Meningococcal penicillin G tolerance and binding proteins

Neirinck, L.G.; DeVoe, I W

doi:10.1111/j.1574-6968.1982.tb08656.x

Cited by 3 publications

(6 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Characterization of the PBPs of N. meningitidis has been limited to a single penicillin G-susceptible isolate (11). Our data are consistent with that report, since four PBPs were detected with a penicillin G concentration equivalent to the MIC for susceptible isolates (0.06 ,ig/ml) and a 30-min incubation time.…”

Section: Methodssupporting

confidence: 81%

“…Our data are consistent with that report, since four PBPs were detected with a penicillin G concentration equivalent to the MIC for susceptible isolates (0.06 ,ig/ml) and a 30-min incubation time. Comparison of the Mrs of the PBPs that we detected with those previously described is not possible because they were not reported (11) would have prevented loss of viability in the presence of penicillin G (11). The detection of PBP 3 of susceptible strains with the short incubation times in both studies and the inability to detect PBP 3 of our resistant isolates (with a 10-min incubation) suggest, respectively, that PBP 3 has a high affinity for penicillin and is an altered target.…”

Section: Methodsmentioning

confidence: 82%

“…Whole cells were used to study the acylation of the PBPs with penicillin; four strains for which penicillin G MICs equal 0.03, 0.06, 0.3, and 0.7 p.g/ml were examined. Each strain was grown in a 20-ml volume as described above, and 12 1.5-ml samples of each cell suspension were centrifuged, washed, and suspended in 80 of buffer; 11 concentrated samples of each cell suspension were labeled with increasing concentrations of 3H-labeled penicillin from 0.0006 to 15 p.g/ml for 10 min and processed as previously described (7,11). These assays were performed in duplicate.…”

Section: Methodsmentioning

confidence: 99%

“…3H-labeled penicillin G (0.06 p.g/ml, final concentration) was added to each sample, and samples were incubated at 37°C for 10 and 30 min. Cells were lysed as previously described (7,11), and equal amounts of protein from each strain were loaded into the lanes of a 10% polyacrylamide separating gel. Electrophoresis, fixation, enhancement, and fluorography were performed as previously described (7).…”

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Relative penicillin G resistance in Neisseria meningitidis and reduced affinity of penicillin-binding protein 3

Mendelman

Campos

Chaffin

et al. 1988

Antimicrob Agents Chemother

View full text Add to dashboard Cite

We examined clinical isolates of Neisseria meningitidis relatively resistant to penicillin G (mean MIC, 0.3 ,ug/ml; range, 0.1 to 0.7 ,ug/ml), which were isolated from blood and cerebrospinal fluid for resistance mechanisms, by using susceptible isolates (mean MIC, c0.06 ,ug/ml) for comparison. The resistant strains did not produce detectable I-lactamase activity, otherwise modify penicillin G, or bind less total penicillin.Penicillin-binding protein (PBP) 3 of the six resistant isolates tested uniformly bound less penicillin G in comparison to the same PBP of four susceptible isolates. Reflecting the reduced binding affinity of PBP 3 of the two resistant strains tested, the amount of 3H-labeled penicillin G required for half-maximal binding was increased in comparison with that of PBP 3 of the two susceptible isolates. We conclude that the mechanism of resistance in these meningococci relatively resistant to penicillin G was decreased affinity of PBP 3.Concurrent with an epidemic of meningococcal disease in Spain from 1978 to 1985, the National Reference Laboratory began surveillance which included screening for penicillin G susceptibility. Of 3,264 strains isolated from blood or cerebrospinal fluid during those years, only one resistant isolate was observed in the final year (12). Subsequently, in the first six months of 1986, 9 (5%) of 168 invasive isolates were found to be relatively resistant to penicillin G. More worrisome is the decreased susceptibility of these strains to other P-lactams (2). The emergence of relatively penicillin-Gresistant strains in a short period of time suggests the possibility of a mutational event and dispersion of a clone or acquisition of a mobile genetic element harboring resistance. We sought to define the mechanism of resistance in these straihs. Possibilities include the production of ,B-lactamase, other enzymatic modification of the penicillin G molecule, acqcuisition of relative impermeability to penicillin G, or insensitivity of the cellular targets, the penicillin-binding proteins (PBPs). Each mechanism has different implications as to the activity of alternative antibiotics against these strains. MATERIALS AND METHODSStrains. All 16 resistant (defined as those growing on media containing 0.1 jig of penicillin G per ml) strains were isolated from cerebrospinal fluid or blood during 1985 and 1986 in Spain and were identified as Neisseria meningitidis by standard methods (9); 11 were serogroup B, 4 were serogroup C, and 1 was autoagglutinable. Twelve strains identified as susceptible (no growth on media containing 0.1 jig of penicillin G per ml) isolated in the same geographic area of Spain were used for comparisons; 8 were serogroup B, and 4 were serogroup C. All strains were stored in 50% tryptic soy broth (Difco Laboratories, Detroit, Mich.) containing 10% glycerol at -70°C.Enzymatic modification. P-Lactamase activity was sought by two methods; the rapid acidimetric assay with penicillin * Corresponding author. G (Sigma Chemical Co., St. Louis, Mo.) as substrate and phe...

