參考文獻 - Stenotrophomonas maltophilia 誘發L1及L2乙內醯胺酶基因表現之探討; Induction studies of L1 and L2 β-lacta

Ambler RP. 1980. The structure of β-lactamases. Philos Trans R Soc Lond B Biol Sci.

289:321-331.

Alonso A, Sanchez P, Martinez JL. 2000. Stenotrophomonas maltophilia D457R contains a cluster of genes form gram-positive bacteria involved in antibiotic and heavy metal resistance.

Antimicrob Agents Chemother. 44:1778-1782.

Arpi M, Victor MA, Mortensen I, Gottschau A, Bruun B. 1996 . In vitro susceptibility of 124 Xanthomonas maltophilia (Stenotrophomonas maltophilia) isolates: comparison of the agar dilution method with the E-test and two agar diffusion methods. APMIS. 104(2):108-14.

Avison MB, Higgins CS, von Heldreich CJ, Bennett PM, Walsh TR . 2001. Plasmid Location and Molecular Heterogeneity of the L1 and L2 beta-Lactamase Genes of Stenotrophomonas maltophilia. Antimicrob Agents Chemother.45:413-419

Bae EA, Han MJ, Kim DH. 1999. In vitro anti-Helicobacter pylori activity of some flavonoids and their metabolites. Planta Med. 65:442-443

Bebrone C, Moali C, Mahy F, Rival S, Docquier JD, Rossolini GM, Fastrez J, Pratt RF, Frere JM, Galleni M. 2001. CENTA as a Chromogenic Substrate for Studying β-Lactamases . Antimicrob Agents Chemother. 45: 1868–1871

Borradaile NM, Carroll KK, Kurowaska EM. 1999. Regulation of HepG2 cell apolipoprotein B metabolism by the citrus flavanones hesperetin and naringenin. Lipids. 34:591-598

Birnboim HC, Doly J. 1979. A rapid alkaline extraction procedure for screening recombinant plasmid DNA. Nucleic Acids Res. 7(6):1513-1523

Bush K, Sykes RB. 1986. Methodology for the study of β-lactamases. Antimicrob Agents Chemother. 30：6-10.

Bush K. 1988. β-Lactamase Inhibitors from Laboratory to Clinic. Clin Microbiol Rev. 1:

109-123

Bush K, Jacoby GA, Medeiros AA. 1995. A functional classification scheme for β-lactamases and its correlation with molecular structure. Antimicrob Agents Chemother. 39:1211–1233.

Carlsson F, Sandin C, Lindahl G.2005. Human fibrinogen bound to Streptococcus pyogenes M protein inhibits complement deposition via the classical pathway.Mol Microbiol. 56: 28-39

Clark NM, Patterson J, Lynch JP. 2003. Antimicrobial resistance among Gram-negative organisms in the intensive care unit. Curr Opin Crit Care. 9:413-423.

Crowder MW, Walsh TR, Banovic L, Pettit M, Spencer J.1998. Overexpression, Purification, and Characterization of the Cloned Metallo-β-Lactamase L1 fromStenotrophomonas maltophilia.

Antimicrob Agents Chemother. 42: 921-926

Denton M, and Kerr KG. 1998. Microbiological and Clinical Aspects of Infection Associated with Stenotrophomonas maltophilia .Clin Microbiol Rev. 11(1):57-80

García-Rodríguez JA, García Sánchez JE, García García MI, García Sánchez E, Muñoz Bellido JL.1991. Antibiotic susceptibility profile of Xanthomonas maltophilia. In vitro activity of beta-lactam/beta-lactamase inhibitor combinations. Diagn Microbiol Infect Dis. 14(3):239-43

Gould VC, and Avison MB. 2006. SmeDEF-mediated antimicrobial drug resistance in Stenotrophomonas maltophilia clinical isolates having defined phylogenetic relationships. J Antimicrob Chemother. 57：1070–1076

Hoang TT, Karkhoff-Schweizer RR, Kutchma AJ, Schweizer HP. 1998. A broad-host-range Flp-FRT recombination system for site-specific excision of chromosomally-located DNA sequences: application for isolation of unmarked Pseudomonas aeruginosa mutants. Gene.

212:77-86.

Hugh R, and Ryschenkow E. 1961. Pseudomonas maltophilia, an Alcaligenes-like species. J Gen Microbiol. 26:123-132.

Izard JW, and Kendall DA. 1994. Signal peptides: exquisitely designed transport promoters.

