1) 73 (61.8) 25 (55.5) 65 (64.3) 35 (67.3) 22 (59.4) 17 (70.8) 16 (69.5) *: p < 0.05 for CTX-M producers vs. non CTX-M producers. ‡: p < 0.05 for CTX-M-15 producers vs. non CTX-M producers. †: p < 0.05 for CTX-M-15 B2 producers vs. other phylogroup isolates with CTX-M-15. γ: p < 0.05 for B2 non-ST131 isolates vs. B2 ST131 isolates. Addiction systems of ESBL-carrying plasmids In total, 187 plasmid addiction systems were detected in plasmids encoding ESBLs (mean 1.29, range = 0-4 per recipient strain). pemKI, hok-sok, ccdAB and vagCD were the most frequently represented systems (Table 4). None of the plasmids harbored parDE or relBE and only 5 IncI1
plasmids carried the pndAC system. The plasmids Selleckchem IWR1 bearing CTX-M-15 had more addiction systems than those bearing other see more ESBLs (mean of 1.62 vs 0.73, respectively, P < 0.001). pemKI, vagCD and hok-sok were significantly more prevalent in CTX-M-15-carrying plasmids (Table 4). In addition, the mean number of addiction systems Selleck TPCA-1 was higher in CTX-M-15-carrying plasmids than in CTX-M-14 carrying ones.
Indeed, when the type of replicon was considered, the frequency of addiction systems was the highest in IncF plasmids, which were significantly associated to CTX-M-15-carrying plasmids, and IncI1 ones (mean: 1.90 IncF plasmids and 1.8 IncI1 vs 0.31 other plasmids, P < 0.001). IncA/C, IncN, IncHI2 were mostly devoid of addiction systems (Table 2). pemKI, hok-sok, ccdAB and vagCD systems were significantly more abundant in IncF plasmids, especially those carrying CTX-M-15 ESBLs (Table 4). When the type of IncF replicons was considered, we remarked that there were no clear PRKACG relationships between the numbers of the combination of the addiction systems and the different IncF replicon combinations. Nevertheless, the IncFII replicon alone was of the lowest frequency of addiction systems and lacked the ccdAB and vagCD systems. The FIA-FIB-FII replicon type showed the highest frequency of addiction systems (mean, 2.72),
followed by multi-replicon combinations comprising the FIA replicons (Table 4). Statistical analysis showed that vagCD is associated with FIA replicons. Moreover, 10 of the 16 (52.5%) CTX-M-15 plasmids carried by ST131 isolates were bearing the vagCD systems. In fact, the vagCD system was significantly associated to the CTX-M15-producing plasmids carried by ST131 isolates (P < 0.0001). Table 4 Nature and number of addiction systems according to ESBL type and replicon type identified in the recipient strains Addiction modules, n ESBL type n pemKI a ccdAB hok-sok b pndAC vagCD c Total Mean d All 144 84 29 51 5 18 187 1.29 TEM-26 2 2 0 0 0 0 2 SHV 39 12* 9 7* 0 3 31 0.79 SHV-2a 9 1 1 SHV-12 30 11 9 7 0 3 30 1.00 CTX-M 103 70 20 44 5 15 154 1.46 CTX-M-14 15 6 0 0 2 0 8 0.53 CTX-M-15 88 64 20 44 3 15 143 1.62 Replicon type n pemKI e ccdAB f hok-sok g pndAC vagCD h Total Meani A/C 5 0 0 0 0 0 0 N 4 0 0 0 0 0 0 L/M 14 9 0 0 0 0 9 0.64 IND 15 4 0 1 0 0 5 0.33 I1 5 2 0 0 5 2 9 1.