Composition and density of microflora in the subungual space of the hand.

There were significant quantitative differences in the composition and density of microflora in different areas of the hands of 26 adult volunteers. The subungual spaces had an average log10 CFU of 5.39, compared with a range from 2.55 to 3.53 for other hand sites. In quantitative cultures from five subungual spaces in 26 subjects, coagulase-negative staphylococci were the dominant organisms, with Staphylococcus epidermidis, S. haemolyticus and S. hominis being the most frequently isolated species. Other bacteria recovered from subungual spaces included gram-negative bacilli in 42.3% of subjects, with Pseudomonas species composing 31.3% of this group, and coryneforms in 42.3% of subjects, with multiply resistant JK group coryneforms making up 12.5%. Yeasts were isolated from 69.0% of subjects sampled, with 51.3% of the yeasts identified as Candida parapsilosis. The subungual coagulase-negative staphylococci were susceptible to most antibiotics, with resistance to penicillin, ampicillin, and erythromycin detected in 23 to 38% of isolates.