Mol Microbiol. 13(5):765-773

Johansson BP, Levander F, von Pawel-Rammingen U, Berggård T, Björck L, James P. 2005.

The Protein Expression of Streptococcus pyogenes Is Significantly Influenced by Human Plasma . J Proteome Res. 4: 2302- 2311

Juhnke ME, and des Jardin E. 1989. Selective Medium for Isolation of Xanthomonas maltophilia from Soil and Rhizosphere Environments. Appl Environ. Microbiol. 55: 747-750 Kobayashi Y, Sugaya Y, Tokue A. 1998. Clinical effects of β-sitosterol (phytosterol) on benign prostatic hyperplasia: preliminary study. Hinyokika Kiyo. 44:865-868.

Krueger TS, Clark EA, Nix DE. 2001. In vitro susceptibility of Stenotrophomonas maltophilia to various antimicrobial combinations. Diagn Microbiol Infect Dis. 41:71-78.

Lai CH, Chi CY, Chen HP, et al. 2004.Clinical characteristics and prognostic factors of patients with Stenotrophomonas maltophilia bacteremia.J Microbiol Immunol Infect. 37(6): 350-358.

Lambert T, Ploy MC, Denis F, Courvalin P. 1999. Characterization of the chromosomal acc(6)-Iz gene of Stenotrophomonas maltophilia. Antimicrob Agents Chemother.

43:2366-2371.

Lee S-H, Jeong T-S, Park YB.1999. Hypocholesterolemic effect of hesperetin mediated by inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase and acyl coenzyme A:

cholesterol acyltransferase in rats fed high-cholesterol diet. NutrRes. 19:1245-1258.

Lecso-Bornet M, and Bergogne-Bérézin E. 1997. Susceptibility of 100 strains of Stenotrophomonas maltophilia to three β-lactams and five β-lactam–β-lactamase inhibitor combinations. J Antimicrob Chemother. 40:717-720

Livermore DM. 1995. Bacterial resistance to carbapenems.Adv Exp Med Biol. 390:25-47

Li XZ, Zhang L, Poole K. 2002. SmeC, an outer membrance multidrug efflux protein of Stenotrophomonas maltophilia. Antimicrob Agents Chemother. 46:333-343

Lister PD, Gardner VM, Sanders CC. 1999. Clavulanate Induces Expression of the Pseudomonas aeruginosa AmpC Cephalosporinase at Physiologically Relevant Concentrations and Antagonizes the Antibacterial Activity of Ticarcillin . Antimicrob Agents Chemother. 43:

882–889

Micozzi A, Venditti M, Monaco M, Friedrich A, Taglietti F, Santilli S, Martino P. 2000.

Bacteremia due to Stenotrophomonas maltophilia in patients with hematologic malignanacies.

Clin Infect Dis. 31:705-711

Muñoz Bellido JL, Muñoz Criado S, García García I, Alonso Manzanares MA, Gutiérrez Zufiaurre MN, García-Rodríguez JA.1997. In Vitro Activities of β-Lactam–β-Lactamase Inhibitor Combinations against Stenotrophomonas maltophilia: Correlation between Methods for Testing Inhibitory Activity, Time-Kill Curves, and Bactericidal Activity. Antimicrob Agents Chemother. 41: 2612-2615

Normén L, Dutta P, Lia A, Andersson H . 2000. Soy sterol esters and β-sitostanol ester as inhibitors of cholesterol absorption in human small bowel. Am J Clin Nutr. 71:908-913.

Palleroni NJ, and Bradbury JF. 1993. Stenotrophomonas, a new bacterial genus for Xanthomonas maltophilia (Hugh 1980) Swings et al. 1983. Int. Int J Syst Bacteriol.

43:606–609.

Pankuch GA, Jacobs MR, Rittenhouse SF, Appelbaum PC. 1994.Susceptibilities of 123 Xanthomonas maltophilia Strains to Clinafloxacin, PD 131628, PD 138312, PD 140248,Ciprofloxacin, and Ofloxacin. Antimicrob. Agents Chemother. 38:369-370

Paton R, Miles RS, Amyes SG. 1994. Biochemical Properties of Inducible β-Lactamases Produced from Xanthomonas maltophilia . Antimicrob Agents Chemother. 38: 2143-2149

Richmond MH, Sykes RB . 1973. The β-lactamases of gram-negative bacteria and their possible physiological role. Adv Microb Physiol. 9:31-88.

