.8% in patients with hereditary immunodeficiency. Overall disagreement was observed in 17 patients, in which the positive result in any of the 2 methods was estimated as true positive in conjunction with radiologic and other clinical findings. ImplicationsThe combination of GM and PCR, provided high diagnostic accuracy in consecutive samples (twice a week). Clinical, radiologic, and other laboratory findings should be taken into consideration in the evaluation of GM and PCR.

Galactomannan antigen detection as a screening tool for early diagnosis of invasive aspergillosis: Experience of Turkish adult patients

Galactomannan antigen detection as a screening tool for early diagnosis of invasive aspergillosis: Experience of Turkish adult patients

Mycological and Serological Study of Invasive Aspergillosis in A Tertiary Care Hospital

Objectives: Invasive&#x0D; aspergillosis (IA) has emerged as a major life threatening infection in high&#x0D; risk patients. Recent advances have led to early diagnosis of IA by detecting Aspergillus antigens in serum&#x0D; particularly Galactomannan (GM). Objective of the study was to correlate fungal&#x0D; smear, culture and Galactomannan assay in patients with suspected IA and to&#x0D; categorize them into “proven,” “probable,” and “possible,” cases as per&#x0D; European Organization for Research and Treatment of Cancer and Mycoses study&#x0D; group case definitions (EORTC/MSG) criteria. &#x0D; &#x0D; Methods: The prospective&#x0D; study was conducted over a period of one year in the department of&#x0D; Microbiology, Dayanand Medical College and Hospital, Ludhiana. A total of 319&#x0D; patients with suspicion of IA were included in the study. GM antigen detection&#x0D; test was done from serum samples. KOH mount was done and samples were&#x0D; inoculated on Sabouraud’s dextrose agar (SDA). Growth obtained was analyzed as&#x0D; per standard protocol. &#x0D; &#x0D; Results: GM assay positivity&#x0D; among suspected patients of IA was 47%. The mean age group affected was 51.8&#x0D; years (51.8±15.2) and majority was males (78.1%). The patients were categorized&#x0D; as Proven IA (0%), Probable IA (52.7%), Possible IA (41.4%) and No IA (5.9%). Aspergillus flavus was the most common&#x0D; isolate (77.4%) &#x0D; &#x0D; Conclusion: The study&#x0D; demonstrated that serological tests have an edge over routine smear and culture&#x0D; for the diagnosis of invasive aspergillosis. Thus, Galactomannan assay is a&#x0D; useful diagnostic for early detection of IA in high risk patients. J Microbiol Infect Dis 2018; 8(1):8-12

Comparison of real-time PCR, nested PCR, and galactomannan antigen detection by enzyme-linked immunosorbent assay in sera for diagnosis of invasive aspergillosis

Conventional methods for diagnosis of invasive aspergillosis (IA) lack sensitivity and specificity. Serological methods still have many cases of cross-reactivity. However, molecular techniques seem to arise as a rapid approach, specific and direct that could be used in the diagnosis of IA. In this study, we analyzed 88serum samples from patients of having IA using GM-ELISA test, nested PCR with primers for the rRNA 18S of Aspergillus genus and real time PCR specific for A.fumigatus. Among the 88samples, 64of them had positive GM titers and 23had positive nested PCRs; 18of the 23PCR-positive samples were also GM-positive. On the other hand, 18samples were detected positive by reel time PCR; 13positive samples were also detecting positive by nested PCR. QPCR revealed 26% of the patients with IA, while nested PCR and galactomannan ELISA revealed respectively 34% and 94% of the patients with IA. Probable IA was diagnosed in 18and possible IA was diagnosed in 6episodes. Forty-four episodes were defined as not having IA. The positive and negative predictive values were respectively 100%, and 88% for QPCR, 100% and 97% for nested PCR, and 28% and 60% for GM test. These results suggesting that combined use of methods might improve the diagnosis of IA.

A prospective study of fungal biomarkers to improve management of invasive fungal diseases in a mixed specialty critical care unit

PurposeThe diagnosis of invasive fungal diseases (IFD) in critical care patients (CrCP) is difficult. The study investigated the performance of a set of biomarkers for diagnosis of IFD in a mixed specialty critical care unit (CrCU). MethodsA prospective observational study in patients receiving critical care for ≥7days was performed. Serum samples were tested for the presence of: (1-3) - β-d-glucan (BDG), galactomannan (GM), and Aspergillus fumigatus DNA. GM antigen detection was also performed on bronchoalveolar lavage (BAL) samples. The patients were classified using published definitions for IFD and a diagnostic algorithm for invasive pulmonary aspergillosis. Performance parameters of the assays were determined. ResultsIn patients with proven and probable IFD, the sensitivity, specificity, PPV and NPV of a single positive BDG were 63%, 83%, 65% and 83% respectively. Specificity increased to 86% with 2 consecutive positive results. The mean BDG value of patients with proven and probable IFD was significantly higher compared to those with fungal colonization and no IFD (p value<0.0001). ConclusionNew diagnostic criteria which incorporate these biomarkers, in particular BDG, and host factors unique to critical care patients should enhance diagnosis of IFD and positively impact antifungal stewardship programs.

Fungal Opportunistic Pneumonias in HIV/AIDS Patients: An Indian Tertiary Care Experience.

