Horizontal transfer of antibiotic resistance genes in clinical environments

2019 ◽  
Vol 65 (1) ◽  
pp. 34-44 ◽  
Author(s):  
Nicole A. Lerminiaux ◽  
Andrew D.S. Cameron
Keyword(s):  
Antibiotic Resistance ◽  
Antibiotic Resistance Gene ◽  
Genetic Material ◽  
Antibiotic Resistance Genes ◽  
Extracellular Dna ◽  
Genetic Diagnostics ◽  
Antibiotic Resistant ◽  
Rapid Spread ◽  
Medical Crisis ◽  
Clinical Environments

A global medical crisis is unfolding as antibiotics lose effectiveness against a growing number of bacterial pathogens. Horizontal gene transfer (HGT) contributes significantly to the rapid spread of resistance, yet the transmission dynamics of genes that confer antibiotic resistance are poorly understood. Multiple mechanisms of HGT liberate genes from normal vertical inheritance. Conjugation by plasmids, transduction by bacteriophages, and natural transformation by extracellular DNA each allow genetic material to jump between strains and species. Thus, HGT adds an important dimension to infectious disease whereby an antibiotic resistance gene (ARG) can be the agent of an outbreak by transferring resistance to multiple unrelated pathogens. Here, we review the small number of cases where HGT has been detected in clinical environments. We discuss differences and synergies between the spread of plasmid-borne and chromosomal ARGs, with a special consideration of the difficulties of detecting transduction and transformation by routine genetic diagnostics. We highlight how 11 of the top 12 priority antibiotic-resistant pathogens are known or predicted to be naturally transformable, raising the possibility that this mechanism of HGT makes significant contributions to the spread of ARGs. HGT drives the evolution of untreatable “superbugs” by concentrating ARGs together in the same cell, thus HGT must be included in strategies to prevent the emergence of resistant organisms in hospitals and other clinical settings.

scholarly journals Extracellular DNA (eDNA): Neglected and Potential Sources of Antibiotic Resistant Genes (ARGs) in the Aquatic Environments

Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 874
Author(s):  
Periyasamy Sivalingam ◽  
John Poté ◽  
Kandasamy Prabakar
Keyword(s):  
Antibiotic Resistance ◽  
Health Risk ◽  
Genetic Material ◽  
Antibiotic Resistance Genes ◽  
Extracellular Dna ◽  
Antibiotic Resistant ◽  
Treatment Technologies ◽  
Environmental Bacteria ◽  
Global Threat ◽  
Potential Public Health

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.

scholarly journals Genome-wide correlation analysis suggests different roles of CRISPR-Cas systems in the acquisition of antibiotic resistance genes in diverse species

2019 ◽  
Vol 374 (1772) ◽  
pp. 20180384 ◽  
Author(s):  
Saadlee Shehreen ◽  
Te-yuan Chyou ◽  
Peter C. Fineran ◽  
Chris M. Brown
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Evolutionary Dynamics ◽  
Antibiotic Resistance Gene ◽  
Antibiotic Resistance Genes ◽  
Important Species ◽  
Fitness Advantage ◽  
Genome Wide ◽  
Clinical Environments

CRISPR-Cas systems are widespread in bacterial and archaeal genomes, and in their canonical role in phage defence they confer a fitness advantage. However, CRISPR-Cas may also hinder the uptake of potentially beneficial genes. This is particularly true under antibiotic selection, where preventing the uptake of antibiotic resistance genes could be detrimental. Newly discovered features within these evolutionary dynamics are anti-CRISPR genes, which inhibit specific CRISPR-Cas systems. We hypothesized that selection for antibiotic resistance might have resulted in an accumulation of anti-CRISPR genes in genomes that harbour CRISPR-Cas systems and horizontally acquired antibiotic resistance genes. To assess that question, we analysed correlations between the CRISPR-Cas, anti-CRISPR and antibiotic resistance gene content of 104 947 reference genomes, including 5677 different species. In most species, the presence of CRISPR-Cas systems did not correlate with the presence of antibiotic resistance genes. However, in some clinically important species, we observed either a positive or negative correlation of CRISPR-Cas with antibiotic resistance genes. Anti-CRISPR genes were common enough in four species to be analysed. In Pseudomonas aeruginosa , the presence of anti-CRISPRs was associated with antibiotic resistance genes. This analysis indicates that the role of CRISPR-Cas and anti-CRISPRs in the spread of antibiotic resistance is likely to be very different in particular pathogenic species and clinical environments. This article is part of a discussion meeting issue ‘The ecology and evolution of prokaryotic CRISPR-Cas adaptive immune systems’.

scholarly journals Effects of Sulfamethoxazole on Growth and Antibiotic Resistance of A Natural Microbial Community

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1262
Author(s):  
Jasmin Rauseo ◽  
Anna Barra Caracciolo ◽  
Francesca Spataro ◽  
Andrea Visca ◽  
Nicoletta Ademollo ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Microbial Community ◽  
Antibiotic Resistance Gene ◽  
Antibiotic Resistance Genes ◽  
Antibiotic Resistant ◽  
Emerging Compounds ◽  
Mixed Microbial Community ◽  
Natural Microbial Community ◽  
Community Growth ◽  
Animal Exposure

