Prevalence and antimicrobial resistance of Salmonella in retail foods in northern China

A total of 387 retail meat, seafood and milk powder samples were collected from nine cities in northern China in 2005 and screened for the presence of Salmonella. Salmonella strains isolated were subjected to serotyping and antimicrobial susceptibility testing. Salmonella was isolated from 81 (20.9%, 81/387) samples and classified into 23 serotypes. The isolates were frequently resistant to sulfamethoxazole (86.4%), sulfamethoxazole/trimethoprim (48.1%), nalidixic acid (30.9%), tetracycline (19.8%), carboxybenzylpenicillin (17.3%), amoxicillin (17.3%) and ampicillin (16.0%). The multiple resistance (resistance to ≥ 3 antibiotics) was found in 29.6% (n = 24) isolates. Additionally, 4 isolates from chicken displayed the ACSSuTNx profile, resistant to ampicillin, chloramphenicol, streptomycin, sulfonamide, tetracycline and nalidixic acid, in particular, strain HBS084 showing the resistance to as many as 20 antibiotics. Salmonella from chicken showed the higher frequency of antimicrobial resistance. Our findings indicate that in northern China food products of animal origin can be a source of exposure for consumers to multiresistant Salmonella strain

Kinetics of Fluidized Bed Treatment to Adsorb Mercury

Fluidized bed treatment to adsorb mercury was discussed. The adsorption model to discuss kinetics was proposed. Over-all coefficient of mass tansfer was measured and its correlated equation was obtained. The simulation of concentration variation by the model was cbincident with experimental data. The multi-stage classification model was proposed to apply the adsorption model to particles with wide range of size. Fluidized bed treatment for actual wastewater was discussed. Concentration variation in the treatment was able to be simulated by the model that over-all coefficient of mass transfer obtained from experiments of actual wastewater was used