Antibiotic resistance in pathogenic and producing bacteria, with special reference to beta-lactam antibiotics.

Ogawara, H

doi:10.1128/mmbr.45.4.591-619.1981

Cited by 48 publications

(32 citation statements)

References 168 publications

(228 reference statements)

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“…The molecular weight was estimated to be 29,OOO±2,OOO. This value is close to those of .B-lactamases produced by other gram-positive bacteria (6). The enzyme showed activity over a range of pH values from 4.5 to 8.0, and its optimal pH was 6.6.…”

supporting

confidence: 80%

Purification and Some Properties of β‐Lactamase from Mycobacterium smegmatis

Kaneda

Yabu

1983

Microbiology and Immunology

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Mycobacteria which are usually penicillin resistant are known to produce f3-lactamases (I, 2). Kasik and his coworkers (3, 5) investigated some properties of f3-lactamases produced by Mycobacterium smegmatis, M. phlei, and M.fortuitum by using a crude enzyme from bacterial cells. The f3-lactamases from these rapid-growing mycobacteria showed broad substrate specificity. However, the nature of the purified enzyme from mycobacterial cells has not been studied. This paper describes the purification and some of the properties of an enzyme from M. smegmatis cells.M. smegmatis ATCC 607 was grown for three days at 37 C in a Sauton medium which contained (per liter): K 2HP04, 0.5 g; MgS0 4· 7H20, 0.5 g; L-asparagine, 4.0 g; sodium citrate, 3.0 g; ferric ammonium citrate, 0.05 g; and glycerol, 50.0 g (final pH 7.0). The cells were harvested on filter paper in a funnel, washed with water, and then suspended in ice-cold 0.07 M phosphate buffer, pH 6.6, at a concentration of 0.2 to 0.3 g (wet weight) per ml. The cell suspensions were disrupted by sonic treatment at 20,000 Hz for 10 min in an ice-water bath. The suspensions were centrifuged at 20,000 xg for 30 min at 0 C, and the supernatants were retained as the cell-free enzyme preparation. The enzyme preparation was brought to 15% saturation by the addition of solid (NH4)2S04. After 30 min the precipitate formed was removed by centrifugation and solid (NH 4hS04 was again added to the supernatant to 30% saturation. The resulting precipitate was collected by centrifugation and dissolved in 0.07 M phosphate buffer (pH 6.6). After dialysis against distilled water at 2 C, the enzyme solution was applied to a Sephadex G-75 column (3.2 X 50 em) previously equilibrated with 0

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supporting

confidence: 80%

Purification and Some Properties of β‐Lactamase from Mycobacterium smegmatis

Kaneda

Yabu

1983

Microbiology and Immunology

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“…Although chemotherapy can be beneficial in preventing and reducing disease, care must be taken to avoid unnecessary excessive manipulation of the flora, which could disrupt this delicate microbial community balance (121,144). Unwanted overgrowth of pathogenic strains or opportunists is a potential danger that may be viewed as a serious side effect of the chemical approach (27,126).…”

mentioning

confidence: 99%

Chemical agents to prevent and regulate plaque development

Fine¹

1995

Periodontology 2000

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“…The sequence of ala-ala-ala agrees with the 632 consensus ala-X-ala motif recognized by the signal peptidase of Streptomyces (Garcia-Gonzdlez et al, 1991) and other organisms (Watson, 1984 Time-course studies of N. lactamdurans 3-lactamase formation ( Figure 3) showed that the cell-bound enzyme is formed from the beginning of the culture, i.e. the bla is an 'early' gene which is expressed in a constitutive form ( Figure 3), as reported for the 3-lactamases of other species of Streptonyces (Ogawara, 1981), and its expression precedes those of the cephamycin biosynthetic genes encoding isopenicillin N synthase, isopenicillin N epimerase and deacetoxycephalosporin C synthase ( Figure 3). The lat gene, encoding lysine-6-amino transferase, an enzyme involved in precursor formation, is expressed early.…”

mentioning

confidence: 62%

Genes for a beta-lactamase, a penicillin-binding protein and a transmembrane protein are clustered with the cephamycin biosynthetic genes in Nocardia lactamdurans.

1993

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Three genes encoding a typical beta‐lactamase, a penicillin‐binding protein (PBP4) and a transmembrane protein are located in the cluster of cephamycin biosynthetic genes in Nocardia lactamdurans. The similarity of the N. lactamdurans beta‐lactamase to class A beta‐lactamases from clinical isolates supports the hypothesis that antibiotic resistance genes in pathogenic bacteria are derived from antibiotic‐producing organisms. The beta‐lactamase is secreted and is active against penicillins (including the biosynthetic intermediates penicillin N and isopenicillin N), but not against cephamycin C. The beta‐lactamase is synthesized during the active growth phase, prior to the formation of three cephamycin biosynthetic enzymes. The PBP of N. lactamdurans is a low‐M(r) protein that is very similar to DD‐carboxypeptidases of Streptomyces and Actinomadura. The pbp gene product expressed in Streptomyces lividans accumulates in the membrane fraction. By disruption of N. lactamdurans protoplasts, the PBP4 was shown to be located in the plasma membrane. Eight PBPs were found in the membranes of N. lactamdurans, none of which bind cephamycin C, which explains the resistance of this strain to its own antibiotic. A transmembrane protein encoded by the cmcT gene of the cluster also accumulates in the membrane fraction and is probably related to the control of synthesis and secretion of the antibiotic. A balanced synthesis of beta‐lactam antibiotics, beta‐lactamase and PBP is postulated to be critical for the survival of beta‐lactam‐producing actinomycetes.

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Antibiotic resistance in pathogenic and producing bacteria, with special reference to beta-lactam antibiotics.

Cited by 48 publications

References 168 publications

Purification and Some Properties of β‐Lactamase from Mycobacterium smegmatis

Purification and Some Properties of β‐Lactamase from Mycobacterium smegmatis

Chemical agents to prevent and regulate plaque development

Genes for a beta-lactamase, a penicillin-binding protein and a transmembrane protein are clustered with the cephamycin biosynthetic genes in Nocardia lactamdurans.

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