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

2019 ◽  
Author(s):  
Teresa Gil-Gil ◽  
Fernando Corona ◽  
José Luis Martínez ◽  
Alejandra Bernardini
Keyword(s):  
Antibiotic Resistance ◽  
Stenotrophomonas Maltophilia ◽  
Bacterial Species ◽  
Opportunistic Pathogen ◽  
Central Carbon Metabolism ◽  
Bacterial Metabolism ◽  
Resistant Bacteria ◽  
Uridine Diphosphate ◽  
Biosynthesis Pathway ◽  
Peptidoglycan Biosynthesis

AbstractFosfomycin 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.

scholarly journals The Inactivation of Enzymes Belonging to the Central Carbon Metabolism Is a Novel Mechanism of Developing Antibiotic Resistance

mSystems ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Teresa Gil-Gil ◽  
Fernando Corona ◽  
José Luis Martínez ◽  
Alejandra Bernardini
Keyword(s):  
Antibiotic Resistance ◽  
Stenotrophomonas Maltophilia ◽  
Bacterial Species ◽  
Bacterial Metabolism ◽  
Resistant Bacteria ◽  
Uridine Diphosphate ◽  
Biosynthesis Pathway ◽  
Content Type ◽  
Peptidoglycan Biosynthesis ◽  
Central Carbon

ABSTRACT Fosfomycin is a bactericidal antibiotic, analogous to phosphoenolpyruvate, that exerts its activity by inhibiting the activity of MurA. This enzyme catalyzes the first step of peptidoglycan biosynthesis, the transfer of enolpyruvate from phosphoenolpyruvate to uridine-diphosphate-N-acetylglucosamine. Fosfomycin is increasingly being used, mainly for treating infections caused by Gram-negative multidrug-resistant bacteria. The mechanisms of mutational resistance to fosfomycin in Stenotrophomonas maltophilia, an opportunistic pathogen characterized by its low susceptibility to commonly used antibiotics, were studied in the current work. None of the mechanisms reported so far for other organisms, which include the production of fosfomycin-inactivating enzymes, target modification, induction of an alternative peptidoglycan biosynthesis pathway, and the impaired entry of the antibiotic, are involved in the acquisition of such resistance by this bacterial species. Instead, the unique cause of resistance in the mutants studied 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 inactivation nor transport of the antibiotic is involved. Transcriptomic analysis also showed that the mutants did not present changes in the expression level of putative alternative peptidoglycan biosynthesis pathway genes or any related enzyme. Finally, the mutants did not present an increased phosphoenolpyruvate concentration that might compete with fosfomycin for its binding to MurA. On the basis of these results, we describe a completely novel mechanism of antibiotic resistance based on mutations of genes encoding metabolic enzymes. IMPORTANCE Antibiotic resistance has been largely considered a specific bacterial response to an antibiotic challenge. Indeed, its study has been mainly concentrated on mechanisms that affect the antibiotics (mutations in transporters, efflux pumps, and antibiotic-modifying enzymes, or their regulators) or their targets (i.e., target mutations, protection, or bypass). Usually, antibiotic resistance-associated metabolic changes were considered a consequence (fitness costs) and not a cause of antibiotic resistance. Herein, we show that alterations in the central carbon bacterial metabolism can also be the cause of antibiotic resistance. In the study presented here, Stenotrophomonas maltophilia acquires fosfomycin resistance through the inactivation of glycolytic enzymes belonging to the Embden-Meyerhof-Parnas pathway. Besides resistance to fosfomycin, this inactivation also impairs the bacterial gluconeogenic pathway. Together with previous work showing that antibiotic resistance can be under metabolic control, our results provide evidence that antibiotic resistance is intertwined with the bacterial metabolism.

scholarly journals Antimicrobial Resistance among Neonates with Bacterial Sepsis and Their Clinical Outcomes in a Tertiary Hospital in Kathmandu Valley, Nepal

