Prevalence of Klebsiella pneumoniae strains producing carbapenemases and increase of resistance to colistin in an Italian teaching hospital from January 2012 To December 2014

Table 5 MLST analysis on pairs of CoS and CoR strains obtained from the same patient. Time to switch is intended as the time-interval between the first CoS strain isolated from a clinical sample and the first CoR strain isolated from the same patient

	Strains with Stable ST
Patient	ST of the first CoS strain isolated	Sample type	Sample type of first clinical CoS	ST of CoR strain isolated	Sample type	Time to switch from CoR to CoS (days)
1	554	SRS	Arterial catheter	-	bronchial aspirate	36
2	512	SRS	skin swab	-	urine	26
3	307	SRS	skin swab	-	skin swab	42
4	512	SRS	skin swab	-	SRS	123
5	512	SRS	drainage fluid	-	drainage fluid	28
6	512	urine	urine	-	urine	17
7	512	SRS	bronchial aspirate	-	SRS	74
8	1543	SRS	-	-	SRS	50
9	512	SRS	bronchial aspirate	-	bronchial aspirate	31
10	512	SRS	bronchial aspirate	-	bronchial aspirate	6
11	554	SRS	-	-	bronchial aspirate	na
12	512	SRS	bronchial aspirate	-	blood	24
13	258	SRS	urine	-	urine	8
						Median
						29.5 days
	Switched ST
Patient	ST of the first CoS strain isolated	Sample type	Sample type of first clinical CoS	ST of CoR strain isolated	Sample type	Time to switch from CoR to CoS (days)
14	15	SRS	urine	512	SRS	167
15	554	urine	urine	512	SRS	67
16	258¹	SRS	skin swab	512	SRS	34
17	554	SRS	arterial catheter	1733 (554 SLV)	drainage fluid	54
						Median:
						60.5 days

¹ simultaneous isolation of a ST258 CoS strains and a ST512 CoR strain from the same sample at the first detection”
CoR colistin resistant, CoS colistin susceptible, MLST Multilocus sequence typing, na not applicable, SLV single locus variant, SRS surveillance rectal swab, ST sequence typing

ISSN: 1471-2334