Etiological characteristics of a foodborne diseases outbreak of Salmonella enteritidis in Suzhou / 上海预防医学

ObjectiveTo determine the pathogenic cause in a foodborne diseases outbreak of Salmonella enteritidis in a company in Suzhou City， and provide evidence for epidemiological investigation and guidance for clinical treatment. MethodsRelevant specimens were examined for Salmonella， Shigella， Staphylococcus aureus and Vibrio parahaemolyticus. Furthermore， for the isolated Salmonella enteritidis， a micro broth dilution method was used for antimicrobial susceptibility testing， and pulsed field gel electrophoresis （PFGE） was used for molecular typing. ResultsA total of 44 strains of Salmonella enteritidis were detected from 43 anal swabs of the patients in the outbreak， 7 anal swabs of canteen employees， 31 retained food specimens and 6 environmental specimens. A total of 15 antimicrobial susceptibility testings showed that the 44 strains had the same antimicrobial resistance spectrum， which was 100% resistant to cefazolin， ampicillin， ampicillin/sulbactam， polymyxin E and nalidixic acid， suggesting a multi-drug resistance to more than three antibiotics. PFGE cluster analysis showed that the 44 strains had a 100% of genetic similarity. ConclusionThe outbreak is caused by the consumption of food contaminated with Salmonella enteritidis. The isolated strains have multi-drug resistance， which could guide appropriate antimicrobial treatment based on the antimicrobial susceptibility testing.

Persistent Malfunction of Glymphatic and Meningeal Lymphatic Drainage in a Mouse Model of Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a devastating cerebrovascular event that often is followed by permanent brain impairments. It is necessary to explore the pathogenesis of secondary pathological damages in order to find effective interventions for improving the prognosis of SAH. Blockage of brain lymphatic drainage has been shown to worsen cerebral ischemia and edema after acute SAH. However, whether or not there is persistent dysfunction of cerebral lymphatic drainage following SAH remains unclear. In this study, autologous blood was injected into the cisterna magna of mice to establish SAH model. One week after surgery, SAH mice showed decreases in fluorescent tracer drainage to the deep cervical lymph nodes (dcLNs) and influx into the brain parenchyma after injection into the cisterna magna. Moreover, SAH impaired polarization of astrocyte aquaporin-4 (AQP4) that is a functional marker of glymphatic clearance and resulted in accumulations of Tau proteins as well as CD3⁺, CD4⁺, and CD8⁺ cells in the brain. In addition, pathological changes, including microvascular spasm, activation of glial cells, neuroinflammation, and neuronal apoptosis were observed in the hippocampus of SAH mice. Present results demonstrate persistent malfunction of glymphatic and meningeal lymphatic drainage and related neuropathological damages after SAH. Targeting improvement of brain lymphatic clearance potentially serves as a new strategy for the treatment of SAH.

Research on the feasibility of a magnetic-coupling-driven axial flow blood pump / 生物医学工程学杂志

A new-designed axial flow blood pump, dived by magnetic coupling and using internal hollow brushless DC motor and inlet and outlet in line with impeller, was tested in mimic circuit. The results showed good performance of the new pump and indicated that its hydrodynamic characteristic can meet the demands of clinical extracorporeal circulation and auxiliary circulation.