2021 ◽  
Vol 6 (2) ◽  
pp. 56
Author(s):  
Bijendra Raj Raghubanshi ◽  
Karuna D. Sagili ◽  
Wai Wai Han ◽  
Henish Shakya ◽  
Priyanka Shrestha ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Neonatal Sepsis ◽  
Bacterial Culture ◽  
Bacterial Species ◽  
Antibiotic Sensitivity ◽  
College Teaching ◽  
Hospital Treatment ◽  
Resistant Bacteria ◽  
Coagulase Negative Staphylococcus ◽  
Cross Sectional

Globally, antibiotic resistance in bacteria isolated from neonatal sepsis is increasing. In this cross-sectional study conducted at a medical college teaching hospital in Nepal, we assessed the antibiotic resistance levels in bacteria cultured from neonates with sepsis and their in-hospital treatment outcomes. We extracted data of neonates with sepsis admitted for in-patient care from June 2018 to December 2019 by reviewing hospital records of the neonatal intensive care unit and microbiology department. A total of 308 neonates with sepsis were admitted of which, blood bacterial culture antibiotic sensitivity reports were available for 298 neonates. Twenty neonates (7%) had bacteriologic culture-confirmed neonatal sepsis. The most common bacterial species isolated were Staphylococcus aureus (8), followed by coagulase-negative Staphylococcus (5). Most of these bacteria were resistant to at least one first-line antibiotic used to manage neonatal sepsis. Overall, there were 7 (2%) deaths among the 308 neonates (none of them from the bacterial culture-positive group), and 53 (17%) neonates had left the hospital against medical advice (LAMA). Improving hospital procedures to isolate bacteria in neonates with sepsis, undertaking measures to prevent the spread of antibiotic-resistant bacteria, and addressing LAMA’s reasons are urgently needed.

scholarly journals The antibiotic resistance of heterotrophic bacteria in tap waters in London

2018 ◽  
Vol 19 (1) ◽  
pp. 179-190
Author(s):  
R. Destiani ◽  
M. R. Templeton
Keyword(s):  
Antibiotic Resistance ◽  
Stenotrophomonas Maltophilia ◽  
Heterotrophic Bacteria ◽  
Tap Water ◽  
Antibiotic Resistance Genes ◽  
Resistant Bacteria ◽  
Opportunistic Pathogens ◽  
Antibiotic Resistant ◽  
Sampling Locations ◽  
The City

Abstract This study assessed the occurrence and prevalence of antibiotic-resistant bacteria (ARBs) and antibiotic resistance genes (ARGs) in tap water sampled across London, United Kingdom. Sampling was conducted seasonally from nine locations spread geographically across the city. ARBs and ARGs (tet(A), dfrA7, and sul1) were detected in all sampling locations in all sampling rounds. Resistance to trimethoprim was the highest among the tested antibiotics and the sul1 gene was the most abundant resistance gene detected. Several opportunistic pathogens were identified amongst the ARBs in the water samples, including Pseudomonas aeruginosa and Stenotrophomonas maltophilia.

scholarly journals Interventions on Metabolism: Making Antibiotic-Susceptible Bacteria

mBio ◽  
2017 ◽  
Vol 8 (6) ◽  
Author(s):  
Fernando Baquero ◽  
José-Luis Martínez
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Recent Article ◽  
Transcriptional Regulators ◽  
Drug Susceptibility ◽  
Bacterial Metabolism ◽  
Metabolic Enzyme ◽  
Resistant Bacteria ◽  
Metabolic Genes ◽  
Drug Interventions

ABSTRACT Antibiotics act on bacterial metabolism, and antibiotic resistance involves changes in this metabolism. Interventions on metabolism with drugs might therefore modify drug susceptibility and drug resistance. In their recent article, Martin Vestergaard et al. (mBio 8:e01114-17, 2017, https://doi.org/10.1128/mBio.01114-17 !) illustrate the possibility of converting intrinsically resistant bacteria into susceptible ones. They reported that inhibition of a central metabolic enzyme, ATP synthase, allows otherwise ineffective polymyxin antibiotics to act on Staphylococcus aureus. The study of the intrinsic resistome of bacterial pathogens has shown that several metabolic genes, including multigene transcriptional regulators, contribute to antibiotic resistance. In some cases, these genes only marginally increase antibiotic resistance, but reduced levels of susceptibility might be critical in the evolution or resistance under low antibiotic concentrations or in the clinical response of highly resistant bacteria. Drug interventions on bacterial metabolism might constitute a critical adjuvant therapy in combination with antibiotics to ensure susceptibility of pathogens with intrinsic or acquired antimicrobial resistance.

