ABSTRACT
Objective:To investigate the concentration level of chloroform in the water of swimming pool in Baoan District of Shenzhen City，and determine the risk factors. Methods:During May and July，2019，a total of 110 water samples from 40 swimming pools were collected in Xin’an subdistrict of Bao’an District for the examination of chloroform routine indicators. In addition， 38 pipe water samples were collected for the examination of chloroform and free residual chlorine． Results:The concentration of chloroform in the swimming pools was determined to be （43.400±27.802） μg/L with the median of 37.343 μg/L. Chloroform was correlated positively with total bacterial count（P<0.05），turbidity， free chlorine residual， and PH value（P<0.01）. Conclusion:The disinfection quality of swimming pool water in Bao’an District remains low. It is necessary to determine the risk factors associated with chloroform in the swimming pool and further reduce the concentration level of disinfection by-products.
ABSTRACT
OBJECTIVE@#To study the distribution and drug resistance of pathogens causing periprosthetic infections after hip and knee arthroplasty, and to formulate prevention and treatment strategies for drug-resistant bacteria.@*METHODS@#The data of 146 cases of periprosthetic infection after primary hip and knee arthroplasty from 2010 to 2015 were collected, including 111 cases of periprosthetic infection after hip arthroplasty and 35 cases of periprosthetic infection after knee arthroplasty. The culture positive rate, pathogenic bacteria composition and drug resistance rate were counted over the years, and the change trend of pathogen distribution and drug resistance was analyzed.@*RESULTS@#One hundredand eight strains of pathogenic bacteria were detected in 146 cases, and the positive rate of culture was 73.97%. Gram positive bacteria accounted for 55.48%, Staphylococcus epidermidis and Staphylococcus aureus accounted for 25.34% and 15.07% respectively. Gram negative bacteria accounted for 13.01%, including Enterobacter cloacae, Pseudomonas aeruginosa and Escherichia coli. There were 4 cases of Mycobacterium tuberculosis infection and mixed infection. The results of culture over the years showed that the constituent ratio of Gram positive bacteria had an increasing trend, fluctuating from 39.13% to 76.47%. The results of drug sensitivity showed that the pathogens were highly resistant to β-lactams, quinolones, clindamycin and gentamicin, and the drug resistance rate was increasing, but it was still sensitive to rifampicin, nitrofurantoin, tigecycline, linezolid and vancomycin.@*CONCLUSION@#Gram positive bacteria are the main pathogens of periprosthetic infection, and the proportion is increasing gradually.The pathogens have high resistance to many kinds of antibiotics, and the resistance rate is still increasing. To strengthen the monitoring of the distribution and drug resistance of pathogenic bacteria is helpful to grasp its change trend and formulate targeted prevention and control strategies.