Small Molecule Inhibitors of a Glycoside Hydrolase Attenuate Inducible AmpC-mediated β-Lactam Resistance

The increasing spread of plasmid-borne ampC-ampR operons is of considerable medical importance, since the AmpC β-lactamases they encode confer high level resistance to many third generation cephalosporins. Induction of AmpC β-lactamase from endogenous or plasmid-borne ampC-ampR operons is mediated by a catabolic inducer molecule, 1,6-anhydro-N-acetylmuramic acid (MurNAc) tripeptide, an intermediate of the cell wall recycling pathway derived from the peptidoglycan. Here we describe a strategy for attenuating the antibiotic resistance associated with the ampC-ampR operon by blocking the formation of the inducer molecule using small molecule inhibitors of NagZ, the glycoside hydrolase catalyzing the formation of this inducer molecule. The structure of the NagZ-inhibitor complex provides insight into the molecular basis for inhibition and enables the development of inhibitors with 100-fold selectivity for NagZ over functionally related human enzymes. These PUGNAc-derived inhibitors reduce the minimal inhibitory concentration (MIC) values for several clinically relevant cephalosporins in both wild-type and AmpC-hyperproducing strains lacking functional AmpD. The increasing spread of plasmid-borne ampC-ampR operons is of considerable medical importance, since the AmpC β-lactamases they encode confer high level resistance to many third generation cephalosporins. Induction of AmpC β-lactamase from endogenous or plasmid-borne ampC-ampR operons is mediated by a catabolic inducer molecule, 1,6-anhydro-N-acetylmuramic acid (MurNAc) tripeptide, an intermediate of the cell wall recycling pathway derived from the peptidoglycan. Here we describe a strategy for attenuating the antibiotic resistance associated with the ampC-ampR operon by blocking the formation of the inducer molecule using small molecule inhibitors of NagZ, the glycoside hydrolase catalyzing the formation of this inducer molecule. The structure of the NagZ-inhibitor complex provides insight into the molecular basis for inhibition and enables the development of inhibitors with 100-fold selectivity for NagZ over functionally related human enzymes. These PUGNAc-derived inhibitors reduce the minimal inhibitory concentration (MIC) values for several clinically relevant cephalosporins in both wild-type and AmpC-hyperproducing strains lacking functional AmpD. The expression of inducible chromosomal AmpC β-lactamases (1Normark S. Ghuysen-M. J Hakenbeck R. Bacterial Cell Wall: New Comprehensive Biochemistry. 27. 1994: 485-503Google Scholar, 2Jacobs C. Huang L.J. Bartowsky E. Normark S. Park J.T. EMBO J. 1994; 13: 4684-4694Crossref PubMed Scopus (300) Google Scholar) is one increasingly problematic resistance mechanism seen in many Gram-negative bacteria, including clinically opportunistic pathogens, such as Pseudomonas aeruginosa and Citrobacter freundii. These AmpC β-lactamases inactivate a broad range of β-lactam antibiotics, thereby conferring resistance to clinically important cephamycins, cephalosporins, and even monobactams, next generation β-lactams designed to be stable against β-lactamases (3Jacoby G.A. Munoz-Price L.S. N. Engl. J. Med. 2005; 352: 380-391Crossref PubMed Scopus (667) Google Scholar). One alarming development resulting from continued β-lactam use is the spread of genetically diverse, plasmid-borne ampC, including those that are under inducible control. Indeed, the movement of ampC genes onto plasmids (4Bradford P.A. Urban C. Mariano N. Projan S.J. Rahal J.J. Bush K. Antimicrob. Agents Chemother. 1997; 41: 563-569Crossref PubMed Google Scholar, 5Miriagou V. Tzouvelekis L.S. Villa L. Lebessi E. Vatopoulos A.C. Carattoli A. Tzelepi E. Antimicrob. Agents Chemother. 2004; 48: 3172-3174Crossref PubMed Scopus (46) Google Scholar, 6Barnaud G. Arlet G. Verdet C. Gaillot O. Lagrange P.H. Philippon A. Antimicrob. Agents Chemother. 1998; 42: 2352-2358Crossref PubMed Google Scholar, 7Nakano R. Okamoto R. Nakano Y. Kaneko K. Okitsu N. Hosaka Y. Inoue M. Antimicrob. Agents Chemother. 2004; 48: 1151-1158Crossref PubMed Scopus (56) Google Scholar, 8Fortineau N. Poirel L. Nordmann P. J. Antimicrob. Chemother. 