Nonspecific Induction of  -lactamase in Enterobacter cloacae

Cullman, Wolfgang; Dalhoff, A.; Dick, Wolfgang R.

doi:10.1099/00221287-130-7-1781

Cited by 28 publications

(6 citation statements)

References 7 publications

(14 reference statements)

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“…These enzymes are generally inducible, with the exception of the AmpC ␤-lactamase of E. coli, which is produced constitutively at low levels (8,13). Cefoxitin is a potent inducer of AmpC production (21).…”

Section: Discussionmentioning

confidence: 99%

Extended-Spectrum β-Lactamases in Ireland, Including a Novel Enzyme, TEM-102

Morris¹,

O’Hare²,

Glennon

et al. 2003

Antimicrob Agents Chemother

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Organisms producing extended-spectrum ␤-lactamases (ESBLs) have been reported in many countries, but there is no information on the prevalence of ESBL-producing members of the family Enterobacteriaceae in Ireland. A total of 925 isolates of ampicillin-resistant members of the Enterobacteriaceae were received from six hospitals in Ireland over a 3-year period from September 1996 to September 1999. Isolates were screened for ESBL production by the double-disk diffusion (DDD) method. DDD-positive isolates that were (i) confirmed as ESBL producers by National Committee for Clinical Laboratory Standards (NCCLS) confirmatory testing and (ii) susceptible to cefoxitin by disk diffusion were considered ESBL producers. By these criteria, 27 (3%) of the ampicillin-resistant members of the Enterobacteriaceae studied were categorized as ESBL producers. Molecular typing suggested that some intra-and interhospital spread of ESBL-producing isolates had occurred. DNA sequencing of amplified bla TEM and bla SHV genes resulted in the detection of a novel bla TEM ESBL gene, bla TEM-102 in two isolates (Klebsiella pneumoniae and Enterobacter cloacae) received from the same hospital but isolated from different patients. The study suggests dissemination of ESBL-producing bacteria within the health care system in Ireland and emphasizes the need for measures to control such spread.

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Section: Discussionmentioning

confidence: 99%

Extended-Spectrum β-Lactamases in Ireland, Including a Novel Enzyme, TEM-102

Morris¹,

O’Hare²,

Glennon

et al. 2003

Antimicrob Agents Chemother

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“…The level of AmpE in the presence of the AmpR transcriptional regulator affects the basal level of BLA expression in the absence of AmpD (16). In addition to induction by certain P-lactam antibiotics, BLA induction has been reported with diaminopimelic acid (25), glycine (7)(8)(9), D-alanine (5), and some other nonspecific agents which are neither ,-lactam antibiotics nor usual components of peptidoglycan (4). In Enterobacter cloacae, BLA can also be induced by D-methionine (21).…”

Section: I8-lactamase Inductionmentioning

confidence: 99%

Induction of a class I beta-lactamase from Citrobacter freundii in Escherichia coli requires active ftsZ but not ftsA or ftsQ products

Ottolenghi

Ayala

1991

Antimicrob Agents Chemother

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A possible connection between septation/division and induction of cloned ampC ,-lactamase was investigated. When aftsZ84(Ts) mutant of Escherichia coli carrying ampR-ampC from Citrobacterfreundii was grown at the restrictive temperature (42°C), induction of P-lactamase by cefoxitin was inhibited by about 80%.Inhibition was virtually complete when a ftsZ84(Ts) mutant of different genetic background was tested. Although somewhat delayed, the induction of ,I-lactamase in transformed ftsA(Ts) and ftsQ(Ts) mutants was similar to that observed in wild-type transformants. These results imply that FtsZ is involved in the process of I8-lactamase induction.Some nonspecific inducers as well as some ,-lactam antibiotics have been shown to induce class I P-lactamase (BLA) in many gram-negative organisms (24). The molecular basis for this induction is still not completely understood, but a number of genes which regulate it have been described. First, there is ampR, which is essential for inducibility and closely linked with the structural gene ampC. AmpR was described as the transcriptional regulator of ampC (14). Korfmann and Sanders have described ampG, the expression of which is essential for the induction of BLA (11).Two genes which have regulatory properties but which are not essential for BLA production have also been described: ampD (15), whose 20.5-kDa, cytoplasmically located product down-regulates the production of BLA, and the closely linked ampE (16), whose 32.1-kDa product is located in the cytoplasmic membrane. The level of AmpE in the presence of the AmpR transcriptional regulator affects the basal level of BLA expression in the absence of AmpD (16). In addition to induction by certain P-lactam antibiotics, BLA induction has been reported with diaminopimelic acid (25), glycine (7-9), D-alanine (5), and some other nonspecific agents which are neither ,-lactam antibiotics nor usual components of peptidoglycan (4). In Enterobacter cloacae, BLA can also be induced by D-methionine (21).Experiments with a strain of E. cloacae inducible for BLA and a semiconstitutive derivative showed that nalidixic acid was capable of reducing, although not completely eliminating, the production of BLA (20a). Nalidixic acid induces the SOS response. An element of this response is the inhibition of FtsZ (SulB) by the product of sulA, resulting in cell filamentation (17). FtsZ has been suggested to have a role in the localization and maturation of periseptal annuli, which are the first differentiated structures at future division sites (3). Concurrently with BLA induction, significant morphological changes are elicited by D-methionine. These changes include the formation of forms in which the inhibition of septa is apparent (21). These changes, together with the results from the nalidixic acid studies, suggest that BLA induction might be related to the ability of the cell to carry out septation and/or division in a balanced manner. In this * Corresponding author. model, nalidixic acid would inhibit induction by causing inactivation or ...

