Browsing by Author "Arsenijević, Valentina Arsić (6507940363)"

Background: Aspergillus fumigatus causes serious infections in humans, and its virulence correlates with hyphal growth, branching and formation of the filamentous mycelium. The filamentous mycelium is a complex structure inconvenient for quantity analysis. In this study, we monitored the branching of A. fumigatus filamentous mycelium in vitro at different points in time in order to assess the complexity degree and develop a dynamic model for the branching complexity. Method: We used fractal analysis of microscopic images (FAMI) to measure the fractal dimensions (D) of the branching complexity within 24 h of incubation. Results: By photographing the filamentous mycelium dynamically and processing the images, the D variation curve of A. fumigatus complexity degree was obtained. We acquired the D variation curve which contained initial exponential period and stationary period of A. fumigatus branching. Further, the obtained data of D was modeled via the logistic model (LM) to develop a dynamic model of A. fumigatus branching for the prediction of the specific growth rate of branching value (0.23 h−1). Conclusions: Developed FAMI and LM models present a simple and non-destructive method of predicting the evolution of branching complexity of A. fumigatus. These models are useful as laboratory measurements for the prediction of hyphal and mycelium development, especially relevant to the pathogenesis study of aspergillosis, as well as pathogenesis of other diseases caused by moulds. © 2018

Background: Aspergillus fumigatus causes serious infections in humans, and its virulence correlates with hyphal growth, branching and formation of the filamentous mycelium. The filamentous mycelium is a complex structure inconvenient for quantity analysis. In this study, we monitored the branching of A. fumigatus filamentous mycelium in vitro at different points in time in order to assess the complexity degree and develop a dynamic model for the branching complexity. Method: We used fractal analysis of microscopic images (FAMI) to measure the fractal dimensions (D) of the branching complexity within 24 h of incubation. Results: By photographing the filamentous mycelium dynamically and processing the images, the D variation curve of A. fumigatus complexity degree was obtained. We acquired the D variation curve which contained initial exponential period and stationary period of A. fumigatus branching. Further, the obtained data of D was modeled via the logistic model (LM) to develop a dynamic model of A. fumigatus branching for the prediction of the specific growth rate of branching value (0.23 h−1). Conclusions: Developed FAMI and LM models present a simple and non-destructive method of predicting the evolution of branching complexity of A. fumigatus. These models are useful as laboratory measurements for the prediction of hyphal and mycelium development, especially relevant to the pathogenesis study of aspergillosis, as well as pathogenesis of other diseases caused by moulds. © 2018

For the first time, we aimed to estimate the burden of serious fungal infections or diseases (SFD) and highlight national epidemiological features in Serbia. Data on population and underlining conditions were extracted from the Statistical Office of the Republic of Serbia, World Bank, the Institute of Public Health of Serbia, the World Health Organization, National reference laboratory for medical mycology, the national registries of Serbian professional societies, and relevant publications. The population structure/inhabitants in 2016 (not including the autonomous region Kosovo & Metohija) was 7,058,322; with 6,041,743 adults (85.6%). The populations at risk (total cases per year) were: HIV infected 2441; acute myeloid leukemia 212; stem cell transplantation 151; solid organ transplants 59; chronic obstructive pulmonary disease 250,302; adult asthmatics 311,806; adult cystic fibrosis 65; pulmonary tuberculosis 898; lung cancer 7260; intensive care unit admissions 19,821; and renal support 520. Annual fungal disease cases estimated are: candidemia 518; invasive aspergillosis 619; Candida peritonitis 187; Pneumocystis jirovecii pneumonia 62; cryptococcosis 5; mucormycosis or fusariosis 23; severe asthma with fungal sensitization 10,393; allergic bronchopulmonary aspergillosis 9094; chronic pulmonary aspergillosis 448, recurrent Candida vaginitis 135,303; oral candidiasis 208,489; esophageal candidiasis 173, fungal keratitis 70; tinea capitis 300; and onychomycosis 342,721. We expect that 156,825 people suffer from serious SFD each year (2221/100,000), and 409 dies annually. Additionally, the prevalence of superficial infections exceeds 1,008,995 cases (14,295/100,000). The first Rhinosporidium outbreak in Europe was associated with Serbian Silver Lake. The plant pathogen Fusarium seems to be emerging in Serbian pediatric haematooncology settings. Candida auris and endemic mycoses have not been observed to date. These general estimates provide a primer for further efforts to study fungal epidemiology in Serbia. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.

For the first time, we aimed to estimate the burden of serious fungal infections or diseases (SFD) and highlight national epidemiological features in Serbia. Data on population and underlining conditions were extracted from the Statistical Office of the Republic of Serbia, World Bank, the Institute of Public Health of Serbia, the World Health Organization, National reference laboratory for medical mycology, the national registries of Serbian professional societies, and relevant publications. The population structure/inhabitants in 2016 (not including the autonomous region Kosovo & Metohija) was 7,058,322; with 6,041,743 adults (85.6%). The populations at risk (total cases per year) were: HIV infected 2441; acute myeloid leukemia 212; stem cell transplantation 151; solid organ transplants 59; chronic obstructive pulmonary disease 250,302; adult asthmatics 311,806; adult cystic fibrosis 65; pulmonary tuberculosis 898; lung cancer 7260; intensive care unit admissions 19,821; and renal support 520. Annual fungal disease cases estimated are: candidemia 518; invasive aspergillosis 619; Candida peritonitis 187; Pneumocystis jirovecii pneumonia 62; cryptococcosis 5; mucormycosis or fusariosis 23; severe asthma with fungal sensitization 10,393; allergic bronchopulmonary aspergillosis 9094; chronic pulmonary aspergillosis 448, recurrent Candida vaginitis 135,303; oral candidiasis 208,489; esophageal candidiasis 173, fungal keratitis 70; tinea capitis 300; and onychomycosis 342,721. We expect that 156,825 people suffer from serious SFD each year (2221/100,000), and 409 dies annually. Additionally, the prevalence of superficial infections exceeds 1,008,995 cases (14,295/100,000). The first Rhinosporidium outbreak in Europe was associated with Serbian Silver Lake. The plant pathogen Fusarium seems to be emerging in Serbian pediatric haematooncology settings. Candida auris and endemic mycoses have not been observed to date. These general estimates provide a primer for further efforts to study fungal epidemiology in Serbia. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.