2001; 47: 207-210Crossref PubMed Scopus (70) Google Scholar) as well as other transposable elements has greatly increased the prevalence of this type of resistance mechanism in Gram-negative organisms (9Woodford N. Reddy S. Fagan E.J. Hill R.L. Hopkins K.L. Kaufmann M.E. Kistler J. Palepou M.F. Pike R. Ward M.E. Cheesbrough J. Livermore D.M. J. Antimicrob. Chemother. 2006; 59: 102-105Crossref PubMed Scopus (76) Google Scholar). The regulation of ampC gene expression can vary between genera of Gram-negative bacteria. In some, chromosomal ampC is expressed constitutively, although high level expression has been suggested to decrease bacterial fitness and virulence, at least in Salmonella enterica (10Folkesson A. Eriksson S. Andersson M. Park J.T. Normark S. Cell. Microbiol. 2005; 7: 147-155Crossref PubMed Scopus (36) Google Scholar). Often, however, chromosomal ampC β-lactamase is inducible as found in various clinically relevant opportunistic pathogens, such as Enterobacter spp., and P. aeruginosa (11Hanson N.D. Sanders C.C. Curr. Pharm. Des. 1999; 5: 881-894PubMed Google Scholar, 12Poirel L. Guibert M. Girlich D. Naas T. Nordmann P. Antimicrob. Agents Chemother. 1999; 43: 769-776Crossref PubMed Google Scholar). A major achievement in the field of antibiotic research has been the discovery of β-lactamase inhibitors. These inhibitors have been shown, in some cases, to reverse antibiotic resistance mediated by certain classes of β-lactamase. There are currently three main β-lactamase inhibitors available on the market, each having the same β-lactam core found in β-lactam antibiotics. One of these inhibitors, clavulanic acid, however has been found to be of limited use against AmpC (13Livermore D.M. Clin. Microbiol. Rev. 1995; 8: 557-584Crossref PubMed Google Scholar, 14Li C. Nicolau D.P. Lister P.D. Quintiliani R. Nightingale C.H. J. Antimicrob. Chemother. 2004; 53: 297-304Crossref PubMed Scopus (16) Google Scholar). The other two, sulbactam and tazobactam, demonstrate effectiveness against certain bacteria, but their general utility against AmpC remains unclear (13Livermore D.M. Clin. Microbiol. Rev. 1995; 8: 557-584Crossref PubMed Google Scholar, 15Kadima T.A. Weiner J.H. Antimicrob. Agents Chemother. 1997; 41: 2177-2183Crossref PubMed Google Scholar, 16Doi Y. Wachino J. Ishiguro M. Kurokawa H. Yamane K. Shibata N. Shibayama K. Yokoyama K. Kato H. Yagi T. Arakawa Y. Antimicrob. Agents Chemother. 2004; 48: 2652-2658Crossref PubMed Scopus (44) Google Scholar, 17Thomson K.S. Sanders C.C. Moland E.S. Antimicrob. Agents Chemother. 1999; 43: 1393-1400Crossref PubMed Google Scholar, 18Bush K. Macalintal C. Rasmussen B.A. Lee V.J. Yang Y. Antimicrob. Agents Chemother. 1993; 37: 851-858Crossref PubMed Scopus (237) Google Scholar, 19Nakae T. Saito K. Nakajima A. Microbiol. Immunol. 2000; 44: 997-1001Crossref PubMed Scopus (9) Google Scholar). Accordingly, the development of new strategies to cope with the growing problem of AmpC β-lactamases are of considerable interest and importance. The mechanism by which inducible AmpC β-lactamase expression is controlled is directly related to the integrity of the murein cell wall. This regulatory mechanism elegantly links antibiotic resistance to the dynamic and continuously changing balance between peptidoglycan biosynthesis and degradation (Fig. 1). These two metabolic activities must be strictly controlled by bacteria to enable cell growth yet avoid autolysis (20Jacobs C. Frere J-M. Normark S. Cell. 1997; 88: 823-832Abstract Full Text Full Text PDF PubMed Scopus (273) Google Scholar). During cell division, a considerable amount of the murein sacculus is degraded by various autolysins and recycled (21Vollmer W. Holtje J.V. Curr. Opin. Microbiol. 2001; 4: 625-633Crossref PubMed Scopus (82) Google Scholar, 22Park J.T. J. Bacteriol. 