Diffuse environmental antibiotic and antibiotic resistance gene contamination is increasing human and animal exposure to these emerging compounds with a consequent risk of reduction in antibiotic effectiveness. The present work investigated the effect of the antibiotic sulfamethoxazole (SMX) on growth and antibiotic resistance genes of a microbial community collected from an anaerobic digestion plant fed with cattle manure. Digestate samples were used as inoculum for concentration-dependent experiments using SMX at various concentrations. The antibiotic concentrations affecting the mixed microbial community in terms of growth and spread of resistant genes (sul1, sul2) were investigated through OD (Optical Density) measures and qPCR assays. Moreover, SMX biodegradation was assessed by LC-MS/MS analysis. The overall results showed that SMX concentrations in the range of those found in the environment did not affect the microbial community growth and did not select for antibiotic-resistant gene (ARG) maintenance or spread. Furthermore, the microorganisms tested were able to degrade SMX in only 24 h. This study confirms the complexity of antibiotic resistance spread in real matrices where different microorganisms coexist and suggests that antibiotic biodegradation needs to be included for fully understanding the resistance phenomena among bacteria.

scholarly journals A Mechanism of Unidirectional Transformation, Leading to Antibiotic Resistance, Occurs within Nasopharyngeal Pneumococcal Biofilm Consortia

mBio ◽  
2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Santiago M. Lattar ◽  
Xueqing Wu ◽  
Jennifer Brophy ◽  
Fuminori Sakai ◽  
Keith P. Klugman ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Extracellular Dna ◽  
Antibiotic Resistant ◽  
Content Type ◽  
Serotype Replacement ◽  
Genes Encoding ◽  
Receptor Cross Talk ◽  
Or Genes

ABSTRACT Streptococcus pneumoniae acquires genes for resistance to antibiotics such as streptomycin (Str) or trimethoprim (Tmp) by recombination via transformation of DNA released by other pneumococci and closely related species. Using naturally transformable pneumococci, including strain D39 serotype 2 (S2) and TIGR4 (S4), we studied whether pneumococcal nasopharyngeal transformation was symmetrical, asymmetrical, or unidirectional. Incubation of S2 Tet and S4 Str in a bioreactor simulating the human nasopharynx led to the generation of Spn Tet/Str recombinants. Double-resistant pneumococci emerged soon after 4 h postinoculation at a recombination frequency (rF) of 2.5 × 10 −4 while peaking after 8 h at a rF of 1.1 × 10 −3 . Acquisition of antibiotic resistance genes by transformation was confirmed by treatment with DNase I. A high-throughput serotyping method demonstrated that all double-resistant pneumococci belonged to one serotype lineage (S2 Tet/Str ) and therefore that unidirectional transformation had occurred. Neither heterolysis nor availability of DNA for transformation was a factor for unidirectional transformation given that the density of each strain and extracellular DNA (eDNA) released from both strains were similar. Unidirectional transformation occurred regardless of the antibiotic-resistant gene carried by donors or acquired by recipients and regardless of whether competence-stimulating peptide-receptor cross talk was allowed. Moreover, unidirectional transformation occurred when two donor strains (e.g., S4 Str and S19F Tmp ) were incubated together, leading to S19F Str/Tmp but at a rF 3 orders of magnitude lower (4.9 × 10 −6 ). We finally demonstrated that the mechanism leading to unidirectional transformation was due to inhibition of transformation of the donor by the recipient. IMPORTANCE Pneumococcal transformation in the human nasopharynx may lead to the acquisition of antibiotic resistance genes or genes encoding new capsular variants. Antibiotics and vaccines are currently putting pressure on a number of strains, leading to an increase in antibiotic resistance and serotype replacement. These pneumococcal strains are also acquiring virulence traits from vaccine types via transformation. In this study, we recapitulated multiple-strain colonization with strains carrying a resistance marker and selected for those acquiring resistance to two or three antibiotics, such as would occur in the human nasopharynx. Strains acquiring dual and triple resistance originated from one progenitor, demonstrating that transformation was unidirectional. Unidirectional transformation was the result of inhibition of transformation of donor strains. Unidirectional transformation has implications for the understanding of acquisition patterns of resistance determinants or capsule-switching events.

scholarly journals In silico Assessment of the Genotypic Distribution of Virulence and Antibiotic Resistance Genes in Vibrio cholerae

2017 ◽  
Vol 16 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Nusrat Nahar ◽  
Ridwan Bin Rashid
Keyword(s):  
Antibiotic Resistance ◽  
Vibrio Cholerae ◽  
Resistance Gene ◽  
Resistance Genes ◽  
In Silico ◽  
Virulence Genes ◽  
Antibiotic Resistance Gene ◽  
Antibiotic Resistance Genes ◽  
Antibiotic Resistant ◽  
Genotype 2