scholarly journals A Microbiome-Based Solution to Address Alarming Levels of Drug-Resistant Bacteria in the Newborn Infant Gut

2020 ◽  
Vol 41 (S1) ◽  
pp. s439-s439
Author(s):  
Giorgio Casaburi ◽  
Rebbeca Duar ◽  
Bethany Henrick ◽  
Steven Frese
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Bacterial Species ◽  
The United States ◽  
Resistant Bacteria ◽  
Delivery Mode ◽  
Term Infants ◽  
Shotgun Metagenomics ◽  
Single Strain ◽  
Breastfed Infants

Background: Recent studies have focused on the early infant gut microbiome, indicating that antibiotic resistance genes (ARGs) can be acquired in early life and may have long-term sequelae. Limiting the spread of antimicrobial resistance without triggering the development of additional resistance mechanisms would be of immense clinical value. Here, we present 2 analyses that highlight the abundance of ARGs in preterm and term infants and a proof of concept for modulating the microbiome to promote early stabilization and reduction in ARGs in term infants. Methods: Large-scale metagenomic analysis was performed on 2,141 microbiome samples (90% from pre-term infants) from 10 countries; most were from the United States (87%) and were obtained from the Comprehensive Antibiotic Resistance Database (CARD). We assessed the abundance and specific types of ARGs present. In the second study, healthy, breastfed infants were fed B. infantis EVC001 for 3 weeks starting at postnatal day 7. Stool samples were collected at day 21 and were processed utilizing shotgun metagenomics. Selected antimicrobial-resistant bacterial species were isolated, sequenced, and tested for minimal inhibitory concentrations to clinically relevant antibiotics. Results: In the first study, globally, 417 distinct ARGs were identified. The most abundant gene among all samples was annotated as msrE, a plasmid gene known to confer resistance to macrolide-lincosamide-streptogramin B (MLSB) antibiotics. The remaining most-abundant ARGs were efflux-pump genes associated with multidrug resistance. No significant association in antimicrobial resistance was found when considering delivery mode or antibiotic treatment in the first month of life. In the second study, the EVC001-fed group showed a significant decrease (90%) in ARGs compared to controls (P < .0001). ARGs that differed significantly between groups were predicted to confer resistance to β-lactams, fluoroquinolones, or multiple drug classes. Minimal inhibitory concentration assays confirmed resistance phenotypes among isolates Notably, we found resistance to extended-spectrum β-lactamases among healthy, vaginally delivered breastfed infants who had never been exposed to antibiotics. Conclusions: In this study, we show that the term and preterm infant microbiome contains alarming levels of ARGs associated with clinically relevant antibiotics harbored by bacteria commonly responsible for nosocomial infections. Colonization of the breastfed infant gut by a single strain of B. longum subsp infantis had profound impacts on the fecal metagenome, including reduction in ARGs and reduction of potential pathogens. These findings highlight the importance of developing novel approaches to limit the spread of ARGs among clinically relevant bacteria and the relevance of an additional approach in the effort to solve AR globally.Funding: Evolve BioSystems provided Funding: for this study.Disclosures: Giorgio Casaburi reports salary from Evolve BioSystems.

scholarly journals Bacteriophage selection against a plasmid-encoded sex apparatus leads to the loss of antibiotic-resistance plasmids

2011 ◽  
Vol 7 (6) ◽  
pp. 902-905 ◽  
Author(s):  
Matti Jalasvuori ◽  
Ville-Petri Friman ◽  
Anne Nieminen ◽  
Jaana K. H. Bamford ◽  
Angus Buckling
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Bacterial Species ◽  
Low Frequency ◽  
Antibiotic Resistance Genes ◽  
Resistant Bacteria ◽  
Bacterial Cells ◽  
Antibiotic Resistant ◽  
Resistance Plasmids ◽  
Resistant Mutants