1993; 175: 7-11Crossref PubMed Google Scholar). The GlcNAc-1,6-anhydro-MurNAc 2The abbreviations used are: MurNAc, N-acetylmuramic acid; BisTris, 2-[bis(2-hydroxyethyl)amino]-2-(hydroxymethyl)propane-1,3-diol; MIC, minimal inhibitory concentration. peptide degradation products liberated by these autolysins are transported into the cytosol (2Jacobs C. Huang L.J. Bartowsky E. Normark S. Park J.T. EMBO J. 1994; 13: 4684-4694Crossref PubMed Scopus (300) Google Scholar), where, upon arrival, the nonreducing GlcNAc residue is removed by a family 3 β-glucosaminidase known as NagZ. The resulting products are N-acetyl-d-glucosamine and a series of 1,6-anhydro-MurNAc tri-, tetra-, and pentapeptides (Fig. 2) (23Cheng Q. Li H. Merdek K. Park J.T. J. Bacteriol. 2000; 182: 4836-4840Crossref PubMed Scopus (136) Google Scholar, 24Votsch W. Templin M.F. J. Biol. 2000; Full Text Full Text PDF PubMed Scopus Google Scholar). These 1,6-anhydro-MurNAc catabolic the of inducible in an a of the cell wall derived from these catabolic is in of The dynamic balance between the of these catabolic and is these bacteria β-lactams and of of murein cell wall two N-acetyl-d-glucosamine and the series of 1,6-anhydro-MurNAc tri-, tetra-, and inducer that of ampC of the inhibitors the of the of by a The these two with the of ampC is L. Normark S. S. A. PubMed Scopus Google Scholar), a of the family of S. S. A. PubMed Scopus Google Scholar). ampC and are found in a operon in which is directly of The for these two genes and to this thereby of ampC E. Normark S. Microbiol. 5: PubMed Scopus Google Scholar). In the of is to to and a in the that of ampC (20Jacobs C. Frere J-M. Normark S. Cell. 1997; 88: 823-832Abstract Full Text Full Text PDF PubMed Scopus (273) Google Scholar, T. Park J.T. J. Bacteriol. PubMed Scopus Google Scholar). β-lactams are murein biosynthesis is the balance between the inducer and is (21Vollmer W. Holtje J.V. Curr. Opin. Microbiol. 2001; 4: 625-633Crossref PubMed Scopus (82) Google Scholar, D. E. Antimicrob. Agents Chemother. 2000; 44: PubMed Scopus Google Scholar), and the 1,6-anhydro-MurNAc in the One of these to be 1,6-anhydro-MurNAc tripeptide, is some as to 1,6-anhydro-MurNAc is in the The 1,6-anhydro-MurNAc and the 1,6-anhydro-MurNAc have both been to ampC (2Jacobs C. Huang L.J. Bartowsky E. Normark S. Park J.T. EMBO J. 1994; 13: 4684-4694Crossref PubMed Scopus (300) Google Scholar). is to from and thereby an that of ampC (20Jacobs C. Frere J-M. Normark S. Cell. 1997; 88: 823-832Abstract Full Text Full Text PDF PubMed Scopus (273) Google Scholar). avoid of bacteria the concentration of the inducer molecule by and recycling the of a J.V. A. Microbiol. 1994; PubMed Scopus Google Scholar, C. M. K. J. D. J. Park Normark S. Frere Microbiol. 1995; PubMed Scopus Google Scholar) that the peptide of both the GlcNAc-1,6-anhydro-MurNAc as well as the inducer 1,6-anhydro-MurNAc J.V. A. Microbiol. 1994; PubMed Scopus Google Scholar, C. M. K. J. D. J. Park Normark S. Frere Microbiol. 1995; PubMed Scopus Google Scholar). resistance to β-lactams seen in many strains of Gram-negative bacteria from in the gene C. O. C. A. Antimicrob. Agents Chemother. 2005; PubMed Scopus Google Scholar, A. N.D. J. Antimicrob. Chemother. PubMed Scopus Google Scholar, N. O. M. M. N. Antimicrob. Agents Chemother. PubMed Scopus Google Scholar, L. A. Antimicrob. Agents Chemother. 2000; 44: PubMed Scopus Google Scholar). These the concentration of 1,6-anhydro-MurNAc and to AmpC expression S. Normark S. J. Bacteriol. PubMed Scopus Google Scholar). The of NagZ in a Gram-negative over J. Bacteriol. PubMed Google Scholar), although has been that of the gene from bacteria the ampC-ampR operon their to β-lactam (23Cheng Q. Li H. Merdek K. Park J.T. J. Bacteriol. 2000; 182: 4836-4840Crossref PubMed Scopus (136) Google Scholar, 24Votsch W. Templin M.F. J. Biol. 2000; Full Text Full Text PDF PubMed Scopus Google Scholar). These a strategy to β-lactam resistance blocking formation of the inducer molecule inhibition of NagZ, of AmpC β-lactamase be with the of β-lactam antibiotics. Accordingly, inhibition of NagZ of certain Gram-negative bacterial many classes of β-lactam antibiotics. strategy be of for from by opportunistic Gram-negative as well as for certain in P. for is known to resistance to β-lactams high level of an inducible AmpC β-lactamase and using or that are and Bacterial from and from from New E. and from E. from from and from of for the C. operon by in the of the V. NagZ, by the and of bacterial strains used in the antibiotic by