This was seen when the large pool sample water (for Group II) was positive for MRSA only when MRSA was found in the anterior nares of participants who bathed in that water; and the majority of these organisms were shown to have the same genetic characteristics as the colonizing MRSA. Direct shedding was also observed when the single known nasally colonized toddler shed into the water sample in the small pool study. The results reported here confirm that S. see more aureus are shed by colonized adults
and toddlers into the water column. This is supported by the results from both adults and toddlers in the separate pool studies. In the large pool studies, MSSA and MRSA were isolated when the participants were known only to be colonized with MRSA only (Group II); however, although only 1 toddler was shown to be colonized by nares sampling method, 10 toddlers shed MSSA. As a result of these findings, we hypothesize that both adults and toddlers are likely colonized with S. aureus, in particular MSSA, in other areas of the body, and that these locations
contribute to bacterial shedding when exposed to water. This observation is consistent with clinical observations showing that about one third of MRSA-infected patients were not nasally colonized , with alternate colonization sites including skin  and throat . Both the large pool study and the small pool study demonstrated that sand played a relatively small role JNJ-26481585 mw in S. aureus shedding. In the small pool study during the single bathing cycle, sand accounted for less than 1% of shedding. Elmir et al.  also found that sand accounted for roughly 3.7% of the enterococci contribution in the first bathing cycle for the small pool study. For the large pool study, an increase in S. aureus shedding was observed when participants were exposed to sand between the second and third bathing cycles, but the impacts were less pronounced for S. aureus as compared to enterococci shedding as observed in prior studies . Increased numbers of S. aureus shed in the third cycle could be associated with sand exposures; however, the ultimate
source of the S. aureus in the sand is unknown, and may be associated with naturally existing S. aureus and/or 4��8C from direct shedding from humans to the sand. Because of the differences in the designs of the large pool study (adults) and the small pool study (toddlers), direct comparison of the amount of shedding between toddlers and adults in this study is limited. Nevertheless, we compared the numbers of S. aureus shed by adult and toddlers, keeping these limitations in mind. The average of S. aureus shed by adults during the four Selleckchem Silmitasertib cycles in the large pool (n = 8 composites of 10 people) was 6.3 × 105 CFU/person, and by toddlers (n = 14) was 4.3 × 104 CFU/person in the small pool. In this comparison, adults shed 13 times more S. aureus than toddlers on average (75 times on median).