Gentamicin resistance in strains of Pseudomonas aeruginosa mediated by enzymic N-acetylation of the deoxystreptamine moiety

Brzezinska, Maria Swiontek; Benveniste, Raoul Ė.; Davies, Julian; Daniels, Peter J. L.; Weinstein, Jay

doi:10.1021/bi00755a013

Cited by 108 publications

(45 citation statements)

References 10 publications

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“…If, however, the number the generations of strain 280 (R931) exceeded 10, the transfer frequency was 9 x 10-5. These results are very similar to those obtained in the Col I system in which conjugating ability is subject to repression (30) (6). One possible explanation for these observations could be a reduction in the relative content of R-factor DNA in strain 280 due to its restriction to a small percentage of the population or to a reduction in copies of R factor per cell.…”

Section: Resultssupporting

confidence: 85%

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Characteristics of R931 and Other Pseudomonas aeruginosa R Factors

Bryan

Semaka

Elzen

et al. 1973

Antimicrob Agents Chemother

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R factors were detected in 3.3% of 233 hospital isolates of Pseudomonas aeruginosa using P. aeruginosa recipients in conjugations. Transferred markers included streptomycin, tetracycline, and sulfonamide resistance. Gentamicin resistance was transferred from two strains previously shown to acetylate gentamicin. A group of R factors exemplified by R931 were characterized by failure to transfer to Escherichia coli recipients. Such R factors formed a single compatibility group when examined in a P. aeruginosa recipient. Other P. aeruginosa R factors, including RP4, showed stable coexistence with the R931 group. It is proposed that RP4 and similar R factors be members of the P-1 compatibility group and that R931, R3108, R209, and R130 be members of a group termed P-2. The buoyant densities of all R factors examined were similar, about 1.716 to 1.719 g/cm3. The content of R-factor deoxyribonucleic acid (DNA) relative to the total DNA varied among the different R factors, ranging from about 18 ± 2% in logphase cells of 931 (R931) to undetectable for 679 (R679). However, R679, which transferred from strain 679 at extremely low and irregular frequencies to an E. coli host, was shown to represent about 4% R-factor DNA in that host. The relative DNA content of R931 appeared to decline in the stationary growth phase of 931 (R931) or 280 (R931). R931 covalently closed circular DNA was isolated by ethidium bromide-CsCl gradient centrifugation and examined by electron microscopy. Two major molecular distributions existed, having contour lengths of 0.5 and 12.4 ,um. The molecular weights were estimated to be 106 and 25 x 106. Both molecules were under relaxed replication control. R factor R931 exists as a naturally occurring high-frequency transfer system in P. aeruginosa strains 931 and 1310. However, in strain 280 it acts as if subject to fertility repression. Other members of the P-2 compatibility group also are high-frequency transfer systems in the natural host and in strain 1310. RP4 is restricted from recipient strain 1310. Some additional recipient effects were noted in that strains 1310 or 280 sometimes differed in recipient effectiveness with a given donor. Agglutination reactions with absorbed antiserum were able to distinguish between two members of the same R-factor compatibility group, R931 and R3108.Previous evidence (5) strongly suggested that at least some Pseudomonas R factors, including R931, are host-restricted. Such R factors contrast with other Pseudomonas R factors, described by several workers (11,14,17,27,31), which seem to be freely transferable between P. aeruginosa and members of the Enterobacteriaceae. Grinsted et al. (17) and Datta et al. (11) examined some of the properties of the latter R factors, but the former have not been described in detail. The work in this paper describes some of the characteristics of partially or completely host-restricted Pseudomonas R factors. MATERIALS AND METHODSOrganisms. All P. aeruginosa strains were originally obtained from clinical specimens and identified a...

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Section: Resultssupporting

confidence: 85%

“…It is of interest that, although these strains (PS-130, PS-209) have been shown to contain kanamycin phosphotransferase (6), there is no evidence of transfer of resistance to kanamycin to either recipient strain (Table 3). Also, a third strain acetylating gentamicin has not been found to transfer gentamicin resistance.…”

