scholarly journals Antimicrobial resistance three ways: healthcare crisis, major concepts and the relevance of biofilms

2019 ◽  
Vol 95 (8) ◽  
Author(s):  
Paula Jorge ◽  
Andreia Patrícia Magalhães ◽  
Tânia Grainha ◽  
Diana Alves ◽  
Ana Margarida Sousa ◽  
...  

ABSTRACTWorldwide, infections are resuming their role as highly effective killing diseases, as current treatments are failing to respond to the growing problem of antimicrobial resistance (AMR). The social and economic burden of AMR seems ever rising, with health- and research-related organizations rushing to collaborate on a worldwide scale to find effective solutions. Resistant bacteria are spreading even in first-world nations, being found not only in healthcare-related settings, but also in food and in the environment. In this minireview, the impact of AMR in healthcare systems and the major bacteria behind it are highlighted. Ecological aspects of AMR evolution and the complexity of its molecular mechanisms are explained. Major concepts, such as intrinsic, acquired and adaptive resistance, as well as tolerance and heteroresistance, are also clarified. More importantly, the problematic of biofilms and their role in AMR, namely their main resistance and tolerance mechanisms, are elucidated. Finally, some of the most promising anti-biofilm strategies being investigated are reviewed. Much is still to be done regarding the study of AMR and the discovery of new anti-biofilm strategies. Gladly, considerable research on this topic is generated every day and increasingly concerted actions are being engaged globally to try and tackle this problem.

This volume provides examines anarchist responses to the First World War. The collection is divided into three sections. The first examines the interventionist debate, focusing on the acrimonious disputes between Peter Kropotkin and Errico Malatesta which split the anarchist movement in 1914. The second discusses the impact of the war and the Bolshevik revolution, presenting a historical analysis of German, Dutch, French and US movements and conceptual analysis of just war and intervention, prefiguration, nationalism, internationalism, transnationalism, anti-colonialism, pacifism and terrorism. The final section focuses on anti-militarism and discusses no-conscription campaigns, anti-war/anti-capitalist cultural resistance and ideas of memory and war myths, centring on the experiences of Herbert Read. The book discusses the impact of the war on anarchism by looking at the social, cultural and geo-political changes that the war hastened, promoting forms of socialism that marginalized anarchist ideas, but argues that even while the war destroyed many domestic movements it also contributed to a re-framing of anarchist ideas. The book shows how the bitter divisions about the war and the experience of being caught on the wrong side of the Bolshevik Revolution encouraged anarchists to reaffirm their deeply-held rejection of vanguard socialism and develop new strategies that drew on a plethora of anti-war activities. The currents of ideas that emerged from anarchism's apparent obsolescence were crystallised during the war.


2021 ◽  
Author(s):  
Harry Pickering ◽  
John D. Hart ◽  
Sarah Burr ◽  
Richard Stabler ◽  
Ken Maleta ◽  
...  

AbstractBackgroundMass drug administration (MDA) with azithromycin is the primary strategy for global trachoma control efforts. Numerous studies have reported secondary effects of MDA with azithromycin, including reductions in childhood mortality, diarrhoeal disease and malaria. Most recently, the MORDOR clinical trial demonstrated that MDA led to an overall reduction in all-cause childhood mortality in targeted communities. There is however concern about the potential of increased antimicrobial resistance in treated communities.MethodsThis study evaluated the impact of azithromycin MDA on the prevalence of gastrointestinal carriage of macrolide-resistant bacteria in communities within the MORDOR Malawi study, additionally profiling changes in the gut microbiome after treatment. For faecal metagenomics, 60 children were sampled prior to treatment and 122 children after four rounds of MDA, half receiving azithromycin and half placebo.FindingsThe proportion of bacteria carrying macrolide resistance increased after azithromycin treatment; the effect was enhanced in children treated within six months of sampling. Diversity and global community structure of the gut was minimally impacted by treatment, however abundance of several species was altered by treatment. Notably, the putative human enteropathogen Escherichia albertii was more abundant after treatment.InterpretationThe impacts of MDA with azithromycin, including increased carriage of macrolide-resistant bacteria, were enhanced in children treated more recently, suggesting effects may be transient. Increased abundance of enteropathogenic Escherichia species after treatment requires further, higher resolution investigation. Future studies should focus on the number of treatments and administration schedule to ensure clinical benefits continue to outweigh costs in antimicrobial resistance carriage.FundingBill and Melinda Gates Foundation


