RESUMEN
We isolated and identified yeasts from burn wounds and evaluated the ability of Candida parapsilosis isolates from burn wounds to penetrate an acellular dermal matrix (ADM). A prospective study was conducted with patients from the burn treatment center of North Paraná University Hospital in Londrina, Brazil from February 2015 to January 2016. Yeast cultures were obtained from the tissue of burn wounds that had been debrided and cleansed with 2% chlorhexidine. After identification and confirmation of the purity of the culture, the yeasts were placed on ADM fragments and incubated for three or seven days. During the study period, 273 patients were treated, and 36 of these patients fulfilled the inclusion criteria and provided samples for culture. Yeasts were isolated in 19.44% (nâ¯=â¯7) of the cultures, and the following species were identified: C. parapsilosis (57.1%), C. albicans (28.6%), and C. glabrata (14.3%). C. parapsilosis, the most frequent species, was chosen for the ADM tests. We demonstrated active penetration of the ADM by the yeast isolates from burn wounds. C. parapsilosis grew on ADM and penetrated the matrix, indicating that this yeast, which is common in skin and cutaneous wounds, has the potential to colonize and pass through ADM, a medical device that is frequently used to dress and regenerate burn wounds.
Asunto(s)
Dermis Acelular/microbiología , Quemaduras/microbiología , Candida parapsilosis/clasificación , Candida parapsilosis/aislamiento & purificación , Candidiasis/microbiología , Cicatrización de Heridas , Biopelículas/crecimiento & desarrollo , Brasil , Candida/clasificación , Candida/aislamiento & purificación , Candida albicans/aislamiento & purificación , Candida glabrata/aislamiento & purificación , Candida parapsilosis/patogenicidad , Candida parapsilosis/fisiología , Humanos , Estudios Prospectivos , Piel Artificial/microbiologíaRESUMEN
In recent decades, the prognosis for burn patients has improved considerably with the development of specialized care. The acellular dermal matrix (ADM) is a totally artificial acellular device that functions to control water loss, prevent penetration by bacteria and allow migration of endothelial cells and fibroblasts from patient tissues. However, little is known about its effectiveness against yeasts. The present study evaluated the capacity of colonization and migration of some human commensal yeasts. Three clinical isolates from skin scales, identified as Candida parapsilosis, Candida glabrata and Rhodotorula mucilaginosa, were used. Their ability to cross the ADM was evaluated. After three days, all isolates had crossed the ADM. C. parapsilosis showed the lowest growth, while R. mucilaginosa showed intermediate and C. glabrata the highest growth. In the plates incubated for seven days, the growth of C. parapsilosis and C. glabrata increased by 1 log over the third day. All isolates have the capacity to colonize and migrate through the matrix, increasing the potential risk to burn patients, who can develop severe and even fatal infections by invasive fungi.
Asunto(s)
Dermis Acelular/microbiología , Quemaduras/complicaciones , Quemaduras/microbiología , Levaduras/crecimiento & desarrollo , Quemaduras/patología , Candida glabrata/crecimiento & desarrollo , Candida glabrata/patogenicidad , Candida parapsilosis/crecimiento & desarrollo , Candida parapsilosis/patogenicidad , Interacciones Huésped-Patógeno , Humanos , Rhodotorula/crecimiento & desarrollo , Rhodotorula/patogenicidad , Factores de Riesgo , Piel/lesiones , Piel/microbiología , Piel/patología , Levaduras/aislamiento & purificación , Levaduras/patogenicidadRESUMEN
For a long-range transmission of motion between two movable parts apart from each other, transmitters that can precisely correlate these two motions should be properly incorporated into the system. However, such a motional relay is yet to be realized in artificial systems because of the lack of reliable methodologies for arranging a discrete number of motional parts. Herein, we report a correlated motion of two rotor molecules, which are coaxially arranged at a distance of 1.5 nm, through either Ag (+)- or Hg (2+)-assembled helical transmitters, leading to different frequencies of synchronized motion. A helix inversion in the transmitter was proven to strongly correlate the motions of both terminals. The X-ray analysis of the entity determined a quadruple-decker nonanuclear structure of the metal complex comprising two terminal rotor-like ligands closely attached to a central transmitter moiety. (1)H NMR analysis fully demonstrated the synchronized motion of the two rotors coaxially stacked and connected through the transmitter. Since the transmitter is composed of simple helical repeating units, the principle of helix inversion would be an efficient and widely applicable strategy for the long-range transmission of molecular motion.
RESUMEN
A molecular crank mechanism that enables transformation between rotational and translational motions was designed and synthesized. This molecule consists of a molecular ball bearing as the rotational part in which two disk-shaped rotors can rotate relative to each other through ligand exchange and flipping motion, and a [2]rotaxane as a translational part in which an axle molecule can move back-and-forth through the cavity of a crown ether-based macrocycle. (1)H NMR analysis revealed that these two motions influence each other.