Background:Staphylococcus aureus, an important human pathogen is one of the main causative agents of nosocomial infection. Virulence genes play a major role in the pathogenicity of this agent and its infections. Methicillin-Resistant Staphylococcus aureus (MRSA) isolates are major challenge among infectious agents that can cause severe infections and mortality. Methicillin-resistant S. aureus produces a unique type of Penicillin Binding Protein 2a (PBP2a) that has low affinity for β-lactam antibiotics. Most of the MRSA bacterial strains can also produce a leukotoxin as Panton-Valentine Leukocidin (PVL) that increases the virulence of MRSA strains and can cause severe necrotic pneumonia. The presence of pvl gene is a genetic marker for the MRSA populations.Objectives:The aim of this study was to explore the association of pvl and mecA genes in clinical isolates of MRSA.Materials and Methods:Fifty MRSA isolates were collected from 200 clinical samples from three different educational hospitals in Ahvaz, Iran, and identified by biochemical tests including catalase, oxidase, tube coagulase, mannitol fermentation, and sensitivity to furazolidone, resistance to bacitracin, PYR test and Voges-Proskauer test. Their resistance to methicillin was evaluated using the disc diffusion method. DNA was extracted by boiling and then the presence of pvl and mecA genes was investigated by the polymerase chain reaction method using specific primers.Results:The results revealed that mecA and pvl genes were positive for 15 (30%) and 3 (6%) of the isolates, respectively. None of mecA positive isolates was positive for pvl gene.Conclusions:It can be concluded from these results that fortunately the prevalence of pvl gene is low in MRSA isolates in this region and there is no association between the presence of pvl and mecA genes in these isolates.
Regeneration and restoring the function of the myocardial‐infracted hearts have been one of the constant challenges in medicine. Recently, tissue engineering, using biocompatible substrates and stem cells, holds a real promise to solve these problems. Herein, poly(lactic‐co‐glycolic acid) (PLGA) nanofibers and platelet‐rich plasma (PRP) enriched PLGA nanofibers (PLGA‐PRP) were fabricated by electrospinning. Scanning electron microscopy (SEM) demonstrated that fiber diameters in PLGA scaffolds with and without PRP were in the range of 500 ± 280 nm and fibers were also bead free, smooth, in random orientation, and with interconnected pores. During culture of the human‐induced pluripotent stem cells (iPSCs) on the nanofibrous scaffold, further differentiation of the iPSCs to cardiomyocytes was detected in PLGA‐PRP nanofibers compared to the PLGA. This improvement in differentiation potential was evaluated at the morphological, molecular gene, and protein expression levels using SEM, real‐time reverse transcription‐polymerase chain reaction (RT‐PCR), and immunocytochemistry, respectively. The results obtained in this study highlighted the significance of natural growth factors present in the artificial scaffold applied in cardiac tissue engineering according to the improvements in cell‐biomaterial interactions. Taken together, our result indicated that PRP‐incorporated PLGA could be considered as a great potential candidate to use for engineering suitable myocardium replacement constructs.
Background: Cystic echinococcosis (CE) is a zoonotic disease caused by infection with Echinococcus granulosus. Toll-like receptors (TLRs) as the first line of defense against various parasites play a critical role in sensing and triggering anti-parasite responses.
Methods: The study was conducted at the Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Iran in 2019. Ovine peripheral blood mononuclear cells (PBMCs) were stimulated with hydatid cyst-derived antigens including hydatid cyst fluid (HCF), germinal layer antigens (GL), somatic and excretory/secretory (ES) products of protoscoleces (PSC). To investigate whether the expression of TLR2 and TLR4 was altered during exposure to these antigens, PBMCs were stimulated with two different concentrations at different time points.
Results: After exposure of PBMCs to ES and somatic antigens of protoscoleces (PSC) the expression of TLR2 and TLR4 was down-regulated in comparison with control group. Similarly, HCF markedly down-regulated TLR2 and TLR4 transcripts independent of dose and time. GL antigens significantly down-regulated TLR2, while TLR4 expression was up-regulated as compared with control group.
Conclusion: Hydatid cyst-derived antigens could dysregulate the expression of TLR2 and TLR4 in ovine PBMCs, suggesting a possible mechanism to suppress host immunity to establish chronic infection.
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