Section: Resultsmentioning

confidence: 99%

Characteristics of R931 and Other Pseudomonas aeruginosa R Factors

Bryan

Semaka

Elzen

et al. 1973

Antimicrob Agents Chemother

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“…P. aeruginosa is known to be resistant to aminoglycosides owing to the enzymatic N acetylation. 6,22,23) Our study showed that the P. aeruginosa strains tested have the aacA4 gene cassette and that the gene in this cassette was 100% identical to the aac(6 )-Ib gene encoding an aminoglycoside 6 -N-acetyltransferase. The enzymes that modify the 6 position (6 -N acetyltransferase [AAC (6 )]) are the most common acetyltranferases in multidrug-resistant bacteria including P. aeruginosa.…”

Section: Discussionmentioning

confidence: 75%

A Plasmidic Class 1 Integron from Five Pseudomonas aeruginosa Clinical Strains Harbored aacA4 and Nonsense-mutated cmlA1 Gene Cassettes

Shi

Yamasaki

et al. 2007

JOURNAL OF HEALTH SCIENCE

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Five strains of multidrug-resistant Pseudomonas aeruginosa (P. aeruginosa) were isolated from inpatients at a local hospital in China. The most frequent resistance was to cefoperazone, ciprofloxacin, ceftriaxone, cefotaxime, gentamicin, piperacillin, trimethoprim sulfamethoxazole, and tobramycin. These strains were found to contain the class 1 integron, in which the 2360-bp gene cassettes were flanked by 5 -and 3 -conserved segments. Sequence analysis revealed that the gene cassettes contained aacA4 and cmlA1 genes; however, the latter gene had a nonsense mutation resulting in the production of a truncated protein. To the best of our knowledge, this is the first report of a nonsense mutation in the cmlA1 gene. Moreover, the P. aeruginosa strains showed identical profiles in pulsed-field gel electrophoresis, suggesting that they were derived from the same clone. These results emphasize the importance of controlling the spread of multidrug-resistant pathogens in hospitals.

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“…Its increased prevalence in morbidity and mortality has been greatly complicated by its resistance to several antibiotic agents. Investigators have searched for both intrinsic and extrinsic factors which may be responsible for this antibiotic resistance (3,4,10,12,16). Many strains of P. aeruginosa may possess a cell wall which acts as a permeability barrier for antibiotic penetration (13).…”

mentioning

confidence: 99%

Effect of Triethylenetetramine Dihydrochloride on the Antibiotic Susceptibility of Pseudomonas aeruginosa

Light

Riggs

1978

Antimicrob Agents Chemother

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Recently, Pseudomonas aeruginosa has become a major problem for both patients and clinicians. Its increased prevalence in morbidity and mortality has been greatly complicated by its resistance to several antibiotic agents. Investigators have searched for both intrinsic and extrinsic factors which may be responsible for this antibiotic resistance (3,4,10,12,16). Many strains of P. aeruginosa may possess a cell wall which acts as a permeability barrier for antibiotic penetration (13). Studies have shown that the chelating agent, ethylenediaminetetraacetic acid (EDTA), increases the susceptibility of P. aeruginosa to various antibiotics in vitro (1, 17). EDTA has been shown to increase cell wall permeability by removal of calcium, which is involved in essential cross-linkages and cell wall integrity (5,(7)(8)(9)14). However, due to the toxic properties of EDTA, its use in systemic therapy of P. aeruginosa infections has been limited (2). In contrast to EDTA, triethylenetetramine dihydrochloride (TRIEN dihydrochloride) has been shown to be a chelating agent of low toxicity (6). In addition, the compound has been noted to enhance the activity of carbenicillin against P. aeruginosa (15). The purpose of this study was to determine the efficacy of TRIEN dihydrochloride in enhancing the susceptibility of P. aeruginosa to carbenicillin and gentamicin. In a similar manner this experiment was performed in TSB containing 50% serum (vol/vol), which was designated TSB-50S. The concentration of TRIEN dihydrochloride was increased to 0.0100 M in these experiments because at lower concentrations when serum was added to the growth medium, there was no effect on the MIC of the antibiotic. This higher con-

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Gentamicin resistance in strains of Pseudomonas aeruginosa mediated by enzymic N-acetylation of the deoxystreptamine moiety

Cited by 108 publications

References 10 publications

Characteristics of R931 and Other Pseudomonas aeruginosa R Factors

Characteristics of R931 and Other Pseudomonas aeruginosa R Factors

A Plasmidic Class 1 Integron from Five Pseudomonas aeruginosa Clinical Strains Harbored aacA4 and Nonsense-mutated cmlA1 Gene Cassettes

Effect of Triethylenetetramine Dihydrochloride on the Antibiotic Susceptibility of Pseudomonas aeruginosa

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