scholarly journals Stereoselective Bacterial Metabolism of Antibiotics in Environmental Bacteria – A Novel Biochemical Workflow

2021 ◽  
Vol 12 ◽  
Author(s):  
Felicity C. T. Elder ◽  
Edward J. Feil ◽  
Ben Pascoe ◽  
Samuel K. Sheppard ◽  
Jason Snape ◽  
...  

Although molecular genetic approaches have greatly increased our understanding of the evolution and spread of antibiotic resistance genes, there are fewer studies on the dynamics of antibiotic – bacterial (A-B) interactions, especially with respect to stereochemistry. Addressing this knowledge gap requires an interdisciplinary synthesis, and the development of sensitive and selective analytical tools. Here we describe SAM (stereoselective antimicrobial metabolism) workflow, a novel interdisciplinary approach for assessing bacterial resistance mechanisms in the context of A-B interactions that utilise a combination of whole genome sequencing and mass spectrometry. Chloramphenicol was used to provide proof-of-concept to demonstrate the importance of stereoselective metabolism by resistant environmental bacteria. Our data shows that chloramphenicol can be stereoselectively transformed via microbial metabolism with R,R-(-)-CAP being subject to extensive metabolic transformation by an environmental bacterial strain. In contrast S,S-(+)-CAP is not metabolised by this bacterial strain, possibly due to the lack of previous exposure to this isomer in the absence of historical selective pressure to evolve metabolic capacity.

2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Willian K Oliveira ◽  
Mariana Ferrarini ◽  
Luis G Morello ◽  
Helisson Faoro

Abstract Bacterial resistance to antibiotics is a global public health problem. Its association with bloodstream infections is even more severe and may easily evolve to sepsis. To improve our response to these bacteria, it is essential to gather thorough knowledge on the main pathogens along with the main mechanisms of resistance they carry. In this paper, we performed a large meta-analysis of 3872 bacterial genomes isolated from blood samples, from which we identified 71 745 antibiotic resistance genes (ARGs). Taxonomic analysis showed that Proteobacteria and Firmicutes phyla, and the species Klebsiella pneumoniae and Staphylococcus aureus were the most represented. Comparison of ARGs with the Resfams database showed that the main mechanism of antibiotic resistance is mediated by efflux pumps. Clustering analysis between resistome of blood and soil-isolated bacteria showed that there is low identity between transport and efflux proteins between bacteria from these environments. Furthermore, a correlation analysis among all features showed that K. pneumoniae and S. aureus formed two well-defined clusters related to the resistance mechanisms, proteins and antibiotics. A retrospective analysis has shown that the average number of ARGs per genome has gradually increased. The results demonstrate the importance of comprehensive studies to understand the antibiotic resistance phenomenon.


2015 ◽  
Vol 41 (4) ◽  
pp. 23-32 ◽  
Author(s):  
Aleksandra Ziembińska-Buczyńska ◽  
Ewa Felis ◽  
Justyna Folkert ◽  
Anna Meresta ◽  
Dominika Stawicka ◽  
...  

AbstractAntibiotics are a group of substances potentially harmful to the environment. They can play a role in bacterial resistance transfer among pathogenic and non-pathogenic bacteria. In this experiment three representatives of medically important chemotherapeutics, confirmed to be present in high concentrations in wastewater treatment plants with HPLC analysis were used: erythromycin, sulfamethoxazole and trimethoprim. Erythromycin concentration in activated sludge was not higher than 20 ng L−1. N-acetylo-sulfamethoxazole concentration was 3349 ± 719 in winter and 2933 ± 429 ng L−1in summer. Trimethoprim was present in wastewater at concentrations 400 ± 22 and 364 ± 60 ng L−1, respectively in winter and summer. Due to a wide variety of PCR-detectable resistance mechanisms towards these substances, the most common found in literature was chosen. For erythromycin:ermandmefgenes, for sulfamethoxazole:sul1,sul2,sul3genes, in the case of trimethoprim resistancedhfrA1anddhfr14were used in this study. The presence of resistance genes were analyzed in pure strains isolated from activated sludge and in the activated sludge sample itself. The research revealed that the value of minimal inhibitory concentration (MIC) did not correspond with the expected presence of more than one resistance mechanisms. Most of the isolates possessed only one of the genes responsible for a particular chemotherapeutic resistance. It was confirmed that it is possible to monitor the presence of resistance genes directly in activated sludge using PCR. Due to the limited isolates number used in the experiment these results should be regarded as preliminary.


Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 874
Author(s):  
Periyasamy Sivalingam ◽  
John Poté ◽  
Kandasamy Prabakar

Over the past decades, the rising antibiotic resistance bacteria (ARB) are continuing to emerge as a global threat due to potential public health risk. Rapidly evolving antibiotic resistance and its persistence in the environment, have underpinned the need for more studies to identify the possible sources and limit the spread. In this context, not commonly studied and a neglected genetic material called extracellular DNA (eDNA) is gaining increased attention as it can be one of the significant drivers for transmission of extracellular ARGS (eARGs) via horizontal gene transfer (HGT) to competent environmental bacteria and diverse sources of antibiotic-resistance genes (ARGs) in the environment. Consequently, this review highlights the studies that address the environmental occurrence of eDNA and encoding eARGs and its impact on the environmental resistome. In this review, we also brief the recent dedicated technological advancements that are accelerating extraction of eDNA and the efficiency of treatment technologies in reducing eDNA that focuses on environmental antibiotic resistance and potential ecological health risk.


Author(s):  
Cláudia A. Ribeiro ◽  
Luke A. Rahman ◽  
Louis G. Holmes ◽  
Ayrianna M. Woody ◽  
Calum M. Webster ◽  
...  

AbstractThe spread of multidrug-resistance in Gram-negative bacterial pathogens presents a major clinical challenge, and new approaches are required to combat these organisms. Nitric oxide (NO) is a well-known antimicrobial that is produced by the immune system in response to infection, and numerous studies have demonstrated that NO is a respiratory inhibitor with both bacteriostatic and bactericidal properties. However, given that loss of aerobic respiratory complexes is known to diminish antibiotic efficacy, it was hypothesised that the potent respiratory inhibitor NO would elicit similar effects. Indeed, the current work demonstrates that pre-exposure to NO-releasers elicits a > tenfold increase in IC50 for gentamicin against pathogenic E. coli (i.e. a huge decrease in lethality). It was therefore hypothesised that hyper-sensitivity to NO may have arisen in bacterial pathogens and that this trait could promote the acquisition of antibiotic-resistance mechanisms through enabling cells to persist in the presence of toxic levels of antibiotic. To test this hypothesis, genomics and microbiological approaches were used to screen a collection of E. coli clinical isolates for antibiotic susceptibility and NO tolerance, although the data did not support a correlation between increased carriage of antibiotic resistance genes and NO tolerance. However, the current work has important implications for how antibiotic susceptibility might be measured in future (i.e. ± NO) and underlines the evolutionary advantage for bacterial pathogens to maintain tolerance to toxic levels of NO.


2021 ◽  
Vol 22 (13) ◽  
pp. 6891
Author(s):  
João S. Rebelo ◽  
Célia P. F. Domingues ◽  
Francisco Dionisio ◽  
Manuel C. Gomes ◽  
Ana Botelho ◽  
...  

Recently, much attention has been paid to the COVID-19 pandemic. Yet bacterial resistance to antibiotics remains a serious and unresolved public health problem that kills hundreds of thousands of people annually, being an insidious and silent pandemic. To contain the spreading of the SARS-CoV-2 virus, populations confined and tightened hygiene measures. We performed this study with computer simulations and by using mobility data of mobile phones from Google in the region of Lisbon, Portugal, comprising 3.7 million people during two different lockdown periods, scenarios of 40 and 60% mobility reduction. In the simulations, we assumed that the network of physical contact between people is that of a small world and computed the antibiotic resistance in human microbiomes after 180 days in the simulation. Our simulations show that reducing human contacts drives a reduction in the diversity of antibiotic resistance genes in human microbiomes. Kruskal–Wallis and Dunn’s pairwise tests show very strong evidence (p < 0.000, adjusted using the Bonferroni correction) of a difference between the four confinement regimes. The proportion of variability in the ranked dependent variable accounted for by the confinement variable was η2 = 0.148, indicating a large effect of confinement on the diversity of antibiotic resistance. We have shown that confinement and hygienic measures, in addition to reducing the spread of pathogenic bacteria in a human network, also reduce resistance and the need to use antibiotics.


