Stargazer
Contributor
This letter printed in the American Society of Microbiology journal "Microbe" last December is a wake-up call about hygiene and rinse tanks......about time someone looked into this issue. See link below to original Microbe 2007 vol. 2:#12, p. 577). Text of letter:
Over the years, we have heard some people complain of various illnesses after scuba diving trips. On such trips, gear (including wet suits, booties, buoyancy control devices, regulators with mouthpieces, etc.) is typically rinsed in large, communal tanks. We wondered if these communal rinse tanks could harbor microorganisms that could be passed among divers during equipment rinses. Literature searches did not identify any studies investigating this topic.
During four days in June 2007, water samples were collected from two rinse tanks at a dive facility on Roatan, Honduras. The two rinse tanks were emptied each morning about 8:00 AM and refilled with fresh (nonsalt) water). Most diving was done from boats, which returned about noon and 4:30 PM, following morning and afternoon dives, respectively. Water samples were obtained daily at 8:30 AM, 12:30 PM, and 4:30 PM, in sterile Eppendorf tubes which were stored in a refrigerator until the day of departure. On the day of departure, samples were packed in a suitcase and returned to a refrigerator about 12 hour later. The following day, 50-_l aliquots were spread on Terrific broth-agar plates, incubated at 37oC overnight, and then visually examined for colonies and photographed.
Our hypothesis was that the 8:30 AM samples, taken before equipment was rinsed, would be relatively clean and that samples taken later in the day would show more contamination as more equipment was rinsed. However, we found that all water samples produced many colonies, and that at times the 8:30 AM samples produced more colonies than samples collected later in the day. No colonies appeared on control plates not exposed to water samples or on plates exposed to tap water. (Pictures of these plates can be viewed online at WVU Health Sciences Center som/bmp/miller.aspclick Rinse Tank Data link under the topic Research, then click Rinse Tanks Powerpoint Presentation). On several days, only one rinse tank was filled or in the process of being filled for the 8:30 AM samplings. From each plate, several colonies with different morphologies were subcultured in Terrific broth overnight and observed under a dark-field microscope. Multiple types of bacteria were detected, based on different morphology/swimming patterns; videos of different colonies can be viewed by following the links indicated above.
While we do not yet know the source of microbes in the rinse tanks, nor if any of the organisms in the rinse tanks are pathogenic, it is clear that these communal rinse tanks do harbor many microbes that would come in contact with divers mouthpieces, potentially spreading pathogens between divers. We recommend that divers rinse their regulators separately or consider spraying mouthpieces with a safe disinfectant, such as 70% ethanol.
Authors: Michael R. Miller, M. A. Motaleb, West Virginia University, Morgantown
Microbe Magazine
Over the years, we have heard some people complain of various illnesses after scuba diving trips. On such trips, gear (including wet suits, booties, buoyancy control devices, regulators with mouthpieces, etc.) is typically rinsed in large, communal tanks. We wondered if these communal rinse tanks could harbor microorganisms that could be passed among divers during equipment rinses. Literature searches did not identify any studies investigating this topic.
During four days in June 2007, water samples were collected from two rinse tanks at a dive facility on Roatan, Honduras. The two rinse tanks were emptied each morning about 8:00 AM and refilled with fresh (nonsalt) water). Most diving was done from boats, which returned about noon and 4:30 PM, following morning and afternoon dives, respectively. Water samples were obtained daily at 8:30 AM, 12:30 PM, and 4:30 PM, in sterile Eppendorf tubes which were stored in a refrigerator until the day of departure. On the day of departure, samples were packed in a suitcase and returned to a refrigerator about 12 hour later. The following day, 50-_l aliquots were spread on Terrific broth-agar plates, incubated at 37oC overnight, and then visually examined for colonies and photographed.
Our hypothesis was that the 8:30 AM samples, taken before equipment was rinsed, would be relatively clean and that samples taken later in the day would show more contamination as more equipment was rinsed. However, we found that all water samples produced many colonies, and that at times the 8:30 AM samples produced more colonies than samples collected later in the day. No colonies appeared on control plates not exposed to water samples or on plates exposed to tap water. (Pictures of these plates can be viewed online at WVU Health Sciences Center som/bmp/miller.aspclick Rinse Tank Data link under the topic Research, then click Rinse Tanks Powerpoint Presentation). On several days, only one rinse tank was filled or in the process of being filled for the 8:30 AM samplings. From each plate, several colonies with different morphologies were subcultured in Terrific broth overnight and observed under a dark-field microscope. Multiple types of bacteria were detected, based on different morphology/swimming patterns; videos of different colonies can be viewed by following the links indicated above.
While we do not yet know the source of microbes in the rinse tanks, nor if any of the organisms in the rinse tanks are pathogenic, it is clear that these communal rinse tanks do harbor many microbes that would come in contact with divers mouthpieces, potentially spreading pathogens between divers. We recommend that divers rinse their regulators separately or consider spraying mouthpieces with a safe disinfectant, such as 70% ethanol.
Authors: Michael R. Miller, M. A. Motaleb, West Virginia University, Morgantown
Microbe Magazine
