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Infections due to aquatic products that are contaminated with Salmonella spp. are great risks to public health, however, epidemiological information and risk factors regarding these Salmonella contamianted food are limited in China. The study aimed to examine the incidence of Salmonella spp. in fresh aquatic products in China, and the MLST patterns and antimicrobial-resistance profiles of the Salmonella isolates identified. Out of the 300 aquatic food samples purchased from retail markets in 15 provincial Chinese capitals during 2015.6–2016.6, sixteen (5.3%) were found to be positive for Salmonella spp. and fifteen distinct serovars were detected. Clinically-important serovars predominated the isolates recovered, with almost all other identified serovars also implicated in human diseases. Antimicrobial susceptibility analysis of the 18 non-repetitive isolates showed that 14 isolates (77.8%) present drug resistance and seven isolates (38.9%) showed multidrug resistance phenotypes. High frequencies of resistance to streptomycin (66.7%), ampicillin (38.9%), and tetracycline (33.3%) were observed. Of particular concern, 22.2% of isolates were resistant to ciprofloxacin. The incidence of Salmonella serovars in the retail aquatic products and their high antimicrobial-resistance frequencies could constitute potential risks to public health. This study is valuable for supporting risk assessment, epidemiological investigation, and disease prevention. • Aquatic products in this study were found highly contaminated with Salmonella spp.. • Clinically-important serovars predominated the isolates recovered in this study. • All of the identified serovars have previously been implicated in human diseases. • The Salmonella isolates recovered showed high antimicrobial-resistance frequencies. • These antimicrobial-resistant Salmonella spp. are potential risks to human health. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is an important opportunistic pathogen in drinking water and monitoring P. aeruginosa strains is of importance for microbial safety. Here, prevalence of P. aeruginosa in drinking water samples (n = 206) from Guangdong of China were surveyed, and then P. aeruginosa were further characterized by DNA-based fingerprinting and detection of virulent factors. Result indicated that 25% of source water, 32.3% of carboned water, and 4.6% of finished water were positive for P. aeruginosa . Among 43 of P. aeruginosa isolates, ExoU , EcfX , ExoS , phzM , toxA , and lasB genes were present in 20.9%, 100%, 70%, 97.7%, 93% and 100% of isolates respectively. In addition, based on 90% similarity, P. aeruginosa were grouped into thirty-one ERIC types with discriminatory ability ( D ) of 97.34% and thirty-seven RAPD types using primer 208 or 272 independently with D of 99.22%. Some stains including PA4 and PA5 from 5# location; PA38, PA39 and PA40 from 42#; PA18 and PA19 from 7# showed the same types using both ERIC and RAPD typing methods. This study contributes to the valuable information about prevalence of P. aeruginosa in drinking water of Guangdong, and their characterization is helpful to trace the possible origins of P. aeruginosa through the drinking water chain. [ABSTRACT FROM AUTHOR]