scholarly journals Metagenomics: aid to combat antimicrobial resistance in diarrhea

Gut Pathogens ◽  
2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Rituparna De

Abstract Antimicrobial resistance (AMR) has emerged as an obstacle in the supple administration of antimicrobial agents to critical diarrheal patients. Most diarrheal pathogens have developed resistance against the major classes of antibiotics commonly used for assuaging diarrheal symptoms. Antimicrobial resistance develops when pathogens acquire antimicrobial resistance genes (ARGs) through genetic recombination from commensals and pathogens. These are the constituents of the complex microbiota in all ecological niches. The recombination events may occur in the environment or in the gut. Containment of AMR can be achieved through a complete understanding of the complex and diverse structure and function of the microbiota. Its taxonomic entities serve as focal points for the dissemination of antimicrobial resistance genetic determinants. Molecular methods complemented with culture-based diagnostics have been historically implemented to document these natural events. However, the advent of next-generation sequencing has revolutionized the field of molecular epidemiology. It has revolutionized the method of addressing relevant problems like diagnosis and surveillance of infectious diseases and the issue of antimicrobial resistance. Metagenomics is one such next-generation technique that has proved to be a monumental advancement in the area of molecular taxonomy. Current understanding of structure, function and dysbiosis of microbiota associated with antimicrobial resistance was realized due to its conception. This review describes the major milestones achieved due to the advent and implementation of this new technique in the context of antimicrobial resistance. These achievements span a wide panorama from the discovery of novel microorganisms to invention of translational value.

2021 ◽  
Vol 6 (4) ◽  
pp. 236-244
Author(s):  
Pier F. Indelli ◽  
Stefano Ghirardelli ◽  
Bruno Violante ◽  
Derek F. Amanatullah

Periprosthetic joint infections (PJI) represent one of the most catastrophic complications following total joint arthroplasty (TJA). The lack of standardized diagnostic tests and protocols for PJI is a challenge for arthroplasty surgeons. Next generation sequencing (NGS) is an innovative diagnostic tool that can sequence microbial deoxyribonucleic acids (DNA) from a synovial fluid sample: all DNA present in a specimen is sequenced in parallel, generating millions of reads. It has been shown to be extremely useful in a culture-negative PJI setting. Metagenomic NGS (mNGS) allows for universal pathogen detection, regardless of microbe type, in a 24–48-hour timeframe: in its nanopore-base variation, mNGS also allows for antimicrobial resistance characterization. Cell-free DNA (cfDNA) NGS, characterized by lack of the cell lysis step, has a fast run-time (hours) and, together with a high sensitivity and specificity in microorganism isolation, may provide information on the presence of antimicrobial resistance genes. Metagenomics and cfDNA testing have reduced the time needed to detect infecting bacteria and represent very promising technologies for fast PJI diagnosis. NGS technologies are revolutionary methods that could disrupt the diagnostic paradigm of PJI, but a comprehensive collection of clinical evidence is still needed before they become widely used diagnostic tools. Cite this article: EFORT Open Rev 2021;6:236-244. DOI: 10.1302/2058-5241.6.200099


2021 ◽  
Author(s):  
Lu Yang ◽  
Yingbo Shen ◽  
Junyao Jiang ◽  
Xueyang Wang ◽  
Dongyan Shao ◽  
...  

Abstract Antimicrobial agents have been used in meat production for decades and its consumption is considered an key driver for the emergence and dissemination of antimicrobial resistance (AMR). However, large-scale studies on AMR changes in animal isolates since the introduction of antimicrobial usage remain scarce. We applied whole genome sequencing analysis to 982 animal-derived Escherichia coli collected in China from 1970s to 2019 and found increasing trends for the presence of numerous antimicrobial resistance genes (ARGs), including those conferring resistance to critically important agents for veterinary (florfenicol and norfloxacin) and human medicine (colistin, cephalosporins, and meropenem). Extensive diversity and increasing complexity of ARGs and their associated mobile genetic elements (MGEs) such as plasmids were also observed. The plasmids, IncC, IncHI2, IncK, IncI, IncX and IncF played a key role as highly effective vehicles for disseminating ARGs. Correlation analysis also revealed an association between antimicrobial production and emergence of ARGs at a spatial and temporal level. Prohibiting or strictly curtailing antimicrobial use in animals will potentially negate the current trends of AMR as the bacterial genome is highly changeable and using different drugs of the same class, or even unrelated classes, may co-select for MGEs carrying a plethora of co-existing ARGs. Therefore, limiting or ceasing antimicrobial use in animals to control AMR requires careful consideration.


2009 ◽  
Vol 72 (5) ◽  
pp. 1082-1088 ◽  
Author(s):  
AHLEM JOUINI ◽  
KARIM BEN SLAMA ◽  
YOLANDA SÁENZ ◽  
NAOUEL KLIBI ◽  
DANIELA COSTA ◽  
...  