2020 ◽  
Vol 55 (4) ◽  
pp. 271-276
Author(s):  
Ewa Młodzińska ◽  
Waleria Hryniewicz

The increase in bacterial resistance to antimicrobials is one of the most serious medical problems, therefore reliable identification in microbiological laboratories is important. The Polish National External Quality Assessment Scheme in Microbiological Diagnostics – POLMICRO programme is organized by the Centre of Quality Control in Microbiology (CQCM) enables the assessment of the competence of Polish microbiological laboratories in the field of identification, determination of susceptibility and detection of drug resistance mechanisms. This work presents the assessment of the results of identification and determination of S. pneumoniae antimicrobial susceptibility obtained by Polish laboratories during the 20 years of experience of the POLMICRO programme.


DICP ◽  
1989 ◽  
Vol 23 (7-8) ◽  
pp. 556-561 ◽  
Author(s):  
John A. Bosso

Bacterial resistance to antibiotics has become an increasingly distressing problem over the last few decades. In this article, known resistance mechanisms are reviewed and the extent of the problem in both hospitals and nursing homes is addressed. Suggestions for preventing the further spread of this problem are presented.


2021 ◽  
Vol 14 (4) ◽  
pp. 52-59
Author(s):  
L. A. Katargina ◽  
V. V. Kadyshev ◽  
E. V. Denisova ◽  
E. A. Geraskina ◽  
A. V. Marakhonov ◽  
...  

Familial exudative vitreoretinopathy (FEVR)is a rare genetically heterogeneous disease with multiple types of inheritance (autosomal dominant, autosomal recessive, X-linked) and widely varying clinical features. Up to 40 % of cases of FEVR are associated with mutations of the FZD4 gene.Purpose: to investigate the clinical manifestations of FEVR in children with nucleotide sequence alterations in the FZD4 gene. Material and methods. The Helmholtz National Medical ResearchCenter of Eye Diseases and the ResearchCentre for MedicalGenetics conducted a joint in-depth ophthalmological examination of 18 patients aged from 3 weeks to 17 years with a diagnosis of FEVR, which included a detailed ophthalmoscopy under drug mydriasis, ultrasound and electrophysiological examination, photographic recording of fundus changes using RetCam and Fundus Foto. Molecular genetic examination was carried out by direct sequencing according to Sanger. Results. Nucleotide sequence alterations in the FZD4 gene were detected in 3 patients(16.7 %)from two unrelated families. In one family, a 12-year-old girl wasfound to display the firstsymptoms of ophthalmic pathology (reduced vision, strabismus) at the age of 3.5 years. In another family, the clinical manifestations of FZD4 gene mutations were observed in two children during the first year of life (at the age of 5 and 11 months).Conclusions. The clinical picture of 3 patients with detected changes in the nucleotide sequence of the FZD4 gene is characterized by early manifestation and bilateral asymmetric ophthalmoscopic damage. The results of the study indicate the need for a timely diagnosis of FEVR in young children, recommend an interdisciplinary approach to the study of the disease, which should contribute to a better understanding of pathogenesis, and the development of an effective diagnostic, treatment and rehabilitation algorithm.


2017 ◽  
Vol 15 (2) ◽  
pp. 140
Author(s):  
Yatnita Parama Cita ◽  
Dwi Hilda Putri

Tuberculosis (TB) is a serious disesase in the world. According to the WHO, it is estimated more than 3 million people die every year as a result of this infectious disease. One factor that causes diffi culty handling TB chemoteraphy is not effective against the bacteria Mycobacterium tuberculosis that causes TB . Effectiveness of treatment is often hampered by the emergence of bacterial resistance against M. Tuberculosis chemotherapy agents are given. From some research found that bacterial resistance may occur in more one type of chemotherapy agent also known as multi-drug resistance (MDR). Mycobacterium tuberculosis develop resistance mechanisms that are different from other bacteria in general. In prokaryotes, resistance is generally due to the transfer of genetic, either through plasmids,transposons and other. Reference sequence beta sub unit of RNAP protein M. Tuberculosis with accession number NP_215181.1 and M. tucerculosis rpoB gene with accession number NC_000962.3 used to obtain preliminary information from the data base www.ncbi.nlm.gov and www.uniprot.org . Mutation done according to several studies literature. Analysis of the composition, profi le, location and structure of protein using www.expasy.org, TMHMM and http://bioinf.cs.ucl.ac.uk/psipred. The primer design is done with Primer Design Program. Based on the analysis of mutation in the beta subunit of RNAP protein M. Tuberculosis, codon 531 (Ser ->Leu), it is known that mutations cause changes in some properties and structure of proteins. Possible changes affecting the nature of bacterial resistance to antibiotics rifampicin. However, further analysis needs to be done with the analysis of the docking technique.


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