Objective To evaluate the feasibility of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for identification and cluster analysis of Streptococcus suis. Methods Eighteen clinical isolates biochemically identified as Streptococcus suis were pre-treated by smearing formic acid method and formic acid-acetonitrile extraction method. The identification results and protein profiles of MALDI-TOF-MS method were analyzed and compared. A self-constructed database of profiling with better pretreatment method was established, and cluster analysis was performed on the 18 strains of Streptococcus suis. At the same time, PFGE homology analysis was performed to compare the results of the two genotyping. Results Both pretreatment methods could accurately identify Streptococcus suis with scores above 2.1. The protein fingerprint of formic acid and acetonitrile extraction method had a smoother baseline, fewer miscellaneous peaks and more identifiable ion peaks. Comparison of the results of homology typing showed that the homology results of MALDI-TOF-MS were significantly different from those of PFGE. Conclusion MALDI-TOF-MS can accurately identify Streptococcus suis for the strains pre-treated with formic acid method or formic acid-acetonitrile extraction method, and the formic acid-acetonitrile extraction method can obtain a better protein mapping. MALDI-TOF-MS can play a certain role in typing, but it still has some limitations and cannot completely replace the PFGE.

Objective To study the biological characteristics of clinical isolates of human infected Streptococcus suis type 2 in Zhongshan City from 2016 to 2019 and classify the strains using pulse-field gel electrophoresis (PFGE), and to provide a scientific basis for clinical prevention and treatment of porcine streptococcus suis disease. Methods Twelve strains of Streptococcus suis type 2 were collected from 2016 to 2019 and identified by automatic bacterial identification instrument. The carrying status of five major virulence genes of Streptococcus suis was detected by nucleic acid and protein analyzer, including capsular polysaccharide (cps2J), lysozyme-releasing protein (mrp), hemolysin (sly), glutamate dehydrogenase (gdh), and extracellular factor (ef). The susceptibility of Streptococcus suis to 12 kinds of commonly used antibiotics was determined by the broth microdilution method, and the homology analysis was carried out by PFGE method. Results Twelve strains of Streptococcus suis type 2 were divided into four virulence genotypes, mainly mrp-/sly+/ef+/cps2J+/gdh+ (6strains) and mrp-/sly-/ef+/cps2J+/gdh+(4strains). Drug susceptibility test results showed that 12 strains of Streptococcus suis type 2 were resistant to erythromycin, tetracycline and clindamycin, and they all were multi-resistant strains. According to the classification results of PFGE, the 12 strains were classified into 7 PFGE types based on 100% similarity coefficient. The PFGE band types of Streptococcus suis in the same year had high homology. Conclusion The virulence genotypes of 12 clinical isolates of human infected type 2 Streptococcus suis in Zhongshan from 2016 to 2019 are diverse, and the strains are resistant to multiple antibiotics. Most strains in the same year are the same clone strains. PFGE genotypes are not correlated with virulence genotypes and drug resistance spectrum.

Objective: To summarize the characteristics of cuffed-tunneled catheters insertion and investigate the values of cuffed-tunneled catheters in pediatric patients. Methods: Between March 2015 and July 2017, all the pediatric patients who received maintenance hemodialysis at least 3 consecutive months in our center were included. Sixteen cuffed-tunneled hemodialysis catheters were inserted in patients for long-term hemodialysis access. The clinical manifestations and complications were retrospectively reviewed. Results: Fifteen pediatric patients with end stage ranal disease (ESRD) were included in this study and they received 16 cuffed-tunneled catheters for long-term vascular access, including 10 males and 5 females; median age at start of catheter insertion was 11.5 (4.2-14.5) years. Body weight was (27.8±8.0)kg (16.0-39.4 kg) . The size and the length of the catheters were based on the height of patients as follows: 28 cm for (115.6±10.6) cm (102.0-130.0 cm) ,36 cm for (148.6±9.9)cm (140.0-167.0 cm) . Cuffed-tunneled catheters outcome: 10 cuffed-tunneled catheters were still functional at the end of the study; 5 catheters were removed after successful kidney transplantation. Catheter failure occurred in 1 out of 16 cuffed-tunneled catheters due to catheter-related infections. The median catheter survival time was 11.9 months (range 3.5-21.3 months). Complications of cuffed-tunneled catheters: Catheter placements operation was successful in 15 cases using ultrasound guidance. No serious complications were observed in any patients receiving catheter inserting operation. The overall rate of catheter-related infections and thrombosis/malposition was 6.3% and 18.7%, respectively. Conclusions Ultrasound guidance is suggested in pediatric patients during the catheters insertion. The size and the length of the catheters should be based on the height of patients. Cuffed-tunneled hemodialysis catheters could be effectively used for maintenance of hemodialysis vascular access for pediatric patients with ESRD.

Objective To assess the prognosis and effect on renal function of pediatric urolithiasis caused by melamine-contaminated milk powder (PUMMP) in a long-term follow-up.Methods One hundred and two of 8335 children (≤ 6-year-old) with history of consuming melamine-contaminated milk powder screened in our hospital were followed up for eighteen months after diagnosis. Urinary system ultrasonography, urinalysis, urinary microprotein profiles [microalbumin (ALBU), immunoglobulin G (IgG), and N-acetyl-β-D-glucosidase (NAG)], urinary melamine and cyanuric acid were examined in the first visit and at the end of follow-up. Results Follow-up was completed in 91 children and the stone was excreted in 82 children (90.1%).Stones less than 5 mm in diameter were most vulnerable to discharge, and stones larger than 10 mm could not be expelled without interventions. At the end of follow-up, no melamine or cyanuric acid was found in the urine samples of 74 patients. Urinalysis showed that incidences of proteinuria, microscopic hematuria and leukocyturia were 0%, 5.1% and 2.0%, which were significant different from those in the first visit (Pproteinutria=0.123, Phemnatuna=0.038 and Pleukocyhuris=0.005).Urinary microprotein profiles revealed that some children whose urinalysis was normal still presented glomerular and renal tubular injury and the abnormal rates were 8.8% and 12.1%respectively. The glomerular injury was mainly related to persistent stone, male and younger.Conclusions 90.1% of children with PUMMP passes urinary stones at the end of follow-up.Stone size is the major risk factor of discharge. No melamine or cyanuric acid is found in the urine of children. After eighteen months, glomerular and renal tubular injury is still found in some patients. Further follow-up is necessary.

Inflammation caused by chronic liver is primarily responsible for the occurrence and pathological progression of liver fibrosis. In the process of liver fibrosis, a large number of activated inflammatory signals promote the transformation of hepatic stellate cells (HSC) into myofibroblasts (MF), which eventually leads to the massive secretion and deposition of extracellular matrix (ECM) and the formation of scar tissue in the liver. To provide literature references for clinical diagnosis and treatment, this paper reviews the roles of HSC, Kupffer cells (KC), inflammasomes and inflammatory signaling in liver fibrosis.