The pollution survey of Pseudomonas aeruginosa in mineral water and spring water and the analyses of virulence genes and antibiotic resistance of the isolates

Abstract:

[Objective] This experiment was made to obtain a preliminary understanding of pollution of Pseudomonas aeruginosa in the production process of mineral water and spring water. Pathogenicity and antibiotic resistance of P. aeruginosa of mineral water and spring water were analyzed. [Methods] This experiment based on 108 samples from 36 mineral water and spring water factories in 9 provinces. According to the methods for examination of drinking natural mineral water (GB/T8538-2008), the pollution rates and pollution levels of P. aeruginosa had been obtained. The tests of virulence gene and antibiotic resistance were tested on collected P. aeruginosa isolates. [Results] The pollution rates of source water, activated carbon filtered water and finished products of mineral water were 16.7%, 16.7%, 0 respectively. The pollution levels of source water, activated carbon filtered water and finished products of mineral water were 3.7, 2.0, 0 CFU/250 mL respectively. The pollution rates of source water, activated carbon filtered water and finished products of spring water were 66.7%, 83.3% and 5.6% respectively. The pollution levels of source water, activated carbon filtered water and finished products of spring water were 5.1, 7.3, 2.0 CFU/250 mL respectively. The virulence gene and antibiotic resistance tests of 36 P. aeruginosa isolates showed that the detection rates of exoU, exoS, phzM, toxA and lasB were 25.0%, 75.0%, 100%, 88.8%, 100% respectively; 36 P. aeruginosa strains were sensitive to 14 kinds of antibiotics which were selected according National Committee for Clinical Laboratory Standards of The United States of America. [Conclusion] The pollution rates of source water, activated carbon filtered water and finished products of spring water were significantly higher than mineral water. Both the pollution levels of 2 kinds of water samples were relatively low and there was no greater than 40.0 CFU/250 mL of the sample. The activated carbon filtered water of spring water was the highest pollution rate among all samples, which indicated that most of the factories had some microbial pollution in the activated carbon filter link. The high detection rates of virulence genes, including exoU, exoS, phzM, toxA and lasB in 36 strains of collected P. aeruginosa were analysed. All 36 isolates of collected P. aeruginosa were sensitive to 14 kinds of antibiotics.

Key words:Mineral water, Spring water, Pseudomonas aeruginosa, Virulence gene, Antibiotic resistance