Beta-lactamase production and genetic location in Staphylococcus aureus: introduction of a β-lactamase plasmid in strains of phage group II

Skov, Robert; Williams, T; Pallesen, Lars; Rosdahl, Vibeke Thamdrup; Espersen, Frank

doi:10.1016/0195-6701(95)90151-5

Cited by 11 publications

(5 citation statements)

References 26 publications

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“…The A, C, and D types are commonly encoded on plasmids while blaZ gene for type B enzymes is often present on the chromosome 21; 22. Despite the separation into distinct types, the S. aureus blaZ encoded enzymes are very similar; with >90% amino acid sequence identity across the various types 23.…”

Section: Introductionmentioning

confidence: 99%

Identification of a β-Lactamase Inhibitory Protein Variant That Is a Potent Inhibitor of Staphylococcus PC1 β-Lactamase

Yuan

Chow

Huang

et al. 2011

Journal of Molecular Biology

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The β-lactamase inhibitory protein (BLIP) binds and inhibits a diverse collection of class A β-lactamases. Widespread resistance to β-lactam antibiotics currently limits treatment strategies for Staphylococcus infections. The goal of this study was to determine the binding affinity of BLIP for S. aureus PC1 β-lactamase and to identify mutants that alter binding affinity. The BLIP inhibition constant (Ki) for the PC1 β-lactamase was measured at 350 nM and isothermal titration calorimetry (ITC) experiments indicated a binding constant (Kd) of 380 nM. A total of 23 residue positions in BLIP that contact β-lactamase were randomized and phage display was used to sort the libraries for tight binders to immobilized PC1 β-lactamase. The BLIP K74G mutant was the dominant clone selected and it was found to inhibit the PC1 β-lactamase with a Ki of 42 nM while calorimetry indicated a Kd of 26 nM. Molecular modeling studies suggested BLIP binds weakly to the PC1 β-lactamase due to the presence of alanine at position 104 of PC1. This position is occupied by glutamate in the TEM-1 enzyme where it forms a salt bridge with BLIP residue Lys74 that is important for the stability of the complex. This hypothesis was confirmed by showing that the A104E PC1 enzyme binds BLIP with 15-fold greater affinity than wild type PC1 β-lactamase. Kinetic measurements indicated similar association rates for all complexes with the variation in affinity due to altered dissociation rate constants suggesting changes in short-range interactions are responsible for the altered binding properties of the mutants.

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Section: Introductionmentioning

confidence: 99%

Identification of a β-Lactamase Inhibitory Protein Variant That Is a Potent Inhibitor of Staphylococcus PC1 β-Lactamase

Yuan

Chow

Huang

et al. 2011

Journal of Molecular Biology

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“…Combined with the findings of this study and the original report of ␤-lactamase variants in S. aureus by Richmond in 1965 (27) in which the type C ␤-lactamase was found among phage group I and III isolates but not in phage group II isolates, it appears that the type B gene has been present in phage group II isolates since at least the 1960s and that the type C gene has appeared in this phage group relatively recently. Furthermore, the 21-kb plasmid on which the type C gene is carried in phage group II isolates has a distinctive endonuclease restriction pattern and appears to be found commonly among clinical isolates of S. aureus throughout the world (5,33). All of the phage group II type C ␤-lactamase-producing isolates evaluated in this study contained this 21-kb plasmid.…”

Section: Discussionmentioning

confidence: 82%

“…In contrast, the type B gene is chromosomal, a finding suspected by earlier investigators on the basis of their inability to cure such isolates of ␤-lactamase production (6-9, 24, 30, 31, 33) and shown more convincingly with the Southern hybridization studies performed as part of this evaluation. Using curing experiments as an indicator of whether blaZ is located on a plasmid or the chromosome, Skov et al (33) have reported that all phage group II isolates recovered prior to 1977 harbored blaZ on the chromosome, whereas blaZ was plasmid borne in the large majority of phage group II isolates recovered in recent years. Combined with the findings of this study and the original report of ␤-lactamase variants in S. aureus by Richmond in 1965 (27) in which the type C ␤-lactamase was found among phage group I and III isolates but not in phage group II isolates, it appears that the type B gene has been present in phage group II isolates since at least the 1960s and that the type C gene has appeared in this phage group relatively recently.…”

Section: Discussionmentioning

confidence: 99%

“…Regarding the long-standing impression that phage group II and type B ␤-lactamase-producing isolates of S. aureus make less ␤-lactamase than other staphylococcal isolates (31) and the observation by Skov et al (33) that phage group II isolates in which blaZ is located on the chromosome exhibit only half the penicillinase activity of those in which blaZ is plasmid borne, it is noteworthy that the amount of enzyme activity detected depends upon the ␤-lactam used as the substrate. For example, although our findings obtained with benzylpenicillin as the substrate confirm that phage group II isolates with blaZ on their chromosomes exhibit lower ␤-lactamase activities than isolates in which blaZ is plasmid borne, these differences disappear when cephaloridine or nitrocefin is used to quantify ␤-lactamase activity (Table 1).…”