Introduction Acute leukemias treatment requires strong chemotherapy. Patients that develop bone marrow aplasia become immunocompromised, thus becoming liable to bacterial and fungal infections. Fungal infections caused by Candida are frequent. Hepatosplenic candidiasis (HSC) is a frequent consequence of invasive candidiasis which is clinically presented with prolonged febrility unresponsive to antibiotics. Case Outline A 53-year-old patient with acute myeloid leukemia was submitted to standard chemotherapy “3+7” regimen (daunoblastine 80 mg i.v. on days 1 to 3, cytarabine 2×170 mg i.v. during 7 days) and achieved complete remission. However, during remission he developed febrility unresponsive to antibiotics. Computerised tomography (CT) of the abdomen showed multiple hypodense lesions within the liver and spleen. Haemocultures on fungi were negative. However, seroconversion of biomarkers for invasive fungal infection (IFI) (Candida and Aspergillus antigen/Ag and antibody/Ab) indicated possible HSC. Only high positivity of anti-Candida IgG antibodies, positivity of mannan and CT finding we regarded sufficient for the diagnosis and antimycotic therapy. Three months of treatment with different antimycotics were necessary for complete disappearance of both clinical symptoms and CT findings. Conclusion In patients with prolonged febrile neutropenia IFI has to be strongly suspected. If imaging techniques show multiple hypodense lesions within liver and spleen, HSC has to be taken seriously into consideration. We believe that, along with CT finding, positive laboratory Candida biomarkers (mannan and IgG antibodies) should be considered sufficient for “probable HSC” and commencement of antifungal therapy, which must be long enough, i.e. until complete disappearance of clinical symptoms and CT findings are achieved. © 2015, Serbia Medical Society.

Introduction: Candida spp. frequently cause hospital-acquired bloodstream infections (BSI) with a high mortality rate (up to 70%). We analyzed the frequency, infection characteristics, potential predisposing factors, susceptibility to antifungal drugs, biofilm production and other virulence characteristics of Candida spp. isolates obtained from a tertiary care hospital in Niš, Serbia, during a one year period. Methods: Medical histories, characteristics of isolated strains and drug susceptibility, as well as the effect on the function of isolated macrophages and other virulence features were evaluated. The obtained results were subjected to student’s t-test and multivariate statistical analyzes. Results: Herein we report an annual incidence of 3.65 cases of C. albicans, C. lusitaniae and C. lipolytica infections per 105 population. Out of eight isolated strains, two (25%) were shown to be strong biofilm producers, one (12.5%) caused hemolysis on blood agar and in two (25%) cases macrophages were able to completely eliminate the yeast colonies. Chronic kidney disease, diabetes, malignant and other diseases were present in 37.5, 62.5, 50 and 75%, respectively, in the study group. All patients with Candida BSI received antifungal therapy (amphotericin B), however, hospital mortality was observed in 25% of patients. Conclusions: Evaluation of local Candida epidemiology, antifungal susceptibility and virulence factors, as well as personalized patient risk factors are important for the surveillance of Candida BSI, especially in intensive care unit patients and may contribute to the improved options and outcome for patients with Candida BSI. © 2016 Stojanović et al.

Introduction: Candida spp. frequently cause hospital-acquired bloodstream infections (BSI) with a high mortality rate (up to 70%). We analyzed the frequency, infection characteristics, potential predisposing factors, susceptibility to antifungal drugs, biofilm production and other virulence characteristics of Candida spp. isolates obtained from a tertiary care hospital in Niš, Serbia, during a one year period. Methods: Medical histories, characteristics of isolated strains and drug susceptibility, as well as the effect on the function of isolated macrophages and other virulence features were evaluated. The obtained results were subjected to student’s t-test and multivariate statistical analyzes. Results: Herein we report an annual incidence of 3.65 cases of C. albicans, C. lusitaniae and C. lipolytica infections per 105 population. Out of eight isolated strains, two (25%) were shown to be strong biofilm producers, one (12.5%) caused hemolysis on blood agar and in two (25%) cases macrophages were able to completely eliminate the yeast colonies. Chronic kidney disease, diabetes, malignant and other diseases were present in 37.5, 62.5, 50 and 75%, respectively, in the study group. All patients with Candida BSI received antifungal therapy (amphotericin B), however, hospital mortality was observed in 25% of patients. Conclusions: Evaluation of local Candida epidemiology, antifungal susceptibility and virulence factors, as well as personalized patient risk factors are important for the surveillance of Candida BSI, especially in intensive care unit patients and may contribute to the improved options and outcome for patients with Candida BSI. © 2016 Stojanović et al.