Surface modification of poly(methyl-methacrylate) with farnesol to prevent Candida biofilm formation

Candida albicans promotes biofilm formation on dentures, which compromises the use of poly(methyl-methacrylate) (PMMA) as a dental material. Farnesol (FAR), a natural compound that prevents C. albicans filamentation and biofilm formation, was incorporated into the PMMA matrix, to obtain antifungal PMMA_FAR materials. The tested concentrations (0·0125% and 0·4%) of FAR, 24 h after incubation on YPD agar, inhibited filamentation of C. albicans. PMMA was modified with different FAR concentrations (3-12%), and physicochemical properties, antifungal activity and cytotoxicity of these modified materials (PMMA_FAR) were tested. The presence of FAR in PMMA_FAR composites was verified by Fourier-transform infrared spectroscopy (FT-IR). Incorporation of FAR into the polymeric matrix significantly decreased hydrophilicity at all tested concentrations and significantly reduced biofilm and planktonic cells metabolic activity in the early stage of biofilm formation at ≥6% FAR in PMMA. PMMA_FAR composites with <9% FAR were non-toxic. Modification of PMMA with FAR is a good strategy for reducing C. albicans biofilm formation on dentures.

Seroepidemiological Study of Canine and Human Dirofilariasis in the Endemic Region of Northern Serbia

Dirofilariasis is a vector-borne zoonotic disease caused mainly by Dirofilaria immitis and Dirofilaria repens that affect dogs and humans all over the world. Serbia is considered an endemic country to both forms of dirofilariasis, although most of the population is concentrated in the north of the country. The aims of this study were to show the prevalence of D. immitis and D. repens in dogs and the seroprevalence in humans compared to previous studies in Northern Serbia. In total, 346 dog sera samples and 265 human samples were analyzed. Dog blood samples were analyzed using the modified Knott's method to check whether there were Dirofilaria spp. microfilariae and serum samples were checked by a commercial D. immitis antigen test. Human serum samples were analyzed with a non-commercial ELISA for detection of specific anti-D. immitis, anti-D. repens, and anti-Wolbachia IgG antibodies, and confirmed by western blotting. The overall prevalence for Dirofilaria spp. in dogs was 29.19%. The overall prevalence for D. immitis was 26.30%. The percentages of D. immitis and D. repens microfilaremia in dogs were 25.72 and 1.45%, respectively, while D. immitis./D. repens microfilaremia co-infections were also 1.45%. The overall seroprevalence for Dirofilaria spp. in humans was 3.77%. The overall seroprevalence for D. immitis was 1.51, 1.13% for D. repens, and for D. immitis/D. repens co-infections was 1.13%. The results indicate that D. immitis and D. repens are present in dogs and humans in the province of Vojvodina, in the northern part of Serbia. It is most likely associated with the presence of many rivers, the climate, and presence of mosquitoes in the area, so there could be a real public health risk.

Diagnosis of Pneumocystis jirovecii Pneumonia in Pediatric Patients in Serbia, Greece, and Romania. Current Status and Challenges for Collaboration

Pneumocystis jirovecii can cause fatal Pneumocystis pneumonia (PcP). Many children have been exposed to the fungus and are colonized in early age, while some individuals at high risk for fungal infections may develop PcP, a disease that is difficult to diagnose. Insufficient laboratory availability, lack of knowledge, and local epidemiology gaps make the problem more serious. Traditionally, the diagnosis is based on microscopic visualization of Pneumocystis in respiratory specimens. The molecular diagnosis is important but not widely used. The aim of this study was to collect initial indicative data from Serbia, Greece, and Romania concerning pediatric patients with suspected PcP in order to: find the key underlying diseases, determine current clinical and laboratory practices, and try to propose an integrative future molecular perspective based on regional collaboration. Data were collected by the search of literature and the use of an online questionnaire, filled by relevant scientists specialized in the field. All three countries presented similar clinical practices in terms of PcP prophylaxis and clinical suspicion. In Serbia and Greece the hematology/oncology diseases are the main risks, while in Romania HIV infection is an additional risk. Molecular diagnosis is available only in Greece. PcP seems to be under-diagnosed and regional collaboration in the field of laboratory diagnosis with an emphasis on molecular approaches may help to cover the gaps and improve the practices.

Streptococcus pyogenes as the cause of vulvovaginitis and balanitis in children

BACKGROUND

Streptococcus pyogenes (group A Streptococcus) is the etiological agent of perineal infection in children, consisting of perianal infection, vulvovaginitis and balanitis. If it is not properly diagnosed and treated, it can persist for many months and can cause severe complications. Furthermore, treatment with penicillin can be followed by failures and recurrences.

METHODS

We report here the prevalence of S. pyogenes isolates in genital tract specimens from girls (n = 1692) with symptoms of vulvovaginitis and from boys (n = 52) with balanitis in the municipality of Nis, Southeast-Serbia (the Western Balkans) in a 10 year period, and the seasonal distribution, patient age and sensitivity to bacitracin and antimicrobial drugs used in the treatment of streptococcal infection.

RESULTS

Streptococcal vulvovaginitis was diagnosed in 2.30% of examinees. Of those cases, 64.10% were detected from April to September, and it was most common (71.79%) in girls aged 3-7 years. Streptococcal balanitis was diagnosed in two instances: in a 4-year-old boy and in a 7-year-old boy. S. pyogenes strains resistant to bacitracin were identified in five girls. Two isolates with M phenotype and five isolates with cMLS_B phenotype were identified.

CONCLUSIONS

Streptococcal vulvovaginitis was diagnosed less often in the present study, but it was still far more common than streptococcal balanitis in childhood. Bacitracin resistance of S. pyogenes strains should be taken into account in routine microbiological identification, and the detection of S. pyogenes isolates resistant to erythromycin requires surveillance in the present geographical territory.

Surveillance and characterization of Candida bloodstream infections in a Serbian tertiary care hospital

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.

Alternaria-Associated Fungus Ball of Orbit Nose and Paranasal Sinuses: Case Report of a Rare Clinical Entity

Alternaria-associated fungus ball of maxillar, ethmoidal paranasal sinuses, nasal cavity and orbit with bone erosion is extremely rare. Till recently, only two cases of this infection in immune competitive patients have been reported. We are herein describing the case of immune-competent woman who suffered of nasal congestion for 10 years. Patient was treated for tumor-like lesion in right maxillar sinus, where propagation in right nose cavity, right ethmoidal cells and right orbita was present. The organism that was seen in surgical removal of fungal debris by histological study, in using mycological testing, was proven as Alternaria alternata. Combination of surgical intervention and treatment with itraconazole eradicated fungal infection, and the disease was not relapsed in follow-up period of 2 years.