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“…D-Methionine (D-Met) and D-tryptophan (D-Trp) also induce BLA in E. cloacae (13). Other nonspecific additions to the medium have been shown to influence the induction of this enzyme (4,5,11).In the present paper, we show that when E. cloacae is induced to produce AmpC BLA by Gly, D-Met, or D-Trp, there are alterations in the proportion and cross-linking of the tripeptide moieties of the peptidoglycan. When D-Met is used as the inducing agent, morphologic changes which eventually culminate in the production of large round bodies showing cytoplasmic but not cell division are seen.…”

mentioning

confidence: 61%

Peptidoglycan tripeptide content and cross-linking are altered in Enterobacter cloacae induced to produce AmpC beta-lactamase by glycine and D-amino acids

1993

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Induction of AmpC 1-lactamase in Enterobacter cloacae ATCC 13047 by D-methionine, glycine, or D-tryptophan was accompanied by alterations in peptidoglycan composition and structure; in the case of D-methionine, it was also accompanied by morphologic changes. A decrease in peptidoglycan tripeptides was seen. With glycine, there was an increase in the proportion of diaminopimelic-diaminopimelic cross-links. The possible implications of these changes for 1-lactamase induction are discussed.Nonspecific inducers have been shown to induce class I P-lactamase (BLA) in gram-negative organisms. High levels of glycine (Gly), which are known to alter the structure of the peptidoglycan (9), induce BLA in Enterobacter cloacae (6, 7). Induction in liquid medium by Gly has been reported for E. cloacae (13) and for Escherichia coli transformed with pNU305 by Martin and Schmidt (12). D-Methionine (D-Met) and D-tryptophan (D-Trp) also induce BLA in E. cloacae (13). Other nonspecific additions to the medium have been shown to influence the induction of this enzyme (4,5,11).In the present paper, we show that when E. cloacae is induced to produce AmpC BLA by Gly, D-Met, or D-Trp, there are alterations in the proportion and cross-linking of the tripeptide moieties of the peptidoglycan. When D-Met is used as the inducing agent, morphologic changes which eventually culminate in the production of large round bodies showing cytoplasmic but not cell division are seen.E. cloacae ATCC 13047 grown overnight in modified Torriani medium (16) with 0.15 M NaH2PO4 rather than glycerol phosphate and 0.002 M KCl was diluted to an optical density at 550 nm of 0.04 to 0.06 in fresh prewarmed medium and was incubated with agitation at 370C to an optical density at 550 nm of ca. 0.3. Baseline samples were taken. The culture was split, and D-Met (0.013 M), glycine (0.05 M), or D-Trp (0.02 M) was added. Aliquots were taken after 2 h, and the remaining cultures were diluted 1:2 in prewarmed medium containing the appropriate amino acid. Additional aliquots were taken after 1 h and again at 2 h. Experiments with D-Met were terminated at this point. Cultures with Gly or D-Trp were again diluted 1:2, and the incubation continued for 1 h more.BLA was assayed in triplicate as previously described (14). Cephaloridine was used as the substrate for the assay of the enzyme induced by D-Met or glycine or under control conditions. Nitrocefin was used as the substrate for the experiments with D-Trp. Protein assay was by the method described by Bradford (2).In early experiments, cultures maintained without dilution showed only a two-to threefold induction of BLA after 7 to 8 h (data not shown). In the cases of D-Met and D-Trp, * Corresponding author. exponential growth maintained by one twofold dilution of the culture increased the levels of BLA to final levels that were 10-to 20-fold higher than the base level. With Gly, significant increases were not seen until the 4th h of incubation (two dilutions), when the levels reached were similar to those attained with the D-...

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Nonspecific Induction of -lactamase in Enterobacter cloacae

Cited by 28 publications

References 7 publications

Extended-Spectrum β-Lactamases in Ireland, Including a Novel Enzyme, TEM-102

Extended-Spectrum β-Lactamases in Ireland, Including a Novel Enzyme, TEM-102

Induction of a class I beta-lactamase from Citrobacter freundii in Escherichia coli requires active ftsZ but not ftsA or ftsQ products

Peptidoglycan tripeptide content and cross-linking are altered in Enterobacter cloacae induced to produce AmpC beta-lactamase by glycine and D-amino acids

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