Author(s):  
Shikha Kapil ◽  
Tarun Kumar ◽  
Vipasha Sharma

Antimicrobial resistance is one of the leading challenges in the human healthcare segment. Advances in antimicrobial resistance studies have revealed various intrinsic, adaptive or acquired factors to be involved for pathogenicity. Antimicrobial agents are either bactericidal or bacteriostatic in action and prescribed according to the mode of action. Various factors are confined for the antimicrobial activity of these agents via biochemical, mechanical, physiological and molecular mechanisms. Microbial cell expresses a number of alternates responsible for the evolution of resistance against these agent activities involving cell surface modifications, enzyme inhibitions, modifications in efflux system, protein carriers and mutations in nucleic acids. Apart from this, the successful adaptations of such microbes have also been observed with the transfer of responsible genes through miscellaneous operations such as vertical evolution, horizontal gene transfer, co-selection, compensatory and random mutation. In addition, alterations or modifications in biochemical and physiological mechanisms at cellular levels are also responsible for antibiotic resistance. This article briefly shows the present scenario of antimicrobial resistance and the alternatives to overcome this global issue in future.


2020 ◽  
Vol 75 (12) ◽  
pp. 3665-3674 ◽  
Author(s):  
Christina Routsi ◽  
Aikaterini Gkoufa ◽  
Kostoula Arvaniti ◽  
Stelios Kokkoris ◽  
Alexandros Tourtoglou ◽  
...  

Abstract Background De-escalation of empirical antimicrobial therapy, a key component of antibiotic stewardship, is considered difficult in ICUs with high rates of antimicrobial resistance. Objectives To assess the feasibility and the impact of antimicrobial de-escalation in ICUs with high rates of antimicrobial resistance. Methods Multicentre, prospective, observational study in septic patients with documented infections. Patients in whom de-escalation was applied were compared with patients without de-escalation by the use of a propensity score matching by SOFA score on the day of de-escalation initiation. Results A total of 262 patients (mean age 62.2 ± 15.1 years) were included. Antibiotic-resistant pathogens comprised 62.9%, classified as MDR (12.5%), extensively drug-resistant (49%) and pandrug-resistant (1.2%). In 97 (37%) patients de-escalation was judged not feasible in view of the antibiotic susceptibility results. Of the remaining 165 patients, judged as patients with de-escalation possibility, de-escalation was applied in 60 (22.9%). These were matched to an equal number of patients without de-escalation. In this subset of 120 patients, de-escalation compared with no de-escalation was associated with lower all-cause 28 day mortality (13.3% versus 36.7%, OR 0.27, 95% CI 0.11–0.66, P = 0.006); ICU and hospital mortality were also lower. De-escalation was associated with a subsequent collateral decrease in the SOFA score. Cox multivariate regression analysis revealed de-escalation as a significant factor for 28 day survival (HR 0.31, 95% CI 0.14–0.70, P = 0.005). Conclusions In ICUs with high levels of antimicrobial resistance, feasibility of antimicrobial de-escalation was limited because of the multi-resistant pathogens isolated. However, when de-escalation was feasible and applied, it was associated with lower mortality.


mBio ◽  
2015 ◽  
Vol 6 (6) ◽  
Author(s):  
Justine L. Murray ◽  
Taejoon Kwon ◽  
Edward M. Marcotte ◽  
Marvin Whiteley

ABSTRACT Antimicrobial-resistant bacteria pose a serious threat in the clinic. This is particularly true for opportunistic pathogens that possess high intrinsic resistance. Though many studies have focused on understanding the acquisition of bacterial resistance upon exposure to antimicrobials, the mechanisms controlling intrinsic resistance are not well understood. In this study, we subjected the model opportunistic superbug Pseudomonas aeruginosa to 14 antimicrobials under highly controlled conditions and assessed its response using expression- and fitness-based genomic approaches. Our results reveal that gene expression changes and mutant fitness in response to sub-MIC antimicrobials do not correlate on a genomewide scale, indicating that gene expression is not a good predictor of fitness determinants. In general, fewer fitness determinants were identified for antiseptics and disinfectants than for antibiotics. Analysis of gene expression and fitness data together allowed the prediction of antagonistic interactions between antimicrobials and insight into the molecular mechanisms controlling these interactions. IMPORTANCE Infections involving multidrug-resistant pathogens are difficult to treat because the therapeutic options are limited. These infections impose a significant financial burden on infected patients and on health care systems. Despite years of antimicrobial resistance research, we lack a comprehensive understanding of the intrinsic mechanisms controlling antimicrobial resistance. This work uses two fine-scale genomic approaches to identify genetic loci important for antimicrobial resistance of the opportunistic pathogen Pseudomonas aeruginosa. Our results reveal that antibiotics have more resistance determinants than antiseptics/disinfectants and that gene expression upon exposure to antimicrobials is not a good predictor of these resistance determinants. In addition, we show that when used together, genomewide gene expression and fitness profiling can provide mechanistic insights into multidrug resistance mechanisms.


