Interventions on Metabolism: Making Antibiotic-Susceptible Bacteria

Baquero, Fernando; Martínez, José Luis

doi:10.1128/mbio.01950-17

Cited by 22 publications

(22 citation statements)

References 10 publications

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“…The threat of extensively drug-resistant S. Typhi isolates requires the development of new treatment strategies. One approach is the search for antibiotics adjuvants-compounds (Murima et al, 2014;Baquero and Martínez, 2017). In a non-exhaustive screening of S. Typhi STH2370, we found the mutant S. Typhi glnA::EZ-Tn5, with half the MIC to CIP.…”

Section: Discussionmentioning

confidence: 99%

“…This change reveals a low-level resistance, mediated by an intrinsic mechanism of protection in a microorganism that is in principle susceptible to CIP. It is thought that the genes determining such intrinsic lowlevels of resistance (2-to 4-times the MIC) might be of clinical importance and they could be target for adjuvant therapies (Baquero and Martínez, 2017). GS plays a crucial role in nitrogen metabolism whose main function is to provide glutamine to the cell.…”

Section: Discussionmentioning

confidence: 99%

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Inactivation of Glutamine Synthetase-Coding Gene glnA Increases Susceptibility to Quinolones Through Increasing Outer Membrane Protein F in Salmonella enterica Serovar Typhi

et al. 2020

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Ciprofloxacin is the choice treatment for infections caused by Salmonella Typhi, however, reduced susceptibility to ciprofloxacin has been reported for this pathogen. Considering the decreased approbation of new antimicrobials and the crisis of resistance, one strategy to combat this problem is to find new targets that enhances the antimicrobial activity for approved antimicrobials. In search of mutants with increased susceptibility to ciprofloxacin; 3,216 EZ-Tn5 transposon mutants of S. Typhi were screened. S. Typhi zxx::EZ-Tn5 mutants susceptible to ciprofloxacin were confirmed by agar diffusion and MIC assays. The genes carrying EZ-Tn5 transposon insertions were sequenced. Null mutants of interrupted genes, as well as inducible genetic constructs, were produced using site-directed mutagenesis, to corroborate phenotypes. SDS-PAGE and Real-time PCR were used to evaluate the expression of proteins and genes, respectively. Five mutants with increased ciprofloxacin susceptibility were found in the screening. The first confirmed mutant was the glutamine synthetase-coding gene glnA. Analysis of outer membrane proteins revealed increased OmpF, a channel for the influx of ciprofloxacin and nalidixic acid, in the glnA mutant. Expression of ompF increased four times in the glnA null mutant compared to WT strain. To understand the relationship between the expression of glnA and ompF, a strain with the glnA gene under control of the tetracycline-inducible P tet promoter was created, to modulate glnA expression. Induction of glnA decreased expression of ompF, at the same time that reduced susceptibility to ciprofloxacin. Expression of sRNA MicF, a negative regulator of OmpF was reduced to one-fourth in the glnA mutant, compared to WT strain. In addition, expression of glnL and glnG genes (encoding the two-component system NtrC/B that may positively regulate OmpF) were increased in the glnA mutant. Further Frontiers in Microbiology | www.frontiersin.org 1 March 2020 | Volume 11 | Article 428Millanao et al.glnA Inactivation Increases Quinolones Susceptibility studies indicate that deletion of glnG decreases susceptibility to CIP, while deletion of micF gene increases susceptibility CIP. Our findings indicate that glnA inactivation promotes ompF expression, that translates into increased OmpF protein, facilitating the entry of ciprofloxacin, thus increasing susceptibility to ciprofloxacin through 2 possible mechanisms.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Inactivation of Glutamine Synthetase-Coding Gene glnA Increases Susceptibility to Quinolones Through Increasing Outer Membrane Protein F in Salmonella enterica Serovar Typhi

et al. 2020

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“…This example illustrates the hypothesis that a higher prevalence of resistance in the E. coli component of the gut flora might reduce the frequency of other resistant organisms, which might inspire interventions directed to restore susceptibility in particular species (10,11).…”

Section: Influence Of Baseline Resistance Composition On the Dynamicsmentioning

confidence: 87%

Simulating multi-level dynamics of antimicrobial resistance in a membrane computing model

Campos

Capilla

Lloréns

et al. 2018

Preprint

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Membrane Computing is a bio-inspired computing paradigm, whose devices are the socalled membrane systems or P systems. The P system designed in this work reproduces complex biological landscapes in the computer world. It uses nested "membranesurrounded entities" able to divide, propagate and die, be transferred into other membranes, exchange informative material according to flexible rules, mutate and being selected by external agents. This allows the exploration of hierarchical interactive dynamics resulting from the probabilistic interaction of genes (phenotypes), clones, species, hosts, environments, and antibiotic challenges. Our model facilitates analysis of several aspects of the rules that govern the multi-level evolutionary biology of antibiotic resistance. We examine a number of selected landscapes where we predict the effects of different rates of patient flow from hospital to the community and viceversa, crosstransmission rates between patients with bacterial propagules of different sizes, the proportion of patients treated with antibiotics, antibiotics and dosing in opening spaces in the microbiota where resistant phenotypes multiply. We can also evaluate the selective strength of some drugs and the influence of the time-0 resistance composition of the species and bacterial clones in the evolution of resistance phenotypes. In summary, we provide case studies analyzing the hierarchical dynamics of antibiotic resistance using a novel computing model with reciprocity within and between levels of biological organization, a type of approach that may be expanded in the multi-level analysis of complex microbial landscapes.

