Objective:To analyze molecular epidemiological characteristics of drug resistance genes and carbapenem resistance of Pseudomonas aeruginosa (PA) in rural well water. Methods:According to Citation of Natural Mineral Water Inspection (GB 8538-2016), a total of 112 well water samples were tested in Juye county of Shandong province, and PFGE and drug susceptibility test were conducted for the identified PA strains. After PCR identification of carbapenem resistance genes, S1-PFGE and Southern blotting were used to determine the location of drug resistance genes, and combined experiments were used to determine gene transferability. Results:The detection rate of PA in rural well water samples in Juye county of Shandong province was 54.46% (61/112). The 61 strains could be divided into 56 PFGE types. There were 2 strains with 100.00% consistent band types, and there was no obvious predominant band type. The results of drug susceptibility experiments showed that 93.44% (57/61) were multi-drug resistant strains, and there were 2 strains carrying blaVIM-2, both of which were located on the plasmid, and both of them were transferred horizontally with the plasmid. Conclusion:PA carrying carbapenem resistance genes was detected in well water of rural communities in Juye country, and there is the possibility of horizontal transmission of such resistance genes.

Objective: To analyze the antimicrobial resistance and multilocus sequence typing (MLST) results of extended-spectrum β-lactamase (ESBLs)-producing Escherichia coli in rural residents in villages with pig breeding farms in a county of Shandong province. Methods: Antimicrobial susceptibility testing was performed with agar dilution method by using 360 ESBLs-producing E. coli strains from fresh stool samples of rural residents in villages with pig breeding farms in a county of Shandong. PCR was conducted to amplify the CTX-M, TEM, SHV genes and capillary electrophoresis was used to screen positive strains in July, 2016. MLST was performed for molecular typing analysis, and eBURST v3.0 software was used for cluster analysis. Results: Among 360 strains of ESBLs-producing E. coli, the resistance rates to cefotaxime, tetracycline, trimethoprim-sulfamethoxazole and florfenicol were 100.0% (360/360), 82.2% (296/360), 81.1% (292/360) and 80.3% (289/360), respectively. The positive rate of CTX-M gene was 99.2% (357/360), in which the positive rate of CTX-M-9 was 35.6% (128/360) and the positive rate of CTX-M-1 was 24.4% (88/360). The positive rate of TEM gene was 26.9% (97/360). A total of 132 STs were identified through MLST. The predominant ST was ST10, accounting for 12.5% (45/360). Cluster analysis showed that CC10 was the most important clone group, including 39 ST clones, involving 148 strains (41.1%). Conclusions The drug resistances of ESBLs-producing E. coli to cefotaxime, tetracycline, trimethoprim-sulfamethoxazole and flurfenicol are serious in this rural area. There is a small-scale clustering of CC10 and transmission mode from animals to humans might exist.