-
Science (New York, N.Y.) Feb 2021Although metabolism plays an active role in antibiotic lethality, antibiotic resistance is generally associated with drug target modification, enzymatic inactivation,...
Although metabolism plays an active role in antibiotic lethality, antibiotic resistance is generally associated with drug target modification, enzymatic inactivation, and/or transport rather than metabolic processes. Evolution experiments of rely on growth-dependent selection, which may provide a limited view of the antibiotic resistance landscape. We sequenced and analyzed adapted to representative antibiotics at increasingly heightened metabolic states. This revealed various underappreciated noncanonical genes, such as those related to central carbon and energy metabolism, which are implicated in antibiotic resistance. These metabolic alterations lead to lower basal respiration, which prevents antibiotic-mediated induction of tricarboxylic acid cycle activity, thus avoiding metabolic toxicity and minimizing drug lethality. Several of the identified metabolism-specific mutations are overrepresented in the genomes of >3500 clinical pathogens, indicating clinical relevance.
Topics: Adaptation, Physiological; Anti-Bacterial Agents; Carbenicillin; Ciprofloxacin; Citric Acid Cycle; Directed Molecular Evolution; Drug Resistance, Bacterial; Energy Metabolism; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Gene Knockdown Techniques; Genes, Bacterial; Genome, Bacterial; Ketoglutarate Dehydrogenase Complex; Microbial Sensitivity Tests; Mutation; Sequence Analysis, DNA; Streptomycin
PubMed: 33602825
DOI: 10.1126/science.aba0862 -
British Medical Journal Dec 1970
Topics: Adult; Aged; Female; Humans; Hypokalemia; Penicillins; Pseudomonas Infections
PubMed: 5491267
DOI: 10.1136/bmj.4.5737.746 -
Antibiotics (Basel, Switzerland) May 2022The biological effects of alkaloids, curine, guattegaumerine, and verapamil, on were investigated. These molecules did not inhibit growth but increased the sensitivity...
The biological effects of alkaloids, curine, guattegaumerine, and verapamil, on were investigated. These molecules did not inhibit growth but increased the sensitivity of this bacterium to carbenicillin, novobiocin, and erythromycin. The results of another study indicate that curine and guattegaumerine were competitors of verapamil and acted as inhibitors of eukaryotic ABCB1 efflux pump. A BLAST-P carried out between a bacterial MDR transporter LmrA from , a human MDR1/P-glycoprotein (ABCB1), and ABC proteins of highlighted five potential candidates that have this bacterium. A study on the sensitivity to carbenicillin in the presence of verapamil allowed us to identify the product of gene PA1113 as the ABC transporter involved in the influx of carbenicillin. Similarly, novobiocin transport performed in the presence of verapamil and a docking analysis highlighted protein MsbA (Lipid A flippase, gene PA4997) as a potential candidate in novobiocin efflux. MsbA has previously been identified as a multidrug transporter in , and as MsbA presented 76% identity with MsbA, it is possible that novobiocin efflux involves this ABC transporter, accounting for about 30% of the bacterium resistance to this antibiotic.
PubMed: 35625344
DOI: 10.3390/antibiotics11050700 -
Nature Communications Feb 2023Antibiotics are a key control mechanism for synthetic biology and microbiology. Resistance genes are used to select desired cells and regulate bacterial populations,...
Antibiotics are a key control mechanism for synthetic biology and microbiology. Resistance genes are used to select desired cells and regulate bacterial populations, however their use to-date has been largely static. Precise spatiotemporal control of antibiotic resistance could enable a wide variety of applications that require dynamic control of susceptibility and survival. Here, we use light-inducible Cre recombinase to activate expression of drug resistance genes in Escherichia coli. We demonstrate light-activated resistance to four antibiotics: carbenicillin, kanamycin, chloramphenicol, and tetracycline. Cells exposed to blue light survive in the presence of lethal antibiotic concentrations, while those kept in the dark do not. To optimize resistance induction, we vary promoter, ribosome binding site, and enzyme variant strength using chromosome and plasmid-based constructs. We then link inducible resistance to expression of a heterologous fatty acid enzyme to increase production of octanoic acid. These optogenetic resistance tools pave the way for spatiotemporal control of cell survival.
Topics: Optogenetics; Anti-Bacterial Agents; Drug Resistance, Microbial; Tetracycline; Carbenicillin; Escherichia coli
PubMed: 36823420
DOI: 10.1038/s41467-023-36670-2 -
Antimicrobial Agents and Chemotherapy Feb 1978Mezlocillin is a new broad-spectrum semisynthetic penicillin that has shown encouraging in vitro activity against the infecting organisms most likely to cause mortality...
Mezlocillin is a new broad-spectrum semisynthetic penicillin that has shown encouraging in vitro activity against the infecting organisms most likely to cause mortality and morbidity in cancer patients receiving chemotherapy. The serum clearances and urine recoveries of mezlocillin, ampicillin, and carbenicillin were compared after the intravenous administration of single 3-g doses. The peak mean serum concentrations of mezlocillin and carbenicillin were 269 and 278 mug/ml, respectively, whereas the peak ampicillin level was lower at 167 mug/ml. The terminal half-life of mezlocillin, 66 min, was not significantly different from those of ampicillin and carbencillin (63 and 77 min, respectively). Recoveries of mezlocillin, ampicillin, and carbenicillin from urine over 6-h periods after drug dosage were 45, 61, and 80%, respectively. A further study in 11 cancer patients examined serum maintenance levels of mezlocillin when 3-g doses were given intravenously every 4 h for at least 7 consecutive days. After 3 days of therapy, the mean serum concentrations were maintained above 50 mug/ml. Although therapeutic efficacy was not an objective of this study, all of three documented bacterial infections were cured, and no serious toxicity was encountered.