Phenotypic and genotypic characterization of antimicrobial resistance was conducted for 98 Escherichia coli isolates recovered from 40 food samples of animal origin (poultry, sheep, beef, fish, and others) obtained in supermarkets and local butcheries in Tunis during 2004 and 2005. Susceptibility to 15 antimicrobial agents was tested by disk diffusion and agar dilution methods, the mechanisms of resistance were evaluated using PCR and sequencing methods, and the clonal relationship among isolates was evaluated using pulsed-field gel electrophoresis. High resistance was detected to tetracycline, sulphonamides, nalidixic acid, ampicillin, streptomycin, and trimethoprim-sulfamethoxazole (29 to 43% of isolates), but all isolates were susceptible to cefotaxime, ceftazidime, cefoxitin, azthreonam, and amikacin. One-third of the isolates had multiresistant phenotypes (resistance to at least five different families of antimicrobial agents). Different variants of blaTEM, tet, sul, dfrA, aadA, and aac(3) genes were detected in most of the strains resistant to ampicillin, tetracycline, sulphonamide, trimethoprim, streptomycin, and gentamicin, respectively. The presence of class 1 and class 2 integrons was studied in 15 sulphonamide-resistant unrelated E. coli strains, and 14 of these strains harbored class 1 integrons with five different arrangements of gene cassettes, and a class 2 integron with the dfrA1 + sat + aadA1 arrangement was found in one strain. This study revealed the high diversity of antimicrobial resistance genes, some of them included in integrons, in E. coli isolates of food origin.


Author(s):  
João Pires ◽  
Jana S. Huisman ◽  
Sebastian Bonhoeffer ◽  
Thomas P. Van Boeckel

Next-generation sequencing has led to an exponential increase in the number of genomes deposited in public repositories. This growing volume of information presents opportunities to track the prevalence of genes conferring antimicrobial resistance (AMR), a growing threat to the health of humans and animals.


2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S436-S436
Author(s):  
Rachel Downey Quick ◽  
Kelli A Martinez ◽  
Susan M Russo ◽  
Sarah E McGwier ◽  
Rachel A Quirt ◽  
...  

Abstract Background Pathogen testing using next-generation sequencing of microbial cell-free DNA (NGS cfDNA) is a promising diagnostic tool to identify pathogens that might not be detected using conventional lab evaluation. Considering the cost of this test, it is important to determine when it is most useful to the plan of care (POC). Figure 1. Unit of admission among cases Figure 2. Patient characteristics in cases determined to be valuable and not valuable to the plan of care (POC) Methods In this retrospective study, we collected data from the medical charts of 50 consecutive NGS cfDNA tests in a free-standing children’s hospital. We evaluated patients for demographics, underlying conditions, diagnosis at time of testing, conventional laboratory testing and timing, medical treatment, and NGS cfDNA test results for clinical relevance or false negative results compared to conventional testing. The primary goal was to identify patients for whom the NGS cfDNA testing affected the POC. Charts were reviewed, and determinations regarding whether the result influenced the POC were confirmed by a provider. Results We were unable to differentiate patients with clinically valuable NGS cfDNA results (Fig 1 & 2). Among those with NGS cfDNA results valuable to the POC (n=22), both negative and positive testing guided POC (13 valuable negative vs. 9 diagnostic cases). In the total sample, 5 cases (10%) had a clinically relevant pathogen identified through conventional testing, but not through NGS cfDNA and 2 cases had antimicrobial resistance on culture, which is not detected by NGS cfDNA. Conclusion While we did not find a specific clinical profile for NGS cfDNA use, positive results were essential to the diagnosis in 18% of cases with otherwise negative laboratory evaluation for the pathogen identified in NGS cfDNA. Negative tests affected the POC in 26% of cases by avoiding unnecessary antimicrobials in high risk immunocompromised patients and patients that presented with low-risk of infection, but unclear disease process. Caution must be exercised with reliance on this test with respect to antimicrobial resistance and risk of false negative results. Disclosures All Authors: No reported disclosures


Author(s):  
Jalees A. Nasir ◽  
David J. Speicher ◽  
Robert A. Kozak ◽  
Hendrik N. Poinar ◽  
Matthew S. Miller ◽  
...  

SARS-CoV-2 is a novel betacoronavirus and the aetiological agent of the current COVID-19 outbreak that originated in Hubei Province, China. While polymerase chain reaction is the front-line tool for SARS-CoV-2 surveillance, application of amplification-free and culture-free methods for isolation of SARS-CoV-2 RNA, partnered with next-generation sequencing, would provide a useful tool for both surveillance and research of SARS-CoV-2. We here release into the public domain a set of bait capture hybridization probe sequences for enrichment of SARS-CoV-2 RNA from complex biological samples. These probe sequences have been designed using rigorous bioinformatics methods to provide sensitivity, accuracy, and minimal off-target hybridization. Probe design was based on existing, validated approaches for detecting antimicrobial resistance genes in complex samples and it is our hope that this SARS-CoV-2 bait capture platform, once validated by those with samples in hand, will be of aid in combating the current outbreak.