Vibrio cholerae has long been reported as an important cause of death in developing countries. The study detected the virulence and antibiotic resistance gene of eight V. cholerae isolates through in silico tools. Cholera toxins, ctxA and ctxB were found in six isolates (75%). Seventy-five percent isolates were also found to be positive for zonula occludens toxin, zot which is known to increase the permeability by altering the tight junction of the small intestine. Accessory cholera enterotoxin ace, responsible for fluid accumulation, was detected in four V. cholerae strains. Seven isolates (87.5%) were positive for toxin-coregulated pilus, tcp which helps the bacteria to adhere to gut mucosa. Both ompW and toxR genes were found in 87.5% of the isolates. Twenty-five percent isolates harboured strA, strB, sulII, dfrA1, floR genes and SXT element demonstrating that they were multidrug-resistant (MDG) bacterium. One isolate was found to be positive for tetA gene while no erythromycin resistance gene, ermA and ermB was found. Virulence genes were found in all genotypes indicating that their distribution was not genotypeoriented while genotype 2 harboured no antibiotic resistance genes. This data helps to predict virulence genes associated with cholera and also demonstrates the presence of antibiotic resistance genes. Bacteria acquired the antibiotic resistance gene through natural process which cannot be stopped. So by analyzing the resistance pattern we can choose appropriate antibiotics. In silico study helps us to predict the antibiotic resistant genotypes and can easily identify antibiotic resistant strains which help us to treat cholera infections and reduce the morbidity and mortality rate of the infected individuals.Dhaka Univ. J. Pharm. Sci. 16(1): 77-85, 2017 (June)

scholarly journals Genomic Analysis of Global Staphylococcus argenteus Strains Reveals Distinct Lineages With Differing Virulence and Antibiotic Resistance Gene Content

2021 ◽  
Vol 12 ◽  
Author(s):  
Cosmika Goswami ◽  
Stephen Fox ◽  
Matthew Holden ◽  
Alistair Leanord ◽  
Thomas J. Evans
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Gene ◽  
Genetic Material ◽  
Clinical Manifestations ◽  
Antibiotic Resistance Genes ◽  
Genomic Analysis ◽  
Pathogenicity Islands ◽  
Type I ◽  
Virulence Determinants

Infections due to Staphylococcus argenteus have been increasingly reported worldwide and the microbe cannot be distinguished from Staphylococcus aureus by standard methods. Its complement of virulence determinants and antibiotic resistance genes remain unclear, and how far these are distinct from those produced by S. aureus remains undetermined. In order to address these uncertainties, we have collected 132 publicly available sequences from fourteen different countries, including the United Kingdom, between 2005 and 2018 to study the global genetic structure of the population. We have compared the genomes for antibiotic resistance genes, virulence determinants and mobile genetic elements such as phages, pathogenicity islands and presence of plasmid groups between different clades. 20% (n = 26) isolates were methicillin resistant harboring a mecA gene and 88% were penicillin resistant, harboring the blaZ gene. ST2250 was identified as the most frequent strain, but ST1223, which was the second largest group, contained a marginally larger number of virulence genes compared to the other STs. Novel S. argenteus pathogenicity islands were identified in our isolates harboring tsst-1, seb, sec3, ear, selk, selq toxin genes, as well as chromosomal clusters of enterotoxin and superantigen-like genes. Strain-specific type I modification systems were widespread which would limit interstrain transfer of genetic material. In addition, ST2250 possessed a CRISPR/Cas system, lacking in most other STs. S. argenteus possesses important genetic differences from S. aureus, as well as between different STs, with the potential to produce distinct clinical manifestations.

scholarly journals Characteristics of antibiotic resistant strains of Vibrio cholerae carrying SXT type integrative conjugative elements

2014 ◽  
Vol 19 (3) ◽  
pp. 34-39
Author(s):  
M. V Podshivalova ◽  
Yu. A Kuzyutina ◽  
I. B Zakharova ◽  
Ya. A Lopasteyskaya ◽  
D. V Viktorov
Keyword(s):  
Antibiotic Resistance ◽  
Vibrio Cholerae ◽  
Resistance Gene ◽  
Antibiotic Resistance Gene ◽  
Antibiotic Resistance Genes ◽  
Morphological Properties ◽  
Antibiotic Resistant ◽  
Volgograd Region ◽  
Resistant Strains ◽  
Integrative Conjugative Elements

In the paper there is presented a characteristics of antibiotic-resistant strains of Vibrio cholerae, isolated in the Volgograd region during the period of 1980-2000. There were studied cultural and morphological properties of the isolates, their biochemical activity, resistance to antibiotics of different classes, there was performed the detection of virulence genes and sequences of transmissible SXT-element. There was demonstrated the presence of different types of SXT in the content of the genome of the examined strains - SXT MO10 element with cluster of the antibiotic resistance gene sulII-strB-dfr18, SXT ET element carrying the sequences sulII dfrA1, and not having a resistance gene to aminoglycosides strB, and SXT S element with deleted cluster of antibiotic resistance genes.

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