Gram-positive bacteria were less frequently recovered from lower lid swabs from the test group ( 39.6 % vs. 66.0 % [ p < 0.001 ] , test vs. control , respectively ) or from contact lens samples ( 1.9 % vs. 10.5 % [ p = 0.015 ] , test vs. control , respectively ) , but there was no difference in gram-negative bacteria ( GNB ) .