Opportunistic pneumonias are a major cause of mortality and morbidity in Human Immunodeficiency Virus (HIV) reactive patients. Despite the significant role that fungi play in causation of this opportunistic mycoses, very few Indian studies have attempted to investigate the burden and aetiological spectrum of HIV/AIDS-associated fungal pneumonias. To document the prevalence of fungal aetiology in HIV/AIDS-related opportunistic pneumonias in an Indian setting; and to elucidate the various fungal opportunists responsible for the same. The present study was a prospective, cross-sectional analysis conducted at Maulana Azad Medical College and associated Lok Nayak Hospital, New Delhi from October 2008 to September 2011. Expectorated sputa were collected from 71 HIV reactive patients with a clinical diagnosis of pneumonia and subjected to direct microscopic examination employing Gram stain, 10% KOH wet mount and India ink preparation. In addition, direct immunofluorescence of sputum samples was performed for detection of cysts and trophozoites of Pneumocystis carinii. Also, each sputum sample was inoculated in duplicate onto Sabouraud Dextrose Agar (SDA) for culture. A blood sample was drawn from each patient and a battery of serological tests was performed, including Cryptococcal Antigen Latex Agglutination System (CALASTM) for detection of cryptococcal capsular polysaccharide antigen; Platelia™ Aspergillus EIA for detection of Aspergillus galactomannan antigen; SERION ELISA antigenCandida for detection of Candida antigen and Histoplasma DxSelect™ for detecting antibodies to Histoplasma species. Descriptive statistics were employed to depict results as proportions and figures. Further, arithmetic mean and standard deviation were calculated for central tendencies and median for non-normal/skewed distributions. A definite fungal aetiology was established in 25 (35.2%) of 71 HIV reactive patients with pneumonic involvement. Of these, sputa of 21 patients yielded single fungal isolates, while mixed fungal isolates were reported in four patients. Pneumocystis carinii was the predominant fungal pathogen isolated in our study and was reported in 14 (19.7%) patients. Pulmonary aspergillosis was reported in 7 (9.9%) patients, with Aspergillus flavus (4), Aspergillus fumigatus (2) and Aspergillus niger (1) being the commonly recovered Aspergillus species. Candida pneumonia was documented in 6 (8.5%) patients and the Candida species isolated included Candida albicans in four, Candida glabrata in one and Candida tropicalis in one of these six patients respectively. Pulmonary cryptococcosis was diagnosed in 2 (2.8%) patients; a coexisting cryptococcal meningitis was documented in one of them. Furthermore, antibodies against Histoplasma species were detected in 21 (29.6%) cases suggesting its possible aetiological role. Fungal opportunistic pneumonias are common in HIV reactive patients in Indian setting and warrant a prompt and accurate diagnostic evaluation in the form of a combination of microbiological, serological and histopathological techniques, for an effective prophylactic and therapeutic management.

Detection of Galactomannan Antigen in the Serum of Iraqi Patients with Suspected Invasive Aspergillosis

Invasive aspergillosis is a severe infection that occurs in patients with prolonged neutropenia, following chemotherapy,transplantation,or immunosuppressive protocols .Galactomannan ( GM) is a molecule ,found in the cell wall of Aspergillus species and is released in the blood during growth .The detection of GM in the blood is used to diagnose the invasive Aspergillosis in humans using ELISA assay.Objectives: To detect Galactomannan antigen in in the serum of immunocompramized patients suspected to have invasive aspergillosis.Patients and methods: This study was conducted on 50 patients from the hematology&amp;oncology department,of Baghdad teaching hospital and pediatric oncology wards ,from March 2013 to October 2013.The patients presented with fever that is not responding to antibiotics along with cough and sputum and abnormal chest X-ray findings suspicious of IA. 11 healthy Iraqi individuals served as a control group.Results: ELISA test was positive in 39 of 50 (78%)while all of the control group individuals were negative(100%).The concentration of galactomannan antigen detected by ELISA was statistically significant when compared to control group( OD 0.658±0.033 vs 0.191±0.020 respectively) ( p&lt;0.05).Conclusion: The detection of galactomannan antigen is a very useful and rapid method for the diagnosis of invasive aspergillosis disease in immunocompromised patients.

دور بروتين الكالاكتومانان في تشخيص حالات الاصابه بفطريات الرشاشيات في حالات ذات الرئه لمرضى ردهات امراض الدم

الخلفيه :تمثل فطريات الرشاشيات نوع من الفطريات الرميه الا انها تصيب مرضى الامراض السرطانيه ذوي المناعه المتدنيه با.صابات خطيره جدا مثل ذات الرئه وامراض الفطريات الاختراقيه ةلا يمكن تشخيصها الا في وقت متاخر مما قد يسبب الوفاه لذالك وجد فحص الكالاكتومانان لتسريع وتسهيل التشخيص وبدرجه عاليه من الدقه الاهداف:تهدف الدراسه لبيان دور الاجسام المضاده لبروتين الكالاكتومانان في تشخيض فطر الاسبرجلس فيوميكاتوس بواسطه فحص الايلايزالعينات الدم طرق العمل: شملت الدراسه خمسون مريضا واربع وستون عينه من الدم لمرضى ردهات امراض الدم السرطانيه وردهات سرطان الاطفال للفتره من اذار الى تشرين اول عام2013,و من لمرضى يعانون من سعال وهبوط مستوى كريات الدم العدله ولا تستجيب للعلاج بالمضادات الحيويه النتائج:كانت النتائج تسجل نسبه 78%من مرضى المتوقع اصابتهم بامراض الرشاشيات كانت اصاباتهم موجبه لفحض مضادات الكالاكتومانان بينما كانت حالات المقارنه 100%سلبيه الاستنتاج:يمثل فحص مضادات البروتين كالاكتومانان بواسطه الايلايزا وسيله سهله وسريعه وذات دقه عاليه في تشخيص الاصابات الفطريه المحتمله لمرضى امراض الدم وذوي المناعه المنخفضه