Hospital Trichosporon asahii isolates with simple architecture biofilms and high resistance to antifungals routinely used in clinical practice.

Infections by Trichosporon spp. are increasing worldwide and its treatment remains a challenge. Colonization of medical devices has been considered as a predisposing factor for trichosporonosis, which is related to fungal biofilm production. Thus, this study aimed to evaluate the ability of six hospital T. asahii isolates to form biofilm on abiotic surface, as well as to investigate the impact of three classic antifungals on both planktonic and biofilm forms. The fungal identification was based on macro and micromorphological characteristics, biochemical tests and confirmation by mass spectrometry assisted by the flight time desorption/ionization matrix (MALDI-TOF MS). Antifungal susceptibility assay of planktonic cells showed inhibitory and fungicidal concentrations ranging from 2.5 to 10 µg/mL for voriconazole, 2 to 8 µg/mL for fluconazole, and 1 to 4 µg/mL for amphotericin B. All T. asahii strains were able to form biofilms on the polystyrene microplates surface within 24 h, showing a simple architecture when compared with Candida spp. biofilm. On the other hand, the same antifungals did not show action in neither the inhibition of biofilm formation nor on the formed biofilm. Concluding, the present study reinforced the relevance of the MALDI-TOF MS methodology for a safe identification of T. asahii. Classic antifungals were active on the planktonic form, but not on the biofilms. All isolates formed biofilms on the polystyrene microplates and showed a simple architecture.

Rhodotorula sp. and Trichosporon sp. are more Virulent After a Mixed Biofilm.

Rhodotorula spp. and Trichosporon spp. are opportunistic pathogens, and although an association between these two species in the same infection appears to be uncommon, it has been reported. This is the first study that aimed to evaluate the pathogenesis of a co-infection by R. mucilaginosa and T. asahii, using a new in vivo model, the Zophobas morio larvae. Suspensions from planktonic and biofilm-recovered cells were injected in the larvae as in monospecies as mixed (a ratio of 1:1 for both agents of a of 105 inoculum). Individual and mixed biofilms of R. mucilaginosa and T. asahii were produced for 24 and 48 h, and they were partially characterized by crystal violet and reduction of tetrazolium salt. When evaluating the impact of the planktonic suspension in vivo we verified that the fungi in monoculture were more able to kill the larvae than those from planktonic mixed suspension. On the other hand, regarding biofilm-recovered cells, there was an increase in the death of larvae infected for mixed suspensions. Moreover, the death rate was more pronounced when the larvae were infected with 48 h biofilm-recovered cells than the 24 h ones. T. asahii was the best producer of total biomass, mainly in 48 h. The metabolic activity for both yeasts organized in biofilm maintained the same pattern between 24 and 48 h. The present study proves a synergistic interaction between R. mucilaginosa and T. asahii after an experience in a mixed biofilm. Our results suggest that both species were benefited from this interaction, acquiring a greater potential for virulence after passing through the biofilm and this ability was acquired by the cells released from the biofilm.

Performance of Two Extracts Derived from Propolis on Mature Biofilm Produced by Candida albicans.

Species of the Candida genus represent the third most common cause of onychomycosis, the most frequent and difficult to treat nail infection. Onychomycosis has been attributed to fungi organized in biofilm and some natural products have proved promising for its treatment. This study aimed to evaluate the antibiofilm activity of propolis extract (PE) and its by-product (WPE) on 7-day preformed biofilms produced by Candida albicans in polystyrene microplates, as well as in an ex vivo model on human nail fragments. The cytotoxicity and permeation capacity were also assessed. Firstly, multiple parameters were evaluated over 7 days to elucidate the dynamics of biofilm formation by C. albicans. The cell viability and total biomass did not vary much from the beginning; however, days 3 and 4 were crucial in terms of metabolic activity, which was significantly increased, and the levels of extracellular matrix components, wherein proteins and nucleic acids experienced an increase, but polysaccharide levels dropped. Architecturally, one-day biofilm showed a monolayer of organized cells (blastoconidia, hyphae, and pseudohyphae), while in the seven-day biofilm there was a three-dimensional well-structured and complex biofilm. This yeast was also able to form a biofilm on both surfaces of the nail, without an additional nutritional source. Both extracts showed excellent antibiofilm activity against the 7-day preformed biofilm and were not toxic to Vero cells at concentrations compatible with the antifungal and antibiofilm activities. Both extracts permeated the experimentally infected nail, with WPE being more efficient. The results of this study, taken together, reinforce the potential of these natural products, containing propolis, as a safe option for the topical treatment of onychomycosis.

pH interferes in photoinhibitory activity of curcumin nanoencapsulated with pluronic® P123 against Staphylococcus aureus.

