Evaluation of MLVA for epidemiological typing and outbreak detection of ESBL-producing Escherichia coli in Sweden

Table 2 Comparison of the numbers of types generated by the various MLVA and PFGE. The numbers of types generated by the various MLVA using three (GECM-3), seven (GECM-7), or ten (GECM-10) loci, respectively, in comparison with that of PFGE using >80% similarity index for the designation of types, for the typing of 116 ESBL-E. coli isolates belonging to either the ST131-O25b linage (n = 34) or not

Number of isolates within a type	GECM-3		GECM-7		GECM-10		PFGE
Number of isolates within a type	Non-O25b	O25b	Non-O25b	O25b	Non-O25b	O25b	Non-O25b	O25b
Singleton	22	0	38	0	44	0	60^a	6^b
2–4	11	1	11	1	11	1	9^b	7
5–9	2	0	3	0	2	0	0	0
≥10	1	2	0	2	0	2	0	1
Total number of types	36	3	52	3	57	3	69	14
Simpsons index of diversity (CI 95%)	0.96 (0.94–0.98)	0.59 -	0.98 (0.97–0.99)	0.59 -	0.99 (0.98–0.99)	0.59 -	1.0 (0.99–1.0)	0.89 -

^aIsolates non typeable by PFGE (n = 4) included, each with an individual designation and thus accounted for as singeltons. ^bPFGE type JB is included in both the non-O25b and O25b isolates (however both ST131), so it is listed in both columns

ISSN: 1471-2180