Objective:To investigate the clinical characteristics of pediatric methicillin-resistant Staphylococcus aureus (MRSA) infection and the antibiotic sensitivity of the isolates. Methods:The clinical data of children with MRSA infection and antibiotic sensitivity of the isolates from 11 children′s hospitals in Infectious Diseases Surveillance of Paediatrics (ISPED) group of China between January 1, 2018 and December 31, 2018 were collected retrospectively. The children′s general condition, high-risk factors, antimicrobial therapy and prognosis, differences in clinical disease and laboratory test results between different age groups, and differences of antibiotic sensitivity between community-acquired (CA)-MRSA and hospital-acquired (HA)-MRSA were analyzed. The t test and Wilcoxon rank sum test were used for statistical analysis of the quantitative data and Chi-square test were used for comparison of rates. Results:Among the 452 patients, 264 were males and 188 were females, aged from 2 days to 17 years. There were 233 cases (51.5%) in the ≤1 year old group, 79 cases (17.5%) in the>1-3 years old group, 29 cases (6.4%) in the >3-5 years old group, 65 cases (14.4%) in the >5-10 years old group, and 46 cases (10.2%) in the>10 years old group. The main distributions of onset seasons were 55 cases (12.2%) in December, 47 cases (10.4%) in February, 46 cases (10.2%) in November, 45 cases (10.0%) in January, 40 cases (8.8%) in March. There were 335 cases (74.1%) CA-MRSA and 117 (25.9%) cases HA-MRSA. Among all cases, 174 cases (38.5%) had basic diseases or long-term use of hormone and immunosuppressive drugs. During the period of hospitalization, 209 cases (46.2%) received medical interventions. There were 182 patients (40.3%) had used antibiotics (β-lactams, glycopeptides, macrolides, carbapenems, oxazolones, sulfonamides etc) 3 months before admission. The most common clinical disease was pneumonia (203 cases), followed by skin soft-tissue infection (133 cases), sepsis (92 cases), deep tissue abscess (42 cases), osteomyelitis (40 cases), and septic arthritis (26 cases), suppurative meningitis (10 cases). The proportion of pneumonia in the ≤1 year old group was higher than the >1-3 years old group,>3-5 years old group,>5-10 years old group,>10 years old group (57.5% (134/233) vs. 30.4% (24/79), 31.0% (9/29), 38.5% (25/65), 23.9% (11/46), χ 2=17.374, 7.293, 7.410, 17.373, all P<0.01) The proportion of skin and soft tissue infections caused by CA-MRSA infection was higher than HA-MRSA (33.4% (112/335) vs. 17.9% (21/117), χ 2=10.010, P=0.002), and the proportion of pneumonia caused by HA-MRSA infection was higher than CA-MRSA (53.0% (62/117) vs. 42.1% (141/335), χ 2=4.166, P=0.041). The first white blood cell count of the ≤1 year old group was higher than that children > 1 year old ((15±8)×10 9/L vs. (13±7)×10 9/L, t=2.697, P=0.007), while the C-reactive protein of the ≤1 year old group was lower than the 1-3 years old group,>5-10 years old group,>10 years old group (8.00 (0.04-194.00) vs.17.00 (0.50-316.00), 15.20 (0.23-312.00), 21.79(0.13-219.00) mg/L, Z=3.207, 2.044, 2.513, all P<0.05), there were no significant differences in procalcitonin (PCT) between different age groups (all P>0.05). After the treatment, 131 cases were cured, 278 cases were improved, 21 cases were not cured, 12 cases died, and 10 cases were abandoned. The 452 MRSA isolates were all sensitive to vancomycin (100.0%), linezolid (100.0%), 100.0% resistant to penicillin, highly resistant to erythromycin (85.0%, 375/441), clindamycin (67.7%, 294/434), less resistant to sulfonamides (5.9%, 23/391), levofloxacin (4.5%, 19/423), gentamicin (3.2%, 14/438), rifampicin (1.8%, 8/440), minocycline (1.1%, 1/91). The antimicrobial resistance rates were not significantly different between the CA-MRSA and HA-MRSA groups (all P>0.05). Conclusions:The infection of MRSA is mainly found in infants under 3 years old. The prevalent seasons are winter and spring, and MRSA is mainly acquired in the community. The main clinical diseases are pneumonia, skin soft-tissue infection and sepsis. No MRSA isolate is resistant to vancomycin, linezolid. MRSA isolates are generally sensitive to sulfonamides, levofloxacin, gentamicin, rifampicin, minocycline, and were highly resistant to erythromycin and clindamycin. To achieve better prognosis. clinicians should initiate anti-infective treatment for children with MRSA infection according to the clinical characteristics of patients and drug sensitivity of the isolates timely and effectively.

Objective: To investigate the relationship between the EBV-induced liver injury and caspase-3/6 in children. Methods: Data of 249 patients seen from July 2016 to June 2017 who got infection with EBV were collected in second affiliated hospital of Wenzhou Medical University and the patients were divided into two groups; 168 patients who were diagnosed with hepatitis were selected for abnormal liver function group, laboratory tests were performed in acute phase and convalescent phase. Meanwhile the 81 patients, whose liver function were normal were selected for normal liver function group. Two ml of blood plasma was collected from each patient from both groups at the beginning and after a week’s treatment of the abnormal liver function group. The patients were aged from 1 to 14 years. The abnormal liver function group was further divided into four groups: young children (1-3 years old), preschool children (4-6 years old), school children (7-10 years old), teenagers (10-14 years old). Firstly, we recorded their alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), gamma glutamyl transpeptidase (GGT) and direct bilirubin (DBIL), then by the use of enzyme linked immunosorbent assay (ELISA) we measured the protein level of caspase-3 and caspase-6. Results: In the group of abnormal liver function group, in the acute phase of the teenagers the level of ALT, caspase-3 and caspase-6 are improved significantly(927.2±82.5 vs. 158.5±41.4, P<0.001, 169.8±52.8 vs. 91.5±10.1, P<0.001, P<0.05, 82.2± 2.6, P<0.001, 965.8±31.5, P<0.001, 184.8±14.3, P<0.001), while the AST, TBLL, GGT and DBLL had no significant difference. Conclusions In the process of EBV-induced liver injury, there was a linear correlation between the increase of caspase-3/6 and ALT in the acute stage, suggesting that EBV-induced liver injury is closely related to caspase-3/6.

To develop Senecavirus A (SVA) virus-like particles (VLPs), a recombinant prokaryotic expression plasmid pET28a-SVA-VP031 was constructed to co-express SVA structural proteins VP0, VP3 and VP1, according to the genomic sequence of the field isolate CH-FJ-2017 after the recombinant proteins were expressed in E .coli system, and purified by Ni+ ion chromatographic method. The SVA VLPs self-assemble with a high yield in vitro buffer. A typical VLPs with an average diameter of 25-30 nm which is similar to native virions by using TEM detection. Animals immunized by SVA VLPs shown that the VLPs induced high titers neutralizing antibodies in Guinea pigs. This study indicated that the VLPs produced with co-expressing SVA structural proteins VP0, VP3 and VP1 in prokaryotic system is a promising candidate and laid an important foundation for the development of a novel SVA VLPs vaccine.
Animals ; Antibodies, Neutralizing ; Escherichia coli/genetics* ; Genomics ; Guinea Pigs ; Picornaviridae/genetics*