Objective: To design the proficiency testing (PT) project (No. NIFDC-PT-183) for assays of bismuth potassium citrate capsules and organize to assess the proficiency of complexometric titration in laboratories, and provide some technical analyses and advices.
Methods: Two groups of samples with different concentration were prepared. The uniformity was evaluated with one-way analysis of variance and the stability was confirmed with t-test, whose results all conformed the requirements. The samples with three combinations were randomly distributed to 279 laboratories. The determination was performed according to the assays of bismuth potassium citrate capsules in Volume Ⅱ of the Chinese Pharmacopoeia 2015. The median value and normalized interquartile range (NIQR) of robust statistical analysis was adopted and Z-scores were used to evaluate the results from each of laboratories.
Results: Among 279 laboratories, 240 laboratories results were satisfactory, 23 were questionable, and the other 16 were unsatisfied. The satisfaction rate was 86.0%.
Conclusion: The overall capacity of national laboratories for assays of bismuth potassium citrate capsules is good while a portion of participants require further improvement.

A high performance liquid chromatography tandem mass spectrometric ( HPLC-MS/MS ) method was developed for the determination of seven perfluorinated alkyl acidin ( C4-C10 ) and perfluorooctane sulfonate in water. After the particulate was removed by leaching, surrogate standard was added, then the sample was loading to a pre-conditioned WAX cartridge for purification, and then the eluent was concentrated and analyzed by HPLC-MS/MS. Due to the situation that the fluoride polymer was unavoidable to be used in the LC system, a delay column was employed and the perfluorooctanoic acid ( PFOA ) of interference was departed from the PFOA in sample. The method detection limit ( MDL) of PFOA was 0. 8 ng/L, and the lowest quantitative concentration (LQC) was 3. 2 ng/L. For other compounds, the MDL was ranged from 0. 2 to 1. 2 ng/L, and the LQC was 0. 8-4. 8 ng/L. This method also had good reproducibility, for six duplicated samples, the relative standard deviations ( RSD ) of all target compounds were less than 16%. And the recoveries of target compounds at six spiked matrix samples ranged from 87% to 129%, and the RSD were less than 15%. Because of the connection of delay column, the background was well controlled, and a relatively lower MDL were obtained.

OBJECTIVETo elucidate the epidemic condition and molecular subtyping of ciprofloxacin and cefotaxime co-resistant Salmonella Indiana (S. Indiana) isolated from retail chicken carcasses in six provinces of China.

METHODSA total of 2 647 Salmonella strains isolated from retail chicken carcasses collected from six provinces of China were subjected to antimicrobial susceptibility testing. All Salmonella isolates co-resistant to ciprofloxacin and cefotaxime were further characterized by serotyping, extended-spectrum beta-lactamases (ESBLs) producing strains screening and pulsed field gel electrophoresis (PFGE) typing.

RESULTSAmong 2 629 Salmonella isolates tested, 227 (8.52%) isolates were co-resistant to ciprofloxacin and ceftazidime/cefotaxime (Beijing: 11.67% (99/874), Jilin: 8.20% (60/726), Guangdong: 1.39% (7/502), Jiangsu: 15.61% (42/260), Shaanxi: 8.56% (16/186), Inner Mongolia: 0 (0/81)), and 224 of them were identified as S. Indiana. 213 (95.10%) isolates of S. Indiana were ESBLs producing strains. All ciprofloxacin and cefotaxime co-resistant S. Indiana isolates developed a multi-drug resistant profile and 17.86% (40/224) of them were resistant to all antibiotics tested except carbapenems, and 50.89% (114/224) of them resistant to 9 antibiotics, additionally, 25.45% (57/224) of them showed multi-drug resistance to 8 antibiotics. All ciprofloxacin and cefotaxime co-resistant S. Indiana isolates were divided into 32 PFGE clusters and 150 PFGE patterns. Strains of S. Indiana from same or different sampling site and time seemed to either share the same PFGE patterns or be differential to each other in different regions.

CONCLUSIONThe results indicated that chicken carcasses collected from parts of China were heavily contaminated by ciprofloxacin and cefotaxime co-resistant S. Indiana and could serve as an important reservoir of ciprofloxacin and cefotaxime co-resistant Salmonella. Molecular subtyping results indicated that cross contamination or common pollution source might be in these strains.

Animals ; Anti-Bacterial Agents ; pharmacology ; Cefotaxime ; pharmacology ; Chickens ; microbiology ; China ; Ciprofloxacin ; pharmacology ; Drug Resistance, Multiple, Bacterial ; Electrophoresis, Gel, Pulsed-Field ; Food Contamination ; Food Microbiology ; Meat ; microbiology ; Salmonella ; classification ; isolation & purification ; Serotyping ; beta-Lactamases