Rosta S, Mett H.1989. Physiological Studies of the Regulation of β-Lactamase Expression in Pseudomonas maltophilia . Journal of Bacteriology. 171: 483-487

Saino Y, Inoue M, Mitsuhashi S. 1984. Purification and properties of an inducible cephalosporinase from Pseudomonas maltophilia GN12873. Antimicrob Agents Chemother.

25:362–365.

Saino Y, Kobayashi F, Inoue M, Mitsuhashi S. 1982. Purification and Properties of Inducible Penicillin ,β-LactamaseIsolated from Pseudomonas maltophilia. Antimicrob Agents Chemother.

22:564-570

Sánchez P, Alonso A, Martinez JL. 2002. Cloning and characterization of SmeT, a repressor of the Stenotrophomonas maltophilia Multidrug efflux pump SmeDFF. Antimicrob Agents Chemother. 46:3386-3393.

Schweizer HP, and Hoang TT.1995. An improved system for gene replacement and xylE fusion analysis in Pseudomonas aeruginosa. Gene. 158: 15-22

Simon R, Priefer U, Pühler A. 1983. A broad host range mobilization system for in vivo genetic engineering: transposon mutagenesis in Gram-negative bacteria. Bio/Technology. 1:784-791.

Stephen J. Cavalieri, Christine C. Sanders, and Charles new.1991. Influence of β-Lactamase Inhibitors on the Potency of Their Companion Drug with Organisms Possessing Class I Enzymes. Antimicrob Agents Chemother. 35:1343-1347

Smit WJ, Boquest AL, Geddes JE, Tosolini FA.1994. The antibiotic susceptibilities of Xanthomonas maltophilia and their relation to clinical management. Pathology. 26(3):321-4

Sutter VL. 1968. Identification of Pseudomonas species isolated from hospital environment and human sources. Appl Microbiol. 16:1532–1538.

Then RL. 1987. Ability of newer β-lactams to induce β-lactamase production in Enterobacter cloacae. Eur J Clin Microbiol. 4:451-455.

Ubeda P, Salavert M, Giner S, Jarque I, Lopez-Aldeguer J, Perez-Belles C, Gobernado M.1998.

Bacteraemia from Stenotrophomonas maltophilia:clinical epidemiological study and resistance profile. Rev Esp Quimioter. 11:205–215

Valdezate S, Vindel A, Loza E, Baquera F, Canton R. 2001 Antimicrobial susceptibilities of unique Stenotrophomonas maltophilia clinical strains. Antimicrob Agents Chemother.

45:1581—1584.

Villanova PA .1990. National Committee for Clinical Laboratory Standards Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria that Grow Aerobically—Second Edition.

Approved Standard M7-A2. NCCLS.

Walsh TR, MacGowan AP, Bennett PM.1997. Sequence analysis and enzyme kinetics of the L2 serine β-lactamase from Stenotrophomonas maltophilia. Antimicrob Agents Chemother. 41:

1460–1464.

Wang WS, Liu CP, Lee CM, Huang FY. 2004. Stenotrophomonas maltophilia bacteremia in adults: four years' experience in a medical center in northern Taiwan. J Microbiol Immunol Infect. 37(6):359-65

Wilt TJ, MacDonald R, Ishani A.1999. β-sitosterol for the treatment of benign prostatic hyperplasia: a systematic review. BJU Int.83:976-983.

Windhorst S, Frank E, Georgieva DN, Genov N, Buck F, Borowski P, Weber W. 2002. The major extracellular protease of the nosocomial pathogen Stenotrophomonas maltophilia: characterization of the protein and molecular cloning of thegene. J Biol Chem.

277:11042-11049.

Zhang L, Li XZ, Poole K. 2001. SmeDEF multidrug efflux pump contributes to intrinsic multidrug resistance in Stenotrophomonas maltophilia .Antimicrob Agents Chemother.

45:3497-3503.

圖

g. 1. Physical map of inserted xylE-Tc cassette of plasmid pOKXT

Fi HindIII

Fig. 2. Construction of plasmid pEXNL1XT.

Fig. 3. Construction of plasmid pEXNL2XT.

A

0.1 1 10

0 1 2 3 4 5 6 7 8 9

Time(hr)

logO D

450

nm

NL1-

NL2-B

0.1 1

0 1 2 3 4 5

Time(hr)

logO D 450n m

NL1-

NL2-Fig. 4.Growth curves of the strains NL1^- and NL2^- in LB medium with clavulanic acid of 50 μg/ml. Overnight culture (A) and four hours culture(B) of the strains NL1^- and NL2^-.

