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. 2015 Apr 10;59(5):2909–2913. doi: 10.1128/AAC.04763-14

TABLE 1.

Characteristics and amino acid changes in MgrB, PhoP, PhoQ, and PmrB in colistin-resistant strains

Strain Source Colistin usage in VGH MIC Capsular type MLST mRNA relative fold change (mean ± SD)
 Insertion sites in the mgrB regiona MgrBb
 PhoPb
 PhoQb
 PmrBb
pmrHc pmrKd mgrBe 28 48 3 86 26 150 258 157 256 280
Col4 Blood Yes >2,048 K64 ST11 9.38 ± 0.30 Gly
Col7 Blood Yes 1,024 K64 ST11 4.61 ± 0.16 Gly
Col20 Sputum 2,048 K64 ST11 4.41 ± 0.08 Gly
Col21 Sputum Yes 512 K64 ST11 2.61 ± 0.14 Gly
Col22 Sputum 2,048 K64 ST11 2.73 ± 0.02 Gly
Col36 Sputum Yes 2,048 K64 ST11 2.92 ± 0.13 Gly
Col44 Sputum 512 K64 ST11 5.66 ± 0.05 Gly
Col49 Urine 128 K64 ST11 10.92 ± 0.94 Tyr Gly Gly
Col38 Urine 64 K64 ST11 25.40 ± 0.67 Pro
Col13 Sputum Yes 128 K64 ST11 5.33 ± 0.04 Deletionf
Col25 Bile 64 K64 ST11 5.35 ± 0.14 IS10R in coding region (+68 to +76)
Col27 Sputum Yes 128 K64 ST11 14.68 ± 0.97 0.07 ± 0.02 IS10R in promoter region (−27)
Col33 Sputum Yes 128 K64 ST11 16.52 ± 1.12 IS10R in coding region (+68 to +76)
Col11 Sputum Yes 64 K24 ST15 2.16 ± 0.06 0.01 ± 0.002 IS5-like in promoter region (−8)g
Col37 Pus Yes 16 K24 ST15 6.17 ± 0.13 Tyr
Col40 Pus Yes 64 K24 ST15 9.04 ± 0.03 Tyr Phe
Col23 Urine Yes 32 K54 ST15 2.01 ± 0.02 Pro
Col28 Urine >2,048 K54 ST29 5.9 ± 0.13 Phe
Col6 Urine Yes 64 K62 ST48 3.16 ± 0.16 Leu Pro Leu
Col14 Blood Yes 128 K47 ST11 2.83 ± 0.12 Deletionf
Col19 Urine Yes 64 K28 ST37 3.69 ± 0.06 0.05 ± 0.004 IS10R in promoter region (−27)
Col26 Sputum Yes 32 K3 ST13 17.97 ± 0.44 0.19 ± 0.02 IS5-like in promoter region (−34)g
Col32 Sputum 64 K1 ST23 21.02 ± 1.85 IS5-like in coding region (+75 to +83)g
Col24 Sputum 32 Unknown K-type ST421 0.22 ± 0.01 10.63 ± 0.69 Tyr
Col31 Sputum Yes 128 Unknown K-type ST421 0.42 ± 0.07 12.72 ± 0.02 0.01 ± 0.001 IS5-like in promoter region (−35)g
Col5 Pus 8 KN3 ST11-like 0.34 ± 0.02 4.34 ± 1.31 Gly
a

The nucleotide position aligned with genomic DNA of NTUH-K2044 and IS element-inserted sites.

b

The amino acid positions of mutations in MgrB, PhoP, PhoQ, and PmrB.

c

The pmrH mRNA relative fold changes (against NTUH-K2044 strain) of the other 7 colistin-susceptible strains were 0.6 ± 0.02, 1.11 ± 0.02, 1.68 ± 0.11, 0.59 ± 0.04, 1.65 ± 0.07, 0.37 ± 0.01, and 0.9 ± 0.04.

d

The pmrK mRNA relative fold changes (against NTUH-K2044 strain) of the other 7 colistin-susceptible strains were 4.74 ± 0.69, 0.79 ± 0.28, 1.14 ± 0.51, 6.98 ± 0.82, 0.85 ± 0.08, 3.77 ± 0.78, and 2.01 ± 0.18.

e

The mgrB mRNA relative fold changes (against NTUH-K2044 strain) of the other 7 colistin-susceptible strains were 0.41 ± 0.06, 1.19 ± 0.17, 1.67 ± 0.64, 0.52 ± 0.11, 1.04 ± 0.13, 0.51 ± 0.03, and 0.66 ± 0.11.

f

No PCR product was detected, and the deletion site is not known.

g

The IS5-like elements of Col11, Col26, Col32, and Col31 were 95%, 99%, 95%, and 95% identical to the IS5 element.