Comparison of amphotericin B lipid complex, deoxycholate amphotericin B, fluconazole, and anidulafungin activity against Candida albicans biofilm isolated from breakthrough candidemia

INTRODUCTION

Biofilm formation causes virulence and resistance in Candida albicans. However, little is known about breakthrough candidemia isolates. We evaluated the antifungal activity of fluconazole, anidulafungin, deoxycholate amphotericin B (dAMB), and amphotericin B lipid complex (ABLC) against biofilms of C. albicans isolated from patients with breakthrough candidemia.

METHODS

The present study used strains of C. albicans isolated from breakthrough and non-breakthrough candidemia patients (control group). The susceptibility of planktonic cells to amphotericin B, anidulafungin, and fluconazole was determined by broth microdilution. Antifungal activity in sessile cells was evaluated using the minimum biofilm eradication concentration (MBEC), metabolic activity was estimated by reducing MTT, and biomass was estimated using crystal violet retention.

RESULTS

The planktonic strains were susceptible to amphotericin B, anidulafungin, and fluconazole, with minimum inhibitory concentrations of 1, ≤0.03, and 2mg/L, respectively. However, fluconazole and anidulafungin did not exert an antifungal effect on biofilms. Additionally, dAMB and ABCL reduced the metabolic activity and biomass. However, eradication was only achieved using 16mg/L dAMB. C. albicans isolates of breakthrough candidemia exhibited strong biofilm production, and the in vitro activity of available therapeutic options was poor.

CONCLUSION

In the present study, only dAMB and ABCL exhibited antibiofilm effects against sessile breakthrough candidemia isolates.

Evaluation of Staphylococcus aureus and Candida albicans biofilms adherence to PEEK and titanium-alloy prosthetic spine devices

BACKGROUND

Titanium and polyether-ether-ketone (PEEK) interbody cages are commonly used for spine fusion. Few data are known about bacterial and yeast biofilms formation in these implants. The aim of this study was to compare Staphylococcus aureus and Candida albicans biofilm formation in the surface of two different interbody devices used routinely in spine surgery.

METHODS

Six bodies of proof specimens of PEEK and titanium alloy were used for microbiological tests, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Experimental biofilm was produced with Staphylococcus aureus and Candida albicans, followed by quantitative analysis of planktonic cells and sessile cells. The comparison between the medians of biofilm quantification between the two models was performed using the Mann-Whitney test and considered the statistical difference for a p < 0.05.

RESULTS

In the S. aureus model, in both planktonic and sessile cell counts, titanium-alloy samples showed lower values for colony forming units per milliliter (UFC/mL) (p < 0.05). The evaluation through the optic density of planktonic and sessile cells showed lower values in the titanium-alloy samples, however, only statistically significant in planktonic cell count (p < 0.05). The count of planktonic yeast cells in PEEK was similar to titanium-alloy samples, while the count of sessile yeast cells in titanium alloy was lower when compared to PEEK (p < 0.05).

CONCLUSION

Titanium-alloy models were associated with less staphylococcal and Candida biofilm formation when compared with PEEK.

p27kip1 as a key regulator of endometriosis

p27^kip1 as a key regulator of endometriosis Gonçalves GA p27^kip1 is a cyclin-dependent kinase (CDK) inhibitor whose specific late G1 destruction allows progression of the cell across the G1/S boundary. There is a direct relationship between low level of p27 and rapid proliferation occurring in several benign states and in many malignances. In the glandular cells of the normal endometrium, the level of p27^kip1 is exceedingly low during the proliferative phase, whereas it is markedly increased during the secretory phase. The expression of p27^kip1 in endometriosis is very low but has been found to increase following treatment with progesterone. However, estrogen exposure is considered as a major risk factor in developing endometrial cancer. Endometriosis endometrial cells cultures have also lower levels of p27^kip1 compared to heath endometrial cells cultures and restore the cell cycle balance when transduced with an adenoviral vector carring the p27^kip1 coding gene (Adp27EGFP). More uniform and rigorous studies are required to confirm these and additional markers utility in a diagnostic and possible treatment panel. As a major clinical priority is to determine which lesions can be treated medically and which require surgical intervention, focusing future studies on markers that distinguish response to hormone therapy or are involved in hormone regulation, will be important future considerations. The goal of this highlight review is to provide a broad overview of the advancements in studies about endometriosis mainly correlating the cytokine p27^kip1 expression with the diagnostic and disease treatment.

A tank-to-wheel analysis tool for energy and emissions studies in road vehicles

Currently, oil based fuels are the primary energy source of road transport. The growing need for oil independence and CO(2) mitigation has lead to the increasing importance of alternative fuel usage. CO(2) is produced not only as the fuel is used in the vehicle (tank-to-wheel contribution), but also upstream, from the fuel extraction to the refueling station (well-to-tank contribution), and the life cycle of the fuel production (well-to-wheel contribution) must be considered in order to analyse the global impact of the fuel utilization. A road vehicle tank-to-wheel analysis tool that may be integrated with well-to-tank models was developed in the present study. The integration in a demonstration case study allowed to perform a life cycle assessment concerning the utilization of diesel and natural gas fuels in a specific network line of a bus transit company operating in the city of Porto, Portugal.