Disinfectants are effective in controlling bacterial contaminants in swimming pool and pond waters in Lahore City, Punjab, Pakistan

Swimming pools and pond waters may contain microbial contamination that could be a source of public health hazards. Waterborne bacteria from human or animal excrements or the environment can contaminate swimming pools and ponds. Unhygienic practices at pools, along with stormwater, sewage, and agricultural runoff, can all lead to contamination, indicating the need for monitoring bacterial levels in both swimming pools and pond waters. Therefore, the present study was designed to evaluate the microbial quality of swimming pool and pond waters in Lahore City, Punjab, Pakistan. For this purpose, 10 swimming pools and 10 ponds in the study area were selected. The microbial quality of swimming pool and pond waters was tested by bacterial plate counts and the identification of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa by both biochemical tests and polymerase chain reaction. Next, the efficacy of sodium hypochlorite, silver hydrogen peroxide, and polyhexanide was evaluated by a quantitative suspension test applied to the bacterial isolates. The total aerobic plate counts of all swimming pool waters were < 1 CFU/mL, while the total enteric coliforms in only half of the pools were < 1 CFU/100 mL. Total aerobic plate counts of pond waters ranged from ~ 427–1777 CFU/mL, while total enteric coliforms were ~ 197–1737. Biochemical tests and PCR demonstrated the presence of S. aureus, and P. aeruginosa in the tested swimming pools and ponds. The S. aureus was present in 20% of the swimming pools and ponds. The P. aeruginosa was observed in 20% of swimming pools and 40% of ponds. The E. coli was absent in 100% of the swimming pools but present in 100% of ponds. The standard dilutions of sodium hypochlorite, silver hydrogen peroxide, and polyhexanide demonstrated high antimicrobial activity against bacteria isolated from swimming pools and ponds at all contact times suggesting the efficacy of these disinfectants for controlling bacterial contamination in swimming pools and ponds.