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Staphylococcus aureus is an important pathogen of human infectious diseases, which can cause skin and soft tissue infections, endocarditis, necrotizing pneumonia, myelitis and other serious infectious diseases. With the use of antibiotics, Staphylococcus aureus is evolving to develop drug resistance; at the same time it produces a variety of virulence factors to attack the host. This article will review the recent advances of Staphylococcus aureus virulence factors associated with the three stages of infection and introduce the detection methods of virulence factors briefly.
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Tuberculosis is a kind of chronic infectious disease caused by Mycobacterium tuberculosis (MTB).Macrophages, as the main host cells against MTB ,play a crucial role in the natural and acquired immune response of the body.Under the stimulation of different inducing factors , macrophages can be polarized to M1-type macrophages and M2-type macrophages,which play different functions in the progression of tuberculosis.Further studies on the polarization signaling pathway of macrophages and dynamic balance between M1 and M2-type macrophages cells have provide a new way to explore the pathogenesis of tuberculosis.In addition, due to the importance of macrophage polarization in the development of MTB infection, the formation of tuberculous granuloma and prognosis of tuberculosis , the in-depth study on macrophages polarization will contribute to the development of new tuberculosis vaccines and immune agents , and lay an important theoretical foundation for the prevention and treatment of tuberculosis .
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Objective To analyze the changing antibiotic resistance profile of the Klebsiella pneumoniae strains isolated from blood cultures during the last 9 years in our hospital for rational use of antibiotics. Methods Antibiotic resistance of the K. pneumoniae strains isolated from blood cultures from 2009 to 2017 was retrospectively analyzed. Medical records of the corresponding inpatients were reviewed and analyzed. Results A total of 6 917 bacterial strains were isolated from blood cultures between 2009 and 2017, of which 311 strains (4.5％) were Klebsiella pneumoniae. Complete antimicrobial susceptibility data were available for 298 of the 311 strains. The K. pneumoniae strains isolated from blood cultures showed increasing resistance rate to the antimicrobial agents in the nine-year period. The resistance rates to piperacillin-tazobactam, cefotetan, amikacin, carbapenem antibiotics increased from 0 to 48.6％. The prevalence of CRKP increased from 0 in 2009 to 48.7％ in 2017. The inpatients with K. pneumoniae isolate from blood cultures were mainly found in general surgery, cardio-thoracic surgery department, emergency room, and pediatrics surgery department. Significant difference was found between CRKP-associated inpatients and non-CRKPassociated inpatients in the time to detection of K. pneumoniae, exposure to antimicrobial agents, invasive procedure, length of hospital stay, and prognosis (P＜0.001). Conclusions The antibiotic resistance profile of the K. pneumoniae strains isolated from blood cultures showed a rising tendency during the period from 2009 to 2017. Clinical microbiology laboratory should pay more attention to strengthening antibiotic resistance surveillance. Clinicians should reduce the use of invasive procedures and use appropriate antimicrobial agents to prevent the emergence of antibiotic-resistant strains.
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Matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) is an emerging tool for detecting microorganisms. It can be used not only for rapid identification of microorganisms, but also for the research of resistance mechanisms. Producing β-lactamase is the main mechanism for resistance of β-lactam antibiotics in Gram-negative bacilli. Currently using MALDI-TOF MS for rapid detection of bacterialβ-lactamase has been widely reported, including detection of β-lactam hydrolysis activity of β-lactamase, direct detection of β-lactamase molecule, peptide and relevant proteins, and detection of the single nucleotide polymorphisms (SNPs) of β-lactamase gene. This paper reviews current application of MALDI-TOF MS to the detection of β-lactamase based on the latest research findings.
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Illegal medical advertisement induces the patient's choice of seeking for medical care,A wrong chioce could cause that the patient loses the opportunity of obtaining the proper medical diagnosis and treatment in time.This is the root cause of regulation of medical advertisement in law.The law has strict rules on the release master and contents of legal medical advertisement.Violating this regulation can be the basis of administrative saction,civil liability for damages and even criminal punishment.
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BACKGROUND:The smal intestinal submucosa has good biocompatibility and biodegradability, and also contains a variety of growth factors that can significantly promote celladhesion, proliferation and differentiation. Currently, the smal intestinal submucosa has been widely used in bone and cartilage, blood vessels, skin, bladder, smooth muscle and pancreatic tissue repair, showing good performance as a tissue-engineered cellscaffold. OBJECTIVE:To investigate the in vitro feasibility of tissue engineered periosteum constructed by porcine smal intestinal submucosa and osteoblasts differentiated from bone marrow mesenchymal stem cells. METHODS:Bone marrow mesenchymal stem cells were harvested from 2-week-old healthy New Zealand rabbits by using adherent method, and then cells were cultured, induced, differentiated and identified in vitro. Fol owing induced differentiation and identification, the bone marrow mesenchymal stem cells were compounded with porcine smal intestinal submucosa to fabricate tissue engineered periosteum. The adhesion, growth, and proliferation of cells on the materials were observed. RESULTS AND CONCLUSION:At 5 days after inoculation, the cells receiving osteogenic induction could quickly adhere and proliferate on the surface of porcine smal intestinal submucosa and be interconnected;at 10 days, the desmosomes formed among the cells, cellprocesses from osteoblasts were visible and attached to the smal intestine submucosa;at 15 days, cellproliferation and secretion of matrix appeared, and multi-layer membrane-like structure formed on the surface of the smal intestine submucosa. These findings indicate that after osteogenic induction, the bone marrow mesenchymal stem cells can be combined with porcine smal intestinal submucosa to construct a tissue engineered periosteum, which is hoped to be an ideal scaffold for tissue engineering.