Section: Discussionmentioning

confidence: 99%

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Characterization of a Chromosomal Gene Encoding Type B β-Lactamase in Phage Group II Isolates of Staphylococcus aureus

Voladri

Kernodle

1998

Antimicrob Agents Chemother

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In contrast to most Staphylococcus aureus isolates in which the gene for staphylococcal β-lactamase (blaZ) is plasmid borne, isolates typeable by group II bacteriophages frequently carry blaZ on the chromosome. Furthermore, the chromosomal gene encodes the type B variant of staphylococcal β-lactamase for which the nucleotide and deduced amino acid sequences have not yet been reported. To better understand β-lactamase production among phage group II staphylococci and the nature of the type B β-lactamase, we determined the type and amount of enzyme produced by 24 phage group II isolates. Of these isolates, 1 did not produce β-lactamase, 8 produced the type B enzyme, and 15 produced the type C enzyme. In all eight type B β-lactamase-producing isolates, blaZ was located on the chromosome. This was in contrast to the type C β-lactamase-producing isolates, in which blaZ was located on a 21-kb plasmid. The nucleotide sequence corresponding to the leader peptide and the N-terminal 85% of the mature exoenzyme form of type BS. aureus was determined. The deduced amino acid sequence revealed 3 residues in the leader peptide and 12 residues in the exoenzyme portion of the β-lactamase that differ from the prototypic type A β-lactamase sequence. These include the serine-to-asparagine change at residue 216 found in the kinetically similar type C enzyme, a threonine-to-lysine change at residue 128 close to the SDN loop (residues 130 to 132), and several substitutions not found in any of the other staphylococcal β-lactamases. In summary, modern isolates ofS. aureus typeable by group II phages produce type B or type C staphylococcal β-lactamase. The type B gene resides on the chromosome and has a sequence that, when compared to the sequences of the other staphylococcal β-lactamases, corresponds well with its kinetic properties.

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“…13 However, some S. aureus isolates produce β-lactamase despite penicillin MICs of 0.125 or 0.064 mg/L. 10,14,15 This has led to mistrust of penicillinsusceptibility testing results in S. aureus. Thus, CLSI guidelines recommend testing for βlactamase production and/or to confirm the absence of blaZ by PCR testing in all apparently penicillin-susceptible isolates.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of methods for detection of β-lactamase production in MSSA

Skov

Lonsway

Larsen

et al. 2021

Journal of Antimicrobial Chemotherapy

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Objectives Correct determination of penicillin susceptibility is pivotal for using penicillin in the treatment of Staphylococcus aureus infections. This study examines the performance of MIC determination, disc diffusion and a range of confirmatory tests for detection of penicillin susceptibility in S. aureus. Methods A total of 286 consecutive penicillin-susceptible S. aureus blood culture isolates as well as a challenge set of 62 MSSA isolates were investigated for the presence of the blaZ gene by PCR and subjected to penicillin-susceptibility testing using broth microdilution MIC determination, disc diffusion including reading of the zone edge, two nitrocefin tests and the cloverleaf test. Results Using PCR-based detection of blaZ as the gold standard, both broth microdilution MIC testing and disc diffusion testing resulted in a relatively low accuracy (82%–93%) with a sensitivity ranging from 49%–93%. Among the confirmatory tests, the cloverleaf test performed with 100% accuracy, while zone edge interpretation and nitrocefin-based tests increased the sensitivity of β-lactamase detection to 96%–98% and 82%–96% when using MIC determination or disc diffusion as primary test, respectively. Conclusions This investigation showed that reliable and accurate detection of β-lactamase production in S. aureus can be obtained by MIC determination or penicillin disc diffusion followed by interpretation of the zone edge as a confirmatory test for apparently penicillin-susceptible isolates. The more cumbersome cloverleaf test can also be used. Nitrocefin-based tests should not be used as the only test for confirmation of a presumptive β-lactamase-negative isolate.

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Beta-lactamase production and genetic location in Staphylococcus aureus: introduction of a β-lactamase plasmid in strains of phage group II

Cited by 11 publications

References 26 publications

Identification of a β-Lactamase Inhibitory Protein Variant That Is a Potent Inhibitor of Staphylococcus PC1 β-Lactamase

Identification of a β-Lactamase Inhibitory Protein Variant That Is a Potent Inhibitor of Staphylococcus PC1 β-Lactamase

Characterization of a Chromosomal Gene Encoding Type B β-Lactamase in Phage Group II Isolates of Staphylococcus aureus

Evaluation of methods for detection of β-lactamase production in MSSA

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