TABLE 3.
Distribution of inlA genotypes across strain source
| Isolate source | No. (%) of strains witha: |
Bonferroni-corrected P valueb | |||
|---|---|---|---|---|---|
| Truncated inlA with: |
Full-length inlA | ||||
| PMSC 4 | PMSC 7 | PMSC 12 | |||
| Animal clinical case | 0 | 0 | 0 | 21 (100) | 0.0612 |
| Fecal samples from asymptomatic animals | 0 | 0 | 0 | 23 (100) | 0.0351 |
| Farm environment | 0 | 0 | 0 | 30 (100) | 0.0034 |
| Food environment | 3 (30) | 1 (10) | 0 | 6 (60) | 1.00 |
| Urban or natural environment | 1 (10) | 0 | 0 | 9 (90) | 1.00 |
| Food | 26 (45) | 1 (2) | 1 (2) | 29 (51) | <0.0001 |
| Human clinical case | 7 (18) | 0 | 1 (2) | 32 (80) | 1.00 |
| Total | 37 (19) | 2 (1) | 2 (1) | 150 (79) | |
Of the total of 368 isolates, 228 isolates were screened here for inlA PMSCs by a multiplex SNP genotyping assay; inlA PMSC data for the remaining 140 isolates were obtained from previous publications (15, 16). This table shows the data for 191 isolates that were classified as epidemiologically unrelated strains (as described in Materials and Methods). Isolates were classified into those carrying (i) truncated inlA (indicating the presence of an inlA PMSC) or (ii) full-length inlA.
P value for Fisher's exact tests determining whether the inlA PMSC genotype (full length or truncated) was associated with a given isolate source. Fisher's exact test of an overall 2 by 7 table (inlA genotype by isolate source) indicated that the inlA PMSC genotypes differed between sources (P < 0.001).