Valentina Arsic-Arsenijevic

Seroreactivity to Dirofilaria antigens in people from different areas of Serbia

BackgroundThe Northern part of Serbia is hyperendemic-endemic for canine dirofilarioses. Considering this fact, many human dirofilarial infections could be expected, however only about 30 cases in Serbia have been described until today. Aims of this survey were to assess the people reactivity to the antigens of D. repens and D. immitis and to identify risk factors for the contact exposure.MethodsInvestigation included sera taken from 297 people (179 women and 118 men) living in different areas of Serbia (Pančevo, Novi Sad, Zaječar, Leskovac, Vranje, Niš, Pirot). Sera were analysed by means of two indirect enzyme-linked immunosorbent (ELISA) home-designed that use as antigens adult somatic/metabolic polyproteins of D. repens (DR) and D. immitis (DI), respectively. The results were elaborated using the statistical method of descriptive and quantitative analysis.ResultsSignificant differences by area in the reactivity of human sera to dirofilarial antigens were not observed (p = 0.056). A high seroreactivity was demonstrated in people from the towns of northern Serbia (Pančevo = 27,1%; Novi Sad = 16,3%), as well as in people from Zaječar (eastern Serbia = 15,8%) and Vranje (southern Serbia = 15,1%). No differences were evidenced between people reactivity to polyproteins of the two dirofilarial species, nor differences related to the gender of examinees. Factor risks evidenced were: i) place of residence; ii) spending work time outdoors during the mosquito season; iii) spending time outdoors and nearby rivers, lakes, swamps or canals; unespectedly, iv) cat owning.ConclusionThe findings emerging from this investigation indicate that clinicians and public health authorities should pay greater attention to this zoonosis. Continuing education and training of physicians will greatly contribute to the knowledge of the actual impact of filarial worms on animal and public health, and allow for the planning of suitable measures to prevent the infections.

Improving outcome of fungal diseases – Guiding experts and patients towards excellence

Invasive fungal infections are on the rise and during recent years understanding the epidemiology of fungal infections improved. Over 1 billion people are affected and 25 million patients are at imminent risk of severe organ damage or death due to fungal infection. The European Confederation of Medical Mycology (ECMM), founded in 1993, is the roof organisation of 23 National Medical Mycology Societies in Europe. ECMM fights fungal infections at various levels, by creating and distributing scientific knowledge and promoting scientific exchange. In response to the increasing prevalence and management complexity of invasive fungal infections, ECMM recently launched three additional initiatives (https://www.ecmm.info/). (i) ECMM together with other European infectious diseases societies created a comprehensive set of European guidelines for the diagnostic and therapeutic management of invasive fungal infections. (ii) ECMM founded the ECMM Academy awarding fellow status (FECMM) to outstanding researchers who advanced medical mycology. The academy aims at strengthening networking activities between these researchers. (iii) Centres throughout the world can apply for ECMM Excellence Center Status. Following such application on site auditing of up to three levels of mycological work (clinical, microbiological, epidemiological/clinical trials) evaluates the excellence of a centre along predefined criteria. All three initiatives share a common ambition; they aim at improving outcome of fungal diseases through guiding experts and patients towards excellence. Acknowledging fungal infections as a global problem, all three initiatives explicitly reach out beyond European borders.

Proven invasive pulmonary mucormycosis successfully treated with amphotericin B and surgery in patient with acute myeloblastic leukemia: a case report