Fig. 5. Induction kinetics of strains NL1^- and NL2^- by clavulanic acid of 50 μg/ml

0 50 100 150 200 250 300 350

0 2 4 6 8 10 12 14 16 18

Time(min)

C230 specific activit

NL1-y 450(units/OD)

A

Fig. 6. Growth curves of the strain NL1^- in LB medium and LB medium containing cefuroxime ( 50 μg/ml) ， hesperetin ( 500 μg/ml) and hesperetin/cefuroxime ( 500 μg/ml/ 50 μg/ml), respectively. Overnight culture (A) and four hours culture(B) of the strain NL1^- .

B

A

Fig. 7. Growth curves of the strain NL2^- in LB medium and LB medium containing cefuroxime (50 μg/ml) ， hesperetin (500 μg/ml) and hesperetin/cefuroxime (500 μg/ml/50 μg/ml), respectively.Overnight culture (A) and four hours culture(B) of the strain NL2^-.

B

0 50 100 150 200 250 300

0 2 4 6 8 10 12 14 16 18 20 22

Time(min)

C230 specific activit

NL1-+HES NL1-+CFU

y (units/ OD450) NL1-+HES/CFU

Fig. 8. Induction kinetics of strain NL1^- in LB medium and LB medium containing cefuroxime(50 μg/ml), hesperetin (500 μg/ml), and hesperetin /cefuroxime (500 μg/ml/50 μg/ml), respectively.

0 50 100 150 200 250 300 350 400 450 500

0 2 4 6 8 10 12 14 16 18 20 22

Time(min)

C230 specific activit

NL2-+HES

NL2-+CFU

y NL2-CFU/HES

(units/OD450)

Fig. 9. Induction kinetics of strain NL2^- in LB medium and LB medium containing cefuroxime (50 μg/ml) ， hesperetin (500 μg/ml) and hesperetin/cefuroxime (500 μg/ml/50 μg/ml), respectively.

Fig. 10. The chemical structure of hesperetin

Fig. 11. The chemical structure of β-sitosterol

0 Induction concentration (μg/ml)

C 23 0 sp ecific activ it

^NL1^- NL2

-y (U /O D

450

)

Fig. 12. Induction of C23O activity of strains NL1^-and NL2^- grown in LB medium containing clavulanic acid (2、8、10、16、50 μg/ml) and cefuroxime (50 μg/ml), respectively.

表

TABLE 1. The optimal density at 450 nm and the induced C23O activity of strains NL1^- and NL2^- grown in LB medium containing different additives.

NL1^- NL2 -Medium OD₄₅₀ C23O activity

(U^c/OD450) OD₄₅₀ C23O activity

acfu: cefuroxime at concentration of 50 μg/ml;

bND: Non-Detectable

^cU: One unit of enzyme activity was designated as the amount of enzyme that hydrolyzes 1 nmol of catechol per min at 25 °C, pH7.5.

TABLE 2. The optimal density at 450 nm and the induced C23O activity of strains NL1^- and NL2^- grown in LB medium containing clavulanate of different concentrations.

OD₄₅₀

aU：One unit of enzyme activity was designated as the amount of enzyme that hydrolyzes 1 nmol of catechol per min at 25 °C, pH7.5.

TABLE 3. The optimal density at 450 nm and the induced C23O activity of strains NL1^- and NL2^- grown in XOLN medium containing 1% different carbon sources.

OD₄₅₀ C23O activity (U^a/OD₄₅₀) Carbon source

(1%) NL1^- NL2^- NL1^- NL2 Sucrose 0.52 0.5424 106 173

Glucose 0.6495 0.6887 119 178

Maltose 0.7501 0.7553 126 188

Lactose 0.482 0.4799 123 178

Glycerol 0.3658 0.38 101 176

aU：One unit of enzyme activity was designated as the amount of enzyme that hydrolyzes 1 nmol of catechol per min at 25 °C, pH7.5.

TABLE 4. The optimal density at 450 nm and the induced C23O activity of strains NL1^- and NL2^- grown in LB medium containing different additives.

OD₄₅₀ C23O activity (U^d/OD₄₅₀) Medium NL1^- NL2^- NL1^- NL2

-LB 1.275 1.257 ND^b ND

LB+β-S^C 1.335 1.282 ND ND

LB+cfu^a 1.358 1.278 195 265

LB+cfu^a/β-S^C 1.326 1.183 185 260

acfu: cefuroxime at concentration of 50 μg/ml.

b ND: Non-Detectable.

