Table 1.
L. innocua (n = 139) and L. monocytogenes (n = 81) isolate characteristics included in this study.
| PRODUCER | SOURCE | OCCURRENCE | TIME- FRAME |
ISOLATES (n) | PFGE PROFILE (ASCI/APAI) | CC f | ST (Serogroup) |
abcZ | bglA | cat | dapE | dat | ldh | lhkA | SSI-1 + g | SSI-1- h | SSI-2 i |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| L. monocytogenes (API profile 6-5-1-0) | |||||||||||||||||
| C | milk filter (PA) | sporc | once | 1 | M9[C] | 1 (I) | 1 (4b, 4d, 4e) | 3 | 1 | 1 | 1 | 3 | 1 | 3 | 0 | 1 | 0 |
| D | smear (PAL) | spor | once | 1 | M6[D] | 3 (I) | 3 (1/2b, 3b) | 4 | 4 | 4 | 3 | 2 | 1 | 5 | 1 | 0 | 0 |
| A | soft cheese (P) | spor | once | 1 | M8[A] | 7 (II) | 7 (1/2a, 3a) | 5 | 8 | 5 | 7 | 6 | 404 | 1 | 1 | 0 | 0 |
| E | smear (PAL) | spor | once | 1 | M4[E] | 398 (II) | 398 (1/2a, 3a) | 7 | 13 | 19 | 6 | 1 | 7 | 1 | 0 | 1 | 0 |
| A | smear (PAL) | spor | once | 1 | M12[A] | ST529 (III) | 529 (4b, 4d, 4e) | 25 | 73 | 82 | 96 | 45 | 211 | 67 | 0 | 1 | 0 |
| E | acid curd cheese (P)/smear (PAL) | rec b | 2 mo d | 2 | M1[E] | 59 (I) | 59 (1/2b, 3b) | 11 | 1 | 12 | 16 | 3 | 1 | 7 | 0 | 1 | 0 |
| C | swab (FCS) | recc | 1 yr d | 2 | M10[C] | 155 (II) | 155 (1/2a, 3a) | 7 | 10 | 16 | 7 | 5 | 2 | 1 | 1 | 0 | 0 |
| E | smear (PAL) | recc | 7 mo | 2 | M3[E] | 403 (II) | 403 (1/2a, 3a) | 7 | 7 | 10 | 4 | 5 | 24 | 1 | 1 | 0 | 0 |
| A/D | drain water (EL)/smear (PAL) | recc/spor | 11 yr/once | 11/1 | M11[A]=M7[D] | 14 (II) | 14 (1/2a, 3a) | 8 | 6 | 13 | 6 | 5 | 2 | 1 | 1 | 0 | 0 |
| E | acid curd cheese (P)/culture (PA)/environment (NFCS) | rec b | 1 mo | 3 | M2[E] | 121 (II) | 121 (1/2a, 3a) | 7 | 6 | 8 | 8 | 6 | 37 | 1 | 0 | 0 | 1 |
| B/D/E | smear (PAL) | recc/recb/spor | 7 yr/4mo/once | 47/7/1 | M5[B]=M5[D]=M5[E] | 121 (II) | 121 (1/2a, 3a) | 7 | 6 | 8 | 8 | 6 | 37 | 1 | 0 | 0 | 1 |
| L. innocua (API profile 7-5-1-0) | |||||||||||||||||
| C | smear (PAL) | spor | once | 1 | IN10[C] | ST1596 | 1596 | 26 | 21 | 33 | 33 | 48 | 213 | 216 | 0 | 0 | 1 |
| C | cheese (P) | spor | once | 1 | IN18[C] | ST530 | 530 | 28 | 62 | 40 | 97 | 45 | 214 | 53 | 0 | 0 | 1 |
| A | smear (PAL) | spor | once | 1 | IN12[A] | 140 | 637 | 28 | 23 | 33 | 35 | 23 | 192 | 16 | 0 | 0 | 1 |
| C | floor water (NFCS) | spor | once | 1 | IN15[C] | 140 | 637 | 28 | 23 | 33 | 35 | 23 | 192 | 16 | 0 | 0 | 1 |
| E | smear (PAL) | rec b | 4 mo | 2 | IN2[E] | 140 | 637 | 28 | 23 | 33 | 35 | 23 | 192 | 16 | 0 | 0 | 1 |
| E | smear (PAL) | spor | once | 1 | IN4ST[E] | 600 | 603 | 36 | 21 | 40 | 108 | 65 | 243 | 81 | 0 | 0 | 1 |
| C/E | hard cheese (P)/acid curd cheese (P)/smear (PAL) environment (NFCS | spor/recc | once/5.6 yr | 1/12 | IN4[C]=IN4[E] /n. t.e | 600 | 603a | 36 | 21 | 40 | 108 | 65 | 243 | 81 | 0 | 0 | 1 |