the of and and the E. to by using by with a acid in and under a with using and on a at for to of used in at the and for NagZ V. V. gene by the using from a V. The and reverse used to an and and in onto the The with and into a of a of using The into E. from a and by and to the and of the expression and of V. to in a at in of with of NagZ from by the of by a at with by and at The in of of for and by The by and onto a acid with and The with of by two of with and The NagZ from the using with The against BisTris, and at and for V. to using an and by using on the In growth in and BisTris, of in complex with by with at a of to for at and the to using and BisTris, as against the at the with to the growth of the of the complex and into by in and BisTris, with increasing of a concentration of The by directly into using an from of the complex at in a using and A. on Scholar, Biol. 1994; PubMed Scopus Google Scholar). and for V. NagZ in with for the complex by molecular using the Biol. 1994; PubMed Scopus Google Scholar) Biol. 2004; PubMed Scopus Google Scholar) and the structure as the to a of for against the PubMed Scopus Google Scholar). One NagZ molecule in the and to by of and using T.A. M. A. 47: PubMed Scopus Google Scholar) and Biol. 59: PubMed Scopus Google Scholar), the of and the of the NagZ A of into this using and using using P. K. Biol. 2004; PubMed Scopus Google Scholar) in and using G. C. PubMed Scopus Google Scholar). The to and the using acid of the are in of the as by J. 1993; Google Scholar). The are in in to the high cell cell range is the and is the of of and for in the and of and for in the and of of from by from the in to the high is the and is the of of and for in the and of by from the in a new of of the various is N. 2006; 4: PubMed Scopus Google Scholar). The of in J found for of NagZ from V. in at using a by the of of as by at by the of and for of NagZ that the stable in the over the of the used at a concentration of with as a at a concentration of inhibitors at from 3 to values by of from of ampC-ampR from C. from C. used as the for of ampC-ampR The using the in and in The with and into a of a of using The used directly to E. using of from a and by and to the and of the ampC-ampR of the of by of with a small amount of the of bacteria and to at to an of a range of of β-lactam by of of the concentration of antibiotic in The to by the of of in or of These with of the and to at for The at for and the from the concentration of antibiotic at which growth in bacterial by of with the and the to at the The by for 3 at The in of and of this used to the of and of and of 3 in of These for at with the bacterial with of or on the at the of the inhibition in by of with a small amount of the of bacteria, and the to at to an of of used to the or These for at using the and or the of each removed at and and by for 3 at The in of and for 3 at which the and the at the β-lactamase the in and at The cell removed by at for and the used directly in the in at using a by the of of from concentration as by at by the of and for of the by using as a NagZ and are of family 3 A. J. PubMed Scopus Google Scholar) of glycoside that on a of other and V. NagZ and using as a we on the basis of to other NagZ the the with other of family this is to use a mechanism a intermediate and C. S. Biochemistry. 2000; PubMed Scopus Google Scholar). designed to such have been and with from several other of glycoside found in that are inhibitors of NagZ are and those that are known to this J. Bacteriol. PubMed Google Scholar, E. S. J. Biol. Full Text Full Text PDF PubMed Scopus (56) Google Scholar). of the inhibitors of for several of are the and the 1999; PubMed Google Scholar). M. L. A. D.M. J. PubMed Scopus Google Scholar, D. D.M. A. Scopus Google Scholar) acid, T. H. K. T. K. M. T. J. PubMed Scopus Google Scholar), and a related M. A. 2005; 88: Scopus Google Scholar) (Fig. 2) have been to the family human J. Biol. 1994; Full Text PDF PubMed Google Scholar, A. 2006; PubMed Google Scholar) and the family human M. L. A. D.M. J. PubMed Scopus Google Scholar, T. H. K. T. K. M. T. J. PubMed Scopus Google Scholar, 1993; PubMed Google Scholar, M. A. 2005; 88: Scopus Google Scholar, K. S. S. H. J. 1995; 48: PubMed Scopus Google Scholar, K. S. 1995; Scholar, K. S. H. 1997; Scopus Google Scholar). These two human are functionally related to NagZ, since they GlcNAc from the nonreducing of but they use a mechanism and are of Biochemistry. 