Cβ-S:β-sitosterol at concentration of 10 mg/ml.

dU：One unit of enzyme activity was designated as the amount of enzyme that hydrolyzes 1 nmol of catechol per min at 25 °C, pH7.5.

TABLE 5. Susceptibility test of strains N, NL1^-, and NL2^-. MIC^a (μg/ml)

Antimicrobial N NL1-

NL2-clavulanate 128 128 128

Ticarcillin >256 >256 32

Tic/ CA(2/1)^b 16/8 4/2 32/16

pp >256 >256 >256

PP/ CA(2/1)^b 128/64 32/16 128/64

aMICs were measured by agar dilution method recommended by the National Committee for Clinical Laboratory Standards.

b2/1 β-lactams : inhibitor ration of 2:1

c2 μg/ml clavulanate concentration were fixed of 2 μg/ml

Abbreviations: Cab: carbenicllin; CA: clavulanate; Amo; amoxicillin; Azt; aztreonam ; Tic:Ticarcillin; pp:piperacillin

TABLE 6.The optimal density at 450 nm and the induced C23O activity of strains NL1^- and NL2^- grown in LB medium containing different additives.

Clavulanate(16) 1.2122 99 1.0656 76 Aztreonam (32) 1.2026 ND^b 0.6935 295 Azt/CA((32/16) 1.0072 192 0.4919 391 Clavulanate(4) 1.15 ND^b 1.1464 ND^b

Carbenicllin (8) 1.2044 55 0.957 158 Cab/CA(8/4) 0.5384 201 1.0566 220 Amoxicillin (8) 1.0226 83 1.0916 118

Amo/CA(8/4) 0.2251 152 1.19 134 Clavulanate(4) 1.1684 ND^b 1.0514 ND^b

Aztreonam (8) 1.0818 ND^b 1.0304 215 Azt/CA(8/4) 1.115 134 1.052 297

aU：One unit of enzyme activity was designated as the amount of enzyme that hydrolyzes 1 nmol of catechol per min at 25 °C, pH7.5.

b ND: Non-Detectable.

Abbreviations: Cab: carbenicllin; CA: clavulanate; Amo; amoxicillin; Azt; aztreonam ; Tic:Ticarcillin; pp:piperacillin

TABLE 7. Susceptibility test and the induced C23O activity of strains N, NL1^-and NL2^-.

MIC^c(μg/ml) C23O activity(U^a/OD₄₅₀) AZT CA AZT/CA AZT32 CA16 AZT32/CA16 N >256 128 32/16

NL1^- >256 128 32/16 ND^b 99 192 NL2^- 16 128 16/8 159 76 391

aU：One unit of enzyme activity was designated as the amount of enzyme that hydrolyzes 1 nmol of catechol per min at 25 °C, pH7.5.

^bND: Non-Detectable.

c MICs were measured by agar dilution method recommended by the National Committee for Clinical Laboratory Standards.

Abbreviations: CA: clavulanate; Azt; aztreonam

TABLE 8. Susceptibility test and the induced C23O activity of strains N, NL1^- and NL2^-.

aU: One unit of enzyme activity was designated as the amount of enzyme that hydrolyzes 1 nmol of catechol per min at 25 °C, pH7.5.

MIC^c(μg/ml) C23O activity(U^a/OD₄₅₀) Cab CA Cab/CA Cab8 CA4 Cab8/CA4

N >256 128 64/32

NL1^- >256 128 8/4 55 ND^b 201 NL2^- 128 128 32/16 158 ND 220

^bND: Non-Detectable.

c MICs were measured by agar dilution method recommended by the National Committee for Clinical Laboratory Standards.

Abbreviations: CA: clavulanate; Cab: carbenicllin;

TABLE 9. Susceptibility test and the induced C23O activity of strains N, NL1^- and NL2^-.

MIC^c(μg/ml) C23O activity (U^a/OD₄₅₀) Amo CA Amo/CA Amo8 CA4 Amo8/CA4 N >256 128 128/64

NL1^- >256 128 8/4 83 ND^b 152 NL2^- >256 128 128/64 118 ND 134

aU：One unit of enzyme activity was designated as the amount of enzyme that hydrolyzes 1 nmol of catechol per min at 25 °C, pH7.5.

^bND: Non-Detectable.

^c MICs were measured by agar dilution method recommended by the National Committee for Clinical Laboratory Standards.