Topics: Adolescent; Adult; Aged; Bacterial Infections; Female; Half-Life; Humans; Male; Middle Aged; Neoplasms; Penicillins; Time Factors
PubMed: 646340
DOI: 10.1128/AAC.13.2.180 -
The Journal of Antibiotics May 1979The synthesis of a new penicillin, disodium D-6-[alpha-(1,2,4-triazine-3,5-dione-6-carboxyamido)-4-hydroxyphenylacetamido]penicillanate (BL-P1908), is described. The... (Comparative Study)
Comparative Study
The synthesis of a new penicillin, disodium D-6-[alpha-(1,2,4-triazine-3,5-dione-6-carboxyamido)-4-hydroxyphenylacetamido]penicillanate (BL-P1908), is described. The compound shows superior in vitro activity against Pseudomonas aeruginosa compared to carbenicillin and ticarcillin and produces higher intramuscular serum levels in mice than does carbenicillin.
Topics: Animals; Chemical Phenomena; Chemistry; Chemistry, Physical; Mice; Penicillin Resistance; Penicillins; Pseudomonas aeruginosa
PubMed: 118961
DOI: 10.7164/antibiotics.32.468 -
Antimicrobial Agents and Chemotherapy Feb 1978The in vitro activities of ticarcillin (T) and carbenicillin (C) against 253 strains of Pseudomonas aeruginosa (108 randomly selected clinical isolates and 145 isolates... (Clinical Trial)
Clinical Trial Comparative Study
The in vitro activities of ticarcillin (T) and carbenicillin (C) against 253 strains of Pseudomonas aeruginosa (108 randomly selected clinical isolates and 145 isolates determined to be C resistant by 10 referring hospitals) were evaluated using both broth microdilution and disk diffusion techniques. T activity was usually twofold or greater than C activity for individual strains in both sample populations. The minimal inhibitory concentration (MIC) values of T and C were =0.4 to >400 (median, 25) and 0.8 to >400 (median, 50) mug/ml, respectively, for the random sample and 1.6 to >400 (median, 50) and 12.5 to >400 (median, 200) mug/ml, respectively, for the select sample. For predicting susceptibility (MIC, =50 mug of T and =100 mug of C per ml), 75-mug T and 100-mug C disks were equivalent in accuracy for the random sample (T/T = 92.6%, T/C = 92.0%, C/T = 91.7%, C/C = 89.8%). Regression-line analyses of zones of inhibition versus MIC values for the four combinations showed coefficients of correlation to be -0.81, -0.76, -0.77, and -0.75, respectively. With the sample selected as being resistant to C, T was better than C for predicting T susceptibility (P < 0.05), and T was equivalent to C for predicting C susceptibility (T/T = 84.3%, T/C = 81.0%, C/T = 73.6%, C/C = 80.4%). Coefficients of correlation were -0.70, -0.74, -0.55, and -0.61, respectively. T and C disks were, therefore, equivalent for determining T and C susceptibilities, but the T disk was more reliable for determining T susceptibility in a population skewed with C-resistant strains.
Topics: Carbenicillin; Microbial Sensitivity Tests; Penicillins; Pseudomonas aeruginosa; Ticarcillin
PubMed: 417671
DOI: 10.1128/AAC.13.2.184 -
Microbiological Research Sep 2019Functional association between genomic loci and specific biological traits remains lacking in many fungi, including the African tree pathogen Ceratocystis albifundus....
Functional association between genomic loci and specific biological traits remains lacking in many fungi, including the African tree pathogen Ceratocystis albifundus. This is mainly because of the absence of suitable transformation systems for allowing genetic manipulation of this and other fungi. Here, we present an optimized protocol for Agrobacterium tumefaciens-mediated transformation of C. albifundus. Strain AGL-1 of A. tumefaciens and four binary T-DNA vectors (conferring hygromycin B or geneticin resistance and/or expressing the green fluorescent protein [GFP]) were used for transforming germinated conidia of three isolates of C. albifundus. Stable expression of these T-DNA-encoded traits was confirmed through sequential sub-culturing of fungal transformants on selective and non-selective media and by using PCR and sequence analysis. Single-copy integration of the respective T-DNAs into the genomes of these fungi was confirmed using Southern hybridization analysis. The range of experimental parameters determined and optimised included: (i) concentrations of hygromycin B and geneticin required for inhibiting growth of the wild type fungus and (ii) the dependence of transformation on acetosyringone for inducing the bacterium's virulence genes, as well as (iii) the duration of fungus-bacterium co-cultivation periods and (iv) the concentrations of fungal conidia and bacterial cells used for the latter. The system developed in this study is stable with a high-efficiency, yielding up to 400 transformants per 10 conidia. This is the first report of a transformation protocol for C. albifundus and its availability will be invaluable for functional studies in this important fungus.
Topics: Agrobacterium tumefaciens; Ascomycota; Blotting, Southern; Carbenicillin; Coculture Techniques; DNA, Bacterial; Gene Expression Regulation, Fungal; Gentamicins; Green Fluorescent Proteins; Hygromycin B; Kanamycin; Polymerase Chain Reaction; Sequence Analysis; Transformation, Genetic; Virulence
PubMed: 31284945
DOI: 10.1016/j.micres.2019.05.004