ABSTRACT
Objective:To evaluate the relationship between the Panton-Valentine leukocidin (pvl) strain and clinical characteristics, and to describe the molecular biological characteristics of invasive Staphylococcus aureus ( S. aureus) infected clinical isolates. Methods:The isolates of S. aureus caused by invasive infection were collected in Beijing Children's Hospital Affiliated to Capital Medical University from January 2016 to December 2019, and the clinical data of the corresponding children were collected retrospectively using electronic medical records. Multilocus sequence typing, spa typing and pvl gene were analyzed using the PCR. In addition, the minimum inhibitory concentrations (MIC) of antibiotics of all isolates were detected by the micro-broth dilution method, and the isolates were divided into the pvl+ and pvl- groups according to whether or not the S. aureus isolates carried pvl. The t test and the Mann-Whitney U test were used to compare the clinical symptoms between the pvl+ and pvl- groups. Chi-square test was used to compare the drug susceptibility between the two isolates. Results:A total of 127 cases of invasive S. aureus infection were collected during the study period. The white blood cell count, neutrophil count, and C-reaction protein level in the pvl+ group were significantly higher than those in the pvl- group ( P=0.001, P=0.001, P=0.005). The rate of pvl carrier was 44.9%. Among 57 pvl+ pathogenic strains, 64.9% (37/57) were MRSA. The multidrug resistance rate of pvl- isolates was higher than that of pvl+ isolates (70% vs. 49.12%, P=0.02). Conclusions:In invasive S. aureus infection, pvl+ strain is associated with elevated inflammatory markers in children. the positive rate of pvl is higher in clinical isolates, and the multidrug resistance rate of pvl- S. aureus is higher.
ABSTRACT
10.3969/j.issn.2095-4344.2013.24.016
ABSTRACT
Osteoarthritis is one of the most common diseases seen in clinical practice. Cartilage survives in the hypoxic microenvironment. Hypoxia-inducible factor-1α (HIF-1α) is a key nuclear transcription factor which mediates the hypoxic response of cells. HIF-1α gene is an important regulator for the adaptation of articular cartilage to the hypoxic environment. It is important for formation of articular cartilage, energy metabolism and matrix synthesis. If the HIF-1α gene is knocked out, the cartilage can not maintain their normal morphology and function, which may lead to cartilage degeneration, and result in diseases such as osteoarthritis. Chinese herbal medicines can regulate the expression of HIF-1α gene and supply a therapy method for osteoarthritis. In this paper, the authors review the situation of the correlation between HIF-1α and osteoarthritis cartilage degeneration examined in recent years.