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“…Previous analysis has shown that E. coli mutants deficient in the metabolic enzyme isocitrate dehydrogenase are resistant to nalidixic acid (35). However, little work is still available in the crosstalk between metabolism (and metabolic robustness) and antibiotic resistance (57, 58), despite the fact that metabolic interventions may improve the activity of the antibiotics (33, 59-61) and that bacterial metabolism can constrain the evolution of antibiotic resistance (13). Our results highlight the importance that the modification of the activity of enzymes belonging to central metabolism may have in the susceptibility to antibiotics, as fosfomycin, that are not known to interact with such enzymes.…”

Section: Discussionmentioning

confidence: 99%

“…In this bacterial species, fosfomycin resistance was acquired due to mutations in genes encoding enzymes of the Embden-Meyerhof-Parnas (EMP) metabolic pathway. It has been suggested that antibiotic resistance can be inter-linked to bacterial metabolism (33, 34). However, with very few exceptions (35), the mutational inactivation of genes encoding enzymes of the central carbon metabolism has not been considered to be a significant cause of antibiotic resistance in bacterial pathogens (34, 35).…”

Section: Introductionmentioning

confidence: 99%

The inactivation of enzymes belonging to the central carbon metabolism, a novel mechanism of developing antibiotic resistance

Gil-Gil

Corona

Martínez

et al. 2019

Preprint

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Fosfomycin is a bactericidal antibiotic, analogous to phosphoenolpyruvate (PEP) that exerts its activity by inhibiting the activity of MurA. This enzyme catalyzes the first step of peptidoglycan biosynthesis, the transfer of enolpyruvate from PEP to uridine-diphosphate-N-acetylglucosamine. Fosfomycin is increasingly used in the last years, mainly for treating infections caused by Gram-negative multidrug resistant bacteria as Stenotrophomonas maltophilia, an opportunistic pathogen characterized by its low susceptibility to antibiotics of common use. The mechanisms of mutational resistance to fosfomycin in S. maltophilia were studied in the current work. None of the mechanisms so far described for other organisms, which include the production of fosfomycin inactivating enzymes, target modification, induction of alternative peptidoglycan biosynthesis pathway and the impaired entrance of the antibiotic, are involved in the acquisition of such resistance by this bacterial species. Rather the unique cause of resistance in the studied mutants is the mutational inactivation of different enzymes belonging to the Embden-Meyerhof-Parnas central metabolism pathway. The amount of intracellular fosfomycin accumulation did not change in any of these mutants showing that neither the inactivation nor the transport of the antibiotic were involved. Transcriptomic analysis also showed that the mutants did not present changes in the expression level of putative alternative peptidoglycan biosynthesis pathway genes neither any related enzyme. Finally, the mutants did not present an increased PEP concentration that might compete with fosfomycin for its binding to MurA. Based on these results, we describe a completely novel mechanism of antibiotic resistance based on the remodeling of S. maltophilia metabolism.SignificanceAntibiotic resistance (AR) has been largely considered as a specific bacterial response to an antibiotic challenge. Indeed, its study has been mainly concentrated in mechanisms that affect the antibiotics (mutations in transporters, the activity of efflux pumps and antibiotic modifying enzymes) or their targets (i.e.: target mutations, protection or bypass). Usually, AR-associated metabolic changes were considered to be a consequence (fitness costs) and not a cause of AR. Herein, we show that strong alterations in the bacterial metabolism can also be the cause of AR. In the study here presented, Stenotrophomonas maltophilia acquires fosfomycin resistance through the inactivation of glycolytic enzymes belonging to the Embden-Meyerhof-Parnas. Besides resistance to fosfomycin, this inactivation also impairs the bacterial gluconeogenic pathway. Together with previous work showing that AR can be under metabolic control, our results provide evidence that AR is intertwined with the bacterial metabolism.

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Interventions on Metabolism: Making Antibiotic-Susceptible Bacteria

Cited by 22 publications

References 10 publications

Inactivation of Glutamine Synthetase-Coding Gene glnA Increases Susceptibility to Quinolones Through Increasing Outer Membrane Protein F in Salmonella enterica Serovar Typhi

Inactivation of Glutamine Synthetase-Coding Gene glnA Increases Susceptibility to Quinolones Through Increasing Outer Membrane Protein F in Salmonella enterica Serovar Typhi

Simulating multi-level dynamics of antimicrobial resistance in a membrane computing model

The inactivation of enzymes belonging to the central carbon metabolism, a novel mechanism of developing antibiotic resistance

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