IntroductionInvasive mucormycosis (zygomycosis) is the third most frequent fungal infection in patients with hematologic malignancies. It often results in a fatal outcome mainly due to the difficulty of early diagnosis and its resistance to antimycotics.Case presentationA 52-year-old Caucasian man was diagnosed with acute myeloblastic leukemia. Following the induction chemotherapy he developed febrile neutropenia. Meropenem (3×1000mg/day) was introduced empirically. A chest computed tomography showed soft-tissue consolidation change in his right upper lobe. A bronchoscopy was performed and the histology indicated invasive pulmonary aspergillosis based on fungal hypha detection. Also, high risk patients are routinely screened for invasive fungal infections using commercially available serological enzyme-linked immunosorbent assay tests: galactomannan and mannan (Bio-Rad, France), as well as anti-Aspergillus immunoglobulin G and/or immunoglobulin M and anti-Candida immunoglobulin G and/or immunoglobulin M antibodies (Virion-Serion, Germany). Galactomannan showed low positivity and voriconazole therapy (2×400mg/first day; 2×300mg/following days) was implemented. The patient became afebrile and a partial remission of disease was established. After 2 months, the patient developed a fever and a chest multi-slice computed tomography showed soft-tissue mass compressing his upper right bronchus. Voriconazole (2×400mg/first day; 2×300mg/following days) was reintroduced and bronchoscopy was repeated. Histologic examination of the new specimen was done, as well as a revision of the earlier samples in the reference laboratory and the diagnosis was switched to invasive pulmonary mucormycosis. The treatment was changed to amphotericin B colloidal dispersion (1×400mg/day). The complete remission of acute myeloblastic leukemia was verified after 2 months. During his immunerestitution, a high positivity of the anti-Aspergillus immunoglobulin M antibodies was found in a single serum sample and pulmonary radiography was unchanged. A lobectomy of his right upper pulmonary lobe was done and the mycology culture of the lung tissue sample revealed Rhizopus oryzae. He remained in complete remission for more than 1 year.ConclusionsInvasive mucormycosis was successfully treated with amphotericin B, surgery and secondary itraconazole prophylaxis. As a rare disease invasive mucormycosis is not well understood by the medical community and therefore an improvement of education about prevention, diagnosis and treatment of invasive mucormycosis is necessary.

Azole-Resistance in Aspergillus terreus and Related Species: An Emerging Problem or a Rare Phenomenon?

Objectives: Invasive mold infections associated with Aspergillus species are a significant cause of mortality in immunocompromised patients. The most frequently occurring aetiological pathogens are members of the Aspergillus section Fumigati followed by members of the section Terrei. The frequency of Aspergillus terreus and related (cryptic) species in clinical specimens, as well as the percentage of azole-resistant strains remains to be studied. Methods: A global set (n = 498) of A. terreus and phenotypically related isolates was molecularly identified (beta-tubulin), tested for antifungal susceptibility against posaconazole, voriconazole, and itraconazole, and resistant phenotypes were correlated with point mutations in the cyp51A gene. Results: The majority of isolates was identified as A. terreus (86.8%), followed by A. citrinoterreus (8.4%), A. hortai (2.6%), A. alabamensis (1.6%), A. neoafricanus (0.2%), and A. floccosus (0.2%). One isolate failed to match a known Aspergillus sp., but was found most closely related to A. alabamensis. According to EUCAST clinical breakpoints azole resistance was detected in 5.4% of all tested isolates, 6.2% of A. terreus sensu stricto (s.s.) were posaconazole-resistant. Posaconazole resistance differed geographically and ranged from 0% in the Czech Republic, Greece, and Turkey to 13.7% in Germany. In contrast, azole resistance among cryptic species was rare 2 out of 66 isolates and was observed only in one A. citrinoterreus and one A. alabamensis isolate. The most affected amino acid position of the Cyp51A gene correlating with the posaconazole resistant phenotype was M217, which was found in the variation M217T and M217V. Conclusions: Aspergillus terreus was most prevalent, followed by A. citrinoterreus. Posaconazole was the most potent drug against A. terreus, but 5.4% of A. terreus sensu stricto showed resistance against this azole. In Austria, Germany, and the United Kingdom posaconazole-resistance in all A. terreus isolates was higher than 10%, resistance against voriconazole was rare and absent for itraconazole.

Susceptibility profile of Candida spp. isolated from humans and dogs with stomatitis to the essential oil of Thymus vulgaris

Candida spp. form a part of human and animal oral cavity flora. However Candida spp. is the main cause of dental related stomatitis in humans and stomatitis in dogs. Stomatitis treatment implies the use of azoles and polyenes to which yeasts build up resistance. The research is directed to the use of natural compounds such as essential oils. The aim of this paper is to define the antifungal activity of thyme oil on 15 clinical strains of Candida spp., isolated from humans and dogs and to determine if there is a difference in susceptibility between human and dog isolates. Sampling in patients with stomatitis was done by swabbing the denture or oral mucosa swab while sampling in dogs was done by swabbing the oral cavity mucosa after stomatitis has been diagnosed. In order to investigate the antifungal activity of thyme oil in vitro, microdilution method was used. Thyme oil expressed antifungal effects on all investigated strains. Also, our data show that the values of minimum fungicide concentration (MFC) and minimum inhibitory concentration (MIC) are lower in human strains. Explanation is that in most cases, stomatitis in humans is asymptomatic and thus not treated, so Candida strains have not developed resistance. On the other hand, stomatitis in dogs is followed by a marked clinical picture and treated is by antimicotics (mostly by azoles), therefore resistant Candida strains are more likely to occur.