2021 ◽  
Vol 83 (4) ◽  
Author(s):  
Christopher W. Lanyon ◽  
John R. King ◽  
Dov J. Stekel ◽  
Rachel L. Gomes

AbstractThe ecological and human health impact of antibiotic use and the related antimicrobial resistance (AMR) in animal husbandry is poorly understood. In many countries, there has been considerable pressure to reduce overall antibiotic use in agriculture or to cease or minimise use of human critical antibiotics. However, a more nuanced approach would consider the differential impact of use of different antibiotic classes; for example, it is not known whether reduced use of bacteriostatic or bacteriolytic classes of antibiotics would be of greater value. We have developed an ordinary differential equation model to investigate the effects of farm practice on the spread and persistence of AMR in the dairy slurry tank environment. We model the chemical fate of bacteriolytic and bacteriostatic antibiotics within the slurry and their effect on a population of bacteria, which are capable of resistance to both types of antibiotic. Through our analysis, we find that changing the rate at which a slurry tank is emptied may delay the proliferation of multidrug-resistant bacteria by up to five years depending on conditions. This finding has implications for farming practice and the policies that influence waste management practices. We also find that, within our model, the development of multidrug resistance is particularly sensitive to the use of bacteriolytic antibiotics, rather than bacteriostatic antibiotics, and this may be cause for controlling the usage of bacteriolytic antibiotics in agriculture.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S153-S153
Author(s):  
Elizabeth McDougal ◽  
Julie Ann Justo ◽  
Joseph Kohn ◽  
P B Bookstaver ◽  
Hana R Winders ◽  
...  

Abstract Background There are several clinical tools for prediction of antimicrobial resistance. However, their utility in management of bloodstream infections (BSI) due to resistant bacteria remains unclear. This quasi-experimental cohort examined the impact of utilization of the extended-spectrum beta-lactamase (ESBL) prediction score on time to initiation of appropriate antimicrobial therapy (AAT) in BSI due to ceftriaxone-resistant (CRO-R) Enterobacterales. Methods Adults with first episodes of monomicrobial BSI due to CRO-R Enterobacterales at Prisma Health-Midlands Hospitals in South Carolina from January 2010 to December 2017 were included. Antimicrobial stewardship intervention was implemented in January 2014 consisting of real-time alerts for positive blood cultures and rapid diagnostics for identification of bloodstream isolates. The ESBL prediction score was used to stratify risk of resistance prior to conventional antimicrobial susceptibility results. Student’s t-test was used to compare mean time to AAT before and after intervention. Results Among 92 patients with BSI due to CRO-R Enterobacterales, median age was 66 years, 52 (57%) were men, 68 (74%) had community-onset BSI, and 52 (57%) had urinary source of infection. Escherichia coli 52 (57%) and Klebsiella species 27 (29%) were the most common bloodstream isolates and the majority 63 (68%) produced ESBLs. There were no significant differences in demographics or clinical characteristics of patients before (n=45) and after (n=47) antimicrobial stewardship intervention. Mean time to AAT was 3.2 days prior and 1.7 days after utilization of ESBL prediction score (p=0.021). Results were consistent among ESBL-producing Enterobacterales (time to AAT 2.8 before and 1.8 days after intervention, p=0.025). Conclusion Utilization of the ESBL prediction score as part of a real-time antimicrobial stewardship intervention significantly reduced time to AAT in BSI due to CRO-R and ESBL-producing Enterobacterales. The ESBL prediction score represents a viable tool to improve antimicrobial management in clinical settings that lack access to multiplex PCRs for detection of antimicrobial resistance genes and novel methods for rapid phenotypic antimicrobial susceptibility testing. Disclosures Julie Ann Justo, PharmD, MS, BCPS-AQ ID, bioMerieux (Speaker’s Bureau)TRC Healthcare (Speaker’s Bureau)


2021 ◽  
Vol 6 (1) ◽  
pp. 11
Author(s):  
Hamid Bokhary ◽  
Krisna N. A. Pangesti ◽  
Harunor Rashid ◽  
Moataz Abd El Ghany ◽  
Grant A. Hill-Cawthorne

There is increasing evidence that human movement facilitates the global spread of resistant bacteria and antimicrobial resistance (AMR) genes. We systematically reviewed the literature on the impact of travel on the dissemination of AMR. We searched the databases Medline, EMBASE and SCOPUS from database inception until the end of June 2019. Of the 3052 titles identified, 2253 articles passed the initial screening, of which 238 met the inclusion criteria. The studies covered 30,060 drug-resistant isolates from 26 identified bacterial species. Most were enteric, accounting for 65% of the identified species and 92% of all documented isolates. High-income countries were more likely to be recipient nations for AMR originating from middle- and low-income countries. The most common origin of travellers with resistant bacteria was Asia, covering 36% of the total isolates. Beta-lactams and quinolones were the most documented drug-resistant organisms, accounting for 35% and 31% of the overall drug resistance, respectively. Medical tourism was twice as likely to be associated with multidrug-resistant organisms than general travel. International travel is a vehicle for the transmission of antimicrobial resistance globally. Health systems should identify recent travellers to ensure that adequate precautions are taken.


