highly significantP < 0.01
Distribution of organisms according to study and control groups showed that by applying Z-test for difference between two proportions, there was a highly significant difference between proportions of organisms SM, Pseudomonas aeruginosa (PA) and Staphylococcus aureus (SA) in study and control group (i.e., P < 0.01) and significant for organisms, namely, Klebsiella (K) and non-hemolytic streptococci (i.e., P < 0.05) and not significant for organism Enterobacter (E) (i.e., P > 0.05) [ Table 2 ].