Prevalence of multiple-antibiotic resistance in Pseudomonas aeruginosa isolated from hospitalized patients and from the discharge of wastewaters from both hospitals and communities

Abstract

The aim of this study was to establish the prevalence of multiple-antibiotic resistance in Pseudomonas aeruginosa isolated from hospitalized patients and from wastewaters, with and without treatment, discharged from eight hospitals and eight communities in Bangkok. A total of 320 wastewater samples were examined for the quantitative presence of Pseudomonas aeruginosa. Significance differences (P< 0.05) in the number of samples and total numbers of organism per positive sample were observed between the treated and untreated samples or between the hospital and community wastewater samples. Pseudomonas aeruginosa was detected in 35% of treated compared to 86.2% of untreated wastewater from the hospitals; and 57.5% of treated compared to 82.5% of untreated wastewater from the communities. Untreated hospital wastewaters gave the highest count. The resistance rates to 8 antibiotics were determined in 200 Ps. aeruginosa strains isolated from wastewaters, and 200 strains from hospitalized patients. There was no significant differences in resistance rates and resistance patterns between hospitalized patient and hospital wastewater strains (P>0.05). The prevalence of multiple resistance strains were significantly higher in strains from either hospitalized patients (51%) or hospital wastewaters (53%) than from community wastewaters (11%) (P<0.05). In conclusion, the study emphasizes the significance of hospital wastewater which, without effective treatment, may serve as reservoirs of multiple resistant Ps. aeruginosa which may spread into water environment and become a serious threat to public health. Surveillance and prudent use of antibiotics in the hospitals as well as the effective treatment of wastewater to reduce antibiotic-resistant bacteria are urgently needed for environmental and public health protection.