Objective: To investigate the content of ethylparaben in potassium chloride solution.Methods: According to the guidance for antibacterial effect test stated in Chinese Pharmacopoeia(the 4th volume of 2015 edition), 5 standard bacterial strains including Staphylococcus aureus,Escherichia coli,Pseudomonas aeruginosa,Candida albicans and Aspergillus niger were used as the challenging strains.Using the logarithm decrease of bacteria number as the index, the antimicrobial effectiveness of ethylparaben at different concentrations was studied to screen out the optimal concentration in the solution.Results: The growth of the 5 standard bacterial strains was inhibited effectively by potassium chloride solution containing 0.05% ethylparaben, which was also the minimum effective concentration.Conclusion: 0.05% Ethylparaben is suitable as the bacteriostatic agent for potassium chloride solution.

The elements of the teaching system driven by the "Internet +" era are undergoing fundamental changes . Intelligent teaching platform is gradually becoming an important guarantee of the reform of teaching system elements for educators while they are teaching. With the support of intelligent teaching platform, the elements of teaching system break through the limitation of classroom teaching, the traditional structure of teacher-centered is disintegrating, the individual roles of teachers and students are being reconstructed , the teaching content is greatly enriched , and the function of teaching media is becoming more and more intelligent. This thesis, which will take the learning support function of the WeChat Public Platform of "Medical History" as an example by drawing lessons from the reversed classroom teaching mode, carries out the mixed teaching model of Chinese Medical History course by three stages: pre-class autonomous learning, in-class knowledge perfection and after-class knowledge transfer. It will elaborate its overall influence on the elements of the teaching system of Chinese Medical History and its important technical support for the reform of classroom teaching structure.

OBJECTIVETo investigate the nasal carriage of antibiotic-resistant pneumococci in children of < 5 years old in the following four cities, Beijing, Shanghai, Guangzhou and Xi'an.

METHODSA total of 647 pneumococci strains were isolated and detected. Minimal inhibition concentrations (MICs) of antibiotics were determined by E-test. Disk diffusion test was used for the measurement of antimicrobial susceptibility.

RESULTSPrevalence of penicillin non-susceptible Streptococcus pneumoniae in the four cities was 41%, with Guangzhou (60.8%) ranking first, followed by Xi'an (45%), Shanghai (37%) and Beijing (25.9%). The majority of penicillin non-susceptibility isolates (23.9% - 53.8%) had a low level of resistance (MIC 0.64 - 1.5 microg/ml). The most sensitive antimicrobials in terms of percentage of susceptible organisms were amoxicillin-clavulanic acid (99.4%), followed by ceftriaxone (92.1%); cefurxime and cefaclor were slightly more sensitive than penicillin with susceptibility of 74.8% and 77.9%. Erythromycin, tetracycline and TMP-SMZ were highly resistant (83.6%, 82.1% and 76.2% respectively). Among erythromycin resistant isolates, 100% were resistant to azithromycin, 98.6% to clarithromycin, 97.2% to roxithromycin and spiramycin, and 96.6% to clindamycin. 97.2% (141/145) were typical of the macrolides-lincosamides-streptogramons B (MLSB) resistance phenotype, and 2.8% (4/145) were M phenotype. The group of PRSP was with significantly higher rates of non-susceptibility for ceftriaxone (18.4%), cefurxime (58.6%), cefaclor (53.4%), compared with the group of PEN-S (0.5%, 1.8% and 0.2%, respectively) and the rate of multi-drug resistance in the isolates of PRSP group (92.9%) was significantly higher than that of PEN-S group (59.2%).

CONCLUSIONThe rates of penicillin and multi-drug resistance among isolates of pneumococci carried nasally in are high children and the high prevalence of multi-drug resistance in the Chinese population may be becoming one of the most serious problems in this century.

Anti-Bacterial Agents ; pharmacology ; Child, Preschool ; China ; epidemiology ; Drug Resistance, Bacterial ; Drug Resistance, Multiple ; Humans ; Infant ; Infant, Newborn ; Prevalence ; Respiratory Tract Infections ; microbiology ; Streptococcus pneumoniae ; drug effects ; isolation & purification