Microbial Warfare on Three Fronts: Mixed Biofilm of Aspergillus fumigatus and Staphylococcus aureus on Primary Cultures of Human Limbo-Corneal Fibroblasts

BackgroundCoinfections with fungi and bacteria in ocular pathologies are increasing at an alarming rate. Two of the main etiologic agents of infections on the corneal surface, such as Aspergillus fumigatus and Staphylococcus aureus, can form a biofilm. However, mixed fungal–bacterial biofilms are rarely reported in ocular infections. The implementation of cell cultures as a study model related to biofilm microbial keratitis will allow understanding the pathogenesis in the cornea. The cornea maintains a pathogen-free ocular surface in which human limbo-corneal fibroblast cells are part of its cell regeneration process. There are no reports of biofilm formation assays on limbo-corneal fibroblasts, as well as their behavior with a polymicrobial infection.ObjectiveTo determine the capacity of biofilm formation during this fungal–bacterial interaction on primary limbo-corneal fibroblast monolayers.ResultsThe biofilm on the limbo-corneal fibroblast culture was analyzed by assessing biomass production and determining metabolic activity. Furthermore, the mixed biofilm effect on this cell culture was observed with several microscopy techniques. The single and mixed biofilm was higher on the limbo-corneal fibroblast monolayer than on abiotic surfaces. The A. fumigatus biofilm on the human limbo-corneal fibroblast culture showed a considerable decrease compared to the S. aureus biofilm on the limbo-corneal fibroblast monolayer. Moreover, the mixed biofilm had a lower density than that of the single biofilm. Antibiosis between A. fumigatus and S. aureus persisted during the challenge to limbo-corneal fibroblasts, but it seems that the fungus was more effectively inhibited.ConclusionThis is the first report of mixed fungal–bacterial biofilm production and morphological characterization on the limbo-corneal fibroblast monolayer. Three antibiosis behaviors were observed between fungi, bacteria, and limbo-corneal fibroblasts. The mycophagy effect over A. fumigatus by S. aureus was exacerbated on the limbo-corneal fibroblast monolayer. During fungal–bacterial interactions, it appears that limbo-corneal fibroblasts showed some phagocytic activity, demonstrating tripartite relationships during coinfection.

Protocol optimization for obtaining the culture of rat dermal fibroblasts

Introduction. Obtaining primary cultures of fibroblasts is necessary for conducting experimental studies to investigate the basic cell response mechanisms to various stimuli. Despite the widespread use of fibroblast cultures, methods for obtaining them from the skin are not standardized. The aim of the studywas to find the optimal conditions to obtain a fibroblast culture from rat skin using enzymatic tissue disaggregation. Materials and methods. The fibroblast culture was obtained from the dermis of 18 male Wistar rats (N=12, 5–6-week-old, and 60–65 g body weight; N=6, 8–10-week-old rats, and 160–180 g body weight). A series of experiments was carried out to obtain a fibroblast culture with selecting the collagenase type and defining its concentration and exposure time. Results.An optimized protocol to obtain rat dermis fibroblasts is presented. Moreover, the problems of obtaining a culture and practical aspects of its use are discussed. Conclusion. When obtaining a primary culture of rat skin fibroblasts we should consider the following fac-tors: the type of the enzyme, its concentration, and exposure time; the age of the animals; the area of skin graft collection. In young rats, the optimal result was achieved when the cells were isolated from the axillary zone using collagenase type II at a 1 mg/ml concentration during a 90-minute exposure. In adult animals, the enzymatic effect of collagenase type II on the skin graft obtained from the back was optimal at a 5 mg/ml concentration during a 120-minute exposure. Keywords: fibroblast culture, dermis, preparation protocols, rats

About the effectiveness of cell technologies in extensive soft tissue defects plasty

Fetal fibroblast culture transplantation results were evaluated in the treatment of 18 burn victims. Comparison group consisted of 18 burn patients received medical care without cellular technologies utilization. The main comparison parameters in the study groups: the timing of the first stage of autodermoplasty; the number of autodermoplasties during the treatment; hospitalization duration; the newly formed epidermis area estimation. Fetal fibroblast culture transplantation in burn patients with extensive skin defects was performed on average 14,883,56 days after the injury. The timing of the first stage of autodermoplasty did not differ in the main and control groups, not exceeding an average of 19,122,01 days (p=0,48). An average of 2,710,67 surgeries using cell technologies performed in patients of the study group. The use of fetal fibroblasts culture in patients with extensive skin defects reduces the need for autodermoplasty by 1,6 times due to the granulation tissue formation and the epidermal growth beginning 7 days after and complete epidermal formation 14 days after transplantation. Regenerative medicine technologies utilization in patients with extensive skin lesions is possible and appropriate. Due to the fetal fibroblasts culture transplantation a kind of temporary biological coating is formed in the wound. It accelerates the wound healing process phase change from exudation to proliferation and the preparation of skin defects for autodermoplasty, expanding the possibilities of effective patients treatment.

Changes in expressions of genes involved in the regulation of cellular processes in mucopolysaccharidoses as assessed by fibroblast culture-based transcriptomic analyses

Recent studies indicated that apart from lysosomal storage of glycosaminoglycans (GAGs), secondary and tertiary changes in cellular processes may significantly contribute to development of disorders and symptoms occurring in mucopolysaccharidoses (MPS), a group of lysosomal storage diseases in which neurodegeneration is specific for most types and subtypes. In this report, using transcriptomic data, we demonstrate that regulation of hundreds of genes coding for proteins involved in regulations of various cellular processes is changed in cells derived from patients suffering from all types and subtypes of MPS. Among such genes there are 10 which expression is significantly changed in 9 or more (out of 11) MPS types/subtypes; they include IER3IP1, SAR1A, TMEM38B, PLCB4, SIN3B, ABHD5, SH3BP5, CAPG, PCOLCE2, and MN1. Moreover, there are several genes whose expression is changed over log2 > 4 times in some MPS types relative to control cells. The above analysis indicates that significant changes in expression of genes coding for various regulators of cellular processes may considerably contribute to development of cellular dysfunctions, and further appearance of specific symptoms of MPS, including neurodegeneration.