2016 ◽  
Vol 79 (11) ◽  
pp. 1884-1890 ◽  
Author(s):  
SANG-IK OH ◽  
JONG WAN KIM ◽  
MYEONGJU CHAE ◽  
JI-A JUNG ◽  
BYUNGJAE SO ◽  
...  

ABSTRACT This study investigated the prevalence of Salmonella enterica serovar and antimicrobial resistance in Salmonella Typhimurium isolates from clinically diseased pigs collected from 2008 to 2014 in Korea. Isolates were also characterized according to the presence of antimicrobial resistance genes and pulsed-field gel electrophoresis patterns. Among 94 Salmonella isolates, 81 (86.2%) were identified as being of the Salmonella Typhimurium serotype, followed by Salmonella Derby (6 of 94, 6.4%), Salmonella 4,[5],12:i:− (4 of 94, 4.3%), Salmonella Enteritidis (2 of 94, 2.1%), and Salmonella Brandenburg (1 of 94, 1.1%). The majority of Salmonella Typhimurium isolates were resistant to tetracycline (92.6%), followed by streptomycin (88.9%) and ampicillin (80.2%). Overall, 96.3% of Salmonella Typhimurium isolates showed multidrug-resistant phenotypes and commonly harbored the resistance genes blaTEM (64.9%), flo (32.8%), aadA (55.3%), strA (58.5%), strB (58.5%), sulII (53.2%), and tetA (61.7%). The pulsed-field gel electrophoresis analysis of 45 Salmonella Typhimurium isolates from individual farms revealed 27 distinct patterns that formed one major and two minor clusters in the dendrogram analysis, suggesting that most of the isolates (91.1%) from diseased pigs were genetically related. These findings can assist veterinarians in the selection of appropriate antimicrobial agents to combat Salmonella Typhimurium infections in pigs. Furthermore, they highlight the importance of continuous surveillance of antimicrobial resistance and genetic status in Salmonella Typhimurium for the detection of emerging resistance trends.


Author(s):  
Nabil Karah ◽  
Fizza Khalid ◽  
Sun Nyunt Wai ◽  
Bernt Eric Uhlin ◽  
Irfan Ahmad

Abstract Background Acinetobacter baumannii is a Gram-negative opportunistic pathogen with a notorious reputation of being resistant to antimicrobial agents. The capability of A. baumannii to persist and disseminate between healthcare settings has raised a major concern worldwide. Methods Our study investigated the antibiotic resistance features and molecular epidemiology of 52 clinical isolates of A. baumannii collected in Pakistan between 2013 and 2015. Antimicrobial susceptibility patterns were determined by the agar disc diffusion method. Comparative sequence analyses of the ampC and blaOXA-51-like alleles were used to assign the isolates into clusters. The whole genomes of 25 representative isolates were sequenced using the MiSeq Desktop Sequencer. Free online applications were used to determine the phylogeny of genomic sequences, retrieve the multilocus sequence types (ST), and detect acquired antimicrobial resistance genes. Results Overall, the isolates were grouped into 7 clusters and 3 sporadic isolates. The largest cluster, Ab-Pak-cluster-1 (blaOXA-66 and ISAba1-ampC-19) included 24 isolates, belonged to ST2 and International clone (IC) II, and was distributed between two geographical far-off cities, Lahore and Peshawar. Ab-Pak-clusters-2 (blaOXA-66, ISAba1-ampC-2), and -3 (blaOXA-66, ISAba1-ampC-20) and the individual isolate Ab-Pak-Lah-01 (ISAba1-blaOXA-66, ISAba1-ampC-2) were also assigned to ST2 and IC II. On the other hand, Ab-Pak-clusters-4 (blaOXA-69, ampC-1), -5 (blaOXA-69, ISAba1-ampC-78), and -6A (blaOXA-371, ISAba1-ampC-3) belonged to ST1, while Ab-Pak-cluster-6B (blaOXA-371, ISAba1-ampC-8) belonged to ST1106, with both ST1 and ST1106 being members of IC I. Five isolates belonged to Ab-Pak-cluster-7 (blaOXA-65, ampC-43). This cluster corresponded to ST158, showed a well-delineated position on the genomic phylogenetic tree, and was equipped with several antimicrobial resistance genes including blaOXA-23 and blaGES-11. Conclusions Our study detected the occurrence of 7 clusters of A. baumannii in Pakistan. Altogether, 6/7 of the clusters and 45/52 (86.5%) of the isolates belonged to IC I (n = 9) or II (n = 36), making Pakistan no exception to the global domination of these two clones. The onset of ST158 in Pakistan marked a geographical dispersal of this clone beyond the Middle East and brought up the need for a detailed characterization.


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