Abbreviations: CA: clavulanate;Amo; amoxicillin

附錄一、 Classification schemes for bacterial β-lactamase

substrates^a CA^b EDTA

Representative enzymes

TEM-3…. TEM-105, SHV-2…. SHV-39

2br A

Pen +/- -

TEM-30….. TEM-39…(IRT 1-IRT-26), SHV-10

2c A Pen, carbencillin + - PSE-1, PSE-3, PSE-4

2d D Pen, cloxacillin +/- - OXA-1…OXA-40, OXA-10=PSE-2 2e A

Ceph + -

Inducible cephalosporinase from Pr.vulgaris, SFO-1, L2

2f A Ceph, pen,

carbapenems + -

NMC-A, SME-1, IMI-1

3 B Carbapenems,

Often, all ceph, pen, No monobactam

- +

L1 from S, maltophilia, CfiA/CcrA from B. gragilis, VIM-1, IMP-1…. IMP-9

4 Not determined

Pen - - Penicillinase from B. cepacia

a Ceph：cephalosporine；Pen：penicillin bCA：clavulanic acid

Source：(Bush, Jacoby and Medeiros，1995)

附錄二、本實驗所使用菌株

Strain Characteristics Source or reference

E. coli

S17-1 thi pro recA hsdR^-，RP4:2Tc:Mu:Km T7，λpir

Simon et al., 1983

S. maltophilia

N Clinical isolate was obtained in China Medical University Hospital.

Our laboratory, Yang

NL1^- N L1 mutant constructed by inserting a xylE-Tc cassette into the SacI restriction site of the L1 gene

Our laboratory, Yang

NL2^- N L2 mutant constructed by inserting a xylE-Tc cassette into the StuI restriction site of the L2 gene

Our laboratory, Yang

附錄三、本實驗所使用質體

Plasmids Characteristics Source or reference

pEX18Tc 6,349bp, pMB1 replicon, oriT, lacZα,SacB,Tc^r

Hoang et al.,1998

pOK12 2,134 bp, P15A replicon, lacZα,Km^r Messing ＆ Vieira, 1991

pX1918GT 5,154 bp, lacZα, Gm^r, AP^r xylE

Schweizer et al., 1995

pTTc A 1.4-kb PCR amplicon containing tetracycline resistance (Tc^r) gene was cloned into a T-vector; Ap^r

This study

pTXylERI B1.3-kb PCR amplicon containing xylE gene was cloned into a T-vector; Ap^r

Yang laboratory

pTXylETc An BamHI-XbaI DNA fragment ( 1.4-kb) from plasmid (A) was cloned into the BamHI-XbaI site of (B); Tc^r, AP^r

This study

pOKXylETcRI An EcoRI DNA fragment ( 2.7-kb) from plasmid pTXylETc was cloned into the EcoRI site of pOK12; Tc^r, Km^r

This study

pXXT An EcoRI DNA fragment ( 2.7-kb) from plasmid pOKXylETcRI was cloned into the EcoRI site of pX1918GT; Tc^r, Ap^r

This study

pOKXTHindIII An HindIII DNA fragment ( 2.7-kb) from plasmid pXXT was cloned into the HindIII site of pOK12; Tc^r, Km^r

This study

pEXNL1XT Derivatives of pEX18Tc, containing the L1 gene inserted an xylE-Tc cassette.

Yang Laboratory

pEXNL2XT Derivatives of pEX18Tc, containing the L2 gene inserted an xylE-Tc cassette.

Yang Laboratory

附錄四、

S. maltophilia produces at least two chromosomally mediated β-lactamases, L1 and L2

molecular mass of 63 kDa, STXK active-site motif, SDN loop motif

Sequence analysis

873 bp

(GC content: 68.4%)

909 bp

(GC content : 71.6%) Substrate penicillins ; cephalosporins;

carbapenem

penicillins ; cephalosporins;

monobactams

Inhibitor EDTA clavulanic acid

^a This enzyme from S. maltophilia ULA-511

b This enzyme from S. maltophilia 1275 IID

附錄五、

Susceptibility of S. maltophilia to β-lactams/β-lactamase inhibitor combinations

a2/1 β-lactams : inhibitor ration of 2:1

b2 μg/ml clavulanate concentration were fixed of 2 μg/ml

Abbreviations: Cab: carbenicllin; CA: clavulanate; Amo; amoxicillin; Azt; aztreonam ; Tic:Ticarcillin

在文檔中 Stenotrophomonas maltophilia 誘發L1及L2乙內醯胺酶基因表現之探討; Induction studies of L1 and L2 β-lactamases in Stenotrophomonas maltophilia (頁 69-100)