| A/C/D/E | grating cheese (P)/smear, brine(PAL)/floor water (EL) | rec c/rec c/rec c/rec c | 1 yr/6.8yr/6.2yr/1yr | 2/22/68/2 | IN5[A]=IN5[C]=IN5[D]=IN5[E]/n. t. | ST1597 | 1597 a | 36 | 23 | 30 | 96 | 195 | 19 | 16 | 0 | 0 | 1 |
| A | smear (PAL) | spor | once | 1 | IN9[A] | 448 | 448 | 65 | 21 | 40 | 33 | 45 | 170 | 53 | 0 | 0 | 1 |
| C | raw milk (RM) | spor | once | 1 | IN14[C] | ST1598 | 1598 | 79 | 21 | 33 | 97 | 20 | 356 | 58 | 0 | 0 | 1 |
| A | smear (PAL) | spor | once | 1 | IN16[A] | ST43 | 43 | 143 | 21 | 40 | 167 | 55 | 307 | 16 | 0 | 0 | 1 |
| C | hard cheese (P) | spor | once | 1 | IN21[C] | ST43 | 43 | 143 | 21 | 40 | 167 | 55 | 307 | 16 | 0 | 0 | 1 |
| A/C/D | soft cheese (P)/smear (PAL) | rec b/spor/rec b | 5 mo/once/4mo | 02.01.2003 | IN6[A]=IN6[C]=IN6[D] | ST1599 | 1599a | 143 | 95 | 30 | 96 | 55 | 180 | 16 | 0 | 0 | 1 |
| L. innocua (API profile 7-1-1-0) | |||||||||||||||||
| E | acid curd cheese (P)/enrichment (PAL)/drain water (EL) | rec c | 6 mo | 3 | IN1[E] | ST1595 | 1595 a | 25 | 73 | 237 | 130 | 55 | 19 | 16 | 0 | 0 | 1 |
| D | semi-hard cheese (P) | spor | once | 1 | IN8[D] | ST1482 | 1482 | 26 | 21 | 40 | 33 | 45 | 19 | 53 | 0 | 0 | 1 |
| C | cheese (P) | spor | once | 1 | IN17[C] | ST605 | 605 | 36 | 21 | 30 | 35 | 45 | 69 | 17 | 0 | 0 | 1 |
| C | cheese (P) | spor | once | 1 | IN20[C] | ST605 | 605 | 36 | 21 | 30 | 35 | 45 | 69 | 17 | 0 | 0 | 1 |
| C | cheese (P) | spor | once | 1 | IN19[C] | ST1087 | 1087 | 191 | 21 | 184 | 110 | 45 | 356 | 16 | 0 | 0 | 1 |
| C | smear (PAL) | rec c | 1.3 yr | 2 | IN7[C] | ST1085 | 1085 a | 188 | 157 | 182 | 223 | 136 | 353 | 148 | 0 | 0 | 1 |
| E | acid curd cheese (P) smear (PAL) | rec c | 6 mo | 4 | IN3[E] | ST1601 | 1601 a | 250 | 140 | 73 | 223 | 136 | 341 | 214 | 0 | 0 | 1 |
| L. innocua (API profile 7-5-3-0) | |||||||||||||||||
| A | smear (PAL) | spor | once | 1 | IN13[A] | ST1600 | 1600 | 40 | 62 | 30 | 33 | 55 | 356 | 17 | 0 | 0 | 1 |
| A | smear (PAL) | spor | once | 1 | IN11[A] | ST1008 | 1008 | 173 | 140 | 173 | 208 | 136 | 341 | 138 | 0 | 0 | 1 |
a sporadically isolated Listeria spp. genotypes; b recurrently isolated Listeria spp. genotypes; c recurrently isolated Listeria spp. genotypes over a period of ≥6 months defined as persistent; d mo, month; yr, year; e non-typable; f CC, clonal complexes; genetic lineages are provided in brackets; g SSI-1+, stress survival islet positive strains; h SSI-1-, stress survival islet negative strains, F2365_0481 homologous gene; i SSI-2, stress survival islet 2 positive genotypes. Abbreviations: Product associated liquids (PAL; smear, brine), product associated samples (PA, culture, and enrichment), raw material (RM), food contact surfaces (FCS), non-food contact (NFCS) surfaces, and environmental (E) liquid samples (floor and drain water). Red marked housekeeping genes are present in L. monocytogenes genetic lineage III and L. innocua.