2005; 44: PubMed Scopus Google Scholar). is known the inhibitory of NagZ to these various inhibitors, but we however, that at least one of or be a of NagZ, since the have been to related from other of glycoside 1999; PubMed Google Scholar, M. A. 2005; 88: Scopus Google Scholar). and as inhibitors of NagZ from V. three found to be inhibitors but is although is against from family of glycoside M. A. 2005; 88: Scopus Google Scholar). These on which is a of the human family J. Biol. 1994; Full Text PDF PubMed Google Scholar, K. G.A. J. Biol. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar) and family M. L. A. D.M. J. PubMed Scopus Google Scholar, 1993; PubMed Google Scholar). This of inhibitory selectivity a in a for blocking the of NagZ, since in a inhibition of these human be however, that using as a a and NagZ be by the of inhibitors, we the structure of NagZ in complex with by and selectivity of inhibitors for and for the A. 2006; PubMed Google for the M. A. 2005; 88: Scopus Google D. J. Biol. 2005; Full Text Full Text PDF PubMed Scopus Google N. 2006; 4: PubMed Scopus Google Scholar) in a new of in with the NagZ from V. NagZ is a of E. NagZ acid is an for of inhibitors of the E. and other related NagZ enzymes. from the the of V. NagZ by J. and L. but of the structure have been in the as a for molecular we to the structure of in complex with NagZ a with the from the of the the The are by This structure has been to be many glycoside The molecular new that be to the NagZ (Fig. The 2) in an the (Fig. A of are the the is to and a with and the of the to (Fig. The of the of to to the the a molecule that in a to residue of the (Fig. the of with the and the in values as the from the the (Fig. and as a the well the 3 and the of of this to for the same as the of and in the of the of is from to a the and In we that the of a of this of acid (Fig. which with the of the movement of the the to of the the be by increasing the at and two with the that of to (Fig. at The of a NagZ in which with a The resulting that the same as the of one for the of is to the The of that the is is the by the is in the the the for and to and are on their values are and a to the in The the of to be the and that the of increasingly the for a with using The of the complex with the and complex The complex is in with the of and the and in The and are in and the and are in is and is onto the which is in using The the of this several can be from this acid residue is between the V. and E. the of this we that directly the a by a molecule (Fig. This directly with the of family D. S. J. Biol. PubMed Scopus Google Scholar), family G. L. T. 2000; 8: Full Text Full Text PDF PubMed Scopus Google Scholar) and family E.J. S.J. Biol. 2006; 13: PubMed Scopus Google Scholar, Villa M. D.M. EMBO J. 2006; PubMed Scopus Google Scholar), the of these the and thereby as a This in between family 3 and those of and suggested to that the of confer high selectivity family 3 over those other functionally related enzymes. and of the of we to a of N. 2006; 4: PubMed Scopus Google Scholar) 1). this of inhibitors in we found to be inhibitors of the NagZ from V. 1). the to in values for both human and N. 2006; 4: PubMed Scopus Google Scholar), as with NagZ 1). in are by NagZ as with the two human as a of the of the to NagZ, since is a that the selectivity as the as for which selectivity for NagZ over both human enzymes. the of the and the of the that and be by of the to with since this and the of on have been used to the of various genes and gene to of AmpC and resistance to the is E. a the ampC-ampR L. Normark S. S. A. PubMed Scopus Google Scholar). this since is genetically well and of various genes E. are we the ampC-ampR from the of C. and into the to This operon from a related of C. has been by Normark and L. Normark S. S. A. PubMed Scopus Google Scholar) to of AmpC that is greatly in the of various one mechanism some Gram-negative