Ampicillin-Resistant Mutants of<i>Escherichia coli</i>K-12 with Lipopolysaccharide Alterations Affecting Mating Ability and Susceptibility to Sex-Specific Bacteriophages

Monner, David A.; Jonsson, Staffan; Boman, Hans G.

doi:10.1128/jb.107.2.420-432.1971

Cited by 104 publications

(66 citation statements)

References 36 publications

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“…The test strain used was Dl 1, an E. coli K12 strain which is wild-type in its sensitivity to penicillin-related antibiotics and has the following genotype: F-trp pro his strA tsx (Monner et al, 1971).…”

Section: Methodsmentioning

confidence: 99%

The antibacterial effect of attacins from the silk moth Hyalophora cecropia is directed against the outer membrane of Escherichia coli.

Engström¹,

Carlsson²,

Engström³

et al. 1984

The EMBO Journal

107

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The attacins are antibacterial proteins which accumulate in the hemolymph of the giant silk moth, Hyalophora cecropia, in response to a bacterial infection. Here we show that the permeability barrier function of the outer membrane is affected shortly after addition of attacin to growing cultures of Escherichia coli. Specifically, the penetration through the outer membrane of beta‐lactam antibiotics, chicken egg white lysozyme and the detergent Triton X‐100 was found to be facilitated. The sensitivity of E. coli to cecropin B, another antibacterial protein present in the hemolymph of H. cecropia, was also found to be increased after treatment with attacin. The results suggest that the target of the attacins in E. coli is the outer membrane. Other effects of the attacins which have been observed are likely to be indirect consequences of the alteration in the properties of the outer membrane. These effects include changes in the cell shape, irregular patterns of cell division and lysis. The minimal concentration at which the attacins affected the growth of E. coli was 1 and 0.5 microM for the neutral (pI 7) and basic (pI 9) attacins, respectively, which corresponds to less than 2% of the concentration of the attacins in the hemolymph of infected pupae.

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Section: Methodsmentioning

confidence: 99%

The antibacterial effect of attacins from the silk moth Hyalophora cecropia is directed against the outer membrane of Escherichia coli.

Engström¹,

Carlsson²,

Engström³

et al. 1984

The EMBO Journal

107

View full text Add to dashboard Cite

show abstract

“…Measurement of antimicrobial activity of the mucus was based upon a turbidimetric assay from Noga et al (1994), where inhibition of Escherichia coli D31 (E. coli D31: Monner et al, 1971) treated with plasma was measured after 36 h of incubation. Vibrio anguillarum and Vibrio parahaemolyticus were obtained from the culture collection at Yale University.…”

Section: A N T I M I C Ro B I a L A S S Aymentioning

confidence: 99%

Measures of immune system status in young‐of‐the‐year winter flounderPseudopleuronectes americanus

Romany

McElroy

Fast

2015

Journal of Fish Biology

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The immune status of young-of-the-year (YOY) winter flounder Pseudopleuronectes americanus was evaluated in fish collected from six areas around Long Island, NY, U.S.A. representing more urban areas with high population density in the west, to less densely populated more rural areas in to the east. Gene expression markers for innate immunity (pleurocidin) and contaminant exposure (cytochrome P4501A; cyp1a) were measured in liver and fin of fish collected at each site. Expression of pleurocidin was significantly higher in fin than liver, but was highly variable among individuals. Some statistically significant differences in pleurocidin expression among sites were observed, although elevated levels were not associated with degree of urbanization. Expression was related in part to fish size: a positive correlation between expression and total length (LT ) of fish was observed with the largest LT class (>125 mm) exhibiting significantly elevated pleurocidin expression as compared with fish in the smaller LT class. This indicates that immune competency may increase with age. No site-specific differences in cyp1a expression were observed. These data suggest that exposure to aromatic hydrocarbon contaminants is fairly widespread throughout the study area and that any differences in pleurocidin expression in YOY P. americanus are probably due to other factors. Antimicrobial activity was also measured as a functional indicator of immune response. Activity was highly variable, showing no significant site-specific differences, and no significant correlation to pleurocidin expression. The lack of correlation between pleurocidin expression and antimicrobial activity indicates that other antimicrobial peptides may be active against the bacteria tested or that other factors are influencing antimicrobial activity. This is the first quantitative evaluation of pleurocidin expression in YOY P. americanus from an urban area. Further work is needed to characterize factors controlling pleurocidin expression, as well as other indicators of immune response in young fish.

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“…D21 parental strains and derivative mutants were obtained from the E. coli Genetic Stock Center (cgsc.biology.yale.edu/top.html). These strains have been characterised and their LPS composition deduced after gas chromatography analysis of carbohydrates [15][16][17][18]. Lipid A mutant strains MLK43, 986 and 1067 were kindly donated by Professor C.R.…”

Section: Bacterial Strainsmentioning

confidence: 99%

Interactions of lactoferricin-derived peptides with LPS and antimicrobial activity

Farnaud¹

2004

FEMS Microbiology Letters

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Synthetic peptides derived from human and bovine lactoferricin, as well as tritrpticin sequences, were assayed for antimicrobial activity against wild-type Escherichia coli and LPS mutant strains. Antimicrobial activity was only obtained with peptides derived from the bovine lactoferricin sequence and peptides corresponding to chimeras of human and bovine sequences. None of the peptides corresponding to different regions of native human lactoferricin showed any antimicrobial activity. The results underline the importance of the content of tryptophan and arginine residues, and the relative location of these residues for antimicrobial activity. Results obtained for the same assays performed with LPS mutants suggest that lipid A is not the main binding site for lactoferricin which interacts first with the negative charges present in the inner core. Computer modelling of the most active peptides led to a model in which positively charged residues of the cationic peptide interact with negative charges carried by the LPS to disorganise the structure of the outer membrane and facilitate the approach of tryptophan residues to the lipid A in order to promote hydrophobic interactions.

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Ampicillin-Resistant Mutants ofEscherichia coliK-12 with Lipopolysaccharide Alterations Affecting Mating Ability and Susceptibility to Sex-Specific Bacteriophages

Cited by 104 publications

References 36 publications

The antibacterial effect of attacins from the silk moth Hyalophora cecropia is directed against the outer membrane of Escherichia coli.

The antibacterial effect of attacins from the silk moth Hyalophora cecropia is directed against the outer membrane of Escherichia coli.

Measures of immune system status in young‐of‐the‐year winter flounderPseudopleuronectes americanus

Interactions of lactoferricin-derived peptides with LPS and antimicrobial activity

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