Enhancement by cationic compounds of the growth inhibitory effect of novobiocin on Escherichia coli

Modha, Jayshree; Barrett‐Bee, Keith; Rowbury, R. J.

doi:10.1111/j.1472-765x.1989.tb00252.x

Cited by 8 publications

(8 citation statements)

References 9 publications

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“…This has been shown to be the case with the enzymatic derivative of PMB, PMB nonapeptide, whose antimicrobial activity is markedly reduced with respect to PMB while, as a permeabilizer, it retains the potency of its parent molecule ([ 41 ], and our own unpublished results). Observations similar to ours have been reported by others using agents of disparate nature including spermidine and other polyamines ([ 42 , 43 ], cholic acid derivatives [ 44 ] as well as cationic steroid antibiotics [ 45 ].…”

Section: Discussionsupporting

confidence: 88%

Comparative analysis of selected methods for the assessment of antimicrobial and membrane-permeabilizing activity: a case study for lactoferricin derived peptides

et al. 2008

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Background: Growing concerns about bacterial resistance to antibiotics have prompted the development of alternative therapies like those based on cationic antimicrobial peptides (APs). These compounds not only are bactericidal by themselves but also enhance the activity of antibiotics. Studies focused on the systematic characterization of APs are hampered by the lack of standard guidelines for testing these compounds. We investigated whether the information provided by methods commonly used for the biological characterization of APs is comparable, as it is often assumed. For this purpose, we determined the bacteriostatic, bactericidal, and permeability-increasing activity of synthetic peptides (n = 57; 9-13 amino acid residues in length) analogous to the lipopolysaccharide-binding region of human lactoferricin by a number of the most frequently used methods and carried out a comparative analysis.

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Section: Discussionsupporting

confidence: 88%

Comparative analysis of selected methods for the assessment of antimicrobial and membrane-permeabilizing activity: a case study for lactoferricin derived peptides

et al. 2008

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“…A possible reason for this is that SPP forms a complex with gentamicin ; SPP complexes with other drugs and forms an insoluble precipitate with chlorhexidine ( Ayres 1995). The high potentiating action of SPP had also been shown by other workers ( Vaara 1992) while Modha et al . (1989 ) demonstrated that cationic compounds such as spermidine could increase the growth‐inhibitory properties of novobiocin against E. coli .…”

Section: Discussionsupporting

confidence: 79%

“…with concnetration ----------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------------For key, see Table 1. insoluble precipitate with chlorhexidine (Ayres 1995). The high potentiating action of SPP had also been shown by other workers (Vaara 1992) while Modha et al (1989) demonstrated that cationic compounds such as spermidine could increase the growth-inhibitory properties of novobiocin against E. coli.…”

Section: Discussionmentioning

confidence: 59%

Effect of permeabilizers on antibiotic sensitivity ofPseudomonas aeruginosa

Ayres

Furr

Russell

1999

Letters in Applied Microbiology

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Agents which had previously been shown to act as permeabilizers against Pseudomonas aeruginosa or other Gram‐negative bacteria were tested to determine whether susceptibility to various antibiotics could be increased. In the absence of a permeabilizer, Ps. aeruginosa was resistant to several hydrophobic antibiotics and vancomycin, but not to gentamicin. Tartaric and gluconic acids had weak potentiating activity, whereas ethylenediamine tetraacetic acid and citric acid were more effective permeabilizers. However, sodium polyphosphate enhanced the activity of erythromycin, fucidin, novobiocin, rifampicin and methicillin ; vancomycin was unaffected and the activity of gentamicin was reduced considerably.

