Pseudomonas aeruginosa isolated from otitis externa associated with recreational waters in some public swimming pools in Tehran

Background: Pseudomonas aeruginosa is the most significant bacteria capable of multiplying in water especially in recreational waters. This bacterium is also the most commonly bacterial pathogen in ear infections. Although the bacterium is infrequently found in the normal ear, but the users of swimming pools may be at risk of acquiring disease. Patients and methods: The bacteriological quality and health risk of the water of eleven public outdoor and indoor swimming pools in East and North-East of Tehran was assayed. Useful information was recorded at the time of sampling. Samples tested for aerobic colony count, coliforms, Escherichia coli and P. aeruginosa according to the standard method. Ear swabs were collected from 179 users with a history of ear problems during the previous two weeks. An adequate control group was chosen randomly from those who never used the investigated pools. Results: P. aeruginosa was isolated from 9 (81.8%) of the pools. P. aeruginosa was the only bacterium grew in 7 (63.6%) swimming pools, while in the other 2 (18.2%) swimming pools high rates of total bacterial count, total coliforms and fecal coliform counts were also found besides P. aeruginosa. Meanwhile, P. aeruginosa was isolated from the ear swabs of 142 (79.3%) swimming pool users, as compared to 4% of the controls. Conclusion: Results revealed that otitis externa was strongly associated with swimming in pools, due to P. aeruginosa. Furthermore, contamination of the swimming pools with P. aeruginosa and often the chlorination process could not remove the pollution, especially when high numbers of people led to overuse of the pools, hence, more strict bathing water standards should be met in the public swimming pools in the city