TABLE 5.

Virulence scores according to clbB or clbN status among blood and fecal isolates of Escherichia coli from veterans

Population (total no. of isolates)clbB- and clbN-positive isolatesclbB- and clbN-negative isolatesP valuea
No. of isolates in subgroupVirulence score (median [range])No. of isolates in subgroupVirulence score (median [range])
Total population
    Overall (131)5814.9 (8-21)734 (0-15)<0.001
        Fecal (69)2213.9 (8-18)472 (0-13.8)<0.001
        Blood (62)3615 (11-21)268.5 (0-15)<0.001
Group B2
    Overall (80)5814.9 (8-21)2210 (1-15)<0.001
        Fecal (38)2213.9 (8-18)168.3 (1-13.8)<0.001
        Blood (42)3615 (11-21)614 (12-15)0.003
  • a P values for comparison of virulence scores were determined by the Mann-Whitney U test.