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Candida tropicalis is an emerging virulent species. The aim of this study is to determine the biofilm-forming ability of 29 strains of C. tropicalis isolated from inpatients, and to examine its relation with other virulence factors such as cellular surface hydrophobicity (CSH), immediate (15 min, IA) and late (24 h, LA) plastic adherence and filamentation ability. The study was performed in parallel using two incubation temperatures - 37 and 22 °C - to determine the effect of growth temperature variations on these pathogenic attributes of C. tropicalis. Biofilm formation (BF) was measured by optical density (OD) and by XTT reduction (XTT); Slime index (SI), which includes growth as a correction factor in BF, was calculated in both methods. All strains were hydrophobic and adherent - at 15 min and 24 h - at both temperatures, with higher values for 22 °C; the adhered basal yeast layer appears to be necessary to achieve subsequent development of biofilm. Filamentation ability varied from 76.2% of strains at 37 °C to 26.6% at 22 °C. All C. tropicalis strains were biofilm producers, with similar results obtained using OD determination and XTT measurement to evaluation methods; SI is useful when good growth is not presented. BF at 37 °C was similar at 24 h and 96 h incubation; conversely, at 22 °C, the highest number of biofilm-producing strains was detected at 96 h. CSH is an important pathogenic factor which is involved in adherence, is influenced by the filamentation of yeast, and plays a critical role in BF. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A correlation between mucosal colonization by Candida albicans and the subsequent development of invasive respiratory infection has been previously described. The aim of this study was to evaluate different enzymatic activities in vitro and to determine the capacity to form biofilms by 17 C. albicans isolates from bronchial aspirates of mechanically ventilated patients hospitalized in intensive care units. All the C. albicans clinical isolates tested were biofilm producers and displayed detectable levels of proteinase and hemolytic activities, although phospholipase activity was not detected in one strain. The correlation noted among the virulence factors studied suggests that the presence of more than one concurrent factor could facilitate the spread of infection. [ABSTRACT FROM AUTHOR]

Secretion of hydrolytic enzymes is considered a virulence factor in Candida spp. Extracellular enzymatic activities in 29 clinical isolates of Candida tropicalis were analyzed by plate assays. C. tropicalis, similar to Candida albicans, showed elevated hemolytic and esterase activities. However, unlike C. albicans, low aspartyl protease and very low phospholipase activities were detected in C. tropicalis isolates. [ABSTRACT FROM AUTHOR]

The influence of various concentrations (0.003-8 mg/mL) of N-acetylcysteine on the formation of biofilms by 15 strains of Staphylococcus epidermidis has been studied. A dose-related decrease in biofilm formation was observed, except with the lowest concentrations. The 'slime' index relative to the control was 63%, 55%, 46%, 34%, 26% and 26% in the presence of 0.25, 0.5, 1, 2, 4, and 8 mg/mL of N-acetylcysteine, respectively. These data are statistically significant. The inhibitory effect of 2 mg/mL of N-acetylcysteine on slime formation was also verified by electron microscopy. [ABSTRACT FROM AUTHOR]

The influence of various incubation atmospheres on the growth and slime production of 23 Staphylococcus epidermidis strains was studied. The atmospheres evaluated were aerobiosis (control), anaerobiosis, candle jar, 5 % CO and 10 % CO. As compared to the aerobic control, growth was 55.7 ± 19 % (p<0.01) in anaerobic incubation, 113.7 ± 12 % (p<0.01) in 5 % CO, 112.8 ± 13 % (p<0.01) in 10 % CO and 106.4 ± 7 % (p>0.1) in the candle jar. The slime production in relation to the aerobic control was 20.3 ± 19 % in anaerobiosis (p<0.01), 22.3 ± 27 % (p<0.01) in 5 % CO, 29.4 ± 39 % (p<0.01) in 10 % CO and 68.3 ± 26 % (p>0.1) in the candle jar. The results of this study may explain the discrepancies which have been noted on occasion between slime formation data and pathogenicity. [ABSTRACT FROM AUTHOR]

Myiasis is the term used to describe infestations, both obligatory and accidental, in vertebrate animals and humans by dipteral larvae. The oral cavity is rarely affected by this infestation and the circumstances which can lead to oral myiasis include persistent mouth opening together with poor hygiene, or facial traumatism. We present a case of oral myiasis by larvae of Lucilia sericata, a species present in the Iberian Peninsula, in a hospitalized patient with surgical problems. [ABSTRACT FROM AUTHOR]

Several studies exist on the hydrophobicity of different strains of Candida albicans, but little is known about the hydrophobic characteristics of Candida parapsilosis, despite the fact that this species is becoming an important pathogen. This study shows that a large number of strains of C. parapsilosis do not exhibit the general hydrophobic behaviour of other species of candida under the same incubation temperatures. Various experimental assays were employed to discern the hydrophobic characteristics of the different strains studied. Adhesion to p-xylene did not present differences between the high hydrophobicity of C. parapsilosis 294 cultured at 22 and 37 °C (the percentage of adhesion to p-xylene was near to 100% in both cases), while water contact angle showed this strain to be more hydrophobic at the highest growth temperature (&thetav;W(37 °C)=50°; &thetav;W(22 °C)=38°) with a good correlation to the increase of the adhesion to hexadecane and chloroform in this case. These methods revealed the same hydrophilic character of C. parapsilosis 289 (&thetav;W(37 °C)=22°; &thetav;W(22 °C)=26°), and this was also reflected in the low adhesion to both solvents. A thermodynamical analysis based on interfacial interaction free energies was applied to the adhesion of yeasts to hexadecane and chloroform. The relative intensity of the yeast–water–solvent interaction free energy against solvent–water–solvent interaction free energy is presented as a useful relation to predict the adherence of the cells, and gave good results for the most hydrophobic strain 294 at both culture temperatures. [Copyright &y& Elsevier]

Staphylococcus epidermis has emerged as the main causative agent of medical device-related infections. Their major pathogenicity factor lies in its ability to adhere to surfaces and proliferate into biofilms, which increase their resistance to antibiotics. The main objective of this study was to evaluate the use and the mechanism of action of an ethanolic extract of Spanish propolis (EESP) as a potential alternative for preventing biofilm-related infections caused by S. epidermidis . The chemical composition of propolis is reported and its antibacterial activity against several strains of S. epidermidis with different biofilm-forming capacities evaluated. The influence of sub-inhibitory concentrations (sub-MICs) of EESP on their growth, physicochemical surface properties, adherence, and biofilm formation were studied. EESP interferes with planktonic cells, homogenizing their physicochemical surface properties and introducing a significant delay in their growth. The adherence and biofilms at the EESP concentrations investigated were decreased up to 90.5% among the strains. Microscopic analysis indicated that the planktonic cells that survived the treatment were the ones that adhere and proliferate on the surfaces. The results obtained suggest that the EESP has a high potential to be used as an inhibitor of both the adhesion and biofilm formation of S. epidermidis.