bacteria use to high level resistance to β-lactams is the of the which in of AmpC β-lactamase S. Normark S. J. Bacteriol. PubMed Scopus Google Scholar). the of NagZ inhibition on antibiotic resistance in both E. from the E. and the same lacking functional from the of and the inhibitors bacterial both wild-type and the strains in but antibiotics. found that growth of both the and the that the on is the of the on the of bacteria ampC-ampR using to various we the of certain β-lactams in with A series of clinically relevant β-lactam antibiotics, the generation antibiotic and the cephalosporins, and since they are used in antibiotic with are to these β-lactam are in with these to β-lactams in the of both that the has a on effectiveness of β-lactams against the AmpC these that is to to the NagZ The is a decrease in the of the 1,6-anhydro-MurNAc that in AmpC β-lactamase of bacterial strains against various β-lactam with and with the by in an using with of or with or The of with and with the by in an using with of or with or The of in a new this mechanism of we the of AmpC β-lactamase in of both wild-type and E. in the and of we AmpC β-lactamase expression by the with we AmpC β-lactamase from of the using the β-lactamase (Fig. In the of has on the of of at that is to AmpC with the of we we that NagZ inhibition using of the β-lactamase. The however, is with expression of AmpC by of AmpC expression is with the in values and the In those in β-lactam are on with but the level of E. lacking the ampC-ampR that NagZ inhibitors with in AmpC antibiotic resistance has on stable β-lactam or on small molecule inhibitors of AmpC β-lactamase that can in a with β-lactam antibiotics. One problem associated with AmpC inhibitors using the β-lactam is that these can increased β-lactamase expression Curr. Opin. Microbiol. 2005; 8: PubMed Scopus Google Scholar), although E. S. J. J. PubMed Scopus Google Scholar, D. R. J. 2005; PubMed Scopus Google Scholar). the and of resistance is a and for development of various to antibiotic Here we have that small molecule inhibition of NagZ, which to the inducer molecule, the of AmpC and thereby β-lactamase This strategy for β-lactam antibiotic since bacteria resistance to the inhibitors by the high of ampC or in that decrease of inhibitors the of the of the inducer molecule be and of AmpC be this strategy be against clinically relevant strains of bacteria in C. O. C. A. Antimicrob. Agents Chemother. 2005; PubMed Scopus Google Scholar, A. N.D. J. Antimicrob. Chemother. PubMed Scopus Google Scholar, N. O. M. M. N. Antimicrob. Agents Chemother. PubMed Scopus Google Scholar, L. A. Antimicrob. Agents Chemother. 2000; 44: PubMed Scopus Google these resistance in many strains of Gram-negative bacteria to many β-lactam antibiotics. and have that the mechanism by which P. an opportunistic β-lactam resistance is by of C. O. C. A. Antimicrob. Agents Chemother. 2005; PubMed Scopus Google Scholar, N. O. M. M. N. Antimicrob. Agents Chemother. PubMed Scopus Google Scholar, L. A. Antimicrob. Agents Chemother. 2000; 44: PubMed Scopus Google Scholar). The we that is at the β-lactam resistance of strains of bacteria. to a and of NagZ, inhibition of related human by the structure of NagZ V. in complex with using This structure the of a generation of and inhibitors but has in the development of inhibitors. of inhibitors having is by this The of such generation NagZ inhibitors some however, since inhibitors of NagZ in have the same in Indeed, using and in with β-lactam between each with in to those on with but and on values This is since has a that is that of and that some inhibitors, such as and to the bacterial to the by the of Gram-negative bacteria. that inhibitors have values in the range and of AmpC is we that considerable in is that of the to with for in P. to antibiotic resistance and the of various A. N. K. Antimicrob. Agents Chemother. 2005; PubMed Scopus Google Scholar). Accordingly, is that inhibition of NagZ in by thereby attenuating Sanders for the of and and the E. for of some of the bacterial strains used in this A. is for the of R. A. J. for on the and and at the of for with

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.