Occurrence, Persistence, and Virulence Potential of Listeria ivanovii in Foods and Food Processing Environments in the Republic of Ireland

Table 1

Occurrence and pulsed field gel electrophoresis characterisation of isolates from L. ivanovii positive samples, listed according to processing facility, sampling month, sample type, and pulsotype, for example, T1. Empty white boxes indicate no L. ivanovii detected in submitted samples. “—” indicates nonsubmission of samples during that sampling month.

Facility number	% positives	March 13		May 13		July 13		September 13		November 13		January 14		March 14
		Environment	Foods	Environment	Foods	Environment	Foods	Environment	Foods	Environment	Foods	Environment	Foods	Environment	Foods
Dairy
1	13.1							T3		T3		T3		T3
2	0
3	0
4	0
5	0
6	2.4							T5				—	—
7	0	—	—							—	—
8	0
9	0
10	4					T2								T4
11	0	—	—			—	—	—	—			—	—
12	4.5	T1				T1		—	—			—	—
13	0
14	0
15	0									—	—	—	—	—	—
16	0
17	0	—	—	—	—	—	—					—	—
18	0	—	—	—	—	—	—							—	—
Meat
19	0	—	—					—	—	—	—	—	—	—	—
20	0
21	0
22	1.8										T6
23	0	—	—	—	—	—	—
24	0	—	—	—	—	—	—
25	0	—	—	—	—	—	—			—	—	—	—
26	0			—	—	—	—	—	—	—	—	—	—	—	—
27	0									—	—	—	—
28	0									—	—
29	0			—	—					—	—	—	—
30	0									—	—
Seafood
31	0							—	—
32	0							—	—
33	0					—	—	—	—
34	0
35	0													—	—
36	0
37	12.5	—	—	—	—	—	—	—	—	T4		—	—	—	—
38	0	—	—	—	—	—	—
Vegetable
39	0
40	0							—	—	—	—	—	—	—	—
41	0
42	0					—	—
43	0
44	0											—	—
Miscellaneous
45	0
46	0							—	—	—	—	—	—
47	0	—	—	—	—	—	—
48	0									—	—

Pulsotypes which persist in a single facility (isolated at least 6 months apart) are in bold.