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“…Several agents have been used in attempts to alter the OM permeabilities of gram-negative bacteria (4); these include EDTA and lysozyme (2, 13), sodium hexametasulfonate (26), detergents like sodium dodecyl sulfate (1) and deoxycholate, as well as permeabilizing portions of antibiotics such as polymyxin B (18,23) and other compounds containing positively charged amino groups, such as spermidine and lysine (24) and methylglyoxal bis-guanylhydrazone (16).…”

Section: Discussionmentioning

confidence: 99%

Synergy between Polyethylenimine and Different Families of Antibiotics against a Resistant Clinical Isolate of Pseudomonas aeruginosa

Khalil

Chen

Riffon

et al. 2008

Antimicrob Agents Chemother

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The in vitro activities of 10 families of antimicrobial agents alone and in combination with a synthetic polycationic polymer, polyethylenimine (PEI), against a resistant clinical isolate of Pseudomonas aeruginosa were investigated by MIC assays, checkerboard testing, and killing curve studies. At a concentration of 250 nM, PEI (10 kDa) was not directly bactericidal or bacteriostatic; but when it was used in combination with novobiocin, ceftazidime, ampicillin, ticarcillin, carbenicillin, piperacillin, cefotaxime, chloramphenicol, rifampin, or norfloxacin, it significantly reduced the MICs of these antibiotics by 1.5-to 56-fold. However, the MICs of aminoglycosides, polymyxins, and vancomycins were increased by 1.2-to 5-fold when these drugs were combined with PEI; and the MICs of tetracycline, erythromycin, ciprofloxacin, and ofloxacin were not affected when these drugs were combined with PEI. In the killing curve studies, combinations of PEI with novobiocin, ceftazidime, chloramphenicol, or rifampin resulted in 5-to 8-log 10 CFU/ml reductions in bacterial counts when 25% of the MIC of each antibiotic was used. These results indicate that infections due to resistant Pseudomonas strains could be treated by the use of a synergistic combination of PEI and antimicrobial drugs.Over the past two decades, Pseudomonas aeruginosa has attracted attention as an opportunistic pathogen in hospitalized, immunocompromised, and cystic fibrosis patients (6,15,20). Despite aggressive antibiotic therapy, P. aeruginosa is rarely eradicated owing to its high level of intrinsic resistance to many drugs (14,19,27). This resistance is due to the effective permeability of the outer membrane (OM) of gram-negative bacteria to both hydrophobic antibiotics and high-molecular-weight hydrophilic drugs (for reviews, see references 4, 25, 28, and 30). Unlike most cell types, gram-negative bacteria surround themselves with a double membrane. The outermost of these two membranes is asymmetric, with the inner leaflet composed of glycerophospholipids and the outer leaflet predominantly composed of lipopolysaccharide (LPS). Tight interactions between the highly negatively charged LPS molecules are believed to form an effective barrier against hydrophobic compounds. For these polyanionic molecules to form a stable "tiled roof" on the surface of the OM, adjacent LPS molecules are linked electrostatically by divalent cations (Ca 2ϩ , Mg 2ϩ ) present in the OM. Polyethylenimine (PEI) is a weakly basic, aliphatic, nontoxic synthetic polymer which is polycationic owing to the presence of primary, secondary, and tertiary amino groups. It is well known that certain polycationic agents such as polymyxin and its derivatives polylysines and protamine can increase the permeability of the gram-negative bacterial OM to solutes that are normally unable to penetrate (25). Helander et al. found that, when it was applied alone, PEI has a strong permeabilizing effect but no bactericidal effect on gram-negative bacteria (8). Escherichia coli, P. aeruginosa, and Salmon...

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Enhancement by cationic compounds of the growth inhibitory effect of novobiocin on Escherichia coli

Cited by 8 publications

References 9 publications

Comparative analysis of selected methods for the assessment of antimicrobial and membrane-permeabilizing activity: a case study for lactoferricin derived peptides

Comparative analysis of selected methods for the assessment of antimicrobial and membrane-permeabilizing activity: a case study for lactoferricin derived peptides

Effect of permeabilizers on antibiotic sensitivity ofPseudomonas aeruginosa

Synergy between Polyethylenimine and Different Families of Antibiotics against a Resistant Clinical Isolate of Pseudomonas aeruginosa

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