Genetic characteristics were evaluated for all MRSA isolates and all MSSA isolates from the nasal

swabs, and from the water and sand samples from the small pool. Due to the large number of S. aureus isolates from the large pool, genetic characterization was conducted on a representative set of the MSSA isolates from each large pool water collection and choosen to include a subset of all colony morphology, gross pigmentation and RBC hemolysis type present in each set. All MSSA collected from the small pool water samples BB-94 cell line from the single colonized pediatric participant were analyzed. Statistical analyses Data analyses (including Pearson Correlations, Student T-Tests, and Sum Rank Tests) were performed using Microsoft Excel 2003 and Sigmaplot 11. Results Off shore water quality The physical-chemical characteristics of the source water taken off shore were typical of marine waters in subtropical environments (salinity = 34 psu, pH = 7.9, temperature = 31°C). The concentrations of S. aureus in the source water samples prior

to human exposure were primarily below the detection limit of 1 CFU/100 mL. Only 1 of 8 (13%) samples measured at the detection limit of 1 CFU/100 mL using the MF method with learn more selection on CHR. Two of 22 (9.1%) samples measured at 10 CFU/100 mL using selection on BP. The concentrations of S. aureus in the pool before versus after bathing differed by two-orders-of-magnitude indicating that background VX-680 supplier levels of S. aureus in the source water was insignificant. MRSA was Florfenicol not detected from any source water samples. Overall, these results are consistent with earlier studies that showed that the offshore waters at the study site are characterized

by low concentrations of viable indicator bacteria [17, 18, 24]. S. aureus released by bathers In the large pool study with adults, the total quantities of S. aureus released per person were lower (105) by about an order of magnitude, in the first two bathing cycles as compared to Elmir et al. [17] who reported releases on the order of 106 per person (Table 1). The results appeared to converge for the last two cycles at about 105 CFU/person released. On average for all four cycles and for both groups, S. aureus counts were 6.3 × 105 CFU/person from BP selection which was 40% higher than 3.8 × 105 CFU/person from CHR selection. Table 1 Colony forming units of S. aureus shed per adult   Group I Group II Average   Cycle (BP) (CHR) (BP) (CHR) (BP) (CHR) (CHR) 1 1.3 × 106 8.1 × 105 *1.4 × 105 BDL 7.1 × 105 4.1 × 105 6.1 × 106 2 8.3 × 105 8.1 × 105 4.6 × 104 BDL 4.4 × 105 4.1 × 105 3.9 × 106 3 9.1 × 105 4.2 × 105 *1.0 × 106 *4.3 × 105 9.6 × 105 4.3 × 105 1.3 × 106 4 3.6 × 105 8.1 × 104 *4.3 × 105 *4.5 × 105 3.9 × 105 2.6 × 105 6.8 × 105 Average 8.4 × 105 5.3 × 105 4.1 × 105 2.2 × 105 6.3 × 105 3.8 × 105 3.0 × 106 Standard Deviation 3.8 × 105 3.5 × 105 4.4 × 105 2.5 × 105 2.7 × 105 7.6 × 104 2.5 × 106 * Water samples where MRSA was detected.