Stenotrophomonas maltophilia Quinolone Protection Proteins (SmQnr)

Stenotrophomonas maltophilia is a non-fermentative Gram-negative bacillus found commonly in the environment but also responsible for a diverse range of infections in the immunocompromised and critically ill. The organism frequently exhibits multi-drug resistance including to quinolone antibiotics. Pentapeptide repeat proteins of the Qnr family, have been found in a number of bacteria, and are thought to contribute to resistance by protection of the DNA targets from quinolone inhibition. In S. maltophilia the genes encoding Qnr proteins (Smqnr) are located on the chromosome and may be the evolutionary origin of qnr genes that have mobilized to unrelated species via plasmids or other mobile genetic elements.

Considerable diversity has been found amongst the Smqnr genes studied to date encoding a number of SmQnr proteins with varying capacity to reduce susceptibility to quinolones. A database of Smqnr alleles, GenBank accession numbers and amino acid substitutions in SmQnr proteins is maintained at this website with novel variants assigned numbers as they are identified.

Researchers are encouraged to submit new sequence data by email to

d.w.wareham@qmul.ac.uk

Nicola.gordon@bartsandthelondon.nhs.uk

ksimizu@juntendo.ac.jp

Nucleotide Accession Numbers of Smqnr alleles

Allele	GenBank Accession No.	Reference
Smqnr1	AB430839	Shimizu 2009
Smqnr2	AB430840	Shimizu 2009
Smqnr3	AB430841	Shimizu 2009
Smqnr4	AB430842	Shimizu 2009
Smqnr5	AB430843	Shimizu 2009
Smqnr6	AB430849	Shimizu 2009
Smqnr7	AB430845	Shimizu 2009
Smqnr8	AB430850	Shimizu 2009
Smqnr9	AB430846	Shimizu 2009
Smqnr10	AB430847	Shimizu 2009
Smqnr11	AB430848	Shimizu 2009
Smqnr12	FJ596752	Gordon 2010
Smqnr13	FJ596753	Gordon 2010
Smqnr14	FJ596754	Gordon 2010
Smqnr15	FJ596755	Gordon 2010
Smqnr16	FJ596756	Gordon 2010
Smqnr17	FJ596757	Gordon 2010
Smqnr18	FJ596758	Gordon 2010
Smqnr19	EU681371	Sanchez 2008
Smqnr20	EU681372	Sanchez 2008
Smqnr21	EU681373	Sanchez 2008
Smqnr22	EU681375	Sanchez 2008
Smqnr23	EU681381	Sanchez 2008
Smqnr24	EU681382	Sanchez 2008
Smqnr25	EU681384	Sanchez 2008
Smqnr26	EU681385	Sanchez 2008
Smqnr27	EU681388	Sanchez 2008
Smqnr28	GU565155	Wareham 2010
Smqnr29	HM190157	Wareham 2010

Amino Acid Substitutions in SmQnr1 – SmQnr29

AMINO ACID SUBSTITIONS AT POSITION RELATIVE TO SmQnr1

Allele

4

7

9

11

12

16

17

19

22

24

27

31

32

37

38

42

54

55

57

70

73

82

84

85

92

101

103

110

112

115

125

130

135

169

172

178

180

183

185

193

203

SmQnr1

P

T

V

R

R

G

A

Q

G

K

D

H

E

G

A

G

D

T

A

S

S

S

I

K

S

F

N

I

T

W

N

N

T

I

N

D

D

R

E

S

V

SmQnr2

T

K

A

E

N

H

N

SmQnr3

L

K

D

A

S

S

N

N

D

SmQnr4

L

K

A

S

S

N

S

N

D

SmQnr5

L

H

K

A

S

G

N

N

SmQnr6

L

K

V

S

N

V

N

SmQnr7

L

K

S

N

K

N

SmQnr8

L

K

S

N

N

SmQnr9

L

K

S

N

A

N

SmQnr10

L

K

S

S

N

A

N

SmQnr11

L

K

S

N

V

N

SmQnr12

L

K

A

S

S

N

N

D

SmQnr13

L

H

K

V

S

T

N

V

G

P

G

V

H

L

SmQnr14

L

K

P

R

T

A

S

S

N

N

D

SmQnr15

T

K

S

V

A

S

S

N

V

P

G

S

H

SmQnr16

T

K

S

V

A

S

S

N

V

P

G

S

G

H

SmQnr17

L

K

S

S

N

N

SmQnr18

L

K

V

S

N

V

N

SmQnr19

L

E

D

K

S

N

N

N

R

SmQnr20

L

E

K

S

N

N

N

R

SmQnr21

L

K

A

S

N

R

S

G

N

SmQnr22

L

K

S

S

N

S

A

N

SmQnr23

L

A

S

N

N

SmQnr24

L

A

K

A

S

S

N

N

D

SmQnr25

L

K

Y

Q

S

G

N

N

SmQnr26

L

K

V

A

E

N

S

N

N

SmQnr27

L

K

Y

A

E

N

N

N

SmQnr28

L

H

K

D

S

S

N

M

P

G

H

SmQnr29

L

K

Q

S

G

N

N

References

Sánchez, M., A. Hernández, J. M. Rodríguez-Martínez, L. Martínez-Martínez, and J. L. Martínez. 2008. Predictive analysis of transmissible quinolone resistance indicates Stenotrophomonas maltophilia as a potential source of a novel family of Qnr determinants. BMC Microbiol. 8:148.

Shimizu, K., K. Kikuchi, T. Sasaki, N. Takahashi, M. Ohtsuka, Y. Ono, and K. Hiramatsu. 2008. Smqnr, a new chromosome-carried quinolone resistance gene in Stenotrophomonas maltophilia. Antimicrob. Agents Chemother. 52: 3823-3825.

Gordon, N. C., and D. W. Wareham. 2010. Novel variants of the Smqnr family of quinolone resistance genes in clinical isolates of Stenotrophomonas maltophilia. J. Antimicrob. Chemother. 65:483-489

Wareham, D. W., Gordon N. C., Shimizu, K. 2010 Two new variants and creation of a repository for Stenotrophomonas maltophilia quinolone protection protein (Smqnr) genes. Ann Agent Chemother, Submitted