First case of visceral Leishmaniosis/HIV Coinfection in niš - southeastern serbia

Visceral leishmaniosis (VL) has emerged as an important opportunistic parasitosis associated with human im- munodeficiency virus (HIV) infection. The aim of this paper is to report the first case of Leishmania/HIV coinfection in a patient from Nis (Southeastern Serbia). Microscopical examination of Giemsa-stained bone marrow (BM) smears show the presence of Leishmania spp. amastigotes based on their morphological characteristics. In spite of the parasitologi- cal finding, the serological test applied gave negative results. Molecular analyses confirmed the infection and allowed us to identify the leishmania species as Leishmania infantum (100% identity). VL/HIV coinfection has important clinical, diagnostic and epidemiological implications. In fact, the failure of serological tests is expected in this condition, and the application of molecular diagnostics to the blood may offer, apart from an easy and non-invasive diagnostic opportunity, the possibility of warning about the risk of possible nosocomial infections.

The dietary modification and treatment of intestinal Candida overgrowth – a pilot study

OBJECTIVE The aim of this study was to evaluate the effectiveness of an alternative treatment in a form of recommended diet modification during and after conventional treatment with antifungals in patients with a chronic form of intestinal Candida overgrowth (ICOG). METHODS The study included patients with ICOG divided in two subgroups: patients treated with nystatin and recommended diet regime (study group-SG) and the patients treated only with nystatin (control group-CG). After treatment, the mycological control examination and follow-up were performed two times: the first one within ten days after the completion of antifungal treatment, and the second one three months after the treatment initialization. RESULTS A total of 120 patients finished the study: 80 from the SG and 40 from the CG. At the first mycological control examination of SG patients stools, we noted satisfactory antifungal and symptomatic effect in 56 out of 80 (70.0%) patients and 29 out of 40 (72.5%) in CG, with no statistically significant difference. However, at the second control stool examination, significantly higher percent (85%) of cured patients was recorded after three months of the recommended diet comparing with CG-17 out of 40 (42.5%). CONCLUSION Results of this pilot study showed that patients who adhered to diet modification during and after treatment with nystatin had better outcomes of ICOG and strongly suggest the need for diet modification in these patients which recommendation could reduce excessive prescription of antifungals.

Non-culture based assays for the detection of fungal pathogens

Abstract Traditional, culture based methods for the diagnosis of fungal infections are still considered as gold standard, but they are time consuming and low sensitive. Therefore, in order to overcome the limitations, many researchers have focused on the development of new immunological and molecular based rapid assays that could enable early diagnosis of infection and accurate identification of fungal pathogens causing superficial and invasive infection. In this brief review, we highlighted the advantages and disadvantages of conventional diagnostic methods and possibility of non-culture based assays in diagnosis of superficial fungal infections and presented the overview on currently available immunochromatographic assays as well as availability of biomarkers detection by immunodiagnostic procedures in prompt and accurate diagnosis of invasive fungal infections. In addition, we presented diagnostic efficiency of currently available molecular panels and researches in this area.

A murine model for study of anticryptococcal activity mediated by cytotoxic immune cells: Role in immunization and human vaccine strategies

NK and T cells play a pivotal role in host defense to Cryptococcus neoformans (C. neoformans) fungus which affects especially hosts with impaired cell mediated immunity. The vaccine against cryptococcosus is not developed yet, thus we established an animal BALB/c mice model to analyze anticryprococcal activity of immune cells. We detected that non-stimulated spleen mononuclear cells (MNC) from non-immunized mice have the capacity to exhibit anticriptococcal activity on the incapsulated C. neoformans strain (ATCC 34873) and this activity can be enhanced by non-adherent cells (NAC). In order to obtained antigen-specific anticryprococcal activity, MNC and NAC were stimulated in vitro with corpuscular (Ag1) or soluble (Ag2) C. neoformans antigen prepared from the acapsular strain Cap67 (ATCC 52817). In vitro stimulation of immune cells with both C. neoformans antigens enhanced the anticryptococcal activity of MNC and NAC. NAC fraction expressed the highest anticryptococcal activity, also in the presence and in the absence of accessory cells (AC). The highest anticryptococcal activity of effector cells was detected after immunization of mice with the same C. neoformans antigens and after additional stimulation of immune cells in vitro with the some antigens. These data demonstrated that growth inhibition of C. neoformans mediated by mice effector cells can be enhanced with corpuscular, as well as soluble antigens. Thus designin an animal model which is simple and reproducible and can be used for further studies and development of immunization strategies against human cryptococcosis.