Microbial contamination control is a public health concern and challenge for the food industry. Antimicrobial technologies employing natural agents may be useful in the food industry for these purposes. This work aimed to investigate the effect of photodynamic inactivation using curcumin in Pluronic® P123 nanoparticles (Cur/P123) at different pH and blue LED light against Staphylococcus aureus. Bacterial photoinactivation was conducted using different photosensitizer concentrations and exposure times at pH 5.0, 7.2 and 9.0. A mixture design was applied to evaluate the effects of exposure time (dark and light incubation) on the photoinhibitory effect. S. aureus was completely inactivated at pH 5.0 by combining low concentrations of Cur/P123 (7.80-30.25 µmol/L) and light doses (6.50-37.74 J/cm2). According to the mathematical model, dark incubation had low significance in bacterial inactivation at pH 5.0 and 9.0. No effect in bacterial inactivation was observed at pH 7.2. Cur/P123 with blue LED was effective in inactivating S. aureus. The antimicrobial effect of photodynamic inactivation was also pH-dependent.

Hypericin-mediated photoinactivation of polymeric nanoparticles against Staphylococcus aureus.

Photoinactivation is a promising technique for Staphylococcus aureus control. This microorganism causes foodborne diseases (DTAs) and forms biofilms that are highly resistant and difficult to eradicate. Thus, the aim of this study was to evaluate the photodynamic activity of hypericin (HYP) in polymeric nanoparticles (Pluronic® P123) against S. aureus planktonic and biofilm cells. Planktonic cells and biofilms of S. aureus (ATCC 25923) were subjected to photoinactivation using low-power orange LED (0.3 mW/cm²) with different HYP formulation concentrations in Pluronic® P123. The P123 molar ratios were 2.5 (HYP/P123-2.5) and 10 (HYP/P123-10), respectively. The treatment times for planktonic cells were proposed by a mixture design, and bacterial photoinactivation was observed in concentrations of 12.5 to 3.12 µmol/L for HYP/P123-2.5 and reductions of ∼ 4.0 log CFU/mL in 12.5 to 0.78 µmol/L for HYP/P123-10. For biofilms, 30 min of darkness and 30 min of illumination were used. Maximum reductions were similar for both formulations and corresponded to approximately 0.9 log CFU/cm². It was concluded that photoinactivation with longer lighting times was effective against planktonic cells and could be potentially applied to control S. aureus.

Prevalência dos genótipos do vírus da hepatite C na macrorregião noroeste do estado do Paraná, Brasil / Prevalence of genot ypes of hepatitis C virus in the north-western macro-region of the state of Paraná, Brazil

A prevalência da hepatite C apresenta elevada amplitude devido a grande diferenciação genotípica. Neste estudo, foi possível verificar os genótipos do HCV em portadores de hepatite C crônica na macrorregião noroeste do Paraná. Trata-se de um estudo de corte transversal, no qual foram levantados os dados laboratoriais dos pacientes atendidos em um laboratório de análises clínicas de agosto de 2013 a outubro de 2015. Além de verificar a distribuição dos pacientes portadores crônicos do HCV quanto ao sexo e faixa etária, também a distribuição geográfica dos genótipos do HCV de acordo com a área de abrangência de atendimento do laboratório; os resultados foram comparados aos da literatura. Das 348 amostras, 210 (60,3%) eram do genótipo 1 (p < 0,05), 101 (29,0%) do 3 (p < 0,05), 21 (6,0%) do 2, 1 (0,3%) do 4, 1 (0,3%) do 5 e 12 (3,4%) de indeterminados. Das cidades estudadas, as que apresentaram maior detecção de hepatite C foram: Maringá (112 casos/32,2%), Cascavel (59 casos/17,0%), Paranavaí (37 casos/10,6%) e Umuarama (22 casos /6,3%). Sendo assim, os genótipos mais prevalentes foram 1, 3 e 2. Os homens foram os mais afetados e a faixa etária de maior detecção foi entre 40 a 50 anos.

The prevalence of hepatitis C is wide due to great differentiation of genotypes. Current study verifies HCV genotypes in patients with chronic Hepatitis C in the northwestern microregion of the state of Paraná, Brazil. Current transversal study analyzed laboratory data of patients attended to in a clinical test laboratory between August 2013 and October 2015. Study verified the distribution of patients suffering from chronic HCV according to gender and age bracket and to the laboratory attendance range. Results were compared with those in the literature. Results showed that 210 (60.3%) out of 348 samples belonged to genotype 1 (p<0.05), 101 (29.0%) to 3 (p<0.05), 21 (6.0%) to 2, 1 (0.3%) to 4, 1 (0.3%) to 5 and 12 (3.4%) undetermined. The cities with the highest detection of Hepatitis C were: Maringá (112 cases/32.2%), Cascavel (59 cases/17.0%), Paranavaí (37 cases/10.6%) and Umuarama (22 cases /6.3%). Most prevalent genotypes were 1, 3 and 2, with males as the most affected and the greatest occurrence was featured within age bracket 40 ­ 50 years.