Antibiotic-resistance genes are often carried by conjugative plasmids, which spread within and between bacterial species. It has long been recognized that some viruses of bacteria (bacteriophage; phage) have evolved to infect and kill plasmid-harbouring cells. This raises a question: can phages cause the loss of plasmid-associated antibiotic resistance by selecting for plasmid-free bacteria, or can bacteria or plasmids evolve resistance to phages in other ways? Here, we show that multiple antibiotic-resistance genes containing plasmids are stably maintained in both Escherichia coli and Salmonella enterica in the absence of phages, while plasmid-dependent phage PRD1 causes a dramatic reduction in the frequency of antibiotic-resistant bacteria. The loss of antibiotic resistance in cells initially harbouring RP4 plasmid was shown to result from evolution of phage resistance where bacterial cells expelled their plasmid (and hence the suitable receptor for phages). Phages also selected for a low frequency of plasmid-containing, phage-resistant bacteria, presumably as a result of modification of the plasmid-encoded receptor. However, these double-resistant mutants had a growth cost compared with phage-resistant but antibiotic-susceptible mutants and were unable to conjugate. These results suggest that bacteriophages could play a significant role in restricting the spread of plasmid-encoded antibiotic resistance.

scholarly journals Analytical Performance of Multiplexed Screening Test for 10 Antibiotic Resistance Genes from Perianal Swab Samples

2016 ◽  
Vol 62 (2) ◽  
pp. 353-359 ◽  
Author(s):  
G Terrance Walker ◽  
Tony J Rockweiler ◽  
Rossio K Kersey ◽  
Kelly L Frye ◽  
Susan R Mitchner ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Test Performance ◽  
Health Care Systems ◽  
Bacterial Species ◽  
Antibiotic Resistance Gene ◽  
Antibiotic Resistance Genes ◽  
Resistant Bacteria ◽  
Gene Test

Abstract BACKGROUND Multiantibiotic-resistant bacteria pose a threat to patients and place an economic burden on health care systems. Carbapenem-resistant bacilli and extended-spectrum β-lactamase (ESBL) producers drive the need to screen infected and colonized patients for patient management and infection control. METHODS We describe a multiplex microfluidic PCR test for perianal swab samples (Acuitas® MDRO Gene Test, OpGen) that detects the vancomycin-resistance gene vanA plus hundreds of gene subtypes from the carbapenemase and ESBL families Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), Verona integron-mediated metallo-β-lactamase (VIM), imipenemase metallo-β-lactamase (IMP), OXA-23, OXA-48, OXA-51, CTX-M-1, and CTX-M-2, regardless of the bacterial species harboring the antibiotic resistance. RESULTS Analytical test sensitivity per perianal swab is 11–250 CFU of bacteria harboring the antibiotic resistance genes. Test throughput is 182 samples per test run (1820 antibiotic resistance gene family results). We demonstrate reproducible test performance and 100% gene specificity for 265 clinical bacterial organisms harboring a variety of antibiotic resistance genes. CONCLUSIONS The Acuitas MDRO Gene Test is a sensitive, specific, and high-throughput test to screen colonized patients and diagnose infections for several antibiotic resistance genes directly from perianal swab samples, regardless of the bacterial species harboring the resistance genes.

scholarly journals 1420. A One Health Approach Examining the Potential Linkage between Agricultural Livestock and Human Antibiotic Resistance at the Watershed Level

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S716-S717
Author(s):  
Linsey M Donner ◽  
Xu Li ◽  
Daniel D Snow ◽  
Jodi L Sangster ◽  
Zachery R Staley ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
One Health ◽  
Bacterial Species ◽  
Antibiotic Resistance Gene ◽  
Agricultural Watershed ◽  
Resistant Bacteria ◽  
Organic Chemical ◽  
Drug Resistant ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant

Abstract Background Antibiotic resistance is a significant public health threat and widespread use of antibiotics in agriculture is increasing the concern about agricultural contributions to the dissemination of antibiotic resistant bacteria. Of concern is the level of exposure to antibiotics and antibiotic-resistant bacteria in the watershed. Consequently, adopting a One Health approach to measure antibiotic levels and identify antibiotic resistance gene (ARG) transfer at the human, animal and environmental interfaces is essential to better understand how antibiotic resistance is spread. Methods In this project, antibiotic levels were measured using passive organic chemical integrative samplers (POCIS) for 30-day periods from August – November 2018 from Elkhorn River and Shell Creek watersheds in Nebraska (Figure 1). In addition, whole genome sequences of bacterial isolates cultured from the watersheds were assessed to identify ARGs present on mobile genetic elements (MGE) that had &gt;95% similarity to mobile ARG present in isolates recorded in the NCBI GenBank database was identified using ResFinder. Figure 1. Sampling locations within the two watersheds. Results The study demonstrated significant antibiotic levels present throughout the watershed, with five of them associated with human usage (Table 1). In addition, seasonally based drug-resistant bacterial species was associated with specific antibiotic levels in the watershed (Figure 2). Mobile ARGs were detected in 87.5% of isolates collected from the Elkhorn River and 80.0% within Shell Creek (Figure 3). Table 1. Pharmaceutical levels in the watershed Figure 2. Antibiotic levels and drug-resistant bacteria in the watershed Figure 3. Antibiotic resistance observed from each isolate at every sampling date and site. A colored bar denotes that resistance to that antibiotic was observed. Conclusion These results present evidence of transfer of highly mobile ARGs between environment, clinical, and animal-associated bacteria and highlight the need for a One Health perspective in assessing the spread of antibiotic resistance. The presence of significant levels of antibiotics persisting in this agricultural watershed points out the need for ongoing monitoring of compliance with the Food and Drug Administration (FDA) recommendation of veterinarian oversight of the use of antibiotics in the use of veterinary feed directive applications. Disclosures All Authors: No reported disclosures

scholarly journals Prevalence of Diversified Antibiotic Resistant Bacteria within Sanitation Related Facilities of Human Populated Workplaces in Abbottabad

2020 ◽  
Author(s):  
Jawad Ali ◽  
Malik Owais Ullah Awan ◽  
Gulcin Akca ◽  
Iftikhar Zeb ◽  
Bilal AZ Amin ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Bacterial Resistance ◽  
Bacterial Species ◽  
Resistant Bacteria ◽  
Rrna Gene ◽  
Beta Lactam ◽  
Bacterial Strains ◽  
Antibiotic Resistant Bacteria ◽  
Sensitivity Testing ◽  
Antibiotic Resistant

AbstractAntibiotics discovery was a significant breakthrough in the field of therapeutic medicines, but the over (mis)use of such antibiotics (n parallel) caused the increasing number of resistant bacterial species at an ever-higher rate. This study was thus devised to assess the multi-drug resistant bacteria present in sanitation-related facilities in human workplaces. In this regard, samples were collected from different gender, location, and source-based facilities, and subsequent antibiotic sensitivity testing was performed on isolated bacterial strains. Four classes of the most commonly used antibiotics i.e., β-lactam, Aminoglycosides, Macrolides, and Sulphonamides, were evaluated against the isolated bacteria.The antibiotic resistance profile of different (70) bacterial strains showed that the antibiotic resistance-based clusters also followed the grouping based on their isolation sources, mainly the gender. Twenty-three bacterial strains were further selected for their 16s rRNA gene based molecular identification and for phylogenetic analysis to evaluate the taxonomic evolution of antibiotic resistant bacteria. Moreover, the bacterial resistance to Sulphonamides and beta lactam was observed to be the most and to Aminoglycosides and macrolides as the least. Plasmid curing was also performed for MDR bacterial strains, which significantly abolished the resistance potential of bacterial strains for different antibiotics. These curing results suggested that the antibiotic resistance determinants in these purified bacterial strains are present on respective plasmids. Altogether, the data suggested that the human workplaces are the hotspot for the prevalence of MDR bacteria and thus may serve the source of horizontal gene transfer and further transmission to other environments.

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