Gut Pathogens ◽  
2022 ◽  
Vol 14 (1) ◽  
Author(s):  
Harry Pickering ◽  
John D. Hart ◽  
Sarah Burr ◽  
Richard Stabler ◽  
Ken Maleta ◽  
...  

Abstract Background Mass drug administration (MDA) with azithromycin is the primary strategy for global trachoma control efforts. Numerous studies have reported secondary effects of MDA with azithromycin, including reductions in childhood mortality, diarrhoeal disease and malaria. Most recently, the MORDOR clinical trial demonstrated that MDA led to an overall reduction in all-cause childhood mortality in targeted communities. There is however concern about the potential of increased antimicrobial resistance in treated communities. This study evaluated the impact of azithromycin MDA on the prevalence of gastrointestinal carriage of macrolide-resistant bacteria in communities within the MORDOR Malawi study, additionally profiling changes in the gut microbiome after treatment. For faecal metagenomics, 60 children were sampled prior to treatment and 122 children after four rounds of MDA, half receiving azithromycin and half placebo. Results The proportion of bacteria carrying macrolide resistance increased after azithromycin treatment. Diversity and global community structure of the gut was minimally impacted by treatment, however abundance of several species was altered by treatment. Notably, the putative human enteropathogen Escherichia albertii was more abundant after treatment. Conclusions MDA with azithromycin increased carriage of macrolide-resistant bacteria, but had limited impact on clinically relevant bacteria. However, increased abundance of enteropathogenic Escherichia species after treatment requires further, higher resolution investigation. Future studies should focus on the number of treatments and administration schedule to ensure clinical benefits continue to outweigh costs in antimicrobial resistance carriage. Trial registration ClinicalTrial.gov, NCT02047981. Registered January 29th 2014, https://clinicaltrials.gov/ct2/show/NCT02047981


Author(s):  
Dominic Poulin-Laprade ◽  
Jean-Simon Brouard ◽  
Nathalie Gagnon ◽  
Annie Turcotte ◽  
Alexandra Langlois ◽  
...  

Pigs are major reservoirs of resistant Enterobacteriaceae that can reach humans through consumption of contaminated meat or vegetables grown in manure-fertilized soil. Samples were collected from sows during lactation and their piglets at five time points spanning the production cycle. Cefotaxime-resistant bacteria were quantified and isolated from feed, feces, manures and carcasses of pigs reared with penicillin-using or antibiotic-free husbandries. The isolates were characterized by antibiotic susceptibility testing, whole genome sequencing and conjugation assays. The extended spectrum β-lactamase (ESBL) phenotype was more frequent in isolates originating from antibiotic-free animals, while the bacteria isolated from penicillin-using animals were on average resistant to a greater number of antibiotics. The ESBL-encoding genes identified were blaCTX-M-1, blaCTX-M-15 and blaCMY-2 and they co-localised on plasmids with various genes encoding resistance to ß-lactams, co-trimoxazole, phenicols and tetracycline, all antibiotics used in pig production. Groups of genes conferring the observed resistance and the mobile elements disseminating multidrug resistance were determined. The observed resistance to ß-lactams was mainly due to the complementary actions of penicillin-binding proteins, an efflux pump and ß-lactamases. Most resistance determinants were shared by animals raised with or without antimicrobials. This suggests a key contribution of indigenous enterobacteria maternally transmitted along the sow lineage, regardless of antimicrobial use. It is unclear if the antimicrobial resistance observed in the enterobacteria populations of the commercial pig herds studied were present before the use of antibiotics, or the extent to which historical antimicrobial use exerted a selective pressure defining the resistant bacterial populations in farms using penicillin prophylaxis. Importance: Antimicrobial resistance is a global threat that needs to be fought on numerous fronts along the One Health continuum. Vast quantities of antimicrobials are used in agriculture to ensure animal welfare and productivity, and are arguably a driving force for the persistence of environmental and food-borne resistant bacteria. This study evaluated the impact of conventional, organic and other antibiotic-free husbandry practices on the frequency and nature of antimicrobial resistance genes and multidrug resistant enterobacteria. It provides knowledge about the relative contribution of specific resistance determinants to observed antibiotic resistance. It also showed the clear co-selection of genes coding for extended-spectrum beta-lactamases and genes coding for the resistance to antibiotics commonly used for prophylaxis or in curative treatments in pig operations.


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