show abstract

Section: Methodssupporting

confidence: 81%

Section: Methodsmentioning

confidence: 82%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Relative penicillin G resistance in Neisseria meningitidis and reduced affinity of penicillin-binding protein 3

Mendelman

Campos

Chaffin

et al. 1988

Antimicrob Agents Chemother

View full text Add to dashboard Cite

show abstract

“…This may first occur at the site of septum formation and it correlates with loss in viability ( I 9). The plasmolysis increases when higher penicillin concentrations are used, but the initial phenomenon at the site of septum formation is independent of penicillin concentrations above the MIC value ( 19). Penicillin-treated cells may be protected against lysis and loss in viability, but cell division no longer occurs (1 9).…”

Section: Effect Of Penicillin On the Morphologymentioning

confidence: 99%

EFFECT OF PENICILLIN ON THE MORPHOLOGY OF A NEISSERIA MENINGITIDIS STRAIN LIBERATING FREE ENDOTOXIN

Andersen

Skjørten

Solberg³

1981

Acta Pathologica Microbiologica Scandinavica Section B Microbio

View full text Add to dashboard Cite

An endotoxin‐liberating strain of Neisseria meningitidis plasmolysed extensively after 2h of exposure to 100 times MIC values of benzylpenicillin. The peptidoglycan layer could be demonstrated after 2h of treatment in places where the cytoplasm still was close to the cell wall. After 20h, however, this layer was complete undetectable. In untreated cells the peptidoglycan layer could more easily be found in older cultures than in very young cultures. An increased adhesiveness and aggregation to other bacterial cells and to cell wall material could be observed after 2h of penicillin treatment, and more pronouncedly after 20h. A high yield of free cell wall material could be demonstrated after 2h of penicillin treatment. This corresponded well to an increased content of free endotoxin in the filtrates from the cell cultures treated with penicillin, compared to untreated controls. After 20h of treatment, free cell wall material had formed large aggregates or was adherent to the cell walls of ghost cells. The corresponding endotoxin analysis showed a reduced content of filtrable endotoxin. Possible implications of the structural changes in relation to penicillin treatment of patients are discussed.

show abstract

Genetic diversity of penicillin G-resistant Neisseria meningitidis from Spain

et al. 1989

View full text Add to dashboard Cite

Genotypic and phenotypic diversity among 16 penicillin G-resistant (Penr) isolates of Neisseria meningitidis recovered from human blood or cerebrospinal fluid in Spain was compared with that among 12 penicillinsusceptible (Pens) isolates by the use of multilocus enzyme electrophoresis, serotyping, auxotroph testing in chemically defined media, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of penicillin-binding proteins (PBPs). Thirteen distinctive multilocus enzyme genotypes (electrophoretic types [ETs]) were identified among the 28 isolates. There was slightly less genetic diversity among the eight ETs of Penr isolates (H = 0.385) than among the eight ETs of Pens isolates (H = 0.431). Cluster analysis demonstrated two distinctive complexes of ETs and one ET that was not closely related to either complex. The possibility of a singular clonal origin of penicillin G-resistant isolates was excluded by the observations that resistance occurred in isolates of each of the two distantly related complexes of ETs, that three of the four ETs represented by multiple isolates included both susceptible and resistant strains, and that serotypes and growth requirements were not associated with the resistance phenotype. The 28 isolates showed a relatively homogeneous pattern of four PBPs, with apparently reduced penicillin G binding by PBP 3 of the Penr isolates. 1025

show abstract

Meningococcal penicillin G tolerance and binding proteins

Cited by 3 publications

References 15 publications

Relative penicillin G resistance in Neisseria meningitidis and reduced affinity of penicillin-binding protein 3

Relative penicillin G resistance in Neisseria meningitidis and reduced affinity of penicillin-binding protein 3

EFFECT OF PENICILLIN ON THE MORPHOLOGY OF A NEISSERIA MENINGITIDIS STRAIN LIBERATING FREE ENDOTOXIN

Genetic diversity of penicillin G-resistant Neisseria meningitidis from Spain

Contact Info

Product

Resources

About